Diego Rubolini (Dipartimento di Bioscienze, Università degli Studi di Milano, Italy) and colleagues have published in the journal Ethology on colony attendance and foraging activity in Scopoli's Shearwaters Calonectris diomedea in relation to moonlight.

The paper’s abstract follows:

“Moonlight is known to affect the nocturnal behaviour and activity rhythms of many organisms.  For instance, predators active at night may take advantage from increased visibility afforded by the moon, while prey might regulate their activity patterns to become less detectable.  Many species of pelagic seabirds attend their colony only at night, in complete darkness, avoiding approaching their nest sites under moonlight.  This behaviour has been most often interpreted as an antipredator adaptation (‘predation avoidance’ hypothesis).  However, it may also reflect a lower foraging efficiency during moonlit nights (‘foraging efficiency’ hypothesis).  Indeed, moonlight may reduce prey availability because preferred seabird prey is known to occur at higher depths in moonlit nights.  Using high-accuracy behavioural information from data loggers, we investigated the effect of moonlight on colony attendance and at-sea nocturnal foraging in breeding Scopoli's shearwaters Calonectris diomedea.  We found that birds departing for self-feeding trips around the full moon performed longer trips than those departing around the new moon.  On nights when the moon was present only partly, nest burrow entrances took place largely in the moonless portion of the night.  Moreover, contrary to predictions from the ‘foraging efficiency’ hypothesis, nocturnal foraging activity increased according to moonlight intensity, suggesting that birds increased their foraging activity when prey became more detectable.  This study strengthens the idea that colony attendance behaviour is strictly controlled by moonlight in shearwaters, which is possibly related to the perception of a predation risk.”

Scopoli's Shearwater fledgling, photograph from BirdLife Malta

Reference:

Rubolini, D., Maggini, I., Ambrosini, R., Imperio, S., Paiva, V.H., Gaibani, G., Saino, N. & Cecere, J.G. 2014.  The effect of moonlight on Scopoli's Shearwater Calonectris diomedea colony attendance patterns and nocturnal foraging: a test of the foraging efficiency hypothesis.  Ethology DOI: 10.1111/eth.12338.

John Cooper, ACAP Information Officer, 30 December 2014

The Limahuli Preserve on the northern coast of the Hawaiian island of Kaua’i is managed by the National Tropical Botanical Garden, a USA not-for-profit institution.  The Garden’s mission is to “enrich life through discovery, scientific research, conservation, and education by perpetuating the survival of plants, ecosystems, and cultural knowledge of tropical regions”.  The preserve was acquired in 1994.

The Upper Limahuli Preserve encompasses approximately 400 acres (1.6 km²) of land above Limahuli Falls in a valley with precipitous sides which extends from about 500 m to 1000 m at the summit of Hono O Napali.  The vegetation ranges over altitude from lowland to montane rain forest.  Because of its remoteness it is only accessed via helicopter.  “Since 1992, staff has increased management activities in this remote area in an effort to mitigate the decline of this once pristine ecosystem. Restoration and management programs today are focusing on control of the worst of the invasive plant species and control of the feral pigs [Sus scrofa].”

A 8-km ridgeline fence was erected around the preserve in 2009 to keep pigs and goats away from the native and endemic plants.  The fence is also proving to be a major boon in keeping pigs away from the preserve’s breeding colonies of Endangered Newell’s Shearwaters Puffinus newelli and Vulnerable Hawaiian Petrels Pterodroma sandwichensis, with 2013 proving to have the highest breeding success since observations by the Kauai Endangered Seabird Recovery Project (KESRP) commenced in 2006.  However, the large-mesh fence is not a barrier to feral cats Felis catus and rodents such as Black Rats Rattus rattus (although control operations against rats are practiced).  Regular visits to the site are made by helicopter to the preserve to maintain the fence.

Newell's Shearwater on Kaua'i, photograph by Eric Vanderwerf

The KESRP collects data annually on breeding success, reasons for failure (such as predation of chicks by cats) and site fidelity of banded shearwaters and petrels within the preserve (and within the nearby 14.5- km² Hono o Na Pali Natural Area Reserve).  Burrows are monitored using burrow scopes and remote cameras.  Monitoring of the shearwater on the island has revealed a decreasing population.

The Kauai Endangered Seabird Recovery Project is a collaboration of the Hawai‘i Department of Land and Natural Resources, the U.S. Fish and Wildlife Service and the University of Hawai‘i’s Pacific Cooperative Studies Unit.

Click here for more news on Newell's Shearwater.

With thanks to Andre Raine, Kauai Endangered Seabird Recovery Project and Kawika Winter, National Tropical Botanical Garden, for information.

