Game bird madness

4 11 2015

Gamecart_largeI just returned to Paris after a brief visit to the University of Aberdeen over the weekend. My hosts, Xavier Lambin and Beth Scott, were not only marvellously welcoming, I also learned a lot about the travesty that is game bird management in the United Kingdom, and especially in Scotland.

As you might already know, the Great Britons are a little cuckoo for birds — I’d even wager that the country produces more twitchers than any other country on Earth. The plus side is that there are few national taxa better censused and studied that British birds, because so many non-scientists get into the spirit of data collection. Hell, I’ve even had a play with some of their datasets.

The other side of this bird madness is not so good — I’m talking about the massive biomass of game birds reared, released and shot every year in the United Kingdom. It’s not the hunting per se with which I take issue, it’s the insane manipulation of an entire ecosystem for the benefit of a few species. Read the rest of this entry »

What’s in a name? The dingo’s sorry saga

30 01 2015

bad dingoThe more I delve into the science of predator management, the more I realise that the science itself takes a distant back seat to the politics. It would be naïve to think that the management of dingoes in Australia is any more politically charged than elsewhere, but once you start scratching beneath the surface, you quickly realise that there’s something rotten in Dubbo.

My latest contribution to this saga is a co-authored paper led by Dale Nimmo of Deakin University (along with Simon Watson of La Trobe and Dave Forsyth of Arthur Rylah) that came out just the other day. It was a response to a rather dismissive paper by Matt Hayward and Nicky Marlow claiming that all the accumulated evidence demonstrating that dingoes benefit native biodiversity was somehow incorrect.

Their two arguments were that: (1) dingoes don’t eradicate the main culprits of biodiversity decline in Australia (cats & foxes), so they cannot benefit native species; (2) proxy indices of relative dingo abundance are flawed and not related to actual abundance, so all the previous experiments and surveys are wrong.

Some strong accusations, for sure. Unfortunately, they hold no water at all. Read the rest of this entry »

Help Hawaii’s hyper-threatened birds

6 01 2015
Puaiohi or small Kaua'i thrush. Photo by Lucas Behnke

Puaiohi or small Kaua’i thrush. Photo by Lucas Behnke

You wouldn’t want to be a bird in Hawaii. There are more avian species threatened with extinction there than anywhere else in the USA. After humans arrived, some 70+ species have become extinct, and 31 are listed as threatened with extinction. In addition, 43% of 157 species are not native; among land birds, 69% are introduced species.

My friend, Cali Crampton asked me to promote their new crowdfunding project to reduce the threat of feral rats on Hawaiian birds. Please help if you can.

The Kaua‘i Forest Bird Recovery Project, a collaborative project of the Hawaii Department of Land and Natural Resources, Division of Forestry and Wildlife, the University of Hawaii Pacific Cooperative Studies Unit, and Garden Island Research and Development, has announced the launch of a crowdfunding and outreach campaign to generate support for protecting the native birds of Kaua’i by controlling rats with humane, self-resetting rat traps.

The campaign, named “Birds, not Rats!” runs through to 31 January 2015, with goals of increasing awareness of the threats that rats pose to birds and native ecosystems, and raising at least $10,000 for rat control through many small, individual donations.

Hawai’i is at the epicentre of the current global extinction crisis. Of the original 130+ native Hawaiian bird species, many have been lost forever, and only 11 are not yet endangered. Today, Kaua’i is home to eight native forest bird species, three of which are federally listed as endangered: the puaiohi or small Kaua’i thrush, the akeke’e or Kaua’i akepa, and the akikiki or Kaua’i creeper. Populations of these birds have plummeted as much as 90% in the last five years; the akikiki and the puaiohi now number fewer than 500 individuals, and the akeke’e numbers fewer than 1000 individuals. The Kaua’i Forest Bird Recovery Project’s goal is to reverse these declines. Read the rest of this entry »

Using ecological theory to make more money

1 12 2014

huge.9.46974Let’s face it: Australia doesn’t have the best international reputation for good ecological management. We’ve been particularly loathsome in our protection of forests, we have an appalling record of mammal extinctions, we’re degenerate water wasters and carbon emitters, our country is overrun with feral animals and weeds, and we have a long-term love affair with archaic, deadly, cruel, counter-productive and xenophobic predator management. To top it all off, we have a government hell-bent on screwing our already screwed environment even more.

