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The Diversity of Dingo Diets

Dingoes eat more than 200 different species of birds, mammals and reptiles, as well as fish, frogs, beetles, grasshoppers, moths and even crabs.

Dingoes eat more than 200 different species of birds, mammals and reptiles, as well as fish, frogs, beetles, grasshoppers, moths and even crabs.

By Tim Doherty

From crustaceans to camels, Australia’s top predator dines out on hundreds of vertebrate species, including threatened animals and pests.

Few species of Australian animal elicit polarised sentiments as much as the dingo. The dingo is an iconic Australian animal sitting at the top of the food chain and playing an important role in ecosystem function. As an apex predator, dingoes can regulate prey populations, with effects that filter all the way down to plants and even soils. For instance, kangaroo populations can boom when they are released from dingo predation, leading to increased herbivory and lower plant biomass. In this regard, some have referred to the dingo as Australia’s answer to the Northern Hemisphere’s grey wolf.

Although they are an important part of Australia’s eco­systems, managing dingoes is contentious because they sometimes kill livestock and threatened species. Efforts to reduce impacts on livestock involve shooting, trapping and poison baiting across much of their range.

Dingoes sometimes prey on threatened species too, and attempts to establish wild populations of endangered mammals have sometimes failed in part due to dingo predation.

This means that conflicts can emerge between the different ways that dingoes are managed. Because each of these positive and negative impacts centres around what dingoes eat, it is important that we understand how dingo diets vary between different parts of the country.

Dingoes are found across most of the mainland and on some nearshore islands. This huge distribution approaches the size of Europe, with the distance between the Australian alps and Cape York Peninsula similar to the distance between London and Athens. Thus, it is plausible to think that dingo ecology, including what they eat, might vary from one part of Australia to the next. Might dingoes from the alps prefer to dine on a hearty wombat stew, while those from warmer climes prefer a somewhat lighter lunch?

Our recent research involved the largest and most comprehensive analysis of dingo diets ever undertaken. By collating 73 studies from all over Australia examining more than 32,000 dingo scats or stomach contents, we revealed the huge range of prey species that dingoes eat and how their diet varies from one place to the next.

Dingoes eat more than 200 different species of birds, mammals and reptiles, as well as fish, frogs, beetles, grasshoppers, moths and even crabs. The most commonly occurring food types in dingo diets were large (≥ 7kg) and medium-sized (0.5–6.9 kg) mammals, followed by rabbits, small mammals (<0.5 kg), insects, reptiles, birds and introduced ungulates. However, the relative importance of these food groups in dingo diets varies depending on where in Australia they live.

In arid and semi-arid parts of Australia – the majority of the continent – dingo diets are mainly comprised of small mammals, rabbits, birds, reptiles and insects. In contrast, dingoes that live in temperate and sub-tropical eastern Australia more commonly dine on medium-sized and large mammals, including bandicoots, possums, wallabies and kangaroos. For instance, one study from the Blue Mountains found that large mammals occurred in more than 80% of dingo scats, including swamp wallabies in 29% of scats and wombats in 11%. Another study from Shoalwater Bay in Queensland recorded brushtail possums in 54% of dingo scats and bandicoots in 48%.

These patterns are broadly similar to what we found for feral cats in earlier research. The occurrence of reptiles, birds and insects in cat diets tended to be highest in arid areas, whereas medium-sized mammals were most common in feral cat diets in south-eastern Australia. The diet of introduced red foxes has not been studied at the continental scale, although a similar study from Victoria suggests that fox diets may exhibit similar patterns.

The low occurrence of medium-sized mammals in the diet of dingoes from Australia’s deserts may be due to the very high rates of mammal extinctions that have occurred there. More than 30 Australian mammal species have become extinct since European arrival, and most of these species were desert-dwellers, including the pig-footed bandicoot, lesser bilby and desert bettong. Many other species that previously covered much of the mainland now persist in tiny relictual populations, including the western quoll, brush-tailed bettong and numbat.

