Population Estimates of Hubbard’s Sportive Lemur (Lepilemur hubbardorum) at Zombitse-Vohibasia National Park, Madagascar

2021 ◽  
pp. 1-9
Author(s):  
Luke D. Martin ◽  
Amanda K. Rowe ◽  
Eva S. Nomenjanahary ◽  
Serenity K. Montaño ◽  
Patricia C. Wright ◽  
...  
Keyword(s):  
National Park ◽  
Primate Species ◽  
Population Estimates ◽  
Conservation Priorities ◽  
Line Transect ◽  
Population Declines ◽  
Sampling Area ◽  
Abundance Estimate ◽  
Protected Forests ◽  
Sportive Lemur

Estimates of population size are fundamental to setting conservation priorities for threatened primate species. Many taxa in the lemur genus <i>Lepilemur</i> remain understudied, and basic population statistics are often dated, incomplete, or absent. Hubbard’s sportive lemur (<i>Lepilemur hubbardorum</i>) is known only from the Zombitse-Vohibasia National Park region in southwestern Madagascar. It is listed as Endangered by the IUCN owing to its fragmented, declining habitat and limited geographic range. However, this classification has not been confirmed through systematic population estimates. To address this issue, we undertook line transect surveys in the Zombitse parcel of the National Park. We applied geospatial analyses and data to quantify forest area as a proxy for <i>L</i>. <i>hubbardorum</i>habitat. We recorded a total of 234 <i>L</i>.<i> hubbardorum</i> sightings over 18 survey nights, representing 47.2 km of survey effort. Our surveys revealed population densities of 145.6 <i>L</i>.<i> hubbardorum</i> individuals per km<sup>2</sup> (95% CI: 97.2–218.1), for an extrapolated abundance estimate of ca. 16,500–18,000 <i>L</i>. <i>hubbardorum</i> individuals across the protected forests of the Zombitse parcel. This abundance estimate should be considered provisional, however, because our restricted sampling area did not include the more remote regions of the National Park where habitat disturbance and hunting practices have likely contributed to localized population declines.

Application of distance sampling to estimate population densities of large herbivores in Kruger National Park

2008 ◽  
Vol 35 (4) ◽  
pp. 371 ◽  
Author(s):  
J. M. Kruger ◽  
B. K. Reilly ◽  
I. J. Whyte
Keyword(s):  
National Park ◽  
Distance Sampling ◽  
Kruger National Park ◽  
Population Trends ◽  
Population Estimates ◽  
Line Transect ◽  
Large Herbivores ◽  
Sampling Intensity ◽  
Coefficients Of Variation ◽  
White Rhinoceros

Aerial surveys have been used in the Kruger National Park, South Africa, to count large ungulates since the late 1970s. After 1998, aerial line-transect sampling using fixed-wing aircraft and Distance analyses replaced the ‘total’ counting method. This paper investigates these methods and three sampling intensities for estimating the densities of nine large ungulate species in Kruger National Park. Estimates suitable for the detection of population trends and making management decisions were decided by examination of coefficients of variation (set <20%, a priori). Despite the likely violation of some key assumptions of Distance sampling methods, analyses gave population estimates with adequate coefficients of variation for monitoring trends in impala, giraffe, zebra, kudu, white rhinoceros, and elephant bull populations. Significant improvements in precision were obtained at higher sampling intensities for kudu, giraffe, bull elephants and white rhinoceros, but these species already had sufficiently precise population estimates for the detection of trends at the lowest sampling intensity (15%). The estimates for warthog, wildebeest and waterbuck populations were, however, insufficiently precise for assessing population trends. Increasing sampling intensity to 22% and higher did not significantly increase the precision of the Distance estimates for these species. Shortcomings in interpretation of the data caused by violations of critical assumptions of analyses are identified and discussed.

scholarly journals Detection of Gopher Tortoise Burrows Before and After a Prescribed Fire: Implications for Surveys

