Combining ranger records and biogeographical models to identify the current and potential distribution of an expanding mesocarnivore in southern Europe

Human-wildlife conflicts (HWC) are increasing and are potentially harmful to both people and wildlife. Understanding the current and potential distribution of wildlife species involved in HWC, such as carnivores, is essential for implementing management and conservation measures for such species. In this study, we assessed both the current distribution and potential distribution (forecast) of the Egyptian mongoose (Herpestes ichneumon) in the central part of the Iberian Peninsula. We acquired data concerning mongoose occurrences through an online questionnaire sent to environmental rangers. We used the municipality level as the sampling unit because all municipalities within the study area were covered at least by one ranger. Using the information provided by rangers (i.e. occurrences in their municipalities), we constructed environmental favourability distribution models to assess current and potential mongoose distribution through current distribution models (CDM) and ecological models (EM), respectively. >300 rangers participated in the survey and mongooses were reported in a total of 181 of 921 municipalities studied. The CDM model showed a current distribution mainly concentrated on the western part of the study area, where intermediate-high favourability values predominated. The EM model revealed a wider potential distribution, including the south-east part of the study area, which was also characterised by intermediate-high favourability values. Our predictions were verified using independent data, including confirmation of mongoose reproduction by rangers, reports by other experts, and field sampling in some areas. Our innovative approach based on an online survey to rangers coupled with environmental favourability models is shown to be a useful methodology for assessing the current distribution of cryptic but expanding wildlife species, while also enabling estimations of future steps in their expansion. The approach proposed may help policy decision-makers seeking to ensure the conservation of expanding wildlife species, for example, by designing awareness campaigns in areas where the target species is expected to arrive.

Multi-scale habitat associations of the black-footed rock-wallaby in north-western South Australia

Context Research on species’ habitat associations is strengthened if it combines coarse-grained landscape data with finer-scale parameters. However, due to the effort required to measure fine-scale parameters, studies on threatened species that unite these two scales remain relatively rare. Aim This study aimed to undertake a multi-scale analysis of the habitat association of the threatened Petrogale lateralis (MacDonnell Ranges race) in the Anangu Pitjantjatjara Yankunytjatjara (APY) Lands, South Australia. Method Analyses were conducted at four spatial scales: (1) across the Central Ranges IBRA Region (regional scale); (2) on hills in the APY Lands at which P. lateralis is extant and extinct (site scale); (3) at ‘core’ and ‘non-core’ areas within those hills (hillside scale); and (4) at rocky refuges. The maximum entropy approach through the software MaxEnt was used for the analysis at the regional scale. At the remaining scales, fieldwork was used to collect, and regression modelling to analyse, data. Key results At the regional scale, presence was associated with slope and geology. At the site scale, aspect, rock abundance and habitat type are likely to have facilitated animal persistence at extant sites. At the hillside scale, the aspect, vegetation type and rock complexity of core areas are likely to have contributed to their higher use. Size, exposure and accessibility were significant predictors of the use of rocky refuges. Conclusions All four spatial scales yielded novel information on the habitat associations of P. lateralis, supporting previous researchers’ suggestions that habitat modelling should be conducted at multiple spatial scales. Implications The study exemplifies the utility of combining MaxEnt modelling with fieldwork-derived data. The results may have conservation implications for this threatened race, and may also provide a model for other studies of faunal habitat associations.

Fate of the Mongooses and the Genet (Carnivora) in Mediterranean Europe: None Native, All Invasive?

The Mediterranean Basin (MB), connected by cultural exchanges since prehistoric times, provides an outstanding framework to study species introductions, notably in mammals. Carnivores are among the most successful mammalian invaders. As such, a number of middle-sized representatives (“mesocarnivores”) such as the domestic cat and mongooses have been pinpointed for their deleterious impact on the native fauna. In the MB, three species of mongooses (Herpestidae) and one genet (Viverridae) are or have recently been recorded and none of them has been considered native: the Indian grey mongoose Herpestes edwardsii, the small Indian mongoose H. auropunctatus, the Egyptian mongoose H. ichneumon, and the common genet Genetta genetta. In order to clarify the history of introduction and status of the mongooses and genet in Europe, I review various bodies of evidence including (1) their natural history and relationships with humans in their native ranges, (2) their history of introduction in Europe, (3) the enlightenments—and sometimes contradictions—brought by recent genetic analyses on their dispersal histories, and (4) their range dynamics and ecological interactions with the European fauna. The species of herpestids and viverrids present in Europe fall into three categories: (1) introduced and spreading (G. genetta, H. auropunctatus), (2) introduced and extinct (H. edwardsii), and (3) natural disperser and spreading (H. ichneumon). In view of the reviewed evidence, there is weak support for a deleterious impact of the mongooses and genet on the European fauna (except possibly on the herpetofauna of small Adriatic islands in the case of H. auropunctatus), notably in comparison with genuine invasive species such as the black rat and the domestic cat. Rather than inefficient control programs such as those targeting H. ichneumon in Portugal and H. auropunctatus in Croatia, we suggest that a greater attention is focused on the restoration of large Carnivores (the natural regulators of mesocarnivore populations), mesocarnivore communities and natural habitats, to contribute to a more sustainable way of “managing” the mongooses and genet in Europe.

Combining physiological threshold knowledge to species distribution models is key to improving forecasts of the future niche for macroalgae

Species distribution models (SDM) are a useful tool for predicting species range shifts in response to global warming. However, they do not explore the mechanisms underlying biological processes, making it difficult to predict shifts outside the environmental gradient where the model was trained. In this study, we combine correlative SDMs and knowledge on physiological limits to provide more robust predictions. The thermal thresholds obtained in growth and survival experiments were used as proxies of the fundamental niches of two foundational marine macrophytes. The geographic projections of these species' distributions obtained using these thresholds and existing SDMs were similar in areas where the species are either absent-rare or frequent and where their potential and realized niches match, reaching consensus predictions. The cold-temperate foundational seaweed Himanthalia elongata was predicted to become extinct at its southern limit in northern Spain in response to global warming, whereas the occupancy of southern-lusitanic Bifurcaria bifurcata was expected to increase. Combined approaches such as this one may also highlight geographic areas where models disagree potentially due to biotic factors. Physiological thresholds alone tended to over-predict species prevalence, as they cannot identify absences in climatic conditions within the species' range of physiological tolerance or at the optima. Although SDMs tended to have higher sensitivity than threshold models, they may include regressions that do not reflect causal mechanisms, constraining their predictive power. We present a simple example of how combining correlative and mechanistic knowledge provides a rapid way to gain insight into a species' niche resulting in consistent predictions and highlighting potential sources of uncertainty in forecasted responses to climate change.