Questions & Answers with James
R. Hill, III
(by Kent Justus)
Dear Forum Readers:
For those that have never seen the following question and answer series, I have
reposted it for your benefit. James R. Hill, III is the founder and Executive
Director of the nation's foremost Purple Martin organization, the PMCA ( Purple
Martin Conservation Association ). Jamie was kind enough to
answer the following 26 questions exclusively for The Purple Martin Forum readers.
This is an article that you will want to print and keep. Enjoy...
1. What is your educational background and how did you become interested in Purple Martins? In 1975, I earned a Bachelor of Science degree in Biology at the Edinboro University of Pennsylvania, which is located in my hometown. During my last year there, I happened to take a course in Ornithology. The experience was such an epiphany for me, that I knew I had to devote the rest of my life to birds. To further my education, I went on to graduate school at Penn State University where, in 1982, I earned a Masters of Science degree in Ecology, with a minor in Wildlife Management. The title of my Master's thesis was "Nest Reuse in the Barn Swallow," and I conducted my field research at 35 different farms. While in the library researching the life history of the Barn Swallow, I read everything I could on the other North American swallows, including the Purple Martin. This is how I became interested and reacquainted with the martin. I say reacquainted, because, when I was a child, the summer camp across the street from my home had a thriving colony of martins in two wooden houses atop large metal poles. I remember sneaking across the street and shaking those poles to make the birds explode out of their houses in terror. I did this to be mischievous and to impress my young friends. I really enjoyed the thrill of those stealthy raids, especially the strong reaction I was able to evoke in those mysterious birds. As a result, I shook those poles a lot. In hindsight, I guess I've never really grown up. I'm still "shaking" martin poles, only today I'm not sneaky about it and do it in the name of science and animal husbandry. Now instead of being called a "prank," I've given it a more respectable name; it's now called "doing a nest check." Obviously, old habits die hard.
2. What caused you to go from having a casual interest in Purple Martins to feeling the need to form the nation's foremost martin organization, the Purple Martin Conservation Association (PMCA)? I'm frequently asked, "WHY ON EARTH DID YOU DO IT?" "Why did you give up a lucrative job, sell most of your earthly possessions, and start a nonprofit conservation organization just to help some purple bird?" The answer is, because I had to. The research I was conducting at the time revealed that the Purple Martin needed help, BIG HELP. Several things were conspiring against it. The just-published North American Breeding Bird Survey showed that the Purple Martin population was undergoing long-term declines over vast areas of its breeding range, while at the same time, large numbers were reported dying of unknown causes on their Brazilian wintering grounds. I also recognized that the human cultural tradition of putting up housing for martins was dying out as society became more urban and less rural. Worse yet, most people who were putting up housing for martins weren't doing it correctly or successfully. Instead of attracting martins, their houses were just fledging nonnative House Sparrows and European Starlings, the martins' worst nest-site competitors. In other words, despite their good intentions, most people erecting martin housing were doing more harm to the species than good. The final motivation for me to do something was the lack of reliable information. The bulk of the information available to martin landlords was that being disseminated by martin house manufacturers. These folks had no training in biology, rarely consulted the scientific literature, and often promoted the martin using myths, biases, and propaganda! Landlords were drowning in a sea of misinformation. Obviously, there was an urgent need for a scientifically-based conservation organization to help the Purple Martin and to educate martin landlords. So I formed one.
3. When was the PMCA formed and what is its current membership? In January of 1987, the PMCA was officially incorporated as a non-profit, tax-exempt charity, affiliated with Edinboro University of Pennsylvania. Eleven years later, our membership stands at 6,500, although over the years we've had 16,000 different martin enthusiasts as members. Pretty amazing considering this is an organization devoted entirely to just one species of bird.
4. How does the PMCA differ from other martin organizations? Among martin organizations, the PMCA is the only one based at a university, the only one that publishes a color periodical devoted entirely to matins, the only one that conducts scientific research on martins, the only one that awards grants to other martin researchers, and the only one that has an ornithologist and photographer on staff specializing in Purple Martins. The quality of our publication and research speaks for itself.
