Summer Sampling

The Summer is really just getting going…..right? Wrong! for most bird species the Summer has pretty well ended and it’s time to think about heading south again. Mid- to late-July is a good time to band at Ruthven Park. Most young birds have fledged and are following a parent around begging for handouts or have just recently been cut loose and are now on their own. At this point they are beginning to wander – to “disperse” – checking out the immediate vicinity so they’ll know where to come back to and learning how to forage independently while avoiding predators. This is a critical time for young birds and many are not successful (1st year mortality rates are in the area of 80%!). Sometimes young birds do more than check out the immediate vicinity. It is at this time that you begin to get reports of sightings of species way outside of their normal range. Usually these sightings are of young dispersing birds who have either made a poor decision or are genetically wired differently.

All of the birds – young and old – are molting right now. Most juvenile birds will molt only some body feathers and wing coverts but not their (relatively new) wing and tail feathers. Most adults, on the other hand, go through a “complete” molt replacing all their feathers, especially the all-important flight feathers. At this time they can look pretty scruffy and their flight capacity can be greatly diminished – a reason that they are pretty quiet when molting.

I like to band at this time to get a sense of how successful the breeding season has been and to mark young birds to see how many of what species return to their natal area. Also, if I don’t get out now the Yellow Warblers will be gone – we rarely catch a Yellow Warbler after the first week of August. All of “our” Yellow Warblers have gone south by then (and they’re getting ready to go now). I had one very interesting result today from this practice: one of the retrapped Yellow Warblers was originally banded as an AHY (after hatch-year) female on July 27th, 2000. So this bird has to be at least 8 years old!!! Think of what this bird has seen and experienced as it has travelled back and forth between Ruthven and its main home in Latin America!

Some of the birds caught today were in family groups; for example, the 3 Orchard Orioles reported were young birds all in the same net with the retrapped adult male; one grouping of 4 young Yellow Warblers was with an adult male and female – both molting heavily. (In these situations, we try to release the “family group” at the same time after banding.)

Banded 56:
1 Downy Woodpecker
1 Least Flycatcher
1 Blue Jay
2 Black-capped Chickadees
8 Gray Catbirds
2 Cedar Waxwings (an adult and young bird caught together)
1 Red-eyed Vireo
1 Blue-winged Warbler
19 Yellow Warblers
1 Ovenbird (an adult molting heavily)
1 Common Yellowthroat
2 Rose-breasted Grosbeaks
2 Field Sparrows
5 Song Sparrows
1 Red-winged Blackbird
3 Orchard Orioles
4 Baltimore Orioles
1 American Goldfinch (these are late nesters – the absolute hordes of young birds will not be upon us for a couple of weeks yet)

Retrpped 14:
1 Downy Woodpecker
1 Wood Thrush
3 Yellow Warblers
1 Common Yellowthroat
1 Northern Cardinal
2 Song Sparrows
1 Brown-headed Cowbird
1 Orchard Oriole
1 Baltimore Oriole
2 American Goldfinches


Here is a picture of a nice looking ASY (after second year) Male Scarlet Tanager that was taken at Ruthven last week. There are a few more in the photo gallery.


One thought on “Summer Sampling

  1. This pair of Scarlet Tanagers was caught at the same time in the same net. The greenish-coloured bird is a young male (a careful look will show that it has black wing coverts). The young bird was with the adult male, probably still being fed. This was a gratifying catch. Two years ago I saw a beautiful male Scarlet Tanager feeding a young………Cowbird! Very disappointing.

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