Using genetic analysis to estimate population size, sex ratio, and social organization in an Asian elephant population in conflict with humans in Alur, southern India

2014 ◽  
Vol 15 (4) ◽  
pp. 897-907 ◽  
Author(s):  
Subhankar Chakraborty ◽  
D. Boominathan ◽  
Ajay A. Desai ◽  
T. N. C. Vidya
Keyword(s):  
Sex Ratio ◽  
Genetic Analysis ◽  
Social Organization ◽  
Population Size ◽  
Asian Elephant ◽  
Southern India ◽  
Elephant Population ◽  
Estimate Population Size

scholarly journals Social structure and demography of a remnant Asian elephant Elephas maximus population and the implications for survival

Oryx ◽  
2020 ◽  
pp. 1-6
Author(s):  
Lauren J. Hale ◽  
Kun Shi ◽  
Tania C. Gilbert ◽  
Kelvin S.-H. Peh ◽  
Philip Riordan
Keyword(s):  
Social Structure ◽  
Population Size ◽  
Total Population ◽  
Camera Traps ◽  
Asian Elephant ◽  
Elephas Maximus ◽  
Effective Density ◽  
Anthropogenic Pressures ◽  
Sex Ratio Bias ◽  
Elephant Population

Abstract The Asian elephant Elephas maximus is at risk of extinction as a result of anthropogenic pressures, and remaining populations are often small and fragmented remnants, occupying a fraction of the species' former range. Once widely distributed across China, only a maximum of 245 elephants are estimated to survive across seven small populations. We assessed the Asian elephant population in Nangunhe National Nature Reserve in Lincang Prefecture, China, using camera traps during May–July 2017, to estimate the population size and structure of this genetically important population. Although detection probability was low (0.31), we estimated a total population size of c. 20 individuals, and an effective density of 0.39 elephants per km2. Social structure indicated a strong sex ratio bias towards females, with only one adult male detected within the population. Most of the elephants associated as one herd but three adult females remained separate from the herd throughout the trapping period. These results highlight the fragility of remnant elephant populations such as Nangunhe and we suggest options such as a managed metapopulation approach for their continued survival in China and more widely.

An elephantine challenge: human–elephant conflict distribution in the largest Asian elephant population, southern India

2014 ◽  
Vol 23 (3) ◽  
pp. 633-647 ◽  
Author(s):  
Sanjay Gubbi ◽  
M. H. Swaminath ◽  
H. C. Poornesha ◽  
Rashmi Bhat ◽  
R. Raghunath
Keyword(s):  
Asian Elephant ◽  
Southern India ◽  
Elephant Population

Population size estimation of an Asian elephant population in eastern Cambodia through non-invasive mark-recapture sampling

2014 ◽  
Vol 15 (4) ◽  
pp. 803-810 ◽  
Author(s):  
Thomas N. E. Gray ◽  
T. N. C. Vidya ◽  
Sheetal Potdar ◽  
D. K. Bharti ◽  
Prum Sovanna
Keyword(s):  
Population Size ◽  
Population Size Estimation ◽  
Asian Elephant ◽  
Size Estimation ◽  
Mark Recapture ◽  
Non Invasive ◽  
Elephant Population

scholarly journals Effects of Male Age and Female Presence on Male Associations in a Large, Polygynous Mammal in Southern India: The Asian Elephant

2021 ◽  
Vol 9 ◽  
Author(s):  
P. Keerthipriya ◽  
S. Nandini ◽  
T. N. C. Vidya
Keyword(s):  
Social Learning ◽  
Social Organization ◽  
Asian Elephant ◽  
Southern India ◽  
Older Individuals ◽  
Adult Males ◽  
Young Males ◽  
Male Age ◽  
Study Population ◽  
Female Presence

