Hey COBirders,
Not big numbers, but more migrants arrived early this morning. There were noticeable small birds moving around, unlike all other days so far. Best: 5 Yellow Warblers, including 2 FOY females Com Yellowthroat, plus FOY female FOY Ad M Yellow-breasted Chat FOY Ad M Bullock’s Oriole very few sparrows seen today. Maybe the White-crowneds finally vacated. 25 birds banded Thursday, 15 Friday. A Banding Story….Besides banding passerines to see migrant numbers and diversity, I also am interested in Site Fidelity. Several of the species I band at Clear Spring Ranch do nest here, and I can catch them both in spring when they arrive, and sometimes in August/September before they depart again. I have many individuals that have been seen spring and fall over several years! One female Yellow Warbler today was banded 5/8/2019 as a second year bird (hatched in 2018). I recaptured her 5/20/20, and today, 5/7/21. I have not seen her in the fall yet, so I am not sure if she is nesting here, or further north somewhere, and just passes through CSR. More to be learned! In his new book, Sibley suggests that about 1/2 of each age class will die each year. (so while species may “mate for life” there is a real good chance their mate will change several times.) If she hatched in 2018, 1/2 of her age class was gone by spring 2019, 1/2 again by 2020 (1/4), and 1/2 again by 2021. So she may be part of 1/8 of the survivors in her age class, after just a few years. Nevertheless, assuming she hatched nearby, she has migrated successfully at least six trips so far, and that’s pretty cool. Have a good weekend, Steve Brown Colo Spgs -- -- You received this message because you are subscribed to the Google Groups "Colorado Birds" group. To post to this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/cobirds?hl=en?hl=en * All posts should be signed with the poster's full name and city. Include bird species and location in the subject line when appropriate * Join Colorado Field Ornithologists https://cobirds.org/CFO/Membership/ --- You received this message because you are subscribed to the Google Groups "Colorado Birds" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/cobirds/B1E66579-8A6A-43A0-976A-85B5608929D7%40gmail.com.
