­ PIBO Migration Summary


April 24th – April 30th, 2012





A mixture of rain, cool temperatures, and strong north winds made for a relatively quiet week, although conditions improved towards the end of the summary period. Diversity at the station, for example, ranged from thirty-one species on April 26th to forty-seven species on the 29th during our official count period, compared to a Daily Total (DT) of 71 species recorded last year on April 26th. Just one new arrival for the spring was recorded from the 24th to the 28th – a Northern Rough-winged Swallow.


Despite the less than ideal conditions, migrants continued to make their way north in small numbers and a variety of species were noted daily throughout the week including White-throated Sparrow, Yellow-rumped Warbler, Hermit Thrush, Blue-headed Vireo, and Eastern Towhee, among others. Nine warbler species were tallied from the 24th – 30th including spring ‘firsts’ for Black-and-white, Nashville, Yellow, Common Yellowthroat, and Northern Waterthrush. Swallows were active from the 27th – 29th, with 75 Barn Swallows noted on census on the 27th, and five species recorded on April 29th.


The banding effort this week was generally unproductive, although a few birds were captured in ones-and-twos including Blue Jay, House Wren, Ruby-crowned Kinglet, Yellow-rumped and Black-and-white Warbler. April 29th saw an increase in activity, with 47 species recorded during the official morning ‘count’ at Fish Point, along with a Whip-poor-will and Northern Mockingbird observed near the PIBOcottage in the late afternoon. The last day of the month was extremely wet, yet a nice variety of migrants were observed, including six warbler species, lots of swallows, and a Willet.          


PIBO’s next summary will be posted on May 9th.


Photo: Sumiko Onishi