Fish Trap at Gastang weir in the River Wyre in August 1951

Fish trap at Garstang weir in the River Wyre, North West of England, UK. This photo shows pollution in River Lune in July 1949. This photo is part of a Photo Album that includes pictures from 1935 to 1954.

Churchtown Weir in the River Wyre

Churchtown Weir in the River Wyre, North West of England, UK. This photo is part of a Photo Album that includes pictures from 1935 to 1954.

Polygynous Mating System and Behavioural Reason of Black Crested Gibbon (Nomascus concolor jingdongensis) at Dazhaizi,Mt.Wuliang, Yunnan,China

2003年8月—2005年8月,对无量山大寨子5个黑长臂猿群体的结构和组成进行了观察。当一个群体在早晨鸣叫或依次通过树冠时,记录群体的结构和组成。每个群体都由1个成年雄性、2个成年雌性及其后代组成。2003年8月平均群体大小为6·2只;到2005年8月,平均群体大小发展为6·4只,其中有2个亚成年雄性从出生群迁出,且有3只幼猿出生。在3个群体(G1、G2和G3)中两个成年雌性都成功繁殖了后代。同一群体内两个成年雌性间无攻击或等级行为。2005年4月15日,当一只亚成年雌性进入G3的领域后,两只成年雌性对其进行追逐驱赶,并且干扰其与成年雄性配合进行二重唱,成年雄性没有直接驱赶流浪的亚成年雌性,10天后这只亚成年雌性离开了G3的领域。亚成年雄性经常与群体其他成员保持一定距离,并且在出生地通过独唱练习鸣叫。黑长臂猿可能通过亚成年雄性和雌性的迁出,及成年雌性对外来流浪雌性的驱赶维持这种一夫二妻的群体结构。

Coexistence of monogamy and polygyny in black-crested gibbon (Hylobates concolor)

All gibbons are monogamous and territorial with the exception of Hylobates concolor. This paper reports the coexistence of monogamy and polygyny in black-crested gibbons. Based on the fact of two adult females and two offspring of the same age category in one group and other reasons, we suppose that the two adult females have bred in a single group, i.e. a polygynous one. The other main reasons are: (1) a large home range makes it possible for more individuals to live in one group; (2) mutual tolerance among two females; and (3) selection pressure favouring polygyny.

Status and distribution pattern of black crested gibbon (Nomaseas concolor jingdongensis) in Wuliang Mountains, Yunnan, China: implication for conservation

The western black crested gibbon (Nomascus concolor), or black gibbon, one of the lesser apes (Hylobatidae), is mainly distributed in Yunnan, China. Of the four recognized subspecies, N. c. jingdongensis is endemic to the Wuliang Mountain, central Yunnan,

Can a group elicit duets from its neighbours? A field study on the black-crested gibbon (Nomascus concolor jingdongensis) in Central Yunnan, China

We tested the intergroup spacing hypothesis with a 13-month field study of the interaction of singing behaviour between 3 neighbouring groups of black-crested gibbons (Nomascus concolor jingdongensis) at Mt. Wuliang, Central Yunnan, China. Neighbouring gr

Effects of food and topography on ranging behavior of black crested gibbon (Nomascus concolor jingdongensis) in Wuliang mountain, Yunnan, China

We studied the ranging behavior of a habituated group of black crested gibbons (Nomascus concolor jingdongensis) in a high, seasonal habitat on Mt. Wuliang, central Yunnan, China, between March 2005 and April 2006. Our results indicated that the total home range size for the study group was 129 ha, or 151 ha if the lacunae within the borders in which gibbons were not observed were included. This is a much bigger range size than that of other gibbon species. However, 69.7% of their activities occurred within 29 ha. The intensity of quadrant use was significantly correlated with the distribution of important food patches. The mean yearly daily path length was 1,391 m. Gibbons traveled farther when they spent more time feeding on fruit. To avoid often passing through ridges with little food, gibbons usually stayed in the same valley for successive days, and then moved on to another valley for another several days, which resulted in a concentrated ranging pattern.