Document ID: chunk:federal_register_of_legislation:F2024L01095:body:0:p31
Version: federal_register_of_legislation:F2024L01095
Segment Type: other
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Character Range: 81193–84058

days of tracking) (Stenhouse and Moseby, 2023). For a long-lived bird this is a very high rate of mortality and suggests that reducing the rate of predation by cats and foxes increases population size.

Despite these studies being of sufficient duration to detect adult recruitment, the lack of evidence of a positive effect of fox control on Malleefowl breeding densities may be due to a number of factors: the control programs may have not sufficiently reduced foxes to benefit Malleefowl; foxes may have been effectively reduced but this may have resulted in other predators (such as feral cats) or competitors (such as mammalian herbivores) to increase and counter any net benefit to Malleefowl; or the detrimental effects of foxes on Malleefowl populations may be over-rated or be dependent on secondary factors such as an increase in resources that support high fox numbers. Further evaluation of the effectiveness of predator control on Malleefowl recovery is warranted and is of high priority to ensure that resources for Malleefowl recovery are targeted in an effective and efficient manner.

Predation on Malleefowl chicks is severe but difficult to measure in wild populations. Chicks released in mid-summer within a day of hatching have been shown to experience heavy mortality due to predation by foxes/cats, predation by raptors, and metabolic stress, in approximately equal proportions (Benshemesh 1992). Mortality was found to be greatest during the first few days and 80% of chicks were dead within ten days. Similarly, captive-reared chicks that were of various ages up to five months old and released into a small habitat remnant in autumn and winter experienced heavy (55–68%) mortality from introduced predators (predominantly foxes but also occasionally by cats) and 26–39% by raptors (Priddel and Wheeler 1994). In areas where fox abundance has been greatly reduced, juvenile Malleefowl have nonetheless suffered high mortality from raptors (Harlen and Priddel 1992). Older captive-reared Malleefowl appear less susceptible to raptors but are still highly susceptible to fox (and possibly cat) predation. At least 50% of juveniles (3–5 months old) released in autumn were thought to be killed by foxes, and a further 13% by either foxes or cats, whereas only 4% were known to have been taken by raptors (Priddel and Wheeler 1996). Predation probably accounted for an even greater proportion of juveniles than these percentages suggest as all juveniles were known to be dead within 104 days, although the cause of death could not be ascertained in nearly a quarter of cases. Sub-adult birds (14–28 months old) survived better than the younger juveniles released in the same areas, although fox predation still accounted for about 70% of birds that were released. Studies have also demonstrated that intensive fox baiting increases the survival