羽山 伸一

A helminthological survey on the Japanese macaques (Macaca fuscata) in the Shimokita Peninsula, Aomori Prefecture, Japan, was performed. Among 100 macaque individuals, 3 hehninth species, namely, Ogmocotyle ailuri, Strongyloides fuelleborni and Trichuris sp., were obtained. Especially, S. fuelleborni and T. sp. are common species in the macaque individuals examined, but they could be regarded as agents of zoonotic helminthiasis, the occurrence should be cautious. Although Streptopharagus pigmentatus and Oesophagostomum aculeatum are common nematodes in the macaques, both species were not obtained from the present individuals. And, the relationships between the occurrence/incidence of the parasitic helminths and host age were not statistically significant

鳥類への負担が最小限となるような雌雄の判別方法を確立するため，日本産鳥類11目42種の糞からDNAを抽出し，雌雄の判別を試みた．標的遺伝子として，性判別で有効であると報告されているspindlin，EE0.6，CHD領域を用いて，種ごとにプライマー等の条件を変えてpolymerase chain reaction （PCR）を行った．結果として，一部には増幅が確認できない種や検体が見受けられたものの，10目36種で雌雄に特異的な遺伝子領域の増幅が確認された．増幅が確認できなかった検体に関しては，性判別にもちいる糞を，抽出操作の前で十分に選定する作業が求められる．増幅が確認された検体の内，その内9種においては検体数と増幅した割合から，性判別に本研究の方法が実用的であることが判断できた．幼鳥から採取した糞からも性判別が可能であることからも，鳥類への負担が従来の方法と比較して少ないだけでなく，より判別可能条件が広い方法であることが示唆された．

© 2016 Japanese Association for Laboratory Animal Science. Several drug-metabolizing cytochrome P450 (CYP) enzymes exhibit sexual dimorphism depending on the pituitary growth hormone (GH) secretory patterns. However, the mechanism underlying CYP sexual dimorphism remains unclear. We previously established a transgenic (Alb- DsRed2 Tg) rat that expressed red fluorescent DsRed2 protein, particularly in hepatocytes, to visualize cell differentiation and multiplication and found that hepatic DsRed2 expression exhibited sexual dimorphism that was limited to adult males. In this study, we compared the expression patterns between sexual dimorphic Cyps and DsRed2 in Tg rats after experimentally reversing the GH secretory patterns in males and females. Postnatal day 1 male and female Tg rats were gonadectomized and then testosterone propionate (0.25 mg/rat) was subcutaneously administered to ovariectomized females immediately after surgery. Cyp mRNA and DsRed2 expression levels were quantified using RT-PCR and an in vivo imaging system, respectively. GH-dependent Cyps and hepatic DsRed2 expression patterns were reversed in males and females at 9 weeks after birth and were significantly correlated (P<0.05). This suggested that DsRed2 expression in these Tg rats depended on GH secretory patterns. Based on DsRed2 fluorescence, this Tg rat model could become a tool to readily and effectively evaluate changes in GH-dependent Cyp expression.

© 2014 Macmillan Publishers Limited. In April 2012 we carried out a 1-year hematological study on a population of wild Japanese monkeys inhabiting the forest area of Fukushima City. This area is located 70 km from the Fukushima Daiichi Nuclear Power Plant (NPP), which released a large amount of radioactive material into the environment following the Great East Japan Earthquake of 2011. For comparison, we examined monkeys inhabiting the Shimokita Peninsula in Aomori Prefecture, located approximately 400 km from the NPP. Total muscle cesium concentration in Fukushima monkeys was in the range of 78-1778 Bq/kg, whereas the level of cesium was below the detection limit in all Shimokita monkeys. Compared with Shimokita monkeys, Fukushima monkeys had significantly low white and red blood cell counts, hemoglobin, and hematocrit, and the white blood cell count in immature monkeys showed a significant negative correlation with muscle cesium concentration. These results suggest that the exposure to some form of radioactive material contributed to hematological changes in Fukushima monkeys.

© Inter-Research 2014. The Kuril harbour seal Phoca vitulina stejnegeri is an endangered species which in - habits southeastern Hokkaido, Japan. Its population declined precipitously from between 1500 and 4800 individuals in the 1940s to a few hundred individuals in the early 1970s. The causes of this decline are thought to be commercial harvesting, bycatch in autumn set-net salmon fishing, and other human activities, including coastal fisheries. To quantify Kuril seal population trends, counts were performed each year at haul-out sites during the pupping season from 1974 to 2010 and during the moulting season from 1983 to 2010. The average population growth rate was ∼4% per annum over the past 37 yr. Two haul-out sites (Kenbokki Island and Hattaushi) from which the species had disappeared in the early 1980s showed no evidence of being recolonized. Commercial harvesting ended in the late 1980s and probably had an effect on population trends until the 1990s. The bycatch of seals during autumn set-net salmon fishing in the 2000s remained similar to, or slightly greater than, that during the 1980s. Recently, seals have been observed at 9 haul-out sites during the pupping/moulting season along the coast of southeastern Hokkaido. Approximately 70% of the seals found were at Cape Erimo (∼500 seals) and at Daikoku Island and Akkeshi (∼250 seals).

