Gorilla Abundance Estimations within North-East Moukalaba-Doudou National Park, Gabon

2021 ◽  
pp. 1-9
Author(s):  
Nana Ismaila ◽  
Ulrich Maloueki
Keyword(s):  
National Park ◽  
Conservation Status ◽  
Mixed Forest ◽  
Habitat Type ◽  
Survey Method ◽  
Encounter Rate ◽  
Line Transect ◽  
Sampling Effort ◽  
North East ◽  
Minimal Convex

Accurate measures of animal population densities are essential to evaluate conservation status and implement action plans to ensure species survival. Gorilla numbers were assessed using the recce survey method within Moukalaba-Doudou National Park (MDNP) in Gabon using fresh nest counts of up to 1 week old. We walked 3,592 km within a 23.01-km<sup>2</sup> study site totalling a sampling effort of 297 days. Encounter rate was 0.12 fresh nests per kilometre, and gorilla density estimates generated by home range sizes (by minimal convex polygon) ranged between 1.14 and 1.48 gorillas/km<sup>2</sup>. Gorillas preferred mixed forest for nesting over other habitats (Cheason index value 1.31). Results showed that gorilla density values within the study area concurred with previous studies that used line transect methodologies. We conclude that the choice of sampling design is dependent on environmental conditions characterised by each habitat type and target species.

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

Corrigendum to: Distribution and relative abundance of forest duikers in Dassioko Sud Forest Reserve (coastal Côte d'Ivoire)

2018 ◽  
Vol 45 (2) ◽  
pp. 194
Author(s):  
K. A. Yao ◽  
E. A. Bitty ◽  
K. B. Kassé ◽  
Y. C. Kouakou ◽  
K. H. Yaokokoré-Beibro ◽  
...  
Keyword(s):  
Relative Abundance ◽  
Habitat Preferences ◽  
Habitat Type ◽  
Distribution Patterns ◽  
Encounter Rate ◽  
Line Transect ◽  
Habitat Types ◽  
Anthropogenic Pressures ◽  
Forest Reserve ◽  
Encounter Rates

Context Duikers play a vital role in maintaining forest ecosystems, as both seed dispersers and prey. In West Africa, duikers are also an important source of food and income; however, it is likely that some species are now being hunted at unsustainable levels. So as to contribute to duiker conservation, we used line-transect data and additional information on dung and track counts to estimate relative abundance and establish distribution patterns of forest duikers in Côte d'Ivoire's Dassioko Sud Forest Reserve (DSFR), a poorly known, remnant coastal rainforest. We also collected basic information on hunting pressure. Methods Forest duiker counts were made twice per month from July 2013 to March 2014 on six line transects of varying lengths (5.6–6.7km) and in different regions of the DSFR, representing different habitat types. The number of sightings per kilometre walked, defined as ‘encounter rate', was used to compute an index of relative abundance. We recorded all evidence of poachers and used these data to generate a poaching index (# poaching signs per kilometre) for different habitat types. Key results The DSFR has lost three of seven total forest duiker species and populations of the four remaining species are declining. Encounter rates were greatest for Philantomba maxwellii (0.46 indices km–1) and accounted for 68% of total encounters. Cephalophus niger, C. dorsalis and C. silvicultor were encountered at similar (0.07 indices km–1) but much lower rates. For all species, mean encounter rates were highest in degraded forest (0.38–0.73 indices km–1), followed by secondary (0.2–0.44 indices km–1) and primary (0.19–0.44 indices km–1) forest. Conclusions Of the four forest duiker species still present in the DSFR, the black, bay and yellow-backed duikers are the most affected by anthropogenic pressures. Duiker abundance in the DSFR varies with habitat type. This variation is apparently influenced by differences in forest structure, poaching pressure and proximity to villages. Implications The study provides baseline data for future managing of ungulate populations in the DSFR. We recommend that a biomonitoring study of duiker populations be initiated immediately to help determine population trends, investigate habitat preferences, and help curb illegal hunting activities in this important forest reserve.

