Digging for answers: contributions of density- and frequency-dependent factors on ectoparasite burden in a social mammal
Digging for answers: contributions of density- and frequency-dependent factors on ectoparasite burden in a social mammal
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DOI：
10.1007/s00442-015-3494-0
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发表时间：
2016-02-01
期刊：
影响因子：
2.7
通讯作者：
Lutermann, Heike
中科院分区：
文献类型：
--
作者：
Archer, Elizabeth K.;Bennett, Nigel C.;Lutermann, Heike
由于寄生虫传播的密度依赖性，寄生虫通常被认为限制了社会性的进化。然而，群体大小和寄生虫负担之间的相关性的证据是模棱两可的，特别是对哺乳动物。宿主和寄生虫的流动性以及社会障碍可能会改变宿主接触率。在目前的研究中，我们使用的共同鼹鼠（Cryptomys hottentotus hottentotus），社会的地下啮齿动物，作为一个模型系统，探讨宿主密度和频率的接触率对体外寄生虫负担的影响。为了解决这些因素，我们使用了一种研究物种，这种物种在其地理范围内的种群密度和群间接触率自然变化。我们发现，体外寄生虫的患病率，丰度和物种丰富度下降，在区域范围内的主机密度增加。与此同时，寄生虫负担的措施增加组间接触率。体外寄生虫负担下降，在组水平的殖民地规模可能是由于增加梳理率。在评估寄生虫在社会性哺乳动物中的分布时，将群体大小与种群密度等同起来可能过于简单化。我们的数据表明，频率依赖机制可能发挥更大的作用，在人口水平上比密度依赖机制，在确定寄生虫分布在社会物种。我们建议未来的研究应明确考虑可能影响寄生虫分布的行为机制。
Due to the density-dependent nature of parasite transmission parasites are generally assumed to constrain the evolution of sociality. However, evidence for a correlation between group size and parasite burden is equivocal, particularly for mammals. Host contact rates may be modified by mobility of the host and parasite as well as social barriers. In the current study, we used the common mole-rat (Cryptomys hottentotus hottentotus), a social subterranean rodent, as a model system to investigate the effect of host density and frequency of contact rates on ectoparasite burdens. To address these factors we used a study species that naturally varies in population densities and intergroup contact rates across its geographic range. We found that ectoparasite prevalence, abundance and species richness decreased with increasing host density at a regional scale. At the same time, measures of parasite burden increased with intergroup contact rates. Ectoparasite burdens decreased with colony size at the group level possibly as a result of increased grooming rates. Equating group size with population density might be too simplistic an approach when assessing parasite distributions in social mammals. Our data suggest that frequency-dependent mechanisms may play a much greater role at a population level than density-dependent mechanisms in determining parasite distributions in social species. We suggest that future studies should explicitly consider behavioural mechanisms that may affect parasite distribution.