line transects
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2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Walfrido Moraes Tomas ◽  
Christian Niel Berlinck ◽  
Rafael Morais Chiaravalloti ◽  
Gabriel Paganini Faggioni ◽  
Christine Strüssmann ◽  
...  

AbstractAnthropogenic factors have significantly influenced the frequency, duration, and intensity of meteorological drought in many regions of the globe, and the increased frequency of wildfires is among the most visible consequences of human-induced climate change. Despite the fire role in determining biodiversity outcomes in different ecosystems, wildfires can cause negative impacts on wildlife. We conducted ground surveys along line transects to estimate the first-order impact of the 2020 wildfires on vertebrates in the Pantanal wetland, Brazil. We adopted the distance sampling technique to estimate the densities and the number of dead vertebrates in the 39,030 square kilometers affected by fire. Our estimates indicate that at least 16.952 million vertebrates were killed immediately by the fires in the Pantanal, demonstrating the impact of such an event in wet savanna ecosystems. The Pantanal case also reminds us that the cumulative impact of widespread burning would be catastrophic, as fire recurrence may lead to the impoverishment of ecosystems and the disruption of their functioning. To overcome this unsustainable scenario, it is necessary to establish proper biomass fuel management to avoid cumulative impacts caused by fire over biodiversity and ecosystem services.


2021 ◽  
Vol 25 (8) ◽  
pp. 1387-1391
Author(s):  
M.J. Francis ◽  
A.A. Chaskda ◽  
A. Ombugadu ◽  
S.D. Karau ◽  
O.C. Mathias ◽  
...  

The knowledge on the factors influencing habitat selection is of uttermost importance because it guides the development of conservation action plan for species. Till date, there is no baseline study on the genus Euplectes in Northern Nigeria thus, an attempt to investigate the habitat preference of the genus was carried out in Amurum Forest Reserve and the nonprotected habitats of Fobur. Line transects of 200m were randomly laid across the study sites. The abundance of Bishop species was highest in farmland compared to grassland and rocky outcrop. Therefore, the number of the species was significantly different between habitats (F2, 573 = 5.454, P = 0.0015). There was a significant relationship between flock size and number of seeds across habitat types. Number of individual birds increased with increase in seed number (F1, 57 = 21687.786, P < 0.001). With the exception of grass height, there was a highly significant difference in relation to vegetation variables taken between plots where Bishop species were sighted and the random points where they were not seen (P < 0.001). The finding suggests that farmlands should be integrated into conservation plan in the nonprotected area based on the high population of the genus recorded.


2021 ◽  
Vol 13 (2) ◽  
pp. 1
Author(s):  
Amir Hossen ◽  
Eivin Røskaft

We examined the relationship between the presence or absence of elephants in patches of land and the most common ecological factors, such as fodder species, water bodies, resting places, elephant movement trails, and soil types, across ten transect sites in the Teknaf Wildlife Sanctuary (TWS), Bangladesh. By ground-truthing 360 line transects and 1080 quadrate blocks, we recorded a total of 184 fodder species, including 71 monocotyledons, 58 dicotyledons, and 55 domesticated plant species. Three categories of domesticated fodder species were recorded that consisted of 13 cultivated crops, 24 vegetables, and 18 homestead garden plants. We also applied dung-pile dissection techniques to a total of 250 dung piles between August 2018 and July 2019. Highly statistically significant differences among the abundances of different fodder species and presence of elephants were found across different transect sites. The average fodder species density was found to be 3.44 plant species per site per km2, while the elephant density was 0.63 individuals per site per km2. A significant strong correlation was found between fodder species density and the number of elephants among the transect sites (P = 0.02). The numbers of ground-recorded fodder species were higher than those found in dung piles. The presence of elephants across transect sites was influenced not only by fodder species but also by other ecological factors, such as water bodies, resting places, movement trails, and soil types.