2018 ◽  
Vol 10 (1) ◽  
pp. 62-68 ◽  
Author(s):  
Jennifer M. Howze ◽  
Lora L. Smith
Keyword(s):  
Habitat Structure ◽  
Survey Methodology ◽  
Distance Sampling ◽  
Population Estimates ◽  
Line Transect ◽  
Past Century ◽  
Prescribed Burn ◽  
Gopher Tortoise ◽  
Imperfect Detection ◽  
Abundance Estimate

Abstract Gopher tortoise Gopherus polyphemus populations have declined by as much as 80% over the past century, primarily as a result of habitat loss. In 2006, the eastern population of the gopher tortoise was petitioned for federal listing as threatened. In response, a Candidate Conservation Agreement was developed for the gopher tortoise. A Candidate Conservation Agreement is a voluntary agreement between the U.S. Fish and Wildlife Service and other interested parties to address the conservation needs of a species before it becomes federally listed and to enact measures to preclude the need to list the species. The gopher tortoise Candidate Conservation Agreement identified an assessment of the status of populations on protected lands as a priority and line transect distance sampling (LTDS) was adopted as the standardized survey methodology. Surveys with LTDS rely on detection of gopher tortoise burrows because tortoises are fossorial. However, gopher tortoise burrows vary greatly in size and small burrows of juveniles are rarely detected. Although LTDS is statistically robust and allows for imperfect detection, few studies have examined how detection varies with tortoise burrow size and whether habitat structure may influence detection of gopher tortoise burrows. Both factors could affect the accuracy of population estimates using LTDS and interpretation of demographic parameters needed for the Candidate Conservation Agreement. Therefore, we conducted surveys for burrows using LTDS before (28 March–13 April 2016) and after (9–18 May 2016) a prescribed burn, which reduced vegetation cover. We detected significantly more burrows (P &lt; 0.001, n = 651) of all sizes after the burn, and the burrow abundance estimate was 64% higher postburn. Our study showed that conducting gopher tortoise surveys after a prescribed burn increased detections and provided a more accurate population estimate. We therefore recommend conducting surveys immediately after a burn. However, varying burn cycles on large sites may make it difficult to survey following a prescribed burn and because the effects of a burn on habitat structure may vary within a site, methods to account for variation in detection due to habitat structure are needed. Population estimates for gopher tortoises using LTDS that do not account for variation in detection due to habitat structure likely underestimate population size.

scholarly journals Conservation Status and Habitat Preferences of Common Warthog (Phacochoerus Africanus) in Old Oyo National Park, Nigeria

2021 ◽  
Vol 25 (1) ◽  
pp. 87-92
Author(s):  
A.J. Adeola ◽  
A.I. Adeyemo ◽  
B.N. Ejidike ◽  
O.E. Olaniyi ◽  
O.A. Akande ◽  
...  
Keyword(s):  
Habitat Preference ◽  
National Park ◽  
Conservation Status ◽  
Habitat Preferences ◽  
Dry Season ◽  
Encounter Rate ◽  
Line Transect ◽  
Wet Season ◽  
Abundance Estimate ◽  
The Mean

This study assessed the conservation status and habitat preference of Common warthog in Old Oyo National Park, Nigeria using direct sighting and line transect method. The abundance estimate and encounter rate of common Warthog in the study area from 2018-2019 showed that year 2018 recorded 213 individuals at an encounter rate of 0.38/km while year 2019 recorded 184 individuals at an encounter rate of 0.32/km while the mean abundance estimate of common Warthog are 4.65±0.64 and 1.71±0.48 which represents 156 and 58 individuals at encounter rate of 0.55/km and 0.20/km in the wet season and dry season of year 2018 compared to year 2019 with average abundance estimate value of 4.00±0.85 and 1.41±0.61 which represents 135 and 48 individuals at an encounter rate of 0.47/km and 0.17/km for wet and dry season respectively. The mean age structure and sex ratio of the observed warthog population during dry and wet seasons revealed that juveniles had highest mean of age structures among the populations observed across the seasons. The habitat preference of common warthog revealed that they are mostly found in mixed woodland and open savanna with 112 observation and the lowest was recorded in the outcrop vegetation and open savanna with 21 individuals.in the wet season. During the dry season, mixed woodland/open savanna and Riparian grassland had the highest sightings of 45 and 33 individuals each. The outcrop vegetation/open savanna had the lowest observation of 1 individuals only. The study also recommends that more aspect of the ecology of the animal should be studied in details and emphasis should be placed on the habitat requirements. Keywords: Conservation, Estimate, Status, Warthog

