Thursday, December 13, 2012

Tucson Valley's Nine National Highs in 2011

The Tucson Valley Christmas Bird Count now almost every year leads the nation in four species: Cooper's Hawk, Gila Woodpecker, Vermilion Flycatcher, and Verdin. The first and the last are growing in numbers every year, and last year's 86 Cooper's Hawks was an all-time national high.
Tucson Valley CBC leads the nation in Cooper's Hawk numbers every year.
Twenty-one years of data from the Tucson Valley CBC. These are raw numbers, not corrected for observer effort.
We've been close to the all-time high for Vermilion Flycatcher: our count reached a high in 2010 with 102 birds, while the record is held by the Kingsville, TX CBC, with 116 tallied in 2003. They've not had numbers anywhere like that since (only 25 last year), and I'm seeing record numbers in my own back yard this winter. I think we'll be tallying over 100 this year. The U of A Farm on Roger Road just 50 yards from my mailboxes had 14 this past month; back in 2000 when I first started birding there, it was a rare bird in the neighborhood. On the Urban CBC Birding Workshops I led earlier this month, we began with a pair by the parking lot, tallied at least two other pairs around the same baseball field, and finished with a pair behind Robison Elementary School. They are everywhere this year. If every area tallies just 5, we'll break the all-time high.
Everyone loves the Vermilion Flycatcher – easy to spot and easy to identify.

The U of A Farm on Roger Road has boasted an increasing, year-round population of Vermilion Flycatcher.

 We're lucky that Gila Woodpecker and Verdin have been able to adapt so readily to our urban environment, so rich in exotic and poor in native plants. I think we'll have no problem garnering first place with those once again.
Gila Woodpeckers are successful colonists of Tucson's urban habitats.
The Black-tailed Gnatcatcher isn't so adaptable and in our circle is found only in the natural desert areas in the northern and western parts. The Salt-Verde River CBC is the nation's leader in this species, hands down. In recent years, several pairs have colonized the Rillito River wash in Tucson. The trend for our circle looks like a decline over the past 20 years, so I'm curious to see how many we'll get this year.
The Black-tailed Gnatcatcher isn't one of Tucson's specialties, but it is a good example of a desert species that has not adapted to the urban environment.

Only CBC counters who have native desert will get numbers of Black-tailed Gnatcatcher
Last year Tucson Valley also garnered the national highs in Violet-crowned Hummingbird, Plumbeous Vireo, Cassin's Vireo, Phainopepla, and Chestnut-sided Warbler, placing it among only 8 other CBCs in the contiguous United States to have 9 or more national highs (Hawaii automatically gets a bunch – unfair competition). We might get three of those this year (the vireos and the warbler), but so far my Violet-crowned Hummingbird hasn't returned this winter, and it doesn't look like a big year for Phainopepla in these parts.
This Violet-crowned Hummingbird returned to Rich Hoyer's Tucson yard for 5 winters; it hasn't appeared yet this winter.

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