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.

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.

AQUATIC COLEOPTERA OF SPRINGS IN CANADA

1991 ◽  
Vol 123 (S155) ◽  
pp. 125-140 ◽  
Author(s):  
R.E. Roughley ◽  
D.J. Larson
Keyword(s):  
United States ◽  
Habitat Preferences ◽  
Habitat Type ◽  
Beetle Species ◽  
Habitat Types ◽  
Diverse Families ◽  
Total Fauna ◽  
Habitat Affinities

AbstractThe habitat preferences of each of the 663 species of aquatic Coleoptera known from Canada and Alaska were categorized as lentic, lotic, spring-inhabiting, other, or unknown. Most species were assigned to a single habitat type although some occur in more than one habitat. The distribution of species among these habitat types is as follows: lentic, 61%; lotic, 23%; springs, 8%; other, <1%, unknown, 8%. The 63 spring-inhabiting species are distributed among the families Dytiscidae (38 species), Hydrophilidae (nine), Hydraenidae (eight), Chrysomelidae (subfamily Donaciinae) (six), Haliplidae (one), and Dryopidae (one). The diversity of these families in springs only approximately parallels their diversity in the total fauna. Several relatively diverse families (Gyrinidae, Scirtidae, and Curculionidae) are absent from springs as are some predominantly lotic families (Amphizoidae, Elmidae, and Psephenidae). About half the spring species are western (occurring in Manitoba and west), about a quarter are eastern, and a quarter are transcontinental. Most of these spring species are known from the conterminous United States and it is suggested that spring habitats within Canada are being colonized slowly from southern refugia.The habitat affinities of spring-inhabiting Dytiscidae are examined in detail. Of the 260 species occurring in Canada, 38 species occur in springs and represent about 60% of all beetle species in Canadian springs. The spring fauna of dytiscids comprises four elements: nine (24%) inhabit springs only, 11 (29%) are lotic species that also occur in springs, 12 (31%) are species that use a broad range of habitats, and six (16%) are species known otherwise only from lentic habitats. The dytiscid fauna of springs is a heterogeneous assemblage derived from many separate phylogenetic elements.

scholarly journals The ecology of Harwood’s Francolin Pternistis harwoodi (Aves: Galliformes: Phasianidae) at Merhabete District, central highlands of Ethiopia: implications for conservation

2017 ◽  
Vol 9 (9) ◽  
pp. 10633 ◽  
Author(s):  
Abadi Mehari Abrha ◽  
Habtu Kiros Nigus
Keyword(s):  
Habitat Preferences ◽  
Distance Sampling ◽  
Population Data ◽  
Encounter Rate ◽  
Line Transect ◽  
Digital Elevation ◽  
Firewood Collection ◽  
Dem Analysis ◽  
Elevation Model ◽  
Joint Contribution

This paper investigates the abundance, density and habitat preference of Harwood’s Francolin, and considers threats posed to this species at Merhabete District, Ethiopia. A total of 20 line transects ranging from 0.5–1.2 km, each 150–400 m apart, were placed in four study blocks. Habitat preferences were evaluated by digital elevation model (DEM) analysis and slope. Human pressures were also quantified based on circular plot placements along each line transect. Hence, distance sampling survey was used to count population data. The estimated population size and density were 184±26.46 birds and 43.48±6.25 birds/km2, respectively, with an overall encounter rate of 8.52 birds/km in Jema and Jara valleys. This species mainly preferred dry evergreen scrublands mixed with grassy, rock areas and dispersed acacia woodlands. However, based on stepwise regression model, the main threats to this species were burning, cutting, firewood collection and grazing. Generally, only cutting and firewood collection were the most important predictors that affected the focal species. This finding could be used to plan conservation of the species with the joint contribution of scientists, government and local communities.

scholarly journals Structure of Plants across Habitat Types in Amurum Forest Reserve, Plateau State Nigeria

2021 ◽  
Vol 25 (5) ◽  
pp. 847-850
Author(s):  
N. Janfa ◽  
M.J. Francis ◽  
C. Kambai ◽  
M.S. Chomini ◽  
S.A. Popoola ◽  
...  
Keyword(s):  
Habitat Type ◽  
Height Distribution ◽  
Gallery Forest ◽  
Diameter Class ◽  
Habitat Types ◽  
Forest Reserve ◽  
Diameter At Breast Height ◽  
Breast Height ◽  
Rocky Outcrop ◽  
Plateau State

