Re: "Juvenile cowbirds sneak out at night" - RE: [cayugabirds-l] Cowbirds

2020-04-12 Thread Dave Nutter
Thanks, Anne, for clearing that up. It’s much less bizarre that the fledglings, 
after being old enough fly well, move out of the host territory at dusk to 
roost, but still fascinating because it’s not clear why they should leave if 
they are only going back again in the morning. Maybe they don’t know the 
boundaries, or maybe it’s a bit of exploration, seeking out places where they 
might feed on their own later on. When they return by day to the host 
territory, do they continue to be fed by the hosts?

- - Dave Nutter

> On Apr 12, 2020, at 10:14 AM, AB Clark  wrote:
>  the FLEDGLINGS (juveniles that have left the nest and are flying, at about 
> 10-20 days old) are often leaving on their own, at dusk, to ROOST (sit in the 
> dark) away from their foster-parents territories, but still returning to 
> those territories in daytime.
> 

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Re: "Juvenile cowbirds sneak out at night" - RE: [cayugabirds-l] Cowbirds

2020-04-12 Thread Regi Teasley
“Young Cowbirds won’t you come out tonight? Come out tonight? Come out 
tonight
And dance by the light of the moon.” 


Those who dwell among the beauties and mysteries of the earth are never alone 
or weary of life.  Rachel Carson.


> On Apr 12, 2020, at 4:47 PM, Magnus Fiskesjo  
> wrote:
> 
> 
> Thanks! Yes Indeed it seems that in the 2015 study, cowbird youngsters 
> (*fledglings*) were *spending the night away* from their slave parents and 
> then return *not* to the *nest* but to the foster parents' location -- for 
> more slave feeding. This scenario does make more sense, yes, so it may well 
> be I misremembered about the *nest* part. The *fledglings* going out on their 
> own would also resolve, perhaps, John Confer's points of doubt about body 
> temperature. 
> 
> But note, that we are not up to date, yet -- the 2015 publication was 
> apparently superseded by new research which expanded, to discover the 
> "teenager party" as reported in Living Bird, I believe some time in 2017-2019 
> -- that is, about young cowbirds *not* sitting in the dark (which makes 
> little or no sense, to me, at least! why would they do that?), but hanging 
> out with young cowbird peers which would enable them to build cowbirdness. To 
> me it looks like this additional discovery was not yet made in 2015 -- so in 
> that study they mistakenly concluded that the young cowbird was sitting alone 
> in the dark, instead of going to his peer party. 
> 
> If I do find it again, I'll forward it. 
> 
> --If anyone on this list has a digital copy already, please post a copy. 
> 
> Many thanks again, over and out for now, 
> Magnus
> --
> Magnus Fiskesjö, PhD
> Associate Professor, Department of Anthropology, Cornell University
> McGraw Hall, Room 201. Ithaca, NY 14853, USA
> E-mail: magnus.fiske...@cornell.edu, or: n...@cornell.edu
> 
> From: AB Clark [anneb.cl...@gmail.com]
> Sent: Sunday, April 12, 2020 10:14 AM
> To: Magnus Fiskesjo
> Cc: John Confer; CAYUGABIRDS-L
> Subject: Re: "Juvenile cowbirds sneak out at night" - RE: [cayugabirds-l] 
> Cowbirds
> 
> At the risk of making this a longer-than-wanted discussion, I will briefly 
> answer—and then retreat!
> 
> I just read Magnus’  report on Louder et al’s study from U Illinois and 
> downloaded the actual paper and here is the story.  No one is leaving at 3 
> am!  Or flying out of a nest as a nestling.  Too much fine grained 
> terminology is leading to misunderstandings, but it is a fascinating paper.
> 
> SO—the question that the researchers were interested in was whether actual 
> biological mothers of young cowbirds were somehow leading their own 
> fledglings away from the Host-parents territory.  The answer is NO.  But the 
> FLEDGLINGS (juveniles that have left the nest and are flying, at about 10-20 
> days old) are often leaving on their own, at dusk, to ROOST (sit in the dark) 
> away from their foster-parents territories, but still returning to those 
> territories in daytime.
> 
> The confusions come in because they put the little radios on the cowbird 
> young on about the last day when they were still in their host-nests as 
> NESTLINGS, but the observations they report were all on FLEDGLINGS, young 
> that had left their nests, never to return.  In Icterids, nestlings do not 
> leave flighted, but they can flutter and can cling and climb with strong well 
> developed legs.  From what I remember, young cowbirds develop a little faster 
> than some.  So maybe they fly as early as 5-6 days after fledging—I have to 
> check.
> 
> But it is during the later FLEDGLING stage, out of the nests and mobile, that 
> they start to disappear off foster-territory in the evening.  Sunset isn’t 
> dark, so they can still move easily;  apparently motivated by whatever gets a 
> cowbird to become a cowbird, they often left to roost alone, during the next 
> 3 weeks of still being associated with foster-parents during the day.  And 
> their non-doting cowbird mothers don’t have anything to do with it, because 
> they were also being tracked by radios and triangulating receiver towers, and 
> mom-cowbirds were not present during these movements.
> 
> Did it bring juvenile cowbirds into contact with other cowbirds?  Apparently 
> not, at that stage.  But the “go away, young man/cowbird” urge was already 
> present.
> 
> 
> So thanks, Magnus, for bringing our attention to this really interesting 
> report!  (I can send it to anyone who wants to read it!)
> 
> Anne
> 
> Anne B Clark
> 147 Hile School Rd
> Freeville, NY 13068
> 607-222-0905
> anneb.cl...@gmail.com<mailto:anneb.cl...@gmail.com>
> 
> 
> 
> On Apr 11, 

