Kenneth G. Kostka
Purple Martin Preservation Alliance (PMPA)*
*PMPA is now defunct, but has reorganized as
American Swallow Conservancy
Synopsis. Purple Martins cannot recognize their own nestlings before fledging except through association with a specific nesting cavity that is located by way of local topography, compass direction and surrounding visual cues. If the parents’ ability to recognize their cavity can be enhanced by augmenting the nest site, housing, entrance hole, and nesting cavity with distinctive, artificial visual and auditory markers, these markers could act as “associative cues,” allowing the martins to identify their nesting cavity and nestlings when moved to a new location, and thereby allowing several breeding pairs, along with their housing, nests, and nestlings to be transplanted. Several successful transplant attempts have been reported in the literature.
Table of Contents:
Preface –Overview of Current Conservation Efforts
Project Proposal – Transplanting Breeding Purple Martins
History of Purple Martin Colony Transplantation Attempts (updated 02/24/08)
Premise for Successful Transplantation
Project Planning and Design – Key Elements
Request for Permission to Move Adults, Nests, and Nestlings
Donor and Transplant Sites
Procedure to be Followed
Background of Purple Martin Conservation Efforts in Southwestern PA. Appendix A
Current Status of Purple Martins in Southwestern Pennsylvania Appendix B
History of Purple Martins in Southwestern Pennsylvania Appendix C
Purple Martin Preservation Alliance (PMPA) Conservation Efforts In a long-term effort to help the Purple Martin population in southwestern PA recover its former numbers and to establish new colonies, the PMPA has, since 1999, intensely managed or assisted in the management of almost every Purple Martin colony in Allegheny, Armstrong, Westmoreland, and Butler counties. These include the only colony in Armstrong Co. at Gastown Racetrack in Shelocta, which has grown from 6 to 28 pairs; the only colony in Westmoreland Co. at Zeglin’s Dairy Farm in Mammoth, which has grown from 12 to 26 pairs; the only three colonies in Allegheny county: the Butlers Golf Course colony in Elizabeth, which has grown from 6 to 18 pairs, the Youghiogheny Country Club colony in Buena Vista which has grown from 12 to 30 pairs, and Lock 4 colony in Natrona, which has grown from 1 to 3 pairs; as well as the following Butler Co. colonies: the Saxon Golf Course colony in Sarver, which has grown from 10 to 28 pairs, the Moraine State Park colony in Portersville that has grown from 18 to 32 pairs, and the Duke Snyder colony in Butler that has grown from 26 to 40 pairs.
These extensive efforts have included the development of an innovative emergency feeding program that has prevented large numbers of Purple Martins from dying of starvation during extended periods of poor spring weather. (Kostka, 2000, 2005, 2006)
Despite these efforts, and the fact that the PMPA has erected and managed additional housing at multiple sites in prime martin habitat, only two new colonies have been established in this eight year span – at the U. S. Army Corps of Engineers Lock and Dam facility in Natrona, PA, where three pairs bred successfully in 2006, and the Butlers Golf Course colony at Blythedale, where six pairs bred in 2006. For a more extensive description of the PMPA’s conservation efforts, see appendix A. Overall, Purple Martins remain scarce in southwestern Pennsylvania, according to the Breeding Bird Survey (Sauer, 2005), as detailed in Appendix B. The PMPA’s website, detailing additional efforts, can be found at http://www.purple-martin.org
Project Proposal – Transplanting Breeding Purple Martins
We propose a bold experiment designed to establish three new Purple Martin colonies. This experiment involves moving a small portion of the inhabited martin housing at already established colonies to a new location. If successful, this colony-establishment technique would be a major advance for Purple Martin conservation efforts. More colonies would make the overall population less vulnerable to predation, disease, natural disaster, and vandalism. Furthermore, this technique could be used to establish colonies in targeted areas where they can be closely monitored and managed for maximum reproductive success. Colonies located in “backyard habitats” tend to be more successful because “landlords” can conveniently trap non-native nest site competitors, offer emergency feedings, monitor nests, and conveniently perform other management tasks such as housing maintenance. This technique could also be used to move breeding martins out of harms way in the middle of the breeding season in emergency situation such as highway construction.
It has already been demonstrated that the nests of songbirds can be moved short distances with the parents continuing to care for the nestlings. (Peek, 1972) Breeding Tree Swallows quickly relocate and continue to care for their nestlings when their nest cavity is moved 5-10 feet. Winkler gradually moved two Barn Swallow nests approximately two miles, and three of the four parents continued to attend, successfully fledging all nestlings at the transplant site. (Winkler, 1990).
Purple Martins present a unique transplant opportunity because they are a cavity nesting species that utilize easily-accessed, human-supplied housing. Both parents typically sleep in the cavity with their nestlings until they are at least 14 days old (Brown, 1980), allowing the entire family to be confined by simply blocking the entrance hole after dark. Transplantation would involve confining multiple breeding pairs, along with their nests and nestlings inside their cavities at night, then moving the housing to the transplant site, and unblocking the entrances holes at daybreak, thus releasing the confined pairs.
While “trap and transport” or “stocking” is typically ineffective with songbirds because of their strong homing ability, we believe that, after an initial period of disorientation, which might involve temporarily returning to the donor colony, the martins will continue to care for their nestlings because of their large investment of reproductive energy, as well as an artificially enhanced ability to recognize their housing and nestlings. Once they have fledged their nestlings from the transplant site, at least some parents and nestlings should develop site fidelity and return to nest at the transplant site in subsequent seasons, thus establishing a new breeding colony.
History of Purple Martin Colony Transplantation Efforts
A search of the ornithological literature and other sources has revealed four attempts at Purple Martin colony transplantation; three of these transplants were apparently successful, and one was not. Three attempts involved trapping breeding pairs of Purple Martins inside their original nesting cavities along with eggs or young, then transporting the housing to a remote site. The fourth attempt involved moving only the housing, and allowing the martins to follow. Unfortunately, no detailed records could be found for any of the four transplants, beyond what exists here.
Case 1: The Nova Scotia Transplant of 1925
The following account appears on the Purple Martin Page of the Nova Scotia Museum of Natural History Website:
“The homing instinct of these birds is well developed, as illustrated by an unusual incident: On the night of 6 July 1925, I undertook to transplant two entire families of martins, two pairs of adults and their respective broods of five each, from Truro, Nova Scotia to Wolfville, Nova Scotia, [a distance of approximately 56 miles]. They were transported by auto, each family in its own compartment of a double nest box. On arrival at Wolfville about midnight the whole contraption was placed on a prearranged pole in my garden. The stoppers were then removed from the two entrances, all being quiet inside during that part of the operation. Next morning, considerably after daylight, the four adults emerged, circled about the garden a few times as though getting their bearings, and then disappeared and did not return to their nests. About two hours later a long-distance call from Truro informed me that two pairs of Martins were then circling madly about the top of the old nest pole and scolding vociferously. Seemingly without hesitation they had abandoned their helpless offspring in obedience to a blind urge to return home.” (Birds of Nova Scotia Website, 2007)
This account does not say what ultimately happened to the nestlings, but an anecdotal account found in a birdhouse building book written by a resident of nearby Ontario almost certainly refers to the same transplant attempt, and describes how the martin house was moved back to the original location, where the parents resumed care of the nestlings (Plewes, 1990).
“It seems that a Nova Scotia resident attempted to move his Purple Martin colony about 100 miles. The whole martin house was closed up after dark, with the birds inside, and transported overnight. When the birds were released the next morning, they seemed a little confused, but they soon had it all figured out. By lunch time they were all back at the ranch. Naturally, their apartment house had to go back to, and soon all was well again. It would appear a real estate deal includes your Purple Martins.”
