Friday, September 16, 2016

Predicting Busy Days

Captain Sam's
A small push of migrants kept us busy for most of the morning at Captain Sam’s today.  We ended the day with a total of 97 birds, of which 92 were new and 5 were recaptures.  Common Yellowthroats, as they always are this time of year, were the most numerous species banded.  We had 14 different species today, including Captain Sam’s first Cape May Warbler of the season. 

Cape May Warbler (after hatch-year, female)
We often try to predict whether or not we are in for a busy day using a couple techniques.  Most nights before bed, a quick check of the radar can give you an idea of what may be in store for the next day.  On a night before a busy morning for us, the radar will often show large patches of migrants taking off from the North Carolina coast.  Last night’s radar looked fairly active, especially compared to what has been going on the last few weeks.  Another good predictor for a busy day is the number of nocturnal flight calls heard.  While birds are migrating at night, they will give short contact calls known as flight calls.  In the morning, we listen for these flight calls while opening the nets.  On busier days, the morning sky is often filled with the chips and zeeps of migrants as they fly over.  Each species gives a unique flight call but they can be hard differentiating just by ear.  By ear, we can usually determine what group they belong to but determining the species is harder and often done with spectrograms, a visual representation of the call.  Today it was surprisingly quiet for what we ended up catching but the birds may have landed earlier in night and were not streaming by overhead. 

- Mattie            

Little Bear
At Little Bear we spent all morning dealing with wind gusts (and weren't able to open 4 nets at all because of the wind), but we still ended up with 61 new birds and 10 recaps of 16 different species--our best day so far of the season.

We also had the site's first Northern Parula of the season. Captain Sam's has had a few so far, but the vegetation at Little Bear is shorter and scrubbier and we tend to catch fewer of the warbler species that prefer treetops.

The water seems to be receding in the areas that flooded from rainfall during Tropical Storm Julia. Nets that had a foot of water beneath them yesterday now have only about 8 inches, and today it was much easier to move along the trails without sloshing water into our rubber boots.

--Blaine

  Species Captain Sam's Little Bear
New Recaps New Recaps
Downy Woodpecker
-
-
-
1
White-eyed Vireo
9
-
7
-
Red-eyed Vireo
3
1
3
-
Carolina Chickadee
-
1
-
2
Carolina Wren
-
-
-
1
Veery
-
-
1
-
Northern Mockingbird
-
-
1
-
Ovenbird
1
-
-
-
Northern Waterthrush
1
-
2
-
Black and White Warbler
1
-
-
-
Common Yellowthroat
56
-
29
-
Hooded Warbler
1
-
-
-
American Redstart
10
-
3
-
Northern Parula
-
-
1
-
Cape May Warbler
1
-
-
-
Yellow Warbler
2
-
3
-
Palm Warbler (Western)
-
-
2
-
Prairie Warbler
3
1
5
-
Northern Cardinal
-
1
-
3
Painted Bunting
4
1
4
3




 Banding Stats Captain Sam's Little Bear TOTAL
# Birds Banded
92
61
153
# of Recaptures
5
10
15
# of Species
14
16
20
Effort (net-hours)
137.5
80.0
217.5
Capture Rate (birds/100 net-hours)
70.5
88.8
77.2
Nets
26
16
42

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