Satellite-monitored movements of humpback whales Megaptera novaeangliae in the Southwest Atlantic Ocean

Abstract

Southern Hemisphere humpback whales Megaptera novaeangliae migrate from wintering grounds in tropical latitudes to feeding areas in the Antarctic Ocean. It has been hypothesized that the population wintering off eastern South America migrates to feeding grounds near the Antarctic Peninsula (ca. 65°S, 60°W) and/or South Georgia (54°20' S, 36°40' W), but direct evidence to support this has never been presented. Between 19 and 28 October 2003, 11 humpback whales (7 females and 4 males) were instrumented with satellite transmitters off Brazil (ca. 18°30' S, 39°30' W) to investigate their movements and migratory destinations. Mean tracking time for the whales was 39.6 d (range = 5 to 205 d) and mean distance travelled was 1673 km per whale (range = 60 to 7258 km). Movements on the wintering ground showed marked individual variation. Departure dates from the Brazilian coast ranged from late October to late December. Whales migrated south through oceanic waters at an average heading of 170°and travelled a relatively direct, linear path from wintering to feeding grounds. Two whales were tracked to feeding grounds in offshore areas near South Georgia and in the South Sandwich Islands (58°S, 26°W) after a 40 to 60 d long migration. Historical catches and current sighting information support these migratory routes and destinations. This study is the first to describe the movements of humpback whales in the western South Atlantic Ocean.

Horizontal niche partitioning of humpback and fin whales around the West Antarctic Peninsula: evidence from a concurrent whale and krill survey

“…Their nearshore breeding areas are located in the Atlantic, Indian Ocean and Pacific. Their feeding areas in the Southern Ocean cannot be delineated with much precision (Reilly et al 2008), but humpback whales feeding along the WAP likely belong to breeding stock G (Dalla Rosa et al 2008;Zerbini et al 2011;IWC 2015), wintering off the west coast of Central and South America (Stevick et al 2004;Dalla Rosa et al 2008;Secchi et al 2011). BS is considered an important feeding ground for humpback whales of breeding stock G (Dalla Rosa et al 2008), which is one of the less studied of the seven breeding stocks (Secchi et al 2011).…”

Movements and habitat use of reef manta rays off eastern Australia: offshore excursions, deep diving and eddy affinity revealed by satellite telemetry

“…'CE' marks the presence of the Capricorn Eddy feature in the satellite signal, and white arrows denote intrusions of upwelled oceanic wa ters onto the shelf. EAC = East Australian Current migrations are typically attributed to the need to reproduce and exchange genetic material between members of separate populations (Bonfil et al 2005, Skomal et al 2009) or the search for abundant food resources (Zerbini et al 2006, Anderson et al 2011. The question of sex-biased dispersal in M. alfredi could not be assessed here because of our limited data, despite tagged females noticeably dispersing farther than the 2 males.…”

“…Such studies have shed new light on the ecology of marine predators, unravelling a variety of behaviours ranging from localised movements made in relation to foraging opportunities (Sims et al 2006, Papastamatiou et al 2012) to larger-scale migrations (Bonfil et al 2005, Block et al 2011. In most cases, movements are driven by the availability of food resources (Zerbini et al 2006, Anderson et al 2011, species-specific physiologies (Pillans 2006) or the need to reproduce (Bonfil et al 2005, Skomal et al 2009). …”

“…To date, it is unknown where they go and what they do when not around LEI. In addition, it is unclear how M. alfredi disperse along the eastern Australian seaboard when undertaking long-distance movements (> 300 km) and whether they commonly utilise specific migratory corridors, as observed in other species off eastern Australia (Bansemer & Bennett 2011, Smith et al 2012 and in other regions (Zerbini et al 2006, Campana et al 2011.…”

Straight as an arrow: humpback whales swim constant course tracks during long-distance migration

“…These movements, across vast areas of open ocean, occur despite a high degree of fidelity between winter calving and summer feeding grounds in many populations [3,4]. Widespread application of modern animal tracking technologies has expanded our knowledge of humpback whale migration routes, destinations and travelling speeds [5,6]. However, the mechanisms by which humpback whales navigate during these remarkable long-distance migrations remain unknown.…”