Natural history of Valentin’s rock lizard (Darevskia valentini) in Armenia

Abstract

Valentin’s rock lizard ( Darevskia valentini ) is suggested to be the parent for several parthenogenetic species (e.g., D. armeniaca , D. bendimahiensis, D. sapphirina , and D. unisexualis ) that evolved through hybridization. Complex evolutionary processes (including reticulate evolution) are occurring within the areas where Valentin’s rock lizard coexists with these and other rock lizards. Hence, a detailed biological specification of this species is important for understanding how vertebrates evolve. Valentin’s rock lizard is a long-lived (up to 9 years), small diurnal lizard with larger females than males, which is unlike other species of the genus. Their relatively large eggs and early reproduction period, which occurs just after emergence from winter shelters, are adaptations for living in a high elevation climate (higher than 2 000 m a.s.l.). Their body temperatures (31–32 °С) are comparable to body temperatures of rock lizards living in milder climates, though female body temperature is more dependent on substrate temperature and basking due to their lower activity than that found in males. Population density fluctuates from several individuals to several hundred per hectare and is not affected by parthenogen coexistence, although hybrids do occur in sexually biased populations where males are more common than females. The male home range is larger than that of females, though these home ranges broadly overlap. Prey is not limited in the mountain meadows and Valentin’s rock lizards feed on a great variety of arthropods. Infanticide occurs in high-density populations.

Double-check in Lizard Age Estimation: Use of Phalanx Bone and Keratin Claw Sheath Lamellas

“…In the course of our studies (Galoyan et al, 2019a(Galoyan et al, , 2019b, we have noticed that dermal structures on the dorsal part of the claw sheath are multilayered, and we have suggested that these layers could be useful for age estimation in lizards. We put forward that the proposed procedure might be an effective supplementary method accompanying the skeletochronological method, as it may allow for the use of two different structures placed on the same finger to doublecheck the esteemed age.…”

Fine-scale analysis of habitat occupancy by Kura lizard (Darevskia portschinskii) and its daughter parthenogenetic form (Darevskia dahli)

“…The reason for this is not clear. It may be competition for food: rock lizards eat arthropods of appropriate size (Darevsky 1967;Tsellarius and Tsellarius 2001;Galoyan et al 2019). Like other ectothermic organisms feeding on small invertebrates (e.g., Kuzmin and Tarkhnishvili 1992), they hardly can seriously affect the abundance of insects; rather, a high concentration of animals may decrease the hunting success.…”

Double-check in lizard age estimation: use of phalanx bone and keratin claw sheath lamellas

“…Relying on longitudinal monitoring, ecological and behavioural studies suggest that toe-clipping and distal nger phalanx analysis should be used to collect the material [11][12][13][14][15]. These methods allow the researchers to conduct a life-long study to estimate the growth pattern of individuals.…”