We present a detailed study of male associations in the Asian elephant, using 6 years of data on identified, non-musth males. Adult males spent greater proportions of their time solitarily than in mixed-sex or in all-male groups. Old (over 30 years) males were sighted more frequently with their age-peers and less frequently with young (15–30 years) males than expected at random in all-male groups. Young males were not sighted more frequently with old males than with young males, and did not disproportionately initiate associations with old males. These results suggest that male associations, in the absence of females, may allow for old non-musth males to test strengths against age-peers. Social learning from older individuals did not seem to be important in male associations, unlike that observed in the African savannah elephant. We also found a constraint on the sizes of all-male groups, similar to that seen in female groups in our study population, and all-male groups were rarer and smaller than those in African savannah elephant. Although male associations were weak, most males had a significant top associate, with whom their association was the strongest, in female absence. In mixed-sex groups, male associations occurred at random, suggesting that males were tracking female groups independently. Differences in male social organization from that of the related African savannah elephant that occupies a similar niche possibly arise from differences in ecology.

scholarly journals A Quantitative Genetic Analysis of Nuclear-Cytoplasmic Male Sterility in Structured Populations of Silene vulgaris

Genetics ◽  
2001 ◽  
Vol 158 (2) ◽  
pp. 833-841 ◽  
Author(s):  
Douglas R Taylor ◽  
Matthew S Olson ◽  
David E McCauley
Keyword(s):  
Population Structure ◽  
Sex Ratio ◽  
Genetic Analysis ◽  
Cytoplasmic Male Sterility ◽  
Male Sterility ◽  
Sex Expression ◽  
Silene Vulgaris ◽  
Population Variance ◽  
Quantitative Genetic ◽  
Quantitative Genetic Analysis

Abstract Gynodioecy, the coexistence of functionally female and hermaphroditic morphs within plant populations, often has a complicated genetic basis involving several cytoplasmic male-sterility factors and nuclear restorers. This complexity has made it difficult to study the genetics and evolution of gynodioecy in natural populations. We use a quantitative genetic analysis of crosses within and among populations of Silene vulgaris to partition genetic variance for sex expression into nuclear and cytoplasmic components. We also use mitochondrial markers to determine whether cytoplasmic effects on sex expression can be traced to mitochondrial variance. Cytoplasmic variation and epistatic interactions between nuclear and cytoplasmic loci accounted for a significant portion of the variation in sex expression among the crosses. Source population also accounted for a significant portion of the sex ratio variation. Crosses among populations greatly enhanced the dam (cytoplasmic) effect, indicating that most among-population variance was at cytoplasmic loci. This is supported by the large among-population variance in the frequency of mitochondrial haplotypes, which also accounted for a significant portion of the sex ratio variance in our data. We discuss the similarities between the population structure we observed at loci that influence sex expression and previous work on putatively neutral loci, as well as the implications this has for what mechanisms may create and maintain population structure at loci that are influenced by natural selection.

scholarly journals Can we reestablish a self-sustaining population? A case study on reintroduced Crested Ibis with population viability analysis

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Yashuai Zhang ◽  
Fang Wang ◽  
Zhenxia Cui ◽  
Min Li ◽  
Xia Li ◽  
...  
Keyword(s):  
Sex Ratio ◽  
Population Size ◽  
Carrying Capacity ◽  
Wild Population ◽  
Population Viability Analysis ◽  
Population Viability ◽  
Viability Analysis ◽  
Crested Ibis ◽  
Reintroduced Population

Abstract Background One of the most challenging tasks in wildlife conservation and management is clarifying which and how external and intrinsic factors influence wildlife demography and long-term viability. The wild population of the Crested Ibis (Nipponia nippon) has recovered to approximately 4400, and several reintroduction programs have been carried out in China, Japan and Korea. Population viability analysis on this endangered species has been limited to the wild population, showing that the long-term population growth is restricted by the carrying capacity and inbreeding. However, gaps in knowledge of the viability of the reintroduced population and its drivers in the release environment impede the identification of the most effective population-level priorities for aiding in species recovery. Methods The field monitoring data were collected from a reintroduced Crested Ibis population in Ningshan, China from 2007 to 2018. An individual-based VORTEX model (Version 10.3.5.0) was used to predict the future viability of the reintroduced population by incorporating adaptive patterns of ibis movement in relation to catastrophe frequency, mortality and sex ratio. Results The reintroduced population in Ningshan County is unlikely to go extinct in the next 50 years. The population size was estimated to be 367, and the population genetic diversity was estimated to be 0.97. Sensitivity analysis showed that population size and extinction probability were dependent on the carrying capacity and sex ratio. The carrying capacity is the main factor accounting for the population size and genetic diversity, while the sex ratio is the primary factor responsible for the population growth trend. Conclusions A viable population of the Crested Ibis can be established according to population viability analysis. Based on our results, conservation management should prioritize a balanced sex ratio, high-quality habitat and low mortality.