The Amurum Forest Reserve is one of the nature reserves in Plateau State North central Nigeria. Strict Nature reserve is prominent among the methods for in situ conservation of biodiversity in Nigeria and also the world at large. A study was conducted in the Forest across three habitat types in order to measure tree height and diameter at breast height (dbh) of trees. 50m x 50m plots were marked across the habitat types by simple random sampling technique. Trees and shrubs were identified to species level. Measurement were limited to all woody plants with diameter at breast height (dbh) of ≥ 10cm. Data collected was analyzed in excel. A total of 397 woody species were identified during the study period. 87.7 of the plants were shrubs while 12.3% were trees. The gallery forest had the highest diameter class(30-35cm) followed by the savanna(25-30cm) and lastly the rocky outcrop with the diameter class of 20-25cm.The rocky outcrop had the highest number of trees with the lowest dbh (10-15cm) while the gallery forest had more trees in the highest diameter class (30-35) (Figure 2). The highest mean height distribution in the Gallery forest shows that the plant communities in this habitat type has grown over the years without disturbance since the place is a protected site. Therefore, other surrounding bushes should be protected in order to preserve species from local extinction.

scholarly journals Re-evaluating the salty divide: phylogenetic specificity of transitions between marine and freshwater systems

2018 ◽  
Author(s):  
Sara F. Paver ◽  
Daniel J. Muratore ◽  
Ryan J. Newton ◽  
Maureen L. Coleman
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Microbial Communities ◽  
Relative Abundance ◽  
Environmental Changes ◽  
Habitat Type ◽  
Freshwater Ecosystems ◽  
Rrna Gene ◽  
Minimum Entropy ◽  
Habitat Types

AbstractMarine and freshwater microbial communities are phylogenetically distinct and transitions between habitat types are thought to be infrequent. We compared the phylogenetic diversity of marine and freshwater microorganisms and identified specific lineages exhibiting notably high or low similarity between marine and freshwater ecosystems using a meta-analysis of 16S rRNA gene tag-sequencing datasets. As expected, marine and freshwater microbial communities differed in the relative abundance of major phyla and contained habitat-specific lineages; at the same time, however, many shared taxa were observed in both environments. Betaproteobacteria and Alphaproteobacteria sequences had the highest similarity between marine and freshwater sample pairs. Gammaproteobacteria and Alphaproteobacteria contained the highest number of Minimum Entropy Decomposition nodes shared by marine and freshwater samples. Shared nodes included lineages of the abundant alphaproteobacterial group SAR11 that have not previously been reported in 16S rRNA gene surveys of freshwater lakes. Our results suggest that shared taxa are numerous, but tend to occur sporadically and at low relative abundance in one habitat type, leading to an underestimation of transition frequency between marine and freshwater habitats. Lineages with a high degree of shared taxa or habitat-specific diversification represent targets for genome-scale investigations into microbial adaptations and evolutionary innovations. Rare taxa with abundances near or below detection, including lineages that appear to have crossed the salty divide relatively recently, may have novel adaptations enabling them to exploit opportunities for niche expansion when environments are disturbed or conditions change.ImportanceThe distribution of microbial diversity across environments yields insight into processes that create and maintain this diversity as well as potential to infer how communities will respond to future environmental changes. We integrated datasets from dozens of freshwater lake and marine samples to compare diversity across open water habitats differing in salinity. Our novel combination of sequence-based approaches revealed phyla and proteobacterial classes inferred to include more or less recent transitions across habitat types as well as specific lineages that are shared by marine and freshwater environments at the level of 16S rRNA sequence types. Our findings contribute to understanding the ecological and evolutionary controls on microbial distributions, and open up new questions regarding the plasticity and adaptability of particular lineages.

scholarly journals Spatial distribution of stygobitic crustacean harpacticoids at the boundaries of groundwater habitat types in Europe

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Mattia Iannella ◽  
Barbara Fiasca ◽  
Tiziana Di Lorenzo ◽  
Maurizio Biondi ◽  
Mattia Di Cicco ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Habitat Type ◽  
Distribution Patterns ◽  
Unconsolidated Sediments ◽  
Habitat Types ◽  
Habitat Patches ◽  
Exponential Models ◽  
Proximity Analysis ◽  
Hydrogeological Properties ◽  
Dispersal Abilities

Abstract The distribution patterns of stygobitic crustacean harpacticoids at the boundaries of three different groundwater habitat types in Europe were analysed through a GIS proximity analysis and fitted to exponential models. The results showed that the highest frequency of occurrences was recorded in aquifers in consolidated rocks, followed by the aquifers in unconsolidated sediments and, finally, by the practically non-aquiferous rocks. The majority of the stygobitic harpacticoid species were not able to disperse across the boundaries between two adjacent habitats, with 66% of the species occurring in a single habitat type. The species were not evenly distributed, and 35–69% of them occurred from 2 to 6 km to the boundaries, depending on the adjacent habitat types. The distribution patterns were shaped by features extrinsic to the species, such as the hydrogeological properties of the aquifers, and by species’ intrinsic characteristics such as the preference for a given habitat type and dispersal abilities. Most boundaries between adjacent habitat types resulted to be “breaches”, that is transmissive borders for stygobitic harpacticoids, while others were “impermeable walls”, that is absorptive borders. Our results suggest that conservation measures of groundwater harpacticoids should consider how species are distributed within the different groundwater habitat types and at their boundaries to ensure the preservation of species metapopulations within habitat patches and beyond them.

