Landscape energetics in the wild Carneddau ponies: behaviour, movement and associated physiological trade-offs.

Abstract

Animals move across landscapes that are heterogenous in habitat properties, such as resource availability, predation pressure, species competition, human presence, and topography. Topography has seldom been studied as a driver of animal movement, space use and behaviour, despite the energetic costs associated with walking across an incline, especially in larger bodied species. Therefore, large bodied species should be particularly sensitive to the costs of moving across topographically complex landscapes. The objective of this thesis is to understand the impacts of the topographic characteristics of home ranges such as elevation, slope and terrain ruggedness on space use, behaviour, and physiological trade-offs of the Carneddau ponies, a free ranging population in the Welsh mountains. I conducted focal watches to quantify the behaviour of adults across the landscape. Additionally, I used GPS points from group follows to evaluate home range characteristics, space use and energetic costs of paths. Social groups were smaller at higher elevation. Home range characteristics also varied across social groups in terms of elevation and slope and ruggedness. Some, but not all, groups avoided steep and rugged areas within their home ranges. However, despite variation in home range topography, there were no differences in the energetic costs of paths across groups. Furthermore, groups in more rugged areas travelled shorter distances, spent more time resting and less time moving (especially females). Faecal thyroid and glucocorticoid metabolite concentrations did not vary between groups. But both metabolites were linked to seasonality, female reproductive status, and group size. Pregnant females had higher concentrations of both T3 and glucocorticoid metabolites than non-pregnant females. T3 levels were high in late winter, declined with warming temperatures and then increased with the grass flush in late spring. Taken together, these results suggest that groups can effectively mitigate against travel costs in high and steep home ranges, illustrating strategies to minimise cost of transport by using efficient travel routes. This study was able to demonstrate how this pony population alters their space use and behaviour to avoid supplementary energetic costs from living in a mountainous landscape, and provides support for future studies on how other species adapt to heterogenous landscapes.

Date of Award	1 Aug 2022
Original language	English
Awarding Institution	The University of Manchester
Supervisor	Jonathan Codd (Supervisor) & Susanne Shultz (Supervisor)