scholarly journals Effect of Pheromone Blend Components, Sex Ratio, and Population Size on the Mating of Cadra cautella (Lepidoptera: Pyralidae)

2020 ◽  
Vol 20 (6) ◽  
Author(s):  
Abeysinghe Mudiyanselage Prabodha Sammani ◽  
Dissanayaka Mudiyanselage Saman Kumara Dissanayaka ◽  
Leanage Kanaka Wolly Wijayaratne ◽  
William Robert Morrison
Keyword(s):  
Sex Ratio ◽  
Population Size ◽  
Management Practices ◽  
Mating Disruption ◽  
Current Knowledge ◽  
Mating Status ◽  
Cadra Cautella ◽  
Synthetic Chemicals ◽  
Population Sizes ◽  
Lepidoptera Pyralidae

Abstract The almond moth Cadra cautella (Walker), a key pest of storage facilities, is difficult to manage using synthetic chemicals. Pheromone-based management methods remain a high priority due to advantages over conventional management practices, which typically use insecticides. Cadra cautella females release a blend of pheromone including (Z, E)-9,12-tetradecadienyl acetate (ZETA) and (Z)-9-tetradecadien-1-yl acetate (ZTA). The effect of these components on mating of C. cautella and how response varies with the population density and sex ratio remain unknown. In this study, the mating status of C. cautella was studied inside mating cages under different ratios of ZETA and ZTA diluted in hexane and at different population sizes either with equal or unequal sex ratio. The lowest percentage of mated females (highest mating disruption [MD] effects), corresponding to roughly 12.5%, was produced by a 5:1 and 3.3:1 ratio of ZETA:ZTA. Populations with equal sex ratio showed the lowest percentage of mated females, at 20% and 12.5% under lower and higher density, respectively. The next lowest percentage of mated females was produced when the sex ratio was set to 1: 2 and 2:1 male:female, with just 25% and 22.5% of moths mated, respectively. This study shows that mating status of C. cautella is influenced by ZETA:ZTA ratio, sex ratio, and population size. This current knowledge would have useful implications for mating disruption programs.

scholarly journals The wildcat Felis silvestris in northern Turkey: assessment of status using camera trapping

Oryx ◽  
2011 ◽  
Vol 45 (1) ◽  
pp. 112-118 ◽  
Author(s):  
Özgün Emre Can ◽  
İrfan Kandemi̇r ◽  
İnci̇ Togan
Keyword(s):  
Population Size ◽  
Camera Traps ◽  
Sampling Effort ◽  
Felis Silvestris ◽  
Forest Patch ◽  
Western Turkey ◽  
Lack Of Information ◽  
The Status ◽  
Capture Recapture ◽  
Estimate Population Size

AbstractThe wildcat Felis silvestris is a protected species in Turkey but the lack of information on its status is an obstacle to conservation initiatives. To assess the status of the species we interviewed local forestry and wildlife personnel and conducted field surveys in selected sites in northern, eastern and western Turkey during 2000–2007. In January–May 2006 we surveyed for the wildcat using 16 passive infrared-trigged camera traps in Yaylacı k Research Forest, a 50-km2 forest patch in Yenice Forest in northern Turkey. A total sampling effort of 1,200 camera trap days over 40 km2 yielded photo-captures of eight individual wildcats over five sampling occasions. Using the software MARK to estimate population size the closed capture–recapture model M0, which assumes a constant capture probability among all occasions and individuals, best fitted the capture history data. The wildcat population size in Yaylacı k Research Forest was estimated to be 11 (confidence interval 9–23). Yenice Forest is probably one of the most important areas for the long-term conservation of the wildcat as it is the largest intact forest habitat in Turkey with little human presence, and without human settlements, and with a high diversity of prey species. However, it has been a major logging area and is not protected. The future of Yenice Forest and its wildcat population could be secured by granting this region a protection status and enforcing environmental legislation.

Sign in / Sign up

Export Citation Format

Share Document