Wednesday, March 9, 2011

Winter Sampling at BCCER - March 7, 2011

On this winter night we set up our station at OWL3 at the BCCER. Past years have suggested that spring migration to the summering grounds occurs in early March when we have captured several owls in one setting. On this night serenaded by a great horned owl and numerous flocks of snow geese flying overhead, we captured three owls, but only one of these was unbanded. The other two owls had been captured three times previously, making this their fourth capture, an uncommon event. Our recapture rate is low and this is attributed to the birds being "net savvy;" once a bird is captured they rarely go back to the same site during the same season. These two owls seem to be "net happy," due to the high number of times they have been captured in the same season. It tells me that the audiolure is extremely attractive to some owls!

Here is their story.

Both birds were banded on October 15, 2010 during fall migration at the OWL3 site at BCCER. They are identified as band number 1014-14523 and 1014-14524, and although their band numbers are sequential, they were banded at different times that night. Each was captured on different nights two more times until March 7, 2011, when they were captured together again- this time during the same net run time. The number of days between capture is 149 days -close to 5 months, which is great evidence that the BCCER provides fine wintering habitat for these owls. Other research has suggested that siblings may travel together during migration, and although we can't say for sure, these birds could be siblings, based on the their capture patterns, see below.

Capture Date / Mass in grams / Sex (based on wing chord length and mass)
1014-14523
10/15/2010 84.3 unknown
11/1/2010 98.9 female
1/27/2011 84.9 unknown
3/07/ 2011 86.9 unknown

1014-14524
10/15/2010 95.4 female
10/16/2010 90.4 female
11/3/2010 97.2 female
3/07/ 201 93 female

2 comments:

  1. the one on the left is frowning at her situation.
    : )
    - The Equestrian Vagabond

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  2. yeah, she's kinda pissed at being caught 4 times!

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