scholarly journals Tapirs in trouble: estimating Baird's tapir densities in the Sierra Madre de Chiapas, Mexico

Oryx ◽  
2021 ◽  
pp. 1-10
Author(s):  
Marina Rivero ◽  
J. Antonio de la Torre ◽  
Gamaliel Camacho ◽  
Eduardo J. Naranjo ◽  
Mathias W. Tobler ◽  
...  
Keyword(s):  
Protected Areas ◽  
Coefficient Of Variation ◽  
Action Plan ◽  
Camera Trap ◽  
The Other ◽  
Population Estimate ◽  
Occupancy Models ◽  
Southern Mexico ◽  
Sierra Madre ◽  
Capture Recapture

Abstract Spatial capture–recapture models have been widely used to estimate densities of species where individuals can be uniquely identified, but alternatives have been developed for estimation of densities for unmarked populations. In this study we used camera-trap records from 2018 to estimate densities of a species that does not always have individually identifiable marks, Baird's tapir Tapirus bairdii, in the Sierra Madre de Chiapas, southern Mexico. We compared the performance of the spatial capture–recapture model with spatial mark–resight and random encounter models. The density of Baird's tapir did not differ significantly between the three models. The estimate of density was highest using the random encounter model (26/100 km2, 95% CI 12–41) and lowest using the capture–recapture model (8/100 km2, 95% CI 4–16). The estimate from the spatial mark–resight model was 10/100 km2 (95% CI 8–14), which had the lowest coefficient of variation, indicating a higher precision than with the other models. Using a second set of camera-trap data, collected in 2015–2016, we created occupancy models and extrapolated density to areas with potential occupancy of Baird's tapir, to generate a population estimate for the whole Sierra Madre de Chiapas. Our findings indicate the need to strengthen, and possibly expand, the protected areas of southern Mexico and to develop an action plan to ensure the conservation of Baird's tapir.

A revision of the New World Euphorbia adiantoides complex (Euphorbiaceae)

Phytotaxa ◽  
2018 ◽  
Vol 350 (3) ◽  
pp. 201
Author(s):  
VICTOR W. STEINMANN ◽  
PABLO CARRILLO-REYES
Keyword(s):  
New World ◽  
Phylogenetic Analyses ◽  
The Other ◽  
Central Mexico ◽  
Northern Population ◽  
Southern Mexico ◽  
Sierra Madre ◽  
Peripatric Speciation ◽  
Nuclear Its ◽  
Multiple Samples

The Euphorbia adiantoides complex is here considered to consist of four species. This group is readily distinguished from other New World Euphorbia by the combination of two unusual features: entire styles with capitate stigmas and dichasial bracts with relatively long, filiform stipules. Euphorbia sonorae is reduced to a synonym of Euphorbia adiantoides, a taxon disjunctly distributed between Mexico and western South America. The other species of the complex are all restricted to Mexico. Two of these are described as new: E. zamudioi, an endemic to the Sierra Madre Oriental, and E. breedlovei, which is widespread in central and southern Mexico. A key to distinguish the species is provided, as too are data concerning their morphology, distribution, habitat, phenology, common names, and uses. Phylogenetic analyses were conducted using the nuclear ITS and the chloroplast psbA-trnH regions and including multiple samples of each species. The phylogenetic results are not always congruent with morphology, and of the four species herein recognized, only Euphorbia zamudioi is suggested to form an exclusive, well-supported lineage. This species is nested within E. breedlovei, and two collections of E. breedlovei from central Mexico are more closely related to E. zamudioi than they are to other E. breedlovei from southern Mexico. We hypothesize that E. zamudioi arose through peripatric speciation, in which a northern population of E. breedlovei became reproductively isolated and morphologically differentiated from the remainder of the populations of E. breedlovei.

scholarly journals Ground Reaction Forces of Dressage Horses Performing the Piaffe

Animals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 436 ◽  
Author(s):  
Hilary Mary Clayton ◽  
Sarah Jane Hobbs
Keyword(s):  
Coefficient Of Variation ◽  
Three Dimensional ◽  
Individual Variability ◽  
The Other ◽  
Ground Reaction Forces ◽  
High Coefficient ◽  
Reaction Forces

