Moon cycles and petrels... migration and mating

Dec 12, 2011
Moon cycles and petrels ... migration and mating

Creatures on Earth have annual cycles consisting of life history stages of breeding, moult and migration. For some, moon cycles influence their periodic behavior, particularly in the case of birds. New research from Université de La Réunion on Réunion, France probed the influence of photoperiod and moon phases on the migration dates and at-sea activity of Barau's petrel, a tropical seabird species, throughout its annual cycle. The study was published in the journal PLoS ONE.

A monogamous bird species, Barau's petrels (Pterodroma baraui) travel to mating sites on Ile de La Réunion to mate, synchronising their journeys with the full moon. 'First arrival at the colony is crucial in the mating system of colonial animals like seabirds,' says Patrick Pinet of Université de La Réunion, the lead author of the paper.

Contrary to some , which use either the Sun or length of the day to migrate and mate, Barau's petrel migrates longitudinally, along the equator. 'This species makes longitudinal migrations although most seabirds perform latitudinal migrations. It thus remains in the tropical zone with slight photoperiodic variations during its whole life cycle. Barau's petrel represents therefore a relevant model to study the relationships between photoperiod and the behaviour of tropical seabird species,' the authors write.

The researchers selected Barau's petrel because it exhibits a predictable annual timing of breeding and migration. These birds are more active when the full moon is out, spending more than three quarters of their time in flight rather than on the water. The researchers postulate that the increase in activity is triggered by their need to hunt for prey, something that is easier for them to do when moonlight is available.

"For the first time, bio-loggers were used to record daily the photoperiod perceived by a free-living migrant bird to study the influence of annual changes in day length on their behavior," the authors write. "The at-sea activity and migration of Barau's petrels were strongly correlated to photoperiod, suggesting a clear proximal control of these behaviours by the duration of daylight. Firstly, the annual activity of birds exhibited seasonal changes in activity according to their annual cycle with a lower proportion of time on water during the breeding compared to the non-breeding stage. The increase in ecological constraints from a growing chick across the breeding season, as regular returns to the colony and higher energetic demands, may explain the higher flight activity during this period. Secondly, dates of Barau's petrels were consistent between years and seem to be linked to photoperiod."

The team says the novel use of data loggers offers researchers the chance to study bird behavior under natural conditions. "Currently, many species are tracked around the world and cross-taxa studies could be very useful to investigate the influence of environmental cues on some fascinating behavioural decisions undertaken by free-living organisms."

Explore further: Danish museum discovers unique gift from Charles Darwin

More information: Pinet, P. et al. (2011) 'Celestial Moderation of Tropical Seabird Behavior. PLoS ONE, published 14 November. DOI:10.1371/journal.pone.0027663

add to favorites email to friend print save as pdf

Related Stories

Mysterious Fiji petrel sighting raises hopes

Sep 14, 2009

The first ever positive identification at sea of one of the world's most mysterious and endangered seabirds has raised hopes for the survival of the Fijian petrel, conservationists said Monday.

DNA confirms existence of NZ bird thought extinct

Sep 26, 2011

(PhysOrg.com) -- An examination of ancient and modern DNA by the University of Otago has confirmed that the New Zealand storm-petrel, once thought to be extinct, is a bird which continues to fly our southern ...

Recommended for you

Danish museum discovers unique gift from Charles Darwin

19 hours ago

The Natural History Museum of Denmark recently discovered a unique gift from one of the greatest-ever scientists. In 1854, Charles Darwin – father of the theory of evolution – sent a gift to his Danish ...

Top ten reptiles and amphibians benefitting from zoos

21 hours ago

A frog that does not croak, the largest living lizard, and a tortoise that can live up to 100 years are just some of the species staving off extinction thanks to the help of zoos, according to a new report.

User comments : 0