© 2014 by the Society for Reproduction and Development. Feral raccoons (Procyon lotor) have been growing in number in Japan, and they are becoming a problematic invasive species. Consequently, they are commonly captured and killed in pest control programs. For effective population control of feral raccoons, it is necessary to understand their reproductive physiology and ecology. Although the reproductive traits of female raccoons are well known, those of the males are not well understood because specialized knowledge and facilities are required to study them. In this study, we first used a simple evaluation method to assess spermatogenesis and presence of spermatozoa in the tail of the epididymis of feral male raccoons by histologically examining the testis and epididymis. We then evaluated the possibility of using 7 variables—body weight, body length, body mass index, testicular weight, epididymal weight, testicular size and gonadosomatic index (GSI)—to estimate spermatogenesis and presence of spermatozoa in the tail of the epididymis. GSI and body weight were chosen as criteria for spermatogenesis, and GSI was chosen as the criterion for presence of spermatozoa in the tail of the epididymis. Because GSI is calculated from body weight and testicular weight, this model should be able to be used to estimate the reproductive state of male raccoons regardless of season and age when just these two parameters are known. In this study, GSI was demonstrated to be an index of reproductive state in male raccoons. To our knowledge, this is the first report of such a use for GSI in a member of the Carnivora.

Following the massive earthquake that struck eastern Japan on March 11, 2011, a nuclear reactor core meltdown occurred at the Fukushima Daiichi Nuclear Power Plant, operated by Tokyo Electric Power Company, and was followed by the release of large amounts of radioactive materials. The objective of this study was to measure the concentration of radiocesium 134Cs and 137Cs in the muscle of Japanese monkeys (Macaca fuscata) inhabiting the forest area of Fukushima City and to determine the change in concentration over time as well as the relationship with the level of soil contamination. Cesium concentrations in the muscle of monkeys captured at locations with 100,000-300,000 Bq/m2 were 6,000-25,000 Bq/kg in April 2011 and decreased over 3 months to around 1,000 Bq/kg. However, the concentration increased again to 2,000-3,000 Bq/kg in some animals during and after December 2011 before returning to 1,000 Bq/kg in April 2012, after which it remained relatively constant. This pattern of change in muscle radiocesium concentration was similar to that of the change in radiocesium concentration in atmospheric fallout. Moreover, the monkeys feed on winter buds and the cambium layer of tree bark potentially containing higher concentrations of radiocesium than that in the diet during the rest of the year. The muscle radiocesium concentration in the monkeys related significantly with the level of soil contamination at the capture locations. © 2013 Hayama et al.

© 2013 by Nova Science Publishers, Inc. All rights reserved. The cadmium (Cd) content in the kidneys and livers of wild birds was compared after classification based on the type of migration and the breeding area. A high Cd content was detected in the organs of Pacific loons breeding in North America, but these birds were thought to have been affected by oil contamination. The Cd content of organs from spotbill ducks, which are birds that are resident in Japan, tended to be higher than those of other birds that breed outside Japan. The rank order of the mean Cd level with respect to location was "only in Eurasia" < "both Eurasia and North America" < "only in North America". The type of migration did not affect the Cd content of the organs. We also investigated the relationship between the Cd content of the organs and the Japanese environmental concentration of Cd. The Cd contents of organs from birds collected on the shore of the Japan Sea were generally higher than those of the birds collected near the Pacific Ocean. These results seem to be related to the concentration of Cd in the soil. From these results, we showed that the differences in the Cd content in organs from Japanese wild birds were related to their breeding area but not to the type of migration. Further, the area from which the wild birds were collected was strongly related to the Cd content of the organs. This demonstrated the relationship between the environmental and soil conditions in Japan and the level of pollution of the birds studied.

Due to the long parturition period of raccoons, we assumed that age at first conception of late born females was later than that of early born females. From March 2005 to September 2008, 201 females estimated to be younger than 24 months were separated into early-and late-born groups on the basis of their estimated birth month (to the nearest 2 months), and parous status and body mass index (BMI) were examined. Age at first conception of late-born females (over 18 months old) was estimated to be later than that of early-born females (over 12 months old). The average BMI in early-born individuals at 12 months old might have affected their ability to conceive because of body fat deposition. © 2012 The Japanese Society of Veterinary Science.

