Tuesday, December 20, 2011

2011 songbird summary

Here's our songbird summary for 2011 (mostly written by research director Jay Carlisle)

During the 2011 autumn migration, we captured 5,196 birds of 52 species during 4,364.5 mist-net hours. This capture rate is slightly below average and the species richness is the lowest since 1999.

The ten most commonly-captured species in 2011 were:
1. Yellow-rumped Warbler --818
2. Ruby-crowned Kinglet--639
3. Nashville Warbler --512
4. White-crowned Sparrow --499
5. MacGillivray’s Warbler --355
6. Dusky Flycatcher --292
7. Yellow Warbler --256
8. Chipping Sparrow --225
9. Spotted Towhee --182
10. Western Tanager --176

For comparison, the ten most commonly-captured species for 1997-2011 (15 seasons) combined were:
1. Ruby-crowned Kinglet --15,778
2. Dark-eyed Junco --8,462
3. White-crowned Sparrow --6,439
4. Yellow-rumped Warbler -- 4,497
5. Dusky Flycatcher --4,150
6. MacGillivray’s Warbler --3,984
7. Western Tanager --3,578
8. Spotted Towhee --3,199
9. Nashville Warbler --3,009
10. Chipping Sparrow --2,657

Thus, even though Dark-eyed Junco wasn’t in the top ten in 2011, it’s the second most frequently captured species overall (2011 was the first year ever where Juncos were not in the top ten species). 2011 was an odd weather year, starting with a cool, wet May that caused many migrants to arrive late to breeding grounds. For example, we caught our first fledgling Western Tanagers 1.5 months later than normal. With a few exceptions, it was also a relatively warm fall. Thus, maybe we shouldn’t be too surprised to have seen several unusual shifts in abundance, including record-shattering years for Nashville and Yellow-rumped Warblers juxtaposed with a record low for Dark-eyed Juncos (Junco hyemalis; N = 173) and a near record low for Ruby-crowned Kinglet (one above the previous record low season of 638 in 2009). Importantly, this marks the 5th consecutive season in which we have captured less than 1,000 Ruby-crowned Kinglets after having captured 1,000 or more in 8 of the first 10 seasons.

Though overall totals were below average, we did have record-high capture totals for five species in 2011:
Yellow-rumped Warbler--818
Nashville Warbler--512
Tennessee Warbler--2
American Redstart--3
Song Sparrow--10

Besides the Tennessee Warblers and Redstarts, the only other rarity in 2011 was a Least Flycatcher.
2011 was also the first year in which we banded hummingbirds!

Fox Sparrow

Timberline Brewer's Sparrow

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Mission: to contribute to the conservation of western migratory landbirds through cooperative research and public education