Loner lizards don't light up: The social side of lizards (w/ Video)

January 22, 2014, University of Sydney

(Phys.org) —One of the first studies conducted on young reptiles reared without contact with their siblings is challenging the assumption that only mammals and birds are shaped by social interactions.

"Our results demonstrate that rearing these animals in different environments strongly affects their ," said Cissy Ballen, a PhD candidate in the University of Sydney's School of Biological Sciences and lead author of the paper published in Animal Behaviour.

"These chameleons catch insects using a 'ballistic' rapid fire tongue movement and use dramatic colour changes to signal dominance. The lizards raised in isolation were more submissive, were slower at attacking certain food and displayed darker and duller colours than those raised with their siblings."

Most people know that to rear a baby on its own would have devastating consequences for its development. Until very recently, scientists have believed that only the 'social' species, such as birds and mammals, were disadvantaged by being reared in isolation.

It has been assumed that reptiles, as 'lower' animals, are non-social, so their behaviour is determined by their genes, not by their interactions with members of the same species.

The research was conducted using young veiled chameleons (Chamaeleo calyptratus), large tree-dwelling lizards native to Yemen and Saudi Arabia that are popular as pets and in zoos. While their mother usually leaves after giving birth, they often encounter their brothers and sisters as they grow up.

The chameleons were raised alone or in groups of four.

In addition to their slower food attack times and duller colours when young isolated chameleons had contact with siblings, they fled and curled into balls. In contrast, those reared in groups interacted and exhibited their colours in a competitive display.

"Young chameleons, like many reptiles, often engage in intense combat with each other. The absence of this opportunity appears to slow the development of behaviours that help the lizard intimidate rivals and succeed in acquiring food."

Early research assumed that reptiles' behavioural traits were highly stereotyped and fixed, differing between species but not changing in response to the conditions that an individual experienced during its lifetime. However, there is emerging evidence of complex social systems among some lizards, including the ability to solve cognitive tasks, exhibit social learning and demonstrate specific variations in mating behaviour.

"The idea of lizards as machine-like creatures who do not respond to local conditions is being replaced by a new appreciation of the subtlety and flexibility of reptile behaviour as influenced by their local environment and genetic factors," said Ballen.

"Future research could explore the possibility that some reptiles are far more responsive to social cues than we expect.

"Our results also have obvious implications for the captive rearing of reptiles. These animals are commonly raised by zoos, private keepers and pet owners in , under the assumption that are irrelevant to their development. Our results call that into question and suggest that for many , an environment rich in may provide important benefits for their wellbeing."

Explore further: Ancestor of snakes, lizards likely gave birth to live young

More information: Cissy Ballen, Richard Shine, Mats Olsson, Effects of early social isolation on the behaviour and performance of juvenile lizards, Chamaeleo calyptratus, Animal Behaviour, Volume 88, February 2014, Pages 1-6, ISSN 0003-3472, dx.doi.org/10.1016/j.anbehav.2013.11.010.

Related Stories

Ancestor of snakes, lizards likely gave birth to live young

December 17, 2013

The ancestor of snakes and lizards likely gave birth to live young, rather than laid eggs, and over time species have switched back and forth in their preferred reproductive mode, according to research published in print ...

Research finds that lizards are fast learners

October 17, 2012

(Phys.org)—An Australian lizard, the Eastern Water Skink, has dispelled a long held myth that reptiles are slow learners. Researchers studying the lizard have found they do have the ability for rapid and flexible learning, ...

Tiny chameleons discovered in Madagascar

February 15, 2012

Four new species of miniaturized lizards have been identified in Madagascar. These lizards, just tens of millimeters from head to tail and in some cases small enough to stand on the head of a match, rank among the smallest ...

Hotter homes produce smarter babies

January 12, 2012

(PhysOrg.com) -- A hotter home appears to produce babies with better cognitive abilities - but before you turn up the home heater to make your baby brainier, the research was conducted on the Australian lizard Bassiana duperreyi ...

Recommended for you

Some female termites can reproduce without males

September 24, 2018

Populations of the termite species Glyptotermes nakajimai can form successful, reproducing colonies in absence of males, according to a study published in the open access journal BMC Biology.

Photosynthesis discovery could help next-gen biotechnologies

September 24, 2018

Researchers from The University of Queensland (UQ) and the University of Münster (WWU) have purified and visualized the 'Cyclic Electron Flow' (CEF) supercomplex, a critical part of the photosynthetic machinery in all plants, ...

How fruits got their eye-catching colors

September 24, 2018

Red plums. Green melons. Purple figs. Ripe fruits come in an array of greens, yellows, oranges, browns, reds and purples. Scientists say they have new evidence that plants owe their rainbow of fruit colors to the different ...

Custom circuits for living cells

September 24, 2018

A team of Caltech researchers has developed a biological toolkit of proteins that can be assembled together in different ways, like Legos, to program new behaviors in cells. As a proof-of-concept, they designed and constructed ...

Birds' voiceboxes are odd ducks

September 24, 2018

Birds sing from the heart. While other four-limbed animals like mammals and reptiles make sounds with voiceboxes in their throats, birds' chirps originate in a unique vocal organ called the syrinx, located in their chests. ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.