An assessment of the applicability of dung count to estimate the wild boar population density in a forest environment

Plhal, Radim; Kamler, Jiřı́; Homolka, M.; Drimaj, Jakub

doi:10.17221/99/2013-jfs

Cited by 14 publications

(12 citation statements)

References 34 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, the negative trend of hunter populations in Europe urges an assessment of the pros and cons, of each count method, including economic and time demands, in order to define the relative best practices. We analysed three sampling methods: drive counts [10,15–18], pellet-group counts [19–23], and camera trapping ([24–26] but see [27,28]):…”

Section: Introductionmentioning

confidence: 99%

Assessing precision and requirements of three methods to estimate roe deer density

et al. 2019

View full text Add to dashboard Cite

Roe deer (Capreolus capreolus) is the most abundant cervid in Europe and, as such, has a considerable impact over several human activities. Accurate roe deer population size estimates are useful to ensure their proper management. We tested 3 methods for estimating roe deer abundance (drive counts, pellet-group counts, and camera trapping) during two consecutive years (2012 and 2013) in the Apennines (Italy) in order to assess their precision and applicability. During the study period, population density estimates were: drive counts 21.89±12.74 roe deer/km2 and pellet-group counts 18.74±2.31 roe deer/km2 in 2012; drive counts 19.32±11.12 roe deer/km2 and camera trapping 29.05±7.48 roe deer/km2 in 2013. Precision of the density estimates differed widely among the 3 methods, with coefficients of variation ranging from 12% (pellet-group counts) to 58% (drive counts). Drive counts represented the most demanding method on account of the higher number of operators involved. Pellet-group counts yielded the most precise results and required a smaller number of operators, though the sampling effort was considerable. When compared to the other two methods, camera trapping resulted in an intermediate level of precision and required the lowest sampling effort. We also discussed field protocols of each method, considering that volunteers, rather than technicians, will more likely be appointed for these tasks in the near future. For this reason, we strongly suggest that for each method managers of population density monitoring projects take into account ease of use as well as the quality of the results obtained and the resources required.

show abstract

Section: Introductionmentioning

confidence: 99%

Assessing precision and requirements of three methods to estimate roe deer density

et al. 2019

View full text Add to dashboard Cite

show abstract

“…) and has been described as one of the most accurate methods for determining abundance (Plhal et al. ). However, dung counts can be problematic in multi‐species ungulate communities due to seasonal variation of dung morphology (Alvarez ), varying encounter rates for pellets from differently sized ungulates (Lioy et al.…”

Section: Introductionmentioning

confidence: 99%

Pictures or pellets? Comparing camera trapping and dung counts as methods for estimating population densities of ungulates

Pfeffer

Spitzer

Allen

et al. 2017

Remote Sens Ecol Conserv

View full text Add to dashboard Cite

Across the northern hemisphere, land use changes and, possibly, warmer winters are leading to more abundant and diverse ungulate communities causing increased socioeconomic and ecological consequences. Reliable population estimates are crucial for sustainable management, but it is currently unclear which monitoring method is most suitable to track changes in multi-species assemblages. We compared dung counts and camera trapping as two non-invasive census methods to estimate population densities of moose Alces alces and roe deer Capreolus capreolus in Northern Sweden. For camera trapping, we tested the random encounter model (REM) which can estimate densities without the need to recognize individual animals. We evaluated different simplification options of the REM in terms of estimates of detection distance and angle (raw data vs. modelled) and of daily movement rate (camera trap based vs. telemetry based). In comparison to density estimates from camera traps, we found that, dung counts appeared to underestimate population density for roe deer, but not for moose. Estimates of detection distance and angle from modelled versus raw camera data resulted in nearly identical outcomes. The telemetry-derived daily movement rate for moose and roe deer resulted in much higher density estimates than the camera trap-derived estimates. We suggest that camera trapping may be a robust complement to dung counts when monitoring ungulate communities, particularly when similarities between dung pellets from sympatric deer species make unambiguous assignment difficult. Moreover, we show that a simplified use of the REM method holds great potential for large-scale citizen science-based programmes (e.g. involving hunters) that can track the rapidly changing European wildlife landscape. We suggest to include camera trapping in management programmes, where the analysis can be verified via web-based applications.

