Growth and variation in the bacula of polar bears (Ursus maritimus) in the Canadian Arctic
Growth and variation in the bacula of polar bears (Ursus maritimus) in the Canadian Arctic
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DOI：
10.1017/s0952836904005606
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发表时间：
2004-09-01
影响因子：
2
通讯作者：
Miller, EH
中科院分区：
文献类型：
--
作者：
Dyck, MG;Bourgeois, JM;Miller, EH
在许多种类的arctoid食肉动物中，阴茎骨的结构和生长已经得到了很好的描述。这项研究提出了第一个广泛的分析杆状生长和变化的熊（熊科），基于871杆状的北极熊（858已知年龄），在加拿大北极地区拍摄1994年至1997年。1岁熊（n = 34）的眼长、最大直径和质量分别为109 mm、5.93圈和2.68 g，10岁以上熊（n > 200）的眼长、最大直径和质量分别为190 mm、18.7 mm和20.4 g。在成年鱼中，鳃的长度约为体长的8%。杆状病毒的大小中等变异：长度、直径和质量（1/3）的变异系数分别为5.2%、10.0%和5.4%（质量为16.3%）。没有明显的地域差异。Bacula在8-9岁时达到渐近大小。在生理性成熟期（接近6岁），杆状体的长度、直径和质量分别为体长的89%、73%和62%（接近体长的95%）。对这些发现的解释必须等待北极熊求偶和交配的行为和生理信息，以及其他熊类动物的比较数据。
Structure and growth of the baculurn (os penis) in arctoid carnivores have been well described for many species. This study presents the first extensive analysis of bacular growth and variation for bears (Ursidae), based on 871 bacula of polar bears Ursus maritimus (858 of known age) that were shot in the Canadian Arctic from 1994 to 1997. Bacular length, maximal diameter and mass increased from 109 mm, 5.93 turn and 2.68 g respectively in 1-year-old bears (n = 34) to 190 (maximum 222) mm, 18.7 (24.4) mm, and 20.4 (31.9) g respectively in bears > 10 years of age (n > 200). Bacular length is similar to8% of body length in adults. Bacula were moderately variable in size: coefficient of variation for length, diameter, and mass(1/3) were 5.2, 10.0 and 5.4% respectively (16.3% for mass). No geographic variation in size was apparent. Bacula reached asymptotic size at 8-9 years of age. At physiological sexual maturity (similar to6 years of age), bacula were at 89, 73 and 62% of asymptotic length, diameter and mass respectively (compared with body length at similar to95%). Interpretation of these findings must await behavioural and physiological information on courtship and copulation in the polar bear, and comparative data on other ursids.