Case 2: The Pennsylvania Transplant of 1899
In 1899, an ornithologist named Josiah Hoopes, transplanted a colony of Purple Martins from his back yard in West Chester, PA, to the grounds of the Philadelphia Zoo, a distance of approximately 21.5 miles east. The only* account of this reportedly successful transplant was published in the Wilson Bulletin over 100 years ago (Jones, 1899):
“Remarkable intelligence was exhibited by a colony of martins which were transferred from this place [West Chester, PA] to the Zoological Garden, in Philadelphia, a few days ago, the birds returning here and escorting their lost companions to the new home, where they occupy cozy quarters to the delight of the management of the garden and its patrons.
For many years the management of the Zoological Garden has been attempting to secure a colony of martins for the purpose of locating them in the institution, but every attempt met with failure. The birds would not build in the boxes erected and could not be coaxed to make their home in the Garden in any manner, notwithstanding the efforts of the management.
Josiah Hoopes, of this place, some time ago became interested in the matter, and being a lover of the birds, determined to assist the management of the Garden if possible in securing a colony. He had a fine one at his home and at once began arrangements for the removal of it to the new location, adopting a rather novel plan for the transfer. Early in the spring, a large box was prepared for the birds when they should return to his home after the winter in the south. The box was so arranged that it could be lowered from its pole at will, and above the entrance to each apartment in it was arranged a little sliding door which could be dropped, thus imprisoning the birds. The birds came at the usual time this spring and commenced the building of their nests in the new box. They were not disturbed, laid their eggs and in due course of time little martins made their appearance. This was a few days ago and the time was due for the experiment of moving them, depending upon the love the old ones bore their young for its success.
A dark night was selected for the removal and a representative of the Philadelphia institution was sent for. He came here and the home of the birds was invaded. The shutters closing the entrances to the home of the birds were dropped, but a few of them failed to work and [some of] the alarmed birds escaped from the box. The house was lowered from its pole and taken to the Zoological Garden, where it was erected in a new location, the managers hoping all would remain there.
Early the next morning after the birds were transferred [and the martins released] an unusual commotion was noticed about the box by the keepers in the Garden. The martins seemed to be holding a consultation and calling the role in their own manner. Then they grouped about the box and there was a lot of chattering among them as though they were deciding some question of great moment. After this, the entire colony of old birds, leaving the young in the box to care for themselves, rose in the air and flew away. There was consternation in the “Zoo” and it was decided that the attempt at removal [actually relocation] had been a failure.
An hour after the birds had left Philadelphia, there was a commotion on the Hoopes lawn. A large colony of martins were gathered there and they were chattering at a great rate. Occasionally, another bird would join the assemblage. Finally all the birds rose and disappeared in a flock. Before noon there was happiness at the ”Zoo” The martins had returned to their home and the colony was augmented by many new arrivals. The birds had returned for the ones which had escaped from their homes in the box the night before and had escorted them to their young. The birds are now located in the Garden and making their home their [sic] as though it were their original place of abode, and there is joy in the hearts of the managers.
The above clipping from a Philadelphia newspaper was sent by Mr. Frank L. Burns, and is of great interest in showing that wild birds can be transplanted . — [Editor, Lyns Jones, 1899]”
In an exhaustive attempt to locate additional details about this transplant, I have contacted several scientific institutions holding information related to Josiah Hoopes in their archives. Both the Smithsonian Institute and the Philadelphia Academy of Natural Sciences, which purchased Hoopes extensive bird skin collection, had letters to or from Hoopes, who was a rather prominent amateur ornithologist, but none of these letters dealt with the martin transplant. Neither could the Philadelphia Zoo Librarian, the West Chester Historical Society Archivist, or several West Chester historians find any additional documentation about the transplant.
*On August 21, 2007, I discovered a new source of information on the Hoopes transplant experiment that indicated it did not succeed. The following account appeared in “The Purple Martin and Houses for Its Summer Home” by J. Warren Jacobs. 1909. Gleanings No.5. p.38. (A fifth attempt was also discovered in this same source. It appears at the end of this section as Case 5: The Maine Transplant of 1908.)
“This experiment was tried in the zoological gardens at Philadelphia in 1889 [date incorrect] by Mr. Robert D. Carson, who, by means of a trap house, secured a colony of nine pairs with 32 young from the grounds of Mr. Josiah Hoopes, of West Chester, transporting them the distance of about 20 miles by train at night. When released next morning the old birds deserted the young and returned to West Chester. The temptation of the old home so close by proved too strong even for parental affection. Most of the young however, were successfully raised by hand feeding, being fed chiefly cockroaches, grasshoppers, crickets, mealworms, and “prepared food.” This is a mixture intended for insectivorous birds, and according to Mr. Carson was well liked by the nestlings and agreed well with them. It consists of “dried and ground beef heart, meal, ground zwieback, boiled and mashed white potatoes, grated raw carrot, and grated hard-boiled eggs.” Probably any similar mixture would answer equally well. A small colony resulted from this experiment which would probably have proved permanent but for the fact that additional houses were put up in West Chester, and after two years the colony deserted to the old neighborhood. Though only temporary success was achieved, the experiment is encouraging and points the way to ultimate success. For the above facts, I am indebted to Mr. Charles J. Pennock, of Kennett Square, PA.” -Henshaw, H.W. 1907. “Value of Swallows as Insect Destroyers” Circular No. 56 U.S. Dept. of Agriculture, Bureau of Biological Survey. as quoted by Jacobs, J. Warren. 1909. “The Purple Martin and Houses for Its Summer Home” Gleanings No. 5. p. 38
Case 3: The Houston, Texas Transplant of 1971
Gary Berger, of Houston TX, a member of the Purple Martin Conservation Association, submitted the following account titled “Relocating Martins” to the organization’s online Discussion Forum in 2006:
“[Colony relocation] has been successful. I did it [35 years ago]. Now, I don’t condone this practice, and it IS illegal, but I was young and dumb (16) and managed to trap and move about 6-8 pair (on nests, with eggs, which is the only reason it worked, in my opinion). Probably 3/4 stayed, which I guess means I was semi-successful. We had moved about 7 miles north [*correction: 2.73 miles NNE] in April of that year, so out of concern for my colony (I couldn’t leave the houses up), I lowered the houses to about 6 feet at dusk, threw a bait-cast net over the whole house, and transported it the next morning. It was 35 years ago, so I don’t have the exact records, but they DID stay, and I had martins every year after, at that particular site.” (Berger, 2006) *correction made on 9/5/07 as a result of new information. -ed.
In an exchange of private correspondence, I first asked Berger if any martins became entangled in the net while trying to escape. He replied:
As I remember, a couple of martins came out onto the porch of the compartment, but since the net was pretty taut around the house, that’s as far as they could go. (Berger, 2006, pers. comm.)
I asked him how he could be sure that they were the same martins at the new location. In other words, I asked him how he could be sure that the original martins hadn’t abandoned the house – and new martins moved in at the new site. He replied:
Take into account that this was 35 years ago. At the time of the transplant, I had been a landlord for about 4-5 years and had built my colony to about 7-9 pair (in a very tree encroached location, I might add), so I was devastated to learn we were moving right in the middle of martin season! My Dad was actually the one who suggested the transplant, so after preparing the new site for delivery, at dusk one evening, I lowered the house to about 7 feet and tried to account for all the residents as they entered for the night. (Was I 100%? maybe not, but I think I got most, if not all) Me and a friend threw a big net over the whole shebang, took off the house, stored it in my garage overnight, then took off early the next morning to the new site. As I said, I seem to remember some martins who had tried to escape being out on the porches, but for the most part I remember them just calmly waiting for this to be over.
