TO BREED OR NOT TO BREED - AN ANALYSIS OF THE SOCIAL AND DENSITY-DEPENDENT CONSTRAINTS ON THE FECUNDITY OF FEMALE BADGERS (MELES-MELES)
TO BREED OR NOT TO BREED - AN ANALYSIS OF THE SOCIAL AND DENSITY-DEPENDENT CONSTRAINTS ON THE FECUNDITY OF FEMALE BADGERS (MELES-MELES)
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DOI：
10.1098/rstb.1992.0157
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发表时间：
1992-12-29
期刊：
影响因子：
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通讯作者：
MALLINSON, PJ
中科院分区：
文献类型：
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作者：
CRESSWELL, WJ;HARRIS, S;MALLINSON, PJ
来自尸检、种群密度估计和长期捕获-标记-重新捕获研究的数据被结合在一起，以观察英国獾的繁殖行为模式和导致繁殖失败的社会因素。研究结果被用来评估保护发情雌性(相对于保护食物资源)是否最好地解释了獾的领土行为和社会组织这一假设。英国獾有两个生殖活动高峰，一个是产后立即繁殖，另一个是夏季/秋季。这两个时期恰逢排卵的两个高峰，在冬末/春季，携带囊胚的母猪数量急剧增加，一岁母猪在6月达到渐近线，年龄较大的母猪在4月达到渐近线。从它们对整体生产力的贡献来看，冬/春交配比夏/秋交配重要得多，占一岁母猪秋季囊胚总数的65%，占老年母猪秋季囊胚数的71%。这两个交配期的相对重要性反映在成年雄獾咬伤的季节性格局上；1-3月的轻微咬伤是8-10月的2.3倍，中度-广泛咬伤的频率是3.1倍。在所研究的种群中，出生前和出生后的损失很高，繁殖周期的各个阶段都会发生生殖失败，因此实现的潜在生产力不到30%。事实上，22%的母猪没有发育出胚泡；这些母猪的体重较低，体脂较少，肾上腺较大，健康状况较差，咬伤评分高于有胚泡的母猪。只有4400头成年母猪植入囊胚，直到妊娠结束。然而，要识别出母猪有没有继续植入囊胚的特征就不那么容易了。最后，35%的产下幼崽的母猪提前停止了哺乳，这一整窝产仔的损失被认为是由于优势母猪的杀婴。附属物的存在与年轻母猪生产力的提高有关，这被认为是因为附属物使年轻母猪及其幼崽能够避免年龄较大、更具优势的母猪的攻击。生活在大型社会群体中对成年雄性或雌性母猪没有净繁殖收益，随着群体规模的增加，生产力(每个成年人)下降。尽管没有亲子鉴定来评估群体生活的个体收益，但没有配偶守卫，以及绿帽子和混合父子产仔的频率表明，交配不是占主导地位的公猪的唯一特权，甚至可能不是主要特权。到目前为止，这些数据质疑了獾的社会组织进化为垄断发情雌性的假说。
Data from post-mortem examinations, population density estimates and long term capture-mark-recapture studies have been combined to look at the pattern of reproductive behaviour and the social factors leading to reproductive failure in badgers in Britain. The results are used to evaluate whether the hypothesis that the defence of oestrous females (as opposed to defence of food resources) best explains territorial behaviour and the social organization of badgers.Badgers in Britain have two peaks of reproductive activity, one immediately post partum and one in the summer/autumn. These coincide with two peaks of ovulation, and in the late winter/spring there is a steep rise in the number of sows carrying blastocysts, to reach an asymptote in June for yearling sows and April in older sows. Measured by their contribution to overall productivity, winter/spring matings were much more important than summer/autumn matings, contributing 65% of total autumn blastocysts in yearling sows and 71% of autumn blastocysts in older sows. The relative importance of the two mating periods is reflected in the seasonal pattern of bite wounding in adult male badgers; minor bite wounding in january-March was 2.3 times as frequent as in August-October, and moderate-extensive bite wounding was 3.1 times more frequent.In the populations studied, pre- and post-natal losses were high, with reproductive failure occurring at all stages of the breeding cycle, so that less than 30% of potential productivity was achieved. Indeed 22% of sows failed to develop blastocysts; these had a lower body mass, less body fat, larger adrenal glands, poorer health and higher bite wound scores than sows with blastocysts. Only 4400 of adult sows implanted their blastocysts and proceeded to the end of pregnancy. However, it was less easy to identify features characteristic of sows that did or did not go on to implant their blastocysts. Finally, 35% of sows that produced cubs ceased lactation early, and this loss of entire litters was thought to be due to infanticide by dominant sows. The presence of annexe setts correlates with increased productivity in younger sows, and this is thought to be because annexe setts enable younger sows and their cubs to avoid the aggression of older, more dominant sows.Living in large social groups has no net reproductive gain for adult males or females, and there was a decline in productivity (per adult) with increasing group size. Although paternity measures were not available to assess the individual gains from group living, the absence of mate guarding and the frequency of cuckoldry and of mixed-paternity litters suggests that mating is not the sole, or probably even the major, prerogative of a dominant boar. The data so far question the hypothesis that the social organization of badgers evolved to monopolize access to oestrous females.