Visualizing danger from songbird warning calls

Japanese tit retrieves visual images of predators

Date:  January 29, 2018

Source:  Kyoto University

Summary:

A researcher finds that a small songbird, the Japanese tit (Parus minor), can retrieve a visual image of a predator from specific alarm calls.

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Kea upgraded to endangered status as predators, climate change destroy habitat

Wed, Dec 13

New Zealand's beloved Bird of the Year - the kea - could soon be no more, according to an international study.

NZ's Bird of the Year - the kea - added to global list of endangered species

Forest and Bird estimate less than 7000 kea remain.
Source: 1 NEWS

The national bird has been upgraded from 'vulnerable' to 'endangered' in BirdLife International's reassessment of birds' threat statuses for the International Union for the Conservation of Nature.

Forest and Bird chief conservation adviser Kevin Hackwell says, "Every year, kea nests are destroyed by introduced predators like rats, stoats, possums, and feral cats."

"Kea who don't regularly interact with people really benefit from large-scale aerial predator control," he says.

It follows a study which found only two per cent of kea nests were successful.

The success rate improved following the use of biodegradable 1080 by the Department of Conservation, increasing the kea nests' survival to 27 per cent in 2015.

"However, those kea that are fed by tourists and some locals tend to try novel foods, and sadly, they are particularly susceptible to eating the poison baits used to kill predators," Mr Hackwell says.

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Can bird feeders do more harm than good?

Date: December 7, 2016

Source: Central Ornithology Publication Office

Many bird lovers put out feeders full of seed for their feathered friends -- but those feeders may also attract predators that eat eggs and nestlings. The researchers behind a new study in The Condor: Ornithological Applications tried to untangle these relationships through a four-year study of songbird nests, bird feeders, and predators in urban Central Ohio.

Feeders may attract more predators to an area, but the food can also satiate predators so that they're less likely to target nests. To learn more, Jennifer Malpass of The Ohio State University and her colleagues tracked the relationships between the success of American Robin and Northern Cardinal nests, the presence of potential nest predators like squirrels, domestic cats, and other birds, and the presence of bird feeders in the area. Relationships among feeders, predators and nest survival were complex -- areas with lots of feeders had more cowbirds and crows, birds that are known to prey on songbird nests, but that didn't generally affect the success of the nests the researchers monitored.


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Predator plagues and the ongoing battle to save New Zealand's native birds

As the Department of Conservation gears up for another large pest-control operation Samantha Gee finds out if the last one worked and what the future of predator control looks like. 

A small yellow insect-eating bird with a loud melodious call is what first drew Graeme Elliott into the world of New Zealand's native birds.

Elliott, a self-confessed "nerdy little birdy kid" was raised in Christchurch and spent family holidays in Nelson where he remembers climbing Mt Arthur to look across the huge expanse of Kahurangi National Park, and wonder what was out there. 

"When I was a kid I suppose there probably was still a kakapo out there and I thought, there might be a kakapo, there might be a saddleback, there might be a kokako, they were kind of these rare and elusive creatures."

The Department of Conservation scientist says when he looks out across the second largest national park in the country now, he knows what isn't there.

Elliott paints a bleak picture of indigenous bird life in New Zealand. Without "intensive intervention" he says our native birds will continue to decline until they are extinct.

"I've always thought about the forest and the backcountry as the place where all our native animals lived and yet you realise now you go out into the Kahurangi National Park and you realise they don't live there any more, for the most part they have gone."

When he first began working with native birds in the 1980s, Elliott says there was a general acceptance that the species that were going to become extinct were already on their way out. 

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How do migrating birds avoid predators while fueling up?

Date: September 9, 2015

Source: Central Ornithology Publication Office

Summary: Birds stopping for a break during their grueling migratory flights face a difficult tradeoff: They need to fuel up with food as efficiently as possible, but they need to avoid predators while they do it. To learn more about how they make choices about food availability and predator risk, researchers spent two years capturing birds during fall migration along the coast of Maine.

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Predators predict longevity of birds, study concludes

Date:

April 30, 2014

Source:

Max-Planck-Gesellschaft

Summary:

Aging inevitably occurs both in humans and in other animals. However, life-span varies widely across species. Researchers have now found a possible general mechanism explaining differences in longevity. They investigated life history data of nearly 1400 bird species and found that avian life span varies considerably across the entire Earth, and that much of this variation can be explained by the species' body mass and clutch size and by the local diversity of predator species. The researchers were able to confirm a key prediction of the classical evolutionary theory of aging that had been proposed more than 50 years ago.

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City birds adapt to their new predators

When a bird is faced with a predator, its only objective is to escape. However, city birds do not react in the same way as their countryside counterparts, despite being from the same species. Urbanisation plays an influential role in their survival strategies. 

To study this phenomenon, Juan Diego Ibáñez-Álamo, researcher at the University of Granada (UGR) and Anders Pape Møller from Paris-Sud University (France) analysed the escape techniques of 1,132 birds belonging to 15 species in different rural and urban areas. 

Published in the Animal Behaviour journal, the results show that city birds have changed their behaviour to adapt to new threats like cats (their main predator in the city) instead of their more traditional enemies in the countryside, such as the sparrow hawk. "When they are captured, city birds are less aggressive, they produce alarm calls more frequently, they remain more paralysed when attacked by their predator and they loose more feathers than their countryside counterparts," as explained to SINC by Juan Diego Ibáñez-Álamo. The surprising thing is that urbanisation is directly linked with these differences, which become more acute the earlier the former has taken place. This suggests that escape strategies evolve alongside the expansion of cities; a concept that is on the increase worldwide.

Read more at: http://phys.org/news/2012-11-city-birds-predators.html#jCp