Humpback whales use the waters off the Pacific coast of Central America as a breeding ground, a distinctive population segment classified as endangered. However, their resighting and behavioral patterns there are not well understood. We examined their behavior and resighting patterns off Guatemala, and compared their sighting history in neighboring breeding grounds and feeding grounds along the U.S. West Coast using the long-term database maintained by Cascadia Research Collective (CRC). Behavior was examined using focal animal observations and continuous sampling (activity, nearest neighbor, group size). Behavior such as singing was monitored using acoustic stations in Guatemala. Ninety-seven whales were individually identified in Guatemala (with additional past IDs conducted in collaboration with CRC including 2006/2008 by P. Godoy); only one whale was resighted in different years (1999, 2009), three others were resighted in the same season, and 17 were seen in other breeding grounds (Mexico, elsewhere in Central America). The majority of the whales were resighted in the feeding grounds along the U.S. West Coast (84%). The low resighting rate within Guatemala suggests that humpback whales do not reside in this particular breeding ground. This was further confirmed by examination of activities. Five surface activities were recorded in 15.90 h of focal animal observations but one activity, traveling, was particularly common (92%; X2 = 1329.03, p < 0 .001). Singing was recorded in all but two stations suggesting that the activity, characteristic of the breeding season, was also very common. Calves were sighted in 28% of the groups and those groups were significantly larger than non-calf groups (Mann-Whitney U = 106, p < 0 .001). Most groups (63%) contained 2-4 whales (1.94±0.12). The observations represent some of the first quantifications of behavior and resighting history of humpback whales in Guatemala. They also provide insights into the importance of specific locations to this endangered population.
Citation:
Quintana, E., J. Calambokidis. 2017. Resighting patterns and behavior of humpback whales sighted in a tropical breeding ground off Guatemala.