Australia has identified the Southern Boobook as a species that has suffered
range-wide decreases in numbers across Australia since 1999 and concluded that
“further investigation is needed to understand the factors that are driving
this consistent decline across regions.”
Mike Lohr will be studying the impacts of habitat fragmentation on
Southern Booboooks in Perth and surrounding areas. He will be looking at how different types of
habitat fragmentation (urban and agricultural) impact Southern Boobooks. Understanding the threats facing boobooks and
where these threats are most severe will help explain the ongoing decline in
boobook populations and inform plans to reverse it.
Threats being studied
- Inbreeding – The isolation of Boobook’s woodland habitats by urban development and agriculture, may be making it difficult for birds to find new territories. This can lead to inbreeding, which can decrease survival and fertility. Mike plans to examine the genetics of urban, agricultural, and woodland populations to see if inbreeding is a problem for this species.
- Nest Hollow Loss – All boobooks need tree hollows for nesting and these may be greatly limiting. Small remnant woodlands lose trees with hollows faster than larger woodlands. Introduced bird species like Long-billed Corellas and overabundant species like Galahs benefit from human activities and are growing in numbers in urban and agricultural areas. They may be competing with boobooks and other hollow-nesting birds for scarce nesting sites. Mike will test whether providing artificial boobook nest boxes increases their numbers in areas where they are not present and examine what other species use these boxes and might be competing with boobooks.
- Anticoagulant Rodenticides (Rat Poison) – Some types of rat poison that use blood thinners to kill rodents, can travel up the food chain when poisoned rodents are eaten by predators. Stronger “second generation” anticoagulant rodenticides have been shown to affect predatory birds in North America and Europe. A number of countries have passed stricter laws on these substances, as a result. Mike plans to investigate whether traces of these substances are present in boobooks and whether the type of habitat they are using affects the amount and type of rat poison they are exposed to.
- Toxoplasmosis – Toxoplasmosis is a disease that affects both humans and wildlife. It is caused by the microorganism Toxoplasma gondii and is primarily spread by feral cats. Toxoplasmosis infection changes the brain chemistry of its hosts and can cause slight behavioural changes in both humans and animals. In humans it has been linked to higher risks of mental illnesses, risky behaviours, slowed reaction time, and car accidents. Mike wants to find out how common this infection is in boobooks, whether it may increase their risk of getting hit by cars, and whether it is more common in boobooks living in habitats with more free-roaming cats.
School of Science
Stuart Leslie Grant
Trustees Limited Holsworth Wildlife Research Endowment
Dr. Allan Burbidge (WA Department of Parks and