Spontaneous tool-use: an observation of a dingo (Canis dingo) using a table to access an out-of-reach food reward

Opportunities to observe non-human animals exhibiting naturalistic 'high-order' behaviour are rare. Examples featuring canids, although often anecdotal and involving captive animals are potentially valuable, as they may provide an opportunity to examine complex problem-solving behaviour not easily observed in free-ranging settings. This paper describes observations of two captive male dingoes (Canis dingo), representing possible examples of high-order behaviour. The first set of observations involved a sub-adult male that spontaneously (i.e., without training) learned to move objects around his enclosure, apparently to multiple ends, such as in an effort to gain the additional height required to attain objects otherwise out of reach, or to attain a better view of his surroundings. The second set of observations involved an adult male that learned to open a gate, possibly in an effort to gain access to a female. These observations add to the small number of anecdotal accounts offering a window into the cognitive abilities of canids, and the observations involving the sub-adult male appear to be the first documented cases of tool-use in a canid.     

The feeding ecology of the dingo

Summary Changes in the diet of dingoes (Canis familiaris dingo) in response to measured fluctuations of prey populations were followed over 7 years. The study began after great rains had broken a long drought. Eruptions of rodents and rabbits followed, but some prey were always either relatively abundant (live cattle) or scarce (red kangaroo, lizards, birds). Cattle carcasses were increasingly available during a subsequent drought. Small and medium-sized prey, rodents (26%), lizards (12%) and rabbits (56%) were preferred, probably because they were easily caught. Only rabbits were caten consistently regardless of density. By contrast, large prey were eaten in relatively large amounts only during drought, with initial emphasis on red kangaroos (15% overall) and then cattle (17%) mostly as carcasses. The diet was functionally related to the respective abundances of all major prey species, but the relationship shifted during drought when predation on low populations was most severe. There was evidence that growth of resurging prey populations were suppressed by predation. Diets of dingoes did not differ significantly with age or sex. An hypothesis of alternation of predation is presented: dingoes feed sequentially on prey of increasing size (rodents, rabbits, red kangaroos, cattle) in response to rainy periods and subsequent droughts, meanwhile always concentrating on the staple prey (rabbits). The fluctuating abundances of small and medium-sized prey determined not only their own relative availabilities but also that of large prey, and hence determined the diet of the dingo at any time. Prey availability (catchability, accessability) appeared to be more important than prey abundance (numbers, biomass), and the dingo's flexible social organisation allowed versatility in hunting strategies and defence of resources. We conclude that dingoes do not always forage most efficiently as optimal foraging models predict because of the constraints imposed by the capricious environment in arid Australis, where prey availability fluctuates greatly and becomes limited and clumped in drought, so that dingoes may be faced with outright starvation. Instead we conclude that dingoes utilise a conservative feeding strategy and adopt any behaviour which provides at least a threshold quantity of energy or nutrient as part of a trade-off with other competing ecological requirements.     

Ecological connectivity or Barrier Fence? Critical choices on the agricultural margins of Western Australia

Western Australia's State Barrier Fence represents a continuation of colonial era attitudes that considered kangaroos, emus and dingoes as ‘vermin’. Recent plans to upgrade and extend the Barrier Fence have shown little regard for ecological impacts or statutory environmental assessment processes.     

Does a top-predator provide an endangered rodent with refuge from an invasive mesopredator?

In arid environments, ecological refuges are often conceptualised as places where animal species can persist through drought owing to the localised persistence of moisture and nutrients. The mesopredator release hypothesis (MRH) predicts that reduced abundance of top-order predators results in an increase in the abundance of smaller predators (mesopredators) and consequently has detrimental impacts on the prey of the smaller predators. Thus according to the MRH, the existence of larger predators may provide prey with refuge from predation. In this study, we investigated how the abundance of an endangered rodent Notomys fuscus is affected by Australia's largest predator, the dingo Canis lupus dingo , introduced mesopredators, introduced herbivores, kangaroos and rainfall. Our surveys showed that N. fuscus was more abundant where dingoes occurred. Generalised linear modelling showed that N. fuscus abundance was associated positively with dingo activity and long-term annual rainfall and negatively with red fox Vulpes vulpes activity. Our results were consistent with the hypothesis that areas with higher rainfall and dingoes provide N. fuscus with refuge from drought and predation by invasive red foxes, respectively. Top-order predators, such as dingoes, could have an important functional role in broad-scale biodiversity conservation programmes by reducing the impacts of mesopredators.     

Efficacy of an ultrasonic device as a deterrent to dingoes (<Emphasis Type="Italic">Canis lupus dingo</Emphasis>): a preliminary investigation

In April 2001, a 9-year-old child was attacked and killed by dingoes on Fraser Island, Australia. The Dingo Management Strategy formulated in response to this incident proposed ultrasonic deterrents as one of a number of non-lethal management techniques requiring further investigation. In this paper, we describe a preliminary examination of an ultrasonic deterrent to dingoes using four captive animals as test subjects. Although replication was minimal, the use of a simple experimental design, in combination with a flexible analytical technique, sufficiently demonstrated that the unit tested produced no measurable effect as a deterrent to test subjects.     

Evaluating the role of the Dingo as a trophic regulator: Additional practical suggestions

Summary   A recent review paper by Glen et   al . in Austral Ecology (2007, Volume 32 , 492–501) canvassed anecdotal and scientific evidence relating to the role of the Dingo as regulator of ecosystem processes in Australian landscapes. Their review forms part of an increasing volume of literature about the ecological roles of top-order or apex predators around the globe. Although recognizing the possible functional significance of the Dingo is a noteworthy subject matter, the management of the species at an ecosystem scale is complicated by a range of practical and theoretical issues. Perhaps the most significant challenge is the degree to which the Dingo is hybridized with the domestic Dog gone wild (Feral Dog). We suggest here that there is a range of research questions that need to be experimentally addressed as a matter of urgency. This includes but is not limited to understanding the ecological significance of Dingo–Dog hybridization. Such research should precede other research initiatives suggested by Glen et   al. such as reintroducing individuals of the pure Dingo back into landscapes. This is particularly the case for south-eastern mainland Australia where the incidence of Dingo–Dog hybridization is high and the ecological consequences of this poorly understood. Finally, new terminology may be needed relating to Dingo and/or Wild Dog management that more clearly reflects both the genetic status of the species as well as its ecological function.