ボノボはコンゴ川とに挟まれたコンゴ盆地の熱帯林に生息しているが、コンゴ盆地内での広域的な遺伝子構造は明らかになっていない。本研究では、多様な遺伝標識を利用し、野生ボノボの集団構造と地域個体群の孤立評価に関する基礎データを収集することを目的とした。ボノボでは、地域間の遺伝子交流に対するメスの寄与が大きいと考えられる。今回、野生個体群のミトコンドリアDNA（mtDNA）変異の多様性や地理的分布を詳しく調査した結果を報告する。
　ボノボ生息地の7地域で調査をおこない、直接観察やネスト下から新鮮な糞試料を採取した。約150検体につき、mtDNA非コード領域の全塩基配列（約1,130bp）を解読し、クラスター分析で主要なハプログループを特定した。各試料の採集地点情報をもとにハプログループの地理的分布の特徴を検討した。
　輸出個体の分析から、従来の研究ではボノボのmtDNAには３つの主要なハプログループ（Ａ, Ｂ, C）が報告されていた。しかし、これらの自然分布に関する情報はほぼ皆無であった。今回の調査では、既知の３グループに加えて第４のハプログループ（暫定的にXと呼ぶ）を発見した。ハプログループ分類から比較すると、mtDNAタイプの種類と頻度は調査地による違いが顕著だった。Ａグループタイプは広域に分布するものの西端と東端の調査地では確認できなかった。ＢグループタイプはWambaを除く全ての調査地に分布していた。ＣグループタイプはWamba周辺に局在していた。さらに、Xグループタイプは東端に局在していた。
　今回観察された結果は、河川などの地理的障壁やその地史的変遷に深く影響されている可能性がある。今後さらに検討を加えていく。

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第15回国際カイアシ類学会を終えて

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「親指ピアノ」は, アフリカで生まれ, 現在でもサハラ以南のアフリカ各地に広くみられる楽器である。本稿では, アンゴラ北東部に暮らすチョクウェの音文化のなかで「親指ピアノ」に焦点をおいて, その楽器の形態やそこから演奏される曲の歌詞を分析することから, チョクウェの音文化と生活とのかかわりあいを把握する。調査は, アンゴラ北東部のドュンド町内や近郊に住む9人の演奏者を対象にして, 聞き取り調査や演奏曲を録音する作業をおこなった。
チョクウェは, アンゴラ東部を中心にして居住するバンツー系の人々である。彼らは, キャッサバ栽培などの農耕を中心として, 狩猟, 漁労, 出稼ぎなどを複合させた生業を営んでいる。まずこの地域では, 各々の形態の違いに応じて独自の名称を持つ8種類の「親指ピアノ」を確認できた。また, 収集された43曲は, 男性によって単独で演奏されるのもので, すべての曲に歌詞がついていた。このうち31曲の歌詞の内容を分析すると, 経済生活, 男女関係や親子関係, 日常生活, 出来事, 割礼儀礼, 植民地時代の歴史などに分類される。さらに, 1960年代の報告と現在のものとを比較すると,「親指ピアノ」は, 娯楽としては使われている点では共通しているものの儀礼の際には用いられなくなっていた。本稿ではこの楽器の機能として, 歌詞のなかに登場していた様々な出来事が次の世代に伝承されていくことから, 当時の生活世界が反映された個人史が伝承される点に注目している。

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This paper discusses the processes of woodland environment formation in Western and Northwestern Zambia in a part of the eastern marginal zone of the Kalahari Sands which spread over the inland Central and Southern Africa.
Present-day climatic condition of the area is considered adequate for the existence of dry evergreen forests contrary to actually dominant open deciduous woodlands. Small patches of dry evergreen forest are scattered in woodland on the plateau composed of the Kalahari Sands with very porous and oligotrophic Arenosols. On the other hand the adjacent bedrock plateau which have a little more nutritious Ferralsols is covered extensively by mosaic of deciduous woodland and cultivated land. Vegetation-ecological survey has demonstrated that existing small dry evergreen forest patches show very stable community structure maintained by natural renewal in contrast with repeatedly intervened structure of woodland communities. Palaeoenvironmental analysis based on surface-geological, geomorphological, and pedological evidences has concluded the prevalence of dryer climate in Latest Pleistocene time around 20, 000y. B. P., when the uppermost member of the Upper Kalahari Sands were redeposited on the plateau, and the following climatic humidification around the Pleistocene-Holocene boundary about 10, 000y. B. P., when the lower terrace was formed along the Kabompo River. Radiocarbon dating of the charcoal-rich layers which, intercalated in surface sands under woodland, indicate the occurrence of extensive burning provides about 2, 500y. B. P. and 1, 000y. B. P. An evidence of accelerated erosion due to deforestation since 400y. B. P. has been given in the Nyika Plateau, a famous former iron-smelting zone on the Zambia-Malawi border. All the material as above is concordant with previously-known palynological and archaeological records and supports a hypothesis as follows.
Dry evergreen forest seems to have (re) appeared in the area in humified climate of around 10, 000y. B. P. and to have gradually replaced by deciduous woodland mainly through human activity during recent thousands of years, particularly several hundred years. Although slight climatic aridification in the time may have affected the vegetational change, arrival of Later Iron Age farmers and diffusion of a type of slush-and-burn cultivation such as citemene system have more greatly contributed to the recession of Zambezian dry evergreen forest and appearance and maintenance of some types of open deciduous woodlands. Cultivators' preference of Ferralsols rather than very porous and oligotrophic Arenosols has resulted in the uneven remaining of small patches of dry evergreen forest on the plateau composed of the Kalahari Sands, although the Kalahari Sands' water-retaining character in dry season may provide a little suitable condition for existence of forest.

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This study describes how the vocal repertoire of wild pygmy chimpanzees reflects their social relationships. The data were collected from the El and E2 groups at Wamba, in central Zaire.
The pygmy chimpanzee vocal repertoire in Wamba was divided into six categories based on the vocal sounds and social contexts. Note that this repertoire lacks vocalizations emitted during dyadic interactions. Directed vocalizations were emitted by a single individual, and others rarely responded.
The most important category in pygmy chimpanzee vocal repertoire is “Hooting” as contact call. However, the individual vocal variation was so small that it was hard to identify pygmy chimpanzees by their vocalizations only. They were also hard to identify by their vocalizations becauses all members of a party emitted loud Hooting simultaneously. Synchronization or turn-taking during vocal chorus was rare.
The contact calls of the pygmy chimpanzee of Wamba has two particular social features. (1) Many individuals can participate at the same time or the equivalent way using the same vocalizations. In these situations, neither dominant-subordinate relationships nor other relations between particular two individuals become evident. (2) Information involved in the communication can be obtained just by hearing the vocalization of others. Each participant may select two opposite behaviors according to these two features either (1) vocalizing with others or (2) listening to the vocalization of others. Pygmy chimpanzees seem to attach more importance to (1) than (2); they prefer joining vocalization to listening.
This characteristic of pygmy chimpanzee vocal communication may reflect a unique character of their society. The pygmy chimpanzee group seldom disperses into small parties, and moves in a large single party including almost all members of the group. From their social interactions, no particular affinitive relationship except between mother and offspring could be discerned. This pattern of pygmy chimpanzee vocal communication may indicate that their tendency to gather in a large party is not due to the network of affinitive dyadic social relationships, but to their preference to “gather” itself; each member of the group interacts equally with almost all members of a group.

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