Sex-specific connectivity modelling for brown bear conservation in the Carpathian Mountains

M Pino García-Sánchez,Georgeta Ionescu,Mihai Fedorca,Joaquín Solana-Gutiérrez,Ovidiu Ionescu,Ancuta Fedorca,Ramon Jurj,Sergio González-Ávila,Marius Popa

doi:10.1007/s10980-021-01367-8

Abstract

ContextRomania is currently one of the best-connected landscapes, with high-quality habitats and a high density of brown bears. However, regional development measures are needed for the nation’s economic growth, and without responsible government actions, these measures pose a threat to brown bear connectivity, a vital pillar of the entire Carpathian region. Despite having important implications for the species conservation, bears sex-specific behaviour has been overlooked in connectivity assessments.ObjectivesThe study’s main goals were to (i) develop sex-specific distribution and connectivity models, (ii) assess the movement patterns differences between females and males, and (iii) identify high-quality areas to be secured for species connectivity conservation.MethodsWe designed a methodological framework based on interdisciplinary approaches and modelling tools for landscape connectivity combined with novel spatial analysis. Telemetry data of sixteen bears (females and males) were utilized to predict habitat selection (MaxEnt), and circuit-theoretic approaches (Circuitscape) were applied to identify the potential movement corridors of both sexes and high-priority areas.ResultsThe obtained results provided new evidence on the uneven movement patterns and pathways used by males and females in the study region. Males’ movement preferences were related to river shores and dense forest coverage areas, avoiding urban areas, while females were predicted to move across forested and open areas and were more tolerant to human‐modified areas. Three high-quality areas were delineated for both sexes, and connectivity conservation efforts are needed due to the vicinity of anthropic pressures.ConclusionsThis study depicts the usefulness of combining interdisciplinary approaches and provides planners, managers, and decision-makers with practical solutions to address sustainable design and management within the intervened landscapes. Using separate female and male spatial models for leading management and conservation measures, setting connectivity targets within environmental and impact assessments while adopting conservation easements could secure a safety network for biodiversity conservation in the Carpathians.

Highlights

The Carpathian range is known as Europe’s last remaining refuge for large carnivore species (Webster et al 2001), such as the brown bear (Ursus arctos)
We aimed to expand upon previous connectivity analyses conducted for the brown bear (Posillico et al 2004; Mateo-Sanchez et al 2015a, b; Ziołkowska et al 2016), by modelling the most likely movement routes of this species at the regional scale in the central Carpathian territory in Romania
The methodology applied to achieve the study goals consisted of the following steps: (a) define the study area, (b) filter the telemetry GPS data and select species’ presences, linked to exploratory movements and environmental covariates, (c) model habitat suitability based on MaxEnt and derive sex-specific resistance surfaces, (d) model connectivity using Circuitscape and implement a ‘wall-to-wall’ approach, (e) quantify sex-specific similarities in the obtained models, and (f) develop a novel procedure for identifying high-priority areas in the main movement pathways potentially used for dispersal by the species (Fig. 1)

Summary

Introduction

The Carpathian range is known as Europe’s last remaining refuge for large carnivore species (Webster et al 2001), such as the brown bear (Ursus arctos). The human footprint and the high population density of the brown bear in this area increase the conflict between the predator’s behaviour and local economic activities, especially livestock. The abovementioned human-related factors threatening biodiversity in the Carpathian region generate both landscape fragmentation and habitat losses and affect the species’ movement pathways. Rapid climate change effects threaten the home ranges of wildlife, forcing species to shift their distribution areas in search of quiet zones and suitable habitats (Walther et al 2002; Hermes et al 2018; Williams et al 2020). Species need suitable paths to move towards new areas with appropriate conditions, ensuring gene flow among populations (Hilty et al 2020), especially those with large area requirements such as the brown bear (Maanen et al 2006; Fernandez et al 2012). Due to its vast spatial requirements, the brown bear may serve as an umbrella species and, as a tool for prioritizing areas with high conservation value (Roberge and Angelstam 2004; Liu et al 2018; Fedorca et al 2020; Williamson et al 2020)

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Conclusion