Selected Literature:

Day, R.H., Cooper, B.A. & Telfer, T.C. 2003.  Decline of Townsend's (Newell's) Shearwaters (Puffinus auricularis newelli) on Kauai, Hawaii.  Auk 120: 669-679.

Department of Land and Natural Resources 2011. Hono O Nā Pali Natural Area Reserve (NAR) Management Plan.  Honolulu: Department of Land and Natural Resources.  107 pp.

Duffy, D. C. & Capece, P.I. 2014.  Depredation of endangered burrowing seabirds in Hawai’i: management priorities.  Marine Ornithology 42: 149-152.

Griesemer, A.M. & Holmes, N.D. 2011.  Newell's Shearwater population modeling for habitat conservation plan and recovery planning.  Pacific Cooperative Studies Unit Technical Report No. 176.  68 pp.

Troy, J.R., Holmes, N.D., Veech, J.A., Raine, A.F. & Green, M.C. 2014.  Habitat suitability modeling for the Newell's Shearwater on Kauai.  Journal of Fish and Wildlife Management  doi: http://dx.doi.org/10.3996/112013-JFWM-074.

John Cooper, ACP Information Officer, 29 December 2014

Samantha Patrick and Henri Weimerskirch (Centre d'Etudes Biologiques de Chizé, Villiers-en-Bois, France) have published in the Proceedings of the Royal Society B on the effects of personality on breeding in Wandering Albatrosses Diomedea exulans.

The paper’s abstract follows:

“Studies are increasingly demonstrating that individuals differ in their rate of ageing, and this is postulated to emerge from a trade-off between current and future reproduction.  Recent theory predicts a correlation between individual personality and life-history strategy, and from this comes the prediction that personality may predict the intensity of senescence.  Here we show that boldness correlates with reproductive success and foraging behaviour in wandering albatrosses, with strong sex-specific differences.  Shy males show a strong decline in reproductive performance with age, and bold females have lower reproductive success in later adulthood.  In both sexes, bolder birds have longer foraging trips and gain more mass per trip as they get older.  However, the benefit of this behaviour appears to differ between the sexes, such that it is only matched by high reproductive success in males.  Together our results suggest that personality linked foraging adaptations with age are strongly sex-specific in their fitness benefits and that the impact of boldness on senescence is linked to ecological parameters.”

Click here for a related paper by the same authors and also here for a popular article on their work..

Wandering Albatross: bold or shy?  Photograph by Genevieve Jones

Reference:

Patrick, S.C & Weimerskirch, H. 2015,  Senescence rates and late adulthood reproductive success are strongly influenced by personality in a long-lived seabird.  Proceedings of the Royal Society B 292.  2014 doi:10.1098/rspb.2014.1649.

John Cooper, ACAP Information Officer, 28 December 2014

Gonzalo Arroyo (Fundación Migres, Cadiz, Spain) and colleagues have come up with a new estimate of the numbers of ACAP-listed  Shearwaters Puffinus mauretanicus based on counts of migrating birds, publishing in the journal Bird Conservation International.

“The Balearic Shearwater Puffinus mauretanicus is considered one of the most threatened seabirds in the world, with the breeding population thought to be in the range of 2,000–3,200 breeding pairs, from which global population has been inferred as 10,000 to 15,000 birds.  To test whether the actual population of Balearic Shearwaters is larger than presently thought, we analysed the data from four land-based census campaigns of Balearic Shearwater post-breeding migration through the Strait of Gibraltar (mid-May to mid-July 2007–2010).  The raw results of the counts, covering from 37% to 67% of the daylight time throughout the migratory period, all revealed figures in excess of 12,000 birds, and went up to almost 18,000 in two years.  Generalised Additive Models were used to estimate the numbers of birds passing during the time periods in which counts were not undertaken (count gaps), and their associated error.  The addition of both counted and estimated birds reveals figures of between 23,780 and 26,535 Balearic Shearwaters migrating along the north coast of the Strait of Gibraltar in each of the four years of our study.  The effects of several sources of bias suggest a slight potential underestimation in our results.  These figures reveal the urgent need to reformulate the population viability analysis for the species, and then if necessary reconsider its conservation status.”

Balearic Shearwater at sea

Reference:

Arroyo, G.M., Mateos-Rodríguez, M., Muñoz, R., De La Cruz, A., Cuenca, D.& Onrubia, A. 2014.  New population estimates of a critically endangered species, the Balearic Shearwater Puffinus mauretanicus, based on coastal migration counts.  Bird Conservation International  DOI: http://dx.doi.org/10.1017/S095927091400032X http://dx.doi.org/10.1017/S095927091400032X.

John Cooper, ACAP Information Officer, 27 December 2014