This season brought a number of challenges for the birds, including feather mites, unusual weather, and predators. A sudden cold spell in May seemed to be one main reason for nest failure. Still, 832 birds fledged from the nest boxes this year. As usual, most of these were tree swallows (386), followed by western bluebirds (254), then house wrens coming in third (152). White-breasted nuthatches had more success this year than usual, with 15 fledglings making it out of their nests. The ash-throated flycatchers also had more fledglings than usual (25), breaking the downward trend they had been experiencing in recent years.
Our Winters Park site, where we brought back nestboxes after a hiatus of several years, proved to have at least four previously-banded tree swallows using the nestboxes this year. For some reason, the north side of the creek was much more popular there than the south side, and the only occupants were tree swallows and ash-throated flycatchers.
The Davis Nestbox Network, a completely new site, had just a few active nests as expected for its first year, but they were quite successful and had several second clutches.
We’ll be planning a few changes to the sites over fall and winter. Moving some boxes may help against predators, and we’ll be adding a few more boxes to our smaller sites.