The Effectiveness of Hunting Dogs for Removing Feral Pigs (Sus Scrofa).

1995 ◽  
Vol 22 (2) ◽  
pp. 147 ◽  
Author(s):  
P Caley ◽  
B Ottley

The effectiveness of a small team of hunting dogs for removing feral pigs was examined in relation to group size of feral pigs encountered and the population density of pigs being hunted. Hunting dogs were successful on 88% of occasions of catching or cornering solitary pigs when encountered. This rate of success rapidly declined as the group size of encountered pigs increased, with the mean maximum number of pigs that could be caught or cornered in any one encounter estimated to be about one pig per dog. The sex ratio of mature pigs obtained from a hunted sample showed a significant bias ( X*2 = 4.3,d.f. = 1, P< 0.05) towards catching more males (M: F = 1.6: 1.0). One team of hunting dogs removed 22 of an estimated 79 pigs inhabiting a 94-km*2 area at a rate of 0.6 pigs h-*1 in 35 h of hunting. It is concluded that hunting with dogs is an effective way for removing residual pigs after densities have been reduced by other forms of control.

2013 ◽  
Vol 21 (1) ◽  
pp. 25-30 ◽  
Author(s):  
JB Karki ◽  
BB Thapa

A survey of blue sheep (Pseudois nayaur) was conducted in six blocks of Dhorpatan Hunting Reserve (DHR), Nepal. A total of 852 blue sheep were recorded in 73 different groups. The average group size was found to be 11.7 individuals. The average population density of blue sheep in the reserve was found to be 1.28 animals per km2. There were 263 rams, 307 ewes, 89 yearlings and 39 lambs. Among the rams, 126 were classified as trophy rams, 92 as medium rams and 45 as young rams. The ratio of trophy rams to other rams was found to be higher than those found in the earlier studies. The mean sex ratio was 86 males per 100 females and the yearling to ewes ratio was 29 per 100 ewes. The survey of Himalayan tahr (Hemitragus jemlahicus) in Sundaha block recorded 53 individuals with 30 males, 14 females, eight yearlings, and one lamb. The results indicated that the existing quota of blue sheep hunting can be safely continued. In case of higher demands, two more quotas can be added to Barse, Dogadi and Sundaha blocks for the next five years (2008-2012). Himalayan tahrs can be hunted in all the blocks. Sundaha block can sustain four while the rest of the blocks can sustain two Himalayan tahrs per year. DOI: http://dx.doi.org/10.3126/banko.v21i1.9060 Banko Janakari, Vol. 21, No. 1 2011; 25-30


1989 ◽  
Vol 16 (2) ◽  
pp. 195 ◽  
Author(s):  
JC Mcilroy ◽  
M Braysher ◽  
GA Saunders

The aim of this study was to develop better techniques for controlling feral pigs, Sus scrofa, in the event of an outbreak of an exotic disease than the use of 1080. Trail-baiting with warfarin-treated wheat killed 30 of 32 feral pigs carrying radio transmitters in Namadgi National Park, A.C.T., in May 1986. The casualties took 9.7 � 0.4 (mean � s.e.) days to die (range 6-14) and all died within 2.06 km of the bait trail. The two survivors (both males) were radio-located within 339 m of the poison trails several times, but then moved 5.1 and 1.5 km, respectively, out of the trial area. Home ranges averaged 4.7 � 0.6 km2 (range 0.7-22.6) and the population density was approximately 2 km-2. The pigs' mobility did not alter as death approached. They moved equal distances during the day and the night. Differences in mobility between the sexes were generally minor.


1992 ◽  
Vol 70 (8) ◽  
pp. 1632-1635 ◽  
Author(s):  
Pierre-Yves Quenette ◽  
Jean-François Gerard

Vigilance behaviour of captive wild boars at feeding points was investigated using films. Results show that individual vigilance decreased with increasing group size, especially between solitary individuals and groups of 2. Moreover, the collective vigilance was, whatever the group size, below the individual vigilance in solitary animals. The study of the motor variability of vigilance behaviour allows three types of movement to be distinguished. The mean durations of each type vary largely, but are almost constant whatever the group size. On the other hand, the relative proportions of the vigilance acts change according to group size. Although previous studies of vigilance are in keeping with the functional approach of behaviour, these data are interpreted in terms of proximate causation. A mechanism based on allelomimesis is proposed to explain the results.


