Cormorants corvus marinus - sea crow

Systematics Order - Pelecaniformes Order - Pelecaniformes –Suborder - Pelecani Family - Phalacrocoracidae Family - Phalacrocoracidae Subfamilies Subfamilies –Phalacrocoracinae - Cormorants  robust bills  stocky bodies  breed in colonies near lakes or rivers –Leucocarboninae - Shags  longer, slender bills, heads and bodies  never far from marine habitats and rocky shores

General Characteristics Large, blackish water birds Large, blackish water birds long, hooked bill long, hooked bill long tail and long, thin neck long tail and long, thin neck colorful gular pouches and face skin colorful gular pouches and face skin usually have green eyes usually have green eyes sexes alike sexes alike Common sight: Wings stretched to dry them while standing erect Common sight: Wings stretched to dry them while standing erect

General Characteristics cont. Swim low in the water - like loons, but with bill tilted up at an angle Swim low in the water - like loons, but with bill tilted up at an angle Eyes adapted for water as well as air Eyes adapted for water as well as air Flocks fly in lines or wedges - like geese Flocks fly in lines or wedges - like geese Silent, except for low grunts occasionally in nesting colonies. Silent, except for low grunts occasionally in nesting colonies. Food - fish, crustaceans Food - fish, crustaceans Range - Nearly cosmopolitan Range - Nearly cosmopolitan

General Characteristics cont. Number of species Number of species –Worldwide - 39 –North America - 6 Great Cormorant Great Cormorant Double-crested Cormorant Double-crested Cormorant Neotropic Cormorant Neotropic Cormorant Brandt’s Cormorant Brandt’s Cormorant Pelagic Cormorant Pelagic Cormorant Red-faced Cormorant Red-faced Cormorant

Neotropic Cormorant Phalacrocorax brasilianus

Identification Length: 22 in. Length: 22 in. Wingspan: 40 in. Wingspan: 40 in. Formerly Olivaceous Cormorant Formerly Olivaceous Cormorant Dull yellow, pointed gular region with thin pale border Dull yellow, pointed gular region with thin pale border Neotropic Cormorant

Range Preferred Breeding Preferred Breeding Open water wetlands Preferred nesting Preferred nesting Low lying trees over water Islands (Telfair, Morrison 1995)

Range, cont. Breeding: – –Subantarctic coast of Cape Horn to Southwestern U.S. – Texas, Louisiana, and New Mexico. Postbreeding: – –Continental U.S. – North to Minnesota, west to California, and east to Mississippi.

Habitat Tidal waters, lakes Tidal waters, lakes –In U.S. Warm southern waters Warm southern waters –fresh –brackish Coastal regions Coastal regions –protected estuaries, rivers, ponds Coastal Islands Coastal Islands Tolerant of all but the most disruptive human activities Tolerant of all but the most disruptive human activities

Feeding Behavior Dives from surface; rarely from air Dives from surface; rarely from air Propelled mainly by feet when swimming Propelled mainly by feet when swimming May forage in groups May forage in groups –work together to drive fish into shallows

Nesting Colony Breeders Colony Breeders Mating displays of males Mating displays of males –sitting with tail raised – bill pointed up –raising and lowering tips of folded wings Both sexes display Both sexes display –stretching neck up –bill open –waving head back and forth

Nesting Cont. Nest Nest –site - live or dead bushes or trees –3 to 25 feet above water –sometimes on ground on islands –males begin nest, females finish Eggs Eggs –3-4 - bluish white, become nest stained –Incubation by both sexes - 25 days

Nesting Cont. Young Young –Both parents feed young until 11th week –Independent at 12 weeks –1 brood per year

Status Population size dropped drastically in Texas until 1960’s Population size dropped drastically in Texas until 1960’s –DDT’s Now Now –Increased/ing in Texas and Louisiana

Red-Faced Cormorant Phalacrocorax urile

Identification Length: 28 in. Length: 28 in. Wingspan: 48 in. Wingspan: 48 in. blue gular region is bordered in bright red that reaches up onto the forehead blue gular region is bordered in bright red that reaches up onto the forehead

I.D. cont. Similar to the Pelagic Cormorant Similar to the Pelagic Cormorant –the two are often confused when seen together Shy habits and inaccessible colony sites Shy habits and inaccessible colony sites –least known and least studied of North Pacific Exclusively marine Exclusively marine –ventures onto land only to breed or roost

Range Breeding Breeding –Aleutian Island Chain –Southeastern Gulf of Alaska Year-round Year-round –Aleutian Islands –Pribilof Islands –few sites in Gulf of Alaska and Northern Sound

Habitat Ocean, Coast, Islands Ocean, Coast, Islands –Close to shore in cool ocean waters –Rocky bays –Straits between Islands

