Monday, May 14, 2018

Bird Island - The Cormorant Saga - Part 1


Bird Island - May 10, 2018 - Point Lobos State Natural Reserve, Monterey County California
The fully accessible trail to Bird Island is a .8 mile round trip.  The views are spectacular - Monterey Pines, an amazing variety of delicate spring wildflowers, white sand coves (above photo), harbor seal moms and pups, and Bird Island, famous for its breeding colony of Brandt’s Cormorant. 
 Brandt’s Cormorant nest in colonies, large congregation of individuals that build their nests in a particular location.  In the above photo Brandt's are clustered together in an oval depression on Bird Island.  When expanding the photo you can see quite a few well established nests. The Brandt have been nesting on Bird Island for many decades.  On the far left of the photo a Brandt's Cormorant can be seen carrying construction material for his nest.  In my opinion the occupied depression is the prime real estate on Bird Island.
The male chooses the nest site.  In the above photo a male is displaying his vivd blue gular pouch with high hopes of attracting a mate.  Males begin nest building before finding a mate.  Nests consist of  seaweed, eelgrass, alga and nearby vegetation.  Unfortunately, while he is off gathering, a rival male may steal some of his nesting material. 

Females move among the advertising males with thin, up-stretched necks.  As a female approaches a group of males (center), there is a sudden increase in displays.

After they pair up, males continue gathering nesting material while the females builds the nest; guano will glue the nest together.  Both the male and female defend their nest site from interlopers.  When a nest exchange is made the eggs are turned by the new sitter.  Incubation (28-31 days) is carried out by both parents.  Care is taken during a nest exchange because Western Gulls are waiting for their chance to snatch an egg or a nestling.  Rarely are eggs left unattended. 
 The Brandt's smaller, slimmer relative, the Pelagic Cormorant, nests near Bird Island on the sheer sides of steep cliffs; they are not as social nor gregarious as the Brant's. (Pelagic Cormorant photo by Mike Baird)  
Their mating displays are similar to their larger cousin, with the addition of wing flapping to show off their beautiful white flanks. 
Once they find a nest site they tend to be faithful to it for the rest of their lives.  Nests become large due to reuse.  They lay 3 - 5 eggs - would love to get a photo of Pelagic Cormorant nestlings crowded into their precariously positioned nest.  Hmm, maybe a return trip is in order for late June.