Still, we soldier on and try to fix the damages already done or convince people that archaic policies should be scrapped and redrawn. One such policy that I’ve written about extensively is the idiocy and cruelty of the dingo fence.

The ecological evidence that dingoes are good for Australian wildlife and that they pose less threat to livestock than purported by some evidence-less graziers is becoming too big to ignore any longer. Poisoning and fencing are not only counter-productive, they are cruel, ineffective and costly.

So just when ecologists thought that dingoes couldn’t get any cooler, out comes our latest paper demonstrating that letting dingoes do their thing results in a net profit for cattle graziers.

Come again? Read the rest of this entry »

More species = more resilience

8 01 2014

reef fishWhile still ostensibly ‘on leave’ (side note: Does any scientist really ever take a proper holiday? Perhaps a subject for a future blog post), I cannot resist the temptation to blog about our lab’s latest paper that just came online today. In particular, I am particularly proud of Dr Camille Mellin, lead author of the study and all-round kick-arse quantitative ecologist, who has outdone herself on this one.

Today’s subject is one I’ve touched on before, but to my knowledge, the relationship between ‘diversity’ (simply put, ‘more species’) and ecosystem resilience (i.e., resisting extinction) has never been demonstrated so elegantly. Not only is the study elegant (admission: I am a co-author and therefore my opinion is likely to be biased toward the positive), it demonstrates the biodiversity-stability hypothesis in a natural setting (not experimental) over a range of thousands of kilometres. Finally, there’s an interesting little twist at the end demonstrating yet again that ecology is more complex than rocket science.

Despite a legacy of debate, the so-called diversity-stability hypothesis is now a widely used rule of thumb, and its even implicit in most conservation planning tools (i.e., set aside areas with more species because we assume more is better). Why should ‘more’ be ‘better’? Well, when a lot of species are interacting and competing in an ecosystem, the ‘average’ interactions that any one species experiences are likely to be weaker than in a simpler, less diverse system. When there are a lot of different niches occupied by different species, we also expect different responses to environmental fluctuations among the community, meaning that some species inherently do better than others depending on the specific disturbance. Species-rich systems also tend to have more of what we call ‘functional redundancy‘, meaning that if one species providing an essential ecosystem function (e.g., like predation) goes extinct, there’s another, similar species ready to take its place. Read the rest of this entry »

Don’t blame it on the dingo

21 08 2013

dingo angelOur postdoc, Tom Prowse, has just had one of the slickest set of reviews I’ve ever seen, followed by a quick acceptance of what I think is a pretty sexy paper. Earlier this year his paper in Journal of Animal Ecology showed that thylacine (the badly named ‘Tasmanian tiger‘) was most likely not the victim of some unobserved mystery disease, but instead succumbed to what many large predators have/will: human beings. His latest effort now online in Ecology shows that the thylacine and devil extinctions on the Australian mainland were similarly the result of humans and not the scapegoat dingo. But I’ll let him explain:

‘Regime shifts’ can occur in ecosystems when sometimes even a single component is added or changed. Such additions, of say a new predator, or changes such as a rise in temperature, can fundamentally alter core ecosystem functions and processes, causing the ecosystem to switch to some alternative stable state.

Some of the most striking examples of ecological regime shifts are the mass extinctions of large mammals (‘megafauna’) during human prehistory. In Australia, human arrival and subsequent hunting pressure is implicated in the rapid extinction of about 50 mammal species by around 45 thousand years ago. The ensuing alternative stable state was comprised of a reduced diversity of predators, dominated by humans and two native marsupial predators ‑ the thylacine (also known as the marsupial ‘tiger’ or ‘wolf’) and the devil (which is now restricted to Tasmania and threatened by a debilitating, infectious cancer).

