scholarly journals Spatial Niche Expansion at Multiple Habitat Scales of a Tropical Freshwater Turtle in the Absence of a Potential Competitor

Diversity ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 55 ◽  
Author(s):  
Fabio Petrozzi ◽  
Stephanie N. Ajong ◽  
Nic Pacini ◽  
Daniele Dendi ◽  
Sery Gonedele Bi ◽  
...  
Keyword(s):  
West Africa ◽  
Ivory Coast ◽  
Aquatic Vegetation ◽  
Spatial Scales ◽  
Habitat Preferences ◽  
Freshwater Turtle ◽  
Widespread Species ◽  
Turtle Species ◽  
Natural Systems ◽  
Spatial Niche

Resource partitioning, the division of limited resources by species to help avoid competition, has been observed in freshwater turtle assemblages in several natural systems but has rarely been studied in tropical African ecosystems. Here, we investigate habitat preferences of two congeneric species in the family Pelomedusidae, Pelusios castaneus and P. cupulatta, in riverine/wetland habitats in the southern Ivory Coast (West Africa). Pelusios castaneus is a widespread species across West-central African savannahs and open forests, whereas P. cupulatta is endemic to the Upper Guinean forest region in West Africa. The two species have a similar diet composition (mainly carnivorous) but diverge considerably in body size, P. cupulatta being much larger. We use hand-fishing-nets and fishing funnel traps to record turtles in 18 distinct sites and analyze habitat preferences by species at two spatial scales. At a macro-habitat scale, P. castaneus is captured mainly in marshlands, whereas P. cupulatta is found in both rivers and wetlands. The two species differ significantly in their use of: (i) banks (P. castaneus being found primarily in spots with grassy banks, whereas P. cupulatta is found in spots with forested banks), and (ii) aquatic vegetation (P. cupulatta prefers spots with more abundant aquatic vegetation than P. castaneus), but both species select sites with no or moderate current. Additionally, in sites where P. cupulatta is not found, P. castaneus expands its spatial niche at multiple habitat scales, notably invading waterbodies with forested banks. Our results suggest that these two Pelomedusid turtle species potentially compete in the freshwater habitats in the southern Ivory Coast.

scholarly journals Predicting the structure of turtle assemblages along a megatransect in West Africa

2020 ◽  
Vol 130 (2) ◽  
pp. 296-309
Author(s):  
Luca Luiselli ◽  
Godfrey C Akani ◽  
Stephanie N Ajong ◽  
Adedolapo George ◽  
Massimiliano Di Vittorio ◽  
...  
Keyword(s):  
Species Richness ◽  
West Africa ◽  
Common Species ◽  
Community Diversity ◽  
Freshwater Turtle ◽  
Small Scale ◽  
Microhabitat Use ◽  
Evolutionary Mechanisms ◽  
Turtle Species ◽  
Ecological Requirements

Abstract Understanding large- and small-scale patterns and the determinants of species richness is central for the study of evolutionary mechanisms. The extent to which species richness in local communities is related to larger-scale processes is a pre-eminent topic in ecological and evolutionary research. To investigate how local and regional species richness are related, we sampled freshwater turtle assemblages in seven localities to represent the variation in ecological conditions along a 90 km south–north megatransect in Benin, West Africa. In each locality, all turtles captured were identified and measured, and the microhabitat in which individual turtles were observed was classified. Based on these data, we used community diversity metrics to compare turtle assemblages. Spatial autocorrelation did not affect our data. For all localities pooled, two species (Pelusios castaneus and Pelomedusa olivacea) were the most common and one species (Trionyx triunguis) was the rarest. Analyses of the commonest and more numerous species showed that the abundance of Pelusios castaneus declined with an increase in latitude and longitude, but the opposite was true for Pelomedusa olivacea. We showed that various characteristics of the microhabitat were significantly correlated with the abundance of the two common species. We found significant but variable south–north gradients in microhabitat use for different turtle species. Our results highlight the importance of studying interactions between local environments, the ecological requirements of each species and their synecological relationships.

Community Characteristics of Sympatric Freshwater Turtles From Savannah Waterbodies in Ghana

2021 ◽  
Author(s):  
Suleman B. Gbewaa ◽  
S. Kobby Oppong ◽  
Brian D. Horne ◽  
Paul Tehoda ◽  
Fabio Petrozzi ◽  
...  
Keyword(s):  
West Africa ◽  
Correspondence Analysis ◽  
Habitat Type ◽  
Habitat Associations ◽  
Emergent Vegetation ◽  
Community Diversity ◽  
Freshwater Turtle ◽  
Physical Habitat ◽  
Freshwater Turtles ◽  
Turtle Species

