The Conner Museum (WSU) doesn't have many cormorants, but here are their
weights (all in grams). I also included the length and wingspan, if
available, in mm.

Pelagic, all from Washington
736 (sex unknown, I'm looking at the data from home, so I can't look at the
specimen, but this one is probably a youngster)
1725, male
1585, male
1100, male
1450, female
1625, female
1392, female, length (L) 673 mm, wingspan (WS) 973 mm
1362, female, L-644, WS- 889
1844, male, L- 702, WS- 943
1674, male, L 698, WS-949
1349 female, L-669, WS-972
1295 female, L-675, WS-991
1701 male, L-721, WS-1031

Double-crested, Washington
2649, male, L-884, WS-1300
2073, female, L-804, WS-1223
2430, male, L-882, WS-1360
2239, female, L-809, WS-1230
--, male, L-855
2600, male, L-880, WS-1309
2113, male, L-858, WS-1260
1641, female, L-779, WS-1098
1639, female, L-808, WS-1138
Double-crested, Alabama
--, female, L-771, WS-1182
Double-crested, Bear Lake, Idaho
586, female (juv), L-386, WS-442

Pelagic, Average Washington male: 1604 g, stdev 261 g, N = 6
Pelagic, Average Washington female, 1412 g, stdev 116, N= 6

Double-crested, average, Washington male, 2448 g, stdev 242 g, N= 4
Double-crested, average, Washington female, 1898 g, stdev 305 g, N = 4

Our sample of Pelagics from Washington has a lower weight than Dunnings
sample, but both samples are small. Museum samples might be biased in favor
of animals that starved to death (since many museum specimens are picked up
dead and the label doesn't always indicate whether they were salvaged or
shot)

However, if that was true of the Pelagics, it does not seem to have been the
case for Double-crested. Every one of our samples, except the juvie, are
heavier than Dunning's mean for Double-crested.

The body lengths and wingspans of the Double-cresteds in our sample were
also larger than those of the Pelagics.

Kelly Cassidy


> -----Original Message-----
> From: tweeters-bounces at mailman1.u.washington.edu
> [mailto:tweeters-bounces at mailman1.u.washington.edu] On Behalf
> Of James R. Karr
> Sent: Tuesday, April 17, 2007 6:57 PM
> To: Gary Bletsch
> Cc: Tweeters at u.washington.edu
> Subject: Re: [Tweeters] Sibley guide mistake
>
> According to Dunning (CRC Handbook of Avian Body Masses)
>
>
> pelagic cormorant: 9 males average 2034 gms; 5 females
> average 1702 gms
>
> double-crested cormorant: 33 males, 1808 gms; 32 females, 1540 gms
>
>
>
> Jim Karr
>
>
>
> Gary Bletsch wrote:
> > Dear Tweeters,
> >
> > Not knowing anything about "The Onion," I'd say the fellow
> who wrote
> > the Sibley-junco blurb was aiming for satire, or perhaps
> just humor,
> > but has missed his mark.
> >
> > However, there is one thing in the Sibley field guide that
> seems wrong
> > to me, or at least extremely surprising. I believe that the
> weight of
> > the Pelagic Cormorant is listed in the book as being
> greater than that
> > of a Double-crested. For nearly a year now, I have been staring at
> > cormorants--on pilings, in the water, and in the air. I
> have tried in
> > vain to see where a Pelagic could possibly hide some extra flab. I
> > just don't see how such a pencil-necked bird could outweigh a
> > Double-crested.
> >
> > Have I missed something here?
> >
> >
> > Yours truly,
> >
> > Gary Bletsch
> >
> > near Lyman (Skagit County), Washington
> >
> > garybletsch at yahoo.com
> >
> >
> > __________________________________________________
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> >
>
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