Re: [cayugabirds-l] Pochard?

[Wesley M. Hochachka]

Hi all,

   I have been doing a little bit of reading about Red-crested Pochards in 
Europe, and it seems that they have histories of both: (1) natural colonization 
based on long-distance mass movement, and (2) becoming established due to 
introductions.  According to the text in the second European Breeding Bird 
Atlas, the species did not live in Europe until the 1800s, with speculation 
that they became established mostly in Spain following severe drought and 
dispersal from the core of their range in Central Asia.  The speculation 
continues that the species then moved northward and eastward into central 
Europe from Spain.  The European and Central Asian populations have been shown 
to now be genetically distinct.  Also, the move northward out of Spain really 
began in earnest in the 1980s, again at a time of drought (this time in Spain). 
 So, these birds do seem to be capable of large-scale vagrancy/establishment.
   However, the British population is considered feral (they are more than a 
regular vagrant in the U.K., but local breeders in the south and east of 
England) according to the most recent British and European breeding bird 
atlases.  The species first appeared in the U.K. in 1937, outside of the period 
of natural range expansion.  Even vagrancy of continental birds from the 
European continent would not require much travel, because the species has been 
established in the Netherlands for a long time (I vaguely remember speculation 
in the 1980s as to whether the birds in the Netherlands were natural dispersers 
or introduced).

   Based on what I've seen of Red-crested Pochards in Germany and Switzerland, 
Cayuga Lake is the sort of place that a Red-crested Pochard would want to live 
in the winter: they winter in similar, large lakes in central Europe.  However, 
hanging out with Redheads may not be entirely within the pochard's comfort 
zone, because I typically have seen them closer to shore, especially when 
feeding making short-duration dives.  However, these pochards are sociable 
outside of the nesting season, I think, because I cannot recall ever seeing a 
single Red-crested Pochard by itself...although the largest cohesive groups 
that I have seen have only been of 10-20 birds.  Oh, and the aforementioned 
European bird atlas describes their food as larger underwater plants of the 
family Characeae.

   Oh, and here's a little back story on the way that eBird is now treating 
reports of birds like this Red-crested Pochard.  The underlying motivation is 
to collect data on species before they become established in a new region.  
Many birders would not report species that the birding community did not 
consider to be established and "countable", because these exotic species would 
be contaminating said birders' eBird-reported life lists.  The desire to keep a 
"pure" life list would mean that species that were in the process of becoming 
established would be under-reported into the eBird database by the birding 
community as a whole.  This led to the very recent changes to eBird's outputs 
in which any species not regionally recognized as established is being treated 
separately in various ways.  For details, here's the URL of the webpage that 
introduces these changes: 
https://ebird.org/news/important-changes-to-exotic-species-in-ebird

Wesley




From: bounce-127060160-3494...@list.cornell.edu 
 on behalf of Dave Nutter 

Sent: Friday, December 30, 2022 21:56
To: Kenneth V. Rosenberg 
Cc: Kevin J. McGowan ; Laura Stenzler ; 
CAYUGABIRDS-L ; Suan Hsi-Yong b 

Subject: Re: [cayugabirds-l] Pochard?

On the basis of Ken’s thoughtful observation that this individual’s behavior - 
traveling with an active flock of migrants - supports it also being a wild 
migrant, and to ensure that this record is noted as perhaps the first such 
instance here, I’m going to add it to the Cayuga Lake Basin First Records List.

- - Dave Nutter

On Dec 30, 2022, at 7:45 PM, Kenneth V. Rosenberg 
mailto:k...@cornell.edu>> wrote:


Just to stir the pot on this one, I’ll point out that (1) Red-crested Pochard 
is a migratory species in Europe and a regular vagrant to Great Britain, (2) 
This past couple of months we have seen a large influx of European vagrants in 
northeastern North America (N. Lapwings, an immature Common Shelduck, even a 
Eurasian Blackbird), and (3) I remember in the 1960s when Tufted Ducks in the 
U.S. were thought to be escapes (before there were enough records to establish 
a pattern of natural occurrence).



I would speculate that the chances of a female Red-crested Pochard in a flock 
of wild and highly mobile Redhead being an “escape” from captivity is close to 
zero.



Ken



Ken Rosenberg (he/him/his)

Applied Conservation Scientist, Retired

Cornell Lab of Ornithology

k...@cornell.edu

Cell: 607-342-4594





From: 

Re: [cayugabirds-l] Pochard?

[Geo Kloppel]

Just received the Murray McMurray Hatchery catalog. This discussion prompted me 
to look there and elsewhere for the availability of Red Crested Pochard 
Hatchlings. Turns out they are offered by lots of hatcheries, though at $150 - 
$300 per pair, they’re aimed at bird fanciers rather than common barnyards.

-Geo

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