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European hare in Mid-Ulster

Tissue samples were opportunistically collected from 33 hares involved in road traffic accidents in Mid-Ulster from 2003 to 2008. Molecular analysis of a partial region of the transferrin nuclear gene and a segment of mitochondrial DNA was used to establish the genetic identity of each individual.
 
Genetic profiling unambiguously assigned 17/33 samples (c. 51%) as Irish hares, 6/33 samples (c. 18%) as European hares and 6/33 samples (c. 18%) as interspecific hybrids. Four individuals (c. 12%) could not be reliably identified.
 
Bidirectional hybridisation of both species has been confirmed. Five interspecific hybrids were the result of male European hares (♂) mating with female Irish hares (♀) whilst one hybrid appeared to be the result of a reciprocal mating of a female European hare (♀) with a male Irish hare (♂).
 
If European hares were introduced to Northern Ireland recently, it follows that hybridization represents a significant threat to sympatric Irish hares. However, if extant European hare populations are descendant from individuals introduced during the late 1800s, their geographically restricted range indicates that hybrids have a reduced reproductive fitness. Thus, despite hybridization, both sympatric species may be able to maintain their own genetic integrity. There are no data by which to evaluate each hypothesis; consequently, more work is required to fully establish the threat that interspecific hybridisation poses to the native Irish hare.
 
The UK and Ireland have international obligations under the Convention on Biological Diversity (1992), the Bern Convention (1979) and the European Habitats Directive (EEC 43/92) to address invasive species issues. Immediate action is often the only opportunity for cost-effective eradication.
 
We made five recommendations for future research and action:

1. Establish a European hare population monitoring programme to determine temporal trends and the short-term trajectory of the population.
    
2. Conduct further genetic work involving systematic sampling to establish the full extent of interspecific hybridisation including the prevalence of backcrossing and introgression.
    
3. Obtain additional European hare samples from Great Britain to establish the origin(s) of the species in Ireland and determine the likely time-frame of introduction.
    
4. Consider establishing an experimental approach to assess both individual and population fitness consequences of bidirectionl hybridisation under captive conditions.
    
5. Develop a ‘European hare eradication strategy’ including an evaluation of the efficacy of management practises and the most effective means by which they can be deployed without compromising the native Irish hare.

You can download the final report here:
 
Hughes, M., Reid, N., Montgomery, W.I. & Prodöhl, P. A. (2009) Verification of hybridisation between introduced European and native Irish hares. Report prepared by the Natural Heritage Research Partnership, Quercus for the Northern Ireland Environment Agency, Northern Ireland, UK.