Rhinoceros Auklet Cerorhinca monocerata

posted in: Species | 0

“I took a 2 week break from all media communication and spent 10 days of this with nature in East Hokkaidō, Japan with my wife and two other friends (bird watchers).

“Much of our time was spent at the Nemuro Peninsula. This peninsula extends from the east coast of Hokkaidō and is 30km long and 8km wide; the south side faces the Pacific Ocean. There a number of islands (some uninhabited) that are located off the coast.

“One of the many birds that interested me was the Rhinoceros Auklet, which belongs to the family Alcidae (The Auks). Friesen et al (1996) (see book by Schreiber & Burger. 2002) state that the Rhinoceros Auklet is not a ‘true auklet’ and classify it under the tribe Fraterculini together with the three Puffins; the name Rhinoceros Puffin, Horn-billed Puffin or Horned Puffin has been suggested for this only extant species of the genus Cerorhinca. Although Teuri Island off the west coast Hokkaidō is credited with having the largest nesting colony

“Rhinoceros Auklet (exceeding 300,000 birds), there are 8 nesting colony sites on the Nemuro Peninsula in East Hokkaidō (Yuichi Osa, Yutaka Watanuki. 2002). We saw the birds twice, once on a short pelagic cruise and the other on an extended observation from Cape Nosappu (easternmost point of Hokkaidō & Japan). At Cape Nosappu we saw hundreds of birds, in flocks (occasionally single birds), returning in the evening with fish for juveniles. Retuning adult flew very low over the water, making spotting them difficult, as we were seeing them from a sizable distance. The flocks flew either in a straight line following each other, in a group with no order or occasionally in loose v-shaped formation. Occasionally we saw other birds with them; more on this later. Using image capture I counted 1109 birds in 90 flocks between 5.00-6.25pm on 7th June 2019 (an underestimation). The mean size of flocks was 12.3, the median 9.5 and range 1-45.

“Most work has shown nocturnal feeding of juveniles and this is suspected to be due to adult predation by raptors or kleptoparasitism by seagulls. At Cape Nosappu I did observe seagulls harassing the adults returning with food. I saw occasional birds returning with long fish that was hanging from the bill. Some work from Teuri Island (Deguchi et al 2004) suggest that the food brought back to juveniles has changed from Sardinops melanostictus (Sardine) to Engraulis japonicus (Japanese Anchovy, length ~14cm) due to availability, but Ammodytes personatus(Pacific Sandlance, length ~14cm) and Clupea (Herring, length ~25.0 cm) also needs to be considered (Gaston et al 1998). Some birds did not appear to have any fish in the bill and these could be younger adults, as birds do not breed until 3 years of age (Gaston et al 1998)

“Adult males and females are similar and have a horn at the base of the bill with two white plumes in the face, both of which are only present in the breeding season (summer).”

References
1.
EA Schreiber, Joanna Burger. Biology of Marine Birds. CRC Press 2002.
2. Yuichi Osa, Yutaka Watanuki. Status of Seabirds Breeding in Hokkaido. Journal of the Yamashina Institute for Ornithology. 2002 Vol 33 Issue 2 Pages 107-141.
3. Tomohiro Deguchi, Tomohiro Deguchi, Yutaka Watanuki, Yasuaki Niizuma, Yasuaki Niizuma, Akifumi Nakata. Interannual variations of the occurrence of epipelagic fish in the diets of the seabirds breeding on Teuri Island, northern Hokkaido, Japan. Progress In Oceanography. 2004 61(2):267-275.
4. Anthony J Gaston, Ian L. Jones, Ian Lewington. The Auks: Alcidae (Bird Families of the World). Oxford University Press. 1998.
5. Mark Brazil. Birds of Japan. Helm Field Guides 2018

Dato’ Dr Amar-Singh HSS
Ipoh, Perak, Malaysia
6-7th June 2019

Location: Nemuro Peninsula, East Hokkaidō, Japan

6+

Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.