Medium-sized and large mammals are generally the preferred prey of dingoes, so the loss of so many species across huge parts of Australia may have resulted in large changes in what dingoes eat. Indeed, this may partly explain the high occurrence of birds, reptiles and invertebrates in dingo diets in arid Australia. These types of prey are typically smaller than medium-sized mammals, and hence less beneficial because dingoes have to catch more of them for a single meal. The “boom and bust” nature of arid Australia may also lead to dingoes eating these smaller critters more frequently because the availability of larger prey is less reliable than in wetter parts of Australia.

There is, however, one medium-sized mammal that is a major component of dingo diets in arid areas – the European rabbit. In some areas, more than 50% of dingo scats or stomachs contained the remains of this invasive species. Rabbits were introduced to Australia in the 18th century and now cover most of the continent, apart from most of the tropical north. It’s possible that native medium-sized mammals previously constituted a major part of dingo diets in arid Australia, but have since been replaced by rabbits.

Dingoes also eat sheep and cattle, and we found that the occurrence of livestock in dingo diets was most common in arid and tropical Australia, perhaps reflecting the areas where large-scale cattle grazing is most common. Even so, few studies have been conducted in areas where intensive livestock grazing occurs, so the results are likely an underestimate. Whether these dietary records equate to negative impacts on livestock production is hard to say because dietary samples are unable to distinguish between predation and scavenging, and also do not reveal instances of dingoes killing livestock without eating them.

In addition to spatial variation in prey availability, we also know that dingo diets can change over time, depending on what kinds of food are available. This includes both seasonal changes and long-term changes occurring over years and even decades. For instance, in some areas, dingoes eat reptiles most frequently in warmer months when lizards and snakes are more active.

Another study recently showed how dingoes in Victoria have increased their consumption of invasive sambar deer over the past three decades. They used hunting data to show that sambar deer abundance increased fourfold during 1984–2013, and the percentage of dingo scats containing deer increased from 0 to 8.2% over the same period.

Another recent study documented long-term changes in dingo diets in Kakadu National Park by comparing historical data from the 1980s to new data collected in 2014–15. The study found that the earlier dominance of small mammals and birds in dingo diets at Kakadu has since been replaced by large mammals such as kangaroos. This may be due to the severe declines in small- and medium-sized mammal populations that have taken place there in recent decades.

Interestingly, we found records of dingoes killing or eating 39 native species that are threatened with extinction. This includes the bilby, northern quoll, mountain pygmy possum and bridled nail-tail wallaby. This number is higher than the 28 species recorded in an earlier study of feral cats that used similar methods, probably because the prey size range of dingoes is much wider than that of cats. Nonetheless, subsequent research that drew on museum records, vet reports and other sources has shown that cats actually prey on many more threatened species, including at least 24 bird and 11 reptile species.

It is important to note that these threatened species co-existed with dingoes for thousands of years prior to European arrival in Australia, which means they were able to withstand dingo predation without becoming extinct. However, the small population sizes of threatened species and the impact of other pressures, including predation by introduced foxes and cats, means that these species could be vulnerable to even low rates of predation by dingoes.

Dingoes have been known to exert heavy predation on threatened mammals that are released outside of predator-proof exclosures. This means that predation by dingoes, as well as cats and foxes, should be a key consideration when establishing threatened mammal populations in unfenced landscapes.

Our continent-wide analysis of dingo diets has shown that dingoes have a flexible and generalist diet that includes more than 200 prey species, including pest animals, threatened species and livestock. Dietary studies provide a window into how dingoes interact with other species and respond to environmental change. These kind of studies could even reveal how dingoes might respond to future shifts in prey communities due to climate change, declines of native mammal populations and enhanced control of invasive species.

Tim Doherty is a Research Fellow in the Centre for Integrative Ecology, School of Life and Environmental Sciences, Deakin University.