A subspecies of Audubon's Shearwater in the Ogasawara Islands found to be a cryptic species based on DNA analysis

Phylogenetic position of endangered Puffinus lherminieri bannermani

Kazuto Kawakami (a), Masaki Eda (b) , Hiroe Izumi (b) , Kazuo Horikoshi (c) , Hajime Suzuki (c)

(a) Department of Wildlife Biology, FFPRI, Tsukuba, Ibaraki, Japan.
(b) Hokkaido University Museum, Hokkaido University, Sapporo, Hokkaido, Japan.
(c) Institute of Boninology, Ogasawara, Tokyo, Japan.

Ornithological Science 17(1):11-18. 2018, DOI: 10.2326/osj.17.11( External link )

Puffinus lherminieri bannermani is a small black-and-white shearwater (Figure 1), which is endemic to the Ogasawara Islands, Japan. This seabird was discovered as a new species in 1915, and was called Bannerman’s Shearwater (P. bannermani). However, the classification of this seabird has changed repeatedly since then. Over a period of time, the species has been classified as a subspecies of widely distributed seabirds such as Little Shearwater (P. assimilis) and Tropical Shearwater (P. bailloni) due to similarity in their appearances. More recently, in the checklist of Japanese birds, it was treated as a subspecies of Audubon’s Shearwater P. lherminieri, which is also found in the Atlantic and Indian Oceans, and the nomenclature “Bannerman’s Shearwater” was rejected. However, there was a lack of scientific evidence for this change, and the phylogenetic relationship of this seabird with other seabirds was shrouded in mystery.

This Ogasawara group of the shearwater was reported to breed on Kitaiwoto Island before World War II, but no colonies were found after the war. In 2007, there were finally confirmatory sightings of its colonies in the forests of Minamiiwoto and Higashijima, two small uninhabited islands. However, this shearwater is highly vulnerable to rat predation and deterioration of nesting environments by alien scrub Leucaena leucocephala, and the seabirds are now classified as endangered by Japan’s Ministry of the Environment.

A DNA analysis of this seabird was conducted by the Forestry and Forest Products Research Institute in collaboration with Hokkaido University and the non-profit Institute of Boninology. Results from the DNA analysis of this seabird group residing in Ogasawara were compared with those of the shearwater species found in various parts of the world. The results indicated that this seabird group residing in Ogasawara has a completely different phylogenetic lineage compared with birds such as P. assimilis and P. lherminieri and appears to be a group of unique seabird species (Figure 2). The Ogasawara population should be split from the Audubon’s Shearwater, and the monotypic Bannerman’s Shearwater is recommended to be restored to a distinct species. This is comparable with the discovery of a novel species; the revelation of a hidden endemic species at the Ogasawara World Natural Heritage site should greatly increase the acknowledged environmental value of the area. Much remains unknown about the ecology and distribution of this seabird; thus, there is a need to conduct further research with the goal of conservation in mind.

Glossary

1) Puffinus lherminieri bannermani of the Ogasawara Islands.
Length of about 30 cm, wingspan of approximately 70 cm. Diminutive shearwater with black dorsal and white ventral coloration. They are breeding in the shrub forests of Ogasawara.

2) Higashijima Island
Lies immediately in the east of Chichijima Island. Removal of invasive plants is underway by the Forestry Agency for restoration of habitats for seabirds and other species. The only known island where nests of Bryan’s Shearwater (P. bryani), species as rare as P. lherminieri, are found.
Reference: “Finally found! Bryan’s Shearwater nesting area - mysterious rare birds that survive in the Ogasawara's national forests.” (March 24, 2015 press release).

Figure 1. Puffinus lherminieri bannermani of the Ogasawara Islands.
Image of breeding area on Minamiiwoto.

Figure 2. Phylogenetic relationships of P. lherminieri bannermani with other small black-and-white shearwater species. The scientific name (specific name) for each species is provided.