Archive for July, 2008

2008 Hummer House Trip

19-23 June

Sue and I left Victoria at 3:30 a.m to meet Ann Lemon at her ranch near Segovia to sample her hummers. We enjoyed visiting with Ann and catching Black-chins with a hill top view. Many Painted Buntings and other seed eaters visited her grain feeders while we worked the hummers. Our sample goal was 100 which we achieved by 10 a.m. Her population appeared to have slowed down in breeding for the season because only 26 of 57 adults were male. The normal sex ratio is 1:1 and males tend to leave when they do not get enough attention. 67% of adult females showed tail wear indicating they probably fed young and 17% of our sample was comprised of young birds. 13 of the adults captured had been banded during previous trips. We ate a nice breakfast at one of the best Junction restaurants and watched a waitress balance raw eggs on their ends which is reported as to be only possible during the summer solstice.

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We caught 636 Black-chinned Hummingbirds on 20 June 2008 at the Brown Ranch. This was the 2^nd highest hummingbird catch for the Ranch. Songbirds were much lower than normal (<400) and their scarcity allowed banders to focus more intensively on catching hummers. We recaptured about 88 hummers from previous years. This was the 3rd year in a row of lower than expected production of young. There was a severe hail storm during spring 2006 that probably killed birds, there was a major freeze in early April 2007 that probably destroyed all nesting attempts at the time. 2008 had much lower rainfall than normal which should lead to lower production and higher dependency of birds on feeders. Adult male to female sex ratios was about 45% male which is about normal for this site and date. It contrasts greatly with ratios from neighboring ranches and shows the significance of this property by being able to support reproduction of high densities of birds late into the season. Win and Beck ranches nearby feeders had a much higher percent of adult females and indicates that breeding is finishing up for the season earlier at these sites than at the Hummer House.

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INDEPENDENCE CREEK

Chandler Ranch

21 - 23 JUNE 2008

After banding at Dan & Cathy Brown’s Hummer House on 20 June, Ross Dawkins and I continued our expedition by traveling to the Chandler Ranch in Terrell County. We netted on the south side of Independence Creek near its confluence with the Pecos River. Conditions were hot and very dry. There was still a good clear flow in the creek. We focused netting near the “slab” on the first day having to keep most nets in total shade because of 100+ degree temperatures. The 2^nd day, we shifted unproductive nets and all nets near the river westward towards the “shady grove” area. We caught about 300 individuals of 30 species. Yellow-breasted Chat, Painted Bunting, Blue Grosbeak and Bell’s Vireo were the dominant species in the baccharis dominated riparian zone. Black-capped Vireo and Green Kingfisher occurred in relatively high numbers. We caught a Black-capped Vireo that was banded during an earlier study that was at least 8 years old.

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We finished our last banding run of the season during late June in the eastern Hill Country with the Burditt Ranch feeding 3.7 gallons of sugar water per day, Matter Ranch 1 gallon per day and Wiedenfeld Ranch 2 gallons per day. The breeding season is starting to show signs of winding down with adult males starting to leave the mega feeding stations. Reproduction looked good for the season with all ranches showing about 50% young during the last check and ¾’s of the adult females showing some tail wear which is normally indicative of having fed young. Total capture of birds this season was below those of the record year of 2007 and collectively at least as high as the other previous years. We had one day of strong winds which lowered catch and tallies for the year.

The last round of the season netted two very interesting birds. The first was a male that was banded as a hatch year at Dan Brown’s Hummer House Ranch near Christoval in 2004. It was caught again at that ranch in 2006 and 2007. However, this year they did not catch it at Dan’s, and we caught it at the Burditt Ranch in late June. Our data has shown over the years that males are more prone to switch breeding areas and we suspect this bird did this. The 2^nd bird was banded as an adult female at my Victoria County banding station in October of 2006 and was caught at the Matter Ranch in late June. She was apparently en route to her winter ground when she was caught near the Coast.

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