Joshua Seth Eaton’s research while affiliated with University of Wisconsin–Madison and other places

With over 2200 extant species, rodents (order Rodentia) represent the largest mammalian order and comprise 42% of global mammalian biodiversity (Donnelly et al. 2015). Rodents represent a diversity of morphological adaptations associated with their varied terrestrial and aquatic habitats, distributed throughout all continents except Antarctica. One common feature to all Rodentia is a powerful anatomical apparatus for chewing and gnawing, characterized by prominent rostral dentition and a large and often complex masseter muscle. The differing morphological characteristics and adaptations of the zygomasseteric apparatus are used to divide the Rodentia into five suborders including the Anomaluromorpha, Castorimorpha, Hystricomorpha, Sciuromorpha, and Myomorpha (Wilson and Reeder 2005).

Members of the order Lagomorpha comprise two families, the Leporidae (domestic and wild rabbits and hares) and the Ochotonidae (pikas). There are over 60 extant species of rabbits and hares. In the wild, rabbits and hares are herbivorous, non-hibernatory, and invariably terrestrial but are found in a diversity of natural habitats on multiple continents, ranging from the subtropics to open desert to boreal forests and arctic tundra (Nowak and Walker 1999) (Table 42.1). It is noteworthy, however, that many populations of Leporidae are not native, instead introduced to their respective regions or continents by humans (Nowak and Walker 1999). The European rabbit (Oryctolagus cuniculus), for example, is not native to Australia but was introduced to the continent in the nineteenth century and has become an invasive species, reported to have a negative impact on native ecosystems (Barrio et al. 2010; Fenner 2010). The Leporidae are preyed upon by many terrestrial and avian carnivorous species, and follow predominantly crepuscular and/or nocturnal activity patterns (Delaney et al. 2018). Despite similarities in habitat and activity, social structure differs between rabbits and hares, with rabbits tending to form colonies and hares being predominantly solitary animals (Flux and Angermann 1990). At birth, rabbit kits are blind and lack fur whereas leverets (baby hares) are born with a full fur-coat and are precocial (Delaney et al. 2018).