Birds choose spring neighbors based on winter ‘friendships’

Great tits pick their spring breeding sites to be near their winter flockmates, according to new research into the social networks of birds from the University of Oxford.

The study shows that as mated pairs of great tits settle down to breed in the spring, they establish their homes in locations close to their winter flockmates. They also arrange their territory boundaries so that their most-preferred winter 'friends' are their neighbours.

Lees meer: ScienceDaily

Sparrows with unfaithful 'wives' care less for their young

A new study shows that male sparrows can judge if a spouse is prone to infidelity, providing less food for their brood if their partner is unfaithful.

Sparrows form pair bonds that are normally monogamous, but many females are unfaithful to their partner and have offspring with other males. Biologists believe that the male birds are unfaithful to ensure that they father as many chicks as they can, while females are unfaithful with males of better 'genetic quality' -- ones that are fitter and could produce stronger offspring.

Lees meer: ScienceDaily

City Birds Are Smarter Than Rural Birds

Living in the city has its advantages, it seems. That is, if you happen to be a bird.
A recently-published study, led by Jean-Nicolas Audet of McGill University, looked at the problem-solving skills of bullfinches that lived in an urban environment and compared them to those bullfinches that lived in the country.

The study took place in the island of Barbados, an ideal localization for this kind of research since the urban and rural environments are quite distinct from one another.

Lees meer: United Academics

Shrinking bird pays the bill for Arctic warming

A migratory bird has shrunk in stature as temperatures warm at its Arctic breeding ground, according to research.

As a consequence of climate change, the red knot may have a lower survival chance on a different continent, say scientists.
The shore bird breeds in the Arctic in the summer and flies to tropical habitats in winter.
Scientists believe shrinkage in body size is a response to climate change in different animals.

Lees meer: BBC 

Why Small Birds Opt For Urban Living

A few years ago, Anders Pape Møller from the University of Paris-Sud walked through the small suburban town of Orsay, France, counting all the birds he saw or heard. He walked through built-up urban areas, and through forest and farmland. He found that Orsay’s birds were congregating largely in the urban zones. He found 77 percent of them within a hundred meters of the nearest house. When he repeated the census in a similar town in Denmark, he found the same thing: 87 percent of local birds were sticking close to humans.

Lees meer: National Geographic

Dabbling ducks spread plant seeds

A new study suggests that dabbling ducks may be an important seed dispersal pathway for a very wide variety of plant species.

Dabbling ducks (of the subfamily Anatinae) are omnivorous birds that are widespread, numerous, highly mobile and often migratory, and therefore have great potential for long-distance dispersal of other organisms, including plants. However, their ability to act as plant dispersal vectors has received little attention compared to fruit- and berry-eating birds, and is often assumed to be relevant just for wetland plant species.


Lees meer: Birdwatch

European songbirds perfect their voices while wintering in Africa

New research suggests that migratory songbirds may sing during the winter months to improve their song quality ahead of the forthcoming breeding season.

A range of European songbirds are known to sing on their wintering grounds in sub-Saharan Africa. This is puzzling because singing is energetically demanding, can attract predators and takes up time that could otherwise be used to search for food.


Lees meer: Birdwatch

Ravens Know What Hidden Thieves Are Thinking

The genus Corvus contains some decidedly clever birds. Ravens, for example, have been shown to remember cheaters, those that take more than their fair share of food. Now, a new piece of research has suggested that they are also able to understand the motives of others within their group. This study, published in Nature Communications, concludes that the ability to think abstractly about the minds of others isn’t unique to primates.

Imagining what another animal is seeing is a component of the Theory of Mind (ToM) – the general ability to understand what others are thinking. This is one of the key ways that humans, chimpanzees, and monkeys operate in their own societies. A team of researchers led by the University of Vienna wanted to find out if ToM applies to ravens.

Lees meer: IFLScience

Fiendish Falcons Keep Birds Prisoner Before Eating Them

Falcons in Morocco’s Essaouira archipelago have been observed "imprisoning" other birds and holding them for several days before feeding them to their young.

The unusual behavior was observed by Abdeljebbar Qninba from Mohammed V University in Rabat, Morocco, while conducting a census of falcons on the island of Mogador in 2014, and reported in the latest edition of the journal Alauda. Among the species residing on the island is Eleonora’s falcon (Falco eleonorae), which normally eats only insects but has been known to feed on other migratory birds such as the common whitethroat, the tree pipit and others during the breeding season.

