scholarly journals El Modelling potential distribution of the endemic ringtail (Bassariscus astutus saxicola) on an island in the Gulf of California

Author(s):  
Gustavo Arnaud ◽  
Sarahi Sandoval ◽  
Jonatgan G. Escobar-Flores ◽  
Rigel Sansores Sánchez

Objective: Analyze the topography of the island with a digital elevation model (DEM) at 30 m spatial resolution and generate the first distribution model for an endemic carnivore from the islands of the Gulf of California. Design/Methodology/Approach: This study employed the Maxent species distribution model to find the distribution of the ringtail in its habitat on Espíritu Santo Island. In 2015–2016, through four surveys, ringtails were trapped in eight glens on the west of the island. A total of 74 individuals were captured, with nine recaptures. Results: The variables with the greatest contributions to the models were elevation, contributing 71.6%; heat load index 15% and ruggedness 11.8%. The model predicts > 0.5 probabilities of presence of this carnivore in 3,018 hectares of the island. We obtained a high AUC value (0.928), which indicates that the model is accurate, and subsequently confirmed it with a value of pAUC = 1.917. Study Limitations/Implications: The habitat of the ringtail (Bassariscus astutus saxicola) was little known mainly because it is an endemic species. And there was not a published article that will show its distribution within the island. Conclusions: This model shows that topographic variables are useful to explain the potential distribution of the ringtail, mainly because the topography is related to sites that can offer thermal refuge, abundance of food, and escape routes from predators, among other features.

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e12001
Author(s):  
Jinbo Fu ◽  
Linlin Zhao ◽  
Changdong Liu ◽  
Bin Sun

As IUCN critically vulnerable species,the Indo-Pacific humpback dolphins (Sousa chinensis) have attracted great public attention in recent years. The threats of human disturbance and environmental pollution to this population have been documented extensively. However, research on the sensitivity of this species to climate change is lacking. To understand the effect of climate change on the potential distribution of Sousa chinensis, we developed a weighted ensemble model based on 82 occurrence records and six predictor variables (e.g., ocean depth, distance to shore, mean temperature, salinity, ice thickness, and current velocity). According to the true skill statistic (TSS) and the area under the receiver operating characteristic curve (AUC), our ensemble model presented higher prediction precision than most of the single-algorithm models. It also indicated that ocean depth and distance to shore were the most important predictors in shaping the distribution patterns. The projections for the 2050s and 2100s from our ensemble model indicated a severe adverse impact of climate change on the Sousa chinensis habitat. Over 75% and 80% of the suitable habitat in the present day will be lost in all representative concentration pathway emission scenarios (RCPS) in the 2050s and 2100s, respectively. With the increased numbers of records of stranding and deaths of Sousa chinensis in recent years, strict management regulations and conservation plans are urgent to safeguard the current suitable habitats. Due to habitat contraction and poleward shift in the future, adaptive management strategies, including designing new reserves and adjusting the location and range of reserves according to the geographical distribution of Sousa chinensis, should be formulated to minimize the impacts of climate change on this species.


2020 ◽  
Vol 46 (2) ◽  
pp. 395-411 ◽  
Author(s):  
E. Serrano ◽  
A. Pisabarro ◽  
J.I. López-Moreno ◽  
M. Gómez-Lende ◽  
R. Martín-Moreno ◽  
...  

This paper shows the creation of a map of frozen ground potential for the Tucarroya valley in Ordesa National Park. To create this map, it was necessary to combine the identified landforms associated to the presence of frozen ground by fieldwork, ground temperature data continuously recorded during two years by automatic loggers, a Basal Temperature of Snow (BTS) survey, and predictor variables derived from a high resolution Digital Elevation Model (DEM). Four environments have been differentiated: unfrozen ground, seasonal frozen ground, possible permafrost and probable permafrost. The map confirms a very limited variety and extension of permafrost, above 2700 m a.s.l. on gentle and shadowed slopes. Seasonal frozen ground is the most common thermal regime, as it can be developed above 2500 m a.s.l. Snow-pack duration and thickness tightly control the duration of frozen ground and the freezing-thawing cycles. Frost activity and unfrozen ground is restricted from 2570 to 2750 m a.s.l.


2020 ◽  
Vol 57 (5) ◽  
pp. 1659-1667 ◽  
Author(s):  
Huercha ◽  
Ruiqi Song ◽  
Ying Ma ◽  
Zhengxiang Hu ◽  
Yingke Li ◽  
...  

