[CINC] Cormorants

[Staci Kaye-Carr]

Hi George and fellow CINCers,

Here are some very short videos of cormorants diving.

http://www.youtube.com/watch?v=vDG_e2IgrFc

http://www.youtube.com/watch?v=VHWNx5PcnGU&NR=1

Info and pretty pictures...

Brandt’s Comorant
http://www.birdinginformation.com/birds/comorants/brandts-comorant/
Double-Crested Cormorant
http://www.birdinginformation.com/birds/comorants/double-crested-cormorant/
Pelagic Cormorant
http://www.birdinginformation.com/birds/comorants/pelagic-cormorant/
There are 37 different cormorant species worldwide. (We have 3 species  
we see locally, Brants, Double Crested and Pelagic ) and they vary in  
how long and deep they can dive. (Brants, 150 ft., Double Crested 40  
ft and Pelagic 180 ft.)  They have oil interwoven in their feathers  
that make them less buoyant than other birds and they swallow stones,  
which are lodged in their gut and act like a scuba diver's weight belt.

Cormorants are waterbirds, whose name means "crows of the sea." A  
member of the pelican family, they can fly at speeds of 50 mph and are  
particularly adept at swimming underwater, which is why they are such  
skilled fish catchers. They feed mostly on fish but also feed on  
crustaceans, frogs, tadpoles and insect larvae.
They live mainly in tropical and temperate areas but have been found  
in polar waters. Some are solely saltwater birds. Some are solely  
freshwater birds. Some are both. Some nest in trees. Others nest on  
rock islands or cliff edges.  In the wild they form some of the  
densest colonies of birds known. (There is a large nesting colony in  
the cliff face at the Landing Cove at Anacapa Island) The eggs are a  
chalky-blue color. There is usually one brood a year. The young are  
fed through regurgitation.  Cormorants form same sex partnerships when  
they can not find opposite sex partners.

Their guano is collected and used as fertilizer.

Unlike most water birds, which have water resistant feathers,  
cormorants have feathers that are designed to get throughly wet Their  
feathers don't trap air like water resistant varieties. This make it  
easier for them to dive and stay submerged while they chase fish. But  
this also means that their feathers become waterlogged. After spending  
time in the water cormorants spend considerable time on shore drying  
out. When they are out of the water they stretch out their wings to  
dry their feathers.

Cormorant pursue fish underwater with their eyes open, their wings  
pressed against their bodies, kicking furiously with their legs and  
feet at the back end of their bodies. It swims underwater with its  
wings folded along its body, and thrusting its webbed feet which  
provides enough propulsion for a cormorant to tailgate a fish and  
catch it crosswise on its hooked bill. The cormorant generally brings  
a fish to surface after 10 to 20 seconds and flips it in the air to  
position it correctly and smooth down its spines.”

Cormorants swallow fish whole and head first. They usually take a  
little time to shift the fish around to get it to go down their throat  
the right way. Bones and other indigestible parts are regurgitated in  
a nasty goo. In the Brazilian Amazon, cormorants have been observed  
working as a team, splashing the water with their wings and driving  
fish into shallow water near the shore where they are easily collected.

I hope this helps and welcome to the Naturalist Corps!

Staci Kaye-Carr



On May 27, 2011, at 2:33 PM, George Moore wrote:

> Question: How deep can Cormorants dive? According to Sibley,  
> Pelagics can dive down to 150'.
> George Moore CINC volunteer
>
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