We examined the use of external measurements and relative fat deposition of adult feral raccoons (Procyon lotor) to develop relative indices of body fat deposition in post-growth feral raccoons. From March 2006 to March 2010, 288 adult raccoon carcasses (110 males, 178 females) collected in Kanagawa Prefecture, Japan, which were determined to be 24 months old, were subjected to external measurements of body weight (BW), girth measurement (GM), and body mass index (BMI). To assess relative body fat deposition, we visually classified abdominal subcutaneous fat into three grades (Visible Fat Index [VFI]: I-III). Significant differences in the means of BW (both sexes:P<0.01), GM (females: P<0.05, males: P<0.01), and BMI (both sexes: P<0.01) were detected between seasons. Notably, the means of BW, GM, and BMI (all, both sexes: P<0.01) differed significantly between VFI grades. However, by discriminant analysis with BW, GM, and BMI as independent variables, we obtained a significant discriminant function (both sexes: P<0.01) for distinguishing VFI I from higher VFI grades, but no significant equation was obtained for distinguishing between VFI II and VFI III. Based on the obtained structure matrix of discriminant analysis, BMI was the most valuable component for the discrimination of VFI grades. Thus, we conclude that BMI is a suitable complementary index for assessing relative body fat deposition of adult feral raccoons in Kanagawa Prefecture and may be generalizable to populations in other areas.<br>

To estimate the public and animal health risk that alien species pose, the prevalence of Salmonella, Yersinia, and Campylobacter spp. in feral raccoons (Procyon lotor, n=459) and masked palm civets (Paguma larvata, n=153), which are abundant alien species in Japan, was investigated in urban and suburban areas of Japan. Salmonella enterica was detected from 29 samples [26 raccoons, 5.7%, 95% confidence interval (CI) 7.8-3.5%; three masked palm civets, 2.0%, 95% CI 4.2-0%]. Many of the isolates belonged to serovars that are commonly isolated from human gastroenteritis patients (e.g. S. Infantis, S. Typhimurium, and S. Thompson). The antimicrobial susceptibility test showed that 26.9 % of the isolates from raccoons were resistant to at least one antimicrobial agent, whereas none of the isolates from masked palm civets were resistant. Yersinia sp. was detected from 193 samples (177 raccoons, 38.6%, 95% CI 43.0-34.1%; 16 masked palm civets, 10.5%, 95% CI 15.3-5.6%). All virulent Yersinia strains belonged to Yersinia pseudotuberculosis, which was isolated from seven (1.5%, 95% CI 2.6-0.4%) raccoons and six (3.9%, 95% CI 7.0-0.8%) masked palm civets. According to the detection of virulence factors, all the Y. pseudotuberculosis isolates belonged to the Far Eastern systemic pathogenicity type. Campylobacter spp. was detected from 17 samples (six raccoons, 1.3%, 95% CI 2.3-0.3%; 11 masked palm civets, 7.2%, 95% CI 11.3-3.1%). Among these, three isolates from raccoons were identified as C. jejuni. These results showed that these pathogens can be transmitted by human activities, other wild animals, and the environment to feral raccoons and masked palm civets, and vice versa. As these animals have omnivorous behaviour and a wide range of habitats, they can play an important role in the transmission of the enteric pathogens. © 2011 Blackwell Verlag GmbH.

本研究では，野生カワウの飼育個体6頭を使用して，安静時における酸素消費量を計測し，季節による代謝率の変化を検討した。カワウにおける酸素消費量は，春，夏および冬に計測を行った。実験は恒温恒湿室内で行い，環境温度は全ての季節で25&deg;Cに設定した。酸素消費量は，馴化後に安静な状態で1時間計測した。各季節における実験実施日の個体の平均体重に有意な差は認められなかった(ANOVA，P＝0.483)。各季節における酸素消費量の平均値は，春が14.96 ml/min&middot;kg,夏が10.50 ml/min&middot;kg,冬が16.93 ml/min&middot;kgであった。それぞれの季節における平均値間に有意な差が認められ，日本産カワウにおける酸素消費量は夏に比べ冬が約1.6倍高くなることが明らかとなった。

Reproduction of the masked palm civet (Paguma larvata) has not been well investigated in Japan. We examined 361 female masked palm civets harvested as nuisance animals between April 2007 and March 2009 in Kanagawa Prefecture and Tokyo Metropolis. Pregnant animals and placental scars-bearing animals were found only in 12 months old and over. In these animals, the observed rate of pregnant animals was 13.7% (29/212) and that of placental scar-bearing animals was 29.2% (62/212). The number of fetuses ranged from 1-4 (average 2.8), and the principal months of parturition estimated from the crown-rump lengths of fetuses were from March to November.

