Damián Martínez Fernández

Before the surveys, the project changed in form but not in content. We still worked with killer whales, false killer whales and pilot whales, in addition to with coastal communities. Knowledge of the behavior and occurrence of these species is basic for the determining their distribution. Also can be used to indicate dolphin habitat use.

In order to quantify the attitudes and perceptions of the Drake Bay (south Pacific Costa Rica) and Cuajiniquil (north Pacific Costa Rica) communities we decided to hold workshops as well as conduct interviews. Tourism is the main source of income in the first community, whereas fishing generates most income in the second. This meant we would be able to create alternative conservation strategies.

We have been in contact with the Drake Bay guides association and Cuajiniquil’s fishing association, both of which are willing to collaborate with the project.

In addition the area’s high schools are looking forward to the workshops.

Until today we conducted 168 hours (24 days) of sampling resulting in 4 sightings (16% of the number of days). The average number of individuals per group was 13.2 ±4.7 individuals. So far, 25 individuals have been identified.

The predominant behavior was travelling (64%), followed by feeding-foraging (23%).

The distribution of the False killer whale (Pseudorca crassidens) extends from tropical to temperate waters in the Indian, Pacific and Atlantic Oceans and the Mediterranean Sea. In Costa Rican waters False killer whales have been reported in the Pacific and the Caribbean territorial waters. False killer whales reports are particularly concentrated in the South Pacific of Costa Rica, specifically along the coast of Drake-Bay, in Golfo Dulce, and Cocos Island. Despite of these observations, there has not been any systematic study to determine the status of these dolphins in Costa Rican waters.

Therefore, the purpose of this study is to provide a first glimpse in the status of false killer whales in the protected waters of Caño Island, Costa Rica. Following monthly strip-transects the area was surveyed from December 2004 to date (June 2005). Survey effort was 168 hours (24 days). A total of four sightings were made in January and February (16% of the number of days). The average group size was 13.2 ± 4.7 individuals. Twenty-five animals were photo-identified. The predominant behavior was traveling (64%), followed by feeding-foraging (23%). January and February are dry months characterized by an increase in water productivity. The abundance and behavioral patterns of other two common delphinid species (Stenella attenuata and Tursiops truncatus) appear to vary seasonally in the Costa Rican Pacific waters, reaching a peak in abundance and bias towards foraging activities during these dry months. It is possible that False killer whales occurrence may be also associated with the seasonality of the area.

Read about the progress of his project in the Final Report below.