Observers: Mary & Nick Freeman
Email: mnfreemanatearthlink.net
Date: 04/24/2007
Time: 12:55 AM -0400
Hi birders. Last week I posted our LAAS field trip observations of our Owens Valley trip, 4/14-15/07. I said I'd post information on the banded Swainson's. Pete Bloom and his crew passed along this very interesting response. I edited it and shortened it some and ran it together it's fascinating news on the banded and radio equipped SWHA we saw last week. Enjoy! Here it is:
"The silver and color band were placed on the SWHA in 1999, the transmitter in 2005. There are approximately one dozen pair of SWHAs that nest annually in the Owens Valley. Some day we hope to write a report on the whole population in the Owens Valley as we've studied it in the past decade or more, including the migration information. The population is relatively small, a dozen or so active territories annually, but very interesting in its habitat relationships, only nesting in small to large trees near alfalfa fields, and using them as their primary hunting sites. Thanks for reporting this sighting!! All the tagged SWHA from the Owens Valley eventually ended up in Argentina. They took different rather interesting routes to get there, though. We never put on a 3-digit color band on a SWHA, so the number is 34. If it was 34, the bird you saw was the male of a pair. There was a female with a 34 but she would not have had a transmitter. The pair was originally banded in July of 1999 as a nesting adult pair. The transmitter was placed on the bird in Aug. of 2005 and is still transmitting. This bird is a [summer] breeding resident (March thru September) of Owens Valley, not one migrating through. It most likely has been commuting to Argentina each year. It is a male and weighed 630 grams when we banded it in July of 1999 - the transmitter was attached in August 2005. The female by Bishop with the silver band was hatched down by Big Pine 3 years ago. She is our first confirmed juvenile returned to nest in the valley. Her first nesting attempt at that location was in 2005 and as far as we can tell it was unsuccessful. She replaced a banded female who had nested on that territory successfully for several years. We were never successful in banding male so we do not know if it is the same male or not. Hopefully she has been successful the last two years."