Date: 4/25/24 5:12 pm From: Jennifer Outlaw Coulson via groups.io <jenniferocoulson...> Subject: Re: [labird] SEG Environmental Chandeleur Islands Trip 23 April 2024
Wish I had been there!
Off topic, but I noticed that a few photos were uploaded to the wrong
species.
Jennifer Coulson
Pearl River, LA
On Wed, Apr 24, 2024 at 9:01 PM Johnson, Erik via groups.io <Erik.Johnson=
<audubon.org...> wrote:
> LAbird,
>
> I looked up cuckoo continental population estimates in the Partners in
> Flight Database, which is largely based on USGS Breeding Bird Survey data.
> About 8.4 million Yellow-billed Cuckoos in the U.S. and Canada versus about
> 0.9 million Black-billed Cuckoos, or a 10:1 ratio.
> (https://pif.birdconservancy.org/population-estimate-database-scores/)
>
> So why the 100:1 ratio detected in migration per Van (I'm inclined to
> agree with that). Interesting that with a low sample, Robb got more of a
> 10:1 ratio in nocturnal flight - would be interesting to know how that
> stacks up across a season, or multiple seasons.
>
> In the eBird weekly abundance maps, Black-billed Cuckoo all but disappears
> in migration.
>
> https://science.ebird.org/en/status-and-trends/species/bkbcuc/abundance-map-weekly >
> My hunch is that Black-billed Cuckoo is more of a long-distance jumper
> than Yellow-billed Cuckoo, which may be better described as a
> short-distance skipper. The corollary is that Black-billed would pass
> through faster, thus is less available for detection.
>
> An alternative (or contributing factor) is that Black-bills are a lot less
> easy to detect, but I just don't believe that Yellow-billed Cuckoo is 10x
> as likely to be detected as a Black-billed. Black-bills do seem to be a lot
> less vocal, however, so maybe that's some of it.
>
> Someone needs to do a migration tracking study on Black-billed Cuckoos!
> Only 3 Motus tags ever deployed, and no other tracking information seems to
> be published.
>
> Happy migration!
> Erik Johnson
> Sunset, LA
> Erik.Johnson AT Audubon.org
>
>
>
> -----Original Message-----
> From: <labird...> <labird...> On Behalf Of Robb Brumfield via
> groups.io
> Sent: Wednesday, April 24, 2024 8:22 PM
> To: James V Remsen <najames...>; Jack Rogers <jack...>
> Cc: LABIRD <labird...>
> Subject: Re: [labird] SEG Environmental Chandeleur Islands Trip 23 April
> 2024
>
> From my nocturnal flight call station in Baton Rouge the evening of April
> 22nd was a season high for migrating cuckoos. Between 9:30 pm and 3:30 am
> (April 23rd) I had 24 individual yellow-billed and 2 black-billed.
>
> Robb
>
>
>
> Robb T. Brumfield, PhD
> Associate Dean of Research & Administration, College of Science Roy Paul
> Daniels Professor of Biological Sciences Curator of Genetic Resources,
> Museum of Natural Science Louisiana State University | lsu.edu |
> science.lsu.edu/
> office: 225-578-4206|mobile: 225-202-8892|fax: 225-578-8826 <robb...>
> <mailto:<robb...> >
>
>
>
> From: <labird...> <labird...> on behalf of James V Remsen via
> groups.io <najames...>
> Date: Wednesday, April 24, 2024 at 7:49 PM
> To: Jack Rogers <jack...>
> Cc: LABIRD <labird...>
> Subject: Re: [labird] SEG Environmental Chandeleur Islands Trip 23 April
> 2024 Jack et al. — wow, what an experience! Fascinating.
>
> As for the cuckoo prevalence …. Another hypothesis is that it was just one
> of those “cuckoo waves”. Spring waves are often dominated by one taxonomic
> category. For example, sometimes there are “cardinaline days" with
> buntings, grosbeaks, and Dickcissels making up the bulk of the migrants.
> Rarely there are “thrush days, with Catharus species and Wood Thrush
> predominating. Sometimes warblers steal the show. Sometimes Catbirds or
> R-e Vireos are way over-represented.