We arrived at the new site, mounted the house, removed the net, and raised the house. At this point, my recollection is hazier, mainly because this was the morning of OUR move to the new house, so we left to go to work pretty much right away, leaving no time for any real observations. However, I DID have martins right away, and more importantly, I believe it was the same ones because of one simple fact – the eggs hatched! New martins would not have taken over the care and raising of abandoned nests and eggs, if that had been the case. Absent of banding, that is really the only proof I had. I also seem to remember taking a minute to check on the martins during each moving trip to the house, and actually seeing some. This also seems to point to the same martins, as I doubt I would have attracted new birds the first day. I really wish I had been more diligent in my observations, and had kept detailed notes and records, (although even back then I did nest checks and kept records) but at the time I didn’t think what I had done was that out of the ordinary, just another martin “NUT” trying to keep his colony!
So that is what I remember. I guess it is possible that there is an alternate explanation; maybe the transplanted martins abandoned the new site, new martins moved in immediately, took over the new nests after ditching the old eggs, laid their own eggs, and successfully fooled me into believing that the originals had stayed! A lot of ifs, and if it wasn’t 35 years ago! (Berger, 2006)
Additional information about this transplant was obtained from Berger on 9/5/07. While Berger first estimated the distance between the two sites to be about 7 miles, I calculated the actual (air) distance between the two transplant sites to be only 2.73 miles, using my DeLorme Street Atlas map program and the two street addresses supplied by Berger. Also, while Berger first remembered the transplant attempt as having occurred in April, he later recalled that it occurred in early May. I attempted to confirm that the transplanted nests had eggs (as opposed to nestlings), and Berger responded “I am almost certain of the eggs…this move was around May 1st, and most of my first hatches occur around May 6th, even to this day……but I can’t guarantee that there were no babies at the time of transfer. I am sure I kept records of some sort, but they are long lost, and I am going on memory as far as number of pair and the existence of eggs.” (Berger, 2007). Berger added that the martin house was a 12 room wooden house on a telescoping pole, and that he had installed another pole at the transplant site several days in advance of the move. No photographs of the transplant house exist. As best I could determine (based on photographs of later martin houses built by Berger), the transplant house was not designed to be opened for nest checks, meaning that a flashlight and dental mirror (or some similar device) would have had to be used to conduct nest checks. Whereas the donor site was very tree-encroached, the transplant location was very open – a brand new subdivision with no trees. (Berger, 2007)
After studying all of the available facts and circumstances of this transplant attempt (and taking into account my own 2007 transplant attempt experience), it is my opinion that the Berger transplant attempt failed, and only appears to have succeeded. It seems most likely that the martins abandoned their nests when the house was moved, and that the house was recolonized (either by new martins or the same martins) at the new location. It is unlikely that nesting martins would stay with their eggs during such a traumatic and disorienting event, especially when one considers that, at the egg stage, martins typically have time to renest. During our own [PMPA] transplant attempts, martin pairs abandoned even their live, 10-12 day old nestlings over 85% of the time, when transplanted. Martins are abundant in Texas, and a well-managed martin house in a perfect location would likely have attracted martins very quickly. Even Berger states that “the new location was PERFECT for martins…new subdivision, no trees.” (Berger, 2007)
It’s unfortunate that Berger did not take time to observe how the martins behaved after being released at the new site. He states “We arrived at the new site, mounted the house, removed the net, and raised the house. At this point, my recollection is hazier, mainly because this was the morning of OUR move to the new house, so we left to go to work pretty much right away, leaving no time for any real observations.” (Berger, 2006) Unfortunately, none of the martins were banded and there are no nesting records to examine. It is also possible that Berger’s martins abandoned their nests and flew back to the original site, where they found their housing was gone (and were effectively displaced), then began to search for new housing and settled into the same house at his new location, simply because because it was the nearest available housing. They would not have been able to recognize their own nesting compartments and eggs, and would have been forced to “start over” at the new location. If that was the case, then even though the transplant technically failed, the same end was achieved, because a colony of martins was re-established at the new site by displacing a nearby colony and forcing them to recolonize the housing at the new location.
Case 4: The British Columbia Transplant of 1987
In 1987, six pairs of Purple Martins nesting in the bilge pump holes of the decommissioned Canadian destroyer Chaudiere, were successfully (although unintentionally) transplanted approximately one mile when the ship was moved across Esquimalt Harbor during the summer. (Palmateer, 1995). The account, written by Calvor I. Palmateer, Director/Curator of the Sidney Museum, Marine Mammal & Historical, states:
“[On] May 6, 1987, there were six pairs of Purple Martins nesting in the holes in the sides of the ship. I have been told the holes are exits for bilge pumps. They are about ten meters from the ocean’s surface. The holes are circular and extend up at a slight angle about 30 cm into the ship. At the top end is a ball that prevents wave action in rough seas from washing water back into the bilge pumps. There are five holes down each side. The six pairs nested in holes down both sides…During the summer, the ship was moved [1.1 miles] across the harbor and the birds went with it, as far as I could tell, with no ill effect. All the pairs raised young, but I never had a chance to count them all.”
I contacted Calvor Palmateer for more information about this transplant, and he informed me that most of the males of the breeding pairs were ASY. He also stated that the ship maintained the same compass orientation when moved across the harbor, perhaps making it easier for the martins to locate their correct nesting cavity. Finally, he informed me that the ship was returned to its original dock several weeks later, meaning that the martins were actually successfully transplanted twice!
Case 5: The Maine Transplant of 1908
*On August 21, 2007, I discovered yet another historical transplant attempt. The following account appeared in a publication titled “The Purple Martin and Houses for Its Summer Home” by J. Warren Jacobs. 1909. Gleanings No.5:
“Effect of Removing to a New Location, a Martin House with the Parent Birds and Nestlings” During the summer of 1908, correspondence with Mr. Daniel C. Robinson, Boston Mass., led to a promise on my part to furnish a few young Martins to be reared in his birdhouse at his summer place, near Manchester, Maine. Before the time came to ship the youngsters, Mr. Robinson had taken an extended automobile trip through several counties in Maine, discovering several breeding colonies of Martins, one of which he purchased and removed to his home place. The result of this experiment I give herewith, quoting in full from that part of Mr. Robinson’s letter dated November 25, 1908: ‘At your suggestion, I arranged with the owner of a house full of Martins, buying the whole outfit, and had them brought by automobile in the night to my premises and set upon a pole. In the morning, the netting being removed, seven or eight birds flew away, some old, and, I think, some young ones. The rest, about twenty-five, I took out and undertook to bring up by hand, placing them in boxes where I could get at them conveniently. For about three days I was obliged to force their mouths open and feed them with grasshoppers and a mixture of bread crumbs and hard-boiled eggs. After a while a man from a neighboring town brought me three more, and a few weeks later I obtained ten more. I treated them in about the same way. After about a week they began to die with something like pneumonia, that is, they would show signs of distress in breathing and have a shortness of breath, like panting. They would live for about three days after these attacks. I wrote to a bird dealer in Boston for advice regarding food, and he sent me a supply of prepared food for soft-billed birds. They seemed to thrive much better on this diet, although by this time there were left only about ten. I fed them a very few grasshoppers, but mostly the prepared food and occasionally a few house flies. They became so tame that they would fly up into the trees, and about the buildings, returning to our hand or their box to feed, but one by one they contracted the fatal disease and dies like the others. The few birds that escaped during the process lingered about the premises for a time, and I have faint hopes of their returning.”
