How puffins catch food outside the breeding season

JULY 10, 2019

by University of Liverpool

Little is known about how seabirds catch their food outside the breeding season but using modern technology, researchers at the University of Liverpool and the Centre for Ecology & Hydrology have gained new insight into their feeding habits.

Seabirds, including puffins, are often elusive and spend much of their lives at sea, feeding exclusively there. The period outside of the summer breeding season is particularly mysterious as the birds spend their time far away from land.

Using depth recorders, researchers compared the feeding behaviour of puffins with two closely related species, guillemots and razorbills, to find out how deep and how long they dive for during the non-breeding period.

They also fitted loggers to seabirds breeding on the Isle of May National Nature Reserve in south-east Scotland. These birds were then recaptured the following breeding season, when they returned to land again after months away at sea.

Puffins are excellent divers and, in a similar way to penguins, use their wings to "fly" underwater to catch their prey.

Yet the study found that despite this great diving ability, both common guillemots and razorbills can dive for even deeper and longer than puffins can and continue to do so outside the breeding season.

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Dive-bombing cormorant: Bird yanks suckerfish right off a whale shark's skin

BY SARAH KEARTES JANUARY 31 2018

Fishing is time-consuming business, so diving birds in Mexico's Baja California are frequenting the local "sushi conveyor" instead. That conveyor comes in the hulking shape of the region's reigning big fish: the whale shark. The crafty cormorants have figured out that the giant sharks provide an endless supply of remora sashimi.

In the clip, a diving cormorant yanks furiously at a remora fish attached to the skin of a passing whale shark, before finally pulling its meal free. It's a truly remarkable sighting – in fact, this footage filmed back in 2012 may be the first (and only) example of its kind. According to marine biologist Dr Simon Pierce, who has done extensive work on whale sharks, experts have been excitedly discussing the video since it started making the rounds online earlier this week.

"It's super cool!" he says. "I don't think it's been documented. I've never seen or heard of it previously, but that particular cormorant certainly knew what it was doing. Smart bird!"

Continued and watch video  

Feeding strategies in competing hummingbird species observed in a small area in Brazil

Scientists observed and reported various types of behavior at the area having placed artificial feeders with variable in concentration sugar-water solutions

Date: May 2, 2017

Source: Pensoft Publishers

Being the vertebrates with the highest metabolic rate thanks to their rapid wing flaps, the hummingbirds have evolved various types of feeding behaviour. While the nectar-feeders tend to go for food high in energy, strong competition affects greatly their preferences and behaviour towards either dominance, subordination, a strategy known as trapline and a fourth one named hide-and-wait, conclude the Brazilian scientists Lucas L. Lanna, Cristiano S. de Azevedo, Ricardo M. Claudino, Reisla Oliveira and Yasmine Antonini of Universidade Federal de Ouro Preto. Their conclusions following six months of observations in an Atlantic Forest remnant in southeastern Brazil are published in the open access journal Zoologia.

To test previous assumptions as well as their own hypotheses, the researchers placed artificial bird feeders filled with variable in concentration sugar-water solutions across four separate patches at the core of the forest fragment.

The scientists sought to find out whether the birds would show clear preference for the most sugary food source; whether larger size and heavier weight would guarantee better access to the most nutritious feeders; what strategies would be adopted by each species; and which ones would prove the dominant and most aggressive.

As expected, the scientists concluded that the birds prefer the most sugar-dense solutions. However, when subordinate species, such as the white-throated hummingbird and the versicoloured emerald, confronted dominant species guarding the most nutritious food sources, they would be either frightened or expelled following a short chase. Subsequently, these hummingbirds would resort to the feeders with low-sugar solutions.

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Bird Buffet Requires Surveillance: Sandpipers Exhibit Different Feeding Behavior Depending On Position in Group

Oct. 28, 2013 — The behaviour of semipalmated sandpipers (Calidris pusilla) feeding during low tide in the Bay of Fundy, New Brunswick, surprised Guy Beauchamp, an ornithologist and research officer at the University of Montreal's Faculty of Veterinary Medicine. While individuals on the periphery remained alert and used short pecks to feed on the mudflats, birds in the middle of the group relaxed their vigilance and fed on a different resource. The more peripheral group members were effectively used as sentinels for the others.

Two observation seasons were needed to confirm this never-before-documented behaviour. The phenomenon attracted the attention of Britain's Royal Society, which has just published the results of Beauchamp's research in the most recent edition of its Biology Letters. "Both foraging modes are easy to distinguish," Beauchamp explained. "In the first case, the birds keep their heads upright while pecking at their food rapidly; they are on the lookout for predators. In the second case, their heads are kept low while they scrape the mud in search of tiny organisms."

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