Shumen University, Shumen, Bulgaria.
University of Vienna, Vienna, Austria.
PeerJ. 2022 Jul 15;10:e13647. doi: 10.7717/peerj.13647. eCollection 2022.
On land, the amphibians interact with the environment in a complex way-even small changes in the physiological conditions may significantly impact the behaviour and . In ectothermic tetrapods, the transition from inactive to active phase may be related to important changes in their thermal status. We studied the thermal ecology of adult Balkan spadefoots ( Karaman, 1928) in northeastern Bulgaria. These toads spend the daytime buried between 10 and 15 cm in sandy substrates, and emerge after sunset. On the substrate, their thermal energy exchange is defined by the absence of heat flow from the sun. Secondary heat sources, like stored heat and infrared radiation from the soil play an important role for the thermal balance of the active spadefoot toads. At the beginning of their daily activity, we measured substrate temperature (at a depth of 11-12 cm), toad's surface body temperature, and also provided thermal profiles of the animals and the substrate surface in their microhabitats. In animals which recently emerged from the substrate, the temperature was comparatively higher and was closer to that of the subsoil on the spot. After that, body temperature decreased rapidly and continued to change slowly, in correlation with air temperature. We detected a temperature gradient on the dorsal surface of the toads. On the basis of our measurements and additional data, we discuss the eventual role of air humidity and the effects of surface and skin water evaporation on the water balance and activity of the investigated toads.
在陆地上，两栖动物以复杂的方式与环境相互作用——即使生理条件的微小变化也可能对它们的行为产生重大影响。在变温四足动物中，从不活跃到活跃状态的转变可能与它们热状态的重要变化有关。我们研究了保加利亚东北部巴尔干铲足蟾（ Karaman，1928）成体的热生态学。这些蟾蜍白天会在 10 到 15 厘米深的沙质基质中掩埋自己，然后在日落后出现。在基质上，它们的热能交换是由太阳没有热流造成的。次要热源，如储存的热量和土壤的红外辐射，对活跃的铲足蟾的热平衡起着重要作用。在它们日常活动的开始，我们测量了基质温度（在 11-12 厘米的深度）、蟾蜍的表面体温，还提供了动物和微生境中基质表面的热廓线。在刚刚从基质中出现的动物中，温度相对较高，并且更接近该地点的地下温度。之后，体温迅速下降，并继续缓慢变化，与空气温度相关。我们在蟾蜍的背部表面检测到温度梯度。基于我们的测量结果和其他数据，我们讨论了空气湿度的潜在作用以及表面和皮肤水分蒸发对所研究蟾蜍的水分平衡和活动的影响。