scholarly journals Reevaluating the Salty Divide: Phylogenetic Specificity of Transitions between Marine and Freshwater Systems

mSystems ◽  
2018 ◽  
Vol 3 (6) ◽  
Author(s):  
Sara F. Paver ◽  
Daniel Muratore ◽  
Ryan J. Newton ◽  
Maureen L. Coleman
Keyword(s):  
16S Rrna ◽  
Microbial Communities ◽  
Relative Abundance ◽  
Environmental Changes ◽  
Habitat Type ◽  
Freshwater Ecosystems ◽  
Rrna Gene ◽  
Data Sets ◽  
Sequencing Data ◽  
Habitat Types

ABSTRACTMarine and freshwater microbial communities are phylogenetically distinct, and transitions between habitat types are thought to be infrequent. We compared the phylogenetic diversity of marine and freshwater microorganisms and identified specific lineages exhibiting notably high or low similarity between marine and freshwater ecosystems using a meta-analysis of 16S rRNA gene tag-sequencing data sets. As expected, marine and freshwater microbial communities differed in the relative abundance of major phyla and contained habitat-specific lineages. At the same time, and contrary to expectations, many shared taxa were observed in both habitats. Based on several metrics, we found thatGammaproteobacteria,Alphaproteobacteria,Bacteroidetes, andBetaproteobacteriacontained the highest number of closely related marine and freshwater sequences, suggesting comparatively recent habitat transitions in these groups. Using the abundant alphaproteobacterial group SAR11 as an example, we found evidence that new lineages, beyond the recognized LD12 clade, are detected in freshwater at low but reproducible abundances; this evidence extends beyond the 16S rRNA locus to core genes throughout the genome. Our results suggest that shared taxa are numerous, but tend to occur sporadically and at low relative abundance in one habitat type, leading to an underestimation of transition frequency between marine and freshwater habitats. Rare taxa with abundances near or below detection, including lineages that appear to have crossed the salty divide relatively recently, may possess adaptations enabling them to exploit opportunities for niche expansion when environments are disturbed or conditions change.IMPORTANCEThe distribution of microbial diversity across environments yields insight into processes that create and maintain this diversity as well as potential to infer how communities will respond to future environmental changes. We integrated data sets from dozens of freshwater lake and marine samples to compare diversity across open water habitats differing in salinity. Our novel combination of sequence-based approaches revealed lineages that likely experienced a recent transition across habitat types. These taxa are promising targets for studying physiological constraints on salinity tolerance. Our findings contribute to understanding the ecological and evolutionary controls on microbial distributions, and open up new questions regarding the plasticity and adaptability of particular lineages.

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 Assessing Distribution Patterns and the Relative Abundance of Reintroduced Large Herbivores in the Limpopo National Park, Mozambique

Diversity ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 456
Author(s):  
Dionísio Virgílio Roque ◽  
Thomas Göttert ◽  
Valério António Macandza ◽  
Ulrich Zeller
Keyword(s):  
Relative Abundance ◽  
National Park ◽  
Distribution Patterns ◽  
Intermediate Stage ◽  
Camera Traps ◽  
Specific Response ◽  
Habitat Types ◽  
Large Herbivore ◽  
Large Herbivores ◽  
Abundance Index

This study is the first systematic assessment of large herbivore (LH) communities in Limpopo National Park (LNP) in Mozambique, an area where most LH species were extinct until the early 2000s. We investigate whether LH community parameters are linked with the availability of habitat types or the distance between sampling sites and the origin of LH resettlement. We placed camera traps in five habitat types in resettled and not-resettled areas to compare species richness, relative abundance index, grazers–browsers–mixed feeder ratio and naïve occupancy of 15 LH species. While the richness decreased along the distance gradient of LH resettlement, relative abundance index strongly responded to habitat features. Among habitat types, the browsers ratio oscillated, while from resettled to not-resettled areas, the ratio increased. Most species showed a wider distribution range among habitat types. The associations of most LH community parameters with habitat types rather than distance to initial release, together with the species-specific and guild-specific response patterns of LH, suggest LNP to already be in an intermediate stage of restoration. Our results highlight the importance of post-release monitoring of reintroduced wildlife as a tool to assess the success of ecological restoration initiatives in transboundary conservation areas.

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.

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