You know what I'm going to say. I suspect much of this is about food. Animals depend on plants. Plants suffered late freezes in spring 2020 (no fruit or seed set for most woody plants), an early hard freeze last September immediately on the heels of days with high temps near 100, and then threw their spring development into reverse back in mid-Feb when it hit -20 to in excess of -30 in some places. Insects no doubt suffered directly or are waiting for the plants just like we're waiting for the warblers. Most of the neotrops we long for eat insects. Add to that the fact the eastern plains is into the second decade of a drought. Can you imagine a bird that is coming north looking at what western MX and TX and NM look like and deciding to just fly north for hundreds and hundreds of miles thru more of the same? The definition of insanity describes that, and most birds aren't insane. Humans, maybe, but not birds. Maybe more birds are diverting up the west side of the Divide, or maybe more are going right up the spine. I suspect the answer is a combination of waiting, doing the two things I just mentioned and just plain fewer individual birds. If there was major mortality during fall migration, the number of survivors certainly didn't increase during months of wintering and the inherent perils of early spring migration. Just my guesses. Our job is to observe, enjoy and document what happens next.
Dave Leatherman Fort Collins ________________________________ From: [email protected] <[email protected]> on behalf of Diana Beatty <[email protected]> Sent: Friday, April 16, 2021 6:35 AM To: Paula Hansley <[email protected]> Cc: CObirds <[email protected]> Subject: Re: [cobirds] Passerine migration ? FWIW, I keep a little book recording dates of things blooming in my yard, weather, bird sightings, etc., and in general the dates for things this thing are about 10-14 days behind some other years - spring is just later in my yard in this year than some other years. Denver just recorded its second-snowiest March on record this year and in my records, there have been fewer really spring-like days by quite a bit so far this year than some in the recent past. I don't know if any of that is the reason, but just an observation. Diana Beatty El Paso County On Fri, Apr 16, 2021 at 5:34 AM Paula Hansley <[email protected]<mailto:[email protected]>> wrote: I second David’s comment/question about why is passerine migration being late. I have yet to see a Ruby-crowned Kinglet or Yellow-rumped Warbler. Paula Hansley Sent from my iPhone -- -- 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]<mailto:[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]<mailto:cobirds%[email protected]>. To view this discussion on the web visit https://groups.google.com/d/msgid/cobirds/FC25934C-A1F2-461D-AACF-3EE240415DC5%40gmail.com. -- ****** All that is gold does not glitter, not all those who wander are lost; the old that is strong does not wither, deep roots are not reached by the frost. -- -- 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]<mailto:[email protected]>. To view this discussion on the web visit https://groups.google.com/d/msgid/cobirds/CAM-_j9tA-J3ziygnsycgiM1FXx--kFe0cSCqprtQvw%2BY_ET8aQ%40mail.gmail.com<https://groups.google.com/d/msgid/cobirds/CAM-_j9tA-J3ziygnsycgiM1FXx--kFe0cSCqprtQvw%2BY_ET8aQ%40mail.gmail.com?utm_medium=email&utm_source=footer>. -- -- 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/CY4PR0601MB376361E3006DCB56A3276F37C14C9%40CY4PR0601MB3763.namprd06.prod.outlook.com.
