Consumption choice by bears feeding on salmon
Consumption choice by bears feeding on salmon
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DOI：
10.1007/s004420000590
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发表时间：
2001-05-01
期刊：
影响因子：
2.7
通讯作者：
Willson, MF
中科院分区：
文献类型：
--
作者：
Gende, SM;Quinn, TP;Willson, MF
棕熊和黑熊的消费选择。从1994年到1999年，在布里斯托湾（红鲑，Oncorhynchus nerka）和阿拉斯加东南部（粉红，O. gorbuscha和chum salmon O.凯塔）。这些数据揭示了部分和选择性消费的惊人模式，这些模式因鱼的相对可用性和属性而异。随着鲑鱼供应量的减少，熊在不同年份和栖息地中消耗了更大比例的每种鱼。当可获得性高时（鲑鱼的绝对数量和密度），熊每捕获一条鱼消耗的生物量较少，目标是能量丰富的鱼（那些没有产卵的鱼）或能量丰富的身体部位（雌性的卵;雄性的大脑）。相比之下，在鲑鱼供应量低的生境或年份，个体鱼类的消费量要大得多，无论性别或产卵状况如何。当产卵状态受到统计控制时，每条鱼消耗的生物量比例对于雄性和雌性是相似的，但熊针对不同的身体部位：雄性的身体肌肉、大脑和背驼峰，雌性的鱼卵。因此，熊似乎通过修改消耗的数量和身体部位，根据产卵鲑鱼的可用性和属性，最大限度地提高能量摄入。
Consumption choice by brown (Ursus arctos) and black bears (U. americanus) feeding on salmon was recorded for over 20,000 bear-killed fish from 1994 to 1999 in Bristol Bay (sockeye salmon, Oncorhynchus nerka) and southeastern Alaska (pink, O. gorbuscha and chum salmon O. keta). These data revealed striking patterns of partial and selective consumption that varied with relative availability and attributes of the fish. As the availability of salmon decreased, bears consumed a larger proportion of each fish among both years and habitats. When availability was high (absolute number and density of salmon), bears consumed less biomass per captured fish, targeting energy-rich fish (those that had not spawned) or energy-rich body parts (eggs in females; brain in males). In contrast, individual fish were consumed to a much greater extent, regardless of sex or spawning status, in habitats or years of low salmon availability. The proportion of biomass consumed per fish was similar for males and females, when spawning status was statistically controlled, but bears targeted different body parts: the body flesh, brain and dorsal hump in males and the roe in females. Bears thus appeared to maximize energy intake by modifying the amount and body parts consumed, based on availability and attributes of spawning salmon.