Habitat selection of resident and non-resident gray wolves: implications for habitat connectivity

Habitat selection studies facilitate assessing and predicting species distributions and habitat connectivity, but habitat selection can vary temporally and among individuals, which is often ignored. We used GPS telemetry data from 96 Gray wolves (Canis lupus) in the western Great Lakes region of the USA to assess differences in habitat selection while wolves exhibited resident (territorial) or non-resident (dispersing or floating) movements and discuss implications for habitat connectivity. We used a step-selection function (SSF) to assess habitat selection by wolves exhibiting resident or non-resident movements, and modeled circuit connectivity throughout the western Great Lakes region. Wolves selected for natural land cover and against areas with high road densities, with no differences in selection among wolves when resident, dispersing, or floating. Similar habitat selection between resident and non-resident wolves may be due to similarity in environmental conditions, when non-resident movements occur largely within established wolf range rather than near the periphery or beyond the species range. Alternatively, non-resident wolves may travel through occupied territories because higher food availability or lower human disturbance outweighs risks posed by conspecifics. Finally, an absence of differences in habitat selection between resident and non-resident wolf movements may be due to other unknown reasons. We recommend considering context-dependency when evaluating differences in movements and habitat use between resident and non-resident individuals. Our results also provide independent validation of a previous species distribution model and connectivity analysis suggesting most potential wolf habitat in the western Great Lakes region is occupied, with limited connectivity to unoccupied habitat.

Did decades of glyphosate use have selected for resistant amphibians in agricultural habitats?

Glyphosate-based herbicides are used worldwide, and glyphosate's primary metabolite (aminomethylphosphonic acid: AMPA), is globally retrieved in surface waters. AMPA induces various adverse effects on aquatic wildlife, including selective mortality, which suggests that glyphosate exposure may have selected for AMPA-resistant individuals. We tested this hypothesis using spined toads (Bufo spinosus), an amphibian found in a variety of habitats, from AMPA-exposed agricultural lands to AMPA-free forested areas. We predicted that the offspring of individuals originating from agricultural habitats would develop AMPA-resistance - and be less prone to develop adverse effects from- AMPA exposure. To investigate this question, we performed a common garden brood-rearing experiment. The embryos and larvae of 40 spined toad pairs captured in agricultural and forest ponds were exposed either to an environmental relevant concentration of AMPA (0.4 μg L^-1) or to control conditions (n = 8160 embryos, n = 240 tadpoles). We monitored development durations, developmental abnormalities and morphology, measured across key developmental stages. Although we observed significant effects of AMPA on fitness parameters in each group, these effects were not exacerbated in individuals from AMPA-free habitats. We suggest that temporal and/or spatial dynamics of contamination, as well as gene flow between exposed and preserved populations, may hinder adaptive divergence between populations. Yet, we show strong adverse effects of AMPA exposure at early developmental stages. AMPA could therefore be one of the numerous causes of declining wild amphibian populations.

Sex Differences Dictate the Movement Patterns of Striped Hyenas, Hyaena hyaena, in a Human-Dominated Landscape

Large-carnivore populations have experienced significant declines in the past centuries in extended parts of the world. Habitat loss, fragmentation, and depletion of natural resources are some of the main causes of this decline. Consequently, behavioral flexibility, enabling the exploitation of anthropogenic food resources in highly disturbed human-dominated landscapes, is becoming critical for the survival of large carnivores. These behavioral changes increase the potential for human-large carnivore conflict and can further intensify carnivore persecution. Here, we examine how land cover types (representing a gradient of anthropogenic disturbance) alter the behavior of striped hyenas (Hyaena hyaena) in a human-dominated landscape in Israel, and whether differences in life history between males and females affect their reaction to such disturbances and consequently their level of exposure to humans. We used a Hidden Markov Model on GPS-tracking data for seven striped hyenas to segment individual-night trajectories into behavioral states (resting, searching, and traveling). We then used multinomial logistic regression to model hyenas’ behavioral state as a function of the interaction between land cover and sex. Females traveled less than males both in terms of average distance traveled per hour, per night, and nightly net displacement. Most steps were classified as “searching” for females and as “traveling” for males. Female hyenas spent a higher proportion of time in human-dominated areas and a lower proportion in natural areas compared to males, and they were also more likely to be found close to settlements than males. Females changed their time allocation between natural and human-dominated areas, spending more time resting than traveling in natural areas but not in human-dominated ones; males spent more time searching than resting in human-dominated areas but were equally likely to rest or search in natural ones. The differences in life history between male and female hyenas may reflect different motivations for space use as a means to optimize fitness, which affects their exposure to humans and therefore their potential involvement in human-hyenas conflict. Understanding the mechanisms that lead to behavioral change in response to human disturbance is important for adaptive management and promoting human large-carnivores co-existence in general.

