SC/61/SH2 DISTRIBUTION AND SEASONAL OCCURRENCE OF HUMPBACK WHALES (Megaptera novaeangliae) COWS WITH CALVES IN

• Main Authors: Coastal Waters, Of Ecuador, O Félix, Natalia Botero-acosta
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: KEY WORDS; South America; humpback whales; breeding grounds; distribution; conservation; Megaptera novaeangliae
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.604.105; http://www.iwcoffice.co.uk/_documents/sci_com/SC61docs/SC-61-SH2.pdf

The distribution and seasonal occurrence of humpback whales (Magaptera novaeangliae) cows with calves were analyzed during the breeding season (June-October) around the Santa Elena Peninsula, Ecuador (2°10 ' S, 81°00 ' W). In 571 trips carried out between 2001 and 2008 aboard whalewatching boats, 135 groups containing cows with calves were recorded: 89 cow/calf pairs alone (CC) and 46 accompanied by one or more escort whales (CE). CC groups distributed in significantly shallower waters than CE groups (18.79m, SD = 9.66 and 23.63m, SD = 10.81, respectively; p = 0.011); particularly during the afternoon hours when the difference was around 8m. However, the distance of the sightings to the coast was not significantly different. First CE groups were recorded 20 days after the first CC groups and peaked with a delay of five days in respect to CC groups, suggesting a segregation of cow/calf pairs in the first days after birthing. Two cow/calf pairs were recorded with the same escort, in one case after one day and in a second case after four days. The maximum span of time for an identified cow with calf in the breeding area was 61 days. Our results show similarities with other breeding areas but also some differences, which are likely caused by different breeding and nursing strategies associated to particular environmental, ecological and social pressures. We warned about the potential impact that the increase of coastal activities may have on cows with calves nursing around this area.