We examined microhabitat occupation and functional morphology of four sympatric agamid lizards(Phrynocephalus helioscopus helioscopus, P. interscapularis, P. mystaceus galli and Trapelus sanguinolentus) at three sites in the arid zone of central Uzbekistan. At two sites located in sand dunes, substrate attributes played a key role in habitat selection by three syntopic species. At a third flat, stony site, P. helioscopus selected habitat non-randomly, tending to occur close to sparse, low vegetation. Syntopic taxa were separated in morphospace, and there was a trend for taxa with proportionally longer limbs to have faster field escape speeds. Field escape distances and predator avoidance tactics differed between species, with two main escape strategies (crypsis or sand-diving following an escape sprint). We caution that broad–scale threatening processes such as over-grazing and salinity may be having a detrimental effect on microhabitat features important to terrestrial reptiles in Uzbekistan.
Key words: Agamidae, Central Asia, Microhabitat occupation, Functional morphology.We examined microhabitat occupation and functional morphology of four sympatric agamid lizards(Phrynocephalus helioscopus helioscopus, P. interscapularis, P. mystaceus galli and Trapelus sanguinolentus) at three sites in the arid zone of central Uzbekistan. At two sites located in sand dunes, substrate attributes played a key role in habitat selection by three syntopic species. At a third flat, stony site, P. helioscopus selected habitat non-randomly, tending to occur close to sparse, low vegetation. Syntopic taxa were separated in morphospace, and there was a trend for taxa with proportionally longer limbs to have faster field escape speeds. Field escape distances and predator avoidance tactics differed between species, with two main escape strategies (crypsis or sand-diving following an escape sprint). We caution that broad–scale threatening processes such as over-grazing and salinity may be having a detrimental effect on microhabitat features important to terrestrial reptiles in Uzbekistan.
Key words: Agamidae, Central Asia, Microhabitat occupation, Functional morphology.Examinamos la ocupación del microhábitat y la morfología funcional decuatro lagartos agámidos simpátridas (Phrynocephalus helioscopus helioscopus, P. interscapularis, P. mystaceus galli y Trapelus sanguinolentus) en tres localizaciones de la zona árida del Uzbekistán central. En dos localizaciones, situadas en una zona de dunas de arena, las características del sustrato tuvieron un papel clave en la selección del hábitat por parte de tres especies sintópicas. En una tercera zona, una llanura pedregosa, P. helioscopus no seleccionaba su hábitat al azar, con una clara tendencia a situarse cerca de vegetación baja y dispersa. Los taxa sintópicos estaban separados en el morfoespacio, y existía la tendencia entre los taxa con las extremidades proporcionalmente más largas a tener una mayor velocidad de huida. Las distancias de huida de campo y las tácticas de evitación de los depredadores diferían según las especies, con dos estrategias de huida principales (cripsis o enterramiento en la arena, seguidos de una carrera de escape). Hemos de advertir que los procesos amenazadores a gran escala, tales como el sobrepastoreo y la salinización pueden tener un efecto perjudicial sobre las características del microhábitat que son importantes para los reptiles terrestres de Uzbekistán.
Palabras clave: Agamidae, Asia central, Ocupación del microhábitat, Morfología funcional
