Vasileios J. Kontsiotis

Key factors determining the seasonal population growth rate of European wild rabbits and their implications for management

Recently, the European rabbit (Oryctolagus cuniculus) has received contrasting considerations due to its multidimensional role in the Mediterranean ecosystems. Within this framework, knowledge of factors determining its population size may have important consequences for designing an effective management plan. In this paper, we quantified the combined influence of the major demographic and mechanistic factors on seasonal population fluctuation of European rabbits on Lemnos Island (Greece), during 2007–2009. We developed a hypothetical model taking into account direct (productivity, predation, hunting pressure, food shortage, habitat treatment) and indirect factors (soil moisture, adverse weather conditions) using structural equation modeling. We tested for their influence on the seasonal population growth rate (spgr) as determined by line transects to estimate rabbit abundance. The productivity induced higher pgr. Food shortage, which is affected by low soil moisture during the late summer and early autumn, is demonstrated to be the most important negative factor followed by the hunting pressure and predation. Demographic and mechanistic factors highlighted in this analysis could be used either for conservation or for controlling populations of the species.

Modeling the distribution of wild rabbits (Oryctolagus cuniculus) on a Mediterranean island

The European rabbit (Oryctolagus cuniculus) is a widely distributed mammal with an often contradictory ecological role, imposing the need for population management. Sound management requires an in-depth understanding of the complex species–habitat relationships. In this study, CART analysis was employed to identify the most important environmental and anthropogenic factors affecting the spatial distribution of wild rabbit on Lemnos Island, northeastern Aegean Sea in Greece. On Lemnos, this species is considered an agricultural pest due to its overabundance resulting from the long-term absence of viral diseases, limited predation pressure, and lack of effective management. The study was carried out during the summer of 2008 by surveying rabbit densities in 181 2xa0×xa02-km squares. Seven environmental and 14 anthropogenic variables, measured at two spatial scales, were used as explanatory variables. Soil hardness was the most influential variable, dividing the island into two distinct areas, namely the rabbit-poor areas with hard rocky soils and the rabbit-rich areas where soft soils prevail. In the former, the presence of a sharp relief can lead to complete absence of the species, while a combination of gentle relief, low altitudes, and low presence of arable land can lead to moderate rabbit density. In the latter, human-caused disturbance can reduce the number of rabbits, while a high density of ecotones and streams and a high presence of riparian vegetation can increase population densities to its highest levels observed. Our findings can formulate a scientific basis for the development of an effective management strategy for its population control.

Effects of attitudes and demography on public support for endangered species conservation

It is critical for managers to understand how attitudes and demography affect publics preferences for species protection for designing successful conservation projects. 1080 adults in Greece were asked to rate pictures of 12 endangered species on aesthetic and negativistic attitudes, and intention to support their conservation. Factor analysis identified a group of animals for which respondents indicated high levels of support for their conservation (red deer, loggerhead sea turtle, brown bear, common pheasant, European ground squirrel, glossy ibis) and a group of animals for which respondents indicated low levels of support (black vulture, great white shark, fire-bellied toad, western barbastelle, Cretan tube web spider, Milos viper). The species that received the highest support were also rated as the most attractive and safest, excluding the fearsome brown bear. Structural models revealed that aesthetic, moralistic and negativistic attitudes were the stronger predictors of support. Aesthetic and moralistic attitudes were positively, and negativistic attitudes negatively, correlated with support for conservation in both groups. Consumptive users scored lower in aesthetics and were less supportive of protection in the high support group, while nonconsumptive users showed the opposite trend. Respondents residing in urban areas deemed animals of high support more attractive and less fearsome and were more supportive of conservation than rural residents in both groups. Females of higher education viewed animals of low support as fearsome, however they supported their conservation. Our study identified popular species that can be used as flagship species to facilitate the implementation of conservation projects. The results of this study could also be used to design a communication and outreach campaign to raise awareness about the ecosystem value of less attractive species.

Body condition variation of wild rabbit population in the north-east Mediterranean island of Lemnos — Greece

Abstract. European wild rabbit (Oryctolagus cuniculus) is a widely distributed species with a multiple role in both environmental sustainability and local economy. In the current study we examine the body condition of the species in relation to habitat type, age, sex and seasonality on the island of Lemnos. Body condition was assessed based on a visual estimation of the amount of abdominal fat. A high intra-annual variation in the body condition of the species has been observed, which is further affected by sex and age. The species appears to conserve and maintain high levels of energy reserves for two main reasons. The first is to ensure a better reproductive success, as expressed by the relatively high amount of stored fat reserves at the onset of breeding season, and their depletion during it. The second is to ensure survival during periods where the shortage of food creates a rather hostile environment, as expressed by the increased level of reserves during summer and their dramatic decrease from late summer until autumn. The temporal fluctuation in energy reserves differs between male and female rabbits, reflecting their temporally different energy demands. Further, differences in body conditions were observed between juvenile and adult individuals, reflecting their different needs in terms of body growth and maintenance. Our results could offer important insights for the development of a time specific management plan and measures to ensure either the control of the population or its conservation.

