The Curious Case of Climbing Newts

My eye was drawn to a post in the UK Amphibian and Reptile Groups Discussion Forum on Facebook which reported that as many as 50 Palmate Newts (Lissotriton helveticus) were found in reeds and low vegetation as high a three feet—nearly a metre—from the ground. Various comments followed as to why they may have been doing that when their breeding pond was close by. One of the comments was from Henrik Bringsøe in Denmark pointing out that he had written a paper on similar behaviour he and others had observed in the Smooth or Common Newt these days known as Lissotriton vulgaris, rather than the Triturus vulgaris we grew up with.

Bringsøe reported newts being found on the trunks of trees, on leaves and branches in vegetation about 40-50 cm above the ground and on the top of dead rushes at the edge of a pond. One was found 180 cm above the ground on the branch of an alder. Another, which was possibly attracted to invertebrates around a lamp, was found at a height of 2 metres on the wall of a house.

From Bringsøe, 2013

An obvious question is why this phenomenon has been so rarely observed. I could find no mention in either of the old standard books on British amphibians and reptiles, Smith and Frazer. Has it simply been missed or not reported?

There are all sorts of possible explanations for this little-reported climbing behaviour by amphibians which seem so ill-equipped for any sort of arboreal life. Indeed, there may be more than one reason with seeking food on vertical surfaces an obvious example. One suggestion that has not previously been raised might pertain to the climbing into vegetation near breeding ponds. Newts—both males and females—are known to use pheromones in courtship in their breeding ponds. Could it be that they are using an elevated position to ensure pheromones are further and more widely distributed in the surrounding air currents rather than relying on short-range diffusion close to the ground? Importuning—I’m here, come and get me’—could be what some of the climbing newts are up to, the unpaired ones climbing into reeds and shrubs to advertise their presence. 

Bringsøe H. 2013. Height-seeking habits of the Smooth Newt, Lissotriton vulgaris – a neglected behavioural trait. Mertensiella 19, 131-138.

Dusenbery DB. 1992. Sensory Ecology. New York: WH Freeman.

Frazer. D. 1983. Reptiles and Amphibians in Britain. London:Bloomsbury.

Smith M. 1954. The British Amphibians and Reptiles. Revised Edition. London: Collins

Golden Hamsters in the wild are diurnal but in captivity are nocturnal. Do we know why?

in a previous article about Golden Hamsters, I wrote

After Rolf Gattermann’s death from cancer in 2006 at the age of 57, his team of collaborators, who had made Halle a centre of small rodent research, continued publishing their work and started new strands, including field work on the Golden Hamster in southern Turkey. One interesting paper, begun while Gattermann was still alive, reported that while in the laboratory male and female hamsters (whether derived from old line or from newly-caught individuals) are nocturnal, in the wild female hamsters are diurnal. They speculated that a balance in the environment whereby nocturnal predators (owls and foxes) are a more potent threat than diurnal ones (birds-of-prey and snakes) may be responsible.

Since then there have been a number of studies attempting to identify the stimuli which turn hamsters from diurnal in the wild to nocturnal in captivity. As far as I can see there has been no success. However, some smaller effects evoked by potential predators have been recorded. For example, hamsters exposed to the odour of domestic ferrets spent less time out of a simulated burrow. In another species, the pattern of activity was affected by the rodent community in which the hamster was living, the time out and about was shortened when there were aggressive gerbils around.

I wonder whether the nature of the housing has an effect, being reminded of the marked changes in thermoregulatory behaviour observed by Roger Avery, then in Bristol, and also by me, in lizards given different sorts of cage furnishings. The deep and dark burrow system in the wild is very different from the accommodation afforded to pet and laboratory hamsters. Sleeping quarters are not necessarily completely dark and the Golden Hamster in the wild is subject to a very different regime of light/dark periods to that in a cage. Some simple experiments could be done.

In the meantime we still do not know if the presence and perception of predators is responsible for the basic activity pattern in the wild of Golden Hamsters.

McPhee ME, Segal A, Johnston RE. 2010. Hamsters use predator odors as indirect cues of predation risk. Ethology 116, 517-523

McPhee ME, Ribbeck AE, Johnston RE. 2009. Male golden hamsters (Mesocricetus auratus) are more reactive than females to a visual predator cue. Journal of Ethology 27, 137-141

Scheibler E, Wollnik F, Brodbeck D, Hummel E, Yuan S, Zhang, F-S, Zhang X-D, Fu H-P, Wu X-D. 2013. Species composition and interspecific behavior affects activity pattern of free-living desert hamsters in the Alashan Desert. Journal of Mammalogy 94, 448-458. (Note—not on the Golden Hamster)

A Tree Skink (Lipinia vittigera) Waves its Tail

Archaeological sites are often good places to see reptiles and birds. Although Angkor Thom and Angor Wat in Cambodia were disappointing in the bird line, a skink provided some zoological interest. A Yellow-striped Tree Skink (Lipinia vittigera) advertised its presence because it persistently waved its tail with the top over the body while moving on the horizontal and vertical surfaces of the ruins. I managed to take a little video footage showing this behaviour at Angkor Thom:

When I got back to UK, I found that this behaviour had been reported by The Lizard Lab at Macquarie University in Australia, again with some footage of this lizard at Angkor Wat.

They speculated that this behaviour may be to draw the attention of predators to the expendable tail as in other lizards with conspicuous tails. Well, maybe? Could it be display or even to attract insects as a lure?

I am afraid that I disgraced myself at Angkor Thom by not recognising the site of a film scene from Tomb Raider nor, indeed, knowing that such a film had ever been made. When Angelina Jolie was mentioned, I am afraid I only vaguely recalled that she was an actress, and could never recall having seen her. In defence, I did point out that former directors of Scottish research institutes were no stranger to video games. Indeed, the late Sir Kenneth Blaxter phoned me in great excitement one day to say that he had finished his masterpiece (written in BASIC, I think) Fragmentation Bombing of ARC Headquarters. For those not born then, the Agricultural Research Council was the forerunner of the present BBSRC; its headquarters were in Great Portland Street, London before they were removed to the outer darkness of deepest Swindon.