RE: "Juvenile cowbirds sneak out at night" - RE: [cayugabirds-l] Cowbirds

2020-04-12 Thread Magnus Fiskesjo


Thanks! Yes Indeed it seems that in the 2015 study, cowbird youngsters 
(*fledglings*) were *spending the night away* from their slave parents and then 
return *not* to the *nest* but to the foster parents' location -- for more 
slave feeding. This scenario does make more sense, yes, so it may well be I 
misremembered about the *nest* part. The *fledglings* going out on their own 
would also resolve, perhaps, John Confer's points of doubt about body 
temperature. 

But note, that we are not up to date, yet -- the 2015 publication was 
apparently superseded by new research which expanded, to discover the "teenager 
party" as reported in Living Bird, I believe some time in 2017-2019 -- that is, 
about young cowbirds *not* sitting in the dark (which makes little or no sense, 
to me, at least! why would they do that?), but hanging out with young cowbird 
peers which would enable them to build cowbirdness. To me it looks like this 
additional discovery was not yet made in 2015 -- so in that study they 
mistakenly concluded that the young cowbird was sitting alone in the dark, 
instead of going to his peer party. 

If I do find it again, I'll forward it. 

--If anyone on this list has a digital copy already, please post a copy. 

Many thanks again, over and out for now, 
Magnus
--
Magnus Fiskesjö, PhD
Associate Professor, Department of Anthropology, Cornell University
McGraw Hall, Room 201. Ithaca, NY 14853, USA
E-mail: magnus.fiske...@cornell.edu, or: n...@cornell.edu

From: AB Clark [anneb.cl...@gmail.com]
Sent: Sunday, April 12, 2020 10:14 AM
To: Magnus Fiskesjo
Cc: John Confer; CAYUGABIRDS-L
Subject: Re: "Juvenile cowbirds sneak out at night" - RE: [cayugabirds-l] 
Cowbirds

At the risk of making this a longer-than-wanted discussion, I will briefly 
answer—and then retreat!

 I just read Magnus’  report on Louder et al’s study from U Illinois and 
downloaded the actual paper and here is the story.  No one is leaving at 3 am!  
Or flying out of a nest as a nestling.  Too much fine grained terminology is 
leading to misunderstandings, but it is a fascinating paper.

SO—the question that the researchers were interested in was whether actual 
biological mothers of young cowbirds were somehow leading their own fledglings 
away from the Host-parents territory.  The answer is NO.  But the FLEDGLINGS 
(juveniles that have left the nest and are flying, at about 10-20 days old) are 
often leaving on their own, at dusk, to ROOST (sit in the dark) away from their 
foster-parents territories, but still returning to those territories in daytime.

The confusions come in because they put the little radios on the cowbird young 
on about the last day when they were still in their host-nests as NESTLINGS, 
but the observations they report were all on FLEDGLINGS, young that had left 
their nests, never to return.  In Icterids, nestlings do not leave flighted, 
but they can flutter and can cling and climb with strong well developed legs.  
From what I remember, young cowbirds develop a little faster than some.  So 
maybe they fly as early as 5-6 days after fledging—I have to check.

 But it is during the later FLEDGLING stage, out of the nests and mobile, that 
they start to disappear off foster-territory in the evening.  Sunset isn’t 
dark, so they can still move easily;  apparently motivated by whatever gets a 
cowbird to become a cowbird, they often left to roost alone, during the next 3 
weeks of still being associated with foster-parents during the day.  And their 
non-doting cowbird mothers don’t have anything to do with it, because they were 
also being tracked by radios and triangulating receiver towers, and 
mom-cowbirds were not present during these movements.

Did it bring juvenile cowbirds into contact with other cowbirds?  Apparently 
not, at that stage.  But the “go away, young man/cowbird” urge was already 
present.


So thanks, Magnus, for bringing our attention to this really interesting 
report!  (I can send it to anyone who wants to read it!)

Anne

Anne B Clark
147 Hile School Rd
Freeville, NY 13068
607-222-0905
anneb.cl...@gmail.com<mailto:anneb.cl...@gmail.com>



On Apr 11, 2020, at 10:02 PM, Magnus Fiskesjo 
mailto:magnus.fiske...@cornell.edu>> wrote:


Thanks. Yes it's curious and hard-to-believe and I think that's why I remember 
so clearly reading about this in the Lab of O's Living Bird member's magazine, 
but as I said, can't find that article online--perhaps it is only in their 
printed version which I must have read 2017 or later. AllAboutBird account is 
much earlier, 2009, and does not bring up what must be some NEW research ( 
https://www.allaboutbirds.org/news/if-brown-headed-cowbirds-are-reared-by-other-species-how-do-they-know-they-are-cowbirds-when-they-grow-up/
 ).

