Behavior of humpback whales, Megaptera novaeangliae (Cetacea: Balaenopteridae): comparisons between two coastal areas of Brazil

Abstract

Behavior of humpback whales was observed during the reproductive period off the northern coast of the state of Bahia (NB, n = 378 groups) and at the Abrolhos Bank (AB, n = 919) to compare patterns and group composition between the two locations. Alone individuals and dyads were most often encountered in both areas, although mother-calf pairs were more common in AB. While these two regions comprise distinct concentrations of humpback whales, with intrinsic environmental differences, behavior patterns were quite similar. The only behavioral differences found where for "tail up" and "resting". The patterns found here may reflect differences in the protection status of the areas or intrinsic environmental differences.

Low latitude habitat use patterns of a recovering population of humpback whales

“…The proportions relating to group composition observed are identical to the areas surveyed north of Serra Grande (Lunardi et al , 2008; Rossi-Santos et al , 2008). The proportion of groups with calves is much smaller in Serra Grande (21%) than around the Abrolhos Archipelago (48%) (Morete et al , 2007), which is within the main calving ground for the population that migrates to Brazil.…”

“…For years, all research efforts were focused in the Abrolhos region (Martins et al , 2001; Morete et al , 2003), which continues to be the main breeding area (Andriolo et al , 2006; 2010). However, the species occurs along the entire north-eastern coast of Brazil (Zerbini et al , 2004; Lunardi et al , 2008) and the population shows a significant expansion northern of Abrolhos, reoccupying winter areas (Rossi-Santos et al , 2008; Andriolo et al , 2010) used before the whaling period (Morais et al , 2016). Surveys carried out between 2002 and 2005 showed a gradual increase in the Brazilian population reaching 6404 individuals in 2005 (Andriolo et al , 2010).…”

Behavioural strategies in humpback whales,Megaptera novaeangliae, in a coastal region of Brazil

“…However, head-lunging is frequently used by secondary escorts to dislodge the main escort Groups of one and two adults, with or without calves (alone, two adult whales, mother and calf and mother and calf and one escort), were classified according to occurrence criteria adopted in this study as Highly usual or Usual. The predominance of groups of one and two adults without calves was also observed by Martins et al (2001) and Lunardi et al (2008) in the Abrolhos Bank and by Baker & Herman (1984) and Craig et al (2002) in Hawaii. However, the present study had high occurrence probabilities of groups of mothers and calves, classified here as Highly usual.…”

“…The Abrolhos Bank (Bahia, Brazil) is the main breeding ground for humpback whales in the western South Atlantic (Martins et al , 2001; Morete et al , 2003b; Lunardi et al , 2008), but the species has been recorded from 3°S to 31°S (e.g. Pinedo, 1985; Lodi, 1994; Zerbini et al , 2006; Neto et al , 2007; Rossi-Santos et al , 2008; Meirelles et al , 2009).…”

“…The distribution of humpback whales according to water depth has been described as a function of social organization, with mothers and their calves occurring more frequently in shallow waters, compared with all other types of groups (Martins et al , 2001; Zerbini et al , 2004). High concentrations of groups with calves are found near the Abrolhos Archipelago (Martins et al , 2001; Morete et al , 2003b; Lunardi et al , 2008).…”