scholarly journals Resistance-Based Connectivity Model to Construct Corridors of the Przewalski’s Gazelle (Procapra Przewalskii) in Fragmented Landscape

2021 ◽  
Vol 13 (4) ◽  
pp. 1656
Author(s):  
Jingjie Zhang ◽  
Feng Jiang ◽  
Zhenyuan Cai ◽  
Yunchuan Dai ◽  
Daoxin Liu ◽  
...  

Habitat connectivity is indispensable for the survival of species that occupy a small habitat area and have isolated habitat patches from each other. At present, the development of human economy squeezes the living space of wildlife and interferes and hinders the dispersal of species. The Przewalski’s gazelle (Procapra przewalskii) is one of the most endangered ungulates, which has experienced a significant reduction in population and severe habitat shrinkage. Although the population of this species has recovered to a certain extent, human infrastructure severely hinders the gene flow between several patches of this species. Therefore, we used the maximum entropy (MaxEnt) model to simulate the habitat suitability of the Przewalski’s gazelle. In addition, we combined habitat suitability and ecological characteristics of the species to obtain eight habitat patches. Finally, we used the least-cost path (LCP) and circuit theory based on the resistance model to simulate the landscape network of this species. The results showed that habitat patches and connectivity in the east of the Qinghai Lake were crucial to the communication between populations of the Przewalski gazelle, and our study provided important reference for the distribution of important habitats and the construction of corridor between patches. Our study aimed to provide habitat networks and maintain landscape connectivity for achieving the fundamental goal of protecting and revitalizing populations of the Przewalski’s gazelle.

2020 ◽  
Author(s):  
Jingjing Zhang ◽  
Jennifer L. Pannell ◽  
Bradley S. Case ◽  
Graham Hinchliffe ◽  
Margaret C. Stanley ◽  
...  

AbstractUnderstanding how spatial heterogeneity affects movement and dispersal is critical for maintaining functional connectivity in agroecosystems. Least-cost path models are popular conservation tools to quantify the cost of a species dispersing though the landscapes. However, the variability of species in life history traits and landscape configurations can affect their space-use patterns and should be considered in agroecosystem management aiming to improve functional biodiversity. In this study, we modelled the connectivity properties of native species on a real agroecosystem landscape dominated by sheep and beef farming in north Canterbury, New Zealand, where the recovery of native bird population is desired. We chose two species to act as case studies that were contrasting in their mobility: New Zealand pigeon/kererū (Hemiphaga novaeseelandiae; highly mobile) and southern brown kiwi/tokoeka (Apteryx australis; flightless). Networks of the least-cost paths of kererū and tokoeka were constructed based on their habitat preferences and movement capacities, and we compared and contrasted the connectivity properties and network topographies of their networks. We then compared the network metrics of western side (higher density of forest) with the eastern side (dominated by grazed grassland) of the study area where the vegetation composition was vastly different for both species. The results shown three variables were the most important contributors to the structure of the dispersal networks: the nature of the matrix, spatial structure of vegetation patches, and the gap-crossing ability of the study species. Tokoeka were able to utilise smaller habitat patches as stepping-stones for dispersal, while kererū can select more preferred habitat patches due to their high movement capacity. In contrast to the eastern side, we observed the western/forested side to have more, and stronger, links among habitat patches for both species, due to the presence of several large patches of native forest. Our work suggested that one size does not fit all, rather, conservation strategies that account for species’ life histories and movement traits are required to identify and preserve a connected ecological network.


Author(s):  
V. Prakash ◽  
S. Saran ◽  
G. Talukdar

<p><strong>Abstract.</strong> Most of the protected areas (PAs) in India have a hard boundary; very rarely having a transition zone to minimise the negative human wildlife interface. With increasing anthropogenic pressures, areas surrounding PAs are becoming integral for conservation. Government of India introduced a concept of Eco-sensitive Zones (ESZ) around PAs to minimise anthropogenic pressures and regulate rapid development in these areas. However, delineation of ESZs is a complex process and may take a long time. In this paper, a novel geospatial approach has been presented to delineate ESZ using a species centric approach. A case study using Swamp deer (<i>Rucervus duvaucelli duvaucelli</i>) as focal species was explored for its potential to delineate ESZ around protected area Jhilmil Jheel Conservation Reserve (JJCR) located in Uttarakhand India. Maximum entropy or Maxent model was used to identify habitat suitability. Normalised difference vegetation index (NDVI), altitude, land cover and distance to roads were used as co-variates. Seasonal variations for habitat suitability were also considered. In this study habitat suitability map of swamp deer was further rationalised based on habitat fragmentation and management limitations and proposed as ESZ of JJCR. This approach for delineation of ESZ can be very useful for PAs in India which have focal species and are yet to declare their ESZ.</p>


