Saturday, August 25, 2012

Saturday's Results & ageing Northern Waterthrush

Clear skies + cooler morning + north winds =  lots of birds.  Not today, though.  Despite what seemed like ideal conditions, we only banded 18 new birds with 6 recaptures of 11 different species.  Empidonax flycatchers appear to be on the move with 3 of them banded today - 2 "Traill's" and 1 Acadian.  This is only the 2nd Acadian Flycatcher ever banded at KIBS and the first this season.  At a later date, I will put together a post explaining how banders are able to separate the incredibly similar Empidonax flycatchers.     

Acadian Flycatcher (hatch-year, sex unknown)

We have been banding a lot of Northern Waterthrushes lately, so I thought I would explain how banders can distinguish between young (hatch-year) and adults (after hatch-year).  The key is to look at the tertials.  The tertials are the last 3 secondaries on the wing closest to the body.  

Tertials on a Northern Waterthrush

Hatch-year birds will have buffy edging on the tertials while adults will lack the buffy edging.However, late in the fall there is a chance that the buffy edging can wear away and they will look adult, so it's always a good idea to check the primary coverts for shape and wear.  In the following photo, the bird on the left is an adult and the bird on the right is a juvenile.  Notice the buffy edging on the tertials on the hatch-year bird on the right.  This trick also works for determining the age of Ovenbirds except the egding on the tertials is more of a rusty color.    

Northern Waterthrush




5 Prairie Warbler

2 Northern Waterthrush

1 American Redstart

1 Common Yellowthroat

2 "Traill's" Flycatcher

1 Acadian Flycatcher

1 Red-eyed Vireo

3 Painted Bunting

1 Northern Mockingbird

1 Northern Cardinal



3 Painted Bunting

2 Carolina Chickadee

1 Northern Waterthrush



Effort:  50.0 net-hours

Capture Rate:  48.0 birds/100 net-hours

# of Nets:  10

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