Quantifying efficacy of feral pig (Sus scrofa) population management

2019 ◽  
Vol 46 (7) ◽  
pp. 587 ◽  
Author(s):  
Peter J. Adams ◽  
Joseph B. Fontaine ◽  
Robert M. Huston ◽  
Patricia A. Fleming

Abstract ContextFeral pigs (Sus scrofa) are an increasing threat to agriculture and ecological communities globally. Although ground rooting is their most readily observable sign, feral pigs typically remain highly cryptic and their abundance and impacts are difficult to quantify. AimsThe aim of the present study was to evaluate the effect of current feral pig population management practices (trapping, baiting, no feral pig management) on feral pig abundance and digging impacts, using a BACI (before–after control–impact) experimental design at a landscape scale. MethodsA monitoring program was established to quantify both the abundance and digging impacts of feral pig populations within a temperate sclerophyll forest landscape using distance sampling. Transects were established across eight drinking water catchments where the whole catchment was the unit of replication for feral pig population management. Monitoring was carried out at 6-monthly intervals for 3 years, with no feral pig population management undertaken in the first year. In total, 367 feral pigs were trapped out of three catchments subject to trapping, and 26 were baited across two catchments subject to baiting with a commercial product (PIGOUT, Animal Control Technologies Australia, Melbourne, Vic., Australia). Three catchments were exempt from feral pig population management for the duration of this study. Key resultsFeral pig density within the overall study site was estimated as 1.127pigskm–2, resulting in 4580diggingskm–2year–1. There was no significant difference in feral pig density estimates observed among population management treatments or the treatment×year interaction term. An overall decrease in feral pig density across all catchments was attributed to extreme temperature and drought conditions experienced during the study. ConclusionsFeral pig populations demonstrate high resilience to current feral pig population management practices in the present study. The annual volume of soil disturbed by the numbers of feral pigs estimated across this study area is comparable to a commercial-scale resource extraction industry. We did not find significant differences in feral pig digging density among dominant vegetation types, but larger digs were associated with swamp vegetation. ImplicationsCurrent levels of feral pig population management did not reduce pig densities across eight catchments in the northern jarrah forest; therefore, more intensive population management is needed.


2015 ◽  
Vol 42 (6) ◽  
pp. 470 ◽  
Author(s):  
Jason Wishart ◽  
Steven Lapidge ◽  
Michael Braysher ◽  
Stephen D. Sarre ◽  
Jim Hone

Context Feral pigs (Sus scrofa) are a destructive invasive species that cause damage to ecologically sensitive areas. Management of biodiversity and of feral pigs assumes the diet of pigs of different ages and sexes are similar. Aims We aimed to investigate effects of feral pig age and sex on broad feral pig diet to identify potential at-risk native wildlife species so as to improve biodiversity and feral pig management. Methods Diet was determined by macroscopic analysis of the stomach content of 58 aerially shot feral pigs of mixed ages and sexes. The study occurred in the Macquarie Marshes, New South Wales, a Ramsar wetland of international significance. Results Feral pigs were largely herbivorous, with vegetable matter being found in all stomachs and contributing to a majority of the food material that was present in each stomach, by volume. Adult feral pigs had significantly more grasses and crop material in their stomachs than juveniles, while juveniles had significantly more forbs in their stomachs than adult feral pigs. Vertebrate prey items included frogs, lizard and snake, but no threatened wildlife species. Conclusions Juvenile and adult feral pigs differed in their diet, especially with regards to plant material, which has not been reported previously. There was, however, no difference in the consumption of vertebrate wildlife species between juvenile and adult, or male and female feral pigs. Slow-moving, nocturnal amphibians and reptiles were the most common vertebrate item recorded. Implications Biodiversity and feral pig management should recognise plant diet differences between demographic segments of the feral pig population. Further research is recommended to determine if diet differences also occur for threatened wildlife species, which will require more intensive nocturnal sampling.



