Population density and distribution of common warthog (<i>Phacochoerus africanus</i>Gmelin, 1788) in Dabena Valley Forest, Western Ethiopia

Edossa, Alemayehu; Bekele, Afework; Debella, Habte Jebessa

doi:10.1111/aje.13010

Cited by 2 publications

(1 citation statement)

References 34 publications

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“…In our experience, this issue is largely overlooked, and it is not uncommon for a single detection function model to be fitted across strata when stratum‐specific estimates are required. Examples in the literature include Allison and McLuckie (2018), Buuveibaatar et al (2017), Edossa et al (2022), Jefferson et al (2021), Monks et al (2021), and Strindberg et al (2020).…”

Section: Introductionmentioning

confidence: 99%

Pooling robustness in distance sampling: Avoiding bias when there is unmodelled heterogeneity

Rexstad

Buckland

Marshall

et al. 2023

Ecology and Evolution

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The pooling robustness property of distance sampling results in unbiased abundance estimation even when sources of variation in detection probability are not modeled. However, this property cannot be relied upon to produce unbiased subpopulation abundance estimates when using a single pooled detection function that ignores subpopulations. We investigate by simulation the effect of differences in subpopulation detectability upon bias in subpopulation abundance estimates. We contrast subpopulation abundance estimates using a pooled detection function with estimates derived using a detection function model employing a subpopulation covariate. Using point transect survey data from a multispecies songbird study, species‐specific abundance estimates are compared using pooled detection functions with and without a small number of adjustment terms, and a detection function with species as a covariate. With simulation, we demonstrate the bias of subpopulation abundance estimates when a pooled detection function is employed. The magnitude of the bias is positively related to the magnitude of disparity between the subpopulation detection functions. However, the abundance estimate for the entire population remains unbiased except when there is extreme heterogeneity in detection functions. Inclusion of a detection function model with a subpopulation covariate essentially removes the bias of the subpopulation abundance estimates. The analysis of the songbird point count surveys shows some bias in species‐specific abundance estimates when a pooled detection function is used. Pooling robustness is a unique property of distance sampling, producing unbiased abundance estimates at the level of the study area even in the presence of large differences in detectability between subpopulations. In situations where subpopulation abundance estimates are required for data‐poor subpopulations and where the subpopulations can be identified, we recommend the use of subpopulation as a covariate to reduce bias induced in subpopulation abundance estimates.

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Section: Introductionmentioning

confidence: 99%

Pooling robustness in distance sampling: Avoiding bias when there is unmodelled heterogeneity

Rexstad

Buckland

Marshall

et al. 2023

Ecology and Evolution

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Density of wild animal populations and their conflicts with nearby farmers in southwest Ethiopia, Mankira Forest

Asaye,

Tekalign,

Dobamo

2024

Preprint

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Farmers' survival is seriously threatened by wild animal species' coexistence and joint use of limited resources. A study on the density of wild animals and their conflicts with nearby farmers was conducted from December 2022 to May 2023 in southwest Ethiopia, Mankira Forest. Using the distance sampling technique, the densities of the wild animal population were estimated. The incidence of conflict between humans and wild animals was measured using a questionnaire given to 241 randomly selected household heads. The estimated densities of spotted hyenas (0.40 ± 0.54), Anubis baboons (11.83 ± 4.4), grivet monkeys (15.18 ± 5.12), black-backed jackals (0.60 ± 0.14), porcupines (0.70 ± 0.12), and warthogs (1.2 ± 0.20 individuals/km2) were recorded. Potatoes, wheat, and maize were the most severely damaged cereal crops. The most prevalent and top-ranked crop-raiding species was the Anubis baboon (N = 104, 43%), which was followed by the grivet monkey (N = 82), the warthog (N = 31), and the porcupine (N = 24). Depredated livestock were cattle, poultry, sheep, donkeys, dogs, horses, and mules. The spotted hyena (N = 118), black-backed jackal (N = 65), primates (N = 39), and leopard (N = 19) were the most commonly recorded predators. Various human activities that impact wildlife include deforestation, charcoal production, livestock grazing, agricultural expansion, and settlement. Guarding was the primary mitigating strategy. Locals living near forest boundaries were particularly susceptible to the impact of wild animals. Reducing livestock damage and crop loss can be achieved through continuous ecological surveying of wild animals and raising community awareness.

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Population density and distribution of common warthog (Phacochoerus africanusGmelin, 1788) in Dabena Valley Forest, Western Ethiopia

Cited by 2 publications

References 34 publications

Pooling robustness in distance sampling: Avoiding bias when there is unmodelled heterogeneity

Pooling robustness in distance sampling: Avoiding bias when there is unmodelled heterogeneity

Density of wild animal populations and their conflicts with nearby farmers in southwest Ethiopia, Mankira Forest

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