Feeding Behavior Dives from surface Dives from surface propelled by feet when swimming propelled by feet when swimming Forages alone Forages alone May feed near bottom in rocky areas May feed near bottom in rocky areas

Nesting Mixed colony breeder Mixed colony breeder –Often with Pelagic Cormorant contributes to limited understanding of Red-faced’s natural history and ecology contributes to limited understanding of Red-faced’s natural history and ecology Less gregarious and social of all Cormorants Less gregarious and social of all Cormorants Colonies - small and dispersed Colonies - small and dispersed –few are large, but they are remote from human contact

Nesting Cont. Male mating display Male mating display –perches with head over back –bill pointed up –moving head up and down –quickly raising and lowering tips of folded wings - white patches on flanks rapidly covered and exposed

Nesting Cont. Nest Nest –Site - on ledge (wide or narrow) of cliff or steep slope above water –Mound of grass, seaweed, moss, debris –Nest may be reused Eggs Eggs –3 to 4 - bluish white –Incubation by both sexes days

Nesting Cont. Young Young –fed by both parents –Independence estimated at days –1 Brood per year

Status Aleutian populations may have been increasing for several decades. Aleutian populations may have been increasing for several decades. Has expanded range east along southern coast of Alaska Has expanded range east along southern coast of Alaska Becoming common east to Prince William Sound Becoming common east to Prince William Sound

Double-Crested Cormorant Double-Crested Cormorant Phalacrocorax auritus Phalacrocorax auritus

Identification Length: 27 in. Length: 27 in. Wingspan: 50 in. Wingspan: 50 in. Gular area squared off and orange Gular area squared off and orange –extends straight down across throat Orange lores Orange lores Rarely appears crested in the field Rarely appears crested in the field Most generally distributed - only one likely to be seen inland in most areas Most generally distributed - only one likely to be seen inland in most areas

Range Breeding Breeding

Range, cont. Wintering Wintering

Habitat Coasts, bays, lakes, rivers Coasts, bays, lakes, rivers –Very adaptable –may be found in almost any aquatic habitat –Rocky northern coast to mangrove swamps –Large reservoirs to small inland ponds –Nest in trees near or over water, on sea cliffs, or on island ground

Feeding Behavior Dives from surface, not air Dives from surface, not air Propelled by feet when swimming Propelled by feet when swimming –May also use wings! Forage in groups or alone Forage in groups or alone Clear or Muddy Water Clear or Muddy Water Near surface rather than near bottom Near surface rather than near bottom

Nesting Usually breeds only after first three years Usually breeds only after first three years Colony Nester Colony Nester Male displays on water Male displays on water –splashes wings –swims in zigzags –diving and bringing up pieces of weeds Nest site displays by males Nest site displays by males –crouching and vibrating wings while calling

Nesting Cont. Nest Nest –site near water on cliff edge –island ground –any height in a tree Eggs Eggs –3 to 4 - Bluish white, becomes nest stained –Incubation by both sexes; days

Nesting Cont. Young Young –Both parents feed young –Start to wander within colony after 3 to 4 weeks, but return to nest to feed –first flight - 5 to 6 weeks –Independence - 9 to 10 weeks

Status Like Neotropic Cormorant Like Neotropic Cormorant –Numbers dropped through 1960’s DDT’s DDT’s Migratory Bird Treaty Act Migratory Bird Treaty Act Populations began increasing Populations began increasing Range is being expanded Range is being expanded –Pest in some regions!

Management Concerns Double-crested Cormorant Double-crested Cormorant –Increase in Population causing problems in some regions Ban of DDT’s and Ban of DDT’s and other pesticides MBTA MBTA Changes in fish Changes in fish communities in breed- ing range aquiculture additional breeding habitat

Management Concerns Cont. Options Options –All lethal take requires permission from USFWS Depredation Permits Depredation Permits –No permits required for non-lethal harrassment stun guns stun guns scare divices scare divices nets nets

Works Cited Causey, Douglas Red-faced Cormorant. The Birds of North America 617: Glahn, James F. et al A Science-Based Initiative to Manage Double-Crested Cormorant Damage to Southern Aquaculture. USDA and NWRC. Gough, G.A., Sauer, J.R., Iliff, M. Patuxent Bird Identification Infocenter Version Patuxent Wildlife Research Center, Laurel, MD. pwrc.usgs.gov/Infocenter/infocenter.html Peterson Multimedia Guides: North American Birds The Ultimate Birder Disc 1 Telfair, R.C. and M.L. Morrison Neotropic Cormorant. The Birds of North America 137: Wires, L.R. et al The Double-Crested Cormorant in Eastern and Central North America: A Summary of Status and Selected Research 4: 1-5.