Bird Research News

Vol.4 No.11

Amami Woodcock

2007.11.15.

Amami-yamashigi (Jpn) Scolopax miraMorphology and classification
Classification: Charadriiformes Scolopacidae
Total length:
Wing length:
Culmen length:
Weight:Approximately 36cm
190-220mm
Tail length:70-90mm73-83mmTarsus length: 44-52mm
400-500g

Measurement values are by the author on 250 banded individual birds.

Appearance:
Male and female have the same
plumage. They are brown overallwith four lateral bands from the
top of head to the nape, a superciliary and a malar stripe, which are
all dark brown. The wing upperpart is noticeably dark, withorange-brown patterns at the edgeof the flight feathers, greater wing
coverts and tail feathers. They are Photo 1. Amami Woodcock[Photo by Kazunori Kawaless tinged with red than closely
guchi]
relatedEurasianwoodcocks
Scolopax rusticola. The bill and legs are greyish pink (Prater et al.
1997).

Vocalization:
Amami Woodcocks utter a nasal "Gwe-e" call when they fly off.
In the breeding season the male calls in a hoarse voice that sounds
like "Vu-vu" or "Geee" while flying. Juveniles call wheedlinglylike "Chee-Chee".

Distribution and Habitat
Distribution:
Amami Woodcocks are distributed on the Amami Islands, Okinawa Island and the Kerama Islands. The population is greater on
Amami Oshima, Kakeroma and Tokunoshima islands, where they
breed as a resident bird. The breeding status is unknown in areas
other than these three islands.

Habitat:
They rest in the forest of hills and the bush of lowlands during thedaytime, and forage for food in an open area, such as forest trails
and agricultural land mainly at night. They also inhabit coastal
shelterbelts or cutovers.

Life history12

3 4 5 6 7
breeding season

8 9 10 11 12
non-breeding season

Breeding system:
They seem to be polygamous or promiscuous, but the breeding
system has not been confirmed.

Nest:
They build a simple nest of fallen leaves and grass on a forest floor
that is covered with ferns in the mountains or the bushes along a
stream in the lowlands.

Eggs:
The clutch size of Amami Woodcocks on Amami Oshima Island
studied since 2006 is usually three eggs, with the range of 2 to 4.
The egg is slightly mottled on a brown ground.

24♪ http://www.bird-research.jp/1_shiryo/koe/amamiyamashigi_040312_kagoshima_kaji.mp3
Kyoko Kajimoto

Incubation and nestling periods:The female seems to exclusively carry out incubation and chickrearing. According to the observation of the two nests in Amami
Oshima Island, the eggs hatched between 20 and 30 days after they
were found. Since the incubation period of Eurasian Woodcocks is
between 21 to 24 days (Cramp 1983), the incubation periods ofboth species are assumed to be similar. The chicks of Amami
Woodcocks, which are precocial, walk about following their mother immediately after hatching. The young grow up to an adult sizein about one month, when they become independent.

Migration:
Some of the Amami Woodcocks that breed in Amami OshimaIsland and other areas may migrate south in the winter. But thistheory has not been confirmed.
Studies using transmitters and colored rings frequently showedthat some individuals left their breeding sites after August. The
juveniles have a strong tendency to move to an area away from thenatal site.

Topics of ecology, behavior and conservation● Use of various habitats
Two female Amami Woodcocks were attached with transmitters incentral Amami Oshima Island in 2005 and tracked for one year.
The females spent the winter in the secondary forest of evergreen
broad-leaved trees at an elevation of 100-150 m and came down to
the foot of the hill in the spring to breed (egg-laying, incubationand chick-rearing) (Fig. 1). After they finished raising the chicks,
they stayed in the agricultural fields of sugar cane and vegetablesin the lowlands from summer to autumn. They went back to theforested hill again in late autumn or early winter. The home rangeof these females was limited to 5-15 ha each both in the breeding
and non-breeding seasons.
Since the tracked birds were both females, it is not clear at present
whether these seasonal movements are true of the males. However,
the observation of banded birds showed that the males were more
frequently detected in the forest trails of hills from March to May
when the females started to breed. Since the display flights ofmales are frequently observed over the forest trails of hills, there isa possibility that the males, in contrast, do not move down to thefoot of hills even in the breeding season.
The study site is a forested hill-dotted plain with a variety of habitats available for the species, such as a secondary forest and agricultural land. Female
Nov-MarAmami Woodcocks
Apr-Junappear to use thesediverse habitats atwill. However, theyalso occur deep inJul-Oct
hill forests with noflat land. It is not
yet clear whether
individuals inhabit- Dec-Feb
Jun-Nov
ing these habitats
move seasonally.
The results of automobile
censuses
showed, on theMar-May
other hand, thatAmami Woodcocks
were detected more Fig. 1. Seasonal movements of the two Amami
Woodcocks attached with transmitters. Parfrequently in thetially modified from the Ministry of the Envitrails of hill forests
ronment (2005).
than in the low-

Bird Research News

Vol.4 No.11

2007.11.15.