Assessing behaviour states of a forest carnivore in a road-dominated landscape using Hidden Markov Models

Anthropogenic infrastructures and land-use changes are major threats to animal movements across heterogeneous landscapes. Yet, the behavioural consequences of such constraints remain poorly understood. We investigated the relationship between the behaviour of the Common genet (Genetta genetta) and road proximity, within a dominant mixed forest-agricultural landscape in southern Portugal, fragmented by roads. Specifically, we aimed to: (i) identify and characterise the behavioural states displayed by genets and related movement patterns; and (ii) understand how behavioural states are influenced by proximity to main paved roads and landscape features. We used a multivariate Hidden Markov Model (HMM) to characterise the fine-scale movements (10-min fixes GPS) of seven genets tracked during 187 nights (mean 27 days per individual) during the period 2016–2019, using distance to major paved roads and landscape features as predictors. Our findings indicated that genet’s movement patterns were composed of three basic behavioural states, classified as “resting” (short step-lengths [mean = 10.6 m] and highly tortuous), “foraging” (intermediate step-lengths [mean = 46.1 m] and with a wide range in turning angle) and “travelling” (longer step-lengths [mean = 113.7 m] and mainly linear movements). Within the genet’s main activity-period (17.00 h-08.00 h), the movement model predicts that genets spend 36.7% of their time travelling, 35.4% foraging and 28.0% resting. The probability of genets displaying the travelling state was highest in areas far away from roads (> 500 m), whereas foraging and resting states were more likely in areas relatively close to roads (up to 500 m). Landscape features also had a pronounced effect on behaviour state occurrence. More specifically, travelling was most likely to occur in areas with lower forest edge density and close to riparian habitats, while foraging was more likely to occur in areas with higher forest edge density and far away from riparian habitats. The results suggest that, although roads represent a behavioural barrier to the movement of genets, they also take advantage of road proximity as foraging areas. Our study demonstrates that the HMM approach is useful for disentangling movement behaviour and understanding how animals respond to roadsides and fragmented habitats. We emphasise that road-engaged stakeholders need to consider movement behaviour of genets when targeting management practices to maximise road permeability for wildlife.

Exploratory and territorial behavior in a reintroduced population of Iberian lynx

In reintroduction projects, an analysis of dispersal, exploratory movements and territorial behavior of the species concerned offers valuable information on the adaptive management of threatened species and provides a basis for the management of future reintroductions. This is the case of the Iberian lynx (Lynx pardinus) an endemic and endangered species reintroduced in Extremadura (Spain) in 2014. We analysed spatial data from 32 individuals just after their reintroduction. Our findings show exploratory movements sufficient to colonise and connect population nuclei within a radius of about 50 km of the reintroduction area. No significant differences were found in the exploratory movements capacity or in any directionality of males and females. Our results showed an effect of sex on the sizes of the territories established, as well as an inverse relationship between them and the time elapsed since release. No effects of rabbit abundance and lynx density on the size of territories are occurring during the early stages of reintroduction. On average, the territories of reintroduced individuals were less stable than those previously described in natural populations. Findings indicate that the reintroduced population has successfully been established but it takes more than 5 years to stabilize the territories in the area. Exploratory movements of reintroduced lynx can be large and in any direction, even when there is still a lot of high quality habitat available, which should be taken into account when reintroducing species, especially terrestrial carnivores.

Deterministic, random, or in between? Inferring the randomness level of wildlife movements

BACKGROUND

When assessing connectivity, it is crucial to rely on accurate modeling frameworks that consider species movement preferences and patterns. One important aspect is the level of randomness or unpredictability in the route selection. In this respect, traditional approaches (based on least-cost path or circuit theory) consider species movements unrealistically as totally deterministic or as totally random. A recent approach (randomized shortest path) advocates for choosing intermediate levels of randomness through a single parameter. This parameter may be optimized by validating connectivity surfaces developed from different levels of randomness against observed movement data. However, connectivity models are seldom validated, and it is still unclear how to approach this task. To address this knowledge gap, this paper aims at comparing different validation methods to infer the optimal randomness level in connectivity studies. Additionally, we aimed to disentangle the practical consequences of applying traditional connectivity approaches versus using an optimized level of movement randomness when delineating corridors.