2021 ◽  
pp. 1-11
Author(s):  
TIWA ONG-IN ◽  
TOMMASO SAVINI

Summary Habitat degradation due to hydropower development within protected areas has a marked negative effect on resident wildlife species. However, efforts to develop appropriate conservation and management plans are hampered by a general lack of quantitative information and a poor understanding of relevant ecological constraints. Great Argus Argusianus argus, a large galliform species sensitive to habitat degradation, can reflect the impacts of the Chiew Larn reservoir in southern Thailand on local wildlife. Great Argus abundance in the remaining lowland areas of Khlong Saeng Wildlife Sanctuary (KSWS) was estimated using line transects along the Chiew Larn reservoir edges and in the forest interior between February and April 2017. The population estimate for KSWS was 108 individuals (95% CI: 41–272) based on the sampled area of 18.06 km2, with a density estimate of 5.9 calling males/km2. The abundance increased with increased distance from the reservoir shoreline, which might be related to the high level of direct and indirect human disturbance close to the hydropower reservoir.


2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Hirpasa Teressa ◽  
Hailu Minale ◽  
Solomon Birie ◽  
Yismaw Alemayehu

Gelada (Theropithecus gelada) is the only surviving primate of the genus Theropithecus that is endemic to Ethiopia. It adapted to live in afroalpine and subafroalpine ecosystems of the Ethiopian alpine. Although it is at risk of habitat loss due to agricultural expansion and deforestation, gelada has been classified as a least concern by the IUCN. Gelada has great importance as it represents the Ethiopian national treasure which brings tourists to the country. However, no proper gelada census has been carried out in and around Mount Guna (Mt. Guna). Therefore, the current study aimed to provide an accurate count of gelada individuals living in the study area. Total count along line transects was carried out from January 1–May 30, 2018, to estimate the population of gelada. According to the current result, gelada individuals counted from the entire sites of Mt. Guna were estimated to be 56. Forty-two gelada individuals were counted from outside the protected area, while 14 of them were from the protected area. There was a significant difference between gelada individuals counted from inside and outside the protected areas (P = 0.047). The ratio of age-sex of geladas also computed to be adult males: adult females: subadult males: subadult females: immature is 1 : 3.12 : 0.88 : 1.25 : 0.75 for the total population. Furthermore, five groups of geladas were observed outside the Mt. Guna community conservation area at three sites, while only one group of geladas was identified from the protected area. Based on the current result, we recommend further research to study the population trend, fertility problems, and conservation mechanisms of geladas living within the agricultural land and human-gelada conflicts around Mt. Guna.


Oryx ◽  
2021 ◽  
pp. 1-7
Author(s):  
Chenchen Ding ◽  
Jie Liu ◽  
Chunwang Li ◽  
Zhigang Jiang

Abstract The hog deer Axis porcinus formerly occurred in south-west China but has not been recorded there since 1965. To investigate the current status of the species in China, we conducted interviews, and transect and camera-trap surveys during October 2018–June 2020 to search for signs of hog deer across its historical range in the country. We interviewed 50 local inhabitants and surveyed 14 line transects in four counties of Lincang City, Yunnan Province. The camera traps were deployed in Nangunhe Nature Reserve (39.4 km of transects, 82 camera stations, 15,120 camera days) and Daxueshan Nature Reserve (41.1 km of transects, 68 camera stations, 13,554 camera days). We found no hog deer tracks and no hog deer were trapped by cameras. The floodplain grasslands preferred by hog deer along Nanting River have been transformed into agriculture plantations and human settlements. Our findings suggest that hog deer may have been extirpated from China, most likely as a result of habitat loss and overhunting. The conservation priorities for this species in China are the establishment of a protected area in the Nanting River watershed, restoration of habitat and reintroduction of individuals from range countries.


2021 ◽  
Vol 21 (3) ◽  
pp. 160-167
Author(s):  
ITSNATANI SALMA ◽  
ZURIANA SIREGAR ◽  
ALIA RIZKI ◽  
SUWARNO SUWARNO

Butterflies are insects that live cosmopolitan. Some butterflies in tropical forests look for food sources from sucking the juice of ripe fruits that have fallen on the forest floor. Fruit-feeding butterflies can adapt in finding food sources, selecting and sucking food effectively. Fruit contains varying concentrations of sugar and nitrogen. The existence of fruit-feeding butterflies in tropical rain forests is influenced by the availability and quality of food sources as well as other supporting factors such as temperature, humidity, and light intensity. The purpose of this study was to identify fruit-feeding butterflies and their preferences for banana and pineapple baits in the Soraya Research Station Area, Leuser Ecosystem, Aceh, Indonesia from September to November 2020. Six forest trail locations were selected as trap locations. A total of 360 cylindrical gauze baited traps (80 cm high and 35 cm diameter) were installed on six trails/line transects. Baited traps were set at three different heights, that is at the understorey level (± 0-2 m), midstorey level (± 5-6 m), and overstorey level (± 10-11 m) with a distance of ± 5-10 m. The distance between location points is ± 250 m. The fruit baits used in this trap were ripe bananas and pineapples. The results obtained were 37 species with 176 individuals trapped on banana bait and 50 species with 183 individuals on pineapple bait. However, the results of the t-test using the Man-Whitney test showed no significant difference between the banana and pineapple bait used.


