scholarly journals Predicting multi-species foraging hotspots for marine turtles in the Gulf of Mexico

2020 ◽  
Vol 43 ◽  
pp. 253-266
Author(s):  
I Fujisaki ◽  
KM Hart ◽  
D Bucklin ◽  
AR Iverson ◽  
C Rubio ◽  
...  

Quantifying the distribution of animals and identifying underlying characteristics that define suitable habitat are essential for effective conservation of free-ranging species. Prioritizing areas for conservation is important in managing a geographic extent that has a high level of disturbance and limited conservation resources. We examined the potential use of a species distribution model ensemble for multi-species conservation in marine habitats. Using satellite telemetry locations during foraging as input data, and ensemble ecological niche models, we predicted foraging areas for 2 nesting marine turtle species within the Gulf of Mexico (GoM): Kemp’s ridley Lepidochelys kempii (n = 63) and loggerhead Caretta caretta (n = 63). We considered 7 geophysical, biological, and climatic variables and compared contributing factors for each species’ foraging habitat selection. For both species, predicted suitable foraging habitats encompassed large areas along the GoM coast, but only intersected with each other in relatively small areas. Highly parameterized models resulted in overall greater fits, suggesting that multiple factors influence habitat selection by these species. Model validation results were mixed: cross-validation resulted in high prediction accuracy for both species, but an evaluation against independent data resulted in a low omission rate (5%) for Kemp’s ridleys and a high omission rate (72%) for loggerheads. The relatively small intersection of model-predicted foraging areas for these 2 species within the study area may indicate possible niche differentiations. The high omission rate for loggerheads indicates our samples likely underrepresent the population and illustrates the challenges in predicting suitable foraging extents for species that make dynamic movements and have greater individual variability.

2021 ◽  
Vol 9 (8) ◽  
pp. 793
Author(s):  
Abigail Uribe-Martínez ◽  
María de los Angeles Liceaga-Correa ◽  
Eduardo Cuevas

Marine turtles are globally endangered species that spend more than 95% of their life cycle in in-water habitats. Nevertheless, most of the conservation, recovery and research efforts have targeted the on-land habitats, due to their easier access, where adult females lay their eggs. Targeting the large knowledge gaps on the in-water critical habitats of turtles, particularly in the Large Marine Ecosystem Gulf of Mexico, is crucial for their conservation and recovery in the long term. We used satellite telemetry to track 85 nesting females from their beaches after they nested to identify their feeding and residency habitats, their migratory corridors and to describe the context for those areas. We delimited major migratory corridors in the southern Gulf of Mexico and West Caribbean and described physical features of internesting and feeding home ranges located mainly around the Yucatan Peninsula and Veracruz, Mexico. We also contributed by describing general aggregation and movement patterns for the four marine turtle species in the Atlantic, expanding the knowledge of the studied species. Several tracked individuals emigrated from the Gulf of Mexico to as far as Nicaragua, Honduras, and the Bahamas. This information is critical for identifying gaps in marine protection and for deciphering the spatial connectivity in large ocean basins, and it provides an opportunity to assess potential impacts on marine turtle populations and their habitats.


Oryx ◽  
2018 ◽  
Vol 53 (4) ◽  
pp. 752-756 ◽  
Author(s):  
Cristina Mata ◽  
Nicolás Fuentes-Allende ◽  
Juan E. Malo ◽  
André Vielma ◽  
Benito A. González

AbstractProtected areas help to decrease human impacts on threatened mammals but do not always include species’ core habitats. Here we focus on the Vulnerable taruka Hippocamelus antisensis near the Atacama Desert, Chile, a population that is mainly threatened by interactions with local human communities. We develop a species distribution model for taruka and assess the contribution of protected areas to safeguarding its preferred habitat. From sightings (collected during 2004–2015), absence records (collected in 2014), and environmental variables, we determined that taruka habitat is scarce, highly fragmented and limited to humid areas. Only 7.7–11.2% of the taruka's core habitat is under protection. We recommend the establishment of a protected area in the south of Arica-Parinacota district, an area without settlements that lies within the taruka's core habitat, along with educational programmes, fencing of crops, and inclusion of communities in decision-making in areas where farmer–taruka interactions are negative.


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.


Author(s):  
S. S. Thakuri ◽  
P. Shrestha ◽  
M. Deuba ◽  
P. Shah ◽  
O. P. Bhandari ◽  
...  

Abstract. Invasive Alien Plant Species are spreading outside of their natural geographic range. Water hyacinth (Eichhornia crassipes) is one of the most widely and rapidly spreading invasive species throughout the tropical and subtropical regions of Nepal. In the last decade, water hyacinth has become a chronic problem in many major lakes of Nepal which have affected the habitat aquatic plants and animals. Our study focuses on potential habitat modeling of Water hyacinth over the major lakes of Nepal using Maxent algorithm. Primary data used for modeling were 19 bioclimatic variables and Shuttle Radar Topography Model (SRTM) Digital Elevation Model (DEM). After preparation of the species distribution model, major lakes of Nepal were overlaid over the model to prepare potential invasive map. The performance and accuracy of potential habitat distribution model was evaluated using parameter Area under the Receiver Operating Characteristic Curve (AUC) which was within the range of 0.9–1. Validation of the model was done for the year 2015 with precision and recall, overall accuracy and F-measure and its values are 93% and 85%, 87% and 89% respectively. The model prepared for 2030 and 2050 shows the most suitable habitat for water hyacinth is in province 2 of Nepal and the moderately suitable habitat for this species is plain area of Province 4, 7 and 5. Similarly, the area of potential habitat has been increasing from current scenario to 2030 and 2050. From the potential invasion map, it can be observed that lakes in the Terai and Churey regions have the high risk of invasion of water hyacinth.


