Movement, behaviour and microclimate habitat requirements of endangered grassland birds in a warming world

Ramos, Rita Alexandra Fineza (2024) Movement, behaviour and microclimate habitat requirements of endangered grassland birds in a warming world. Doctoral thesis, University of East Anglia.

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Abstract

Species distribution worldwide is intricately connected to the environmental conditions’ individuals experience. Despite many ecological studies tackling this subject, many overlook the inclusion of information at the scale individuals experience their environment, resulting in inaccurate estimations of species range shifts. This thesis addresses this gap by utilizing state-of-the-art tracking devices and analysis software to investigate the movement strategies, fine-scale habitat utilization, and microrefugia preferences of an endangered grassland bird. This study focused on the little bustard (Tetrax tetrax), benefiting from data from a long-term tracking project in the Iberian Peninsula. Additionally, the partial migratory behaviour of the species provides unique insights into the effects of environmental changes on movement strategies, both at broader and more detailed scales.

At a fine scale, my investigation into little bustards' microclimate refugia use revealed their active search for cooler sites characterized by heterogeneous vegetation cover. I further investigated the consistency in little bustard's migratory behaviour and the significance of microclimate refugia in regulating migratory timings. My findings revealed that post-breeding migration timing correlates with the declines in food availability, although microclimate refugia availability may extent the breeding season for longer. Finally, when looking at the environmental niche of this species, I identified a gradient of temperature and microclimate refugia availability as primary determinants, suggesting a crucial role for refugia in niche tracking and adoption of different migratory strategies.

A broader analysis of the species foraging movements uncovered year-round movements dependent on sparsely and randomly distributed resources. Breeding and winter movements were associated with higher soil and vegetation moisture levels, while the post-breeding season, showed optimal search patterns in more productive areas.

Overall, this thesis enhances our understanding of the importance of fine-scale environmental variability in species distribution and movement strategies and also provides new tools for planning conservation measures to create more resilient habitats.

Item Type:	Thesis (Doctoral)
Faculty \ School:	Faculty of Science > School of Environmental Sciences
Depositing User:	Chris White
Date Deposited:	05 Nov 2024 09:56
Last Modified:	05 Nov 2024 09:56
URI:	https://ueaeprints.uea.ac.uk/id/eprint/97496
DOI:

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