1993 ◽  
Vol 20 (5) ◽  
pp. 625 ◽  
Author(s):  
P Caley

Employed mark-recapture techniques to monitor trends in the population density of feral pigs in a tropical woodland habitat containing cereal crops, and compared density indices in this habitat with other similar habitat not containing cereal crops. Over the duration of this study there was no significant trend for increase or decrease but population density fluctuated seasonally between 2.2 and 3.5 pigs kg-2 in the woodland site containing cereal crops. A numerical response model was developed relating observed exponential rate of increase of feral pigs to antecedent rainfall. The model estimated the maximum exponential rate of increase (rmax) of feral pigs to be 0.065 plus or minus 0.17 (s.e.) month-1 or 0.78 plus or minus 0.21 (s.e.) year-1. Comparison of indices of population density of feral pigs in woodland habitat with cereal crops and similar woodland habitat without cereal crops demonstrated that the presence of intensive cereal cropping increased population density of feral pigs almost 4-fold. Population density in the woodland habitat without cereal crops was estimated to be 0.8 pigs kg-2. The response to rainfall and the variation in density in response to an increase in the amount of available food is interpreted as evidence that feral pig populations are limited primarily by food availability.


2016 ◽  
Vol 8 (14) ◽  
pp. 9638 ◽  
Author(s):  
Mohan Aryal ◽  
Saroj Panthi ◽  
Manoj Bhatta ◽  
Thakur Prasad Magrati ◽  
Ashok Kumar Shrestha ◽  
...  

The status and conservation of the Blue Bull Boselaphus tragocamelus is becoming one of the prominent discourses of wildlife research.  The study was carried out along the Tinau River at Rupandehi District in western Nepal to ascertain the population status, distribution and potential threats to the Blue Bull.  The study was conducted along six transect lines in the forest.  A total of 40 Blue Bulls were recorded in different transects.  The average group size was five.  The average population density was 0.228 Blue Bulls per ha and the sex ratio was 1 male: 3 females.  The potential threats of the Blue Bull along the Tinau River were habitat destruction, overgrazing, conflict, flooding and accident.  


1991 ◽  
Vol 18 (1) ◽  
pp. 49 ◽  
Author(s):  
G Saunders ◽  
B Kay

This study describes the movements of feral pigs at Sunny Corner in eastern New South Wales. Population density at this site was 2 pigs km-2. Twenty-two pigs (12 males and 10 females) were captured and fitted with telemetry transmitters. Aggregate home range for males (10.7 � 6.9 km2) was significantly greater than for females (4.9 � 1.4 km2) as was 24 h home range (1.4� 1.1 km2, males and 0.8 � 0.4 km2, females). Seasonal home ranges were greatest in the winter and smallest in the autumn. These differences were attributed to variations in food availability. During all seasons there was a preference for creeklines that had vegetative cover. This was the result of thermoregulatory needs, refuge availability and food supply. Peak activity throughout the study occurred between 1900 and 2400 hours with little movement during the middle of the day. The implications of these results to management programs are discussed.


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.


1991 ◽  
Vol 65 (03) ◽  
pp. 263-267 ◽  
Author(s):  
A M H P van den Besselaar ◽  
R M Bertina