Population structure, density and biomass of large herbivores in the tropical forests of Nagarahole, India

1992 ◽  
Vol 8 (01) ◽  
pp. 21-35 ◽  
Author(s):  
K. Ullas Karanth ◽  
Melvin E. Sunquist
Keyword(s):  
Population Structure ◽  
Tropical Forests ◽  
Primate Species ◽  
Line Transect ◽  
Large Herbivore ◽  
Large Herbivores ◽  
Transect Sampling ◽  
Structure Density ◽  
Density And Biomass ◽  
Turn Over

ABSTRACTWe studied the population structure, density and biomass of seven ungulate and two primate species in the tropical forests of Nagarahole, southern India, using line transect sampling and roadside/platform counts, during 1986–87. The estimated ecological densities of large herbivore species in the study area are: 4.2 muntjac km−2, 50.6 chital km−2, 5.5 sambar km−2, 0.8 four-horned antelope km−2, 9.6 gaur km−2, 4.2 wild pig km−2, 3.3 elephant km−2, 23.8 hanuman langur km−2and 0.6 bonnet macaque km−2. Most ungulates have female-biased adult sex ratios. Among common ungulate species, yearlings and young of the year comprise about a third of the population, suggesting relatively high turn-over rates. Three species (muntjac, sambar and four-horned antelope) are solitary, while others form groups. The study area supports a wild herbivore biomass density of 14,744 kg km−2. Among the three habitat types within the study area, biomass is lower in dry deciduous forests when compared with moist deciduous or teak plantation dominant forests. Using our results, we have examined the factors that may contribute towards maintenance of high ungulate biomass in tropical forests.

scholarly journals Managing Biodiversity: Impacts of Legal Protection in Mountain Forests of the Himalayas

Forests ◽  
2018 ◽  
Vol 9 (8) ◽  
pp. 476 ◽  
Author(s):  
Inger Måren ◽  
Lila Sharma
Keyword(s):  
Protected Areas ◽  
National Park ◽  
Flood Control ◽  
Forest Health ◽  
Legal Protection ◽  
Woody Species ◽  
Walking Distance ◽  
Participatory Management ◽  
Protected Forests ◽  
Agro Forestry

Legal protection has been used as means of conserving forests and associated biodiversity in many regions of the world since the eighteenth century. However, most forests in the global south, even those within protected areas, are influenced by human activities. Himalayan forests harbour much of the biodiversity of the region, maintain subsistence livelihoods, and provide regional and global ecosystem services like water regulation, flood control, and carbon sequestration. Yet few studies have quantitatively studied the impacts of legal protection on forest health and biodiversity. We assess woody biodiversity and forest health in relation to legal protection and biomass extraction in forests inside and outside Langtang National Park in Nepal (n = 180). We found more woody species in protected forests. Of the 69 woody species recorded, 47% occurred at both sites. Within protected forests, we found differences in forest health largely related to the intensity of biomass extraction expressed as walking distance to settlement. The closer the forest was to settlements, the heavier degradation it suffered, showing that within agro-forestry systems in the Himalayas, the resource-consumer distance is typically determining the intensity of biomass extraction. Our research brings forth the need to better address the drivers of resource extraction from protected areas in order to mitigate this degradation. It also brings forth the need to contribute to the development of appropriate participatory management programmes outside areas of formal protection in order to sustain both biodiversity and ecosystem service delivery from these forests for the future.