A disaster of this magnitude to the Purple Martin is to be deplored, especially in a section of the country where the success of every brood is needed to replenish the species. Here are about forty young Martins, most of which perished after being taken from the care of the parent birds, at a time and under such circumstances, that the parents hardly attempted to rear second broods. Now these forty nestlings would have gone far towards replenishing the former range of the species upon their return north in 1909. Mr. Robinson spared no expense and went to much trouble in his effort to transplant this colony of Martins, but has probably come so near failure that I shall hesitate to suggest the plan again.
Neither distance or direction is mentioned in this account, but based of the fact that the author says “Mr. Robinson had taken an extended automobile trip through several counties in Maine, discovering several breeding colonies of Martins, one of which he purchased and removed to his home place,” it seems reasonble to conclude that the transplant distance was at least 25 miles, probably longer.
Case #1 Nova Scotia: 2 pairs moved 56 miles ESE. Transplant failed
Case #2 Pennsylvania: 9 pairs moved 21 miles east. Transplant failed
Case #3 Texas: 6-9 pairs moved 2.73 miles north. Transplant (probably) failed
Case #4 British Columbia: 6 pairs moved 1 mile NW. Transplant succeeded.
Case #5 Maine: 6-7 pairs moved 25+(?) miles Transplant failed
*all red text is the result of new information obtained after 8/1/07 (after project was carried out)
It would appear from the summary above that the transplants succeeded when relatively larger colonies were moved relatively shorter distances. In both the Pennsylvania and Nova Scotia transplants, the martins flew back to the original colony site when transferred and released. In the Pennsylvania account, the martins then returned to the transplant site, apparently after concluding that their housing, nests, and young were indeed at the new location.
The success of the transplants should be defined not only by whether or not the relocated martins fledged their young at the transplant site, but by whether or not martins returned to the transplant site to breed the following season. The ultimate goal was not to have the martins fledge their young at a remote site, but to establish a new colony site. If the martins fledged their young but none returned the following year, the experiment must be deemed a failure.
In the case of the Texas transplant, a colony was established. Berger states that “I had martins every year after, at that particular site.” (Berger, 2006) No “year-after” information could be found for the Pennsylvania transplant. The Philadelphia Zoo had no information in their archives about Purple Martin colonies on their grounds.
Unfortunately, detailed records were not kept for any of the transplants.
Premise for Successful Transplantation
Purple Martins with young in the nest have made a very large investment of time and energy in their reproductive attempt. They instinctively know it is too late in the season for a re-nesting attempt, would only fail to care for their transplanted nestlings under three possible circumstances:
Reason #1: Extreme Fright/Self Preservation. If the martins believed that their own lives were highly imperiled, they might abandon the nesting attempt in order
to “live and breed another day.” A transplant is unlikely to cause this reaction because the martins would not be handled during the transplant, simply confined
inside their nesting cavity at a time when they would normally be inside anyways. Purple Martins have come to live in close association with man, using
man-made structures for nesting. Breeding adults are routinely trapped and handled for banding or a variety of other research purposes when
they have nestlings, and they do not abandon their nestlings under these circumstances. One western researcher put it best when he stated, “I don’t think they
would abandon the young because they consider their lives in danger. When I think about all we put the Sacramento birds through, and they just go on feeding
their young, it is really amazing. We… capture them in hoop nets in which they often struggle and distress call as they are being extracted, then put them in a
paper bag for a while where they often struggle a bit more, then hold them up to be weighed where they sometimes struggle again, then pull them out of the bag,
band both legs, measure wings, bill, legs, and tail , and the tail measurement they definitely do not like, then, put them in a very firm grip and bend their head
over to the side and insert a hypodermic needle into their jugular vein and draw blood, take a few flash photos in their face, then release them, and they do not
abandon the site, rather they continue to feed their young, often within the hour, and then they return to the site again the following year.” (Kostka, pers. comm.)
Reason # 2: Can’t Relocate Transplanted Housing after Homing Purple Martins have an excellent homing ability and are capable of returning to their nesting colony when captured and released hundreds of miles away (Southern, 1959) What is not known is whether, after being released and returning to the original colony site (homing), they could successfully relocate their housing at its new location. In the Pennsylvania transplant, they apparently were able to, even though it was 21.5 miles distant. While martins are usually familiar with a substantial area around their colony site and would not be expected to have a problem returning to any specific point within that “area of familiarity,” it is possible that if transported too far away, they might not be able to relocate their housing. Several measures will be taken to insure they can relocate their housing. First, the transplant site will be located near a large body of water that can be used as a navigational landmark. Second, Purple Martins vocalizations will be broadcast over an outdoor loudspeaker in the direction of the donor site to act as a sound beacon. Third, some adults (ASY), who presumably possess advanced navigational skills and knowledge of the area due to their increased age and experience, will be included in the long distance transplants. Lesser experienced subadults can then follow these ASY parents back to the transplant site.
Reason #3: Don’t Recognize Nestlings. If the parents fail to care for their nestlings at the transplant site, it would most likely be because they simply do not recognize them as their own, since Purple Martins typically associate their young with a location. Six pairs of breeding Purple Martins did, however, stay with their nests in the bilge holes of a ship when it was pushed by tugboats to a location at least one mile away (Palmateer, 1990), indicating that the parents must have relied on the visual cue of the ship to locate their nestlings, and were willing to continue raising their nestlings in a new location. Likewise, we believe that martins nesting in traditional housing can be conditioned to associate their nests with a series of visual and auditory cues, so that when the location of the housing is changed, the martins can recognize their nest cavity by way of these “associative cues,” just as the martins nesting in the bilge holes of the Canadian ship came to associate their nests with the ship.
Project Planning and Design – Key Elements
Enhanced Site/Housing/Entrance Hole/Cavity Recognition (SHECR) Program
Purple Martins cannot recognize their own nestlings prior to fledging. (Brown, 1997). They rely on nest location and surrounding yard cues to find their own nest and insure that they are caring for their own nestlings. An unrelated nestling placed into a nest with young of approximately the same age will readily be adopted by the parents (Kostka, 2004). This association with location would explain why the transplanted Pennsylvania and Nova Scotia martins, when released, flew back to the exact spot where their nestbox had previously been located. Therefore, if martins were to abandon their nestlings at the transplant site, it could be argued that the most likely reason would be because they associate their nestlings primarily with a location, and that when the nestlings are placed in a new, distant location, the parents do not recognize them as their own. If this is the case, then it would follow that if the martins could be conditioned to associate their nestlings with an artificial series of very distinctive visual and auditory cues, then they would recognize their nestlings even at a different location and continue to care for them.
If the immediate area around the housing, the housing itself, the individual nest cavity entrance holes, and the nest cavity itself were made to appear unmistakably unique several weeks prior to the transplant, creating an “island of familiarity,” then the parents might be artificially enabled to recognize their housing, nest compartment, and nestlings in a new location when the housing is moved, assuming all the associative cues were moved to the transplant site at the same time, placed in the same configuration around the housing, and presented to the displaced martins upon their release. The cues would be used for enhanced Site, Housing, Entrance hole, and Cavity Recognition (SHECR), as described below.
Enhanced Site Recognition. Since martins typically orient to their nests by way of surrounding visual cues such as trees, fences, and buildings, we propose to install a series of stark visual cues around the martin housing at the donor site, cues that can be easily moved along with the housing to the transplant site and erected in the same pattern around the housing. These artificial yard cues would not only allow the martins to orient to their proper compartment at the new location, but would also serve as “associative cues,” allowing the martins to “recognize” the general nesting site and acknowledge the young as their own. The primary visual cue would be a large brightly colored tarp laid out on the ground around the base of the martin housing pole. This tarp would serve as an especially stark visual cue (and beacon) from high in the air. A simple three foot high square rope fence with different colored strips of cloth or plastic on each side would also be placed around the housing at the edge of this colored tarp, creating an unmistakable island of familiarity.