【目的】ヒトにおけるShort tandem repeat（STR）多型は、親子鑑定・個体識別・人類遺伝学的解析など幅広く利用されている。さらに近年、性染色体特異的なSTRであるX‐STR、Y‐STRが開発され法科学的解析に重要な手法となっている。一方、動物においても、STR多型は個体識別・血統登録・品種分化などの手段として研究されているが、性染色体STRマーカーの開発はごく一部の種に留まっている。ニホンザルにおけるY-STR多型の開発は、ニホンザルの父系解析を可能とし、新たな集団遺伝学的知見が期待されることから、今回&nbsp;ニホンザルにおけるY染色体特異的STR座位の同定を試みたので報告する。<br>【材料および方法】日本獣医生命科学大学野生動物教育研究機構と福島市および新福島農業協同組合の研究協力協定に基づき得られたニホンザル標本より抽出したゲノムDNAを試料とした。Y-STR座位の同定は、82種類のヒトDYS座位を基にあらかじめPCR法を実施し、ニホンザル雄特異的な候補座位と判定した12遺伝子座について、1）塩基配列の解析、2）ニホンザル雄ゲノム特異的STRマーカーの再構築、3）雄20例を用いた多型性解析により実施した。<br>【結果および考察】これまでに解析した82種類のヒトDYS座位のうち、ニホンザルにおいて雄特異的バンドが増幅された5座位および雌雄で増幅バンドの移動度が異なる7座位の計12座位についてダイレクトシークエンス法により塩基配列を決定した結果、10座位で、(TC)(TATC)、GTT、TAGAなどの雄特異的STR配列が認められた。そこで、雄特異的STR遺伝子座（Y-STR）10座位の塩基配列をリファレンスとした。リファレンス配列では、STR配列を含む領域（199bpから380bp）においてヒトゲノム配列との相同性は65％から87％と座位間で差が認められた。さらに、ニホンザルの雄ゲノムに特異的でかつヒトゲノムでバンドが増幅しない、ニホンザルY-STRマーカーの設計を試みた結果、10種類のうち7種類の座位でニホンザルY-STRの作成が可能であった。なお、20個体（福島県ニホンザル）を最初のスクリーニングパネルとし開発した10種のニホンザルY-STRマーカーで多型性の有無について解析を進めており、現在少なくとも5座位（最大対立遺伝子数、5）で多型性を見出している。以上、今回ニホンザルにおけるY染色体特異的STR座位の同定は、父系マーカーを利用した新たなニホンザル集団の遺伝子構成の解明に繋がるものと考える。

ニホンツキノワグマUrsus thibetanus japonicus(以下,クマ)の人の生活圏への出没には、いくつかの要因が考えられているが、その一つに里地里山(以下,里地)環境の荒廃が挙げられている。本研究は、クマの出没と里地環境との関係を解析し、クマの出没要因の解明を目的とした。本研究は、群馬県沼田市にて、2008年10月から12月の期間に行った。クマの出没に関連すると考えられる里地環境を畑地、水田、果樹園、不作付け地、荒地、林縁と定義し、これらの位置、作付け状況、管理状況を調査した。解析には、地理情報システムによって定量化した里地環境のデータと調査地におけるクマの出没地点データを用いた。解析は、巨視的解析と微視的解析に分け、それぞれ、作成した区画、クマの出没地点を基にして行った。巨視的な解析では、クマの出没と地形の複雑性(P<0.01)および土地利用における果樹園の割合(P<0.01)との間に正の相関が確認された。微視的な解析では、クマの出没が、果樹園(P<0.01)および藪化レベルが高い林縁周辺(P<0.05)に偏っていることが確認された。解析の結果、クマの出没には、地形の複雑な場所であることと、果樹園と藪の存在が影響していると考えられた。

This study is the first to determine the conception dates of specific individuals and estimate the pregnancy rate of a wild population in Japanese monkeys. The conception dates estimated from the embryonic ages of 37 fetuses were distributed over 128 days between September 17 and January 23, with a mean conception date of November 19 (SD=29.2 days). A comparison of the mean conception dates among age groups showed a significantly delayed conception in the subadult animals (aged 4 to 5 years; December 5, n=8) than in the adult animals (aged 6 or more years; November 15, n=29; P<0.03). The mean pregnancy rate among animals aged 4 years or more in this local population was estimated to be 48.5% (32/66).<br>

野生のツシマヤマネコにおける栄養状態診断基準の確立を目的として，体脂肪蓄積指標の評価に関する研究を行った。体脂肪蓄積指標を検討するために, 1985年から2007年の間に調査目的で捕獲された個体および事故等で保護収容された個体のうち, 明らかに疾病等で衰弱し, 栄養不良と判断された個体を除く101頭の外部計測値を使用した。外部計測値は, 対馬野生生物保護センターで計測された体重(ｇ), 体長(mm), 後足長(mm)を使用した。また, ツシマヤマネコの死体24頭における肉眼的脂肪指数および背側皮下脂肪指数から相対的な体脂肪蓄積を評価し, 標本集団を体脂肪高蓄積群と体脂肪低蓄積群に分けた。この2群について、各標本の体重(BW), 体長(BL), 後足長(HFL), 肥満指数(BMI)を独立変数として判別分析を行った結果、以下に示す判別関数式が求められた(P=0.047)。この判別関数式の判別率は83.3%だった。Z＝0.001(BW)－ 0.014(BL)＋0.082(HFL)＋0.006(BMI)－4.304この判別式を用いることで、ツシマヤマネコの生体における体脂肪蓄積量を簡便に評価できることが明らかとなった。

