05-21-15 Bird Field Note

05-21-15 Bird Field Note

May 21, 2015

Debbie Leick compiled this week's bird field note. The note describes Common Poorwills, raptor migration, osprey telemetry, and raptor breeding.

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Two runaway mules from a neighboring property visited this week. Their owner enticed them back home with a feedbag of grain.

Poorwills have a huge wingspan for a bird that weighs less than a robin. Males have bright white tail tips, like those seen here.

Common Poorwills exhibit several interesting features, such as a mouth structure adapted to swallowing insects and a combed middle toe. The function of their toe structure is unknown.

The poorwills were generally calm during processing, though they sometimes hissed at us.

Most poorwill roosts we documented were on the ground near the base of a shrub. After a rainstorm, Mat found one roosting a few feet off the ground in a deciduous shrub

This poorwill roosted just off of Whaley Draw road. Two poorwills tracked in this area appear to be roosting near females, suggesting that they are close to nest initiation. Mat found one potential nest scrape and roosts that show signs of repeated use.

We concluded our spring count this week, with a season total of 1,317 migrating raptors, compared to 1,097 in 2014, and 2,237 in 2013. In general, species totals were similar to 2014, with the exception of more Cooper’s Hawks, Red-tailed Hawks and larger-sized falcons counted this year, but fewer Golden Eagles and American Kestrels.

A Tree Swallow momentarily perched at the count site.

Rapunzel’s nomadic behavior from last summe r seems to have resumed this spring. Since arriving in Montana from her Texas wintering grounds at the end of April, she hasn’t remained still for more than a couple of days. So far, her journey has been confined to Western Montana, including two stops near MPG Ranch. Currently, she is near Philipsburg,

As spring migration comes to a close, most of the raptors that breed here have returned to their territories. These week-old chicks in Lower Woodchuck were the first Red-tailed Hawks to hatch on the ranch. This year we will begin tracking Red-tailed Hawks to learn how their territories relate to each other, where they spend winters, and which migratory routes they use.

American Kestrels began arriving in early April, but only recently settled into their territories to lay eggs. So far, we detected pairs of American Kestrels at the 12 territories marked with yellow pins on this map. We documented eggs at the four circled territories.

We reencountered six American Kestrels banded in previous seasons. We banded this adult male (top right) in the summer of 2012. Since then, we have documented his nesting efforts in each successive breeding season.

We hope to put these GPS units on 15 American Kestrels this summer. Because this is our first time tracking the species, we will closely monitor AK-62 over the next two weeks before outfitting other individuals.

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