The morning started off at 8 degrees, heavy overcast, brief light showers accompanied by flashes of lightening in both the north and south, and a relatively light SE wind; it finished with a gusting SW wind, blue skies and a temperature of 26 degrees – all in the space of about 7 hours.
This had to be good news for nesting birds which had taken a serious hit over the past two days. I heard of several batches of bluebird nestlings wiped out. Christine and Chris, who are monitoring all the boxes on Ruthven’s property, reported that 18% of the over 400 Tree Swallow eggs in the boxes had been destroyed by House Wrens. The connection with the weather? One parent at a time goes out to forage leaving the other to guard the nest against House Wrens. In bad conditions both parents are sometimes forced to leave at the same time just to survive, leaving the eggs easy prey to the wrens which want to take over the boxes.
The migration was quite noticeable here today. One of the phenomenon I’ve seen over the years is that when the warblers are here and on the move we band a lot more birds from nets 5, 6 6A and 7 as opposed to the nets in the proximity of the feeders. Today those nets, which have been largely silent, produced 58% of the banded birds. The “feeder nets” – 1, 1A, and 2 produced less than 12%. This was the first time this season this has been the case. Further, the 25 warblers we ringed made up 58% of the total number of birds banded. Thank goodness things seem to be getting into gear! Perfect for the holiday weekend.
One interesting phenomenon we’ve been looking at is the number of Rose-breasted Grosbeaks we handle here. We have banded 24 “new” ones but we have handled a total of 39 – 15 of these being retraps from previous years including two from 2009 and one from 2007 (a SY or “second year” bird, making it 7 years old!). These birds show really good site fidelity . It would be interesting to put geolocators on some of them to see the routes they use to migrate and the areas they spend the Winter in.
Banded 43:
1 Traill’s Flycatcher
1 Ruby-crowned Kinglet
4 Gray Catbirds
2 Warbling Vireos
1 Blue-winged Warbler
3 Nashville Warblers
11 Yellow Warblers
3 Magnolia Warblers
2 Cape May Warblers
3 Myrtle Warblers
2 Common Yellowthroats
1 Rose-breasted Grosbeak
1 Chipping Sparrow
1 White-throated Sparrow
2 Eastern White-crowned Sparrows
2 Baltimore Orioles
3 American Goldfinches
Retrapped 26:1 Red-bellied Woodpecker
1 Tree Swallow
1 Eastern Tufted Titmouse
1 White-breasted Nuthatch
1 American Robin
1 Blue-winged Warbler
5 Yellow Warblers
2 Common Yellowthroats
2 Rose-breasted Grosbeaks
3 Chipping Sparrows
1 Field Sparrow
2 Song Sparrows
1 Brown-headed Cowbird
2 Baltimore Orioles
2 American Goldfinches
ET’s: 66 spp.
Rick
Wow, I guess I should stop hoping for a House wren….it’s just that they’re so chatty! 400 eggs! How many boxes do you maintain at Ruthven? Do you pair the boxes? Mine are paired, but the bluebirds don’t seem to take advantage of them….just reduces swallow occupancy by 50%. I’ve had bluebirds in the boxes, but usually only once the swallows have finished.