Turlure, Camille
[UCL]
(eng)
The significance of the resource-based definition for a butterfly's habitat has been particularly well discussed in the ecological literature. However, most studies mainly focus on one or a few life stages (with a strong bias to adult ecology). The importance of often neglected resources (e.g. adult roosting and mate-locating sites, thermal conditions needed for caterpillars) was particularly stressed, as well as the often inappropriate distinction between habitat and landscape matrix. Nevertheless, the resource-based definition has rarely been tested while considering in detail the whole life cycle of an organism.
Therefore, using five butterfly species of the peat bog guild, the main objectives of this thesis were: 1) To define what makes up the habitat for each species, based on requirements of each life stage, and assess whether the resource-based definition is more appropriate than more widely used definitions based on vegetation associations or host plant patches, 2) To compare definitions of the habitat drawn for the species and determine whether the habitat is species-specific, and 3) More conceptually, even if the habitat is a complex issue, we finally generated a general framework to recognise a species habitat. To reach these objectives, we introduced a two step approach based on observations of habitat-use in the field (i.e., patterns) and experimental tests of organism responses under controlled conditions (i.e., processes).
Definitions of the habitat based on host plant abundance (or patches) or vegetation types were mostly weak. Such definitions may be only suitable for species for which all resources are aggregated within or near host plant patches or in a particular vegetation type. A complete, functional definition of the habitat from a butterfly's point of view considers several resources and hence incorporate three major parameters: 1) resource composition (i.e. the list of resources required by the organism), 2) resource configuration (i.e. both the grain of each resource and the organization of all the resources) and 3) resource availability. The intersection of these three parameters represents the functional habitat of a given population or a given species within a landscape. Variations in these parameters are likely to influence individual behaviour, individual fitness, demographic response of the population, and the evolution of resource or habitat exploitation strategies.


Bibliographic reference |
Turlure, Camille. Habitat from a butterfly's point of view : how specialist butterflies map onto ecological resources. Prom. : van Dyck, Hans ; Schtickzelle, Nicolas |
Permanent URL |
http://hdl.handle.net/2078.1/22479 |