METHODS

These objectives were accomplished through the study case of the Iberian lynx, an endangered species whose maintenance and recovery depend on the current connectivity among its population nuclei. We firstly determined a conductance surface based on point selection functions accounting for the behavioral state (territorial or exploratory) of individuals. Secondly, we identified the level of randomness that better fits lynxes' movements with independent GPS locations and different validation techniques. Lastly, we delineated corridors between lynx population nuclei through a) the randomized shortest path approach and the extreme and optimal levels of randomness of each validation method, and b) the traditional connectivity approaches.

RESULTS

According to all used validation methodologies, models with intermediate levels of randomness outperformed those with extreme randomness levels representing totally deterministic or random movements. We found differences in the optimal randomness level among validation methods but similar results in the delineation of corridors. Our results also revealed that models with extreme randomness levels (deterministic and random walk) of the randomized path approach provided equivalent corridor networks to those from traditional approaches. Moreover, these corridor networks calculated with traditional approaches showed notable differences in patterns from the corridor network calculated with an optimized randomness level.

CONCLUSIONS

Here we presented a connectivity model with a solid biological basis that calibrates the level of movement randomness and is supported by comprehensive validation methods. It is thus a step forward in the search and evaluation of connectivity approaches that lead to improved, efficient, and successful management actions.

Multiscale assessment of functional connectivity: Landscape genetics of eastern indigo snakes in an anthropogenically fragmented landscape in central Florida

Landscape features can strongly influence gene flow and the strength and direction of these effects may vary across spatial scales. However, few studies have evaluated methodological approaches for selecting spatial scales in landscape genetics analyses, in part because of computational challenges associated with optimizing landscape resistance surfaces (LRS). We used the federally threatened eastern indigo snake (Drymarchon couperi) in central Florida as a case study with which to compare the importance of landscape features and their scales of effect in influencing gene flow. We used genetic algorithms (ResistanceGA) to empirically optimize LRS using categorical land cover surfaces, multiscale resource selection surfaces (RSS), and four combinations of landscape covariates measured at multiple spatial scales (multisurface multiscale LRS). We compared LRS where scale was selected using pseudo- and full optimization. Multisurface multiscale LRS received more empirical support than LRS optimized from categorical land cover surfaces or RSS. Multiscale LRS with scale selected using full optimization generally outperformed those with scale selected using pseudo-optimization. Multiscale LRS with large spatial scales (1200-1800 m) received the most empirical support. Our results highlight the importance of considering landscape features across multiple spatial scales in landscape genetic analyses, particularly broad scales relative to species movement potential. Different effects of scale on home range-level movements and dispersal could explain weak associations between habitat suitability and gene flow in other studies. Our results also demonstrate the importance of large tracts of undeveloped upland habitat with heterogenous vegetation communities and low urbanization for promoting indigo snake connectivity.

Social Innovation in Olive Oil Cooperatives: A Case Study in Southern Spain

Recent years have witnessed a notable increase in the implementation of social innovation strategies for creating products with major social impact. Despite the lack of conceptual clarity still surrounding the term, social innovation, as a participatory research method, is finding scope for growth in agricultural cooperatives, whether in the areas of R&D and knowledge transfer, or in the commercialization of innovative products. Society has underscored the need for change in the environment and the implementation of new projects that help improve socioeconomic living conditions, promoting territorial development through social transformation. In the case of cooperativism in the olive oil industry in southern Spain, cooperatives are responsible for 70% of the oil produced there. As such, the actions carried out under their influence have a huge impact on the population and serve as tools that anchor people to their municipalities. This article analyses a case study from an olive oil cooperative, exploring the development of a social innovation project involving knowledge transfer and public awareness-raising through the label of an early harvest olive oil called “Primer Día de Cosecha” (First Day of Harvest). It also assesses the impact of the project on the population of the Andalusian municipality of Bailén (Jaén).

