Sumbera Radim, Zelová Jitka, Kunc Petr, Knízková Ivana, Burda Hynek
Department of Zoology, Faculty of Biological Sciences, University of South Bohemia, Branisovská 31, 370 05, Ceské Budejovice, Czech Republic.
Physiol Behav. 2007 Oct 22;92(3):526-32. doi: 10.1016/j.physbeh.2007.04.029. Epub 2007 Apr 29.
Furred subterranean mammals face the problem of dissipating heat to the environment because high humidity and absence of air flow in sealed belowground tunnels constrain heat loss from body by convection and evaporation. In order to detect body areas responsible for heat loss, surface temperatures in two species of African mole-rats were measured at different ambient air temperatures by infrared thermography. Fur characteristics were also evaluated. Thinner pelage of the ventrum, its moderate temperature and large size suggest that ventral side of the body is the main thermal avenue for heat loss in both species. Interspecific differences could be explained by different fur characteristics connected with social thermoregulation. Compared to the social Fukomys mechowii, the solitary Heliophobius argenteocinereus has denser and longer fur on most of its body; its surface temperature was thus lower than in F. mechowii at lowered ambient temperatures. On the other hand, the denser and longer hair cover in H. argenteocinereus impedes heat dissipation at highest ambient temperatures (and probably also during digging activity) resulting in increase of core body temperature. H. argenteocinereus seems to be more sensitive to overheating than F. mechowii. At lower air temperatures, the social species may uses huddling to combat hypothermia.
穴居有毛哺乳动物面临着向环境散热的问题，因为封闭的地下隧道中湿度高且没有气流，限制了通过对流和蒸发从身体散热。为了检测负责散热的身体部位，通过红外热成像在不同环境空气温度下测量了两种非洲鼹形鼠的体表温度。还评估了皮毛特征。腹部皮毛较薄、温度适中且面积较大，表明身体的腹侧是这两个物种散热的主要热通道。种间差异可以用与社会体温调节相关的不同皮毛特征来解释。与群居的梅氏非洲鼹鼠相比，独居的银灰盲鼹身体大部分部位的皮毛更浓密、更长；因此，在环境温度降低时，其体表温度低于梅氏非洲鼹鼠。另一方面，银灰盲鼹更浓密、更长的毛发覆盖在最高环境温度下（可能在挖掘活动期间也是如此）会阻碍散热，导致核心体温升高。银灰盲鼹似乎比梅氏非洲鼹鼠对过热更敏感。在较低气温下，群居物种可能会通过挤在一起抵御体温过低。
