Cormorants corvus marinus - sea crow. Systematics Order - Pelecaniformes Order - Pelecaniformes –Suborder - Pelecani Family - Phalacrocoracidae Family

CormorantsCormorantscorvus marinus - sea crow

SystematicsSystematics• Order - PelecaniformesOrder - Pelecaniformes

– Suborder - PelecaniSuborder - Pelecani•Family - PhalacrocoracidaeFamily - Phalacrocoracidae

•Subfamilies Subfamilies – Phalacrocoracinae - CormorantsPhalacrocoracinae - Cormorants

robust billsrobust bills stocky bodiesstocky bodies breed in colonies near lakes or riversbreed in colonies near lakes or rivers

– Leucocarboninae - ShagsLeucocarboninae - Shags longer, slender bills, heads and bodieslonger, slender bills, heads and bodies never far from marine habitats and rocky never far from marine habitats and rocky

shoresshores

General CharacteristicsGeneral Characteristics

• Large, blackish water birdsLarge, blackish water birds

• long, hooked billlong, hooked bill

• long tail and long, thin neck long tail and long, thin neck

• colorful gular pouches and face skincolorful gular pouches and face skin

• usually have green eyesusually have green eyes

• sexes alikesexes alike

• Common sight: Wings stretched to dry Common sight: Wings stretched to dry them while standing erect them while standing erect

General Characteristics General Characteristics cont.cont.

• Swim low in the water - like loons, but Swim low in the water - like loons, but with bill tilted up at an anglewith bill tilted up at an angle

• Eyes adapted for water as well as airEyes adapted for water as well as air

• Flocks fly in lines or wedges - like geeseFlocks fly in lines or wedges - like geese

• Silent, except for low grunts occasionally Silent, except for low grunts occasionally in nesting colonies.in nesting colonies.

• Food - fish, crustaceansFood - fish, crustaceans

• Range - Nearly cosmopolitanRange - Nearly cosmopolitan

General Characteristics General Characteristics cont.cont.

• Number of species Number of species – Worldwide - 39Worldwide - 39– North America - 6North America - 6

•Great CormorantGreat Cormorant

•Double-crested CormorantDouble-crested Cormorant

•Neotropic CormorantNeotropic Cormorant

•Brandt’s CormorantBrandt’s Cormorant

•Pelagic CormorantPelagic Cormorant

•Red-faced CormorantRed-faced Cormorant

Neotropic CormorantNeotropic CormorantPhalacrocorax brasilianusPhalacrocorax brasilianus

IdentiIdentificationfication

• Length: 22 in.Length: 22 in.

• Wingspan: 40 in.Wingspan: 40 in.

• Formerly Olivaceous CormorantFormerly Olivaceous Cormorant

• Dull yellow, pointed gular region with thin Dull yellow, pointed gular region with thin pale borderpale border

Neotropic Cormorant

RangeRange• Preferred BreedingPreferred Breeding

• Open water wetlandsOpen water wetlands

• Preferred nestingPreferred nesting • Low lying trees over Low lying trees over

waterwater

• Islands Islands

(Telfair, Morrison (Telfair, Morrison 1995)1995)

Range, cont.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.

HabitatHabitat

• Tidal waters, lakesTidal waters, lakes– In U.S. In U.S.

•Warm southern watersWarm southern waters– freshfresh– brackishbrackish

•Coastal regionsCoastal regions– protected estuaries, rivers, pondsprotected estuaries, rivers, ponds

•Coastal IslandsCoastal Islands

• Tolerant of all but the most Tolerant of all but the most disruptive human activitiesdisruptive human activities

Feeding BehaviorFeeding Behavior

• Dives from surface; rarely from airDives from surface; rarely from air

• Propelled mainly by feet when Propelled mainly by feet when swimmingswimming

• May forage in groupsMay forage in groups– work together to drive fish into shallowswork together to drive fish into shallows

NestingNesting

• Colony BreedersColony Breeders

• Mating displays of malesMating displays of males– sitting with tail raisedsitting with tail raised– bill pointed upbill pointed up– raising and lowering tips of folded wingsraising and lowering tips of folded wings

• Both sexes displayBoth sexes display– stretching neck upstretching neck up– bill openbill open– waving head back and forthwaving head back and forth

Nesting Cont.Nesting Cont.