The piaffe is an artificial, diagonally coordinated movement performed in the highest levels of dressage competition. The ground reaction forces (GRFs) of horses performing the piaffe do not appear to have been reported. Therefore, the objective of this study was to describe three-dimensional GRFs in ridden dressage horses performing the piaffe. In-ground force plates were used to capture fore and hindlimb GRF data from seven well-trained dressage horses. Peak vertical GRF was significantly higher in forelimbs than in the hindlimbs (7.39 ± 0.99 N/kg vs. 6.41 ± 0.64 N/kg; p < 0.001) with vertical impulse showing a trend toward higher forelimb values. Peak longitudinal forces were small with no difference in the magnitude of braking or propulsive forces between fore and hindlimbs. Peak transverse forces were similar in magnitude to longitudinal forces and were mostly directed medially in the hindlimbs. Both the intra- and inter-individual variability of longitudinal and transverse GRFs were high (coefficient of variation 25–68%). Compared with the other diagonal gaits of dressage horses, the vertical GRF somewhat shifted toward the hindlimbs. The high step-to-step variability of the horizontal GRF components is thought to reflect the challenge of balancing on one diagonal pair of limbs with no forward momentum.

Urinary melatonin, LH, oestradiol, progesterone excretion during the menstrual cycle or in women taking oral contraceptives

1987 ◽  
Vol 116 (1) ◽  
pp. 145-149 ◽  
Author(s):  
Jocelyne Brun ◽  
Bruno Claustrat ◽  
Michel David
Keyword(s):  
Oral Contraceptive ◽  
Menstrual Cycle ◽  
Urinary Excretion ◽  
Oral Contraceptives ◽  
Coefficient Of Variation ◽  
Luteal Phase ◽  
Positive Relationship ◽  
Follicular Phase ◽  
The Other ◽  
Normal Women

Abstract. Nocturnal urinary excretion of melatonin, LH, progesterone and oestradiol was measured by radioimmunoassay in nine normal women during a complete cycle. In addition, these hormonal excretions were studied in two women taking an oral contraceptive. A high within-subject coefficient of variation was observed for melatonin excretion in the two groups. In the nine normal cycling women, melatonin excretion was not decreased at the time of ovulation, but was significantly increased during the luteal phase compared with that of the follicular phase (P < 0.01). These data are consistent with a positive relationship between melatonin and progesterone during the luteal phase. In the two women under an oral contraceptive, melatonin excretion was found within the same range as for the other nine. The results are discussed in terms of pineal investigation in human.

scholarly journals A sparse observation model to quantify species interactions in time and space

2019 ◽  
Author(s):  
Sadoune Ait Kaci Azzou ◽  
Liam Singer ◽  
Thierry Aebischer ◽  
Madleina Caduff ◽  
Beat Wolf ◽  
...  
Keyword(s):  
Species Interactions ◽  
Activity Patterns ◽  
Niche Partitioning ◽  
Camera Trap ◽  
Camera Traps ◽  
Observation Model ◽  
Occupancy Models ◽  
Time And Space ◽  
Imperfect Detection ◽  
Mobile Species

SummaryCamera traps and acoustic recording devices are essential tools to quantify the distribution, abundance and behavior of mobile species. Varying detection probabilities among device locations must be accounted for when analyzing such data, which is generally done using occupancy models. We introduce a Bayesian Time-dependent Observation Model for Camera Trap data (Tomcat), suited to estimate relative event densities in space and time. Tomcat allows to learn about the environmental requirements and daily activity patterns of species while accounting for imperfect detection. It further implements a sparse model that deals well will a large number of potentially highly correlated environmental variables. By integrating both spatial and temporal information, we extend the notation of overlap coefficient between species to time and space to study niche partitioning. We illustrate the power of Tomcat through an application to camera trap data of eight sympatrically occurring duiker Cephalophinae species in the savanna - rainforest ecotone in the Central African Republic and show that most species pairs show little overlap. Exceptions are those for which one species is very rare, likely as a result of direct competition.