2006年～2007年に，神奈川県逗子市および葉山町で捕獲されたアライグマProcyon lotorから直腸便と消化管内容を採取し，消化管内寄生蠕虫相を調査した。検出された寄生蠕虫種は合計8種で，その内訳は，不明線虫が2種，棘口吸虫科の吸虫類が2種，鉤頭虫類がSouthwellina hispida，Porrorchis oti，Sphaerirostris lanceoides，不明鉤頭虫の4種であった。調査地域のアライグマの寄生虫相は比較的単純であり，アライグマの原産地（北アメリカ）で認められる寄生虫種は確認されなかった。

Changes in body mass of a pair of captive Japanese Rock Ptarmigan Lagopus mutus japonicus and their chicks were measured using an automatic weighing system at Omachi Alpine Museum from 13 January 1995 to 29 October 1996. The male's body mass decreased gradually in late April, the beginning of the breeding season, but returned to the normal level in the fall. In contrast, the female's body mass increased rapidly from late April onward, peaking in late May, just before the egg-laying period. Thereafter, the female's body mass decreased throughout the egg-laying, incubation, and early brooding periods, but began to increase again in the fall. In 1996, four chicks were successfully reared and their body mass increased linearly during the first 60 days after hatching, followed by a milder increase.

© 2010 by Nova Science Publishers, Inc. All rights reserved. The cadmium (Cd) content in the kidneys and livers of wild birds was compared after classification based on the type of migration and the breeding area. A high Cd content was detected in the organs of Pacific loons breeding in North America, but these birds were thought to have been affected by oil contamination. The Cd content of organs from spotbill ducks, which are birds that are resident in Japan, tended to be higher than those of other birds that breed outside Japan. The rank order of the mean Cd level with respect to location was "only in Eurasia" < "both Eurasia and North America" < "only in North America". The type of migration did not affect the Cd content of the organs. We also investigated the relationship between the Cd content of the organs and the Japanese environmental concentration of Cd. The Cd contents of organs from birds collected on the shore of the Japan Sea were generally higher than those of the birds collected near the Pacific Ocean. These results seem to be related to the concentration of Cd in the soil. From these results, we showed that the differences in the Cd content in organs from Japanese wild birds were related to their breeding area but not to the type of migration. Further, the area from which the wild birds were collected was strongly related to the Cd content of the organs. This demonstrated the relationship between the environmental and soil conditions in Japan and the level of pollution of the birds studied.

In this study, based on the data from FIV screening surveys of captive cats conducted by the Kyushu Veterinary Union and collaborators as part of the infection control program for Tsushima leopard cats (Prionailurus bengalensis euptilurus), we elucidated the spatial distribution of FIV-positive individuals among leopard cats and domestic cats using a geographic information system. Data from FIV screening surveys carried out among 86 leopard cats (1996-2006) and 713 captive domestic cats (2001-2006) were used for analysis. The analysis results were then spatially layered with the population density of leopard cats and that of captive domestic cats estimated from the number of households and used for assessment of FIV infection risk in each area. The prevalence rates of FIV were 3% (3/86) in leopard cats in Kami-shima, 13.6% (38/280) in domestic cats in Kami-shima and 10.6% (46/433) in domestic cats in Shimo-shima. The distribution of FIV on Tsushima Island was not uniform; on Kami-shima Island, FIV-positive domestic cats were concentrated in particular areas. We also performed risk analysis based on the population density of leopard cats, the prevalence rate of FIV among domestic cats in each area and the estimated population density of captive domestic cats and identified high FIV infection risk areas. All FIV-positive leopard cats were found in the identified high FIV infection risk areas.<br>

A symbiotic bacterium of the macaque louse, Pedicinus obtusus, was characterized. The symbiont constituted a gammaproteobacterial lineage distinct from the symbionts of anthropoid primate lice, localized in the midgut epithelium and the ovaries and exhibiting AT-biased genes and accelerated molecular evolution. The designation "Candidatus Puchtella pedicinophila" was proposed for it. Copyright © 2009, American Society for Microbiology. All Rights Reserved.

