Policromatismo y desempeño térmico en atractus crassicaudatus (duméril y bibron, 1854), (serpentes: dipsadidae): un estudio de aproximación sobre su aptitud darwiniana relativa

Abstract

The savannah snake A. crassicaudatus is a snake with a wide distribution in the cundiboyacense regions of Colombia, as well as a wide chromatic variation so far insufficiently understood in terms of thermal performance, phenotypic and physiological plasticity, especially during photophase. This study focused on exploring the thermoregulatory strategies of A. crassicaudatus at the intrapopulational level, with the objective of evaluating the thermal performance and relative Darwinian fitness of this species as a function of its polychromatic variation and to clarify whether such variation could affect its response and survival capacity in the face of thermal variability events. In this work, the morphotypes of the species were characterized for the first time at the population level (Mongue, Chipaque, Cundinamarca) and statistically significant findings related to its thermal adaptation and thermoregulatory behavior at the intra- population level were reported. The presence of thermal melanism was demonstrated for the first time for this species and was associated with independent physiological adaptations at the morphotype level related to phenotypic plasticity in the species, highlighting its adaptive resilience in the colonization of mountain habitats. In addition, the hours of greatest optimality in thermoregulation during photophase (9am- 11am) were identified for the study population. And knowledge of the natural history of the species in terms of its reproductive season, number of egg clutches, maximum size reported for the species, first record of in situ reproduction and first ex situ birth for the species was expanded. Overall, these results underline the importance of considering phenotypic and physiological plasticity in the adaptation of the species to changing environments, providing valuable information to understand its adaptive success and its ability to colonize diverse thermal habitats. This work enriches the natural history of the species and demonstrates for the first time the phenotypic and physiological plasticity in A. crassicaudatus, highlighting the physiological variations of thermoregulation at the morphotype level.