Feral pigs in north-western Australia: population recovery after 1080 baiting and further control

2006 ◽  
Vol 33 (5) ◽  
pp. 417 ◽  
Author(s):  
Laurie E. Twigg ◽  
Tim Lowe ◽  
Michael Everett ◽  
Gary Martin
Keyword(s):  
Western Australia ◽  
Population Recovery ◽  
Feral Pigs ◽  
Muddy Water ◽  
Good Body Condition ◽  
Bait Station ◽  
Before And After ◽  
Bait Stations ◽  
North Western ◽  
Fitzroy River

The recovery rate of a population of feral pigs (Sus scrofa) in the west Kimberley in north-western Australia was determined 12 months after a 1080 (sodium fluoroacetate)-baiting program. An estimated 56 pigs were present in the 15 000-ha study area in August 2005 compared with the prebaiting levels of 250–275 pigs in 2004 (11 pigs were known to be alive on site after the 2004 baiting). This represents a population recovery of 20–23% of the 2004 prebaiting levels. Although most pigs were in good body condition, environmental conditions were quite different between the two years. In 2005, some waterholes were dry or comprised mainly muddy water with little associated shelter for feral pigs. Consequently, and in contrast to 2004, no pigs were seen, and no bait take could be attributed to feral pigs, at the four resurveyed waterholes. Most pig sightings, and activity, were close to the Fitzroy River. Fermented wheat, with blood and bone, was used to determine areas of pig activity, and also used as prefeed before 1080-baiting commenced in 2005. Using the same bait stations as for 2004, plus additional stations established in new areas of pig activity, 1080-treated wheat and malted barley again proved highly effective in reducing pig numbers. The daily sighting index before and after 1080-baiting indicated that pig numbers had been reduced by ~90% within four days. Estimated pre- and postpoisoning density, with and without an edge effect, was 0.12–1.7 pigs km–2 and 0.05–0.67 pigs km–2. Pig tracks decreased to zero on the six track plots within two days of baiting, but the number of macropod tracks remained constant over the four-day baiting period. Thirty-eight poisoned pigs were found after 1080-baiting, and these were generally in clustered groups within 200 m of an active bait station. Poisoned juvenile pigs were again found closer to the active bait stations than were adult or subadult pigs (P < 0.05).

Feral pigs in north-western Australia: basic biology, bait consumption, and the efficacy of 1080 baits

2005 ◽  
Vol 32 (4) ◽  
pp. 281 ◽  
Author(s):  
Laurie E. Twigg ◽  
Tim Lowe ◽  
Gary Martin ◽  
Michael Everett
Keyword(s):  
Western Australia ◽  
Management Strategies ◽  
Feral Pigs ◽  
River Region ◽  
Before And After ◽  
Poison Baiting ◽  
Basic Biology ◽  
Bait Stations ◽  
North Western

Bait consumption, and the efficacy of 1080-treated grain, were determined for feral pigs (Sus scrofa) during the dry season in the Fitzroy River region of north-western Australia. There were an estimated 250 pigs on the study site (15 000-ha paddock with beef cattle) before poison-baiting, and group size and the basic biology of these pigs were similar to that found elsewhere in Australia. All animals at the study site were naive to the test baits. Fermented wheat with added blood and bone was an attractant for feral pigs but added fish oil was not. Wheat and malted barley were the ‘preferred’ baits. Lupins and pig pellets were consumed in lesser amounts, suggesting that they are less/not acceptable to some feral pigs. Consequently, the efficacy of 1080-treated wheat and malted barley was determined (n = 3 sites per treatment). Three independent measures of pig activity/abundance were used. The daily sighting index before and after poison-baiting suggested that pig numbers were decreased by at least 81–100% (mean 89%) regardless of which bait was used. The take of both 1080-bait and non-toxic fermented wheat added to each station generally ceased within 1–3 days, and little take occurred during the post-poisoning follow-up. Pig tracks decreased to zero within 1–3 days of poisoning on the two sites where track plots were established. However, due to the arrival of ‘immigrant’ pigs ~6 days after poisoning on two sites, and the need to close down a third site before poison-baiting could be completed, we believe the absolute efficacy was greater than the 89% overall reduction. Even though they had access to bait, there was no bait-take by non-target species, either native (toxic and non-toxic bait) or domestic (non-toxic bait). The 61 pig carcases found after poisoning were within 20–610 m of active bait stations (mean 232 m), and most were found in clustered groups. These findings are discussed with respect to the development of management strategies for reducing the impacts of feral pigs, and in terms of their potential implications for developing wildlife disease (exotic and endemic) contingency plans.

Bait consumption by, and 1080-based control of, feral pigs in the Mediterranean climatic region of south-western Australia

2007 ◽  
Vol 34 (2) ◽  
pp. 125 ◽  
Author(s):  
Laurie E. Twigg ◽  
Tim Lowe ◽  
Gary Martin
Keyword(s):  
Western Australia ◽  
Sus Scrofa ◽  
Native Species ◽  
Target Species ◽  
Variable Response ◽  
Feral Pigs ◽  
Poison Baiting ◽  
The Mediterranean ◽  
Bait Stations ◽  
Minimal Evidence

