Abstract
We report the location and size of reproductive colonies of cormorant species in the Deseado estuary (Argentina). Five colonies of Red-legged Cormorants (Phalacrocorax gaimardi), Rock Cormorants (P. magellanicus), and Neotropic Cormorants (P. olivaceus) were counted. The Red-legged Cormorant is the most abundant and more widely distributed cormorant species within the estuary. Estimated reproductive populations are 588,306 and 186 individuals for the Red-legged Cormorant, Neotropic Cormorant and Rock Cormorant, respectively. Although Rock Cormorants nest in a cliffused also by Red-Iegged Cormorants, Iimits between their colonies are well established. Given their magnitude, cormorant colonies at Puerto Deseado should be highlighted for conservation purposes.
References
DANERI,C.A.1960.LaNidificacióndelBiguáPhala-crocoraxolivaceusolivaceus(Humboldt)enPuer-toDeseado.Physis(Bs.As.)21(61):273-277.
GANDINI,P.yE.FRERE.1995.Distribución,abundanciay cicloreproductivodelCormoránGrisPhalacro-coraxgaimardienlacostapatagónica,Argentina.Hornero14:57-60.
HUMPHREY,P.S.;D.SIEGELCAUSEY&P.C.RASMUSSEN.1985.InformeSobrelaInvestigaciónOrnitológicaRealizadaenlaProvinciadeSantaCruzy Chubut(Argentina).MuseodeHistoriaNatural,UniversidaddeKansas.38pp.
MALACALZA,V.E.1984.AvesGuaneras.RelevamientodeEspeciesenTresCormoranerasContinentalesdela ProvinciadelChubut(Argentina)(Pelecaniformes-Phalacrocoracidae).CentroNacionalPatagónico,Pto.Madryn,84:13pp.
PUNTA,G.&J. SARAVIA.1989.GuanerasdelaProvinciadelChubut.PotencialidadProductivay Fundamen-tosParaSuManejoRacional.DireccióndeInteresesMaritimosy PescaContinentaldelaProvinciadelChubut.107pp.

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