Spatiotemporal occurrence of Mishmi takin Budorcas taxicolor in Dulongjiang Region, southwestern China

Mammalia ◽  
2020 ◽  
Vol 84 (6) ◽  
pp. 513-519
Author(s):  
Xueyou Li ◽  
Cheng Huang ◽  
Xuelong Jiang
Keyword(s):  
Habitat Management ◽  
Species Distribution Model ◽  
Activity Patterns ◽  
Monitoring Program ◽  
Habitat Characteristics ◽  
Distribution Model ◽  
Mountain Areas ◽  
Circular Distribution ◽  
Presence Data ◽  
Budorcas Taxicolor

AbstractHere, we assessed the spatiotemporal distribution of the poorly studied Mishmi takin Budorcas taxicolor to gain a preliminary understanding of the spatiotemporal ecology of the species. We used presence data from line transects and camera-trap surveys combined with a presence-only species distribution model to identify the key factors relevant to takin distribution. Distance to residential site was the main contributing factor to the model predicting habitat suitability for takin. Mishmi takin appeared to prefer habitats far away from residential locations. Our predicted suitable habitats for takin were highly fragmented and were constrained in narrow ranges of remote mountain areas. A circular distribution curve fitted to camera events indicated that grouped takin were more active during the day and less active at night compared to solitary takin. Differences in activity patterns between takin in groups and solitaries might relate to sexual segregation and calve attendance. Our information on the distribution and habitat characteristics of the species will assist habitat management and our prediction map could guide future field surveys for locating a long-term monitoring program.

scholarly journals Waterbird habitat loss fringing the Yellow and Bohai seas along the East Asian--Australasian migratory flyway

2021 ◽  
Author(s):  
Houlang Duan ◽  
Xiubo Yu ◽  
Shaoxia Xia ◽  
Guangshuai Zhang
Keyword(s):  
Habitat Management ◽  
Coastal Wetland ◽  
Species Distribution Model ◽  
Tidal Flats ◽  
Distribution Model ◽  
Suitable Habitat ◽  
Natural Wetland ◽  
Artificial Wetlands ◽  
Waterbird Species ◽  
Salt Pan

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.

scholarly journals Defining Conservation Requirements for the Suweon Treefrog (Dryophytes suweonensis) Using Species Distribution Models

Diversity ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 69
Author(s):  
Il-Kook Park ◽  
Daesik Park ◽  
Amaël Borzée
Keyword(s):  
Habitat Loss ◽  
Species Distribution ◽  
Species Distribution Model ◽  
Rice Paddy ◽  
Habitat Characteristics ◽  
Distribution Model ◽  
Suitable Habitat ◽  
Rice Paddies ◽  
Agricultural Wetlands ◽  
North East

Numerous amphibian species are declining because of habitat loss and fragmentation due to urbanization of landscapes and the construction of roads. This is a mounting threat to species restricted to habitats close to urban areas, such as agricultural wetlands in North East Asia. The Suweon treefrog (Dryophytes suweonensis) falls into the list of species threatened with habitat loss and most populations are under threat of extirpation. Over the last decades, sub-populations have become increasingly disconnected and specifically the density of paved roads has increased around the only site connecting northern and southern Seoul populations. We surveyed this locality in Hojobeol, Siheung, Republic of Korea in 2012, 2015 and 2019 to first confirm the decline in the number of sites where D. suweonensis was present. The second objective was to analyze the habitat characteristics and determine the remaining suitable habitat for D. suweonensis through a species distribution model following the maximum entropy method. Our results show that rice paddy cover and distance from the paved road are the most important factor defining suitable habitat for D. suweonensis. At this locality, uninterrupted rice paddies are a suitable habitat for the species when reaching at least 0.19 km2, with an average distance of 138 ± 93 m2 from the roads. We link the decrease in the number of sites where D. suweonensis is present with the decrease in rice paddy cover, generally replaced by localized infrastructures, greenhouses and habitat fragmentation. Rice paddies should remain connected over a large area for the protection of the remaining populations. In addition, habitat requirements should be integrated in the requisites to designate protected areas.

scholarly journals Using a Species Distribution Approach to Model Historic Camas (Camassia quamash) in Southern Idaho and Implications for Foraging in the Late Archaic

2020 ◽  
Author(s):  
Royce Johnson
Keyword(s):  
Pacific Northwest ◽  
Species Distribution ◽  
Species Distribution Model ◽  
Diet Breadth ◽  
Habitat Characteristics ◽  
Distribution Model ◽  
Late Archaic ◽  
Human Diet ◽  
The Pacific ◽  
Suitable Habitats