>
> As fo YB vs. BB cuckoos — indeed it’s pretty clear that YB is a common
> bird with a huge overall population, and BB is generally scarce. Although
> YB has a larger breeding distribution, the difference is small compared to
> the ratio of migrants detected, which I suspect is at least 100:1. Why the
> disparity is so great is a mystery to me and to my buddies with whom I’ve
> discussed this on long birding trips. My personal high count for BB is 5,
> way back in April 1979, and nowadays, seeing more than 1 in day is a big
> deal. There have been years when I’ve not seen one at all.
>
> Van Remsen
>
> ===================
>
> Dr. J. V. Remsen
> Emeritus Prof. of Natural Science and Curator of Birds Museum of Natural
> Science/Dept. Biological Sciences LSU, Baton Rouge, LA 70803
> najames<at>LSU.edu
>
> > On Apr 24, 2024, at 5:01 PM, Jack Rogers via groups.io <jack=
> <4rogers.com...> wrote:
> >
> > [You don't often get email from <jack...> Learn why
> > this is important at https://aka.ms/LearnAboutSenderIdentification ]
> >
> > LaBird
> > I hope you all have been having a birdy spring! Hopefully we get one
> > more front before the end of the month--these south winds have been
> killing me!
> > I wanted to write to talk about the crazy day on the Chandeleurs that
> > we had yesterday. As part of an ongoing survey by SEG Environmental,
> > we bird the island once a month looking to assess the numbers of
> > several target species (Red Knot, Chandeleur Gull, Wilson's/Piping/Snowy
> Plovers, etc.).
> > I think that we have all been most excited for the April survey, and
> > it definitely lived up to expectations.
> >
> > For those that have not had the pleasure of visiting the Chandeleurs,
> > it is an amazing place. Most (I would estimate over 90%) of the
> > island's vegetation is Saltmarsh Cordgrass (Spartina alterniflora); in
> > some of the slightly higher elevation areas, there is also Phragmites
> > and Groundsel as well. Matt Conn and I surveyed the northern tip of
> > Chandeleur Island, which has almost no vegetation except for Spartina.
> > The birding was nothing short of excellent-we had 81 species (+1
> > Chandeleur Gull), which I think is pretty great considering there is
> > only 1 tree in that section (a 6 ft tall Mangrove). There were about
> > 7 small mounds in the saltmarsh that had small groundsel bushes or
> > Phragmites stands. Each bush or stand of Phragmites was astoundingly
> > full of migrants. Take a look at our eBird checklist here
> > <https://ebird.org/checklist/S170012706<https://ebird.org/checklist/S1 > > 70012706>> for the full rundown. My personal highlight was the best
> > Black-billed Cuckoo looks I can ask for! I know several other groups
> > had great birds as well: Cape May Warbler (x2), Yellow Rail (!!), and
> Blackpoll Warblers were seen by other surveyors on their more southerly
> transects.
> >
> > I was most interested by the incredible density of Cuckoos compared to
> > smaller migrants (e.g. warblers, buntings, etc). The only thing I can
> > think of is that there is really nothing for cuckoos to eat on the
> islands:
> > there is no fruit, no insects much larger than saltmarsh moths or
> > horseflies, nothing that Cuckoos could theoretically refuel themselves
> > with after a trans-Gulf flight. Whereas there are plenty of tiny
> > insects (aphids, mosquitos, miniscule beetles and saltmarsh flies) for
> > warblers to eat, and plenty of seeds for INBUs etc. I also found the
> > ratio of Yellow- to Black-billed Cuckoos interesting. I believe that
> > Matt and I had a 100% detection rate of Cuckoos within our section,
> > and am pretty positive in a 100% correct identification rate as well.
> > I have always thought that my lack of mainland BB Cuckoos was a
> > detection error, but now I am wondering if it is more of a disparity in
> population sizes.
> >
> > I wrote this in my eBird comments, but this was really one of the most
> > exciting days of birding in my life. Small groundsel bushes (2 feet
> > high with a diameter of 18 inches) were holding ridiculous totals of
> > birds such as one that held 7 Y-b Cuckoos, 3 Catbirds, 2 Ovenbirds, 1
> > Swainson's Thrush, and 2 Yellow Warblers. An absolutely incredible
> > experience, and just wanted to share that with you all.
> > Thanks for reading this monologue and good birding to y'all, Jack
> > Rogers
> >
> > --
> > Jack Rogers
> > LSU Renewable Natural Resources
> > Baton Rouge, Louisiana/Mt Pleasant, SC My Flickr page
> > <http://www.flickr.com/photos/90726323@N05/<http://www.flickr.com/phot > > os/90726323@N05/>>
> >
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