Breaking barriers: Iberian Lynx Lynx pardinus Temminck, 1827 (Mammalia: Carnivora: Felidae) colonizing Olive groves

In recent years, the Andújar-Cardeña Iberian Lynx Lynx pardinus population has grown both in number and in occupied surface area.  This feline has spread into areas surrounding existing population nuclei and occupied new habitats including human-dominated areas and tree crops.  Here we describe this colonization process and the evolution of the Iberian Lynx populations in the Olive Olea europaea groves that surround typical Lynx scrub habitats in Andújar-Cardeña.  Our findings were obtained through radio-tracking, camera trapping and European Rabbit Oryctolagus cuniculus monitoring.  Two colonized areas—Zocueca and Marmolejo-Montoro—were identified in which Olive cultivation is predominant.  Since 2011, a total of 45 and 50 different individuals have been detected in Zocueca and Marmolejo-Montoro, respectively.  At present, 19 individuals are known to live in Zocueca and 29 in Marmolejo-Montoro.  The main cause of mortality is road-kills.  Our results suggest that the Iberian Lynx is capable of colonizing human-modified areas such as agricultural land provided that they can support high-density Rabbit populations and the causes of non-natural mortality are minimized.

Iberian Lynx Lynx pardinus Temminck, 1827 (Mammalia: Carnivora: Felidae) in central Spain: trophic niche of an isolated population

Understanding predator-prey relationships is fundamental to develop effective conservation plans.  Between 2015 and 2018, we combed 21 transects, each 7km long, searching for Iberian Lynx Lynx pardinus scat within the province of Madrid in central Spain.  In order to minimise inherent subjectivity of visual identification as much as possible, we performed a double specific nested polymerase chain reaction (PCR) followed by a primer extension assay addressed to two Iberian Lynx diagnostic single nucleotide polymorphisms.  Forty-six scat samples were positively identified as belonging to Iberian Lynx through genetic analysis.  From these, we extracted remains of consumed prey, which we determined to the lowest possible taxonomic level, mainly through hair identification.  Identified prey was divided into four types: lagomorphs, small mammals, birds, and ungulates.  The species’ diet composition was described based on the frequency of occurrence (FO) of each prey and niche breadth, and also compared with prior knowledge of the species using four prior studies as a comparative reference through the calculation of the niche overlap value.  The FO of lagomorphs (39%) was the lowest, while the FO of small mammals (54%) was the highest recorded to date.  The niche breath (0.36) was higher than recorded in prior studies, but still showing the specialist character of the Iberian Lynx.  Niche overlap was low (C = 0.49), showing differences in trophic niche between the population in our study area and the one studied in southern Spain.  This indicates that the Iberian Lynx is adept at switching its main prey, an ability that has previously been firmly rejected.  It is, however, capable of adapting to alternative prey more often than recorded to date, which could be a behavioural response to the patchy distribution of European Rabbit Oryctolagus cuniculus in the study area.

Planning the peninsula-wide recovery of the Iberian lynx: identification of favourable habitat areas

The creation of new populations through reintroductions in their former range is still necessary for the long-term conservation of the Iberian lynx (Lynx pardinus). A large-scale assessment of habitat suitability is a necessary prerequisite for evaluating the possibility of carrying out lynx reintroductions. We modelled habitat suitability for the Iberian lynx in the Iberian Peninsula using MaxEnt. Lynx presence data for 2010–2013 from Andujar-Cardeña and Doñana populations were used. Habitat variables were quantified using the CORINE Land Cover. This habitat suitability model predicted an environmentally suitable area of 87,747 km2, which represents 14.08% of the whole Iberian Peninsula. Of the total suitable habitat identified, 45% is located in a large continuous area in the south-western quadrant coinciding with the historical range of the species in the mid-20th century. However, there are also relevant patches mainly in the north-eastern quadrant. About 55% of the potential area suitable for the lynx falls outside protected areas. If Iberian lynx populations are to attain levels that will facilitate their long-term survival, it will be necessary to consider potential habitat for the species throughout the whole of the Iberian Peninsula.

