Wednesday, May 14, 2008

Cavity Nesting News

Good and bad news in the cavity nesting world: The bad news is that I came home from Magee Marsh to find a starling had built a nest in a Super Gourd, a plastic gourd designed for Purple Martins. This one was hung low on a shepherd's crook for the Tree Swallows, not high on the raised rack for the martins.

Starlings just can't resist the big round entry hole and roomy interiors of these gourds, although in retrospect, I'm glad she picked this empty gourd, and not one that the martins are using. She had filled it to bursting with fresh and dried grasses in 2 or 3 days.

This is probably the same bird that I just evicted (twice) from a modified apartment in the aluminum house, one where I had taken out a dividing wall to create a 6" x 12" room instead of the standard 6" cube. Again, the round hole and larger space is very attractive to starlings. After the second eviction, when I also removed an egg, I changed the front doors from 2.5" round holes to the starling resistant crescents I have in my natural gourds, and Ms. Starling couldn't get in to finish her clutch.

I suspect that's why the rush to move into the gourd; she had eggs to lay. I tossed one out the day I got back. Here's another one:

And here it is in my hand and close-up:
Martineers debate over the best way to house their birds. Round holes are easier for martins to negotiate, and are more familiar, so many people are reluctant to try starling-resistant entry holes (SREH.) Bigger rooms allows for bigger clutches, but attract starlings, which not only compete with martins for space, but which will break eggs, kill nestlings, and even kill adults, if possible. Right after the second eviction, when a martin couple was checking out the aluminum house with the SREH, I watched a starling attack the male martin as it was wriggling its way out of the compartment. Just as I was about to charge outside and scare off the starling, other martins saved the day and the male flew off unharmed.

Based on my (limited) experience, I am a believer in larger rooms or gourds and SREH. I do have 5 round holed gourds, four hung for the martins to give them a choice, and this one, which has now become a trap box for starlings. This particular bird won't need any more eviction notices.

In the Good News department, the Tree Swallows are laying their eggs, using a wooden nest box that had been my sparrow trap box.

Day One was Monday,
when this little pearl surprised me. I didn't even think the nest was complete, but I guess Mother knows best when it comes to egg-laying.

Today, I walked up to the nest box to do a morning check, and followed all the same steps I do with my bluebirds. I give a low whistle, to warn Mama that I am approaching the box, at which point she usually flies out. I then tap on the side of the box before I open it, in case she didn't hear me. I did all that with the Tree Swallow box this morning, and when I opened it up, she was sitting tight and wouldn't move. I closed the box up and checked it this evening:


Edit: Update 5/15 - second bluebird nest is underway as of today.

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