Tag Archives: predators

Science live chat: protecting the world’s predators

A live chat with Science journal associate editor, Sacha Vignieri.

In this 48-minute Google+ Hangout, we ask: what is it about large predators that makes them so important in ecosystems? How can we ensure their continued survival in a world with increasing human encroachment? And what would a world without predators look like if we fail?

Watch on the Science website

Watch on YouTube

The Conversation: The world’s top predators are in decline, and it’s hurting us too

Without tigers, our ecosystems will suffer. Image by Sascha Kohlmann [CC-BY-SA 2.0] via Flickr

Without tigers, our ecosystems will suffer. Image credit: Sascha Kohlmann via Flickr

Humans have an innate fear of large predators, and with good reason. Nobody wants to be a shark or a lion’s next meal.

But new research in the journal Science shows that our inability to live with these animals is putting their survival in great danger, and doing untold damage to the environment.

Through modifying the habitats of large predators or killing predators more directly, we are greatly compromising the ecosystems that they help to keep in balance — free of charge. In turn this environmental degradation creates many problems that have severe consequences for humans.

We ain’t lion, this predator stuff is a big deal. Image by Derek Keats via Flickr [CC BY 2.0] via Flickr

We ain’t lion, this predator stuff is a big deal. Image credit: Derek Keats via Flickr

Top dogs (and cats) under threat

For the first time, a team of researchers from the United States, Australia, Italy, and Sweden, and led by Professor Bill Ripple at Oregon State University, have analysed the effects of threats such as habitat loss, human persecution and reduced prey on the world’s 31 largest mammalian carnivores.

The species studied include lions, tigers, African wild dogs, leopards, cheetahs, wolves, lynx, otters, bears, hyenas and dingoes. Together they span all continents except Antarctica.

Alarmingly, more than three quarters of the 31 large carnivores are in decline, and 17 species occupy less than half of their historical distributions. The Red Wolf in the southeastern United States is now found in less than 1% of its historical range, and the Ethiopian Wolf in just 2%.

Hotspots of carnivore decline are southeast Asia, southern and East Africa, and the Amazon, where several large carnivores are declining. And in the developed world there are now few places where large carnivores remain.

In Australia, dingoes help keep introduced predators at bay. Image credit: Ars Electronica [CC BY-NC-ND 2.0] via Flickr

In Australia, dingoes help keep introduced predators at bay. Image credit: Ars Electronica via Flickr

Aside from the intrinsic tragedy of losing any species, what should perhaps concern us even more is that we are only just beginning to understand and appreciate just how important large predators are to maintaining healthy ecosystems, and our dependence on the ecosystem services they deliver.

Ripple effect

Seven carnivore species in particular have been shown to have profound effects on the environment and cause what is known as “trophic cascades”. A trophic cascade is a ripple effect, where one species’ influence spreads through multiple levels of a food web.

Species for which this effect is most well-known are African lions, leopards, Eurasian lynx, cougars, gray wolves, sea otters and dingoes.

It’s hard being a VIP (very important predator). Image credit: Mike Baird [CC BY 2.0] via Flickr

It’s hard being a VIP (very important predator). Image credit: Mike Baird via Flickr

In Australia dingoes greatly reduce kangaroo and red fox numbers, which in turn reduces grazing of vegetation and predation of native animals, helping to conserve and protect biodiversity.

In coastal North America, sea otters keep sea urchin numbers in check, which helps maintain kelp forests and benefits other marine species dependent on this habitat. But in this case otters might also offer a defence against climate change, as healthy kelp forests can grow rapidly and store large amounts of carbon.

And in Africa, a decrease in lions and leopards has coincided with a dramatic increase in Olive Baboons, which threaten farm crops and livestock, and spread intestinal worms. Baboons even impact education, as children have to stay home to defend their farms from raids.

Without lions and leopards, there’s no telling what baboons will do. Image credit: Justin Jensen [CC BY 2.0] via Flickr

Without lions and leopards, there’s no telling what baboons will do. Image credit: Justin Jensen via Flickr

Clearly predators have far-reaching ecological, economic and social benefits that are grossly underappreciated. There is no doubt predators pose challenges too, such as wolves attacking livestock. But education and new management practices offer ways forward. For instance, we could use guardian animals to protect livestock from predators.

Together we call on governments to end policies and management practices that are responsible for the ongoing persecution and loss of predators from our planet. Western Australia’s new shark plan is an example of management that fails to account for the science of big predators. Instead we need an international initiative that aims to conserve large predators and promote their coexistence with people.

This article was originally published at The Conversation. Read the original article.

The Conversation

Big Desert update 2

I’ve just returned from a glorious two-week family holiday in sunny north Queensland. How I’ve missed the place, so much cool wildlife everywhere! Among the highlights were spotting a male cassowary with three chicks (my son is currently obsessed with these oversized birds), watching platypus swim from our front veranda on the Atherton Tablelands — if you’re looking for a biologist’s paradise you can’t go wrong here — and taking the kids spotlighting for NQ’s arboreal mammals. We missed out on tree kangaroos, alas, but we did see green ringtail, lemuroid, and Herbert River ringtail possums, coppery brushtail possums and long-nosed bandicoots. And at age five, Rohan seems to be well on his way to a successful career in field ecology, spotting the eye-shine of many possums himself.

But enough on holidays; what I’d like to update everyone on is the first results to roll in from our Big Desert work. As I’ve written previously, this is an incredibly remote and largely unstudied region, so there’s much to be discovered and learned. What have we found so far? Well, I’ll let the video, below, do most of the talking, but what’s most exciting is that we’ve confirmed there is a dog population in the park, and some individuals appear to look very much like dingoes. We always suspected this, but it’s nice to have positive confirmation. Another interesting result is that goats were not recorded on any of the cameras so far, as compared to the Murray Sunset National Park, to the north, where goats are very abundant, but dogs/dingoes are absent. It’s early days, the habitats of Murray Sunset and the Big Desert / Wyperfeld region are somewhat different, and I’m sure we’ll find some goats in the region soon enough, as they’ve been recorded there. But, it does suggest dingoes may be playing a role in keeping goat numbers down, as we know they do from other studies conducted in other parts of Australia .

Some may remember the Victorian Government recently reviewed the evidence for the existence of big cats; the legendary Black Panther. Well, we may just have found it ourselves! (second-last clip in the video). On a serious note though, cats appear to be relatively common, and great variation exists in their morphology (as seen on the videos). Cats are known to be a major factor behind the extinction of many native species, and new research also shows how they have large impacts on wildlife through the spread of toxoplasmosis. We’re keen to understand more about the role of foxes and dingoes in suppressing cats and therefore disease transmission, but more on that later…

No rest for the wicked. I’m off to Belfast next week to attend the 11th International Mammalogical Congress. I’ll be speaking about the dingo barrier fence and co-chairing a symposium on trophic cascades, ecological restoration and conservation of mammals. I’m really looking forward to a week of listening to mammal research from around the world, and perhaps just a wee Guinness or two as well.