• NestNest– site - live or dead bushes or treessite - live or dead bushes or trees– 3 to 25 feet above water3 to 25 feet above water– sometimes on ground on islandssometimes on ground on islands– males begin nest, females finishmales begin nest, females finish

• EggsEggs– 3-4 - bluish white, become nest stained3-4 - bluish white, become nest stained– Incubation by both sexes - 25 daysIncubation by both sexes - 25 days


• YoungYoung– Both parents feed young until 11th weekBoth parents feed young until 11th week– Independent at 12 weeksIndependent at 12 weeks– 1 brood per year1 brood per year

StatusStatus

• Population size dropped drastically in Population size dropped drastically in Texas until 1960’sTexas until 1960’s– DDT’sDDT’s

• NowNow– Increased/ing in Texas and LouisianaIncreased/ing in Texas and Louisiana

Red-Faced CormorantRed-Faced CormorantPhalacrocorax urilePhalacrocorax urile

IdentificationIdentification



• blue gular region is blue gular region is bordered in bright bordered in bright red that reaches up red that reaches up onto the foreheadonto the forehead

I.D. cont.I.D. cont.

• Similar to the Pelagic CormorantSimilar to the Pelagic Cormorant– the two are often confused when seen the two are often confused when seen

togethertogether

• Shy habits and inaccessible colony sitesShy habits and inaccessible colony sites– least known and least studied of North least known and least studied of North

PacificPacific

• Exclusively marineExclusively marine– ventures onto land only to breed or roostventures onto land only to breed or roost

RangeRange

• BreedingBreeding– Aleutian Island ChainAleutian Island Chain– Southeastern Gulf of Southeastern Gulf of

AlaskaAlaska

• Year-roundYear-round– Aleutian IslandsAleutian Islands– Pribilof IslandsPribilof Islands– few sites in Gulf of few sites in Gulf of

Alaska and Northern Alaska and Northern SoundSound

HabitatHabitat

• Ocean, Coast, IslandsOcean, Coast, Islands– Close to shore in cool ocean watersClose to shore in cool ocean waters– Rocky baysRocky bays– Straits between IslandsStraits between Islands


• Dives from surfaceDives from surface

• propelled by feet when swimmingpropelled by feet when swimming

• Forages aloneForages alone

• May feed near bottom in rocky areasMay feed near bottom in rocky areas

NestingNesting• Mixed colony breederMixed colony breeder

– Often with Pelagic CormorantOften with Pelagic Cormorant•contributes to limited understanding of Red-contributes to limited understanding of Red-

faced’s natural history and ecology faced’s natural history and ecology

• Less gregarious and social of all Less gregarious and social of all CormorantsCormorants

• Colonies - small and dispersed Colonies - small and dispersed – few are large, but they are remote from few are large, but they are remote from

human contacthuman contact


• Male mating displayMale mating display– perches with head over backperches with head over back– bill pointed upbill pointed up– moving head up and downmoving head up and down– quickly raising and lowering tips of quickly raising and lowering tips of

folded wings - white patches on flanks folded wings - white patches on flanks rapidly covered and exposedrapidly covered and exposed


• NestNest– Site - on ledge (wide or narrow) of cliff Site - on ledge (wide or narrow) of cliff

or steep slope above wateror steep slope above water– Mound of grass, seaweed, moss, debrisMound of grass, seaweed, moss, debris– Nest may be reused Nest may be reused

• EggsEggs– 3 to 4 - bluish white3 to 4 - bluish white– Incubation by both sexes - 31-34 daysIncubation by both sexes - 31-34 days


• YoungYoung– fed by both parentsfed by both parents– Independence estimated at 50-60 daysIndependence estimated at 50-60 days– 1 Brood per year1 Brood per year

StatusStatus

• Aleutian populations may have been Aleutian populations may have been increasing for several decades.increasing for several decades.

• Has expanded range east along Has expanded range east along southern coast of Alaskasouthern coast of Alaska

• Becoming common east to Prince Becoming common east to Prince William SoundWilliam Sound

Double-Crested Double-Crested CormorantCormorant

Phalacrocorax Phalacrocorax auritusauritus

IdentificationIdentification



• Gular area squared off and orangeGular area squared off and orange– extends straight down across throatextends straight down across throat

• Orange loresOrange lores

• Rarely appears crested in the field Rarely appears crested in the field

• Most generally distributed - only one Most generally distributed - only one likely to be seen inland in most areaslikely to be seen inland in most areas

RangeRange

• Breeding Breeding

Range, cont.Range, cont.

