Authors: Thomas M Newsome, Aaron C Greenville, Mike Letnic, Euan G Ritchie and Christopher R Dickman
Published in: Food Webs (early view)
In their paper “Trophic cascades and dingoes in Australia: does the Yellowstone wolf-elk- willow model apply?” Morgan et al. (2016) argue that the case for dingo reintroduction in Australia, based on trophic cascade theory, is “weak”. They conclude that, “because of climate instability, the strong top-down trophic responses reported from the Yellowstone National Park case study are unlikely to apply in arid and semi-arid south-eastern Australia and are speculative at best”.
We agree that dingoes (Canis dingo) are likely to exert different effects on ecological communities in Australia as compared to grey wolves (Canis lupus) in North America. A comparison of body sizes and dietary preferences between these canid species alludes to their functional ecological differences. Differences in the biological communities and climate between Yellowstone National Park and Australia also prevent direct comparisons of trophic cascade-processes between the two regions. These facts should not, however, preclude examination of the efficacy and consequences of dingo reintroductions in Australia.
We contend that Morgan et al. (2016):
- misunderstand the circumstances that make trophic cascades important to consider in Australia,
- do not acknowledge key reasons why dingo reintroduction has been proposed,
- haven’t recognised the different pathways by which dingoes could influence ecosystems via trophic cascades, and
- do not fully acknowledge literature and theory relevant to understanding the interplay of bottom-up and top-down processes in Australia.
Our reply is intended to assist managers and decision makers when deciding whether or not to reintroduce dingoes into Australian ecosystems.