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详细书目
| 文件类型: | 文章 |
|---|---|
| 所有的著者/提供者: | Richard N Renouf |
| ISSN: | 0022-541X |
| OCLC号码: | 479928939 |
| 语言注释: | English |
| 奖励: |
摘要:
Waterfowl utilization of 41 beaver ponds in south-central New Brunswick was studied during 1969. Ponds occupied by beaver (Castor canadensis), temporarily or during the entire field season, were defined as active. There were 15 active and 26 inactive ponds. Black ducks (Anas rubripes) comprised 27 of the 47 broods observed. In addition, green-winged teal (Anas carolinensis), hooded merganser (Lophodytes cucullatus), ring-necked duck (Aythya collaris), common goldeneye (Bucephala clangula), and mallard (Anas platyrhynchos) broods were seen. Thirty-eight broods were sighted on active ponds and only nine on inactive ponds. Active ponds contained 0.75 brood per acre and inactive ponds 0.11 brood per acre. The seasonal drop of the water level was less in active ponds than in inactive ponds. Hence, brood cover was more abundant in active ponds, and the active ponds were better brood-rearing areas.