2020 ◽  
Vol 100 (6) ◽  
pp. 631-643
Author(s):  
Elisa Torretta ◽  
Olivia Dondina ◽  
Claudio Delfoco ◽  
Luca Riboldi ◽  
Valerio Orioli ◽  
...  

AbstractCompared with the rapid expansion across Europe, the golden jackal colonization of Italy is still limited and slow. No study focused on the habitat selection or landscape connectivity for this species was performed in Italy; thus, the potential distribution and dispersal patterns in the country remain unknown. Our objectives were to evaluate the suitability of the Friuli-Venezia Giulia region (north-eastern Italy) for the golden jackal, as well as to identify the ecological corridors connecting the areas currently occupied by the species. Corridors modelling allowed us both to hypothesize the dispersal dynamics occurring in the study region and to identify possible obstacles to future range expansion. We surveyed golden jackal presence in two study areas, covering an area of 500 km2, from March 2017 to February 2018. Using collected data, we modelled the species home-range scale habitat suitability based on an ensemble modelling approach. Subsequently, a habitat suitability prediction at a finer scale was used to estimate landscape resistance, starting from which, we modelled dispersal corridors among areas currently occupied by the species using a factorial least cost path and a cumulative resistant kernel approach. Our results indicated a moderate potential for large parts of the study region to support the occurrence of golden jackal family groups, whose presence seems to be mainly driven by the presence of wide areas covered by broadleaved forests and shrublands and by the absence of wide intensive agricultural areas. The predicted connectivity networks showed that three main permeable corridors are likely to connect golden jackal occurrence areas within the study region, while all the other corridors are characterized by a very low path density. Both the habitat selection and connectivity analyses showed a strong negative impact of the intensive cultivated plain on species stable presence and movement providing critical information for the conservation of the golden jackal in Italy.


Oryx ◽  
2012 ◽  
Vol 46 (1) ◽  
pp. 145-153 ◽  
Author(s):  
Chunlin Li ◽  
Zhigang Jiang ◽  
Xiaoge Ping ◽  
Jing Cai ◽  
Zhangqiang You ◽  
...  

AbstractIn 2008 Przewalski's gazelle Procapra przewalskii, endemic to the Qinghai–Tibetan Plateau, China, was recategorized from Critically Endangered to Endangered on the IUCN Red List. The species is still, however, threatened, and the human population and accompanying domestic livestock are increasing around Qinghai Lake. Here we provide up-to-date information on the distribution and population size of the species, evaluate its current conservation status and discuss the difficulties of protecting this gazelle species. We used both distance sampling and total counts to survey 16 sites where the species has been reported and found it at 13 of these, occupying a total area of c. 250 km2. Population size estimated from distance sampling (1,635) and total counts (1,544) was similar. About 20% of the gazelles located were in newly discovered areas for the species. The results indicate an overall growth in the population of Przewalski's gazelle since 2003, although some subpopulations have declined or been extirpated. In spite of conservation efforts Przewalski's gazelle is still threatened by habitat degradation and loss, habitat fragmentation, fencing, intensified competition with domestic livestock and predation. Further growth of this gazelle population is constrained by limited habitat availability and human–gazelle conflict. We recommend that management and conservation strategies need to incorporate comprehensive knowledge of the gazelle, long-term monitoring, and captive breeding of injured and orphaned gazelles to form a potential pool of individuals for future reintroductions to the historical range of the species outside the Qinghai Lake basin.


Author(s):  
Mauro Fabrizio ◽  
Mirko Di Febbraro ◽  
Marcello D’Amico ◽  
Ludovico Frate ◽  
Federica Roscioni ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document