Hi Cobirders,
We are deep into planning for fall migration banding at Barr, so I thought I’d better do a final wrap-up on spring at Chatfield! You can learn more and view some cool photos on the RMBO blog (http://rmbo.org/v3/Home/tabid/41/EntryId/63/Two-Birds-Recovered-at-Spring-Banding-Stations.aspx), but here are some highlights:
· We caught 742 individual birds. 680 birds that we banded new this year, 61 that had been banded by us in prior years, and 1 banded elsewhere. A fairly “normal” year, in terms of numbers. A relief after last year, when the mild winter and warm weather brought an early spring with plants and insects out of sync, and the migrating birds just seemed to pass us by.
· The numbers and mix of species was slightly unusual. Swings in weather, while not usually good for birds, often make for more interesting banding:
o More early season migrants: Our first week is normally our slowest, but this year it was the busiest because of the April 1st snowstorm. That weather shift meant we caught more of some early species – record numbers of Hermit Thrushes and Orange-crowned Warblers, as well as lots of Yellow-rumped Warblers, both Audubons and Myrtles. Our first-week visitors got a great opportunity to study the differences between these two sub-species, plus seeing several intergrades.
o Fewer Flycatchers and House Wrens: Flycatchers of all species were down, as were House Wrens. These are two groups that were way down last year and did not show the return to more “normal” numbers that we saw with most other species.
· Lots of returning birds: Chatfield is a nice stop-over spot for migrants, but for many birds it is their summer home. Ten percent of the birds we caught had been banded by us in some prior season. Half of those were Yellow Warblers; 25% of all the Yellows we caught had been previously banded by us. Our 3 oldest returning birds, 2 Yellow Warblers and a Yellow-breasted Chat, are at least 9 years old - they were banded as adults (all males) in 2006, meaning they hatched in 2004 or before. 2006 was our first year in this location, so we look forward to setting some longevity records in the years to come. (The Bird Banding Lab shows the longevity record for Yellow Warblers as 11 years.)
· A banded Broad-tailed Hummingbird! A “recovery” is a bird we catch that was banded at another station. This doesn’t happen very often, but when it does it provides valuable information about migratory patterns. On May 15, we caught a pair of Broad-tailed Hummingbirds in the same net. I released the female, then started to show the male to a group of young children out with their parents. There, on its tiny leg, was a band! I turned the data in that evening to the Bird Banding Lab, and by morning I knew it had been banded in the fall of 2010, as a hatch-year bird, at a big hummingbird banding operation in the Davis Mountains near Fort Davis, Texas. According to the bander, many young Broad-tailed Hummingbirds linger there in the fall before completing their migration down to Mexico.
The official opening day at Barr Lake will be Saturday, August 31. Have a great summer, and I’ll look forward to seeing many of you this fall!
Meredith
Meredith McBurney
Biologist/Bander
Rocky Mountain Bird Observatory
303-329-8091
Celebrating 25 Years of Bird and Habitat Conservation
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