Orcinus orca (Cetacea; Delphinidae in coastal waters of the State of Rio de Janeiro)

With the aim of updating and complementing records of occurrences of orcas (Orcinus orca) in the state of Rio de Janeiro (21°18'S ; 23°21'W), this paper brings together new information on sightings of this species. Between October 22, 1992 and November 12, 1997, on 14 different occasions, 61 individuals were observed between Ponta da Trindade and Búzios. Of the total number of sightings, 42.8% occurred during spring. Group size ranged from 1 to 10 individuals, with an average of 4.3. Cubs were present in 35.7% of the sightings. The presence of O. orca in coastal and shallow waters off Rio de Janeiro was always associated with bad weather and/or cold water. After the second record of orcas in Rio de Janeiro, the species was not reported again for eleven years.

Gathering records from the literature and personal communications about the occurrence of orcas in the states of Rio de Janeiro, São Paulo and Espírito Santo, along a stretch of about 1459.9 km of coastline, it can be seen that after 1992 sightings of this species have been gradually increasing on the southeast coast of Brazil, which may be a consequence of greater observation efforts in this region.

Liliane Lodi e Bia Hetzel

- 19 Downloads

Orcinus orca (Cetacea; Delphinidae in coastal waters of the State of Rio de Janeiro)

With the aim of updating and complementing records of occurrences of orcas (Orcinus orca) in the state of Rio de Janeiro (21°18'S ; 23°21'W), this paper brings together new information on sightings of this species. Between October 22, 1992 and November 12, 1997, on 14 different occasions, 61 individuals were observed between Ponta da Trindade and Búzios. Of the total number of sightings, 42.8% occurred during spring. Group size ranged from 1 to 10 individuals, with an average of 4.3. Cubs were present in 35.7% of the sightings. The presence of O. orca in coastal and shallow waters off Rio de Janeiro was always associated with bad weather and/or cold water. After the second record of orcas in Rio de Janeiro, the species was not reported again for eleven years.

Gathering records from the literature and personal communications about the occurrence of orcas in the states of Rio de Janeiro, São Paulo and Espírito Santo, along a stretch of about 1459.9 km of coastline, it can be seen that after 1992 sightings of this species have been gradually increasing on the southeast coast of Brazil, which may be a consequence of greater observation efforts in this region.

Liliane Lodi e Bia Hetzel

- 19 Downloads

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