scholarly journals Tentative list of endemic vascular plants of the Zeravshan Mts in Tajikistan: distribution, habitat preferences and conservation status of species

2010 ◽  
Vol 19 (1) ◽  
pp. 65-80 ◽  
Author(s):  
Arkadiusz Nowak ◽  
Marcin Nobis
Keyword(s):  
Vascular Plants ◽  
National Park ◽  
Conservation Status ◽  
Habitat Preferences ◽  
Habitat Type ◽  
Mean Value ◽  
Taxonomic Structure ◽  
Endemic Plants ◽  
Effective Protection ◽  
The Mean

Tentative list of endemic vascular plants of the Zeravshan Mts in Tajikistan: distribution, habitat preferences and conservation status of speciesBased on literature data and own fieldwork in the Zeravshan Mts in Tajikistan (Middle Asia), the taxonomic structure, distribution, habitat preferences as well as conservation status of a group of 86 species of vascular plants of endemic character are presented. The tentative list of exclusive endemic plants for the Zeravshan Mts was compiled. They belong to 25 families. The richest is the genusAstragaluswith 11 species followed byCousinia(8),Allium(5) andScutellaria(3). The study has shown that the eastern subregions of the range are richest in endemics, especially, the Mogien-Daria, Seven Lakes, Pastrud-Daria, Ksztut and Yagnob valleys and Kuli-Kalon Plateau. The endemics studied are stenochoric species with very small number of known locations, mainly between one and two. The mean value of the range of the studied endemics is ca. 1140 km2. The most numerous endemic groups have been recorded at altitudes of around 1,800-2,100 and 2,700-3000 m a. s. l. The habitats harboring the richest group of endemics are rock screes, alpine forests, steppes and semi-savannas, alpine meadows, solid rocks, xerothermophilous shrubs and pastures. Almost half of the endemics have narrow ecological amplitude occurring in only one habitat type. The most important threats to Tajik endemics are intensive grazing and erosion of soils, as well as denudation. Most vulnerable types of vegetation to the human impact are forest and scrub communities. For effective protection of endemics in the Zeravshan Mts, a national park and a net of nature reserves has to be funded.

Impact of habitat type on the conservation status of tamarind (Tamarindus indicaL.) populations in the W National Park of Benin

Fruits ◽  
2010 ◽  
Vol 65 (1) ◽  
pp. 11-19 ◽  
Author(s):  
Adandé Belarmain Fandohan ◽  
Achille Ephrem Assogbadjo ◽  
Romain Lucas Glele Kakaï ◽  
Brice Sinsin ◽  
Patrick Van Damme
Keyword(s):  
National Park ◽  
Conservation Status ◽  
Habitat Type

scholarly journals DENSITAS DAN AKTIVITAS AYAM HUTAN MERAH (Gallus gallus) DI HUTAN GUNUNG KLABAT, MINAHASA UTARA, SULAWESI UTARA

PHARMACON ◽  
2019 ◽  
Vol 8 (4) ◽  
pp. 1000
Author(s):  
Marton Puasa ◽  
Saroyo Saroyo ◽  
Lalu Wahyudi
Keyword(s):  
Feeding Activity ◽  
Habitat Type ◽  
Gallus Gallus ◽  
Survey Method ◽  
Line Transect ◽  
Type I ◽  
Forest Habitat ◽  
North Sulawesi ◽  
Red Jungle Fowl ◽  
The Right