The importance of the Kruger National Park For bird conservation in the Republic of South Africa

Koedoe ◽  
1980 ◽  
Vol 23 (1) ◽  
Author(s):  
A. C Kemp
Keyword(s):  
South Africa ◽  
National Park ◽  
Kruger National Park ◽  
Tropical Species ◽  
Conservation Priorities ◽  
Bird Conservation ◽  
The Republic ◽  
Wetland Habitats

One hundred and two species of birds that are thought to be vulnerable in South Africa have been reported from or are likely to occur within the Kruger National Park. These species are considered in relation to their distribution and status in South Africa and the neigbouring countries. The following are suggested as conservation priorities for birds in the Park: 1. Re-establish the extinct Yellow-billed Oxpecker. 2. Investigate the suite of large carnivorous and scavenging birds that have declined over much of their range elsewhere in South Africa. 3. Investigate the species associated with riparian and wetland habitats in the Park. 4. Investigate the tropical species that are confined to the Park within South Africa.

scholarly journals Seasonal influence of snow conditions on Dall’s sheep productivity in Wrangell-St Elias National Park and Preserve

PLoS ONE ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. e0244787
Author(s):  
Christopher L. Cosgrove ◽  
Jeff Wells ◽  
Anne W. Nolin ◽  
Judy Putera ◽  
Laura R. Prugh
Keyword(s):  
Snow Depth ◽  
National Park ◽  
Meteorological Data ◽  
Multiple Regression Model ◽  
Snow Accumulation ◽  
Population Declines ◽  
Climate Conditions ◽  
Remote Cameras ◽  
Snow Conditions ◽  
Dall’S Sheep

Dall’s sheep (Ovis dalli dalli) are endemic to alpine areas of sub-Arctic and Arctic northwest America and are an ungulate species of high economic and cultural importance. Populations have historically experienced large fluctuations in size, and studies have linked population declines to decreased productivity as a consequence of late-spring snow cover. However, it is not known how the seasonality of snow accumulation and characteristics such as depth and density may affect Dall’s sheep productivity. We examined relationships between snow and climate conditions and summer lamb production in Wrangell-St Elias National Park and Preserve, Alaska over a 37-year study period. To produce covariates pertaining to the quality of the snowpack, a spatially-explicit snow evolution model was forced with meteorological data from a gridded climate re-analysis from 1980 to 2017 and calibrated with ground-based snow surveys and validated by snow depth data from remote cameras. The best calibrated model produced an RMSE of 0.08 m (bias 0.06 m) for snow depth compared to the remote camera data. Observed lamb-to-ewe ratios from 19 summers of survey data were regressed against seasonally aggregated modelled snow and climate properties from the preceding snow season. We found that a multiple regression model of fall snow depth and fall air temperature explained 41% of the variance in lamb-to-ewe ratios (R2 = .41, F(2,38) = 14.89, p<0.001), with decreased lamb production following deep snow conditions and colder fall temperatures. Our results suggest the early establishment and persistence of challenging snow conditions is more important than snow conditions immediately prior to and during lambing. These findings may help wildlife managers to better anticipate Dall’s sheep recruitment dynamics.

scholarly journals KEPADATAN POPULASI MAMALIA DARAT KARNIVORA DI CAMP LEAKEY KAWASAN TAMAN NASIONAL TANJUNG PUTING, KALIMANTAN TENGAH

Jurnal BIOMA ◽  
2017 ◽  
Vol 12 (2) ◽  
pp. 83
Author(s):  
Siwi Arthapati Mandiri ◽  
Paskal Sukandar ◽  
Yossa Istiadi
Keyword(s):  
Data Collection ◽  
Population Density ◽  
National Park ◽  
Line Transect ◽  
Line Transect Sampling ◽  
Clouded Leopard ◽  
Helarctos Malayanus ◽  
Transect Sampling ◽  
Palm Civet ◽  
Leopard Cat

