[Tweeters] Pigeon Guillemot in Breeding Plumage in Early February?

[HAL MICHAEL]

The birds being talked about (Alcids, corms) are piscivores.  I wonder if changes in fish spawning, species compositions, and timing have not made some high quality food available in mid-winter.  

In its native range, the Nene nests in the fall.  It is the only waterfowl to nest on declining day length. But, captive birds here on North America, and probably Europe, nest in spring on an increasing day length. It looked to me like spring bloom in grass growth in the temperate northern hemisphere actually triggered egg production.  The last few decades have seen massive increases in chum and pink slamon fry and conversion from herring to anchovy.  All may be more available now.

Hal Michael
Board of Directors, Ecologists Without Borders http://ecowb.org/
Olympia WA
360-459-4005
360-791-7702 (C)
ucd880 at comcast.net




>     On 02/06/2023 11:55 PM Michael Price <loblollyboy at gmail.com> wrote:

> 

> 

>     Dennis Paulson writes: <Alcids are the only group among our birds that may molt into breeding plumage very early in spring, i.e., mid- to late winter....>

> 

>     With greatest respect, Dennis, not the only group. In the mid-90s, I did personal-interest surveys around the Stanley Park seawall on (weather and work permitting) a daily basis for several years. Of the Pelagic Cormorant (PECO) wintering population at Prospect Point usually numbering about 50-60 birds, about a third would disappear in late November, only to reappear (same birds? if so, average return date over a three year stretch, Jan 19) in full Alternate/Breeding plumage. No idea where they went to complete their pre-alternate molt; but it can't have been far. Because there's no visible sexual dimorphism in PECO, there was no way to tell what age/sex ratios there might have been in that absconding third, and I'm still kinda unsure whether to whether call the returning birds actual migrants.

> 

>     This molt-timing mirrors that of West Coast alcids, and I wouldn't be surprised if it applies to Brandt's Cormorant (BRCO) as well. Would it apply to Double-crested Cormorant (DCCO) (which, god help me, is still think of an eastern species come west) too?

> 

>     best, m

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