Tuesday, January 17, 2012

Will La Niña Influence Spring Migration?

The roller coaster weather continues.  Today, almost 70, tomorrow only a high of 49 is expected.  The weather effects of La Niña are expected to continue through March.  The milder winter has had a noticeable affect on the number of migratory warterfowl and songbirds that normally winter over.

By this time last year, we had already received a couple of rounds of snow (granted not that much in our area) and January was a miserably cold month.  This year, two weeks before the end of January,  I still have petunias blooming out on the deck.

There has been a noticeable decrease in the number of Yellow-Rumped Warblers, Juncos, Kinglets and even White-Throated Sparrows which are generally everywhere in winter.  Last year it was not unusual to look out at the suet feeder and see 5 of 6 YR Warblers clinging to the feeder at one time.  This year I feel lucky to see one or two in a week.

I have to wonder how or if this will influence the arrival and departure times during spring migration.  Will those that arrive early be even earlier?   Time will tell. 
Timelines for March Arrivals

Arrive       Depart       Bird         (approximate dates)
--------       20-Feb      Lapland Longspur
8-Mar       ---------      Chipping Sparrow
--------      15-Mar      Fox Sparrow
18-Mar      3-May      Henslow's Sparrow
26-Mar     --------       Yellow-throated Warbler
27-Mar     --------       Black-and-white Warbler
27-Mar     --------       Black-throated Green Warbler
30-Mar     --------       Common Yellowthroat
31-Mar     --------       Louisiana Waterthrush
31-Mar     --------       Palm Warbler

Timelines for April Arrivals

Arrive        Depart       Bird 
---------      4-Apr        Song Sparrow
8-Apr        ---------      Northern Parula
---------      12-Apr      Dark-eyed Junco
12-Apr     ---------       American Redstart
13-Apr     ---------       Yellow Warbler
14-Apr     ---------       Ovenbird
14-Apr     ---------      White-crowned Sparrow
15-Apr     ---------       Prairie Warbler
18-Apr     ---------       Hooded Warbler
18-Apr     ---------       Prothonotary Warbler
19-Apr     ---------       Grasshopper Sparrow
21-Apr    28-Apr        Le Conte's Sparrow
23-Apr     ---------      Yellow-breasted Chat
24-Apr     ----------     Northern Waterthrush
24-Apr     ----------     Worm-eating Warbler
27-Apr     19-May      Black-throated Blue Warbler
28-Apr      ---------     Chestnut-sided Warbler

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