Regardless, just now a friend sent me this 2015 report below, which mentions 
the SAME strange observations that I believe I read in Living Bird -- with

Re: "Juvenile cowbirds sneak out at night" - RE: [cayugabirds-l] Cowbirds

2020-04-12 Thread AB Clark
At the risk of making this a longer-than-wanted discussion, I will briefly 
answer—and then retreat!

 I just read Magnus’  report on Louder et al’s study from U Illinois and 
downloaded the actual paper and here is the story.  No one is leaving at 3 am!  
Or flying out of a nest as a nestling.  Too much fine grained terminology is 
leading to misunderstandings, but it is a fascinating paper.

SO—the question that the researchers were interested in was whether actual 
biological mothers of young cowbirds were somehow leading their own fledglings 
away from the Host-parents territory.  The answer is NO.  But the FLEDGLINGS 
(juveniles that have left the nest and are flying, at about 10-20 days old) are 
often leaving on their own, at dusk, to ROOST (sit in the dark) away from their 
foster-parents territories, but still returning to those territories in daytime.

The confusions come in because they put the little radios on the cowbird young 
on about the last day when they were still in their host-nests as NESTLINGS, 
but the observations they report were all on FLEDGLINGS, young that had left 
their nests, never to return.  In Icterids, nestlings do not leave flighted, 
but they can flutter and can cling and climb with strong well developed legs.  
From what I remember, young cowbirds develop a little faster than some.  So 
maybe they fly as early as 5-6 days after fledging—I have to check. 

 But it is during the later FLEDGLING stage, out of the nests and mobile, that 
they start to disappear off foster-territory in the evening.  Sunset isn’t 
dark, so they can still move easily;  apparently motivated by whatever gets a 
cowbird to become a cowbird, they often left to roost alone, during the next 3 
weeks of still being associated with foster-parents during the day.  And their 
non-doting cowbird mothers don’t have anything to do with it, because they were 
also being tracked by radios and triangulating receiver towers, and 
mom-cowbirds were not present during these movements.

Did it bring juvenile cowbirds into contact with other cowbirds?  Apparently 
not, at that stage.  But the “go away, young man/cowbird” urge was already 
present.  


So thanks, Magnus, for bringing our attention to this really interesting 
report!  (I can send it to anyone who wants to read it!)

Anne

Anne B Clark
147 Hile School Rd
Freeville, NY 13068
607-222-0905
anneb.cl...@gmail.com



> On Apr 11, 2020, at 10:02 PM, Magnus Fiskesjo  
> wrote:
> 
> 
> Thanks. Yes it's curious and hard-to-believe and I think that's why I 
> remember so clearly reading about this in the Lab of O's Living Bird member's 
> magazine, but as I said, can't find that article online--perhaps it is only 
> in their printed version which I must have read 2017 or later. AllAboutBird 
> account is much earlier, 2009, and does not bring up what must be some NEW 
> research ( 
> https://www.allaboutbirds.org/news/if-brown-headed-cowbirds-are-reared-by-other-species-how-do-they-know-they-are-cowbirds-when-they-grow-up/
>  ).
> 
> Regardless, just now a friend sent me this 2015 report below, which mentions 
> the SAME strange observations that I believe I read in Living Bird -- with 
> minor differences: this report mentions chicks as nightly departing foster 
> nests after sunset, not 3am, BUT returning only at dawn; also, it says the 
> nightly escape is solitary, NOT to congregate with other young cowbirds in a 
> 'teenager party' as I remember from Living Bird (which also said that the 
> field congregation was only revealed to Science after new tracking that was 
> launched only once researchers had found that the cowbird chick they 
> monitored was missing from its nest at night! So, maybe the 'teenager party' 
> was only found out after simultaneously tracking several youngsters?)  
> 
> Anyhow, here goes:
> 
> https://www.sciencedaily.com/releases/2015/11/151102152607.htm
> 
> Science News
> 
> Juvenile cowbirds sneak out at night
> Date:November 2, 2015
> Source:University of Illinois at Urbana-Champaign
> 
> A new study explores how a young cowbird, left as an egg in the nest of a 
> different species, grows up to know it's a cowbird and not a warbler, thrush 
> or sparrow.
> 
> The study, published in Animal Behaviour, reveals that cowbird juveniles 
> leave the host parents at dusk and spend their nights in nearby fields, 
> returning just after daybreak. This behavior likely plays a role in the 
> cowbirds' ability to avoid imprinting on their host parents.
> 
> "If I took a chickadee and I put it in a titmouse nest, the chickadee would 
> start learning the song of the titmouse and it would actually learn the 
> titmouse behaviors," said Matthew Louder, who conducted the study as a Ph.D. 
> student with Illinois Natural History Survey avian ecologist Jeff Hoover and 
> INHS biological surveys coordinator Wendy Schelsky. "And then, when it was 
> old enough, the chickadee would prefer to mate with the titmouse, which would 
> be an