In addition, two auditory cues would be used to help the martins recognize their site. These would be two distinct types of music played on a portable stereophonic compact disc player (or boombox) while attending the donor sites for management purposes. Of these two “sound cues,” one would be played exclusively when the martins are being provided with supplemental feedings in the form of crickets, mealworms, or scrambled egg. The other sound cue would be played whenever present at the site during routine management tasks or observation. Broadcast Purple Martin vocalizations (discussed below) could be considered a third auditory recognition/association cue.Finally, the colony manager (landlord) himself will be a visual associative cue. The colony manager will wear a brightly colored jacket, shirt, or hat when providing supplemental/emergency feedings and when performing routine management tasks at the donor colony, and will then be present during the release at the transplant site wearing the same conspicuous clothing and offering supplemental feedings (discussed below).
Enhanced Housing Recognition. In an attempt to make the housing itself appear unique and distinguishable from all other martin housing, as well as to provide more associative cues, several multi-colored (red, blue, yellow, white) martin decoys will be mounted on the roof of the housing at least several weeks prior to the transplant; these unique “martins” will hopefully come to be accepted as very recognizable “members” of the colony. When the housing is moved, these decoys will appear to be non-abandoning “martins” and might help to influence the real martins to stay. Small pieces of mirror will also be placed just inside unused entrance holes. Martins seeing their reflections in these mirrors in the weeks prior to the transplant, will also perceive them to be non-abandoning members of the colony when the housing is moved.
Enhanced Nest Cavity Entrance Hole Recognition. In order to allow the martins to identify their own individual compartment or gourd within the martin housing, the area around the entrance hole and the porch of each occupied compartment or gourd will be marked with a unique bright color. The colors used will be yellow, orange, red, blue, green, and brown (all light shades). As martins enter and exit their nest cavities in the weeks prior to the transplant, they will come to associate a color with their compartment or gourd, and be able to easily identify and orient to their proper nest cavity when the housing is moved.
Enhanced Nest Recognition. Several small colored objects or materials will be discreetly inserted into the nest cavities at least one week prior to the transplant. They would be the same color as the entrance hole area, and would help to identify the nest cavity to their parents. The nests would be closely monitored when they were inserted, so as to be sure they would not unduly alarm the parents and cause nest abandonment.
Social Attraction. Purple Martin vocalizations will be broadcast on an outdoor loudspeaker during the release at the transplant site, encouraging the martins to adopt new site by creating the illusion that other nesting martins are present, just like at the donor site. Purple Martin decoys will also be deployed on nearby martin housing, and mirrors will be strategically placed to enhance the illusion of other breeding martins. The broadcast vocalizations will also act as a homing beacon, helping martins to orient to the transplant site.
Supplemental Feeding cues. Martins from all sites are trained to accept supplemental and emergency feedings, an innovative management technique that has not only saved hundreds of martins from starvation during extended periods of poor spring weather (Kostka, 2000, 2005, 2006), but that has undoubtedly increased breeding success since martins will also feed the items to their nestlings later in the season during poor weather. The transplanted martins may be more likely to stay at the transplant site if it is made apparent that they will have access to an unlimited supply of food for nestlings. We would not only have the same stationary feeder set up at the transplant site, but we would offer tossed food (another associative cue) as the martins are released.
Summary of all visual and auditory associative cues presented to martins during their release:
1. Inside cavity color visual cue
2. Colored Porch/Entrance hole visual cue
3. Colored decoys on housing roof, unused porches, or gourd arms visual cue.
4. Mirrors inside unused entrance holes visual cue
5. Martin housing visual cue
6. Colored tarp on ground around base of pole visual cue
7. Rope fence with colored material around tarp visual cue
8. Stationary feeder with decoys visual cue
9. Landlord supplemental feeding activity visual cue
10. Supplemental feeding music audio cue
11. Purple Martin generic vocalizations audio cue
12. Other martin housing with decoys/mirrors visual cue
13. General management/landlord present music auditory cue
14. Landlord with distinctive clothing visual cue
15. Other released martins visual cue
Distance between Donor and Transplant site: Distance might be the element limiting successful transplantation. While martins can readily home in on their nesting site (Southern, 1959), apparently because of their long association with that specific area and whatever mechanisms that allow them to find it easily, it may more difficult for them to orient to the transplant site, which the martins may have no close association with. The Pennsylvania transplant site was 21.5 miles away from the original colony site, the Texas transplant was 7 miles away, the British Columbia transplant 1 mile away, and the Nova Scotia transplant site 56 miles away. Martins are familiar with an area around their colony site, and likely become increasingly less familiar with the area as the distance from the site increases, making it increasingly more difficult to locate any specific point they may wish to find outside this area of familiarity. Since the three reportedly successful transplants were within 21.5 miles of the original colony site, we propose transplants at distances of approximately 3, 10, and 20 miles.
Purple Martins are an extremely flighted bird, often visiting other colonies, and capable of traveling great distances. One noted ornithologist wrote “These birds travel over wide expanse in quest of food. . .and during their summer stay in this region, they no doubt roam over the whole county.”(Jacobs, 1909). One bander reports spotting an SY-M at multiple colonies over a period of six weeks: first at Mission Beach, WA on 25 May, 2003; then 36 miles NNE at Ship Harbor, WA on 07 June, 2003; then again 20 miles SSW at English Boom, WA on 23 June, 2003; and finally 16 miles SSW back at Mission Beach on 14 July, 2003. (Kostka, pers. comm.) Several regular visitors to the Natrona, PA colony in 2005 were also spotted at colonies near Lake Arthur, 23-35 miles distant. The nesting SY-M at Natrona was seen at the Saxon Golf Course colony, which is 8.7 miles north on at least two occasions when he had young in the nest (Kostka, 2005). Doppler radar technology has demonstrated that Purple Martins at premigratory roosts range as far as 60 miles from the roosting area during daily foraging trips. (Russell, K and S. Gauthreaux, 1999). Martins are likely familiar with a large area around their nesting site, and capable of navigating the area between the donor and transplant sites without problems.
Location of transplant sites. It is important that the transplant site be good martin habitat since parents will need to find sufficient food to raise their nestlings. The long-distance transplant sites are near large lakes that should provide an ample amount of flying insects. Additionally, since birds use topographical landmarks for navigation (Wallraff, 1999), these large bodies of water should also help the martins relocate their displaced housing if they initially choose to return to the donor colony upon release. Birds traveling at an altitude of 3000 ft. have a 60 mile view of the landscape. Since Purple Martins are aquaphilic (Hill 1988), it is very likely that the martins, especially ASY individuals, would have visited these lakes at some point in their travels, making them part of their “familiar area map” (Baker, 1982), and allowing them “to navigate successfully from places that they have previously visited on the basis of a memory of familiar landmarks” (Holland, 2003).
Age of Nestlings. No nestling ages are given for the Pennsylvania, Nova Scotia, or British Columbia transplants, and the TX transplant involved eggs. No nestlings should be older than 14 days on the evening of the transplant. This is because it is important that both parents be confined in the nesting cavity for transport to the transplant site, and the male parent sometimes begins to sleep in nearby trees after the nestlings reach approximately 14 days old (Brown, 1980). Also, the parents may return to the donor site on the morning of the transplant leaving the nestlings unattended for extended periods of time. However, Purple Martin nestlings and eggs are capable of enduring frequent and prolonged (1-9 hours) periods of parental inattendance (Kale, 1964). Exposure would not be a problem since the transplants would only be conducted on warm sunny days in late June or early July.