© Japan Bird Research Association
Sumiyoshi 1-29-9, Fuchu, Tokyo, Japan

バードリサーチ生態図鑑

lands on Amami Oshima Island, but the reverse was the case on
Tokunoshima Island.
In Amami Oshima Island, the hill forest represents more than 80%of the total island area, while Tokunoshima Island, in contrast, ispredominated by the farmland with a deep hill forest in the middle.
This may mean that the species only lives in the major habitat ofits range: hill forests in Amami Oshima Island and the agriculturalland in Tokunoshima Island. A woodcock is called "Yama-shigi(mountain or woodland shorebird)" in Japanese, but it also uses
lowlands.

● Differences in appearance between Eurasian Woodcock
and Amami Woodcock
The morphological characteristics of Amami Woodcocks areusually described in a field guideas follows. Compared to Eurasian Woodcocks, 1) AmamiWoodcocks have a less pointedhead, 2) the eyes are located in
the more central region of theface, 3) the first two lateral barsof the nape are finer, 4) the eyestripe runs parallel to the malar
stripe and 5) the plumage is lesstinged with red. It is true thatsome Amami Woodcocks haveall of these distinguishing features, but both species vary
greatly from one bird to the other, which occasionally makes it
difficult to distinguish between
the two species from the appearance (Photo 2). In fact, Amami
Woodcocks are distinctly larger Photo 2: Heads of Eurasian (top)and Amami Woodcocks
and have longer and thicker legs(bottom)thanEurasian
Woodcocks,
which results in a striking difference in posture between the species. Eurasian Woodcocks stand bending forward with their heels
barely visible, while Amami Woodcocks stand more upright with
their chest high and the heels are clearly visible. In addition, Amami Woodcocks appear to fly off more clumsily from the groundand their flight distance is usually shorter.

● Impacts of exotic species and forest road on Amami
Woodcocks
The result of automobile censuses in Amami Oshima Island indicated that Amami Woodcocks were not detected in most of theareas introduced carnivores occurred (Figure 2). Mongooses Herpestes auropunctatus were introduced to control habu snakes Trimeresurus flavovirdis in the 1980s to Amami Oshima Island,
which was originally free of large carnivores. There is no doubtthat this mammal which has increased explosively in the middle
part of the island poses a major threat to Amami Woodcocks.
The mongoose control program of the Ministry of the Environment has had some effect, inhibiting the population growth ofmongooses as well as arresting their range expansion in recentyears. Instead of mongooses, however, feral cats have begun topresent a threat to Amami Woodcocks. Since feral cats are nocturnal, their activity period overlaps with that of Amami Woodcocks.
Feral cats are observed to lurk in a forest roadside gutter to attack

Fig. 2. Relationship between
the distribution of Amami Woodcocks (green)
and that ofmongooses(black).
From theMinistry of
the Environment (2006).

Amami Woodcocks. The control of feral cats will become a majorissue in the future for the conservation of rare wildlife of the Amami Islands including Amami Woodcocks.
The issue of a forest road should be also taken up for the wildlife
conservation of the islands. Large-scale deforestation has recently
become reduced as forestry declines. Forests are recovering andhabitat conditions are improving. But the forest road construction
still continues and pavement works also increase. These roads willallow feral cats and dogs easy access to the forest interior with
virgin woodlots which has not been exposed to introduced animals. In addition, paved roads will enable automobiles to move inthe forest interior at high speed. As a result, a considerable numberof Amami Woodcocks are killed every year due to automobile
accidents. Paving roads generally has a harmful effect on wildlife,
but it poses a specially serious threat to Amami Woodcocks foraging along open forest roads.

Literature
Cramp, S. (ed.) 1983. Handbook of the Birds of Europe, the Middle East andNorth Africa Volume :444-457. Oxford Univ. Press. Oxford.
Ishida, K. and Takashi, M. 1998. Estimation of relative population density andhome range of the Amami Woodcock. Strix 16:73-88. [J+E]
Ishida, K., Takashi, M., Saito, T. and Usami, E. 2003. Ten years’ changes in population and distribution of Amami Woodcocks. Strix 21:99-109. [J+E]
The Ministry of the Environment. 2005. Amami Woodcock ecological research andmonitoring report Heisei 17. [J]The Ministry of the Environment. 2006. Amami Woodcocks ecological researchand monitoring report Heisei 18. [J]Prater, AJ, Marchant, JH & Vuorinen, J. 1997. Guide to the Identification & Ageing of Holarctic Waders: 120-121. British Trust for Ornithology. Norfolk.
Languages of literature cited other than English: [J] in Japanese, [J+E] in Japanesewith English summary.

AuthorHisahiro TORIKAI NPO Amami Ornithologists' Club
Not much is known yet on thebirds in the Amami Islands.
Since there is no professional
local research institutes, I
thought I could make some
contribution as an amateur researcher. Ransacking whatbrains I have, I have investigated the Amami Woodcock in myspare time. I feel extremely
elated, when any one of themysteries are solved.
torikaih@nifty.com

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