Ravens Remember Relationships They Had With Others

In daily life we remember faces and voices of several known individuals. Similarly, mammals have been shown to remember calls and faces of known individuals after a number of years. Markus Boeckle and Thomas Bugnyar from the Department of Cognitive Biology of the University of Vienna show in their recent article, published in Current Biology, that ravens differentiate individuals based on familiarity.

Additionally, they discovered that ravens memorize the closeness of a relationship and affiliation.

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Pigeons' Homing Skill Not Due to Iron-Rich Beak: Cells Cannot Sense Magnetic Fields

The theory that pigeons' famous skill at navigation is down to iron-rich nerve cells in their beaks has been disproven by a new study published in Nature.

The study shows that iron-rich cells in the pigeon beak are in fact specialized white blood cells, called macrophages. This finding, which shatters the established dogma, puts the field back on course as the search for magnetic cells continues.

"The mystery of how animals detect magnetic fields has just got more mysterious," said Dr David Keays who led the study.

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Birds: Divorce and Breeding Dispersal May Support the Better Option Hypothesis

Divorce and breeding dispersal in the dunlin Calidris alpina may provide support for the better option hypothesis.

Dunlins are long-lived shorebirds that often mate with the same partner over several seasons. In 126 recorded breeding attempts by dunlins, biologists Lars-Åke Flodin and Donald Blomqvist found that 23% of the pairs divorced.

They compared the breeding success of males and females before and after divorce to explore some causes and consequences of divorce.

Divorcing couples did not differ from non-divorcing couples in nest success in the season preceding divorce, both in terms of total nest failure or the number of eggs in the nest.

Non-divorcing pairs and male divorcees that paired with new partners had similar nest success in consecutive years.

However, female divorcees that found new partners doubled their nest success.

The authors concluded that female dunlins divorce to upgrade to a better mate or territory.

Bron: ScienceDaily