Borneo has wide land that support high biodiversity. One of them is Tanjung Puting National Park (TPNP), which have biodiversity such as terrestrial mammalian carnivore. Carnivore has a role to maintain its ecosystems. But, there are no data for population density of terrestrial mammalian carnivore. The object of this research is to find out population density of terrestrial mammalian carnivore in Camp Leakey, TPNP, Central Borneo. This research accomplished in September-October 2015 in Camp Leakey. Using line-transect sampling. Data collection was accomplished at 18.00-24.00 Central Indonesian Time (WITA) on eight transects with three times replication by direct surveys and indirect surveys. This research has obtained five species, malayan sun bear (Helarctos malayanus), sunda clouded leopard (Neofelis diardi), leopard cat, and group of civet, like small-toothed palm civet (Arctogalidia trivirgata) and asian palm civet (Paradoxurus hermaphroditus). Population density of each species from the highest to the lowest is 13,5 Individual of leopard cat/km2, 9,84 Individual of malayan sun bears/km2, 4,31 Individual of sunda clouded leopard/km2, and 3,65 Individual of civet/km2. Malayan sun bears, sunda clouded leopards and civets prefer to be in land forest. Leopard cats prefers to be in transition forest.

scholarly journals Vegetation structure and floristic composition of tree species in the habitat of Scaphium macropodum in Gunung Leuser National Park, Sumatra, Indonesia

2020 ◽  
Vol 21 (7) ◽  
Author(s):  
ARIDA SUSILOWATI ◽  
DENI ELFIATI ◽  
HENTI HENDALSTUTI RACHMAT ◽  
KUSUMADEWI SRI YULITA ◽  
ADI NURUL HADI ◽  
...  
Keyword(s):  
Tree Species ◽  
Vegetation Structure ◽  
National Park ◽  
Diversity Index ◽  
Good Condition ◽  
Floristic Composition ◽  
Line Transect ◽  
Growth Stages ◽  
Limited Information ◽  
Wiener Diversity Index

Abstract. Susilowati A, Elfiati D, Rachmat HH, Yulita KS, Hadi AN, Kusuma YS, Batu SAL. 2020. Vegetation structure and floristic composition of tree species in the habitat of Scaphium macropodum in Gunung Leuser National Park, Sumatra, Indonesia. Biodiversitas 21: 3025-3033. Scaphium macropodum (Miq.) Beumee Ex K Heyne is a member of Malvaceae tree species and globally recognized as malva nut and locally known as ‘kembang semangkok’, ‘tempayang’, ‘merpayang’ or ‘kepayang’. The nut of S. macropodum has many benefits for medicinal purposes, yet destructive extraction of this tree species has led them to extinction. Among its natural distribution in Indonesia, North Sumatra Province, Indonesia is known as its original range, but there is limited information about the existence of this species. This study aimed to determine the vegetation structure of some tree species in the habitat of S. macropodum in Sikundur, Gunung Leuser National Park, Sumatra, Indonesia. Purposive sampling technique was employed by creating line transect at some forest areas where the population of S. macropodum is known to grow naturally. Four line transects with each transect consisting of five plots with nested plots within were established to record data at four growth stages, resulting in 80 plots in total. The results showed that the Important Value Index (IVI) of S. macropodum within the floristic community at the studied area was 21.98, 13.85, 27.30, and 39.60 for tree, pole, sapling, and seedlings stages, respectively. The Shannon-Wiener Diversity Index (H) were 3.80, 3.70, 3.06 and 2.45, Index of evenness (E) are 0.94, 0.92, 0.86, 0.77 and the Index of Richness (R) are 11.76, 10.73, 6.59, 4.10 for tree, pole, sapling, and seedlings stages. This result suggests that the natural population of S. macropodum in Sikundur forest was still in good condition at all stages from tree to seedling.

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