Weather conditions. The weather forecast will be closely monitored as the intended transplant date approaches. Cool or rainy weather might needlessly stress both the parents and nestlings. Also, since birds use the sun’s azimuth as a compass for navigation (Wallraff, 1999), a cloudy day might impair the martins ability to travel between the donor and transplant sites.
Age of Parents (SY vs. ASY) to be Transplanted. SY (first breeding-year parents) would be the best candidates for transplant because they would not yet have developed as strong of a connection to the donor site as ASY parents. Once martins have bred successfully at a particular site, they develop “site fidelity” and usually return to that site again the following season to breed. (Allen, et al, 1952) Since most martins breed for the first time as SY’s, and since most breeding attempts are successful, it follows that, typically, most ASY parents would have already fledged nestlings in previous seasons at the donor sites, thus developing site fidelity there. Therefore, it is possible that even if all parents successfully fledged their nestlings at the transplant site, the ASY individuals might attempt to return to breed at the donor site in subsequent seasons. SY individuals, on the other hand, would be more likely to return to the transplant site in subsequent years, because they will have successfully fledged their first and only nestlings there, thereby developing site fidelity to the transplant site.
Nevertheless, it might be advantageous to have some ASY individuals included in the transplant attempt for several reasons. First, they are likely to possess superior knowledge of the area around the transplant site because of their age and experience. While no parents are expected to experience problems homing to the donor colony (Southern, 1959), it is unknown whether or not, having homed, they will be able to navigate back to the transplant site. Older (ASY) individuals are more likely to have an extensive knowledge of the area between the donor and transplant sites, and since a displaced colony appears to travel as a group (Kostka 2005, Jones 1899), SY parents could follow ASY individuals back to the transplant site. It is possible that the Pennsylvania transplant worked while the Nova Scotia transplant did not because older, more experienced individuals in the Pennsylvania colony guided the colony back to the Philadelphia Zoo site after homing back to the West Chester colony site.
The second reason that is might be advantageous to include ASY parents in the transplant is their advanced parenting skills. ASY parents have higher reproductive success. (Hill, 1997) Their superior parenting skills could mean that their attachment to their nestlings is stronger, preventing them from abandoning their young, even in a stressful situation like relocation. Since martins are a social bird, SY parents might be convinced to stay with their nestlings if they witness ASY parents attending nestlings at the new site. It should be noted that pairs often consist of an ASY male and an SY female.
Number of pairs transplanted: In all three successful transplants, six or more pairs of martins were relocated. In the only failed transplant, only two pairs were moved. Therefore, it seems reasonable to conclude that a larger number of pairs may be more likely to result in successful transplantation. Not only might the presence of a larger number of martins give all martins present more confidence, but the presence of even one or two pairs of non-abandoning adults may encourage other displaced adults to stay at the transplant site and attend their young. Therefore, we propose that the transplant include up to 6 pairs.
Moving all pairs vs. a small percentage of pairs. It should be noted that in all four transplant attempts, all of the nesting pairs from the donor colony were moved to the transplant site. However, we propose to move only a small portion of the nesting pairs (25% or less) from the donor colonies to the transplant sites in order to establish new colonies. Nonetheless, it could be argued that moving all pairs might be more successful since martins returning to the donor colony would then find no martin housing or nesting martins present to distract them from returning to the transplant site.
Request for Permission to Move Adults, Nests, and Nestlings
We request a special use permit to move Purple Martin housing containing six breeding pairs of Purple Martins, along with their nests and nestlings, from each of three separate donor colonies, distances of 3.1, 10.5, and 19.3 miles to the transplant sites as described below. These moved pairs would represent only a small fraction (25% or less) of the breeding pairs present at the three donor colonies so that no colony would be being placed in jeopardy. Furthermore, we are confident that if the relocated pairs fail to attend their nestlings at the transplant sites, then simply moving the housing back to its original location will prompt parents to resume care of their nestlings, since martins typically do not abandon the site of a breeding attempt that appears to have ended in failure for at least 24 hours. (Pewes, 1990; Kostka, unpub.data)
If, on the first transplant attempt, no parents were to continue caring for their nestlings at the transplant site, and if these parents were to abandon their nestlings even after the housing was moved back to the original site, all other transplant attempts would be aborted.
Exact dates for transplants cannot be given since the onset of egg-laying is weather-dependent, however all transplants will occur between June 15, 2007 and July 15, 2007.
Addresses of donor and transplant sites, along with names of all individuals appear below. We are varying the transplant distance, but the longest transplant would be 19.3 miles, since no evidence that a transplant longer than this distance has succeeded.
Please note that all pairs would be moved inside the martin housing along with their nests, nestlings, and any eggs.
Transplant attempt #1: We request permission to move up to six pairs nesting in single-unit gourds a distance of 3.1 miles NW, from the Moraine State Park colony at McDanels Launch, Portersville, PA (a 32 pair colony) to the property of Bob Allnock, Grant City Rd, Portersville, PA, a site consisting of a large field and a pond. One pair of Purple Martins bred successfully there in 2003.
Transplant attempt #2: We request permission to move up to six pairs nesting in single unit gourds a distance of 10.5 miles west, from the property of R. Wood, Shelocta, PA (a 28 pair colony) to Crooked Creek Park, Ford City, PA, a site next to a large lake. Purple Martins have been spotted here consistently over the past few seasons.
Transplant attempt #3: We request permission to move up to six pairs nesting in a house or gourds a total of 19.3 miles NNW from the Zeglin Dairy Farm (a 26 pair colony) to the property of Jeff Hunt in Export, PA, a site 3000 ft. from Beaver Run Reservoir, an expansive body of water with abundant food for the feeding of martin nestlings.
Names, addresses, phone numbers, and map coordinates of all donor and transplant sites:
Donor Colony #1: Moraine State Park
McDanels Launch, North Shore
Portersville, PA 16051
N 40 58.007 W080 07.457
Transplant Site #1: R. Allnock
Grant City Rd.
Portersville, PA 16051
N 40 59.287 W080 10.605
Donor Colony #2: R. Wood
RD 2, Rt 210
Shelocta, PA 15774
Coordinates: N 40 42.602 W079 18.520
Transplant Site #2: U.S. Army Corps of Engineers
Crooked Creek Lake
Mike Mazzocco, Park Ranger
114 Park Main Rd.
Ford City, PA 16226
Coordinates: N 40 42.841 W079 30.840
Donor Colony #3: Zeglin, L.
Zeglin Dairy farm
Mount Pleasant, PA 15666
Coordinates: N40 11.576 W079 28.179
Transplant Site #3: Jeff Hunt
176 Paradise Dr.
Export, PA 15632
Coordinates: N40 27.417 W079 35.478
Procedure to be Followed:
1) Allow Purple Martins to claim the housing and build nests at donor colonies. After martins are committed to breeding in the housing, begin enhanced SHECR Program (Site, Housing, Entrance hole, and Cavity Recognition program) as described on pages 10-11. Continue as martins lay and hatch eggs. Gradually lower housing as transplant date approaches, so that confinement of martins in their cavities is more easily accomplished. Monitor nests bi-weekly to track age of nestlings. Trap and band all parents at least 3-4 days prior to transfer date. Nestlings must be no older than 14 days on the day of the transplant. Monitor weather predictions. Transfer must occur during a period of average to above average temperatures to avoid stressing nestlings that may be temporarily unattended and to make navigation easier for adults.
2) At dusk on the evening of transplant, monitor the housing as the parents enter for the night and confirm that all parents enter compartments. After dark, quietly approach martin housing and block entrance holes. Gently and quietly remove housing from pole. Drive housing to donor site and immediately install (with entrances still blocked) on pre-installed pole, in the same compass orientation. Also, remove all visual cues from donor site and arrange them in the same configuration around the housing at the transplant site.
