Friday, August 24, 2012

Friday's Results

Rain delayed the opening of net until 7:30 this morning, however I was able to get an extra hour of sleep!  Bird activity was horrible slow with only 10 new birds banded with 3 recaptures of 5 different species.  Northern Waterthrush and Red-eyed Vireos were the most abundant today making up 90% of the catch. 


Yesterday I mentioned that you can use eye color to age Red-eyed Vireos in the fall.  Up until today, I had not banded an adult yet this season.  The following pictures are of a hatch-year and an after hatch-year Red-eyed Vireo, showing the difference in eye color between the age groups.  The red eye in the photo of the adult was much redder in person.  It appears to have been washed out a bit in the photo.    

Red-eyed Vireo (hatch-year, sex unknown) - notice the brownish colored eye

Red-eyed Vireo (after hatch-year, sex unknown) - notice the red eye

 In addition to eye color, plumage characteristics can also be useful in ageing Red-eye Vireos.  They have somewhat of a unique molting pattern where adults start their prebasic molt on the breeding grounds, suspend their molt during migration, and complete it on the wintering grounds.  Most other adult passerines finish their prebasic molt prior to fall migration.  Adult Red-eye Vireos will show a contrast in feather wear and color among wing coverts and sometimes flight feathers, while juveniles (hatch-year) will have a fresher, less contrasting looking wing plumage.  




5 Red-eyed Vireo

4 Northern Waterthrush

1 Prairie Warbler



1 Prairie Warbler

1 Northern Cardinal

1 Northern Mockingbird



Effort:  30.0 net-hours

Capture Rate:  43.3 birds/100 net-hours

# of Nets Used:  8    

No comments:

Post a Comment