Informations et ressources scientifiques
sur le développement des zones arides et semi-arides

Accueil du site → Doctorat → Australie → 2019 → Response of Australian Boobooks (Ninox boobook) to threatening processes across urban, agricultural, and woodland ecosystems

Edith Cowan University (2019)

Response of Australian Boobooks (Ninox boobook) to threatening processes across urban, agricultural, and woodland ecosystems

Lohr Michael Thomas

Titre : Response of Australian Boobooks (Ninox boobook) to threatening processes across urban, agricultural, and woodland ecosystems

Auteur : Lohr Michael Thomas

Université de soutenance : Edith Cowan University

Grade : Doctor of Philosophy (PhD) 2019

Résumé partiel
The effects of habitat fragmentation on native wildlife can vary depending on the type of land use occurring in the matrix between remaining habitat fragments. I used Australian boobooks (Ninox boobook) in Western Australia to investigate interactions between matrix type and four different potential threatening processes : secondary poisoning by anticoagulant rodenticides (ARs) ; limitation of juvenile dispersal and impacts on spatial genetic structure ; breeding site availability ; and infection by the parasite Toxoplasma gondii.

I also conducted a literature review on the use and regulation of ARs in Australia and published accounts of non-target impacts in order to contextualise exposure patterns observed in boobooks. The review revealed records of confirmed or suspected poisoning across 37 vertebrate species in Australia. World literature relating to AR exposure in reptiles suggests that they may be less susceptible to AR poisoning than birds and mammals. This relative resistance may create unevaluated risks for wildlife and humans in Australia where reptiles are more abundant than in cooler regions where AR exposure has been studied in greater depth.

I analysed AR residues in boobook livers across multiple habitat types. Second generation anticoagulant rodenticides were detected in 72.6% of individuals sampled. Total AR concentration correlated positively with the proportion of urban land use within an area approximately the size of a boobook’s home range centred on the point where the sample was collected. ARs originating in urban habitat probably pose a substantial threat to boobooks and other predatory wildlife species.

No spatial genetic structure was evident in boobooks across habitat types. I observed one individual dispersing at least 26km from its natal home range across urban habitat. The apparent permeability of anthropogenically altered landscapes probably explains the lack of spatial genetic structure and is likely related to the observed ability of boobooks to use resources in both urban and agricultural matrices.

Présentation

Page publiée le 19 janvier 2021