scholarly journals Repenser Le Rôle Des Institutions De Conservation De La Nature À L’ère De La Globalisation En Afrique: À Propos Du Parc National De La Salonga (RDC)

2017 ◽  
Vol 13 (11) ◽  
pp. 92
Author(s):  
Mampeta Wabasa Salomon
Keyword(s):  
Protected Areas ◽  
National Park ◽  
Local Community ◽  
Democratic Republic ◽  
Central Africa ◽  
The Other ◽  
African Countries ◽  
Republic Of The Congo ◽  
Contemporary Management

In the Democratic Republic of the Congo (DRC), the protectionist conservatism influenced by colonialism, which exploited African countries for the prosperity of the colonizing countries, still has a high visibility in the Salonga National Park (PNS). If, in theory, the Central Africans seem to free themselves from the colonial powers on their land, in practice they are still there. The hostility of settlers who have become neo-colonists to the development of Central Africa remains intact, he adds (Ndinga, 2003). This reflects a "logic from above" that has disregarded local values. Yet, in the era of sustainable development and globalization, African protected areas appear to be essential tools for States to reposition themselves in a complex set of actors with the aim of capturing and using the new environmental rent (Giraut, Guyot, & Houssay-Holzschuch, 2003). This is a "bottom-up logic", placing people at the heart of all activities and aiming to reorganize their long-term relationships with the environment. From these two logics, a third "logic from the other side" emerges, reflecting a collective awareness of the fragility of the planet. The restoration of the rights of Africans in the various national frameworks constitutes a major challenge for the contemporary management of African protected areas. Because the protected areas inherited from the different colonial systems must accompany the change in management methods and the redefinition of their functions in order to better serve the local community in the long-term.

scholarly journals The competitiveness of the phytosociological attributes of the protected areas in Bangladesh with that in the other tropical countries

2016 ◽  
Vol 35 (6) ◽  
pp. 431-450 ◽  
Author(s):  
Mohammad Mahfuzur Rahman ◽  
Md. Abdullah Al Mahmud ◽  
Mohammad Shahidullah ◽  
Tapan Kumar Nath ◽  
Mohammed Jashimuddin
Keyword(s):  
Protected Areas ◽  
The Other ◽  
Tropical Countries

The valuation of elephant sightings in protected areas.

2021 ◽  
pp. 191-203
Author(s):  
Andrea Saayman ◽  
Melville Saayman
Keyword(s):  
South Africa ◽  
Willingness To Pay ◽  
Contingent Valuation ◽  
Protected Areas ◽  
National Parks ◽  
Big Five ◽  
The Other ◽  
Relative Importance ◽  
The Mean ◽  
Preferred Species

Abstract The research presented in this chapter determines the value that tourists on safari in protected areas in South Africa attach to elephant sightings and the relative importance of the elephant sighting compared with the other species in the Big Five. The study also determines whether tourists take the increased poaching of elephants - also in South Africa - into account when revealing their choice. Using information from five surveys conducted at different parks in South Africa from 2011 to 2013 and again in 2019, the elephant was found to be the fourth preferred species in the Big Five. The exception is Addo Elephant National Park, where the elephants are the second most preferred species. To determine the value that tourists attached to a sighting, contingent valuation was used. Although approximately a quarter to a third of respondents indicated positive amounts for a sighting across the years, the mean willingness to pay (WTP) reflects the scarcity of the species. The elephant is relatively abundant in all the parks and, in many instances, much easier to spot than the leopard or lion. It is therefore not surprising that the mean valuation of a sighting is much lower than that of the leopard and lion throughout all the years. Although tougher economic conditions in the country also influence WTP, it was found that tourists to South Africa's National Parks do not yet take the increased poaching of elephants into account when revealing their choice, nor in their valuation.

scholarly journals Do conservation strategies that increase tiger populations have consequences for other wild carnivores like leopards?

