Follow your nose to home. Cory's Shearwaters require olfaction to find their burrows after dark

Gaia Dell'Ariccia and Francesco Bonadonna (CNRS, France) writing in the Journal of Experimental Biology have conducted experiments with Cory's Shearwaters Calonectris borealis and shown that "olfaction is the basic sensory input for homing by night even in a petrel species that is diurnally active at the colony".

The paper's abstract follows

"Olfactory cues have been shown to be important to homing petrels at night, but apparently those procellariiform species that also come back to the colony during the day are not impaired by smell deprivation.  However, the nycthemeral distribution of homing, i.e. whether displaced birds released at night return to their burrow by night or during daylight, has never been investigated.  To explore this question, we studied the homing behaviour of Cory's shearwater (Calonectris borealis) in the only known population where these birds are active at the colony both during the day and the night.  Here, we compared the nocturnal versus diurnal homing schedule of birds treated with zinc sulphate to induce a reversible but complete anosmia, to that of controls.  Our results show that anosmic shearwaters were unable to home in the dark and were constrained to wait for the daylight to find their burrow again.  Our results confirm that olfaction is the basic sensory input for homing by night even in a petrel species that is diurnally active at the colony."

Cory's Shearwaters at their burrow during the day
Photograph by Paulo Catry

Reference:

Dell'Ariccia, G. & Bonadonna, F.  2013.  Back home at night or out until morning? Nycthemeral variations in homing of anosmic Cory's shearwaters in a diurnal colony.  Journal of Experimental Biology doi: 10.1242/ jeb.082826.

NOTES:

Nycthemeral relates to the alternation of night and day.
Anosmia is the inability to perceive odour.

John Cooper, ACAP Information Officer, 20 January 2013