ABSTRACTRed jungle fowl is one of the important animals that live in the forest and has various roles, such as ecological, economic and aesthetic functions. This study aims to analyze the population of red jungle fowl in forest habitat I and forest habitat II in the forest of Mount Klabat Utara Minahasa and analyze the activity of red forest chicken in forest habitat I and forest habitat II in the forests of Mount Klabat North Minahasa. This study uses a survey method with line transect sampling. Transects were determined as many as four, namely two transects in forest habitat type I and two transects in forest habitat type II. Each transect length is 2000 m and the left width is 20 m and the right width is 20 m, each transect is observed for 10 times. Density found in transect I was 25.63 animals / km² and transect II was 10.63 animals / km², in addition it was found that the dominant activity in both types of forest was forest I with feeding activity 19 (0.76%) moved 4 (0.16%), rest 2 (0.20%), in forest II looking for food, 5 (0.50%), move 3 (0.30%), rest 2 (0.20%).Keywords: Red jungle fowl (Gallus gallus), density, activity, Mount Klabat, North Minahasa, North Sulawesi ABSTRAKAyam hutan merah merupakan salah satu satwa penting yang hidup di hutan dan mempunyai berbagai peran, seperti fungsi ekologi, ekonomi dan estetika. Penelitian ini bertujuan menganalisis populasi ayam hutan merah pada habitat hutan I dan habitat hutan II di hutan Gunung Klabat Minahasa Utara dan menganalisis aktivitas ayam hutan merah pada habitat hutan I dan habitat hutan II di hutan Gunung Klabat Minahasa Utara. Penelitian ini menggunakan metode survei dengan sampling berbentuk transek garis. Transek ditentukan sebanyak empat, yaitu dua transek pada tipe habitat hutan I dan dua transek pada tipe habitat hutan II. Panjang transek masing-masing ialah 2000 m dan lebar kiri 20 m dan lebar kanan 20m, setiap transek dilakukan pengamatan selama 10 kali. Densitas yang di temukan pada transek I yaitu 25.63 ekor/km² dan di transek II 10.63 ekor/km², selain itu di temukan aktivitas yang dominan pada kedua tipe hutan yaitu hutan I dengan aktivitas makan 19 (0.76%) berpindah 4 (0.16%), istirahat 2 (0.20%), di hutan II mencari makan, 5 (0.50%), berpindah 3 (0.30%), istirahat 2 (0.20%).Kata kunci: Ayam hutan merah (Gallus gallus), densitas, aktivitas, Gunung Klabat, Minahasa Utara, Sulawesi Utara

scholarly journals Distribution, encounter rate and conservation status of Aquiloeurycea cafetalera (Caudata: Plethodontidae), a recently described Mexican salamander

2017 ◽  
Vol 16 (2) ◽  
pp. 211 ◽  
Author(s):  
José Luis Aguilar-López ◽  
Adriana Sandoval-Comte ◽  
Eduardo Pineda
Keyword(s):  
Spatial Distribution ◽  
Natural History ◽  
Potential Distribution ◽  
Anthropogenic Activities ◽  
Conservation Status ◽  
Encounter Rate ◽  
Sampling Effort ◽  
Natural Protected Areas ◽  
Plethodontid Salamander ◽  
Original Potential

The knowledge of the natural history of a species, its population traits and spatial distribution are essential to evaluate its risk of extinction and proposing strategies for its conservation. For poorly studied species inhabiting regions with a high degree of habitat conversion by anthropogenic activities, it is even more urgent to obtain this information. In this study, we carried out fieldwork and database analyses to obtain information on the ecology, natural history and spatial distribution of the plethodontid salamander Aquiloeurycea cafetalera, and we evaluated its conservation status according to the IUCN and the Mexican environmental agency (SEMARNAT). We found 109 individuals in 20 of the 43 localities visited (sampling effort = 1,174 person-hours). The salamander counts ranged from one to 21 individuals per locality and the average encounter rate was 21 salamanders per 100 person-hours of surveying, within a range from 2 to 117 salamanders. The current potential distribution calculated is about 2,000 km2 and fragmented, which means less than half of its original potential distribution. Our results suggest that it is necessary to include this species in biodiversity conservation programs because only a very small portion of its spatial distribution falls within natural protected areas.

