The Perks and Perils of Nesting

April is drawing to a close, which means that, here in the southeastern U.S., most of the summer-resident birds have arrived on their breeding territories.  They join the year-round resident species—including phoebes, cardinals, Carolina Wrens, and bluebirds—that have possibly already nested this season, and could be starting on second broods.  Several of these common, resident birds spend a lot of time around human habitation, so if you live in this region of the country, you may have noticed nesting behavior from some of them during the last couple of months.  The ones that typically build around my home are Carolina Wrens and Eastern Phoebes, which I see in the yard almost every day.  In the spring and summer, the Carolina Wrens will often build their small, domed nests in the garage or in the chairs or potted plants on the patio.  This April, they built a nest on top of some random stuff in the garage.  As you can see, they used grasses, oak blossoms, mosses, leaves, and string in the outer layer.  There are several enormous post oak and red oak trees in the yard, so oak blossoms were all over the place earlier this season, and I have to say that I was getting sick of tracking them into the house.  Good thing that the wrens were able to repurpose them.

Carolina Wren eggs

Finer grasses and various bits of fuzz—feathers and possibly fur—lined the nest, and, as the photo shows, the female wren laid five eggs.  This is normal for Carolina Wrens, which lay anywhere from three to seven.  The female wren incubated the eggs for several days.

Incubating

Wrens build nests around the house every year, and, apart from peeking into the nests every now and then during the roughly month-long process from incubation to fledging, I never really do anything that could disturb them.  For one thing, it’s technically illegal to disturb or damage the eggs and young of wild birds, and for another, I figure that interfering with nature is usually unwarranted.  The main exception I will make is for species that are endangered, or just generally imperiled.  Carolina Wrens, though?  Thankfully, they seem to be doing just fine.

The empty nest

The species is doing just fine, that is.  Unfortunately, these particular individuals had their nest raided by some sort of predator before the eggs could hatch.  Maybe a snake?  Several nonvenomous species, including gray ratsnakes, black racers, and speckled kingsnakes, are pretty common in this area.  I do not endorse killing snakes, by the way; they have a right to be here, and the benefits that they provide (e.g., rodent control) far outweigh any damage that they occasionally do to the birds that people love to watch.  Below is a picture I took a couple of years ago of a large gray ratsnake that had taken up residence in the garage.  A raccoon is another possibility; although I haven’t yet seen raccoons near the house itself, I know that they hang out in the woods at the creek.

Gray ratsnake

The Carolina Wrens have not re-nested in the garage, but, given the fact that a pair of wrens can have up to three broods a year, I suspect that they do have another nest somewhere close.  Hopefully, the second brood will fare better.  

On a lighter note, even though the wrens had a failed nest this spring, the Eastern Phoebes successfully raised at least three young over the garage entrance.  Phoebes typically don’t build low to the ground, so unless you bring out a ladder, you’re probably going to have a hard time looking into their nests.  Until they hatch and the young birds are large enough to stick their heads over the edge, I usually have no idea how many eggs there were.  The brood sizes of phoebes can vary fairly widely—from two to six.  Like Carolina Wrens, phoebes easily acclimate to human activity; as long as you leave them alone, they will nest year after year in the same spot on a ledge, over a porch, or under an eave or a bridge.  

The phoebes' nest

The phoebe nestlings in the garage nest grew rapidly, and eventually the concrete below became coated with bird droppings—yuck.  I expected the birds to fledge a day or two before they finally did; they had been looking very large and mature, but I guess that they weren’t finished developing yet.  On the day that they did wind up leaving, I was standing at one side of the garage entrance and peering at them through my binoculars.  My presence apparently agitated them, because they all blasted out of the nest at once and flew strongly to the row of hardwood trees lining the driveway.  Clearly, they were ready!  Maybe the adult phoebes will start another brood, or maybe not.  They can have up to two per year.  For many of the other bird species on this property, however, the season is just getting started.

Phoebe nestlings