The Committee of the World Heritage Convention (formally the Convention Concerning the Protection of the World Cultural and Natural Heritage, adopted in 1972) has added the Archipiélgo de Revillagigedo (Revillagigedo Islands), a group of four Mexican islands in the eastern Pacific Ocean, as a natural Site to the World Heritage List under Criteria (vii), (ix) and (x) during its 40th Session in Istanbul, Turkey this month (click here).

The island group is home to the endemic and Critically Endangered Townsend’s Shearwater Puffinus auricularis, now restricted to Socorro Island, and to small populations of ACAP-listed and Near Threatened Laysan Albatrosses Phoebastria immutabilis on Clarión and San Benedicto Islands.

A Laysan Albatross hatches its egg on Clarión Island, photograph by Ross Wanless

The Reserva de la Biosfera Archipiélgo de Revillagigedo was established in 1994 and was designated as a Ramsar Wetland Site of International Importance (No. 1537) in 2004.

John Cooper, ACAP Information Officer, 20 July 2016

Richard Phillips (British Antarctic Survey, Madingley Road, Cambridge, UK) and colleagues involved with the Albatross and Petrel Agreement have reviewed the conservation of albatrosses and large petrels in the journal Biological Conservation.

The paper’s abstract follows:

“Seabirds are amongst the most globally-threatened of all groups of birds, and conservation issues specific to albatrosses (Diomedeidae) and large petrels (Procellaria spp. and giant petrels Macronectes spp.) led to drafting of the multi-lateral Agreement on the Conservation of Albatrosses and Petrels (ACAP). Here we review the taxonomy, breeding and foraging distributions, population status and trends, threats and priorities for the 29 species covered by ACAP. Nineteen (66%) are listed as threatened by IUCN, and 11 (38%) are declining. Most have extensive at-sea distributions, and the greatest threat is incidental mortality (bycatch) in industrial pelagic or demersal longline, trawl or artisanal fisheries, often in both national and international waters. Mitigation measures are available that reduce bycatch in most types of fisheries, but some management bodies are yet to make these mandatory, levels of implementation and monitoring of compliance are often inadequate, and there are insufficient observer programmes collecting robust data on bycatch rates. Intentional take, pollution (including plastic ingestion), and threats at colonies affect fewer species than bycatch; however, the impacts of disease (mainly avian cholera) and of predation by introduced species, including feral cats (Felis catus), rats (Rattus spp.) and house mice (Mus musculus), are severe for some breeding populations. Although major progress has been made in recent years in reducing bycatch rates and in controlling or eradicating pests at breeding sites, unless conservation efforts are intensified, the future prospects of many species of albatrosses and large petrels will remain bleak.”

Atlantic Yellow-nosed Albatross, photograph by Peter Ryan

With thanks to Richard Phillips.

Reference:

Phillips, R.A., Gales, R., Baker, G.B., Double, M.C., Favero, M., Quintana, F., Tasker, M.L., Weimerskirch, H,. Uhart, M. & Wolfaardt, A.[C.] 2016.  The conservation status and priorities for albatrosses and large petrels.  Biological Conservation 201: 169-183.

John Cooper, ACAP Information Officer, 19 July 2016

Masaki Eda (Hokkaido University Museum, Hokkaido University, Sapporo Hokkaido, Japan) and colleagues have an accepted article published online in the journal Ibis that shows that birds from two populations of Short-tailed Albatrosses Phoebastria albatrus tend to mate assortatively.

The paper's abstract follows:

