Dingo baiting did not reduce fetal/calf loss in beef cattle in northern South Australia

Abstract

Beef cattle production is the major agricultural pursuit in the arid rangelands of Australia. Dingo predation is often considered a significant threat to production in rangeland beef herds, but there is a need for improved understanding of the effects of dingo baiting on reproductive wastage. We experimentally compared fetal/calf loss on baited and non-baited treatment areas within three northern South Australian beef herds over a 2–4-year period. At re-musters, lactation was used to determine the outcomes of known pregnancies. Potential explanatory factors for fetal/calf loss (dingo baiting, dingo activity, summer heat, cow age, seasonal conditions, activity of dingo prey and selected livestock diseases) were investigated. From 3145 tracked pregnancies, fetal/calf loss averaged 18.6%, with no overall significant effect of baiting. Fetal/calf loss averaged 27.3% for primiparous (first pregnancy) heifers and 16.8% for multiparous (2nd or later calf) cows. On average, dingo-activity indices were 59.3% lower in baited treatments than in controls, although background site differences in habitat, weather and previous dingo control could have contributed to these lower indices. The overall scale and timing of fetal/calf loss was not correlated with dingo activity, time of year, a satellite-derived measure of landscape greenness (normalised difference vegetation index), or activity of alternative dingo prey. Limited blood testing suggested that successful pregnancy outcomes, especially in primiparous heifers, may have been reduced by the livestock diseases pestivirus and leptospirosis. The percentage occurrence of cattle hair in dingo scats was higher when seasonal conditions were poorer and alternative prey less common, but lack of association between fetal/calf loss and normalised difference vegetation index suggests that carrion feeding, rather than calf predation, was the more likely cause. Nevertheless, during the fair to excellent prevailing seasons, there were direct observations of calf predation. It is likely that ground baiting, as applied, was ineffective in protecting calves, or that site effects, variable cow age and disease confounded our results.

Aerial baiting and wild dog mortality in south-eastern Australia

“…Rather, a better term for this outcome and similarly low population reductions (e.g. Allen and Leung 2014;Campbell et al 2019) might be population 'disturbance'.…”

Continental patterns in the diet of a top predator: Australia's dingo

“…scavenging of carrion vs. predation), assessment of whether lethal control of dingoes actually decreases livestock losses attributed to dingoes (Allen , , Campbell et al. ), and evaluation of the net effects of dingoes on pastoral production (Prowse et al. ).…”

Animal welfare considerations for using large carnivores and guardian dogs as vertebrate biocontrol tools against other animals

“…Other techniques, such as exclusion fencing (de Tores and Marlow, 2011;Allen and West, 2013) and guardian animals (Potgieter et al, 2013;Linnell and Lescureux, 2015;Allen et al, 2016), operate in both lethal and nonlethal ways. All wildlife control tools are typically applied against a select number of target species within multi-predator multi-prey systems, sometimes producing variable and uncertain outcomes (Treves et al, 2016;Lennox et al, 2018;van Eeden et al, 2018;Campbell et al, 2019).…”

“…But while such traditional tools have often been subject to intense and repeated formal assessment of their efficacy (e.g. Eldridge et al, 2002;Campbell et al, 2019) and welfare impacts (e.g. Fleming et al, 1998;Marks et al, 2004;Meek et al, 2019;Allen et al, In press), to date there has been very little consideration of the animal welfare implications of deliberately using predation and/or fear of predation as a wildlife management tool (Allen et al, 2017).…”