Another(!) beautiful day…with the temperature rising in the afternoon to 28. And almost NO wind…all day. The only hint of coming change was the presence of cloud, which at times took up 30% of the sky. Not heavy cloud, just cloud, but enough to give one hope that this marvellous weather might change and bring in a flood of migrants.

We had sightings of 3 “new” birds: the first Pileated Woodpecker of the year; the first Rusty Blackbirds of the season; and a Great Egret sporting blue wing markers.

But the most noticeable thing was the very large flocks of Common Grackles (with a few other species mixed in – small numbers of starlings, Red-winged Blackbirds and the two Rusty Blackbirds). We estimated that one flock numbered at least 1500 birds and this was likely a conservative estimate. There were at least 2500 grackles around the site. They came from a roost somewhere to the southwest (possibly Taquanyah) and headed NE over Ruthven. A large group stopped in the treetops above Rick’s Rill and made a heck of a racket. I’m not sure what they were feeding on in the treetops but they might have been adopting the same strategy I watched Rusty Blackbirds employ last Fall: the birds would stay in the treetops, seemingly keeping watch, while groups of individuals would drop to the understory to eat berries and grapes and then ascend to the treetops as others dropped down to eat. Birds of this size would make a good meal for migrating accipiters, so having many lookouts would be a good strategy. The impact of groups of this size on the berry crops must be enormous – they would strip away thousands of berries and grapes in a fairly short time. Evidence that they might be using this strategy is that we caught and banded 16 – in nets with grape clusters around them. Sixteen might not seem like a lot of birds (only 0.6% of the estimated total in the area) but our nets have a mesh for catching and holding smaller passerines (warblers, sparrow, flycatchers, etc.) not these big brigands. In fact, I think we saw more escape from the nets as we approached them than we actually caught. After about an hour, the birds lifted off and headed back to the SW.

Banded 46:
1 Mourning Dove
1 Yellow-bellied Sapsucker
1 Blue Jay
1 Winter Wren
1 Ruby-crowned Kinglet
3 Swainson’s Thrushes
3 Hermit Thrushes
6 American Robins
1 Magnolia Warbler
1 Blackpoll Warbler
1 Common Yellowthroat
1 Chipping Sparrow
1 Field Sparrow
2 Song Sparrows
5 White-throated Sparrows
16 Common Grackles
1 American Goldfinch

ET’s: 47 spp.

Images by Ezra Campanelli:

Rick