Blue Tits rely on alien invaders

Familiar British birds are learning to use an invasive wasp species as an important food source.

A team of researchers has found that Blue and Great Tits and other native birds have learnt to peck away the tips of the galls formed by the invasive Oak Marble Gall Wasp Andricus kollari and eat the protein-rich larvae inside. These, in addition to the larvae of other native gall wasps, scale insects and various other invertebrate eggs larvae and pupae, help birds survive the crucial early spring period when other food is scarce. The researchers believe that the new food source could help counteract the effects of climate change, which is causing some birds to lay their eggs too early in the year. The chicks often hatch before their main food of oak leaf-eating moth caterpillars becomes available.

Lees meer: Birdwatch Magazine

Blackbirds in the Spotlight: City Birds That Experience Light at Night Are Ready to Breed Earlier Than Their Rural Cousins

Street lamps, traffic lights and lighting from homes are causing a rise in our night-time light levels. For some time now, scientists have suspected that artificial light in our towns and cities at night could affect plants, animals and us, humans, too. Studies, however, that have tested this influence directly are few. Scientists from the Max Planck Institute for Ornithology in Radolfzell, Germany, recently investigated how light conditions in urban areas at night affect European blackbirds (Turdus merula). They found that animals exposed to low night-time light intensities, comparable to those found in cities, develop their reproductive system earlier: their testosterone levels rise and their testes mature earlier in the year. They also begin to sing and to moult earlier. The ever-present light pollution in cities may therefore exert a major influence on the seasonal rhythm of urban animals.

Lees meer: ScienceDaily

Monogamous Birds Read Partner's Food Desires

New research shows that male Eurasian Jays in committed relationships are able to share food with their female partner according to her current desire.

The behaviour suggests the potential for 'state-attribution' in these birds -- the ability to recognise and understand the internal life and psychological states of others.

The research was carried out in Professor Nicola Clayton's Comparative Cognition lab at Cambridge University's Department of Psychology, and is published February 4 in the journal PNAS.

Researchers tested mated jays and separated males from females. The females were fed one particular larvae, either wax moth or mealworm -- a treat for the birds, like chocolates -- allowing the males to observe from an adjacent compartment through a transparent window.

Once the pairs were reintroduced and the option of both larvae was presented, the males would choose to feed their partner the other type of larvae, to which she hadn't previously had access -- a change in diet welcomed by the female.

Lees meer: ScienceDaily