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Ujjwal Kumar ◽  
Neha Awasthi ◽  
Qamar Qureshi ◽  
Yadvendradev Jhala
Keyword(s):  
Species Conservation ◽  
Camera Trap ◽  
Conservation Strategies ◽  
Spatially Explicit ◽  
Large Carnivores ◽  
Catchment Scale ◽  
Large Carnivore ◽  
Positive Growth ◽  
Capture Recapture ◽  
Very High

Abstract Most large carnivore populations are declining across their global range except in some well managed protected areas (PA’s). Investments for conserving charismatic apex carnivores are often justified due to their umbrella effect on biodiversity. We evaluate population trends of two large sympatric carnivores, the tiger and leopard through spatially-explicit-capture-recapture models from camera trap data in Kanha PA, India, from 2011 to 2016. Our results show that the overall density (100 km−2) of tigers ranged between 4.82 ± 0.33 to 5.21 ± 0.55SE and of leopards between 6.63 ± 0.71 to 8.64 ± 0.75SE, with no detectable trends at the PA scale. When evaluated at the catchment scale, Banjar catchment that had higher prey density and higher conservation investments, recorded significant growth of both carnivores. While Halon catchment, that had lower prey and conservation investments, populations of both carnivores remained stable. Sex ratio of both carnivores was female biased. As is typical with large carnivores, movement parameter sigma (an index for range size), was larger for males than for females. However, sigma was surprisingly similar for the same genders in both carnivores. At home-range scale, leopards achieved high densities and positive growth rates in areas that had low, medium or declining tiger density. Our results suggest that umbrella-species conservation value of tigers is likely to be compromised at very high densities and therefore should not be artificially inflated through targeted management.

scholarly journals Daily Activity Patterns and Co-Occurrence of Duikers Revealed by an Intensive Camera Trap Survey across Central African Rainforests

Animals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 2200
Author(s):  
Fructueux G. A. Houngbégnon ◽  
Daniel Cornelis ◽  
Cédric Vermeulen ◽  
Bonaventure Sonké ◽  
Stephan Ntie ◽  
...  
Keyword(s):  
Daily Activity ◽  
Activity Patterns ◽  
Camera Trap ◽  
Camera Traps ◽  
The Other ◽  
Species Pairs ◽  
Free Ranging ◽  
First Time ◽  
Daily Activity Patterns ◽  
Temporal Overlap

The duiker community in Central African rainforests includes a diversity of species that can coexist in the same area. The study of their activity patterns is needed to better understand habitat use or association between the species. Using camera traps, we studied the temporal activity patterns, and quantified for the first time the temporal overlap and spatial co-occurrence between species. Our results show that: (i) Two species are strongly diurnal: Cephalophus leucogaster, and Philantomba congica, (ii) two species are mostly diurnal: C.callipygus and C. nigrifrons, (iii) one species is strongly nocturnal: C.castaneus, (iv) and one species is mostly nocturnal: C.silvicultor. Analyses of temporal activities (for five species) identified four species pairs that highly overlapped (Δ^≥ 0.80), and six pairs that weakly overlapped (Δ^ between 0.06 and 0.35). Finally, co-occurrence tests reveal a truly random co-occurrence (plt > 0.05 and pgt > 0.05) for six species pairs, and a positive co-occurrence (pgt < 0.05) for four pairs. Positive co-occurrences are particularly noted for pairs formed by C.callipygus with the other species (except C. nigrifrons). These results are essential for a better understanding of the coexistence of duikers and the ecology of poorly known species (C. leucogaster and C. nigrifrons), and provide clarification on the activity patterns of C. silvicultor which was subject to controversy. Camera traps proved then to be a powerful tool for studying the activity patterns of free-ranging duiker populations.

scholarly journals Animal movement affects interpretation of occupancy models from camera‐trap surveys of unmarked animals

Ecosphere ◽  
2018 ◽  
Vol 9 (1) ◽  
Author(s):  
Eric W. Neilson ◽  
Tal Avgar ◽  
A. Cole Burton ◽  
Kate Broadley ◽  
Stan Boutin
Keyword(s):  
Animal Movement ◽  
Camera Trap ◽  
Occupancy Models
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