Current Zoology 61 (4): 781–791, 2015 Received Mar. 10, 2015; accepted Apr. 22, 2015.  Corresponding author. E-mail: belias@volny.cz © 2015 Current Zoology Why not to avoid the smell of danger? Unexpected behavior of the Cypriot mouse surviving on the island invaded by black rats Daniel FRYNTA 1,2 , Margaréta BALAĎOVÁ 1 , Barbora ELIÁŠOVÁ 1,2,* , Silvie LIŠKOVÁ 2 , Eva LANDOVÁ 1,2 1 Department of Zoology, Faculty of Science, Charles University, Vinicna 7 128 44 Prague 2, Czech Republic 2 National Institut of Mental Health, Topolova 748, 250 67 Klecany, Czech Republic Abstract Mus cypriacus is a recently discovered endemic species that evolved about half a million years ago on the Cyprus Is- land in an absence of most mammalian predators and competitors. As on other Mediterranean islands, the faunal composition was dramatically changed by the invasion of commensal and domestic species following Holocene colonization by humans. We exa- mined the behavioral responses of the Cypriot mouse to the odors of these new competitors (black and Norway rat, house mouse and spiny-mouse) and predator (domestic cat) as well as controls (Herb-field mouse, guinea pig). We compared them with those of mainland population of house mouse from Syria with different coexistence history. Surprisingly, the Cypriot mouse failed to avoid the odor of its current main competitor, the black rat. Moreover, the response patterns of both the Cypriot and Syrian house mice to the examined odor sources appeared fairly comparable. There was a clear tendency to prefer odors of other murids over unscented sawdust as well as to avoid the odor of a domestic cat. In conclusion, neither the long-term isolation from predators nor the recent strong competition with black rats affected mice competitory and antipredatory responses fundamentally [Current Zoo- logy 61 (4): 781–791, 2015]. Keywords Competition, Cyprus, Mus cypriacus, Odor preference, Rattus rattus Insular species often evolved in the absence of any competitors or predators, and thus, their competitive or antipredatory abilities are usually deficient or low (re- viewed in Courchamp et al., 2003). Many introduced species contribute to the reduction of native island fauna (e.g., interspecific competition for nest sites: Matsui et al., 2010; exploitative competition for food: Gurnell et al., 2004). As for predatory pressure, a common exam- ple is the Galápagos marine iguana Amblyrhynchus cristatus endangered by introduced dogs (Rödl et al., 2007) or endemic seabirds vulnerable to alien predators (rats, minks, stoats), especially during the nesting sea- son (Maloney and McLean, 1995; Craik, 1997; Penloup et al., 1997). Over 80% of the world’s major island groups are al- ready colonized by rats of the genus Rattus (Atkinson 1985; Harris 2009) and these are able to exploit a wide range of habitats and resources (Ruffino et al., 2011). Not only they are strong competitors of indigenous spe- cies (cf. Harper and Cabrera, 2010), they are also known to kill mice (Karli, 1956, Bridgman et al., 2013) and other small animals (seabirds in colonies: Stapp, 2002; hatchlings of sea turtles: Caut et al., 2008). In fact, rats are the largest contributor to seabird (Towns et al., 2006; Jones et al., 2008) and small mammal extinctions on islands (Harris, 2009). For these reasons, the black rat Rattus rattus is on a list of the top hundred world’s worst invasive alien species (Lowe et al., 2000). The only small endemic mammals that survived up to the present time are: the shrew Crocidura zimmermanni on Crete (Vogel et al., 1986; Dubey et al., 2007), C. sicula on Sicily (Vogel et al., 1990), C. cypria (Spitzen- berger, 1978; Kryštufek and Vohralík, 2001) and the mouse Mus cypriacus on Cyprus (Bonhomme et al., 2004; Cucchi et al., 2006; Macholán et al., 2007). It is non-commensal species living in abandoned vineyard terraces, grassy fields, bushes or forested riverine areas (Cucchi et al., 2006). The common ancestor of M. cy- priacus and its sister taxon, M. macedonicus (Macholán et al., 2007) arrived on Cyprus probably during the Middle Pleistocene (Cucchi et al., 2006). There were no other rodents on the island a half million years ago Downloaded from https://academic.oup.com/cz/article-abstract/61/4/781/1803207 by guest on 08 June 2020