Humpback whale song occurs extensively on feeding grounds in the western North Atlantic Ocean

Abstract

Male humpback whales produce complex, patterned songs that are traditionally heard on their breeding grounds. Short-term studies demonstrated that they also sing along mi - gration routes and on higher-latitude feeding grounds. This study expands the current under- standing of feeding-ground song by providing yearlong views of singing activity. Acoustic record- ings were made in Stellwagen Bank National Marine Sanctuary, part of the western North Atlantic Ocean feeding grounds. Recordings were made in 2006 and 2008. Song occurred during all months except February 2006 and June 2008. Song occurred most frequently in November for both years (mean ± SE — 2006: 18.26 ± 0.66 h with song d -1 ; 2008: 18.59 ± 0.82 h with song d �1 ). The longest song sessions occurred in April for both years (2220 ± 348, 1430 ± 274 s, respectively) in November and December for 2006, and in May for 2008. This study demonstrates that song occurs often, when whales arrive at the feeding grounds in early April. The occurrence and length of song sessions decrease during July and August when whales are observed to be feeding in the sanctuary. Song occurrence and song session length increase when most males prepare to migrate southward in October to December. Such patterns are congruent with the hypothesis of seasonal hormonal activity and its potential role in song production.