scholarly journals List of Species and Conservation Status of Avifauna and Small mammal around Bade Segment Area of River Yobe, Yobe State, Nigeria

2021 ◽  
Vol 04 (12) ◽  
Author(s):  
Adam, L. I. ◽  
Keyword(s):  
Small Mammals ◽  
Small Mammal ◽  
Conservation Status ◽  
Habitat Type ◽  
Bird Species ◽  
Line Transect ◽  
Habitat Types ◽  
Mammal Species ◽  
River Bank ◽  
Small Mammal Species

The study was carried out to assess a Checklist of avifauna and small mammal species along Bade catchment area of Yobe State, Nigeria. Preliminary survey was conducted around the river, three (3) habitat types were identified; (river bank, farm lands and flood plain). The line transect was 8 km in length. Two (2) transects were established per habitat type, making a total of six (6) transects. The transects were 100 m apart to the left or right in order to avoid double counting of species. A distance of 200m was maintained between each habitat. The data obtained were analyses using descriptive statistics (Frequency tables and Charts were used to portrayed the findings. The result of the study; showed that a total of 50 bird species in 28 families were recorded. RB had the highest individuals of Fifty (50) species while FP has the lowest with ten (10) species. The Bird family Columbidae has the highest number with six (6) of species, while the lowest were Ardeidae, Sturnidae and Tytonidae with one species in each of the habitat types. However, checklist of small mammal species also indicated that a total of 6 species of small mammals belonging to 4 families were identified. The result of the study shows that the family Muridae has 3 species which was the highest number of per family identified in the study area, this is due to the fact that Muridae family are the most common small mammals in the study area. And both bird small species fell under least concern (LC) category except Pallid Harrier Circus macrourus which felled under near threatened (NT) species. However, awareness campaign should also be organize for the residents around the study area on the presence, distribution of bird and small mammal species and also disturbing effect of their activities on bird and small mammal around the segment area of river Yobe.

scholarly journals Using encounter rates as surrogates for density estimates makes monitoring of heavily-traded grey parrots achievable across Africa

Oryx ◽  
2015 ◽  
Vol 50 (4) ◽  
pp. 617-625 ◽  
Author(s):  
Stuart J. Marsden ◽  
Emmanuel Loqueh ◽  
Jean Michel Takuo ◽  
John A. Hart ◽  
Robert Abani ◽  
...  
Keyword(s):  
Local Density ◽  
Conservation Status ◽  
Distance Sampling ◽  
Central Africa ◽  
High Mobility ◽  
Encounter Rate ◽  
Line Transect ◽  
African Countries ◽  
Density Estimates ◽  
Encounter Rates

AbstractEstimating population sizes in the heavily traded grey parrots of West and Central Africa would provide insights into conservation status and sustainability of harvests. Ideally, density estimates would be derived from a standardized method such as distance sampling, but survey efforts are hampered by the extensive ranges, patchy distribution, variable abundance, cryptic habits and high mobility of the parrots as well as by logistical difficulties and limited resources. We carried out line transect distance sampling alongside a simpler encounter rate method at 10 sites across five West and Central African countries. Density estimates were variable across sites, from 0–0.5 individuals km−2 in Côte d'Ivoire and central Democratic Republic of the Congo to c. 30 km−2 in Cameroon and > 70 km−2 on the island of Príncipe. Most significantly, we identified the relationship between densities estimated from distance sampling and simple encounter rates, which has important applications in monitoring grey parrots: (1) to convert records of parrot groups encountered in a day's activities by anti-poaching patrols within protected areas into indicative density estimates, (2) to confirm low density in areas where parrots are so rare that distance sampling is not feasible, and (3) to provide a link between anecdotal records and local density estimates. Encounter rates of less than one parrot group per day of walking are a reality in most forests within the species’ ranges. Densities in these areas are expected to be one individual km−2 or lower, and local harvest should be disallowed on this basis.

