Wednesday, November 16, 2016

November 16, 2016

Captain Sam's
It was a pretty consistent morning out at Captain Sam's with 34 new birds and 24 recaptures of 12 species. Almost half of the recaptures were banded in previous years, the majority of these being Yellow-rumped Warblers. We also caught a couple more Golden-crowned Kinglets, which must have had a good year as it seems we are hearing and catching more than last year.

Also, there has been a Loggerhead Shrike hanging out behind the banding table the last few days. We set up another net and tried to lure him in, but he has outsmarted us and has avoided getting caught in any of our other nets. Loggerhead Shrikes eat a variety of food, which includes insects, amphibians, reptiles, small mammals, and even other birds. Even though they're small, they can kill and carry an animal that is as large as themselves. Loggerhead Shrikes are known for their behavior of impaling prey on objects before eating them. They will do this with poisonous prey, like monarch butterflies, and wait up to three days before eating it to allow for the toxins to break down. Hopefully we get lucky and catch this one in our nets!

-Michael Gamble

Little Bear
At Little Bear today we had 38 new birds and 13 recaptures of 12 different species. Yellow-rumped Warblers dominated the total, making up over 80% of the new birds and a little under one-third of the recaptures. The first couple of hours were pleasantly cool and foggy, and we were treated to the sound of a calling Common Loon somewhere out on the ocean in the fog.

This season you may have noticed the occasional (Myrtle) inserted into the species table in the row for Yellow-rumped Warbler. Currently, Yellow-rumped Warbler is thought of as one species consisting of 4 distinct subspecies in different areas of North America, but this was not always the case. Prior to 1973 the birds that breed throughout the boreal forest and winter in the eastern US were known as "Myrtle Warblers" and the birds that breed in the Rockies and other western mountain ranges were called "Audubon's Warblers". The discovery of a small hybrid zone in the Canadian Rockies in the early 1970s caused ornithologists to merge the two species under one name: Yellow-rumped Warbler.

Several other species were "lumped" in 1973 as well, such as all the subspecies groups of Dark-eyed Junco, all forms of flickers in North America, and Baltimore and Bullock's Orioles (which were given the new name of "Northern Oriole"). Since then, genetic data has shown that Gilded Flicker is very distinct from the Red-shafted and Yellow-shafted forms that make up Northern Flicker, and that Baltimore and Bullock's Orioles are not even each others' closest relatives. A type of junco that occurs only on one island off the coast of Baja California has been split off into its own species as well: Guadalupe Junco.

A number of recent genetic studies has indicated that what we now call "Yellow-rumped Warbler" is likely made up of at least three and possibly four distinct species. If ornithologists continue to confirm these findings over the next few years, then the old Myrtle and Audubon's names will come back, as well as species designation for a nonmigratory group found only in the highlands of Guatemala and far southeast Mexico ("Goldman's Warbler"). It's possible that the group found in the mountains of western Mexico ("Black-fronted Warbler") will be split as well, but that group has received less study than the other groups.

Yellow-rumped Warbler (Myrtle), After Second Year male in Canada
Yellow-rumped Warbler (Audubon's), After Second Year male in California



Pretty different-looking, aren't they? Myrtle has a black mask, a white eyebrow, and a white throat. Audubon's has a gray face, no eyebrow, and a yellow throat, plus more black on the body, more white in the wings, and they're typically larger than Myrtles. The songs of the two groups are different too.

So by keeping track of current subspecies group we've prepared the data for the likelihood of an official split between the two species. Plus, the name "Myrtle Warbler" is so much more appropriate and specific for the South Carolina coast than the more general "Yellow-rumped Warbler".

--Blaine



  Species Captain Sam's Little Bear
New Recaps New Recaps
Yellow-bellied Sapsucker
1
-
-
-
Eastern Phoebe
-
-
1
-
Blue-headed Vireo
1
-
-
-
Carolina Chickadee
-
1
-
1
House Wren
-
-
-
1
Carolina Wren
-
-
-
1
Golden-crowned Kinglet
2
-
-
-
Ruby-crowned Kinglet
5
2
1
2
Hermit Thrush
2
1
-
-
Gray Catbird
-
6
-
2
Orange-crowned Warbler
1
2
1
-
Common Yellowthroat
-
1
-
-
Palm Warbler (Western)
-
-
1
-
Yellow-rumped Warbler (Myrtle)
22
8
32
4
Eastern Towhee
-
-
-
1
Song Sparrow
-
-
1
1
Swamp Sparrow
-
2
1
-
Northern Cardinal
-
1
-
-




 Banding Stats Captain Sam's Little Bear TOTAL
# Birds Banded
34
38
72
# of Recaptures
24
13
37
# of Species
12
12
18
Effort (net-hours)
164.7
120.0
284.7
Capture Rate (birds/100 net-hours)
35.2
42.5
38.3
# of Nets
26
20
46


Banding Staff
Aaron Given (CS)
Blaine Carnes (LB)
Mattie VandenBoom (CS)
Alison Nevins (LB)
Col Lauzau (LB)
Michael Gamble (CS)
Ryan Donnelly (CS)