5. What types of research are funded by PMCA membership dues? The PMCA conducts research on the martin's North American breeding grounds, on its South American wintering grounds, and along its middle American migration pathways. We have three continent-wide, cooperative research projects that our members participate in: the Colony Registration Program, the Scott-arrival Survey, and Project Martinwatch. We also award 1-3 annual PMCA Research and Conservation Grants to university graduate students (or exceptional martin enthusiasts) for research on martins, or for serious conservation projects. To date, 6 different individuals have been awarded grants. At PMCA headquarters, I have been conducting research on martins since 1981 (18 years). I've looked at nest reuse, parasite control, cavity-depth preference, cavity-size preference, entrance hole-size preference, hole-shape preference, migration timing, nestling growth, porch wandering, premature fledging, nest changing, owl predation, mate fidelity, site fidelity, natal dispersal, grit ingestion, clutch size, molt, clutch-initiation dates, management strategies, nest-checking regimes, and post-reproductive roost use.
6. What are some of the research projects that are currently benefiting from PMCA funding? Besides all the research mentioned above that the PMCA conducts using moneys generated from memberships and product sales, our most recent grant recipient, Chris Grainer, a graduate student at Clarion University in Pennsylvania, is studying the affects of intensive agrochemical use in grape vineyards on the behavior and reproductive success of Purple Martins. This research is particularly pertinent in that more and more of our rural lands (where a high percentage of martins breed) are becoming agricultural monocultures, heavily dependent on pesticides, herbicides, and fungicides.
7. What do you feel is the single most important reason why people fail to attract nesting martins? There is no single reason. People fail to attract martins because they make a whole assortment of mistakes. Many people buy inadequate housing, place it poorly, open it at the wrong time, don't control nest-site competitors, and don't know how to identify a martin should they attract one.
8. Do you recommend playing the "Dawnsong" tape for those that are having an especially difficult time in establishing a colony? Absolutely! Relying on a martin's eyesight alone (especially when they migrate at night coming north) to help them find your newly-placed martin housing is not a very efficient way to "advertise" available nesting sites. The scientific way is the martin's way. Adult martins use dawnsong (an early-morning vocalization given in flight that covers up to 100 cubic miles of air volume) to advertise available cavities to migrating subadults, the age group that typically colonizes new sites. Playing the Purple Martin dawnsong tape or CD (an actual, digital recording of Purple Martin dawnsong) is the very best way to attract martins to a new site. It really works!
9. Most manufactured aluminum martin houses on the market today have very small, 6"x6" compartments. Do you recommend placing owl guards on these houses even before you have attracted martins to them? No. Wait until you've attracted martins and they've laid eggs, then install the owl guards. (Owls usually don't attack until there are nestlings in the houses.) For about 15 minutes after installation, the martins will be hesitant to enter their compartments, but will soon acclimate. Install the guards during warm weather and only at mid-day. Why wait? Because an owl guard on the outside of a martin house makes it less attractive to cavity-hunting martins looking to colonize a new site. Once you've attracted a breeding group of martins, you can leave the owl guards on permanently, from year to year, since the same breeding martins will return year after year.
10. Based on your years of research, what compartment size are martins most likely to choose for their nest when given the choice? We've done extensive testing (as have several other martin researchers) on cavity-size preference in breeding Purple Martins. Martins were given a choice between an equal number of 6"x6" compartments and 6"x12" compartments. Overwhelmingly, martins chose the larger compartments in which to nest. This is not surprising considering that a martin is 7&1/2" long. Like most other cavity-nesting birds, martins show a strong preference for the largest cavities they can find. Martins lay significantly larger clutches of eggs in larger cavities, too. If you are building a wooden house, I suggest a cavity of 7"x12". Better yet, hang up several 8-12" gourds - they have the largest cavities of all. But since starlings also like larger cavities, be prepared to deal with them through trapping and shooting, use of gourds rather than houses, and by using the starling-resistant hole on houses.