The characteristics of autonomic nervous activity were examined on captive great cormorants Phalacrocorax carbo hanedae, using a power spectral analysis of heart rate variability. Heart rates were calculated from recordings of the electrocardiograms of the birds via embarked data loggers. We investigated the effects of blockades of the sympathetic or parasympathetic nervous systems using the indices of autonomic nervous activity such as high frequency (0.061-1.5 Hz) component, low frequency (0.02-0.060 Hz) component and the low frequency power component to high frequency power component ratio. Resting heart rate (85.5 ± 6.1 bpm) was lower than the intrinsic heart rate (259.2 ± 15.3 bpm). The heart rate drastically increased after the injection of the parasympathetic nervous blocker, on the other hand it slightly decreased after the injection of the sympathetic nervous blocker. The sympathetic, parasympathetic and net autonomic nervous tones calculated from heart rate with and without blockades were 40.9 ± 27.6, -44.5 ± 7.4 and -29.5 ± 9.0%, respectively. The effect of the parasympathetic nervous blockade on low frequency and high frequency power was greater than that of the sympathetic nervous blockade. Those data suggested that the parasympathetic nervous activity was dominant for great cormorants. © 2009 Springer-Verlag.

種の保存とランドスケープ－21世紀における自然と人との共生のあり方を考える。絶滅危惧種の回復と行動計画の意義。2008年版のレッドリストでは、16,928種もの絶滅危惧種が掲載されており、このような状況がさらに続けば、生物の多様性は大きく損なわれ、人類の生存基盤でもある生態系を健全に維持できなくなることは論を待たない。そのため、絶滅危惧種の回復は科学的にも政策的にも喫緊の課題といえる。また、絶滅危惧種を回復させるためのさまざまな取り組みは、結果的に地域の自然の再生や地域社会の発展に効果が期待される。このような事例は、わが国でもニホンコウノトリの野生復帰の例などをはじめとして明らかとなってきた。各地の自然再生事業を発展させるためには、むしろ絶滅危惧種を回復させるための行動計画を事業化することが効果的であり、また生物多様性を保全する観点から優先されるべきであると考える。

In order to examine reproductive characteristics of feral raccoons in Kamakura, 335 raccoons were collected from March 2005 to March 2007. Raccoons were classified into five age classes: Class I, less than 5 months old; Class II, 5-11 months; Class III, 12-17 months; Class IV, 18-23 months; and Class V, over 23 months old. Females were examined for their age specific pregnancy rate and litter size. To determine when raccoon births occur in the region, birth months of fetuses were estimated by the fetal growth rate, and birth months of Class I individuals were examined by tooth eruption. From fetuses of 18 pregnant females and 47 Class I individuals, it was found that the raccoon births occur from February to October. Of 163 females examined, all of Class I-II females were nulliparous. Pregnancy rate was 47.6% in Class III females, which was significantly lower than 75.0% in Class IV and 78.1% in Class V. The litter size of fetuses ranged from 2 to 5, and 3.9 on average; and that of placental scars ranged from 1 to 7, 3.8 on average. Our findings suggest that parturition of raccoons is a bimodal distribution and age at first parturition may occur between 12 and 17 months old. In order to reduce the raccoon population successfully, females of all ages should be captured throughout the year.<br>

ダイオキシン類は,実験動物あるいは野生生物が暴露した場合,甲状腺の機能や形態に影響を及ぼす。今回我々は野生ニホンザル(Macaca fuscata)の甲状腺におけるダイオキシン類の影響について報告する。野生サルはヒトの居住地の周辺で生活しており,生物分類学的にヒトに最も近い動物種である。野生サルの脂肪組織,肝臓,骨格筋からダイオキシン類(PCDDs,PCDFs,Co-PCBs)の残留濃度を分析した。また,甲状腺については病理組織学的に検索し,画像解析を用いて濾胞上皮細胞の肥大を定量的に評価した。PCDDs,PCDFs,Co-PCBsの残留濃度はいずれも0.2〜26pgTEQ/g-fatの範囲だった。病理組織学的検索において,TEQに関連した甲状腺の変化は認められなかった。さらに,濾胞の数や濾胞上皮細胞の大きさにもTEQに関連した変化は認められなかった。このように,野生ニホンザルは自然環境からダイオキシン類に暴露されてはいたが,検出されたレベルでは甲状腺の機能や形態に影響を及ぼさなかったと考えられた。

1955年頃から, 森林の崩壊地の復旧や道路脇の緑化として, 牧草を用いた緑化工は全国的に拡がった.牧草を用いた草地が, ニホンジカ(Cervus nippon)の食性に与える影響を調べるため, 本研究では, 塔ノ岳の緑化工による草地の周辺に生息する人馴れしたメスジカ「個体D」を詳細に観察し, 調査地周辺の主要な3種類の下層植生の現存量調査を行った.冬期, 個体Dは採食時間の77%から84%でササを採食していた.夏期には, 個体Dの主要な餌植物は緑化工の植物で, 採食時間の45%から75%を費やしていた.ミヤマクマザサ(Sasa hayatae Makino)とヒメノガリヤス(Calamagrostis hakonensis Franch. et Sav.)の2種の野生草本の現存量は10月に減少し始めた.一方, シカの継続的な高利用にもかかわらず, 緑化草地の現存量は11月まで増加し続けた.個体Dの行動圏は著しく小さく(夏の1.6haから秋の4.0ha), コアエリアの位置は食性の影響を受けていた.個体Dの移動はササや緑化草地といった単一の植生に依存していた季節に減少していた.牧草を用いた緑化工は個体Dに高質で継続的に利用可能な餌場を提供し, 行動圏の大きさや移動様式にも影響を与えていたことが示唆された.ニホンジカの分布域において, 緑化工はシカの栄養状態を向上させる可能性がある.そのため, 生息地本来の環境収容力以上に密度を増加させるかもしれない.シカの生息地管理には, 緑化工の規模や配置を考慮に入れる必要がある.

