Monday, October 31, 2016

Eastern Towhee preformative molt

CAPTAIN SAM'S

Bird activity was much better than I thought it was going to be today with 50 new birds and 25 recaptures of 13 different species.  Thank goodness for the Yellow-rumped Warblers or else today would have been kind of a drag.  During the first net round, we captured 3 male Eastern Towhees.  After examining them to determine their age, we discovered that all three were hatch-years because we detected molt limits within/between feather tracts on their wing.  What made this encounter interesting was being able to compare the variation in the extent of the preformative (first prebasic) molt in these three Eastern Towhees.

-Aaron


This individual replaced all lesser, median, and greater coverts in addidtion to the carpal covert and the first alula (A1).  Notice the molt limit between the replaced black greater coverts and the brownish unreplaced primary coverts.  This bird also replaced its inner secondaries (s6-9) but no primaries or primary coverts.  

This individual is exhibiting an eccentric molt pattern.  it has replaced all lesser, median, and greater coverts in addition to the carpal covert and all three alulas.  It has a more extensive molt of its flight feather replacing the inner secondaries (s5-9) and outer primaries (p5-9).  Additionally it replaced some of its outer primary coverts as well leaving a clear molt limit between the outer and inner primary coverts.  

This individual had the most extensive preformative molt of the three.  This individual has replaced all lesser, median, and greater coverts in addition to the carpal covert and all three alulas.  It replaced some inner secondaries (s6-9) and all of its primaries (s1-9) and primary coverts leaving of block of unreplaced feathers in the middle of the wing (s1-5).  Notice the color difference between the brown unreplaced feathers and the black replaced feathers. 

LITTLE BEAR
Things were about the same at Little Bear, with 50 new birds and 20 recaptures of 14 different species. In keeping with the pattern of the past few days, almost all of the birds were captured within the first two hours, after which things got slow and hot. After the cold front last weekend we had thought we were done for the season with having to shut down early due to heat, but apparently the weather has other ideas right now.

--Blaine


 SpeciesCaptain Sam'sLittle Bear
NewRecapsNewRecaps
Yellow-billed Cuckoo
2
-
1
-
Downy Woodpecker
-
1
-
1
House Wren
-
-
1
-
Golden-crowned Kinglet
1
-
-
-
Ruby-crowned Kinglet
3
1
1
-
Gray Catbird
2
11
9
13
Brown Thrasher
-
-
-
1
Orange-crowned Warbler
1
-
-
-
Common Yellowthroat
-
-
2
-
Palm Warbler (Western)
1
-
4
-
Yellow-rumped Warbler (Myrtle)
30
7
24
1
Eastern Towhee
1
2
-
-
Song Sparrow
3
-
1
-
Swamp Sparrow
3
-
4
-
Northern Cardinal
-
2
1
1
Indigo Bunting
-
-
2
-
Painted Bunting
3
1
-
2




 Banding StatsCaptain Sam'sLittle BearTOTAL
# Birds Banded
50
50
100
# of Recaptures
25
19
44
# of Species
13
14
17
Effort (net-hours)
130.5
90.0
220.5
Capture Rate (birds/100 net-hours)
57.5
76.7
65.3
# of Nets
26
20
46


Banding Staff
Aaron Given (CS)
Blaine Carnes (LB)
Alison Nevins (LB)
Col Lauzau (LB)
Michael Gamble (CS)
Michael Rodgers (LB)
Ryan Donnelly (CS)
Nancy Raginski (CS)