11. Entrance hole size - there are many different sizes used today ranging from 1-3/4" to 2-1/2" or larger. Referring specifically to round entrance holes, what size do you feel is ideal for martins and why? At the PMCA's research facility in Edinboro, PA, I conducted several years of research on hole-size preference in Purple Martins. I offered breeding martins an equal choice among 6 different entrance holes sizes: 1-3/4", 1-7/8", 2", 2-1/8", 2-1/4", and 2-3/4". They used all six of the different sizes, but showed a preference for 2-1/8". Each different entrance hole size has advantages and disadvantages, though. Smaller entrances offer more protection form predators, blowing rain, and cold wind. Whereas larger entrances offer more ventilation in hot weather and room for more than one nestling to tick its head out for food begging. A 2" hole is probably an ideal compromise choice. It's generally thought, however, that a 1-7/8" hole will exclude predatory Screech Owls. I would never recommend a hole larger than 2-1/4".
12. There are a couple "starling-resistant" entrance holes (SREH's) being touted these days. Can you give their dimensions and explain why they are beneficial to martins? There is a crescent-shaped hole and an oval hole. Both are 1-3/16: high and about 2-3/4" wide. The oval hole is cut using a 1-3/16" forstner bit. The PMCA's web site (http://www.purplemartin.org) shows dimensional diagrams of these holes. The holes are beneficial because they keep the introduced European Starling from nesting in houses intended for martins, yet allow martins to squeeze in and nest. This is a breakthrough since territorial starlings will aggressively defend an entire martin house, preventing colonization by martins at unestablished sites. If allowed to nest in houses that already have martins, starlings (which weigh 80 grams) routinely kill martins (which only weigh 50 grams) in beak-to-beak fights over cavity "ownership." Starlings have long, sharp bills, whereas martins have short, blunt bills. Such fights are grossly mismatched, sort of like a professional boxer taking on a scrawny high school fighter.
13. Would you recommend "starling-resistant" entrance holes (SREH's) on housing at colony sites that haven't yet attracted nesting martins? Yes, unless you have the time to stand guard at your martin house all day long, every day, with a pellet rifle to ward off the hoards of cavity-hunting starlings that will inevitably descend on it. True, in side-by-side preference tests, martins prefer normal, round entrance holes, but SREH's will ultimately increase a landlord's chances of attracting martins if they don't have the time to stand guard. These holes also save martins' lives since many are mortally injured in battles with starlings.
14. Houses or gourds? Do you have a personal preference? Gourds, gourds, gourds! Martins have the highest reproductive success in gourds relative to wooden and aluminum housing. Gourds are more predator resistant because they swing, martins lay larger clutches of eggs in them because they are roomier, and gourds are less attractive to House Sparrows and starlings.
15. Is there anything that can be done to make gourds safer from owl attacks? In our studies, Great Horned Owls found meals the easiest to get in commercial metal houses and the hardest to get in gourds. Despite this, we've had several reports of owls raiding martins in gourds. The only technique we've seen that completely eliminates owl predation in gourds is the building of a gigantic, winching, cage around an entire gourd rack. For better protection, use the largest gourds you can find, or hang some horizontally with the entrance at the tip of the neck.
16. What are the top five predators of Purple Martins range-wide? Great Horned Owls, Raccoons, Cooper's Hawks, Sharp-shinned Hawks, and Black rat snakes. Owl predation can be greatly reduced by placing owl guards on the houses; raccoon and snake problems completely eliminated by placing climbing animal barriers on martin poles; and hawk predation minimized by keeping the air space around your housing as open and free of trees as possible.
17. Have any predators been documented as preying on Purple Martins on their South American wintering grounds? Sure. I've seen feral cats patrolling the ground under Brazilian martin roosts and Accipiter hawks and falcons swooping through the hoards of martins coming and going form these same roosts. Large and small owls are also a problem in South America.
18. Parasite control - a touchy subject with some martin
enthusiasts. What would you tell people that refuse to believe that Sevin, Rotenone
or other chemicals will harm their martins? Read the scientific
literature! Martins eat the parasites in their nests and on their plumages.
Therefore, martins ingest the pesticides placed in their nests. These pesticides
have been shown to be harmful to birds. If you choose to conduct parasite control,
use a teaspoon of diatomaceous earth (DE) sprinkled around and under each nest,
or practice nest replacement. Some pesticides, such as Sevin, that the layman
feels are safe, may have sublethal effects, affecting birds negatively.