We compared morphologic changes in thyroid glands of great cormorants (Phalacrocorax carbo) from the Tokyo Bay and Lake Biwa areas in Japan with presence of residues of polychlorinated dibenzo-dioxins (PCDDs), polychlorinated dibenzo-furans (PCDFs), and coplanar polychlorinated biphenyls (Co-PCBs). Prominent morphologic changes in thyroid glands included increased density of small follicles and increased number of epithelial cells surrounding follicular lumens. The extent of morphologic changes in the thyroid gland was higher in cormorants captured from Tokyo Bay than in those captured from Lake Biwa. Increased thyroid change in cormorants from the Tokyo Bay area was associated with significantly higher levels of PCDFs and Co-PCBs. Thus, we suggest that morphologic changes in thyroid glands from the cormorants are associated with increased levels of dioxin contamination in Japan. © Wildlife Disease Association 2004.

To conduct preliminary studies of food conditions for sika deer Cervus nippon in the eastern part of the Tanzawa Mountains, we analysed crude protein (CP), fiber, calories, and in vitro digestible dry matter (DDM) using the rumen fluid of sheep on evergreen broadleaf tree species, deciduous tree species, grass and forbs. Significant positive correlations were found between CP content and neutral detergent solubles {100 - (neutral detergent fiber)} (r = 0.38, n = 114), among fiber contents (r = 0.52 to 0.78, n = 92), between calorie and fiber content (r = 0.36 to 0.48, n = 92) and between CP and DDM (r = 0.49, n = 84). Significant negative correlations were shown between CP and calories (r = -0.42, n = 114), CP and fibers (r = -0.32 to -0.41, n = 114), between DDM and calories (r = -0.31, n = 84), and between DDM and fibers (r = -0.46 to 0.77, n = 84). A predictive equation (r² > 0.82, p < 0.001) for dry matter digestibility from CP, silica, and fiber composition was developed. We then discussed the nutritional values of several food items for free ranging sika deer and their connection with habitat use.

バンドウイルカ(成獣雄2頭,成獣雌2頭,幼獣5頭)の血液性状(一般検査3項目,生化学検査19項目)の季節変動を群単位で比較検討した.合計504検体の血清クレアチニン濃度に3群で有意な季節変化がみられ,夏の平均値は冬よりも15-38%高かった.3群中2群で,総コレステロールの平均値は冬で最高値を示し,夏で最低となった.遊離脂肪酸平均値は2群で,夏が高く冬が低かった.

化学物質による野生鳥類の研究史についてわが国の取り組みを紹介した.ダイオキシン類の汚染が大きな注目を浴びた近年,それらの問題に向けた対策や技術は大きな社会現象にもなった.わが国における化学物質による野生動物への影響に関する研究は,未だ少ないのが現状である.著者らは,魚食性鳥類であるカワウに着目し,ダイオキシン類の体内残留レベルを明らかにすると共に,既報の日本産鳥類のデータと比較した.その結果,カワウは最も高濃度に蓄積する鳥種であった.またPCDD/Fs の残留パターンは, 2,3,7,8-置換体PCDD/Fsが優占し,WHO-TEF (birds) を用いた毒性値への寄与には,1,2,3,7,8-PeCDDや2,3,4,7,8-PeCDF,CB126が大きな寄与を示した.肝臓におけるこれらのコンジェナーは,筋肉や卵よりも特異に蓄積していた.<br>カワウにおけるダイオキシン類の半減期を算出し,環境濃度から卵への濃度を予測した結果,孵化率への影響は1970 年代をピークに減少傾向であることが推察された.現在のダイオキシン類の曝露による未孵化率は27%と見積もられ,個体群の減少には影響しないことが結論づけられた.しかしながら,別のエンドポイントや免疫などの調査の必要性が考えられ,これらを遂行するための非捕殺的モニタリング手法など,カワウ個体群をリスク管理するための新たな取り組みが期待された.

The Great Cormorants (Phalacrocorax carbo) have recently gave impacts on forestry and fishery in Japan. To decrease the population of this species, culling was operated in many locations, which appeared not to be so effective. These human-cormorant conflicts have not been mitigate easily because so many factors are contributed. The special animal management planning system will be applied in the future under the Wildlife Protection and Hunting Law.

