A Behavioural Study of Pristimantis and Phyllomedusa frogs in the Amazon (by William Howell, intern)
5 September 2010
Hi! This is Will from the University of East Anglia (UEA) in the UK.
When I decided to make the journey to Peru and intern with Fauna Forever a big influence came from hearing about the support they offer to students conducting final year research projects.
Being offered the opportunity to collect field data for my dissertation in such a remarkable and unique study location, with the help and support of experts in the field, was simply too good to pass up. So firstly, I would like to thank all of the FF team for their support and tutoring activities during my time in Tambopata, especially Brian who helped open my eyes to a world of possibilities in studying herpetology and from whom I learnt so much.
I first became interested in the Amazon and particularly tree frogs after studying them in my 4th year of school and ever since then I have always wanted to go to the Amazon rainforest and see the many beautiful and inspirational frogs that live there! Given that I am heading into my final year in higher education (at UEA) it seemed the perfect opportunity to relate my degree course to a group of animals that I am truly passionate about.
My dissertation will set out to assess the influences of various environmental factors on the behaviour of two Genus of frog, namely Pristimantis and Phyllomedusa. The ultimate aim of this thesis is to expand upon the ideas already put forward by many herpetologists and other animal scientists about the effect of the lunar cycle on animal activity, and will also seek to assess the relationship between amphibian activity and levels of relative humidity and air temperature.
The following is just a brief extract from my research proposal highlighting the project’s main aims and objectives.
‘The majority of our understanding of these frogs is based around behaviour and morphology, with the works of Wente and Phillips and those of Gerhardt et al. being at the forefront of the literature. These researchers among others have looked extensively at their mating behaviour, the variety and seasonal changes in morphology of amphibians, and in more recent years the impacts of habitat fragmentation and the prevalence of a fungal disease called Chytridiomycosis that is decimating many amphibian populations around the world. My research project seeks to examine both male calling behaviour and morphology in Pristimantis and Phyllomedusa, two Genus of frog that have not been widely studied from a behavioural-ecological perspective, to expand on the knowledge we have already, and to determine if there are any relationships to be found between phenotypic morphology and mating success. It is also my intention to determine if there is an influence of the lunar cycle, humidity and temperature on the activity of these species. The more that can be learnt and understood about these frogs the more can be done to conserve them in the wild.’
The data collection methods for this project were simple but reliable, using a Dictaphone to record vocalisations, a hygrometer to record humidity, and a thermometer to record the temperature. I recorded frog calls during the evening from about 17:30 onwards. Over the course of the fieldwork, I managed to collect well over 20 hours of data to analyse back in the UK.
With the help of Brian and some equipment from the Fauna Forever herpetology equipment bin, I was able to construct a small open-air enclosure for a male Phyllomedusa palliata, so that I could more easily study the process of colour change in the individual between day and night, and also to examine the behaviour when introduced to another male presenting either conspecific colouration or heterospecific colouration. The aim of this smaller study is to delve a bit deeper into behavioural ecology when assessing the importance of colouration or colour signalling as an indicator of being a conspecific or heterospecific male. There has been a great deal of research into colour signalling in animals, and the ability to change colour. A paper by Chaney et al. (Facultative Mimicry: Cues for colour change and colour change accuracy in coral reef fish.) examines the factors behind colour change and covers the reasons for colour change in the blue-striped fang-blennie (a type of fish). With papers such as this and others, I am hoping to pull together the broader ideas behind behavioural ecology and contribute to a better understanding of the behaviours present in these animals.
I am now back home and in the process of analysing my data. Wish me luck!