The consumption of five non-toxic, grain-based baits, and the effectiveness of the preferred baits when treated with 1080 in reducing pig numbers, were determined for feral pigs (Sus scrofa) in several areas in the Mediterranean agricultural region of Western Australia. Fermented wheat with added blood and bone proved an effective attractant for feral pigs, and for determining areas of pig activity. Wheat and malted barley were the preferred baits, there was a variable response to lupins, and commercial pig pellets were consumed least. Malted barley, barley, and wheat treated with 1080 gave good reductions in pig numbers at the localised scale. Where pigs would eat lupins, 1080-treated lupins were usually effective in reducing pig abundance. In some instances, further evidence of feral pig activity was not seen on several sites for several months after poison-baiting occurred. The addition of a small amount of unpoisoned grain to mask the presence of 1080 did not increase the take of treated bait (P < 0.05). Although finding poisoned pigs was difficult owing to the terrain and the presence of bush remnants, the poisoned pigs found (n = 90) were often within 200 m of active bait stations. 1080-poisoned pigs included both adult (≥25 kg) and non-adult pigs of both sexes. Body mass of these pigs ranged from 4 to 90 kg. In all, 42% of poisoned adults found (n = 50) were 50 kg or more. There was minimal evidence of bait take by non-target species, and, where this occurred, it generally involved the consumption of the fermented wheat attractant by kangaroos (Macropus spp.) and foxes (Vulpes vulpes). Six foxes were known to have been poisoned with 1080-treated grain (4 with malted barley, 2 with wheat). Excluding foxes, no other non-target animals, including native species, were found dead during the intensive searches for poisoned pigs.

Evaluation of bait stations for broadacre control of rabbits

2002 ◽  
Vol 29 (5) ◽  
pp. 513 ◽  
Author(s):  
Laurie E. Twigg ◽  
Tim J. Lowe ◽  
Gary R. Martin
Keyword(s):  
Western Australia ◽  
Weed Species ◽  
Experimental Control ◽  
Agricultural Region ◽  
Before And After ◽  
Pre Treatment ◽  
The Cost ◽  
Bait Stations ◽  
Free Ranging

The efficacy of bait stations (200-L drum cut in half longitudinally) for the broadacre control of rabbits was compared with that obtained with standard trail-baiting procedures in the southern agricultural region of Western Australia. Bait stations were tested with and without the provision of pre-feed. The bait used was 1.0% 1080 One-shot oats, and corresponding experimental control sites were treated with unpoisoned oats. On the basis of spotlight counts before and after baiting, the reduction in rabbit numbers obtained with bait stations in the absence of pre-feed was poor, with a mean reduction of only 27% within 14 days. These reductions did not improve appreciably where sites were monitored for a further 28 days (i.e. 42 days in total). In contrast, the provision of pre-feed for 21 days prior to adding the 1080 bait resulted in a mean reduction in rabbit numbers of 57% within 14 days after the poisoned bait was added. However, the greatest reductions in rabbit numbers were achieved with trail baiting, where, relative to pre-treatment counts, rabbit numbers were reduced by 72% at Day 7 and by 84% at Day 14. The oats used to manufacture the 1080 One-shot product are subjected to gamma-sterilisation to prevent the germination of the oats, and any associated seeds of weed species. When offered a choice (matched sets), there was no difference in the amount of non-toxic gamma-sterilised oats and unsterilised oats consumed by free-ranging wild rabbits. On the basis of the costs incurred during the trials, trail baiting was by far the cheapest option for the broadacre control of rabbits. However, the cost of using bait stations would be discounted to some degree once these stations are able to be reused. The cost of trail baiting to protect a 15-ha 'border' of crop was $157 and $113 for three and two parallel trails (6 kg km–1 trail–1), respectively.

scholarly journals Large‐scale eDNA metabarcoding survey reveals marine biogeographic break and transitions over tropical north‐western Australia

2021 ◽  
Author(s):  
Katrina West ◽  
Michael J. Travers ◽  
Michael Stat ◽  
Euan S. Harvey ◽  
Zoe T. Richards ◽  
...  
Keyword(s):  
Western Australia ◽  
Large Scale ◽  
North Western

scholarly journals The effect of COVID19 pandemic restrictions on an urban rodent population

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Miguel A. Bedoya-Pérez ◽  
Michael P. Ward ◽  
Max Loomes ◽  
Iain S. McGregor ◽  
Mathew S. Crowther
Keyword(s):  
Binary Data ◽  
Sampling Interval ◽  
Resource Scarcity ◽  
Health Authorities ◽  
Before And After ◽  
Directional Change ◽  
Public Health Authorities ◽  
Bait Stations ◽  
Rodent Populations ◽  
The City

AbstractShortly after the enactment of restrictions aimed at limiting the spread of COVID-19, various local government and public health authorities around the world reported an increased sighting of rats. Such reports have yet to be empirically validated. Here we combined data from multi-catch rodent stations (providing data on rodent captures), rodent bait stations (providing data on rodent activity) and residents’ complaints to explore the effects of a six week lockdown period on rodent populations within the City of Sydney, Australia. The sampling interval encompassed October 2019 to July 2020 with lockdown defined as the interval from April 1st to May 15th, 2020. Rodent captures and activity (visits to bait stations) were stable prior to lockdown. Captures showed a rapid increase and then decline during the lockdown, while rodent visits to bait stations declined throughout this period. There were no changes in the frequency of complaints during lockdown relative to before and after lockdown. There was a non-directional change in the geographical distribution of indices of rodent abundance suggesting that rodents redistributed in response to resource scarcity. We hypothesize that lockdown measures initially resulted in increased rodent captures due to sudden shortage of human-derived food resources. Rodent visits to bait stations might not show this pattern due to the nature of the binary data collected, namely the presence or absence of a visit. Relocation of bait stations driven by pest management goals may also have affected the detection of any directional spatial effect. We conclude that the onset of COVID-19 may have disrupted commensal rodent populations, with possible implications for the future management of these ubiquitous urban indicator species.

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