Monday, January 28, 2019

Marsh Sparrow Banding - January 2019

20-25 January 2019

The weather did not cooperate for this month's marsh sparrow banding dates with 4 of the 6 days being cancelled.  Strong winds forced me to cancel on Sunday.  Monday and Tuesday were cancelled due to cold temperatures, and Thursday was cancelled because of rain and extremely windy conditions.  

We spent Wednesday and Friday at the Eagle Point site.  This site is large enough that I usually can only sample half of it before the tide falls, and the birds leave their roosting areas.  Over the course of 2-days we banded 45 new birds and had 21 recaptures.  We captured all three of our target species (Seaside Sparrow, Saltmarsh Sparrow, and Nelson's Sparrow) and as a bonus we banded a few Marsh Wrens, a Sora, some Palm Warblers, and a Common Yellowthroat.

Seaside Sparrows are the most common bird that we capture in the saltmarshes around Kiawah Island.  There are two "recognizable" subspecies that spend the winter in South Carolina.  The migratory subspecies, Ammospiza maritima maritima,  which breeds along the coast from New Hampshire to Virginia and the non-migratory, resident subspecies, A. m. macgillivrayii,  that ranges from North Carolina to northern Florida.    

Seaside Sparrow (macgillivrayii)

This subspecies is on average much darker than the nominate maritima below.  

Seaside Sparrow (maritima)

There are two subspecies of Saltmarsh Sparrows (Ammospiza caudacutus caudacutus and A. c. diversus and ) that spend the winter in the saltmarsh of Kiawah.  We captured both but the photos I took did not really show the differences too well.  Like Seaside Sparrows they are restricted to coastal areas during their entire life cycle.  Caudacutus breeds from from Maine to northern New Jersey and diversus breeds from southern New Jersey to northern North Carolina.  

Saltmarsh Sparrow

There are three subspecies of Nelson's Sparrow that winter in Kiawah's saltmarsh (Ammospiza nelsoni nelsoni, A. n. alterus, and A. n. subvirgatus).  All three subspecies have distinct non-overlapping breeding ranges across the North America.  Plumage differences between the subspecies allow most of the them to be identified however there can be considerable overlap between nelsoni and alterus.

Range map by Cornell University

Nelsoni is he brightest of the three subspecies.  They tend to have more orange in the face and upper breast, have more black in the crown and back, and have the most distinct streaking along the flanks and upper breast.  

Nelson's Sparrow (A. n. nelsoni)
Alterus is a little less brightly colored than nelsoni with less distinct streaking along the flanks.  There is also less black in the crown and back. 

Nelson's Sparrow (A. n. alterus)

Subvirgatus is dullest of the three subspecies.  Most of the orange in the face is washed out with exception to the yellowish loral spot in front of the eye.  The rest of the plumage has a bleached-out appearance.  Subvirgatus is  slightly larger, on average, than nelsoni and alterus.      
Nelson's Sparrow (A. n. subvirgatus)

Marsh Wrens are common inhabitants of the saltmarshes around Kiawah Island.  The local, non-migratory Worthington's Marsh Wren is distinctly plumaged compared to the migratory subspecies (to which there are several).  It is overall a pale brownish gray that lacks the warmer brown and reddish tones of the migratory subspecies.    

Marsh Wren (Worthington's)

Marsh Wren (migratory subspecies)
The Sora was a surprise!  We rarely flush any other rail than Clapper Rails and if we do we rarely catch them.  We have only captured one other Sora during marsh sparrow banding.  That bird was captured on 16 January 2014 also at the Eagle Point site.        

The next marsh sparrow banding date are scheduled for 18-23 February and I am hoping for much better weather. 

I'd like to thank all the volunteers that slogged through the marsh at high tide to help flush the birds into the nets.