3) Begin playing Purple Martin vocalizations at low volume on outdoor loudspeaker at approximately 5:00 AM. These vocalizations will not only help create the illusion of colony activity, but will also act as an orientation beacon to the released martins. Insure that all other visual cues (page 14) are present in the proper configuration. Shortly after daybreak, unblock entrance holes and videotape all releases so that the presence of all parents can be confirmed, and for future review. The release may be staggered, with one or two pairs liberated at a time to avoid confusion or panic. Supplemental feeding will be offered by the landlord, wearing the same unique clothing worn all season at the donor site prior to the transplant, and playing the same auditory feeding cue. All video and audio associative cues will be presented, re-creating the “island of familiarity” and allowing parents to recognize their nest cavities and nestlings.
4) Monitor housing and martins with a high power spotting scope and binoculars to insure that the parents are feeding and attending their nestlings. Since some martins may leave and return to the donor site, one person will go to the donor site to monitor and observe any returning martins. It is believed that once the martins assess the situation at the donor colony and confirm that their housing and nests are no longer present, they will return to the transplant site to attend their nestlings. Continue to present all cues.
5) If, within 12 hours after the release time (approximately 6:00 PM) the martins have not resumed feeding their nestlings at the transplant site, the martin housing will be transferred back to the donor colony, where the nests will be closely monitored with binoculars and spotting scopes. Parents would be expected to resume feeding of their nestlings, since martins typically remain at the site of an unsuccessful breeding attempt for at least 24 hours. Any nests where parents have not resumed feeding nestlings by 7:00 AM the following morning will be considered abandoned, and the nestlings will be fostered into existing Purple Martin nests at the donor colony or the Saxon Golf Course colony, 839 Ekastown Rd., Sarver, PA, with young of similar ages, and monitored every other day for one week. Breeding adults at this colony would be provided with supplemental feedings to compensate for the increased number of nestlings. Nestlings will be periodically weighed to insure they are at the proper weights (Hill, 1994). Martin nestlings properly fostered into Purple Martin nests have a 100% survival rate (Kostka, 2005). Any nestlings not successfully fostered into existing nests will be taken to a licensed wildlife rehabilitator.
If, on the first transplant attempt, no parents were to continue caring for their nestlings at the transplant site, and if these parents were to abandon their nestlings even after the housing was moved back to the original site 12 hours later, all other transplant attempts would be aborted. To repeat, if the first transplant attempt were to fail, and the parents did not resume care of the nestlings after the nests were returned to the original colony site, all remaining transplant attempts would be cancelled.
6) In case of a partial success, where only some of the transferred pairs attend their nestlings at the transplant site, the nests/nestlings of the non-attending pairs will be returned to the donor site in their original gourd (or the corresponding compartment of an identical house). As stated above, if the parents still fail to attend the nestlings after they have been returned to the donor site, the nestlings will either be fostered into active Purple Martin nests, or taken to one of the following licensed wildlife rehabilitators listed below. It should be noted that fostering nestlings into existing active martin nests is preferred over rehabilitation, since nesting parents cannot recognize their own young and readily adopt fostered-in nestlings. (Brown, 1997) The additional burden imposed on foster-parents by the extra nestling(s) is compensated for by the fact that the breeding pairs used as foster parents are trained to accept supplemental feedings in the form of crickets, mealworms, or egg. While this feeding technique was developed primarily to aid in survival of adults during periods of poor spring weather, it was discovered that breeding martins would also feed their nestlings the supplemental food during poor weather. (Kostka, 2006) Purple martins nestlings were successfully fostered into nests in 2004 with a 100% fledge rate. Rehabilitation will only be used as a last resort since Purple Martins are more successfully raised by foster-parents.
7) If transplanted pairs attend nestlings as expected, all nestlings will be banded, periodically weighed, and monitored every other day until at least one week after fledging to insure that they are being fed regularly and sufficiently by parents. Any nestlings not receiving proper parental care will be fostered into active Purple Martin nests as described above. Any fledglings not receiving proper parental care will be taken to a licensed wildlife rehabilitator. Supplemental feedings will be made available to parents. Assuming parents fledge nestlings successfully, transplant sites will be managed in the spring of 2008 and monitored for the return of transplanted parents and any offspring, which will be readily identifiable by way of individually numbered leg bands.
Wildbird Recovery, Middlesex, Beth McMaster, 724-898-1788.
Skye’s Spirit Rehabilitation and Education Center, Mary Jane Angelo, Harrisville, 814-786-9677.
Pennsylvania Wildlife Center, Verona. 412-793-6900.
Wildlife Works Inc., Youngwood, Westmoreland County, 724-925-6862.
Allen, R. W., and M. M. Nice. 1952. A study of the breeding biology of the Purple Martin (Progne subis). Am. Midl. Nat. 47: 606-665.
Baker, R.R. 1984. Bird Navigation: The Solution of a Mystery. London: Hodder and Stoughton.
Berger, G. 2006. “Relocating [Purple] Martins”. Purple Martin Conservation Association Online Discussion Forum. http://www.purplemartin.org/forum/viewtopic.php?t=4279&highlight
Birds of Nova Scotia. Purple Martin. 2007. Nova Scotia Museum of Natural History. Website. http://museum.gov.ns.ca/mnh/nature/nsbirds/bns0254.htm
Brown, C. R. 1997. Purple Martin (Progne subis). In The Birds of North America, No. 287 (A. Poole and F. Gill, eds.). The Academy of Natural Sciences, Philadelphia, PA, and The American Ornithologists’ Union, Washington, D.C.
Brown. C. R. 1980. Sleeping Behavior of Purple Martins. Condor 82(2): 170-175.
Russell, K.R. and S.A. Gauthreaux, Jr. 1999. Spatial and temporal dynamics of a Purple Martin pre-migratory roost. Wilson Bulletin 111:354-362.
Hill, J. R., III, 1988. How to Attract Purple Martins. Purple Martin Update 1(1): 1-3.
Hill, J.R., III, 1994. The growth of nestling Purple Martins. Purple Martin Update 5(3): 1-9
Hill, J.R. III, 1997. Sex/Age Differences in the Breeding Success and Mate Choice of Purple Martins. Purple Martin Update 7(3): 28-29.
Holland, R. 2003. The role of avian landmarks in the avian familiar area map. J. Exp. Biol.. 206, 1773-1778.
Jacobs, J. Warren. 1909. “The Purple Martin and Houses for Its Summer Home” Gleanings No. 5. p. 36-39
Kale, H.W. II, 1964. Nesting of Purple Martins Aboard a Ship. Wilson Bulletin 76(1):62-67.
Kostka, K. 2000. Social attraction: A new technique for establishing a Purple Martin colony site. Purple Martin Update 9(3): 26-29.
Kostka, K. 2000. Cricket tossing: A new emergency feeding technique for Purple Martins. Purple Martin Update 9(4): 26-28
Kostka, K. 2005. The Mysterious Appearance of 30 Purple Martins at an Unused Martin House. Purple Martin Preservation Alliance website.
Kostka, K. 2005. Cross-species Fostering: An Attempt to Establish a Purple Martin colony by using Tree Swallows. Purple Martin Preservation Alliance website.
Kostka, K. 2005. Emergency Cold Weather Feeding in the Spring of 2005. Purple Martin Preservation Alliance website.
Kostka, K 2005. Purple Martins Breed in Natrona, PA, in 2005, as a result of Forced Dispersal Project. Purple Martin Preservation Alliance website. http://www.purple-martin.org/MartinsBreedinNatrona.htm
Kostka, K. 2006. Emergency and Supplemental Feeding of Purple Martins in Spring 2006. Purple Martin Preservation Alliance Website.
