Tesi etd-03232012-131857 |
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Tipo di tesi
Tesi di laurea specialistica
Autore
SERRA, VALENTINA
URN
etd-03232012-131857
Titolo
Behavioural ecology of the red collared brown lemur (Eulemur collaris): comparison between groups living in well preserved and degraded littoral forest fragments, in South-eastern Madagascar
Dipartimento
SCIENZE MATEMATICHE, FISICHE E NATURALI
Corso di studi
BIODIVERSITA' ED EVOLUZIONE
Relatori
relatore Prof.ssa Borgognini Tarli, Silvana
relatore Dott. Donati, Giuseppe
relatore Dott. Donati, Giuseppe
Parole chiave
- degraded
- ecology
- Eulemur
- forest
- lemur
- madagascar
Data inizio appello
27/04/2012
Consultabilità
Completa
Riassunto
The red collared brown lemurs (Eulemur collaris) is the largest seed dispersals living in the humid littoral forests in South-eastern Madagascar. The critical ecological role of this species made it a fundamental study object in researches for habitat conservation.
We made a comparative study between groups of Eulemur collaris living in a well conserved littoral forest fragment (Saint Luce) and groups living in degraded and fragmented forest fragments (Mandena). This comparison allowed us to understand how red-collared brown lemurs live under ecological challenging condition and which strategy they use. This knowledge is essential to proper a well wild life management.
Our study confirms the great flexibility of E. collaris, already shown in previous researches. The species is capable to live in a degraded and fragmented habitat, such as Mandena, modifying its behaviour. Nutritional analysis showed that E. collaris were not under nutritional stress as heavily as supposed. It was able to adjust its feeding strategy as well to cope with the more degraded structure of Mandena. However, it made significant changes, mostly in group size and time budget. Mandena groups were significantly smaller and subordinated individuals were mobbed during lean period, while animal activity was characterized by energy saving during all the study period via high percentage of resting. E. collaris showed behavioral flexibility also under the social profile. Hierarchy and sexual dominance changed in response to ecological factors, being more rigid and female dominant when the environmental conditions were more challenging.
We also investigated the presence of heterothermy in this species but our results did not show evidences of this energy saving strategy via metabolic rate reduction in Eulemur collaris.
We made a comparative study between groups of Eulemur collaris living in a well conserved littoral forest fragment (Saint Luce) and groups living in degraded and fragmented forest fragments (Mandena). This comparison allowed us to understand how red-collared brown lemurs live under ecological challenging condition and which strategy they use. This knowledge is essential to proper a well wild life management.
Our study confirms the great flexibility of E. collaris, already shown in previous researches. The species is capable to live in a degraded and fragmented habitat, such as Mandena, modifying its behaviour. Nutritional analysis showed that E. collaris were not under nutritional stress as heavily as supposed. It was able to adjust its feeding strategy as well to cope with the more degraded structure of Mandena. However, it made significant changes, mostly in group size and time budget. Mandena groups were significantly smaller and subordinated individuals were mobbed during lean period, while animal activity was characterized by energy saving during all the study period via high percentage of resting. E. collaris showed behavioral flexibility also under the social profile. Hierarchy and sexual dominance changed in response to ecological factors, being more rigid and female dominant when the environmental conditions were more challenging.
We also investigated the presence of heterothermy in this species but our results did not show evidences of this energy saving strategy via metabolic rate reduction in Eulemur collaris.
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