18 research outputs found
Excesso de Confianna na Elaboraaao do Orramento: Uma Annlise da Produuuo Cienttfica nos Periidicos Internacionais entre 2005 e 2009 (Overconfidence in Budgeting: An Analysis of the Scientific Production in International Journals between 2005 and 2009)
Phenotype analysis of unstimulated lymphocytes and anti-cd3-stimulated proliferating t-cells from cerebrospinal fluid and peripheral blood in patients with multiple sclerosis and other neurological diseases
Immediate effects of neurodynamic nerve gliding versus static stretching on hamstring neuromechanical properties
Movement and diving of killer whales ( Orcinus orca ) at a Southern Ocean archipelago
Eleven satellite tagswere deployed on 9 killerwhales at the Prince Edwards Islands in the Southern Ocean. Statespace
switchingmodelswere used to generate position estimates fromArgos location data,while two behavioural
modes were estimated from the data.
Individuals were tracked for 5.6–53.2 days, duringwhich time they moved 416–4470 km (mean 82.7 km day−1)
but 69% of position estimates were within the 1000 m depth contour around the islands (b35 km from the tagging
site). Killerwhales showed restricted behaviour close to the islands, particularly inshorewhere they can effectively
hunt seals and penguins, and at seamounts to the north of the islands.
Generalised linear mixed effect models were used to explore the relationship between environmental variables
and behavioural mode. The best model included depth, sea surface temperature, latitude, sea surface height
anomaly and bottomslope, but killerwhales did not clearly target features such as fronts and apparentmesoscale
eddies. Killer whales showed restricted behaviour in shallow water, at high latitudes and low sea surface
temperature — the conditions characterising the archipelago.
Dive data fromtwo individuals largely revealed shallow dives (7.5–50mdeep), but deeper dive bouts to around
368mwere also recorded. Diveswere significantly deeper during the day and maximumdive depthswere 767.5
and 499.5 m, respectively. This suggests that killer whales might also prey on vertically migrating cephalopods
and perhaps Patagonian toothfish.
Three individuals made rapid and directed long-distance movements northwards of the islands, the reasons for
which are speculative.National Research Foundation’s (NRF) Thuthuka, South African National Antarctic programmes, the South African Department of Science and Technology through the NRF, the Mohamed bin Zayed Species Conservation Fund (Project number: 10251290) and the International Whaling Commission’s Southern Ocean Research Partnership.http://www.elsevier.com/locate/jembe2016-12-31hb201