Abstract Despite increasing pressures on freshwater resources worldwide, and the threatened status of most freshwater turtles, there is still limited knowledge of habitat use and niche partitioning in Afrotropical freshwater turtle communities. In this study, we describe habitat associations, community diversity, and temporal patterns of occurrence of freshwater turtle species in the Dahomey Gap ecoregion of Ghana (West Africa). We gathered data from 13 sites in central Ghana and along the Sene Arm of Lake Volta in the Digya National Park (Bono East Region). We employed opportunistic short-term surveys (at seven sites) together with longer-term (six-months duration) standardized evaluations of turtle presence and numbers in different habitats (at six sites). In addition, we interviewed fishers in the Lake Volta area to explore their perception about turtle abundance trends. Overall, 210 turtle individuals belonging to four species (Trionyx triunguis, Cyclanorbis senegalensis, Pelomedusa sp. and Pelusios castaneus) were recorded; for 139 individuals the precise capture sites and habitat type were recorded, whereas 71 individuals were observed in market places and were not considered in our analyses. We observed three sympatric species at the local scale of the various study sites. In each site, the dominant species was either C. senegalensis or Pelomedusa sp. However, Pelomedusa sp. was the most abundant species in temporary waterbodies whereas C. senegalensis was more numerous in permanent ones. A Multiple Correspondence Analysis visualized that, in permanent waterbodies all species were associated with similar physical habitat variables. C. senegalensis and T. triunguis were more abundant in localities containing woody emergent vegetation and inorganic substrate. In a Canonical Correspondence Analysis, we show that the density of herbaceous emergent vegetation was more important for P. castaneus than for C. senegalensis. Interviews with local people suggested that freshwater turtles do not have any special marketing interest for them, but that overfishing may have considerably affected the population density of these semiaquatic reptiles. Overall, Comparisons of diversity metrics between our study areas and previous literature revealed that turtle community composition was substantially the same, both qualitatively and quantitatively, all throughout the savannahs of West Africa.

scholarly journals Plastic ingestion by freshwater turtles: a review and call to action

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Adam G. Clause ◽  
Aaron J. Celestian ◽  
Gregory B. Pauly
Keyword(s):  
Marine Species ◽  
Marine Turtle ◽  
Freshwater Turtle ◽  
Freshwater Turtles ◽  
Plastic Pollution ◽  
Potential Threat ◽  
Implementation Quality ◽  
Turtle Species ◽  
Marine Turtles ◽  
Conservation Concern

AbstractPlastic pollution, and especially plastic ingestion by animals, is a serious global issue. This problem is well documented in marine systems, but it is relatively understudied in freshwater systems. For turtles, it is unknown how plastic ingestion compares between marine and non-marine species. We review the relevant turtle dietary literature, and find that plastic ingestion is reported for all 7 marine turtle species, but only 5 of 352 non-marine turtle species. In the last 10 years, despite marine turtles representing just 2% of all turtle species, almost 50% of relevant turtle dietary studies involved only marine turtles. These results suggest that the potential threat of plastic ingestion is poorly studied in non-marine turtles. We also examine plastic ingestion frequency in a freshwater turtle population, finding that 7.7% of 65 turtles had ingested plastic. However, plastic-resembling organic material would have inflated our frequency results up to 40% higher were it not for verification using Raman spectroscopy. Additionally, we showcase how non-native turtles can be used as a proxy for understanding the potential for plastic ingestion by co-occurring native turtles of conservation concern. We conclude with recommendations for how scientists studying non-marine turtles can improve the implementation, quality, and discoverability of plastic ingestion research.

Vegetation of seasonal rock pools on inselbergs situated in the savanna zone of the Ivory Coast (West Africa)

Flora ◽  
2000 ◽  
Vol 195 (3) ◽  
pp. 257-266 ◽  
Author(s):  
Axel Krieger ◽  
Stefan Porembski ◽  
Wilhelm Barthlott
Keyword(s):  
West Africa ◽  
Ivory Coast ◽  
Rock Pools ◽  
Savanna Zone

Prevalence of Antibody to Human T Cell Leukemia Virus Type 1 (HTLV-I) in Populations of Ivory Coast, West Africa

1989 ◽  
Vol 160 (3) ◽  
pp. 363-370 ◽  
Author(s):  
M. Verdier ◽  
F. Denis ◽  
A. Sangare ◽  
F. Barin ◽  
G. Gershy-Damet ◽  
...  
Keyword(s):  
T Cell ◽  
West Africa ◽  
Virus Type ◽  
Ivory Coast ◽  
Leukemia Virus ◽  
Cell Leukemia ◽  
Cell Leukemia Virus Type ◽  
Human T Cell ◽  
T Cell Leukemia Virus

scholarly journals Sugarcane Yield Forecast in Ivory Coast (West Africa) Based on Weather and Vegetation Index Data

Atmosphere ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 1459
Author(s):  
Edouard Pignède ◽  
Philippe Roudier ◽  
Arona Diedhiou ◽  
Vami Hermann N’Guessan Bi ◽  
Arsène T. Kobea ◽  
...  
Keyword(s):  
West Africa ◽  
Ivory Coast ◽  
Vegetation Index ◽  
Cultural Practices ◽  
Machine Learning Algorithms ◽  
Climate Data ◽  
Climate Services ◽  
Climate Risks ◽  
The North ◽  
Sugarcane Yield

One way to use climate services in the case of sugarcane is to develop models that forecast yields to help the sector to be better prepared against climate risks. In this study, several models for forecasting sugarcane yields were developed and compared in the north of Ivory Coast (West Africa). These models were based on statistical methods, ranging from linear regression to machine learning algorithms such as the random forest method, fed by climate data (rainfall, temperature); satellite products (NDVI, EVI from MODIS Vegetation Index product) and information on cropping practices. The results show that the forecasting of sugarcane yield depended on the area considered. At the plot level, the noise due to cultivation practices can hide the effects of climate on yields and leads to poor forecasting performance. However, models using satellite variables are more efficient and those with EVI alone may explain 43% of yield variations. Moreover, taking into account cultural practices in the model improves the score and enables one to forecast 3 months before harvest in 50% and 69% of cases whether yields will be high or low, respectively, with errors of only 10% and 2%, respectively. These results on the predictive potential of sugarcane yields are useful for planning and climate risk management in this sector.

Sign in / Sign up

Export Citation Format

Share Document