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

Takashi Yamamoto (Arctic Environment Research Center, National Institute of Polar Research, Tokyo, Japan) and colleagues have a recent paper in the journal Marine Biology that reports on Short-tailed Shearwaters Puffinus tenuirostris visiting Arctic waters.

The paper’s abstract follows:

"The marine ecosystems of the Bering Sea and adjacent southern Chukchi Sea are experiencing rapid changes due to recent reductions in sea ice.  Short-tailed shearwaters Puffinus tenuirostris visit this region in huge numbers between the boreal summer and autumn during non-breeding season, and represent one of the dominant top predators.  To understand the implications for this species of ongoing environmental change in the Pacific sub-Arctic and Arctic seas, we tracked the migratory movements of 19 and 24 birds in 2010 and 2011, respectively, using light-level geolocators.  In both years, tracked birds occupied the western (Okhotsk Sea and Kuril Islands) and eastern (southeast Bering Sea) North Pacific from May to July.  In August–September of 2010, but not 2011, a substantial proportion (68 % of the tracked individuals in 2010 compared to 38 % in 2011) moved through the Bering Strait to feed in the Chukchi Sea.  Based on the correlation with oceanographic variables, the probability of shearwater occurrence was highest in waters with sea surface temperatures (SSTs) of 8–10°C over shallow depths.  Furthermore, shearwaters spent more time flying when SST was warmer than 9°C, suggesting increased search effort for prey. We hypothesized that the northward shift in the distribution of shearwaters may have been related to temperature-driven changes in the abundance of their dominant prey, krill (Euphausiacea), as the timing of krill spawning coincides with the seasonal increase in water temperature.  Our results indicate a flexible response of foraging birds to ongoing changes in the sub-Arctic and Arctic ecosystems.”

With thanks to Richard Phillips for information.

Short-tailed Shearwater, photograph by Kirk Zufelt

 Reference:

Yamamoto, T., Hoshina, K., Nishizawa, B., Meathrel, C.E., Phillips, R.A. & Watanuki, Y. 2014.  Annual and seasonal movements of migrating short-tailed shearwaters reflect environmental variation in sub-Arctic and Arctic waters.  Marine Biology DOI 10.1007/s00227-014-2589-1.

John Cooper, ACAP Information Officer, 26 December 2014