scholarly journals Extension de l'aire de distribution de la Couleuvre à collier, Diadophis punctatus edwardsii, dans l'est du Québec

2005 ◽  
Vol 119 (3) ◽  
pp. 457
Author(s):  
Jean-François Desroches ◽  
Benoit Roussel
Keyword(s):  
National Park ◽  
Mixed Forest ◽  
Isolated Populations ◽  
Previous Record ◽  
North East ◽  
Diadophis Punctatus ◽  
Forêt Mixte

Deux Couleuvres à collier adulte (Diadophis punctatus edwardsii) ont été trouvées au parc national du Saguenay, dans l’est du Québec, en 2004 et 2005. Ces mentions se retrouvent à près 150 kilomètres au nord-nord-est de la mention la plus proche de l’espèce. L’habitat est constitué de forêt mixte près d’escarpements rocheux, dans des vallées. Il pourrait s’agir de populations isolées de celles retrouvées plus au sud.Two Ringneck Snakes (Diadophis punctatus edwardsii) was found in the Saguenay National Park, in eastern Québec, in 2004 and 2005. These records are about 150 kilometers north-north-east from the nearest previous record. The habitat is mixed forest, with rocky cliffs, in valleys. They may represent isolated populations from those found in southern Quebec.

Distribution and relative abundance of forest duikers in Dassioko Sud Forest Reserve (coastal Côte d'Ivoire)

2017 ◽  
Vol 44 (8) ◽  
pp. 660 ◽  
Author(s):  
K. A. Yao ◽  
E. A. Bitty ◽  
K. B. Kassé ◽  
Y. C. Kouakou ◽  
K. H. Yaokokoré-Beibro ◽  
...  
Keyword(s):  
Relative Abundance ◽  
Habitat Preferences ◽  
Habitat Type ◽  
Distribution Patterns ◽  
Encounter Rate ◽  
Line Transect ◽  
Habitat Types ◽  
Anthropogenic Pressures ◽  
Forest Reserve ◽  
Encounter Rates

Context Duikers play a vital role in maintaining forest ecosystems, as both seed dispersers and prey. In West Africa, duikers are also an important source of food and income; however, it is likely that some species are now being hunted at unsustainable levels. So as to contribute to duiker conservation, we used line-transect data and additional information on dung and track counts to estimate relative abundance and establish distribution patterns of forest duikers in Côte d’Ivoire’s Dassioko Sud Forest Reserve (DSFR), a poorly known, remnant coastal rainforest. We also collected basic information on hunting pressure. Methods Forest duiker counts were made twice per month from July 2013 to March 2014 on six line transects of varying lengths (5.6–6.7km) and in different regions of the DSFR, representing different habitat types. The number of sightings per kilometre walked, defined as ‘encounter rate’, was used to compute an index of relative abundance. We recorded all evidence of poachers and used these data to generate a poaching index (# poaching signs per kilometre) for different habitat types. Key results The DSFR has lost three of seven total forest duiker species and populations of the four remaining species are declining. Encounter rates were greatest for Philantomba maxwellii (0.46 indices km–1) and accounted for 68% of total encounters. Cephalophus niger, C. dorsalis and C. silvicultor were encountered at similar (0.07 indices km–1) but much lower rates. For all species, mean encounter rates were highest in degraded forest (0.38–0.73 indices km–1), followed by secondary (0.2–0.44 indices km–1) and primary (0.19–0.44 indices km–1) forest. Conclusions Of the four forest duiker species still present in the DSFR, the black, bay and yellow-backed duikers are the most affected by anthropogenic pressures. Duiker abundance in the DSFR varies with habitat type. This variation is apparently influenced by differences in forest structure, poaching pressure and proximity to villages. Implications The study provides baseline data for future managing of ungulate populations in the DSFR. We recommend that a biomonitoring study of duiker populations be initiated immediately to help determine population trends, investigate habitat preferences, and help curb illegal hunting activities in this important forest reserve.

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