WI - Cormorant Research Group The Bulletin - No. 3, December 1998 Original papers

RECENT AND CURRENT RESEARCH ON CORMORANTS IN ARGENTINA

Ricardo Casaux

Instituto Antártico Argentino, Cerrito 1248, 1010 Buenos Aires, Argentina. e-mail: pipocasaux@overnet.com.ar

Cormorants are well represented in Argentina with six species distributed along the Patagonian coast and sub-Antarctic islands: Phalacrocorax albiventer, Phalacrocorax atriceps, Phalacrocorax bougainvillii, Phalacrocorax gaimardi, Phalacrocorax magellanicus and Phalacrocorax olivaceus. Three of these species are also reported to inhabit inner waters such as P. atriceps at the Nahuel Huapi Lake, P. magellanicus at the Fagnano Lake, whereas P. olivaceus is widespread throughout the Argentine territory (Narosky & Yzurieta 1987) (Fig. 1).

Several authors had reported on the distribution of cormorants in Argentina (Carrara 1952, Gonzalez Ruiz 1955, Lopez 1957, Navas 1970, among others) however, by the eighties the information on this matter was still poor and fragmentary with an almost complete lack of detailed information on reproductive and alimentary aspects. In consequence and considering the potential impact of increasing human activities on these birds (mainly fishing activities and tourism), during the lasts years several projects were aimed to understand on the cormorants’ biology, distribution and populational trends, which markedly improved the knowledge of these birds in Argentina. The aim of this note is summarise most of the recent and current Argentine research programmes on cormorants.

Abundance, distribution and populational trends.

Several projects deal with populational aspects of cormorants along the Patagonian coast. Punta & Saravia (1993) reported on the distribution and abundance of P. magellanicus along the Chubut coast. At the same province, P. Yorio and colleagues are conducting long term monitoring programs on the abundance of P. atriceps, P. bougainvillii, P. magellanicus and P. olivaceus at León and Tombo points (see Yorio et al. 1994).

Patricia Gandini and Esteban Frere are conducting studies on the distribution and abundance of P. gaimardi along the Patagonian coast (see Gandini & Frere 1995). They are also developing similar studies on P. atriceps and P. magellanicus but restricted to the Santa Cruz.

Figure 1. Map of Argentina showing some of the study areas on cormorants.

Schiavini & Yorio (1995) provided information on the abundance and distribution of P. atriceps and P. magellanicus at the Beagle Channel, Tierra del Fuego Province, whereas A. Schiavini obtained information on the status of cormorant populations all along the Tierra del Fuego coast, including de los Estados Island. Currently, Yorio et al. (in press) are editing a special publication where the information on the abundance and distribution of cormorants from Bahía Blanca (Buenos Aires Province) to de los Estados Island (Tierra del Fuego) is updated.

On the other hand, G. Iglesias and E. Ramilo are monitoring populational trends in P. atriceps at Victoria Island in the Nahuel Huapi Lake.

Other aspects related to the status of colonies of cormorants such as effects of human activities in colonies of P. atriceps and P. olivaceus (Yorio & Quintana 1996, Yorio et al. 1996) and Kelp Gull predation on colonies of P. atriceps (Quintana & Yorio in press) were also considered.

Breeding biology

The breeding biology of P. albiventer was studied at Tombo Point (Malacalza 1984a) and at León Point (Malacalza & Navas 1996), Chubut. Punta & Saravia (1993) and Malacalza (1995) developed similar studies on P. magellanicus also along the Chubut coast, whereas Gandini & Frere (1995) did on P. gaimardi at Santa Cruz Province, a project still in force.

Diet and foraging behaviour

Aspects related to the diet and foraging behaviour of different cormorant species were intensively considered at different localities. The diet of P. albiventer was recently studied at León Point (Malacalza et al. 1994) and at Lobería Point (Gosztonyi & Kuba in revision), Chubut. Punta et al. (1993) analysed the diet composition and foraging strategies of P. atriceps and P. magellanicus at two localities of the Chubut coast, whereas Malacalza et al. (in press) also studied the diet of P. magellanicus at Loma Point, Chubut. Currently, F. Quintana is studying the diet, diving and foraging strategies and feeding areas of P. magellanicus also at Loma Point.

Nesting behaviour

Martín de la Peña (1980) conducted studies on nesting behaviour in P. olivaceus at Monte Vera, Santa Fe Province, and at de los Pájaros Island, Chubut. Similar studies were also carried out on P. magellanicus at de los Pájaros Island, on P. gaimardi at Puerto Deseado, Santa Cruz, and on P. albiventer, P. atriceps and P. bougainvillii at Tombo Point, Chubut.

Guano related studies

The guano (excreta of cormorants) was intensively exploited in the past and although this industry decreased is still considered of interest for local economies. Thus, several studies on cormorants were related to the production of guano and to the management of this resource (Malacalza 1984b and 1994, Punta 1989, among others). Recently, Punta (1996) provided detailed information on the status of this resource at Río Negro, Chubut and Santa Cruz Province, and summarised the characteristics of its composition, of the guano-producing colonies, of the development of the activity as well as of management plans. Esteban Frere and Patricia Gandini are developing similar studies but focused on P. atriceps at Santa Cruz Province.