• WinteringWintering

HabitatHabitat

• Coasts, bays, lakes, riversCoasts, bays, lakes, rivers– Very adaptableVery adaptable– may be found in almost any aquatic may be found in almost any aquatic

habitathabitat– Rocky northern coast to mangrove Rocky northern coast to mangrove

swampsswamps– Large reservoirs to small inland pondsLarge reservoirs to small inland ponds– Nest in trees near or over water, on sea Nest in trees near or over water, on sea

cliffs, or on island groundcliffs, or on island ground


• Dives from surface, not airDives from surface, not air

• Propelled by feet when swimmingPropelled by feet when swimming– May also use wings!May also use wings!

• Forage in groups or aloneForage in groups or alone

• Clear or Muddy WaterClear or Muddy Water

• Near surface rather than near bottomNear surface rather than near bottom

NestingNesting

• Usually breeds only after first three yearsUsually breeds only after first three years

• Colony NesterColony Nester

• Male displays on waterMale displays on water– splashes wingssplashes wings– swims in zigzagsswims in zigzags– diving and bringing up pieces of weedsdiving and bringing up pieces of weeds

• Nest site displays by malesNest site displays by males– crouching and vibrating wings while callingcrouching and vibrating wings while calling


• NestNest– site near water on cliff edgesite near water on cliff edge– island groundisland ground– any height in a treeany height in a tree

• EggsEggs– 3 to 4 - Bluish white, becomes nest 3 to 4 - Bluish white, becomes nest

stainedstained– Incubation by both sexes; 25 - 33 daysIncubation by both sexes; 25 - 33 days


• YoungYoung– Both parents feed youngBoth parents feed young– Start to wander within colony after 3 to Start to wander within colony after 3 to

4 weeks, but return to nest to feed4 weeks, but return to nest to feed– first flight - 5 to 6 weeksfirst flight - 5 to 6 weeks– Independence - 9 to 10 weeksIndependence - 9 to 10 weeks

StatusStatus

• Like Neotropic CormorantLike Neotropic Cormorant– Numbers dropped through 1960’sNumbers dropped through 1960’s

•DDT’sDDT’s

• 1972 - Migratory Bird Treaty Act1972 - Migratory Bird Treaty Act

• Populations began increasing Populations began increasing

• Range is being expanded Range is being expanded – Pest in some regions!Pest in some regions!

Management ConcernsManagement Concerns

• Double-crested CormorantDouble-crested Cormorant– Increase in Population causing problems in Increase in Population causing problems in

some regionssome regions• Ban of DDT’s andBan of DDT’s and

other pesticidesother pesticides

• MBTA - 1972MBTA - 1972

• Changes in fish Changes in fish

communities in breed-communities in breed-

ing rangeing range

• • aquiculture

• additional breeding habitat

Management Concerns Management Concerns Cont.Cont.

• OptionsOptions– All lethal take requires permission from All lethal take requires permission from

USFWSUSFWS•Depredation PermitsDepredation Permits

– No permits required for non-lethal No permits required for non-lethal harrassmentharrassment•stun gunsstun guns

•scare divicesscare divices

•netsnets

Works CitedWorks Cited• Causey, Douglas 2002. Red-faced Cormorant. The Birds of

North America 617: 1-16.

• Glahn, James F. et al. 2000. 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. 1998. Version 97.1. Patuxent

Wildlife Research Center, Laurel, MD. http://www.mbr-

pwrc.usgs.gov/Infocenter/infocenter.html

• Peterson Multimedia Guides: North American Birds. 2002. The Ultimate Birder Disc 1

• Telfair, R.C. and M.L. Morrison 1995. Neotropic Cormorant. The Birds of North America 137: 1-22.

• Wires, L.R. et al. 2000. The Double-Crested Cormorant in Eastern and Central North America: A Summary of Status and Selected Research 4: 1-5.

Documents

Cormorants corvus marinus - sea crow. Systematics Order - Pelecaniformes Order - Pelecaniformes –Suborder - Pelecani Family - Phalacrocoracidae Family