SummaryIn a collaborative trial of eleven laboratories which was performed mainly within the framework of the European Community Bureau of Reference (BCR), a second reference material for thromboplastin, rabbit, plain, was calibrated against its predecessor RBT/79. This second reference material (coded CRM 149R) has a mean International Sensitivity Index (ISI) of 1.343 with a standard error of the mean of 0.035. The standard error of the ISI was determined by combination of the standard errors of the ISI of RBT/79 and the slope of the calibration line in this trial.The BCR reference material for thromboplastin, human, plain (coded BCT/099) was also included in this trial for assessment of the long-term stability of the relationship with RBT/79. The results indicated that this relationship has not changed over a period of 8 years. The interlaboratory variation of the slope of the relationship between CRM 149R and RBT/79 was significantly lower than the variation of the slope of the relationship between BCT/099 and RBT/79. In addition to the manual technique, a semi-automatic coagulometer according to Schnitger & Gross was used to determine prothrombin times with CRM 149R. The mean ISI of CRM 149R was not affected by replacement of the manual technique by this particular coagulometer.Two lyophilized plasmas were included in this trial. The mean slope of relationship between RBT/79 and CRM 149R based on the two lyophilized plasmas was the same as the corresponding slope based on fresh plasmas. Tlowever, the mean slope of relationship between RBT/79 and BCT/099 based on the two lyophilized plasmas was 4.9% higher than the mean slope based on fresh plasmas. Thus, the use of these lyophilized plasmas induced a small but significant bias in the slope of relationship between these thromboplastins of different species.


2021 ◽  
Author(s):  
Konrad Lipkowski ◽  
Sophie Steigerwald ◽  
Lisa M Schulte ◽  
Carolin Sommer-Trembo ◽  
Jonas Jourdan

Abstract The extent of male mate choosiness is driven by a trade-off between various environmental factors associated with the costs of mate acquisition, quality assessment and opportunity costs. Our knowledge about natural variation in male mate choosiness across different populations of the same species, however, remains limited. In this study, we compared male mate choosiness across 10 natural populations of the freshwater amphipod Gammarus roeselii (Gervais 1835), a species with overall high male mating investments, and evaluated the relative influence of population density and sex ratio (both affecting mate availability) on male mate choosiness. We investigated amplexus establishment after separating mating pairs and presenting focal males with a novel, size-matched female from the same population. Our analysis revealed considerable effects of sex ratio and (to a lesser extent) population density on time until amplexus establishment (choosiness). Male amphipods are able to perceive variable social conditions (e.g., sex ratio) and modify their mating strategy accordingly: We found choosiness to be reduced in increasingly male-biased populations, whereas selectivity increases when sex ratio becomes female biased. With this, our study expands our limited knowledge on natural variations in male mate choosiness and illustrates the importance of sex ratio (i.e., level of competition) for male mating decisions in natural environments. Accounting for variation in sex ratios, therefore, allows envisioning a distinctive variation of choosiness in natural populations and highlights the importance of considering social background information in future behavioral studies.


1970 ◽  
Vol 6 (1) ◽  
pp. 45-51 ◽  
Author(s):  
T Farjana ◽  
KR Islam ◽  
MMH Mondal

 A study was conducted to investigate the population density of helminth parasites in domestic ducks (Anas boschas domesticus) in relation to host's age, sex, breed and seasons of the year from March 2002 to May 2003. A total of 300 ducks were collected from different villages of Netrokona and Mymensingh districts of Bangladesh and autopsied to collect the parasites and counted to determine the population density of parasites. Off 300 ducks examined, 290 (96.66%) were infected with 17 species of helminth parasites in which 11 species were trematodes, 4 were cestodes and 2 nematodes. Among the parasites, density of cestodes was the highest (33.15±5.26), followed by trematodes (5.98±1.32); and nematodes (2.95±0.68). Mean density of parasites increased with the increase of age (young: 21.23±1.09, adult: 26.18±2.14 and old: 27.87±2.98) while the mean density of most of the helminth parasites was higher in female ducks (31.35±4.72) than in males (27.52±3.32). Indigenous ducks (33.72±3.61) were infected with the highest load of helminths than Khaki Campbell breed (29.61±4.32) of ducks. Mean density of most trematodes (5.42±0.80) were highest in winter season whereas mean density of all cestodes (48.43±4.85) and nematodes (4.13±1.76) were highest in summer.  The present study suggests that age, sex, breed of ducks and seasons of the year influence the parasitic infection to a greater extend. Key words: Population density, helminths, duck, Bangladesh DOI = 10.3329/bjvm.v6i1.1338 Bangl. J. Vet. Med. (2008). 6 (1): 45-51


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