September 2nd – The Advisability of Multiple Methodologies

There’s been a lot of discussion over time around what is the best way to monitor how many birds are at a site at any given time. Do point counts give you a good idea? A census route repeated daily? Banding totals for the day? No one method is better than another but together they can give a pretty reliable picture of the types and numbers of birds that are around. This is why the Canadian Migration Monitoring Program (in which Ruthven is a participant) has adopted banding totals and a census count to help come up with “Estimated Totals” (ET’s) for each species each day. The two work together.

Today was a good case in point. If you had asked me after the census walk if there were many birds around, I would have answered emphatically ‘no’. After an hour I had encountered only 22 species, none of them warblers. At times during the walk I was musing about Stutchbury’s Silence of the Songbirds or Rachel Carson’s Silent Spring as the woods seemed so quiet….and so empty. And there was virtually nothing along the river. However, when I got back to the banding lab I found that Faye had loaded up the hooks with bird bags. We ended up banding 51 birds of 26 species, 11 of them warblers. At this time of year, they tend to be quiet and somewhat reclusive, skulking in the thick second growth where the nets tend to be – easy to overlook. However, if you went just with banding totals you would have missed the Caspian Tern, Osprey and Great Blue Heron by the river. But put both methods together and you get a respectable count of 52 species for ET’s.

Banded 51:1 Hairy Woodpecker
2 Yellow-bellied Flycatchers
1 Black-capped Chickadee
1 Eastern Bluebird
1 Veery
1 Wood Thrush
1 Warbling Vireo
1 Yellow-throated Vireo
8 Red-eyed Vireos
1 Blue-winged Warbler
3 Tennessee Warblers
6 Magnolia Warblers
2 Black-throated Blue Warblers
1 Black-throated Green Warbler
7 Bay-breasted Warblers
1 Blackpoll Warbler
3 Black & White Warblers
1 American Redstart
2 Ovenbirds
1 Wilson’s Warbler
1 Northern Cardinal
1 Rose-breasted Grosbeak
1 Indigo Bunting
1 Song Sparrow
1 House Finch
1 American Goldfinch

Retrapped 9:
1 Downy Woodpecker
1 Black-capped Chickadee
1 Gray Catbird
1 Yellow-throated Vireo (originally banded 2007; last handled September 2, 2009)
2 Blue-winged Warbler
2 Magnolia Warbler
1 Bay-breasted Warbler

ET’s: 52 spp.


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