Dismembered frogs and confused starlings: all in a day’s work for the Garden Wildlife Health Project Team!

Reports of several unexplained amphibian mass mortalities, followed by the death of more than 50 starlings on a busy stretch of road; these are typical of a day’s events for Garden Wildlife Health (GWH), a project that aims to safeguard the health of British wildlife by conducting research into the causes and trends of diseases in a variety of species and investigating their impacts on the affected populations. Crucial to its success is the participation of the general public, who send in reports of sick and dead wildlife from gardens across Great Britain using our project website, www.gardenwildlifehealth.org.

GWH is a collaborative project between the Zoological Society of London, the British Trust for Ornithology, Froglife and the Royal Society for the Protection of Birds. ZSL takes the lead in day to day management with a team formed of Prof. Andrew Cunningham, Dr. Becki Lawson, Tim Hopkins, Shinto John, Gabriela Peniche and myself. With our origins in the Frog Mortality Project and the Garden Bird Health Initiative, we have spread our wings and expanded our remit from garden birds and amphibians to include hedgehogs and reptiles. In the last 12 months, we received more than 1400 reports of disease and examined 270 carcasses to post-mortem. Andrew and Becki oversee the project, publish reports and secure funding, while Tim and I respond to incident reports and perform post-mortem examinations. Shinto and Gabriela process samples and develop tests to detect and identify potential disease threats.

GWH has been responsible for the detection of several disease threats of potential conservation significance to our native wildlife species, including epidemic mortality in greenfinches caused by the parasite Trichomonas gallinae, and the emergence of a new and severe form of avian pox in great tits. From every wild animal that is examined, samples are archived into one of the largest wildlife tissue banks in the world which provides an important resource for future investigations. Currently, we are screening all our amphibian samples as part of a horizon scanning project for the new chytrid fungus threat, Batrachochytrium salamandrivorans. Not content with current diagnostic techniques, we are also constantly developing new tests such as a novel PCR test to detect Suttonella ornithocola, a bacterium that can cause respiratory disease in tit species and which is notoriously difficult to culture.

Although our focus has been on infectious disease, we also investigate non-infectious causes of ill-health. For example, in April we received a report from Scotland where many common frogs had been found with their hind limbs removed but with the attached skin inverted. This required some detective work, but we eventually concluded that otter predation was the cause of this ghastly spectacle. Otters have a predilection for the hind legs of frogs and, to avoid toxins in the amphibian skin, they painstakingly skinned the frog limbs!

Another mysterious report was the death of more than 50 starlings on a busy stretch of road in the Greater Manchester area. Evidence of blunt trauma was found on post-mortem examination and no signs of infectious disease were detected. Could it be that all 50 birds were involved in a road traffic collision? Although rare, there have been other reports of starling incidents where flocks of birds have been killed in road traffic incidents. Suggested reasons for the tragic event have included roost proximity to a major road, navigation error, predator evasion and/or distraction by local factors such as the light from traffic. Something to think about when you next see a flock of starlings overhead!

While our main role is to evaluate the impact of infectious and non-infectious disease on wildlife populations, we also conduct research on diseases of potential significance to public, livestock and companion animal health. For example, our work on salmonellosis has found clear evidence that salmonella can be passed from garden birds to humans in Britain. Also, through the project we have discovered that chlamydiosis, another disease that can infect humans, is more common in wild birds in Britain than had been previously considered. The GWH also provides best practice guidance on how to maximise the welfare of wildlife while minimising disease and other risks to both wildlife and people.

For more information on our work, see our website: www.gardenwildlifehealth.org

Lydia Franklinos

Wildlife Veterinarian/Postgraduate Research Assistant

Garden Wildlife Health (GWH)