GULF TIMES (Doha, Qatar) 01 January 11 Study finds omnivorous side of strictly-herbivorous dhub (Bonnie James)

The first evidence of scavenging behaviour in the spiny-tailed lizard (Uromastyx aegyptia microlepis), traditionally considered a strict herbivore, has been unveiled by a group of researchers from Qatar, Spain and France.

The study on the lizard (locally known as dhub), based on a population in the Qatar desert, explored the hypothesis that the animal may behave as an omnivore under conditions of limited food availability.

The results of the study were presented at the Qatar Foundation Annual Research Forum held recently in Doha.

The researchers were Aurora Castilla, Renee Richer, Anthony Herrel, April Ann Torres Conkey, John Tribuna, Mohamed al-Thani, and Rita Chan.

The participating institutions were Forest Technology Centre of Catalonia, Solsona, Spain; National Museum of Natural Sciences, Madrid, Spain; Weill Cornell Medical College in Qatar; Museum national D’Histoire naturelle, France; Carnegie Mellon University in Qatar; Qatar University; and Qatar Veterinary Center.

The researchers pointed out that optimal foraging theory predicts flexibility in feeding behaviour which enables species to survive in harsh environments where food resources may be scarce and unpredictable in space and time.

Upon examining the diet of the lizard based on 294 faecal pellets collected in the field, they found remains of mammals, reptiles, birds and insects.

“We also found significant differences between our study zones in the type of food consumed by lizards,” they explained.

This highlights the importance of environmental conditions and human activity on lizard behaviour.

The consumption of vertebrate carcasses was only detected in the study area located near the main road, suggesting that scavengers may benefit from the availability of dead animals along roads that result from collisions with vehicles.

The consumption of barley by lizards was observed only in the study area near a camel farm, suggesting that lizards can also benefit from the food provided by farmers to livestock.

“Our findings of scavenging behaviour have important implications for the application of management actions, such as the provisioning of carcasses near the lizard colonies,” the researchers said.

That may help preserving the species in situations of extreme food scarcity under the threat of global warming. Lizards near farms can also benefit from extra food of human origin.

“Because the current decrease in, and loss of biodiversity is a real threat, the identification of different tools that may help to reduce the rate of biodiversity loss is crucial,” they added.

The dhub can grow to a length of 65cm and usually lives in loose colonies, which may extend over large areas, depending on the availability of food.

Feeding on shrubs, the spiny-tailed lizard never drinks water and has special glands that help its body to dispose of uric acid.

Despite its dragon-like appearance, the dhub is a very placid animal that prefers to flee rather than enter into conflict.

If cornered, however, it can give painful blows with its spiny tail. With its strong jaws that have no teeth, but possess sharp bone plates, it can give a nasty bite.

The dhub used to be a welcome source of protein for the bedouin and the strong leather of its skin was widely used.
Study finds omnivorous side of strictly-herbivorous dhub

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