Bird Bits

Teamwork

Bird couples may work together to decrease predation at their nest. In a behavior called “coordinated misdirection,” both adults will initially fly toward their nest but one will veer off while the other goes directly to the nest. Scientists believe that nest predators are distracted by the bird in flight. This means it’s less likely that the predator will discover the nest entrance itself. The behavior has been shown in at least 28 species of passerine birds, across 5 distinct families.

Eric R. Gulson-Castillo, Harold F. Greeney, and Benjamin G. Freeman (2018) Coordinated misdirection: a probable anti-nest predation behavior widespread in Neotropical birds. The Wilson Journal of Ornithology In Press

Evaluating Expected Outcomes 

In a clever set of experiments, birds in the parrot family learned that they could exchange a token for food. Later, they were given a choice between a token or a piece of food. 

If the token allowed the parrots to get preferred food in the future, the subjects would select the token. “This ability is considered cognitively challenging because it not only requires inhibiting impulses, but also evaluating expected outcomes in order to decide whether waiting is worthwhile.” Previously, this type of behavior had been demonstrated in primates but not in bird species.

Krasheninnikova, A.; Höner, F.; 
O’Neill, L.; Penna, E.; von Bayern, A. M. P. (2018) Economic decision-making in parrots. Scientific Reports 8, 12537

 

Birds Can See Earth’s Magnetic Fields, And Now We Know How That’s Possible

From sciencealert.com by Michelle Star

The mystery behind how birds navigate might finally be solved: it’s not the iron in their beaks providing a magnetic compass, but a protein in their eyes that lets them “see” Earth’s magnetic fields. These findings come courtesy of two papers—one studying robins, the other zebra finches. The fancy eye protein is called Cry4, and it’s part of a class of proteins called cryptochromes—photoreceptors sensitive to blue light, found in both plants and animals. These proteins play a role in regulating circadian rhythms. There’s also been evidence in recent years that, in birds, the cryptochromes in their eyes are responsible for their ability to orient themselves by detecting magnetic fields, a sense called magnetoreception.

FMI: sciencealert.com/birds-see-magnetic-fields-crypto-chrome-cry4-photoreceptor-2018