Note: Please read the PMCA's official stance
on DE prior to using it.
19. nest replacement is touted as the most "environmentally friendly" way to help control ectoparasites in martin nests; however, not all martin housing in use today raises and lowers vertically, nor does it open for easy access to the nesting compartments. In this case, what would you recommend for those landlords that want to control ectoparasites in the nests? DE sprinkled in each nest under the cedar or aspen shavings or pine needles you've placed in the compartments prior to martin arrival. As long as the nest stays dry, DE will scratch parasites to death. Add more DE if the nests become water soaked.
20. Some martin enthusiasts encourage the feeding of martins during harsh weather conditions. Mealworms, hamburger meat and hard-boiled eggs are some of the items that are used. What is your feeling on providing supplemental food to martins during harsh weather? There are two basic philosophies on this subject. Some people feel we should let nature take its course, after all, severe weather is a natural selective force shaping the fitness and evolution of martin populations. Only the strongest martins should live to pass on their genes. If we interfere, less fit individuals will live to pass on "inferior" genes. Other people believe we, as stewards of this human-dependent species, should perform every manipulation we can to help increase martin numbers since they have declined so dramatically during the past century. I am on the fence with this one. I can understand both viewpoints.
21. Some martin enthusiasts become so addicted to the hobby that their main goal each year is to attract more martins than the previous year until they have built up a "super colony" of over 100 pairs of martins. Do you think martin colonies can be too large? Yes. Large colonies become giant predator magnets. I know of no martin colony over 75 pairs that doesn't have hawk and owl problems. One site we know with over 300 pairs is hit repeatedly each day by aerial predators. With such high levels of predation, the breeding success of martins in such colonies is probably depressed. The level of aggressive fighting among martins is also greater in larger colonies, as is the spread of disease and parasites. Competition for food is also increased, forcing martins to fly farther from their housing to find food for their nestlings. This causes life-shortening stress on parents and increases the time between feedings for the nestlings, slowing their growth.
22. What do you feel is the "ideal" martin colony size that can be properly managed? The answer to this question depends on how much time the landlord has to devote to the hobby. A colony should only be as big as a landlord can properly manage. During the breeding season, a nest check of 100 nesting compartments can take about 30 minutes, if you move fast (as you should). This needs to be done every four days during the egg-laying period and every 5-7 days during the nestling period. A landlord should also walk underneath his housing once or twice each day to look for evidence of problems. Trapping and shooting House Sparrows and starlings is another factor determining how many cavities should be offered. No more than what the landlord can keep 100% starling and sparrow free. And don't forget annual maintenance. Housing needs to be taken down, nests cleaned out, housing washed off, repainted (if necessary), stored for the winter, and put back up in spring. Only build your colony to the size you can manage. For some people this is one 12-unit house. For others, it's several hundred gourds or a dozen multi-room houses.
23. What is the most surprising thing you've learned so far about martins over the course of your research? That they have elevated levels of reproductive success in gourds, relative to commercial aluminum houses, and that I haven't found a single mosquito in their diet despite three years of intensive diet sampling.
24. Do you feel the future is bright for the Purple Martin? The jury is out on this one. I'm concerned that in this modern society, with more and more humans growing up in urban settings isolated from nature, fewer and fewer people will be putting up housing for martins. This will be a disaster for this human-dependent species. I'm also very alarmed at how many landlords don't manage their sites, despite evidence showing that doing so can double the productivity of martins. And, finally, it's not encouraging when you see that the vast majority of the million or so martin houses in North America are in total neglect and house no martins. They're just functioning as highly-efficient starling- and sparrow-producing factories. But that's why the PMCA was founded. I believe we can all make the future brighter by all working to educate the public about Purple Martins.
25. You are considered the nation's premier Purple Martin authority by many. What are some of your personal goals in the martin interest over the next 5-10 years? I want to see our research in Brazil increase dramatically. I also want to see the number of members in the PMCA double or triple in size, allowing us to build a visitor center/museum/headquarters here in Edinboro, PA. I also want to produce a video or film on Purple Martins. And finally, I want to see participation in Project Martinwatch increase ten fold.
26. Is a book in the works? Yes.