“Assortative mating is an important pre-mating isolation mechanism that has been observed in some wild populations of seabirds.  The Short-tailed Albatross Phoebastria albatrus is a globally Vulnerable seabird that breeds mainly on Torishima and the Senkaku Islands in the north-western Pacific Ocean.  Ourtr previous studies suggested that two genetically distinct populations exist, one on Torishima and the other on the Senkaku Islands.  Recently, however, several un-ringed birds in subadult plumage have been observed breeding on Torishima in the Hatsunezaki colony.  Since almost all birds hatched on Torishima since 1979 have been ringed, the natal site of the un-ringed birds was suspected to be the Senkaku Islands.  Genetic differences between the two populations would reveal the natal sites of un-ringed birds. By observing the ring status (ringed or un-ringed) of mating pairs and analysing the mitochondrial DNA (mtDNA) control region 2 of un-ringed birds, we assessed whether birds that originated from Torishima and the Senkaku Islands achieved pre-mating isolation.  There was a small number of pairs on Torishima that comprised one ringed and one un-ringed bird, but the observed number was significantly lower than that expected if ringed and un-ringed birds mated randomly.  Furthermore, mtDNA analyses of nine un-ringed birds demonstrated that all belonged to a particular haplotype clade from the Senkaku Islands.  These results show that birds from Torishima and the Senkaku Islands mate assortatively but that there is incomplete pre-mating isolation between birds from the two island groups.  The pre-mating isolation of these two populations of Short-tailed Albatross could arise from differences in the timing of breeding and incompatibility in mating displays.  Since the divergence between the two populations is unlikely to be sufficient to achieve complete post-mating isolation, the two groups are likely to be hybridising.  Further studies using molecular and/or behavioural analyses would be required to reveal the evolutionary significance of hybridisation between these two populations.”

With thanks to Barry Baker.

Short-tailed Albatross, photograph by Hiroshi Hasegawa

Reference:

Eda, M., Izumi, H., Konno, S., Konno, M.& Sato, F. 2016.  Assortative mating in two populations of Short-tailed Albatross Phoebastria albatrus on Torishima.  Ibis doi: 10.1111/ibi.12397.

John Cooper, ACAP Information Officer, 18 July 2016

Johan Elmberg (Division of Natural Sciences, Kristianstad University, Sweden) and colleagues have published in the journal Marine Ornithology on the passage of seabirds, including the ACAP listed and Critically Endangered Balearic Shearwaters Puffinus mauretanicus, past a Portuguese headland.

The paper’s abstract follows:

“Land-based counts of migrating seabirds remain essential to increase knowledge about their numbers and movements.  To assess the value of Cabo Carvoeiro (Peniche, Portugal) as a monitoring site in the East Atlantic, we studied seabird species composition, passage patterns and flock size during mid-October 2014.   During standardized counts, we observed nearly 8000 seabirds of 17 species. The ratio of individuals passing in a southerly to southwesterly direction was >96% in all species, showing that genuine migrants were counted. The passage rate (birds/hour) was higher for Northern Gannets Morus bassanus than for any other species, by a factor of approximately 50 (morning mean 906/h, afternoon mean 1153/h).  The globally endangered Balearic Shearwaters Puffinus mauretanicus, Great Skuas Stercorarius skua and Pomarine Skuas S. pomarinus had passage rates of 10–25/h.  Flock size distribution in the 11 most numerous species showed that most migrated singly or in groups of two.  Flock size was larger in Balearic Shearwaters than in both Cory’s Calonectris borealis and Manx Shearwaters P. puffinus.  Among skuas, flock size was larger in Pomarine than in Great Skuas.  The passage rate of Manx Shearwaters was positively correlated with that of Northern Gannets, Great Skuas and Sandwich Terns Sterna sandvicensis.  Northern Gannets showed a positive co-variation with Pomarine Skuas. Balearic and Sooty Shearwaters Ardenna griseus [=grisea]were the only species that did not show any significant co-variation with another species. Morning and afternoon passage rates did not differ significantly in any of the six most numerous species (Northern Gannets, Cory’s and Balearic Shearwaters, Great and Pomarine Skuas, and Sandwich Terns), or in Sooty Shearwaters (less numerous).  Thus, the passage rates at Cabo Carvoeiro in October of Balearic Shearwaters and five other species were as high or higher than those reported from any other seawatch in Portugal, indicating the international value of seabird monitoring at Cabo Carvoeiro during the autumn migration.”

Balearic Shearwater at sea, photograph by Pep Arcos

Reference:

Elmberg, J., Hirschfeld, E., Cardoso, H. & Hessel, R. 2016.  Passage patterns of seabirds in October at Cabo Carvoeiro, Portugal, with special reference to the Balearic Shearwater Puffinus mauretanicus.  Marine Ornithology 44: 151-156.

John Cooper, ACAP Information Officer, 12 July 2016