Bayesian modelling reveals differences in long-term trends in the harvest of native and introduced species by recreational hunters in Australia

Abstract

Context Little is known about wildlife harvesting by licensed recreational hunters in Australia, where both native and introduced species are hunted. It is important to understand harvest trends to assess sustainability for native species and implications for population control of introduced species. Aim The aim of this study was to analyse trends in hunter participation, activity and efficiency, and wildlife harvest, including effects of climate, in Victoria, Australia, for three game species groups: introduced deer, native waterfowl (ducks) and one native grassland species, stubble quail (Coturnix pectoralis). Methods Telephone surveys of a random sample of licenced Victorian hunters were performed annually from 2009 to 2019. Hunters were asked to quantify their hunting effort and the number of animals harvested. The respondents’ answers were analysed to estimate measures of hunter success, activity and efficiency. Bayesian modelling was applied to these data, accounting for changes over time, differences between survey periods for all licence types, and random effects for over-dispersion. The effect of climate on game bird hunter activity and harvest was estimated, as measured by the El Niño-Southern Oscillation (ENSO). Results Over 11 years, annual deer harvest (all species) increased exponentially, at a mean annual rate of 17% (95% credible interval: 14–21%), and the number of deer hunters increased at 8% (5–11%). In contrast, for ducks and stubble quail, hunter numbers remained relatively unchanged, with no evidence of consistent change to total harvests over time, unrelated to changes in environmental conditions or regulations. The annual duck harvest was influenced by ENSO and hunting regulations. The annual stubble quail harvest exhibited ‘boom-and-bust’ dynamics, with an exceptionally large harvest immediately after a La Niña season. Conclusions Long-term monitoring of harvest trends in south-eastern Australia revealed stark differences between introduced deer and native birds: harvest of deer increased rapidly whereas equivalent rates for game birds were either stable or declining. Seasonal effects had a strong influence on game bird harvest. Environmental and regulatory conditions were influential for harvest outcomes for ducks and stubble quail. Implications This study filled a key knowledge gap around managing harvesting of game species, but increased scrutiny is warranted in this field.

Assessing the efficacy of electronic quail callers in attracting stubble quail and non-target predators

“…bust abundance cycles [34] with a regular spring/early-summer breeding period and frequent second breeding known to occur in late-summer/autumn if conditions are favourable [28,35]. Little is known of their social organisation or behaviour in the wild, including their breeding behaviour, and whether they establish territories, including during the breeding period [29].…”

“…The stubble quail is the only native ground bird that can be hunted in the south-eastern Australian states of Victoria and South Australia [26]. In Victoria, they are hunted using shotguns and gundogs [26], mostly on privately owned agricultural land where cropping or grazing is the primary land use and have been hunted in this way for over 100 years [34,36]. In Victoria, the stubble quail hunting season extends from the first Saturday in April to the end of June, inclusive, each year (the hunting season) [34], with a strict daily bag limit (20 birds per hunter per day).…”

“…There are no sex-based restrictions within this. Total seasonal harvests can vary from the tens of thousands to the hundreds of thousands as populations fluctuate in response to seasonal conditions [34,37].…”

“…This likely makes 'quail callers' attractive to hunters as a tool to increase harvest success, although the relationship between hunter success rates, and frequency of hunting trips (i.e. hunting effort) [34], and 'quail caller' use remains unknown. Based on the findings in this study, there is the real possibility that 'quail callers' could increase the ability for less skilled hunters or those who hunt without dogs to increase their effectiveness and subsequent harvest.…”

Lead ammunition residues in a hunted Australian grassland bird, the stubble quail (Coturnix pectoralis): Implications for human and wildlife health

“…They are commonly harvested using shotguns and gundogs on privately owned agricultural land where cropping is the primary land use ( Fig 1 ), and public lands (game reserves), and have been hunted in this way for over 100 years [ 27 ]. Currently, approximately 200,000 stubble quail are harvested each year in Victoria by approximately 28,000 licenced hunters [ 28 ], all are destined for human consumption, and most are hunted with lead shot. While lead shot has been banned for waterfowl hunting in many (but not all) Australian jurisdictions, its use remains legal for non-waterbirds including grassland birds [ 25 ], notably the stubble quail.…”