Friends of Salter Grove logo
Menu

Double-crested Cormorant

Phalacrocorax auritus
Phalacrocoracidae

Usually just a dark silhouette at Salter Grove
Unusual eye color, orange face patch, hooked bill
Scaly feathers for a prehistoric look
Snake-like neck and large webbed feet
Commutes frequently between North and South Coves when present at Salter Grove
Body low in water, beak upturned
Poorly-oiled feathers drenched after dives
50% of day spent resting and drying out
Double crests appear for breeding
Pair in full breeding headdress
Trees holding nests eventually die from accumulation of guano from colony of cormorants
Clutch 1 to 7 eggs, usually 4; both parents incubate
Newly hatched birds can barely move heads
Both parents regurgitate food for young
Juvenile drying raggedy-looking plumage
Juveniles fly 6 weeks after hatching
Juveniles dive at 7 weeks
Fish bigger than juvenile gullet?
Juvenile independent from adult after 10 weeks
Immatures breed after two years
A mix-aged flotilla in migration

At Salter Grove, the prehistoric-looking Double-crested Cormorant is present in both North and South Coves from late April through November.  The cormorants observed have dark adult plumage but probably are less than five years-old, the age when breeding begins.  There is no evidence that cormorants breed in the park.

During their residency, a few to several dozens cormorants can be seen busily diving for fish, or flying back and forth between the boat moorings in North Cove and the rocky islets south of Rock Island. 

Cormorants have less preen oil than other waterbirds and at low tide on a sunny day, exposed rocks are densely covered by cormorants holding up half-spread wings to dry.  Peak numbers occur in October, when hundreds of mostly black post-breeding adults and grayish brown juveniles gather into large flotillas before leaving the park.

The Double-crested Cormorant is widespread across North America near rivers and lakes as well as in coastal areas.  It ranges as far north as Southern Alaska and as far south as northwestern Mexico.

They are colonial nesters and will reuse a favorable stand of trees year after year.  Over time however, the accumulation of excrement alter soil conditions and kills the trees.  The cormorants have to either find a new site or nest on the ground where they would be prone to mammalian predators like coyotes, foxes, raccoons.

Like the Bald Eagle, the Double-crested Cormorant also suffered a steep population decline during the 1960's because the DDT they accumulated through the fish consumed resulted in eggs with very thin shells.  They have recovered so well since the 1970's that the U.S. Fish and Wildlife Service now issues permits to cull nesting colonies where they are thought to be crowding out other colonial water birds like herons, or where they are adversely affecting fisheries.