Diversity ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 483
Author(s):  
Dudi Nandika ◽  
Dwi Agustina ◽  
Robert Heinsohn ◽  
George Olah

Indonesia has been identified as the highest priority country for parrot conservation based on the number of species, endemics, and threats (trapping and smuggling). It is crucial to understand the current population status of parrots in the wild in relation to the illegal wildlife trade but the ecology and population dynamics of most parrot species in this region remain poorly understood. We conducted a parrot survey around an area of high biodiversity in the Manusela National Park, in Seram Island, Indonesia. We used a combination of fixed-radius point counts and fixed-width line transects to count multiple species of parrots. We recorded nearly 530 wild parrots from 10 species in and around Manusela National Park. The dominant parrot species were Eos bornea, Trichoglosus haematodus, and Geoffroyus geoffroyi. We applied the Savage selectivity index to evaluate poaching of parrot species in proportion to their abundance and which species had higher than expected poaching pressure. This study has important implications for the conservation status of endemic parrots (Cacatua moluccensis, Lorius domicella, and Eos semilarvata) and shows that parrots in the Manusela NP are largely threatened by poaching.


2021 ◽  
Author(s):  
Walfrido Moraes Tomas ◽  
Christian Niel Berlinck ◽  
Rafael Morais Chiaravalloti ◽  
Gabriel Paganini Faggioni ◽  
Christine Strussmann ◽  
...  

Abstract Anthropogenic factors have significantly influenced the frequency, duration, and intensity of meteorological drought in many regions of the globe, and the increased frequency of wildfires is among the most visible consequences of human-induced climate change. Despite its role in determining biodiversity outcomes in different ecosystems, wildfires can cause negative impacts on wildlife. We conducted ground surveys along line transects to estimate the first-order impact of the 2020 wildfires on vertebrates in the Pantanal wetland, Brazil. We adopted the distance sampling technique to estimate the densities and the number of dead vertebrates in the 39,030 square kilometers affected by fire. Our estimates indicate that at least 16.952 million vertebrates were killed immediately by the fires in the Pantanal, demonstrating the impact of such an event in wet savanna ecosystems. The Pantanal case also reminds us that the cumulative impact of widespread burning would be catastrophic, as fire recurrence may lead to the impoverishment of ecosystems and the disruption of their functioning. To overcome this unsustainable scenario, it is necessary to establish proper biomass fuel management to avoid cumulative impacts caused by fire over biodiversity and ecosystem services.


2021 ◽  
Author(s):  
Suman Attiwilli ◽  
Nitin Ravikanthachari ◽  
Krushnamegh Kunte

Long-term monitoring programmes have revealed catastrophic population declines that are contributing to biodiversity loss. These discoveries and the underlying programmes have been possible because of standardised methods of counting butterflies. Butterflies have been monitored using modified line transects, known in butterfly monitoring schemes as Pollard walks. However, line transects are not feasible in many tropical and mountainous habitats. To tackle this problem, we devised time-constrained (30-min) counts and compared butterfly diversity as estimated through this method with that estimated through line transects (500 m, 10 min) in three tropical habitats in India (evergreen forest, dry deciduous forest and an urban woodland). We tested the efficacy of the two methods to sample species richness and abundance, as well as numbers of rare, endemic and specialist butterflies. We observed greater species richness, and more species of habitat specialists and endemics per sample in time-constrained counts when compared with line transects in evergreen forest, but not in the other two habitats. Thus, time-constrained counts were more efficient at detecting species than line transects in the species-rich evergreen habitat. Apart from this difference, the two sampling methods captured similar levels of species richness and other measures of diversity. Time-constrained counts may thus be viewed as a feasible alternative to line transects to carry out butterfly surveys in tropical and mountainous landscapes. This method is particularly suited for biodiversity assessments and mapping involving citizen science initiatives, which has considerable potential in populous and tech-ready countries such as India.


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