2009 ◽  
Vol 36 (2) ◽  
pp. 110 ◽  
Author(s):  
J. Mitchell ◽  
W. Dorney ◽  
R. Mayer ◽  
J. McIlroy

The Wet Tropics bioregion of north Queensland has been identified as an area of global significance. The world-heritage-listed rainforests have been invaded by feral pigs (Sus scrofa) that are perceived to cause substantial environmental damage. A community perception exists of an annual altitudinal migration of the feral-pig population. The present study describes the movements of 29 feral pigs in relation to altitudinal migration (highland, transitional and lowland areas). Feral pigs were sedentary and stayed within their home range throughout a 4-year study period. No altitudinal migration was detected; pigs moved no more than a mean distance of 1.0 km from the centre of their calculated home ranges. There was no significant difference between the mean (±95% confidence interval) aggregate home ranges for males (8.7 ± 4.3 km2, n = 15) and females (7.2 ± 1.8 km2, n = 14). No difference in home range was detected among the three altitudinal areas: 7.2 ± 2.4 km2 for highland, 6.2 ± 3.9 km2 for transitional and 9.9 ± 5.3 km2 for lowland areas. The aggregate mean home range for all pigs in the present study was 8.0 ± 2.4 km2. The study also assessed the influence seasons had on the home range of eight feral pigs on the rainforest boundary; home ranges did not significantly vary in size between the tropical wet and dry seasons, although the mean home range in the dry season (7.7 ± 6.9 km2) was more than twice the home range in the wet season (2.9 ± 0.8 km2). Heavier pigs tended to have larger home ranges. The results of the present study suggest that feral pigs are sedentary throughout the year so broad-scale control techniques need to be applied over sufficient areas to encompass individual home ranges. Control strategies need a coordinated approach if a long-term reduction in the pig population is to be achieved.



2015 ◽  
Vol 37 (2) ◽  
pp. 194 ◽  
Author(s):  
Matthew Gentle ◽  
James Speed ◽  
Darren Marshall

Feral pigs (Sus scrofa) consume and damage crops and impact the environment through predation, competition and habitat disturbance, although supporting dietary data are lacking in agricultural landscapes. This study was undertaken to determine the relative importance of food items in the diet of feral pigs in a fragmented agricultural landscape, particularly to assist in predicting the breadth of likely impacts. Diet composition was assessed from the stomach contents of 196 feral pigs from agricultural properties in southern Queensland. Feral pigs were herbivorous, with plant matter comprising >99% of biomass consumed. Crops were consumed more frequently than non-crop species, and comprised >60% of dietary biomass, indicating a clear potential for direct economic losses. Consumption of pasture and forage species also suggests potential competition for pasture with domestic stock. There is little evidence of direct predation on native fauna, but feral pig feeding activities may impact environmental values. Seasonal differences in consumption of crop, pasture or animal food groups probably reflect the changing availability of food items. We recommend that future dietary studies examine food availability to determine any dietary preferences to assist in determining the foods most susceptible to damage. The outcomes of this study are important for developing techniques for monitoring the impacts of feral pigs, essential for developing management options to reduce feral pig damage on agricultural lands.



2014 ◽  
Vol 20 (1) ◽  
pp. 54 ◽  
Author(s):  
Steven C Hess ◽  
James D Jocobi

Hunting is often considered to be incompatible with conservation of native biota and watershed functions in Hawai‘i. Management actions for conservation generally exclude large non-native mammals from natural areas, thereby reducing the amount of land area available for hunting activities and the maintenance of sustainable game populations. An approach which may be useful in addressing the necessary minimum amount of land area allocated for hunting in Hawai‘i is to determine the amount of land area necessary for sustaining populations of hunted animals to meet current levels harvested by the public. We ask: What is the total amount of land necessary to provide sustained-yield hunting of game meat for food at the current harvest level on Hawai‘i Island if only feral pigs (Sus scrofa) were to be harvested? We used a simplistic analysis to estimate that 1 317.6 km2–1 651.4 km2 would be necessary to produce 187 333.6 kg of feral pig meat annually based on the range of dressed weight per whole pig, the proportion of a pig population that can be sustainably removed annually, and the density of pig populations in the wild. This amount of area comprises 12.6–15.8% of the total land area of Hawai‘i Island, but more likely represents 27.6–43.5% of areas that may be compatible with sustained-yield hunting.