show abstract

“…Defecation rates could show intra-specific variation, in relation to diet, body weight, age class, activity, movement rates and season (e.g., Smith 1964;Rogers 1987;Aarnink et al 2006). Recent estimates of daily defecation rates of wild boars have been obtained from individuals in captivity (Ferretti et al 2015) or from ''outside field experiments'' (Plhal et al 2014). Mean values ranged from 3.8 to 5 faeces/individual/day (Briedermann 1986;Plhal et al 2014;Ferretti et al 2015, who provided mean and standard deviation values: 4.3 faeces/ individual/day, SD = 0.4), which may suggest a low variability of daily defecation rates in this ungulate.…”

Section: Discussionmentioning

confidence: 99%

“…Recent estimates of daily defecation rates of wild boars have been obtained from individuals in captivity (Ferretti et al 2015) or from ''outside field experiments'' (Plhal et al 2014). Mean values ranged from 3.8 to 5 faeces/individual/day (Briedermann 1986;Plhal et al 2014;Ferretti et al 2015, who provided mean and standard deviation values: 4.3 faeces/ individual/day, SD = 0.4), which may suggest a low variability of daily defecation rates in this ungulate. However, additional information is required, especially for Mediterranean areas, before applying such defecation rate values to an estimate of absolute densities.…”

Section: Discussionmentioning

confidence: 99%

“…Faeces counts are a standard method usually applied to estimate the abundance of wild deer (e.g., Neff 1968;Putman 1984;Mayle et al 1999). They may also be used to estimate indices of relative abundance of wild boar/feral pigs (Hone 1995;Hone and Martin 1998;Vicente et al 2004;Acevedo et al 2007;Plhal et al 2014) and their relationship with wild boar density has been shown (Hone 2012). Counts based on prior clearance of faeces in sampling plots have been recommended (Hone and Martin 1998;Engeman et al 2013), especially in areas where decay rates of faeces is fast and highly variable among habitats and months (e.g., in the Mediterranean area, Massei et al 1998;Minder 2006).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

The use of faeces counts to estimate relative densities of wild boar in a Mediterranean area

Ferretti

Fattorini

Sforzi³

et al. 2016

Population Ecology

View full text Add to dashboard Cite

The monitoring of population trends of wild ungulates is important to evaluate their population dynamics and to develop sound conservation/management plans. The wild boar Sus scrofa can impose heavy impacts on ecosytems and human activities, as well as be responsible for disease transmission. Estimating abundance of wild boars is a challenging issue, because of some peculiar biological and ecological traits of this ungulate. Indices of relative abundance could be used to evaluate its population trends. In a Mediterranean area we used faeces counts, through a two-stage stratified sampling, to estimate relative densities of wild boars, between 2007 and 2014. Faeces density estimates increased not significantly between 2007 (151.5 faeces/100 ha) and 2010 (203.8 faeces/100 ha) and decreased significantly from 2010 to 2014 (95.5 faeces/100 ha). The decrease in faeces density estimates was consistent with the increased harvest effort (number of harvest days), performed from 2010 to 2013 to limit impact on ecosystems and reduce damages to crops. The variation of faeces density estimates was also consistent with that of harvest indices (total harvest to harvest effort), with significantly positive values of Pearson and rank correlation coefficients. Results suggest that faeces density estimates achieved with the adopted sampling strategies can be effectively used as indices of relative abundance

show abstract

An assessment of the applicability of dung count to estimate the wild boar population density in a forest environment

Cited by 14 publications

References 34 publications

Assessing precision and requirements of three methods to estimate roe deer density

Assessing precision and requirements of three methods to estimate roe deer density

Pictures or pellets? Comparing camera trapping and dung counts as methods for estimating population densities of ungulates

The use of faeces counts to estimate relative densities of wild boar in a Mediterranean area

Contact Info

Product

Resources

About