Lees meer: IFLScience

Small birds prefer flying in company

Until now, scientists had observed that some large birds are sociable amongst each other. However, a new study has confirmed that this unique characteristic can also be seen among smaller birds such as the Eurasian siskin, a bird which is able to form bonds that last for a number of years as well as travel long distances in the company of these birds. This intimacy may favour reproduction in addition to facilitating the process of adjusting to a new place.

The sociability of swans, geese and birds of the crow family has been studied and is well understood by scientists. These are large birds that tend to form stable, long-lasting bonds. This peculiarity, however, had not been observed in smaller birds, such is the case with the Eurasian siskin (Carduelis spinus). A study published in 'Bird Study' reveals that this species has a tendency to travel long distances in groups over the course of several years. Up to this time, researchers from the Natural Sciences Museum of Barcelona -the leaders of this study- had discovered that female Eurasian siskins in captivity prefer to mate with males that they know. Nevertheless, the investigators still needed to prove that these birds, when out in nature, do indeed live together for periods of time that are long enough for these specimens to interact and to get to know each other.

Lees meer: ScienceDaily

Storks shun migration for junk food

Storks feeding on rubbish dumps instead of migrating are more likely to survive the winter, research shows. 

The bird is among a growing number of migratory species that have changed their behaviour due to human influences, says an international team.
Until recently, all white storks in Europe migrated south for the winter, but now more are flying shorter distances to snack on food on dumps.

Lees meer: BBC News

Neighborhood watch and more: How reed warblers watch out when there's a cuckoo about

It's a risky business being a reed warbler. Not only do these tiny birds embark on an annual migration of some 5,000 km from their West African winter quarters to breeding grounds in the north, but they are also 'hosts' to the cuckoo, a species that lays its eggs in other birds' nests and takes no further part in raising its offspring. When the cuckoo chick hatches, it pushes the reed warbler eggs and young out of the nest. As sole occupant, it tricks its warbler 'parents' into supplying its voracious appetite until it fledges.

Cuckoos are expert tricksters: their eggs mimic those of their hosts in pattern though they are a little bigger. If the reed warbler detects an alien egg in its nest, or spots a cuckoo nearby, it may eject the odd-looking egg. But cuckoos are so swift in laying their eggs (only one is laid per nest and the process is over in as little as 10 seconds), and so clever at disguising their eggs, that warblers are often uncertain whether an odd egg in the clutch is a cuckoo egg or one of their own.

Lees meer: ScienceDaily

Successful birds keep options open

Diverse migration strategies help birds cope with environmental change, according to new research from the University of East Anglia (UEA).

Many species of migratory birds are in decline as a result of human impacts such as climate change and habitat loss. New research published today reveals why some species are more vulnerable than others and shows that species that migrate to a more diverse range of winter locations during their non-breeding season – such as White Stork, Marsh Harrier and Reed Warbler – are less likely to suffer population declines.

Lees meer: Birdwatch

Towards a new understanding of migration timing: slower spring than autumn migration in geese reflects different decision rules for stopover use and departure

Auteurs: Andrea Kölzsch, Gerhard J. D. M. Müskens, Helmut Kruckenberg, Peter Glazov,Rolf Weinzier, Bart A. Nolet, Martin Wikelski

DOI: 10.1111/oik.03121

Abstract:

According to migration theory and several empirical studies, long-distance migrants are more time-limited during spring migration and should therefore migrate faster in spring than in autumn. Competition for the best breeding sites is supposed to be the main driver, but timing of migration is often also influenced by environmental factors such as food availability and wind conditions.

Using GPS tags, we tracked 65 greater white-fronted geese Anser albifrons migrating between western Europe and the Russian Arctic during spring and autumn migration over six different years. Contrary to theory, our birds took considerably longer for spring migration (83 days) than autumn migration (42 days). This difference in duration was mainly determined by time spent at stopovers.

Timing and space use during migration suggest that the birds were using different strategies in the two seasons: In spring they spread out in a wide front to acquire extra energy stores in many successive stopover sites (to fuel capital breeding), which is in accordance with previous results that white-fronted geese follow the green wave of spring growth. In autumn they filled up their stores close to the breeding grounds and waited for supportive wind conditions to quickly move to their wintering grounds. Selection for supportive winds was stronger in autumn, when general wind conditions were less favourable than in spring, leading to similar flight speeds in the two seasons. In combination with less stopover time in autumn this led to faster autumn than spring migration.

White-fronted geese thus differ from theory that spring migration is faster than autumn migration. We expect our findings of different decision rules between the two migratory seasons to apply more generally, in particular in large birds in which capital breeding is common, and in birds that meet other environmental conditions along their migration route in autumn than in spring.