This was yesterday, before the storm hit, 7:30pm over the school. Maybe 300 migrating Mississippi Kites coming back from Central and South America on their way up the Plains that just happened to run out of daylight over the West Side. What they do is circle lower and lower (real low wing loading) looking for trees to roost in, these birds were maybe 150 ft overhead.
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Then 300 kites descend upon the neighborhood right in back of the school, pitching into trees in peoples' yards. Not many people took note, that's the way it usually is with bird stuff. This bunch flushed out of a tree when someone walked by.
Cool. I didn't know raptors flocked up like that.
Mississippi Kites, Swainson’s Hawks and Broad-wings all migrate in flocks. Going south, Mississippi’s prob’ly catch a lot of high-flying dragonflies, which also migrate. It is believed Swainson’s and Broad-wings fast during migration.
Broad-wings, forest hawks year-round, depend upon late summer frogs and toads to fatten up before migration. In Central America it takes the ecological slot between the slightly larger grey hawk and the slightly smaller roadside hawk. Basically when all three require more prey during the breeding season, the broad-wing removes itself from the equation to access untapped resources in North America.
The Swainson’s Hawk, big as a red-tail but half the weight, is actually a grasshopper and cricket specialist. In summer they switch over to rodents when raising young. Red-tails, being heavier and stronger, can chase them off. But red-tails need perches to hunt from when it ain’t windy, Swainson’s can hunt from the wing whatever the weather so occupy open areas that red-tails can’t.
Some Swainson’s in San Antonio have switched to urban areas, robbing grackle and white-winged dove nests instead of catching rodents.
In late summer Swainson’s form wandering flocks looking for grasshopper and cricket outbreaks. They have to put on enough fat to last up to a month without eating. They go clear down the Andes to Argentina where they feed on grasshoppers and crickets down there too, still wandering around in flocks.
Who has it rough in Broadies and Swainson’s both are the young of the year. Just out of the nest, still growing feathers, and they have to put on enough wait in just weeks to survive migration. They start turning up dead or too weak to fly in numbers at the overnight stopover points in Mexico and points south.