2016 ◽  
Vol 43 (4) ◽  
pp. 277 ◽  
Author(s):  
David M. Forsyth ◽  
Robert B. Allen ◽  
Roy K. J. Allen ◽  
Kathrin Affeld ◽  
Darryl I. MacKenzie

Context Feral pigs (Sus scrofa) have a wide global distribution that includes large parts of Australia and New Zealand. There is concern about the impacts of feral pigs on above- and below-ground flora and fauna, but little is known about their habitat use and feeding activity in temperate rainforests. Aims We evaluated the importance of abiotic and biotic variables hypothesised to influence seasonal and annual feral pig habitat use and feeding activity in a montane conifer–angiosperm rainforest in Te Urewera, North Island, New Zealand. Methods We used a grid of 25 remote-camera locations to collect feral pig images in a 100-ha area during the winters and summers of 2010 and 2011. Plant composition, solar radiation and soil fertility variables were determined for each camera-image area. Multiseason, multistate occupancy models and information-theoretic methods were used to evaluate how these variables related to feral pig occupancy and feeding. Key results Feral pigs occupied more camera locations in summer than in winter, and detection probabilities increased if piglets were present and with increasing soil phosphorus (P). Piglets were detected only in summer, and their detection probability increased with increasing soil P. The probability of detecting feral pigs feeding also increased with soil P and was higher in 2010 than 2011. Conclusions Feral pigs selected locations with high soil P, probably because those sites had more food than did locations with low soil P. Mast fruiting of tawa (Beilschmiedia tawa) has been hypothesised to increase feral pig recruitment, and the higher detection probability of piglets in summer 2010 followed a heavier tawa fruit fall. Implications Our study highlighted the usefulness of camera traps and occupancy models for understanding seasonal and annual dynamics of cryptic ungulate species in remote, rugged forests, and suggests that the impacts of feral pigs will be greatest in areas of high soil P following widespread tawa masting.



1998 ◽  
Vol 25 (3) ◽  
pp. 297 ◽  
Author(s):  
J. Mitchell

This study assessed the proportion of a feral pig population that consumed aerially distributed baits incorporating a non-toxic biomarker (iophenoxic acid). Baits were distributed at a rate of 18 baits km-2 over 70 km2 of a seasonally inaccessible habitat. A total of 102 feral pigs were then captured by trapping and ground-shooting. Blood samples from 63 adult feral pigs were analysed for the presence of the biomarker; 40 (63%) were considered to have consumed at least one bait. Ground-shooting and trapping over 6 days resulted in 18% and 16% population reduction respectively.



2020 ◽  
Vol 72 (1) ◽  
Author(s):  
Melissa L. Karlin ◽  
Harun A. Khan

Abstract Feral pigs are an invasive exotic pest that damage habitat and compete with native species. Trapping feral pigs using a variety of baits or lures is the primary method for eradication, with little success. The purpose of this study was to use a variety of lures, with and without the presence of a mock corral trap, to determine if there was a preferred lure selected even in the presence of a trap. We also identified non-target species attraction to the lures, to identify a preferred choice by feral pigs that minimized these non-target species. We deployed 10 stations from July 2017 to March 2018 and used trail cameras to assess feral pig visitation frequency. The majority of feral pig visitation events occurred at the orange flavored corn without a mock corral trap present (43.20%). There was no significant difference in feral pig visitation rates to stations based on presence or absence of corral, but there were differences based on lure: orange corn had a significantly higher visitation rate than any other lure type. The plain corn station without a corral had only 15% of the feral pig visitation events, while the majority of non-target species (i.e., axis – 45.93%, white-tailed deer – 39.42%, and raccoon – 85.38% of visitation events) were associated with this bait. For these reasons, we suggest that orange flavored corn may be the better primary attractant in feral pig management activities in south Texas.



