Universidade de Lisboa Repositório da Universidade de Lisboa

Repositório da Universidade de Lisboa >
Faculdade de Ciências (FC) >
FC - Dissertações de Mestrado >

Please use this identifier to cite or link to this item: http://hdl.handle.net/10451/1817

Title: Effects of seed availability on eurasian red squirrel (Sciurus vulgaris):life-history and demographic parameters in two pine forests in the italian Alps
Authors: Rodrigues, Diana Clamote
Advisor: Wauters, Lucas A.
Mathias, Maria da Luz, 1952-
Keywords: Mamíferos
Esquilo
Teses de mestrado
Issue Date: 2008
Abstract: Resumo alargado em português disponível no documento
In North Italy, the Eurasian red squirrel (Sciurus vulgaris) is threatened by the expansion of the introduced, invasive North-American grey squirrel (Sciurus carolinensis). Alpine conifer forests might constitute a stronghold for the long-term persistence of red squirrel populations in North Italy and adjacent countries. In resource limited systems, with a high degree of temporal variation in habitat quality, as Alpine conifer forests, the distribution and defensibility of critical resources are the main factors affecting life-history and demographic parameters of squirrels, which are still poorly understood in these more or less isolated and extreme habitats. In the present study, variation in tree-seed availability, red squirrels population densities, body size and mass and spacing patterns were monitored over different seasons in 2006 and 2007, to explore how differences in food availability between two alpine pine forests, Bormio (BOR) and Cancano (CAN), affected the behaviour and body condition of individual squirrels and the population densities, assuming that CAN was a marginal habitat contrary to BOR which was not one. Only in 2007, food availability was significantly different in the study sites, with seed-crop size being three times bigger at BOR than CAN. Red squirrels used larger home ranges and core areas and had a higher core area overlap at CAN than BOR, as predicted due to the need to meet daily energy-requirements. However, the expected increase in female-female core area overlap in CAN was not significant. Annual squirrel densities (BOR, 0.13 and 0.20 squirrels ha-1; CAN, 0.10 and 0.18 squirrels ha-1) and proportion of reproducing females were similar in both study sites and so was body mass, in contradiction with predictions that assumed lower density and body mass values for Cancano. These results suggest that there is no marked difference in habitat-quality between CAN and BOR and that the latter 'behaves' as a marginal habitat in years with poor pine-crops but as a medium-quality habitat in years of good pine-crops. Despite the logistic difficulties, future research should comprise long-term monitoring in both study sites and the comparison of lifehistory and demographic parameters from these populations with populations in other types of alpine forests, characterised by different temporal patterns in tree-seed availability and abundance.
Description: Tese de mestrado em Ecologia e Gestão Ambiental, apresentada à Universidade de Lisboa, através da Faculdade de Ciências, 2008
URI: http://catalogo.ul.pt/F/?func=item-global&doc_library=ULB01&type=03&doc_number=000545118
http://hdl.handle.net/10451/1817
Appears in Collections:FC - Dissertações de Mestrado

Files in This Item:

File Description SizeFormat
22583_ulfc080194_tm.pdf3.44 MBAdobe PDFView/Open
Statistics
FacebookTwitterDeliciousLinkedInDiggGoogle BookmarksMySpaceOrkut
Formato BibTex mendeley Endnote Logotipo do DeGóis 

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.

 

  © Universidade de Lisboa / SIBUL
Alameda da Universidade | Cidade Universitária | 1649-004 Lisboa | Portugal
Tel. +351 217967624 | Fax +351 217933624 | repositorio@reitoria.ul.pt - Feedback - Statistics
DeGóis
  Estamos no RCAAP Governo Português separator Ministério da Educação e Ciência   Fundação para a Ciência e a Tecnologia

Financiado por:

POS_C UE