Author(s):  
Balaguru Balakrishnan ◽  
Nagamurugan Nandakumar ◽  
Soosairaj Sebastin ◽  
Khaleel Ahamed Abdul Kareem

Conservation of the species in their native landscapes required understanding patterns of spatial distribution of species and their ecological connectivity through Species Distribution Models (SDM) by generation and integration of spatial data from different sources using Geographical Information System (GIS) tools. SDM is an ecological/spatial model which combines datasets and maps of occurrence of target species and their geographical and environmental variables by linking various algorithms together, that has been applied to either identify or predict the regions fulfilling the set conditions. This article is focused on comprehensive review of spatial data requirements, statistical algorithms and softwares used to generate the SDMs. This chapter also includes a case study predicting the suitable habitat distribution of Gnetum ula, an endemic and vulnerable plant species using maximum entropy (MaxEnt) species distribution model for species occurrences with inputs from environmental variables such as bioclimate and elevation.


2020 ◽  
Vol 15 (3) ◽  
pp. 557-572
Author(s):  
John Stuhler ◽  
Daniela Arenas-Viveros ◽  
Jorge Salazar-Bravo

The short-tailed chinchilla (Chinchilla chinchilla) is a species classified as endangered throughout its distribution and for which neither a conservation nor management plan exists. Ecological niche models (ENMs) allow detection of potential areas of occurrence for species that are rare and/or of conservation interest. Here, we built and evaluated a suite of ENMs that incorporated new records for the species in Bolivia and removed those whose veracity could not be confirmed to provide an updated estimate of the extent of suitable habitat for C. chinchilla. Following model selection based on partial ROC, omission rate, and AICc, we then projected our top models across the historical distribution of C. chinchilla to identify locations of potentially suitable habitat. An ensemble of top models highlighted suitable habitat in Argentina, Bolivia, Chile, and Peru, with values of probability of suitable habitat up to 0.72. Together, these results demonstrate that suitable habitat still exists across the historical range of this species, provide insight into the climatic niche of this species, and highlight areas across the four countries for which future surveys of wild populations may be worthwhile.


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.


Author(s):  
Houlang Duan ◽  
Xiubo Yu ◽  
Shaoxia Xia ◽  
Guangshuai Zhang

Natural wetland along the coasts of Yellow and Bohai seas provided key stopover sites for migratory waterbirds. However, these wetlands are facing land loss. Understanding how natural wetlands loss influence habitat is an important step for habitat management. Using species distribution model to report changes in area of suitable habitat, and the effects of natural wetland loss on habitat for 80 waterbird species attributed to four functional categories (shorebird, duck, heron, gull), between 2000 and 2015 in the Yellow and Bohai seas. Of 1794.8 km2 of coastal wetland lost to development between 2000 and 2015, most represented tidal flats converted into aquaculture and salt pan habitat, or for construction. Consequently, habitat for 73 of these 80 species has decreased in area over this time period. Generally, the proportional decline in habitat suitable for species of duck was less than it was shorebirds, herons and gulls. The proportional loss of tidal flat habitat that formerly represented suitable habitat for shorebirds, herons and gulls was also significantly higher than it was for ducks. Because more species of duck exploit aquaculture and salt pan habitat converted from tidal flats than do shorebird, heron and gull species, such conversion of tidal flats pose a greater threat to shorebirds, herons and gulls than they do to ducks. Preventing further reclamation of tidal flats and managing artificial wetlands are priorities for waterbirds conservation, especially for the species ducks.


Author(s):  
Xinyu Liu ◽  
Xiaolu Han ◽  
Zhiqiang Han

Species have shown their habital variations in responding to climate change, especially during the spring and summer spawning seasons. The species distribution model (SDM) is considered the most favorable tool to study the potential effects of climate change on species distribution. Therefore, we developed the ensemble SDM to predict the changes in species distribution of Portunus trituberculatus among different seasons in 2050 and 2100 under the climate scenarios RCP4.5 and RCP8.5. The results of SDM indicate that the distribution of this species will move northward and have obviouse seasonal variations. Meanwhile, the suitable habitat for the species will be significantly reduced in summer, with loses rates ranging from 45.23% (RCP4.5) to 88.26% (RCP.8.5) by 2100s. Habitat reduction will mainly occur in the East China Sea and southern part of the Yellow Sea, while there will be a small increase in the northern Bohai Sea. These findings will be important to manage the ecosystem and fishery, provide an information forecast of this species in the future, and maintain species diversity if the seawater temperature rises.


Author(s):  
Christine C. Hass ◽  
Jerry W. Dragoo

Ecological niches of three species of skunks (Mephitidae: Conepatus leuconotus, Mephitis mephitis, M. macroura) in and near their overlap zone in the American Southwest were studied to determine if competition may be limiting distribution of these species. A species distribution model developed in MaxEnt was used to identify suitable habitat for each species, from which contact zones for each species pair were identified. Principal components derived from habitat and climate variables inside and outside of contact zones for each species, and between species pairs within the contact zone were then compared. Species differed in environmental space inside and outside of contact zones, but species pairs did not differ within contact zones, indicating no evidence of competitive exclusion, and possible niche convergence at a broad spatial scale


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