Friday, May 21, 2010

Purple Martin Colony Notes 2010

May, 10 2010

On or around the first of May I was outdoors and began hearing the mobbing calls of several species of birds. Looking towards my martin colony I spotted two Cooper’s hawks flying overhead, one with a bird in its talons. These are probably the same two hawks that have frequented this residential area for many years. Several male grackles, a blue jay and three purple martins banded together to mob the hawks, eventually driving them away. All this happened so quickly I was unable to identify the unfortunate bird that had been captured. It very well could’ve been a purple martin since it occurred over my colony. Moments before the incident I recall hearing their song overhead. It’s sad and not something a purple martin landlord wants to witness, but I guess everything’s gotta eat. I remember years ago watching a hawk snatch a European starling on the wing, and what an incredible sight that was. European starlings and English sparrows are not native to this country and both are vicious nest site competitors of purple martins as well as other songbirds. In my opinion (and I’m certain most martin landlords will agree) they can eat all of the European starlings and English sparrows they want. I normally do a nest check every 5-7 days, but I was busy and allowed 7 extra days to go by before checking again. On April 27th I had only 4 eggs and today I had a total of 81 eggs counted in 21 gourds. This confirms that so far I have 21 pair of purple martins, which is about average for my site. There are seven other gourds though that have nests in them, but no eggs, and I hope at least some of these will have eggs the next time I check.

A friend of mine recently established his own martin colony after several years of disappointment. It got to the point that he was about to give up, but I encouraged him to keep trying. It eventually paid off and he now has an established colony consisting of two pair. The only thing is he’s reluctant to manage it. He’s afraid that if he so much as talks near his housing they will leave and never return. This, of course, is totally untrue.

One of the main responsibilities is the conducting of weekly nest checks in order to prevent this. Purple martins will abandon a nest or entire colony if the wrong situations occur. These are listed the PMCA’s (Purple Martin Conservation Association) article entitled “Twelve Reasons Why People Lose Their Purple Martins”.

May 18, 2010

Today’s nest check presented not only an increase in egg numbers (94 eggs), but also 9 brand new nestlings.

I always tap on the pole that supports my gourd racks before I lower them just to let any incubating adults inside know that I’m present. No sense in surprising them. They’ll exit the gourds and along with the adults that were perched on the racks will fly to a nearby sweet gum tree or to a perch that I provide where they watch and wait for me to finish my landlord duties.

Today one lone female decided that she wasn’t going to leave her eggs. She eventually left the gourd, which enabled me to count her five glistening eggs.

By the way, the reason the egg’s shell begins to “shine” is due to the rotation of the eggs by the adults as they’re incubated so that they are warmed evenly. The eggs rub against the nesting material (leaves, pine straw, and small twigs) as they’re turned polishing them.

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