Investigating the effects of meningeal worm on elk calf survival and estimating the elk population in eastern Kentucky

The meningeal worm (Parelaphostrongylus tenuis) is a parasitic nematode that occurs throughout the Southeast, except for the Atlantic and Gulf coastal plains. As the definitive host for this parasite, the white-tailed deer (Odocoileus virginian us) can support the completion of the meningeal worm life cycle without being physically harmed. However, if elk (Cervus elaphus) ingest meningeal worm larvae, the parasite can cause fatal neurological disease. Preliminary findings have suggested that elk calves are more susceptible to disease and mortality caused by meningeal worm in eastern Kentucky (Larkin et al. 2003, Alexy 2004) and that additional research is necessary. Because of the growing ecological and economic importance of elk in this area, it is imperative to understand the effects that this parasite can have on the population. Throughout Kentucky's restoration zone 86% of white-tailed deer are infected with adult P. tenuis before 2.5 years old (Alexy 2004). In an established herd, mortality involves mostly immunologically naIve recruits into the population (Lankester 200 I). A recent study indicated that 80% of Kentucky-born elk that succumbed to infection died as calves or yearlings (Alexy 2004). Meningeal worm-induced adult mortality in Kentuckyborn elk may not be as prevalent if they developed immunity as calves upon initial exposure to subsequent infection (Davidson et al. 1985, Samuel et al. 1992). Elk born in Kentucky likely encounter the parasite at a young age and, depending on the number of infective larvae ingested may either acquire immunity or develop the disease. Furthermore, previous research investigating the temporal and spatial distribution of infected gastropods, the intermediate host of the parasite, indicated that infection in elk may vary based on habitat utilization and location (Alexy 2004). Additionally, it is vital to the management of elk in eastern Kentucky that we are confident in the population model that was created for this area. This population model is used to set the target population and harvest strategies for elk throughout the restoration zone. Therefore, because ofthe importance ofa well-founded population estimate, we will attempt to use the radio-collared animals in this study to test several population estimate techniques and test the population model provided by KDFWR.