Both thylacines and devils lasted on mainland Australia for over 40 thousand years following the arrival of humans. However, a second regime shift resulted in the extinction of both these predators by about 3 thousand years ago, which was coincidentally just after dingoes were introduced to Australia. Dingoes are descended from early domestic dogs and were introduced to northern Australia from Asia by ancient traders approximately 4 thousand years ago. Today, they are Australia’s only top predator remaining, other than invasive European foxes and feral cats. Since the earliest days of European settlement, dingoes have been persecuted because they prey on livestock. During the 1880s, 5614 km of ‘dingo fence’ was constructed to protect south-east Australia’s grazing rangelands from dingo incursions. The fence is maintained to this day, and dingoes are poisoned and shot both inside and outside this barrier, despite mounting evidence that these predators play a key role in maintaining native ecosystems, largely by suppressing invasive predators.

Perhaps because the public perception of dingoes as ‘sheep-killers’ is so firmly entrenched, it has been commonly assumed that dingoes killed off the thylacines and devils on mainland Australia. People who support this view also point out that thylacines and devils persisted on the island of Tasmania, which was never colonised by dingoes (although thylacines went extinct there too in the early 1900s). To date, most discussion of the mainland thylacine and devil extinctions has focused on the possibility that dingoes disrupted the system by ‘exploitation competition’ (eating the same prey), ‘interference competition’ (wasting the native predators’ precious munching time), as well as ‘direct predation’ (dingoes actually eating devils and thylacines). Read the rest of this entry »

Learning from danger

13 05 2013
Guanaco fleeing
Study vehicle, a group of vicuñas and a guanaco in San Guillermo National Park (San Juan, Argentina) [courtesy of Marco Escudero]. Guanacos and vicuñas are native to South America, and are the ancestors of domesticated llamas and alpacas – which are exploited for their meat, milk and wool. Both species form monotypic genera. They have discontinuous distributions in Argentina, Bolivia, Chile and Peru, with introduced populations in Paraguay (guanaco) and Ecuador (vicuña). Population estimates are > 500,000 (guanaco) and > 300,000 (vicuña), the latter restricted to high-altitude ecosystems. They are ‘Least Concern’ for the IUCN but, given their low population growth rates (fertility = 1 offspring/female/yr), guanacos and vicuñas are targeted by conservation programs in all their native countries.

Many of us might have stumbled twice on the same stone, yet learnt to be wary of future situations of similar risk. Likewise, wild animals can be predisposed to flee when faced with already known predators (or threats in general). The type and magnitude of their evasive response depends on predator distance, speed and body size (1). Regardless, prey need to assess predation risk in a matter of seconds (or even shorter than that), i.e., balancing the benefits and costs of fleeing.

The benefits all boil down to survival, but the costs might include moving away from offspring, loss of access to fresh and abundant food, or spending precious metabolic energy (2). The methods ecologists use to study animal flight behaviour in the wild are rife with nuisances (3), yet they represent a tool for quantifying wildlife stress resulting from a variety of human activities.

Equipped with our modern technological kit (weapons, vehicles, GPS, etc.), humans behave like genuine predators and can trigger the range of flight behaviours displayed by their potential prey. In that context, Emiliano Donadio and Steve Burskirk (4) studied flight behaviour of guanacos (Lama guanicoe) and vicuñas (Vicugna vicugna) in the Argentinean open plains (‘llanos’). They monitored 2 protected areas under weak surveillance and subject to illegal hunting: the Laguna Brava Provincial Reserve and the San Guillermo Biosphere Reserve (treatment = H); and one area free of hunting and only exposed to guided visits with strict entry/exit times: the San Guillermo National Park (treatment = NH). The ecologists did 3 transects per study area. When they encountered a group of camelids, they classified three types of flight behaviour (alert without fleeing, walking away, galloping away), and measured flight time (between vehicle detection and initiation of flight behaviour) and flight distance (between the vehicle and the individuals when initiating flight behaviour). Read the rest of this entry »


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