Competition alters seasonal resource selection and promotes use of invasive shrubs by an imperiled native cottontail

Many ecosystems face multiple invaders, and interactions among invasive and native species may complicate conservation efforts for imperiled species. Examination of fine-scale resource selection can be used to detect patterns in habitat selection resulting from species interactions and assess the value of specific resources, including invasive plants, to wildlife. We used animal location data with mixed-effects resource selection models to examine seasonal competitive interactions and species-specific selection for forage and cover resources by an imperiled native lagomorph, the New England cottontail Sylvilagus transitionalis and its nonnative competitor, the eastern cottontail S. floridanus in the eastern Hudson Valley, NY. We found evidence that resource selection by New England cottontails depended on the relative prevalence of eastern cottontails to New England cottontails. Where eastern cottontails were less prevalent New England cottontail selected for resources characteristic of early successional shrublands. Where eastern cottontails were more prevalent, New England cottontails selected for resources characteristic of later successional shrublands. New England cottontail use of certain invasive shrubs depended on the prevalence of eastern cottontails relative to New England cottontails, suggesting response to invasive plants is confounded by interactions with a nonnative competitor. Our results further emphasize the need for conservation efforts to consider invasive management within the ecosystem context. We demonstrate the utility of resource selection studies to assist in this regard by exploring competitive interactions in the absence of removal studies, while simultaneously assessing the impact of habitat components such as invasive vegetation on species of conservation concern. Synthesis and applications Resource selection studies can be directly applied to inform ongoing species conservation where multiple invaders are present or where species interactions influence resource selection. Fine-scale assessments of resource selection, similar to those presented here, can be used to selectively manage habitat to benefit desired species within the ecosystem context.

Protected areas in the world's ecoregions: How well connected are they?

Protected areas (PAs) are the main instrument for biodiversity conservation, which has triggered the development of numerous indicators and assessments on their coverage, performance and efficiency. The connectivity of the PA networks at a global scale has however been much less explored; previous studies have either focused on particular regions of the world or have only considered some types of PAs. Here we present, and globally assess, ProtConn, an indicator of PA connectivity that (i) quantifies the percentage of a study region covered by protected connected lands, (ii) can be partitioned in several components depicting different categories of land (unprotected, protected or transboundary) through which movement between protected locations may occur, (iii) is easy to communicate, to compare with PA coverage and to use in the assessment of global targets for PA systems. We apply ProtConn to evaluate the connectivity of the PA networks in all terrestrial ecoregions of the world as of June 2016, considering a range of median dispersal distances (1-100 km) encompassing the dispersal abilities of the large majority of terrestrial vertebrates. We found that 9.3% of the world is covered by protected connected lands (average for all the world's ecoregions) for a reference dispersal distance of 10 km, increasing up to 11.7% for the largest dispersal distance considered of 100 km. These percentages are considerably smaller than the global PA coverage of 14.7%, indicating that the spatial arrangement of PAs is only partially successful in ensuring connectivity of protected lands. The connectivity of PAs largely differed across ecoregions. Only about a third of the world's ecoregions currently meet the Aichi Target of having 17% of the terrestrial realm covered by well-connected systems of PAs. Finally, our findings suggest that PAs with less strict management objectives (allowing the sustainable use of resources) may play a fundamental role in upholding the connectivity of the PA systems. Our analyses and indicator make it possible to identify where on the globe additional efforts are most needed in expanding or reinforcing the connectivity of PA systems, and can be also used to assess whether newly designated sites provide effective connectivity gains in the PA system by acting as corridors or stepping stones between other PAs. The results of the ProtConn indicator are available, together with a suite of other global PA indicators, in the Digital Observatory for Protected Areas of the Joint Research Centre of the European Commission.

A Composite Network Approach for Assessing Multi-Species Connectivity: An Application to Road Defragmentation Prioritisation

One of the biggest challenges in large-scale conservation is quantifying connectivity at broad geographic scales and for a large set of species. Because connectivity analyses can be computationally intensive, and the planning process quite complex when multiple taxa are involved, assessing connectivity at large spatial extents for many species turns to be often intractable. Such limitation results in that conducted assessments are often partial by focusing on a few key species only, or are generic by considering a range of dispersal distances and a fixed set of areas to connect that are not directly linked to the actual spatial distribution or mobility of particular species. By using a graph theory framework, here we propose an approach to reduce computational effort and effectively consider large assemblages of species in obtaining multi-species connectivity priorities. We demonstrate the potential of the approach by identifying defragmentation priorities in the Italian road network focusing on medium and large terrestrial mammals. We show that by combining probabilistic species graphs prior to conducting the network analysis (i) it is possible to analyse connectivity once for all species simultaneously, obtaining conservation or restoration priorities that apply for the entire species assemblage; and that (ii) those priorities are well aligned with the ones that would be obtained by aggregating the results of separate connectivity analysis for each of the individual species. This approach offers great opportunities to extend connectivity assessments to large assemblages of species and broad geographic scales.