All posts by Harsimran Singh

About Harsimran Singh

I am Harsimran Singh from India. I am interested in systematics, ecology and evolution. My keen interest is in how species diverge especially in mountain landscape. Model organisms that I consider for my study are amphibians and reptiles. I am applying morphometric, acoustic and behavioral traits. For my PhD I am working on taxonomy of Pyraustinae and Spilomelinae moths (Crambidae) from Western Ghats and North East India. Photography, filming, music, travelling and reading is what drives my life.

Prince of Thar–Sands of Time…

An adult nipping grass in the morning; notice the bluish tinge on the inner side of the thigh and dorsal part of tail.

An adult nipping grass in the morning; notice the bluish tinge on the inner side of the thigh and dorsal part of tail.

Here is Saara hardwickii , spiny tailed lizards. I observed these lizards in their natural habitat, in the Thar desert in Indian state of Rajasthan. It’s a medium-sized lizard which dwells in semi-arid to arid landscapes of northern India, Pakistan and some regions beyond. A drab colored lizard with a pug head and a distinct fleshy and spiny tail.

Habitat fragmentation and hunting for its tail is the main reason for its dwindling numbers. Folklore has it that its tail has aphrodisiac powers, so its tail is cut and ‘oil’ extracted from it and consumed for the intended purpose.

Interestingly, like iguanas, these lizards also live in a social structure, a ‘society’ composed of adults as well as young ones. They live in ground burrows or termite mounds. Spiny-tailed lizards are diurnal; their activity starts around early morning sun and when the sun sets, surprisingly not even a single individual can be seen! A considerable ontogenic shift in dietary inclination towards herbivory can be seen. Adults feed on grass or diminutive terrestrial flora, whereas young ones are omnivorous, feeding on arthropods.

This fellow was just out of its home and carefully observing its habitat.

This fellow was just out of its home and carefully observing its habitat.

Meanwhile in a Parallel Universe…

At the other end of the world in the Indo-Malayan realm (in India, down south in the sky islands of Western Ghats), a Calotes rouxii male is advertising itself. He is displaying his bright red head on its black body. Even the dewlap region is almost black. Facial region is almost completely bright red along with nuchal and spinal crest.  Male display of this lizard is like many Anolis sp. A male typically does some pushups , ducks and bobbles his head to display his dominance in physical prowess and colour.

Calotes rouxii male.

Calotes rouxii male.

Female or juvenile male of Calotes rouxii.

Female or juvenile male of Calotes rouxii.

Calotes rouxii male

Calotes rouxii male

Dragons from the Old World

The Neotropical and Oriental realms both were once a part of Gondwanaland. Interestingly, both of these realms exhibit same ‘type’ of lineages occupying equivalent niches. Boas dominate the Neotropical zone whereas pythons flourish in the Oriental. Similarly, in the Old World (or Oriental or Indo-Malayan realm), there are lizards belonging to family Agamidae which exhibit uncanny parallels to Anolis sp. in their natural history.

CSC_5284One example is from Yelagiri Hills in the Eastern Ghats region of the Indian state of Tamil Nadu. This is Psammophilus dorsalisDuring the breeding season, males of this species turn their drab and dull dorsal region to bright yellow or red to impress conspecific females. The brighter the male, the more chance he has to win over females. Males display such behavior for the entire day; at night these lizards hide under rocks.

When equally bright males encounter each other, competition is settled by ‘ducking’ heads and throwing off the opponent from the rock.