Kate D. L. Umbers

Kate D L Umbers

Contact Details

. .

Office: room 253

Banks Building (Building 44), Daley Rd

Ecology, Evolution & Genetics

Research School of Biology

College of Medicine, Biology & Environment

Australian National University

ACT 0200, Australia

phone: +61 (0)2 6125 2040

fax: +61 (0)2

skype: Kate Umbers

e-mail: kate.umbers [at] anu.edu.au

CURRENT RESEARCH

When to signal for a mate?

Females in many species must make decisions about when and how enthusiastically they should signal for a mate. In many moths females vary their signalling intensity over their lifetime. With Matthew Symonds and Hanna Kokko, I am thinking about optimal female strategies under different scenarios given that they must balance their lifetime requirement for sperm with the possibility of encountering too many or not enough males

A day moth in Cairns Botanic Gardens.
If you know the species name,
please email me and let me know!

Lizard communication

Lizards exhibit a wonderful variety of interesting behaviours when communicating with each other both in friendly and unfriendly circumstances. Scott Keogh, Eleanor Wilson and Martin Whiting & I are describing the mating system of the southern water skink (Eulamprus heatwolei) disentangling pre- and post-copulatory influences on paternity. With Louise Osborne and Scott Keogh, I am also working on publications that describe the signals tawny dragons (Ctenophorus decressi) use to recognise each other and what decisions they make when faced with antagonistic encounters.

Here is a picture of
another fabulous lizard
Boyd's forest dragon
(Hypsilurus boydii),
Far North Queensland, Australia.

photo: Kate Umbers

Frog Colouration

Contrary to my title and the photo, most frogs are not green! But what colour are frogs? And perhaps more interestingly, why are frogs the colours they are? With Scott Keogh, Dale Roberts and Phil Byrne, I am qualitatively assessing the patterns of colouration across the frog family, Myobatrachidae. This group includes the spectacularly colourful corroborree frogs (Pseudophryne corroborree & P. pengeilleyi), crucifix toad (Notden bennetii) and sunset frog (Spicospina flammocaerulea). We are exploring how their colour patterns are spread across our phylogenetic framework to try and explain the enormous colour variation in this group.

North American bullfrog (Rana catesbeiana)

certainly not part of the Myobatrachidae,
photo taken at Tiny Marsh
in Georgian Bay, Ontario, Canada

Grasshopper Parasites

In collaboration with Michelle Power, Marie Herberstein and Grant Hose I am describing the prevalence and diversity of Nematode, Nematomorph and Dipteran parasites of the Kosciuscola grasshoppers. The photo to the left shows several lengths of a single worm that folds throughout the grasshopper's entire body including the back of the head (this is a ventral view). The effect that the presence of such an enormous parasite has on the grasshopper, its host, is currently unclear but surely must have a significant impact on most aspects of its life.

A grasshopper nematode wrapped up in the
body of a Kosciuscola. The worm even makes
a home for itself in the head.

Colour change in Kosciuscola

My PhD project focused on the colour change, population structure and phylogenetics of the chameleon grasshopper (Kosciuscola tristis). Males of this species change colour from black to turquoise when their body temperature reaches 25°C. During this study I explored the function of this colour change and tested several hypotheses: thermoregulation, aposematism, female preference, male-male competition. Having collected evidence for each of these hypotheses, it seems that the most likely function for colour change in the chameleon grasshopper is in male-male combat.

This video shows male chameleon grasshoppers fighting over females while they lay their eggs in the soil (video by Dr Nikolai J Tatarnic. for more videos click here and here!). Females can't move without disturbing the process and this means that males can aggregate around them and fight each other off. Fighting is extremely unusual behaviour in grasshoppers, most of them use acoustic signalling to solve disputes instead of fierce combat. My research suggests that males involved in fights have closely matched bright turquoise colours and that they assess eachother's fighting ability through the brightness of their colour.

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