Foraging behaviour of four albatross species by night and day

first_imgWe integrated information from satellite transmitters, GPS loggers and wet/dry activity loggers to compare the at-sea behaviour of 4 sympatric albatross species by night and day: wandering Diomedea exulans, grey-headed Thalassarche chrysostoma, black-browed T melanophrys and light-mantled sooty Phoebetria palpebra ta (in total, 350 foraging trips by 10 1 individuals). Trip duration, distance and maximum range varied more within species between stages (incubation, broodguard and post-brood) than between species at the same stage, implying that reproductive constraints are more important than interspecific competition in shaping foraging behaviour. Wandering albatrosses spent more time on the water in fewer, longer bouts than other species. The proportion of time spent on the water was similar among the 3 smaller species. The partitioning of foraging activity between day and night varied little between species: all landed and took off more often, but spent less time overall on the water during the day than at night. This supports observations that albatrosses forage most actively during daylight, even though many of their fish and squid prey approach the surface only at night. Albatrosses were more active on bright moonlit nights, seem to have no fixed daily requirement for sleep, rest or digestion time on the water, can navigate in darkness, and are probably unhindered by the slight reduction in mean wind strength at night. They are probably less active at night because their ability to see and capture prey from the air is reduced and it is then more energy-efficient for them to rest or to catch prey using a ‘sit-and-wait’ foraging strategy.last_img read more

US, Portuguese Defence Leaders Talk Cooperation

first_img US, Portuguese Defence Leaders Talk Cooperation View post tag: News by topic View post tag: Navy View post tag: Portuguese View post tag: talk April 1, 2014 Back to overview,Home naval-today US, Portuguese Defence Leaders Talk Cooperation View post tag: US View post tag: Defence View post tag: Naval View post tag: leaders View post tag: Cooperation Authorities U.S. Defense Secretary Chuck Hagel welcomed yesterday Portuguese Minister of Defense Jose Pedro Aguiar-Branco to the Pentagon, and expressed to the minister his appreciation for Portugal’s many contributions to international security, Pentagon Press Secretary Navy Rear Adm. John Kirby said in a Defense Department news release. The secretary specifically thanked Portugal for supporting NATO’s Baltic Air Policing rotation later this year, and Portugal’s support in combating piracy and maritime crime in the Gulf of Aden and off Somalia, Kirby said in the release.Kirby said Hagel also thanked Aguiar-Branco for Portugal’s hospitality towards U.S. airmen at Lajes Field.The two leaders “discussed the situation in Ukraine and reaffirmed both nations’ steadfast commitment to our collective defense obligations,” Kirby said.Both men, he said, agreed on the need for Russia to begin discussions with the Ukrainian government, as diplomacy remains the only acceptable means of resolving this crisis.“Secretary Hagel looks forward to seeing Minister Aguiar-Branco at the NATO Summit in Wales, this September,” Kirby said in the release.[mappress]Press Release, April 1, 2014, Image: US DoD View post tag: Defense Share this articlelast_img read more