2017 ◽  
Vol 4 (03) ◽  
Author(s):  
SAMBORLANG K. WANNIANG ◽  
A. K. SINGH

A field experiment was conducted during kharif 2011 on experimental farm of the College of Post Graduate Studies (CAU–Imphal), Umiam (Meghalaya) to evaluate the effect of integration of green manuring, FYM and fertilizers as integrated nutrient management (INM) practices on growth and developmental behaviour of quality protein maize cultivar QPM 1. The data revealed that comparatively higher amount of primary nutrients were added in green manured maize plots in comparison to non green manured treatments. Green manuring also left a positive response on plant height, CGR, RGR leaf area, and dry matter accumulation in plants though the difference between green manured and non-green manured treatments was at par. Treatments 75 % RDF + 5 t FYM ha-1, 50 % RDF + 7.5 t FYM ha-1, 100 % RDF ha-1 and 75 % RDF + 2.5 t FYM ha-1 recorded significantly higher values of all the above said growth parameters over 50 % RDF + 5 t FYM ha-1 and control treatments. At all stages of observations, the maximum dry matter was associated with RDF (recommended doses of fertilizers) which was at par with 75 % RDF + 5 t FYM ha-1, but significantly higher over the plant dry weight recorded from all remaining treatments. A Significant difference in CGR at 30 – 60 and 60 – 90 DAS stage and in RGR at 90 DAS - harvest stage was observed due to various combinations of recommended dose of fertilizer with different doses of FYM. Number of days taken to attain the stages of 50% tasselling, silking and maturity did not differ significantly due to green manuring. However, treatment 75 % RDF + 5 t FYM ha-1 took significantly lesser number of days for these stages than other treatment combinations. The superiority of the treatment 75 % RDF + 5 t FYM ha-1 indicated a possibility of substituting 25% of RDF with 5 t FYM ha-1 without any loss in dry matter accumulation in plants of the quality protein hybrid maize in mid-hill ecosystems of Meghalaya.



2020 ◽  
Vol 13 (1) ◽  
pp. 208
Author(s):  
Celia De La Mora-Orozco ◽  
José G. Flores-Garnica ◽  
Lucia M. Vega-Ramírez ◽  
Irma J. González-Acuña ◽  
Juan Nápoles-Armenta ◽  
...  

The Agave tequilana Weber is an important commercial crop in the State of Jalisco, Mexico. However, the agave cultivation generates significant soil loss. For that reason, knowledge about the implementation of the agriculture management practices, such as manure application and the combination of inorganic fertilizers and manure, are relevant. The objective of this research was to determine the effect of agricultural management practices on the total organic carbon (TOC) in the soil in three study locations: Arandas, Tepatitlán, and Acatic in the Altos Sur region of Jalisco. A random sampling was carried out in each study location, 12 samples were obtained for each location at 0–30 cm deep, and a total of 36 samples were analyzed. The evaluated parameters were the potential hydrogen (pH), electrical conductivity (EC), bulk density (BD), soil-water saturation (SWS), total nitrogen (TN), and total organic carbon (TOC). Basic statistics and correlations between parameters were generated. In addition, to estimate TOC from a multivariate analysis, models were developed based on the lowest Akaike information criterion (AIC) and of the classification and regression trees (CART). ANOVA and Tukey test were determined. Results demonstrated a significant difference in the TOC percentages between the study locations. The Tukey test showed that there is no difference in TOC content between the Tepatitlán and Arandas sites, but there is a difference between these two sites and the Acatic. The latter resulted with the lowest values of TOC. Long-term studies are recommended to develop crop management strategies.



2005 ◽  
Vol 32 (7) ◽  
pp. 605 ◽  
Author(s):  
J. C. McIlroy ◽  
E. J. Gifford

Eight feral pigs (two boars, four sows and two piglets) were caught in traps using oestrous sows as lures during a control program on a remnant pig population in part of Namadgi National Park during spring, 1990. The program was mostly based on aerial baiting with warfarin. No pigs were caught in traps containing anoestrous sows or in traps containing bait only. Seven unmarked pigs (caught seven days after the cessation of baiting) did not appear to have eaten any warfarin bait. In an earlier pilot trial, two boars were caught at a trap containing an oestrous sow, one of these again in a trap baited only with fermented grain, but no pigs were caught at a trap containing an anoestrous sow. Although not cost-effective as a general technique, this method could be useful in specific circumstances, such as eradication campaigns on islands, if the last few pigs are, or have become bait shy, or are impossible to cull by other methods.



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