Tuesday, July 28, 2015

Winging it

As our internship is nearing an end, Krista and I have begun analyzing photographs and data to turn our summer's work into lasting research. Short-term we have been refining photography techniques so that our photos of wings, tails and individual feathers are clear and useful down the line.
Long-term we are looking at improving aging techniques in wood thrush. The current guidelines seem inconsistent to Bishop, so we will be looking for patterns in the changes of wing feathers as the birds age.

For most every bird we catch, we take a "mugshot,"

Field sparrow
Brown creeper

Rose-breasted grosbeak male

pictures of both wings,

Displaying CEDW 244123730-3.JPG
Cedar waxwing 
Yellow-bellied sapsucker
Brown creeper
Grackle (in heavy molt)
Indigo bunting male
Red-wing blackbird

a tail shot,

Baltimore oriole juvenile


and if the bird is an unusual catch or has peculiar body feathers we'll take some extra pictures.

Red-wing blackbird juvenile 

Yellow-bellied sapsucker 
Thrush, like the wood thrush and the robin have one more primary covert feather than other song birds. The changing shape and length of this "p10" through the years may help us better age the birds in the future. For now, we are testing tactics to have consistent, high quality shots of the small feather. This means maintaining it's natural shape, displaying the other primary coverts and including a scale in the shot. 

Wood thrush p10
Our first step toward new aging techniques in the wood thrush will be looking at the lighter, buffy tips in the primary and lesser coverts to establish a scale of the color and shape range. If we see consistent patterns in the tips (such as  shrinking in size and fading in color) between hatching year, second year and after second year birds, we could develop a better idea of how to determine the age of wood thrush. 

Wood thrush wing
If we succeed, the data that Bishop collects on the birds will become more accurate and better contribute to future bird research and bird demographics.

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