Health Surveillance for the Species Recovery Programme
Native species translocations (reintroductions and re-stocking) present disease and welfare risks for the animals being translocated and other native species.
We undertake to minimize these risks through disease risk analysis prior to translocation, disease risk reduction if a translocation proceeds and post-release health and welfare surveillance to monitor the effect of translocation on translocated and sympatric species at the reintroduction site.
For the past 17 years, ZSL has carried out health surveillance for English Nature’s Species Recovery Programme (SRP), including projects on the field cricket Gryllus campestris , barberry carpet moth Pareulype berberata, pool frog Rana lessonae, sand lizard Lacerta agilis, cirl bunting Emberiza cirlus, corncrake Crex crex, red kite Milvus milvus , common dormouse Muscardinus avellanarius and red squirrel Sciurus vulgaris.
We also carry out disease monitoring on populations of declining native species, for example the remnant red squirrel populations in the north of England.
Red Squirrels
Disease monitoring of red squirrels after reintroduction highlighted the severe effects of squirrel poxvirus disease, in areas where grey squirrels are present, to the red squirrel population.
Field Crickets
Every population of field crickets reintroduced in England receives a disease risk analysis and screening, and we identified and eliminated an alien parasite, a eugregarine, from some of these populations. Find out more about Field cricket conservation .
Pool Frog
The pool frog became extinct in the UK during the 1990s but a project has commenced in which pool frogs have been reintroduced from Sweden, and we may once again see these ‘marsh nightingales’ inhabiting Norfolk.
The disease risk analysis screened for the two most dangerous known pathogens, chytrid fungus and ranavirus, as well as protozoa, helminths and bacteria, and established the prevalence of these parasites both within the pool frog populations and in native amphibians.
Post-release health surveillance is being carried out on pool frogs to monitor the effect of this translocation on native amphibians, such as smooth newts and common frogs, and on the pool frogs themselves.
Corncrakes
Corncrakes receive two health examinations during rearing to ensure they are at peak health prior to reintroduction into the Nene Washes, nr Peterborough. Find out more about Corncrake conservation .
Cirl Bunting
The cirl bunting population has decreased dramatically over the past 100 years, and by 1989 the population was estimated at a mere 118 pairs, with a subsequent modest recovery.
In collaboration with Natural England, and the RSPB, ZSL carried out a disease risk analysis and identified two coccidial parasites of potential significance to the health of these birds, Isospora normanlevinei and Haemoptroteus coatneyi.
Intensive disease risk management measures are currently been employed to reduce the effects of these parasites on the reintroduced birds.
Red Kites
Since 1989, ZSL has been involved with the reintroduction of red kites to the wild. Ongoing health surveillance on the reintroduced populations has identified the danger posed by poisoning through misuse or abuse of agricultural chemicals, and lead, from shot prey, to their survival.
Dormice
Health surveillance of common dormice identified a potentially alien cestode (tapeworm) parasite of the genus Rodentolepis, and developed essential protocols for its elimination prior to the release of dormice to the wild.


