Mammalia 2019; 83(2): 134–143 Vasileios J. Kontsiotis*, Panteleimon Xofis, Vasilios Liordos and Dimitrios E. Bakaloudis Effects of environmental and intrinsic factors on the reproduction of insular European wild rabbits (Oryctolagus cuniculus cuniculus Linnaeus 1758) https://doi.org/10.1515/mammalia-2017-0136 Received October 11, 2017; accepted March 29, 2018; previously published online June 15, 2018 Abstract: European wild rabbits (Oryctolagus cunicu- lus cuniculus) have been recently recognized as seri- ous crop pests on Lemnos Island, Greece. With an aim to understand the population dynamics, rabbit repro- duction was studied in relation to environmental and intrinsic factors, by a postmortem examination of 273 adults (162 males, 111 females), collected from Febru- ary 2007 to January 2008. Reproductive activity peaked in the spring and was higher in agricultural than in phryganic habitats for females [pregnant: agricultural 74.5%, phryganic 54.0%, p = 0.041; average number of implanted embryos: agricultural 5.56 ± 0.21 standard error (SE), phryganic 4.07 ± 0.21 SE, p = 0.0002], but not for males (fertile: agricultural 38.8%, phryganic 31.2%, p = 0.308). Classification tree models included explana- tory variables with monthly time lags to detect important effects. The male reproductive status (i.e. proportion fertile) was favored by a low maximum temperature in the sampling month (<21.5°C), whereas under a higher maximum temperature male fertility was favored by a high vegetation quality (>14.2% crude protein, CP), good body condition and low mean temperature (<20.5°C). A low maximum temperature at conception (<20.0°C; 1 month time lag) favored pregnancy status (i.e. propor- tion pregnant). At a higher maximum temperature, preg- nancy was favored by a high vegetation cover (>86.8%) at conception. Vegetation quality higher than 10.9% CP resulted in a medium to high number of implanted embryos (2 months time lag), further determined by a high vegetation cover (>90.8%; 2 months time lag) and a low population density (<1.9 ind · ha −1 ). The results iden- tified temperature and habitat quality as prime drivers of reproduction, and ultimately population dynamics. Such information could prove useful for successful rab- bit management on Lemnos and other similar areas. Keywords: breeding season; litter size; male fertility; preg- nancy status; reproductive parameters. Introduction The European wild rabbit (Oryctolagus cuniculus Linnaeus 1758), hereafter referred to as the rabbit, has been classified as near threatened in its natural range by the International Union for Conservation of Nature (IUCN) (Smith and Boyer 2008). Outside its natural range it is a successful colonizer (Flux and Fullagar 1992), cur- rently having an almost global distribution, mostly due to human-assisted colonization (Flux 1994). The rabbit plays a multidimensional ecological and socioeconomic role, both positive (e.g. seed disperser, valued game; Delibes-Mateos et al. 2008, 2009, Ferreira et al. 2014) and negative (e.g. agricultural pest, wildlife, livestock competitor; Thompson and King 1994, Williams et al. 1995, Lees and Bell 2008, Norbury and Jones 2015). The rabbit’s negative impact is more severe on colonized islands, because the local biota has evolved in the absence of prolific herbivores (Veitch and Clout 2002, Courchamp et al. 2003). These negative impacts have led to its inclusion in the IUCN list of the 100 worst invasive species (Global Invasive Species Database 2016). The rabbit (subspecies Oryctolagus cuniculus cunicu- lus) was introduced as game to the island of Lemnos, Greece, several centuries ago, probably by the Phoeni- cians and/or the Romans (Gibb 1990, Flux and Fullagar 1992, Williams et al. 1995). However, its increased popula- tion over the last two decades turned it into a major agri- cultural and environmental pest, with negative effects on local economy and ecosystem integrity (Kontsiotis et al. 2018). After continuous allegations by local farmers, the Hellenic Organization of Agricultural Insurances (ELGA) *Corresponding author: Vasileios J. Kontsiotis, Department of Forestry and Natural Environment Management, Eastern Macedonia and Thrace Institute of Technology, P.O. Box 172, 66100 Drama, Greece, e-mail: kontsiotisv@yahoo.gr Panteleimon Xofis and Vasilios Liordos: Department of Forestry and Natural Environment Management, Eastern Macedonia and Thrace Institute of Technology, P.O. Box 172, 66100 Drama, Greece Dimitrios E. Bakaloudis: Department of Range Sciences, Wildlife and Freshwater Fisheries, School of Forestry and Natural Environment, Aristotle University of Thessaloniki, P.O. Box 241, 541 24 Thessaloniki, Greece Authenticated | kontsiotisv@yahoo.gr author's copy Download Date | 3/13/19 8:27 PM