Super Purple Martin Colonies
From: Steve Kroenke, Tallahassee, Florida
Date: 12/4/99
Time: 11:22:42 AM
Comments
They are big. They can be monopolies. They are a tremendous responsibility. They are source of pride and joy to their human hosts. And they can be heart breaking tragedies. What are these paradoxical phenomenons that can bring both happiness and sorrow? They are super purple martin colonies (SPMC); colonies of 70, 80, even 100 pairs or more. Colonies where martins literally cover the skies and bring great smiles to their human landlords and to "others" which are sure to be watching and waiting. These "others" have entirely different intentions.
I managed two SPMCs, a mini SPMC of 80 pairs and a mega SPMC of 150+ pairs. Though for a period of time I enjoyed the distinction of hosting a SPMC, I will NEVER again strive to attain that lofty status. Neither one of these colonies is in existence today.
There is more to managing a martin colony than just "quantity"; the "quality" of your martin experience is far more important and enjoyable. I tried to have both and was successful for a period of time. But hosting a SPMC can truly test your ability to balance quantity and quality issues.
First, managing a SPMC takes a lot of time if you take your role as a purple martin landlord seriously. It truly takes a dedicated person to assume that role and maintain the energy to continue through the entire purple martin nesting season and persist year after year. Think about all the monitoring, maintenance, and protecting. You just can't sit back and relax; it requires a lot of work. You become the Chief Executive Officer, Security Guard, Maintenance Man, Record Keeper, and Day Care Attendant--a Jack of All Trades. And you may be doing this for 100 pairs of nesting martins in a SPMC.
I always manage my colonies with a "purple passion" by making detailed observations, keeping good records, protecting the martins the best I could, and ensuring their houses/gourds were in good shape. I strived to raise as many martins as possible and actually considered them as "family" in some ways. Doing this with over 100 nesting pairs was sometimes overwhelming and consumed a large amount of my time. Also, having so many nesting pairs increased my "worry factor" and I often got quite emotionally involved in managing the colony, particularly when the colony was under some kind of stress. Plus, the up keep on "hundreds" of gourds/house compartments can be quite trying at times. Worrying over 100+ pairs of martins was more than just trying at times.
Second, SPMCs can function as "biological sponges" and soak up all available martins in an area. This is particularly true in regions where martins are not that abundant or are undergoing population declines; areas of super martin abundance can host multiple SPMCs. Martins are attracted to established sites and particularly to sites that offer an abundance of nesting possibilities and already have martins in residence. The SPMCs are like magnets and pull in the sub adult martins (SY) martins which are looking for territory. This effect may preclude many first time potential landlords from even attracting martins to their sites. So SPMC landlords may be unintentionally depriving other folks of a chance to host purple martins. Many of the SY birds, which typically colonize new sites, are trying to find nests at the local SPMC.
When I managed my two SPMCs, I always had large numbers of SY males trying to set up territory. Many were successful because of the multitude of houses/gourds, but many were not and those unsuccessful SY males just stayed around the colony site for weeks. They constantly "bothered" established pairs and harassed young martins in the nests and those that had recently fledged.
Third, your SPMC may be a jewel in your eyes, but may be an eyesore to your neighbors. Though I never personally experienced "neighbor backlash" because I lived way out in the country, I have talked with some neighbors of a local SPMC landlord who lives about 4 miles from me. Several spoke negatively of the colony and complained of "too many" birds flying around. Others said the birds "pooped" on everything around the area. Just look at my car said one neighbor! One was even afraid the SPMC landlord was going to shoot his pet cat if the cat bothered the martins. You may get an "eccentric" label by your neighbors with hundreds of purple martins nesting in your yard, though such a label would not bother me.
By far, the greatest problem that I experienced with SPMCs was predation. The number one "law of the jungle" is: Large concentrations of prey attract predators. Simple as that. It makes no difference if it is antelope in Africa, seals along the coast of California, or purple martins in your backyard. When there is so much available food around, then predators will naturally try to take advantage of the situation. And the more food that is available, then there will be more predators on the prowl. SPMCs may become super feeding stations for all kinds of predators.
But there is an important difference with purple martins that makes them far more susceptible to predation than many other prey species. Martins now nest in concentrated colonies in very restrictive environments where predators can destroy the entire colony in a short time. A martin house or gourd cluster full of adult and baby martins is a tempting and easy target for predators. Rat snakes will climb unprotected poles and devour the martins. A single predator, such as a raccoon or large owl, can cause incredible destruction to nesting martins in just a few nights. Barred owls inflicted terrible death and destruction on both my SPMCs, literally destroying both colonies over a period of time. Accipiter hawks, like sharp-shinned and Cooper's, will stake out these large colonies and raid them daily. One of my SPMCs was under siege by hawks from February, at the beginning of the martin season, to July, when the martins finally left. Cooper's hawks took large numbers of recently fledged young.
Though we can install pole guards to virtually eliminate most terrestrial predation by raccoons and rat snakes, the winged predators are the most difficult to deter. Owl guards on houses/gourds will certainly help, but are not a sure thing, and attacks by Accipiter hawks and falcons in the air will continue.
The bottom line is that SPMCs are an open invitation to all predators in the area to come to the feast. Remember: the chances are very good that an owl, Accipiter hawk, rat snake or raccoon will eventually find your SPMC. These predators are everywhere and many are quite common.
So what is a manageable number of purple martins? Is there a magic number that will both sustain your colony while reducing the management time and minimizing incidents of predation? I certainly don't know that elusive number. It all depends on your ability/desire to effectively manage your colony, your location, and the abundance of martins in your area. A colony between 20 and 40 nesting pairs of martins seems reasonable to me. You can enjoy your birds, easily manage the several gourd clusters or houses you have erected, and hopefully reduce the incidents of predation. However, "reasonable" colony size will NOT "immunize" your martins against predation, but may reduce the chances.
And a few comments from the heart...
I must confess that I sincerely enjoyed hosting a SPMC for the most part and do miss it in some ways. I enjoyed watching the hundreds of martins swarming around their nests, the hundreds of babies clamoring for food, keeping detailed records, and making careful observations of martin behavior. But I never could objectively accept the intense predation that my two SPMCs endured. I simply could not view my SPMCs as "biological study areas" and calmly watch martins hunted by hawks and owls. I never could equate a martin being caught by a hawk as equal to a martin catching a dragon fly even though in the "web of life", it really is the same thing. I guess most martin landlords have that emotional connection with "their" birds and that is both a good and not so good thing. We just need to try to find that elusive balance between objectivity and emotionalism in managing our martin colonies. I'm still trying to find it and maybe some day I will.
Steve
