An Evaluation of the Use of the Western Harvest Mouse as an Indicator Species in Indiana

Climatic and anthropogenic influences have alteredwildlife habitats throughout the world. Habitatre-establishment and management are vital for thepersistence of Indiana prairie biomes. An easy methodfor assessing the health of an ecosystem is detection ofendemic or “indicator” species of an area. An example ofa prairie indicator species in the western United States isReithrodontomys megalotis, the Western Harvest Mouse(WHM), as it is a grassland specialist. Its small statureallows it to gather seeds from the tops of prairie grassstems. WHM have recently been discovered in Indiana andare a species of special concern. However, very few studieshave investigated their ecology and behavior. The objectiveof this research is to determine whether WHM can be usedas an indicator species of prairie health in Indiana. Foursites at the Purdue Wildlife Area where WHM had beenpreviously documented were live-trapped in the spring andfall for three years with intermittent prescribed burns andbrush-hogging events to favor tallgrass vegetation growth.Vegetative surveys were conducted both at locations whereWHM were captured and at an equal number of random,non-WHM capture locations. Logistic regression analysisdid not detect any significant correlation between WHMand specific microhabitat characteristics. However, WHMpersisted in all sites that are mid–late successional prairies(areas with dense ground debris in addition to tallgrasses)but were absent in sites encroached by woody vegetation.This may support their use as an indicator species of prairiehealth in Indiana.