Jones, L. 1899. Martins Removed to the Zoo. Wilson Bulletin. 11(5): 74-75.
Palmateer, C. 1995. Martins Ahoy! Martins Nest Aboard Canadian Destroyer. Purple Martin Update. 6(1): 29-30.
Peek, F., E. Franks, and D. Case. 1972. Recognition of Nest, Eggs, Nest Site, and Young in Female Red-Winged Blackbirds. The Wilson Bulletin. 84(3): 243-249.
Plewes, J. 1990. Building Birdhouses for North American Birds. Veritas Tools, Pub., Ottawa, Ontario. p. 5.
Sauer, J. R., J. E. Hines, and J. Fallon. 2005. The North American Breeding Bird Survey, Results and Analysis 1966 – 2005. Version 6.2.2006. USGS Patuxent Wildlife Research Center, Laurel, MD
Todd, Clyde, W.E. Birds of Western Pennsylvania. 1940. University of Pittsburgh Press. pp 375-378.
Wallraff, H.G., Chappell, J.M. and Guilford, T.C. 1999. The role of the sun and landmarks in pigeon homing. J. Exp. Biol.. 202, 2121-2126.
Winkler, D.W. and J. P. McCarty. 1990. Method for Transplanting Nests of Barn Swallows. Journal of Field Ornithology. 61(4): 426-430.
Appendix A: Background of Conservation Efforts in Southwestern PA
For the past eight years, from 1999-2006, the Purple Martin Preservation Alliance (PMPA), in cooperation various agencies and individuals, has attempted to establish Purple Martin colonies at multiple sites in Southwestern Pennsylvania, an area of martin scarcity. These efforts include the placement and ongoing management of Purple Martin housing at the following locations: Lock & Dam #4 in Natrona, Allegheny Co, Lock & Dam #5 in Freeport, Armstrong Co., Lock & Dam #6 in Clinton, Armstrong Co., and Crooked Creek State Park, Ford City, Armstrong Co., Vandergrift Golf Course, Vandergrift, Beaver Run Reservoir, Export, as well as residences at Apollo, Slickville, Alverton, and Natrona Heights. Most of these locations are ideal Purple Martin habitat – open areas on waterfront property (Hill, 1988).
This Purple Martin housing consists of wooden and metal multi-compartmented houses, as well as plastic and natural gourds. All housing is easily accessible and designed to allow for monitoring and management of nest contents, and is kept free of non-native nest-site competitors. House Sparrows (Passer domesticus) and European Starlings (Sturnus vulgaris) are controlled by way of trapping or nest removal. Starlings are also excluded with starling-resistant or starling-proof entrance holes.
To further enhance the chances of attracting martins, the Social Attraction technique (Kostka, 2000) has also been utilized. Decoys have been deployed and martin vocalizations broadcast over outdoor loudspeakers in an attempt to create the illusion that these sites are already colonized, making them more attractive to investigating martins. The broadcast martin vocalizations also act as a beacon, advertising the sites to migrating or cavity-hunting Purple Martins. Artificial nests and mirrors have also been employed to enhance the illusion of colony site activity.
Appendix B: Current Status of Purple Martins in Southwestern Pennsylvania
Purple Martins are scarce in southwestern Pennsylvania, especially along the Allegheny River corridor, with very few or no Purple Martins spotted during breeding bird surveys over the past seven years. (Sauer et al. 2006) According to the Breeding Bird Survey, Purple Martins were counted on only 2 of the 24 routes within a 40 mile radius of the project area in the years 1999-2005. A total of only 8 Purple Martins were seen on these 24 routes over a period of seven years between 1999 and 2005. While several colony sites exist in this area, these BBS numbers attest to the general scarcity of these swallows in southwestern Pennsylvania.
Each survey route is 24.5 mi long, and consists of 50, three minute roadside counts along the length of the route. (Sauer et al. 2005) Since Purple Martins are birds of open areas near human habitation, which are near roads, one would expect that they would be one of the more visible species on survey routes. According to the Purple Martin Summer Distribution Map (Sauer et al. 2005), which predicts the average number of Purple Martins that could be seen in about 2.5 hours of birdwatching along roadsides by very good birders, the number of Purple Martins predicted was “one or less” for the proposed project area. Furthermore, according to the Purple Martin BBS Trend Map, 1966–1996, Purple Martin numbers have undergone a long-term significant decrease in the proposed project area. (Sauer, et al. 2005).
Appendix C: History of Purple Martins in Southwestern Pennsylvania
The scarcity of Purple Martins in southwestern Pennsylvania is largely a result of three factors: the martin-killing weather of Tropical Storm Agnes in June of 1972, the continued depredations of the non-native European Starling and House Sparrow, and the lack of interest in the hobby from an increasingly urbanized culture. Tropical Storm Agnes stalled over western Pennsylvania in late June of 1972, at the peak of the Purple Martin breeding season, causing 6-10 inches of rain to fall on the region from 20-25 June. Since Purple Martins rely exclusively on flying insects for food, and since the continuous rains depleted the air of flying insects, almost all of the Purple Martins in southwestern PA died of starvation, along with their nestlings, during these prolonged rains. Normally, Purple Martins populations would recover naturally by attracting individuals from outside the devastated area in successive breeding seasons. However, in the martins’ absence, the aggressive European Starlings and House Sparrows became entrenched in the unoccupied housing, and in many cases prevented the gradual re-colonization of former sites. Purple Martins are usually timid when investigating new sites, and are usually repulsed by these non-native species once they have claimed the housing. Finally, after the widespread die-off, many martin “landlords” gave up the hobby and did not pass on the tradition of offering martin housing to younger generations, resulting in a decades-long lack of properly managed housing.
Information gleaned from numerous conversations with long-time residents of the project area, individuals who either managed Purple Martin colony sites or were Purple Martin enthusiasts, suggests that Purple Martins were once fairly common in the project area and throughout southwestern Pennsylvania. The author’s personal conversations with Gerald Presley (deceased), who resided in Brackenridge, Allegheny Co., adjacent to Natrona, related accounts of numerous colony sites in the immediate area. The author spoke to two of the founders of these colonies prior to their deaths. There were at least seven active colonies in the Natrona Heights, Brackenridge, and Tarentum area alone, from approximately 1940-1960. (Presley, pers. comm.)
Duke Snyder, the manager of a colony in Butler, PA, has, through local research, determined that there were at least eight colonies within a two mile radius of Butler, Butler Co., PA in 1966. (Snyder, pers. comm.) Roy Bauder, a landlord in Portersville, Butler Co., PA, counted at least 15 colonies in the Portersville, Butler Co., PA area in the 1950’s. (Bauder, pers. comm.) Lloyd Getty (deceased) of Saxonburg, PA spoke of numerous colonies in Saxonburg, Butler Co., PA, (Getty, pers. comm.) C.W. Parker recorded at least nine colonies in Allegheny in 1925. (Todd, 1940) Presently, there are only three colonies in Allegheny Co., PA.
The Purple Martins’ social nature adds to the difficulty of establishing new colonies in areas where establishment is already difficult because of the scarcity of Purple Martins. Martins prefer to nest in the company of other martins and usually choose to reside at established sites rather than nest alone at new, untested sites. Subadult females, who must often accept subadult males as mates, usually prefer already established breeding sites, because they have access to extra-pair copulations with genetically superior adult males (Morton, 1990). These factors help to explain why no new colonies have been established in a multi-county area of southwestern PA, despite concerted efforts to attract them.