The influence of habitat structure on the European brown hare Lepus europaeus food habits in mountainous areas of northern Greece

No abstract available

Public acceptance of management methods under different human–wildlife conflict scenarios

Wildlife management seeks to minimise public controversy for successful application of wildlife control methods. Human dimensions research in wildlife seeks a better understanding of public preferences for effective human-wildlife conflict resolution. In face to face interviews, 630 adults in Greece were asked to rate on a 5-point Likert-like scale their acceptance of 3 management methods, i.e., do nothing, non-lethal control, and lethal control, in the context of 5 human-wildlife conflict scenarios: 1) corvids damage crops; 2) starlings damage crops; 3) starlings foul urban structures; 4) coypus damage crops; and 5) coypus transfer disease. Univariate GLMs determined occupation, hunting membership and their interaction as the stronger predictors of public acceptance, generating 4 stakeholder groups: the general public, farmers, hunters, and farmers-hunters. Differences in acceptance and consensus among stakeholder groups were assessed using the Potential for Conflict Index2 (PCI2). All 4 stakeholder groups agreed that doing nothing was unacceptable and non-lethal control acceptable in all 5 scenarios, with generally high consensus within and between groups. The lethal control method was more controversial and became increasingly more acceptable as the severity of scenarios was increased and between non-native and native species. Lethal control was unacceptable for the general public in all scenarios. Farmers accepted lethal methods in the corvids and starlings scenarios, were neutral in the coypus damage crops scenario, whereas they accepted lethal control when coypus transfer disease. Hunters opinion was neutral in the corvids, starlings and coypus damage crops and starlings foul urban structures scenarios, but they accepted lethal methods in the coypus transfer disease scenario. Farmers-hunters considered lethal control acceptable in all 5 scenarios. Implications from this study could be used for designing a socio-ecological approach which incorporates wildlife management with public interests. The studied species have a wide distribution, therefore present findings might also prove useful elsewhere.

Trophic ecology of the European wild rabbit Oryctolagus cuniculus on the Mediterranean island of Lemnos, Greece

The European wild rabbit (Oryctolagus cuniculus) is a species with a wide distribution across the globe and a contradicting role in the ecological integrity of ecosystems and local economies. Despite the considerable amount of research that has been conducted on the trophic ecology of the species in continental environments, similar studies in insular environments are still fairly scarce. The article examines the trophic ecology of wild rabbit, using microhistological analysis to study its annual dietary composition in relation to the availability and quality of food sources, in two different habitats of a northeast Mediterranean island. A total of 112 species were found to participate, to a lower or greater degree, in the species diet across the year. The available food sources, as well as the identified food items, were classified in three feeding functional groups (FFGs), namely, grasses, forbs and parts of woody plants. Wild rabbit follows a diverse diet having adapted to the seasonal changes in the availability and quality of food sources. Forbs is the FFG which constitutes the main food source of the species, while grasses and parts of woody plants form occasionally an important component of its diet. The FFG of grasses is almost constantly preferred in both habitat types and plays a deterministic role in the trophic ecology of wild rabbit. During the critical dry season, where the availability of high quality food becomes limited, the species preferably consumes taxa that are generally less palatable and even toxic in its struggle for survival.

The two faces of Janus, or the dual mode of public attitudes towards snakes

Snakes are controversial animals, therefore a better understanding of public attitudes is critical for their effective protection and future survival. The attitudes towards snakes of 951 adults in Greece were investigated in personal interviews. Factor analysis revealed a dual mode of attitudes: respondents were highly intolerant of snakes, while they supported their conservation at the same time. Respondents had high knowledge about the behavior of snakes, medium knowledge of their biology and were strongly affected by folklore. Structural models revealed that tolerance was a positive mediator of conservation. Knowledge about snake behavior and biology was positively correlated with attitudes towards snakes. Moralistic and naturalistic attitudes were positively, and dominionistic attitudes negatively, correlated with snake tolerance and conservation attitudes. Younger, more educated people were more snake-tolerant than older, less educated people. Females were less snake-tolerant and more conservation-oriented than males. These findings increased the understanding of human attitudes towards snakes and helped identify factors critical for their conservation. As such they could be used to design environmental education programs incorporating both information-based and experiential activities that will improve attitudes, behaviors and, eventually, the chances for the survival of these uncharismatic animals.

Impact of European wild rabbits foraging in different habitat and vegetation types in an insular environment

Abstract European wild rabbits (Oryctolagus cuniculus) are prolific herbivores, affecting natural and agricultural ecosystems. We installed 10 experimental units, each consisting of two fenced plots, one excluding all herbivores and one allowing rabbit access only, to estimate the impact of rabbit grazing in three vegetation types occurring in two dominant habitat types on Lemnos Island, Greece. Plant productivity was significantly higher in barley crops than on both fallow land and Mediterranean scrublands. Rabbit grazing caused significant reduction of productivity in barley crops and Mediterranean scrublands, but not on fallow land. Selective feeding and seasonal food availability may have shaped patterns of rabbit impact.

Effects of environmental and intrinsic factors on the reproduction of insular European wild rabbits (Oryctolagus cuniculus cuniculus Linnaeus 1758)

Abstract European wild rabbits (Oryctolagus cuniculus cuniculus) have been recently recognized as serious crop pests on Lemnos Island, Greece. With an aim to understand the population dynamics, rabbit reproduction was studied in relation to environmental and intrinsic factors, by a postmortem examination of 273 adults (162 males, 111 females), collected from February 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 explanatory 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. proportion pregnant). At a higher maximum temperature, pregnancy 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 identified temperature and habitat quality as prime drivers of reproduction, and ultimately population dynamics. Such information could prove useful for successful rabbit management on Lemnos and other similar areas.