Birds' internal weather clock can sense spring

In a first, biologists have identified a key photoreceptor cell deep inside the brain of birds which takes the role of eyes in humans by directly responding to light and regulates breeding activity according to seasonal changes.

This study revealed that nerve cells existing deep inside the brains of quails, called cerebrospinal fluid (CSF)-contacting neurons, respond directly to light.

These neurons are involved in detecting the arrival of spring and thus regulate breeding activities in birds.

"The mechanism of seasonal reproduction has been the focus of extensive studies, which is regulated by photoperiod," said Takashi Yoshimura from the University of Nagoya in Japan.

"Small mammals and birds tend to breed during the spring and summer when the climate is warm and when there is sufficient food to feed their young offspring," he noted.

Light sensitive cell hidden deep in the brains of birds, responds directly to light and regulates photo biological functions.

The study was published online in the journal Current Biology.