Concentrations of 2,3,7,8-substituted polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and non- and mono-ortho-chlorine-substituted polychlorinated biphenyls (dioxin-like PCBs) were measured in livers of 17 species of birds collected from Japan. Birds were grouped according to their feeding habits as granivores, piscivores, omnivores, and predators for discussions. Livers of granivores contained relatively low concentrations of PCDD/DFs (80-660 pg/g) followed in increasing order by omnivores (2,300- 8,000 pg/g), piscivores (61-12,000 pg/g) and predators (480-490,000 pg/g on a fat weight basis). Especially, one species of predatory bird (mountain hawk eagle) contained elevated concentrations of PCDDs, PCDFs, and dioxin-like PCBs, and the measured concentration is one of the highest reported to date. Homolog and congener patterns of PCDDs and PCDFs varied among species; hence, the results suggested that feeding habits, specific elimination, and metabolism influence contamination pattern. Concentrations of dioxin-like PCBs were in the order of granivores (32- 83 ng/g) < predators [excluding mountain hawk eagle] (32-2,500 ng/g) < piscivore (61-12,000 ng/g) < omnivores (1,800-67,000 ng/g on a fat weight basis). Mountain hawk eagle contained the highest concentration of dioxin-like PCBs (55,000 ng/g fat weight). 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) toxic equivalents (TEQs) ranged from 53-450,000 pg/g fat weight. 23478-PeCDF, 2378-TCDD/TCDF, and PCB congeners IUPAC 126 and 77 were major contributors to TEQs in birds. To our knowledge, this is the first study of PCDD/DFs and dioxin-like PCBs in livers of several species of Japanese birds.

When rearing chicks, Leach's storm-petrels (Oceanodroma leucorhoa) commute between foraging areas and breeding colonies with heavy food loads. At this time they should maximize the size of energy-supplying organs in response to increased energy expenditure but minimize total body mass to decrease the energetic cost of flight. Nineteen storm-petrels were killed to examine the changes in body composition and the masses of energy-supplying organs in birds that were incubating and rearing chicks. Parents lost a mean of 7.95 g in body mass between the stages of incubation and chick-rearing mainly via a loss of skin including subcutaneous adipose tissue, and a small fraction of heart and digestive organs, which are considered energy-supplying organs. This mass loss actually enables them to decrease flight cost by 14.4%. The benefits of decreasing flight costs by reducing total body mass are greater than if the energy-supplying organs of birds are enlarged only.

Concentrations and patterns of several chlorinated persistent organic pollutants (POPs) including polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs) and biphenyls (PCBs) and DDTs, HCHs, CHLs and HCB were determined in black-tailed gulls (Larus crassirostris) from breeding grounds in Hokkaido, Japan. Subcutaneous fat of five adult gulls was analyzed, which had different concentrations of target compounds, whereas gull eggs contained similar concentrations of target compounds. Similar congener profiles were found between adult gulls and eggs. The concentrations of non-ortho PCBs varied from 3.4 to 13.5 ng/g lipid weight (lw) in the fat of black-tailed gulls and from 2.4 to 7.4 ng/g lw in their eggs. 2,3,7,8-PCDD/Fs occurred at relatively lower concentrations than non-ortho PCB congeners in both adult gulls and eggs. The total TEQs (toxic equivalents, PCDD/Fs+ non-ortho PCB) ranged from 0.26 to 1.0 ng/g lw in adult gulls and ranged from 0.19 to 0.58 ng/g lw in eggs. © 2001 Elsevier Science Ltd. All rights reserved.

東京湾周辺に生息するカワウ肝臓 (n=16) 中ダイオキシン類 (PCDD/Fs, Co-PCBs) を分析した。PCDD/Fs濃度は平均33, 000pg/gfatであった。すべての試料で2, 3, 7, 8一置換体が約90%を占め, 特に1, 2, 3, 7, 8-PeCDDと2, 3, 4, 7, 8-PeCDFが優占的にみられた。生物蓄積係数 (BMF) は, 2, 3, 7, 8-TCDF (0.82～1.4) から2, 3, 4, 7, 8-PeCDF (130～380) まで魚種や異性体によって大きな差がみられ, またCo-PCBsにおいてもCB77 (5.6～32) からCB169 (320～1900) まで幅広いBMFの値がみられた。これらの蓄積性はLog Kowや分子量, 構造のいずれの比較でも説明できず, 生物特有の代謝が考えられた。WHO-BirdsTEFを用いて求めた総TEQは, 27, 000pgTEQ/g fatであり, その半分をPCDD/Fsの1, 2, 3, 7, S-PeCDD (13%) と2, 3, 4, 7, 8-PeCDF (36%) , Co-PCBsのCB126 (28%) が大きく寄与していた。オランダ産カワウの報告例と比較すると1, 2, 3, 7, 8-PeCDDが高濃度であった。