References

Carrara, I. 1952. Lobos marinos, pingüinos y guaneras del litoral marítimo e islas adyacentes de la República Argentina. Univ. Nac. de la Plata, Fac. Cs. Veterinarias, 191 pp.

De la Peña, M. 1980. Notas nidológicas sobre Biguaes y Cormoranes (Aves: Anhingidae y Phalacrocoracidae). Historia Natural, 1 (16): 109-112.

Gandini, P. & E. Frere 1995. Distribución, abundancia y ciclo reproductivo del Cormorán Gris (Phalacrocorax gaimardi) en la costa patagónica, Argentina. El Hornero, 14(1-2): 57-60.

Gonzalez Ruiz, G. 1955. Fauna del litoral atlántico: Lobos y elefantes marinos, pingüinos y aves guaneras. Natura, 1: 121-129.

Gosztonyi & Kuba in revision. Fishes in the diet of the Imperial Cormorant Phalacrocorax atriceps at Punta Lobería (Chubut, Argentina). Marine Ornithology.

Lopez, R. 1957. Las guaneras de las Islas Viana, Galiano y Lobos de la Bahía Bustamante, Chubut. Rev. Mus. De Mar del Plata, 1: 47-54.

Malacalza, V. 1984a. Biología reproductiva de Phalacrocorax albiventer. I. Nidificación en Punta Tombo. Centro Nacional Patagónico, Contribución 98, 13 pp.

Malacalza, V. 1984b. Aves guaneras. Relevamiento de especies en tres cormoraneras continentales de la Provincia del Chubut (Argentina) (Pelecaniformes-Phalacrocoracidae). Centro Nacional Patagónico, Contribución 84, 13 pp.

Malacalza, V. 1994. La producción de guano del Cormorán Real en condiciones de cautiverio. Neotrópica, 40(103-104): 15-18.

Malacalza, V. 1995. Aportes al conocimiento de la biología reproductiva de Phalacrocorax magellanicus (Aves: Phalacrocoracidae). Neotrópica, 41 (105-106): 27-30.

Malacalza, V., M. Bertellotti & T. Poretti, in press. Variación estacional de la dieta de Phalacrocorax magellanicus (Aves: Phalacrocoracidae) en Punta Loma (Chubut, Argentina). Neotrópica.

Malacalza, V. & J. Navas 1996. Biología y ecología reproductiva de Phalacrocorax albiventer (Aves: Phalacrocoracidae) en Punta León, Chubut, Argentina. Ornitología Neotropical, 7: 53-61.

Malacalza, V., T. Poretti, & M. Bertellotti 1994. La dieta de Phalacrocorax albiventer en Punta León (Chubut, Argentina) durante la temporada reproductiva. Ornitología Neotropical, 5: 91-97.

Narosky, T. & D. Yzurieta 1987. Guía para la identificación de las aves de Argentina y Uruguay. Asociación Ornitológica del Plata (eds.), 346 pp.

Navas, J. 1970. Los cormoranes del Lago Nahuel Huapi. Neotrópica, 16(51): 140-144.

Punta, G. 1989. Guaneras de la Provincia del Chubut: Potencialidad productiva y fundamentos para su manejo racional. Rawson: Dirección de Impresiones Oficiales, 113 pp.

Punta, G. 1996. Estado de situación del recurso guanero en la República Argentina. Fundación Patagonia Natural, Informe Técnico Nº 6, 18pp.

Punta, G. & J. Saravia 1993. Distribución, abundancia y aspectos de la biología reproductiva del Cormorán de Cuello Negro Phalacrocorax magellanicus en la Provincia del Chubut, Argentina. Hornero, 13: 295-298.

Punta, G., J. Saravia & P. Yorio 1993. The diet and foraging behaviour of two Patagonian cormorants. Marine Ornithology, 21: 27-36.

Quintana, F. & P. Yorio in press. Kelp Gull predation on an Imperial Cormorant colony in Patagonia. Marine Ornithology.

Schiavini, A. & P. Yorio 1995. Distribution and abundance of seabird colonies in the Argentine Sector of the Beagle Channel, Tierra del Fuego. Marine Ornithology, 23: 39-46.

Yorio, P., E. Frere, P. Gandini & G. Harris in press. Atlas de la distribución reproductiva de aves marinas de la Patagonia Argentina. Plan de Manejo Integrado de la Zona Costera Patagónica. Fundación Patagonia Natural y Wildlife Conservation Society.

Yorio, P., P. Gandini, & E. Frere 1996. Disturbios humanos sobre aves marinas: efectos sobre la reproducción y su relación con el manejo de visitantes a las colonias. Informes Técnicos del Plan de Manejo de la Zona Costera Patagónica Nº 23: 1-18.

Yorio, P. & F. Quintana 1996. Efectos del disturbio humano sobre una colonia mixta de aves marinas en Patagonia. El Hornero, 14: 89-96.

Yorio, P., F. Quintana, C. Campagna, & G. Harris 1994. Diversidad, abundancia y dinámica espacio-temporal de la colonia mixta de aves marinas en Punta León, Patagonia. Ornitología Neotropical, 5: 69-77.


Ricardo Casaux, Instituto Antártico Argentino, Cerrito 1248, 1010 Buenos Aires, Argentina. e-mail: pipocasaux@overnet.com.ar