Abstract Dermacentor marginatus Sulkzer is a common tick species found in the Xinjiang Uygur Autonomous Region (XUAR) of China, and is a vector for a variety of pathogens. To determine the potential distribution of this tick species in Xinjiang, a metadata containing 84 D. marginatus presence records combined with four localities from field collection were used for MaxEnt modeling to predict potential distribution of this tick species. Identification of tick samples showed 756 of 988 (76%) were D. marginatus. MaxEnt modeling results indicated that the potential distribution of this tick species was mainly confined to northern XUAR. Highly suitable areas included west side of Altay mountain, west rim of Junggar basin, and Yili River valley in the study area. The model showed an AUC value of 0.838 ± 0.063 (SD), based on 10-fold cross-validation. Although tick presence records used for modeling were limited, this is the first regional tick distribution model for D. marginatus in Xinjiang. The model will be helpful in assessing the risk of tick-borne diseases to human and animals in the region.


Forests ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 429
Author(s):  
Yadong Xu ◽  
Yi Huang ◽  
Huiru Zhao ◽  
Meiling Yang ◽  
Yuqi Zhuang ◽  
...  

Cypripedium japonicum is an endangered terrestrial orchid species with high ornamental and medicinal value. As global warming continues to intensify, the survival of C. japonicum will be further challenged. Understanding the impact of climate change on its potential distribution is of great significance to conserve this species. In this study, we established an ensemble species distribution model based on occurrence records of C. japonicum and 13 environmental variables to predict its potential distribution under current and future climatic conditions. The results show that the true skill statistic (TSS), Cohen’s kappa statistic (Kappa), and the area under the receiver operating characteristic curve (AUC) values of the ensemble model were 0.968, 0.906, and 0.995, respectively, providing more robust predictions. The key environmental variables affecting the distribution of C. japonicum were the precipitation in the warmest quarter (Bio18) and the mean temperature in the driest quarter (Bio9). Under future climatic conditions, the total suitable habitat of C. japonicum will increase slightly and tend to migrate northwestward, but the highly suitable areas will be severely lost. By 2070, the loss of its highly suitable habitat area will reach 57.69–72.24% under representative concentration pathway (RCP) 4.5 and 8.5 respectively, and the highly suitable habitats in Zhejiang and Anhui will almost disappear. It is noteworthy that the highly suitable habitat of C. japonicum has never crossed the Qinba mountainous area during the migration process of the suitable habitat to the northwest. Meanwhile, as the best-preserved area of highly suitable habitat for C. japonicum in the future, the Qinba mountainous area is of great significance to protect the wild germplasm resources of C. japonicum. In addition, we found that most of the changes predicted for 2070 will already be seen in 2050; the problem of climate change may be more urgent than it is believed.


2020 ◽  
Vol 113 (4) ◽  
pp. 1702-1710
Author(s):  
Alexandre Silva de Paula ◽  
Carlos Barreto

Abstract Nysius simulans (Stål) is a suctorial, fluid feeding herbivore that can transmit toxins and spread pathogens via saliva and is an economically important pest for soybean in South America. Currently, N. simulans in soybean is predominantly found in Argentina, but future changes in the distribution from both dispersal and range shifts due to climate change may affect soybean cultivation in southern South America. We developed a species distribution model to examine the distribution range of N. simulans. We compared the potential distribution of N. simulans under current and future projected climatic conditions in order to identify future areas of natural occurrence with ecological niche models using Maxent. Current records of N. simulans show that while the species is present in Argentina, and some areas of Brazil, Paraguay, Peru, and Uruguay, our models suggest that many new suitable areas will be available for N. simulans under climate change including other regions of Argentina, and southern Chile. Our results also predict potential future range shifts and distributions into Bolivia, but not Peru nor Brazil. In our model, seasonal trends in temperature were shown to have the greatest contribution to the potential distribution, whereas isothermality (i.e., temperature variability) was correlated to potential future distribution ranges. We conclude that current populations of N. simulans may be expanding its distribution range by diffusion (i.e., range expansion over generations at the margins of populations), and regions with potential future N. simulans distribution should be closely monitored.


2013 ◽  
pp. 1 ◽  
Author(s):  
Jason Gibbs ◽  
Sheila Dumesh

A new species from Colima, Mexico, Lasioglossum (Eickwortia) hienae Gibbs & Dumesh, new species, is described and illustrated.  Lasioglossum hienae is distinguished from related species based on a combination of morphological, geographical, and molecular evidence.  A species distribution model is used to predict the potential distribution of the known species of L. (Eickwortia).  An identification key is provided.


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