Camas (Camassia quamash) is well documented as a traditional native food source throughout the Northwestern United States and Canada. A better understanding of the historic distribution of camas in Idaho would help to distinguish root foraging in this region from the Pacific Northwest. Modern grazing, development, climate change, and other factors have decimated native camas in this region. This study uses a species distribution model (MaxEnt) to provide a well-informed geospatial projection of the historic distribution and habitat characteristics of camas in Southern Idaho. Understanding the most significant landscape and climate characteristics for camas allows us to estimate suitable habitats, and therefore the potential influence of camas on human diet breadth and mobility in the Late Archaic.

scholarly journals A Robust Prediction Model for Species Distribution Using Bagging Ensembles with Deep Neural Networks

2021 ◽  
Vol 13 (8) ◽  
pp. 1495
Author(s):  
Jehyeok Rew ◽  
Yongjang Cho ◽  
Eenjun Hwang
Keyword(s):  
Neural Networks ◽  
Species Distribution ◽  
Best Practice ◽  
Deep Neural Networks ◽  
Species Distribution Models ◽  
Species Distribution Model ◽  
Environmental Data ◽  
Distribution Model ◽  
Distribution Models ◽  
Robust Prediction

Species distribution models have been used for various purposes, such as conserving species, discovering potential habitats, and obtaining evolutionary insights by predicting species occurrence. Many statistical and machine-learning-based approaches have been proposed to construct effective species distribution models, but with limited success due to spatial biases in presences and imbalanced presence-absences. We propose a novel species distribution model to address these problems based on bootstrap aggregating (bagging) ensembles of deep neural networks (DNNs). We first generate bootstraps considering presence-absence data on spatial balance to alleviate the bias problem. Then we construct DNNs using environmental data from presence and absence locations, and finally combine these into an ensemble model using three voting methods to improve prediction accuracy. Extensive experiments verified the proposed model’s effectiveness for species in South Korea using crowdsourced observations that have spatial biases. The proposed model achieved more accurate and robust prediction results than the current best practice models.

scholarly journals A Bioclimate-Based Maximum Entropy Model for Comperiella calauanica Barrion, Almarinez and Amalin (Hymenoptera: Encyrtidae) in the Philippines

Insects ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 26
Author(s):  
Billy Joel M. Almarinez ◽  
Mary Jane A. Fadri ◽  
Richard Lasina ◽  
Mary Angelique A. Tavera ◽  
Thaddeus M. Carvajal ◽  
...  
Keyword(s):  
Maximum Entropy ◽  
Habitat Suitability ◽  
Species Distribution Model ◽  
Biological Control Agent ◽  
The Philippines ◽  
Distribution Model ◽  
Field Surveys ◽  
Probability Of Occurrence ◽  
Precipitation Seasonality ◽  
Bioclimatic Variables

Comperiella calauanica is a host-specific endoparasitoid and effective biological control agent of the diaspidid Aspidiotus rigidus, whose outbreak from 2010 to 2015 severely threatened the coconut industry in the Philippines. Using the maximum entropy (Maxent) algorithm, we developed a species distribution model (SDM) for C. calauanica based on 19 bioclimatic variables, using occurrence data obtained mostly from field surveys conducted in A. rigidus-infested areas in Luzon Island from 2014 to 2016. The calculated the area under the ROC curve (AUC) values for the model were very high (0.966, standard deviation = 0.005), indicating the model’s high predictive power. Precipitation seasonality was found to have the highest relative contribution to model development. Response curves produced by Maxent suggested the positive influence of mean temperature of the driest quarter, and negative influence of precipitation of the driest and coldest quarters on habitat suitability. Given that C. calauanica has been found to always occur with A. rigidus in Luzon Island due to high host-specificity, the SDM for the parasitoid may also be considered and used as a predictive model for its host. This was confirmed through field surveys conducted between late 2016 and early 2018, which found and confirmed the occurrence of A. rigidus in three areas predicted by the SDM to have moderate to high habitat suitability or probability of occurrence of C. calauanica: Zamboanga City in Mindanao; Isabela City in Basilan Island; and Tablas Island in Romblon. This validation in the field demonstrated the utility of the bioclimate-based SDM for C. calauanica in predicting habitat suitability or probability of occurrence of A. rigidus in the Philippines.

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