Forest Elephant Behavioral Ecology in a Forest-Savannah Mosaic Ecosystem / L. A Jasperse-Sjolander.
Forest elephants (Loxodonta cyclotis) are an understudied species, largely due to their elusive nature and dense habitat, which are facing increasing pressure from poaching. Though Gabon has a relatively high abundance of elephants for the region, there has been a rampant increase in poaching pressu...
Saved in:
| Online Access: |
Connect to online resource |
|---|---|
| Main Author: | |
| Format: | Thesis Electronic eBook |
| Language: | English |
| Published: |
Ann Arbor :
ProQuest Dissertations & Theses,
2023.
|
| Subjects: |
| Summary: | Forest elephants (Loxodonta cyclotis) are an understudied species, largely due to their elusive nature and dense habitat, which are facing increasing pressure from poaching. Though Gabon has a relatively high abundance of elephants for the region, there has been a rampant increase in poaching pressure in recent years, with some areas declining by as much as 80% over a 10-year period. Understanding the demographic consequences of disturbances such as poaching is necessary to help manage and mitigate these anthropogenic threats, but currently, we know little about what ecological factors shape forest elephant demography and social behavior across different landscapes. Data on demography and social behavior in this critically endangered species are rare, with the exception of elephant populations in mineral-rich forest clearings, i.e., bais. Resource-rich bais allow for the formation of larger groups and can act as social arenas for elephants, in comparison to the forest understory where resources are more spatially heterogeneous and where elephant groups break apart to allow for resource partitioning. However, bais are not the only open areas that forest elephants occur in: many forest elephants exist in forest-savannah mosaic ecosystems. In these mosaic ecosystems, savannas are also resource-rich open-habitat areas that could act as social areas, affecting forest elephant group size and fission-fusion dynamics. Forest elephant group behavior has not been studied much outside of bais, thus not much is known about how these fission-fusion dynamics play out across different landscapes, such as forest-savanna ecosystems. To better assess how habitat and other environmental factors impacted group size and fission-fusion dynamics in forest elephants, we observed forest elephant groups opportunistically and with camera traps over the course of a two years (2017-2019) in the Wonga Wongue Presidential Reserve, Gabon, a unique forest-savannah mosaic habitat. The resulting two chapters from these analyses are:Chapter 1: Influence of habitat on forest elephant group size - Though we know that elephant group size can be impacted by small forest clearings (bais) it is unclear how habitat type (i.e. dense forest vs. open savannah), along with other environmental factors, impact forest elephant group size across forests-savanna mosaic ecosystems. To assess the impact of habitat on forest elephant group size, we used data from direct observations of forest elephants in both forest and savannah habitats. We also explored other environ- mental, temporal, and spatial factors that might affect group size, including time of day, season, and location are explored as potential predictors, and their influence on group type will also be explored. We found that habitat and time of day were significant predictors of group size, with larger groups forming in the savannahs than the forests, and larger groups forming later in the day. We also found that both habitat and season were significant predictors of group type, with mixed-sex groups having a higher probability of being observed in the savannah and during the long dry season, while mother-calf groups were predicted to occur most in the forest.Chapter 2: Drivers of fission-fusion dynamics in forest elephants - This chapter examines the effect of habitat, resource availability, and microhabitat on group size and composition to examine how forest elephant groups are changing on an individual level. We used data from direct observations of forest elephants in forest habitats and camera trap surveys in savannah habitats. We found that forest elephant groups were larger in the savannah, later in the day, further from streams, and closer to the forest edge. Additionally, increased fruit abundance led to larger groups in the savannah and smaller groups in the forest. These results suggest that forest elephant groups vary based on habitat, and that the influence of resource availability on group size has contrasting effects in each habitat. Additionally, when fruit is more abundant there is a higher proportion of males in the forest, indicating that males being inconsistent group members may be what's driving this difference in group size.Overall, these results add a novel understanding of the ecological factors that shape forest elephant behavioral ecology across different landscapes. Our study suggests that in savannah-forest matrix ecosystems, savannahs act as social centers where multiple groups come together to interact, establish dominance hierarchies, and socialize, similar to bais or forest clearings in more heavily forested environments. Understanding the baseline ecological drivers of social behavior in forests elephants is critically important to the management and conservation of this elusive and highly threatened species. |
|---|---|
| Item Description: | Source: Masters Abstracts International, Volume: 85-07. Advisors: Lambert, Joanna Committee members: Doak, Daniel; Abernethy, Katharine. |
| Physical Description: | 1 electronic resource (55 pages) |
| ISBN: | 9798381415032 |
| Access: | This item is not available from ProQuest Dissertations & Theses. |
| Language: | English |