Rhino Poaching Crisis conference and the Woolly Rhino

Did you know the collective noun for a group of rhinos is a crash (TheAlmightyGuru-Animal Groups)? Rhinos are recognisable by their massive bodies, stumpy legs and one or two dermal horns, made out of keratin (the same stuff as your hair and nails) (WWF rhino).  

There are five extant species of rhino: 

1. The White Rhino (Ceratotherium simum) which has two sub species: the Southern White Rhino and the Northern White Rhino

2. The Black Rhino (Diceros bicornis) (split into four sub species) 

3. Greater One Horned  (Rhinoceros unicornis)

4. The Javan Rhinoceros (Rhinoceros sondaicus) 

5. The Sumatran Rhinoceros (Dicerorhinus sumatrensis) (WWF rhino). 

From wikicommons

All species of rhinoceros are under threat of extinction (for example, see IUCN Javan Rhino), through habitat loss and poaching for sale on a highly lucrative black market. Their horns are valued for use in traditional medicine in parts of Asia, especially in Vietnam.


There are moves to change this attitude, see this video with the Duke of Cambridge, David Beckham and Yao Ming. A sad update to the info in this video - there are now only 4 Northern White rhino left, not 7 (WWF rhino).

At the ZSL Rhino Poaching Crisis conference, multiple angles were discussed as to what can be done to save these modern megafauna. One speaker took the attitude that low tech approaches with better paid and provisioned rangers was the way forward (some work in appalling conditions - how can they be expected to risk their lives each day when they aren't even provided with beds at night or basic washing facilities? Unhappy rangers is surely a recipe for disaster). 

She also cautioned that the small pockets of rhinos would be lost, and it was vital to concentrate on the stronghold populations. 

Others talked about the veterinary interventions that in a very small number of cases (i.e., 1 or 2) had managed to save a rhino that was found just after it had been attacked. You can see the video of an individual that's just been found after an attack here  - however, please be warned it is graphic, horrifying and deeply saddening. It's linked rather than included in this post so you can choose whether to see or not. 

More economically-minded approaches were also discussed by Jonathan Baillie (Head of ZSL conservation operations), centering on an impact bond that is only paid to the groups doing the conserving when they meet result based targets. And while I have to admit most of this section went slightly over my head, it seemed like a very people-focused way of funding rhino conservation, which is probably a more efficient way of getting a wider audience on board. 

From thehulkangre.deviantart

While many species of rhino today are critically endangered, the Late Pleistocene also saw the extinction of the Woolly Rhino (Coelodonta antiquitatis) from Europe. In an analysis by (Barnosky et al, 2004), the 9 genera of megafauna that went extinct in Europe at this time can be mostly attributed to climate change. The Woolly Rhino was 3 - 3.8m long, and somewhere around 2,700-3,200kg (Twilight Beasts). Growing to 2m tall, the Woolly Rhino was comparable to the extant White Rhino. It had thick fur and the characteristic stocky short legs seen in rhinos today (Twilight Beasts). It has probably been depicted in cave paintings in Europe, although identification of the Woolly Rhino from these images is debatable due to artistic license and varying skill/ age of the painter (Bednarik, 2008). They are also known from specimens mummified in Siberia (Twilight Beasts). They evolved around 3.6 million years ago in Tibet and subsequently expanded across Siberia and Europe. See the Twilight Beasts post for more about their habitats are distribution. 

The rhino poaching crisis is escalating, and we risk losing the species we have today if the demand for their horn doesn't decrease. Trade in rhino horn is now a major criminal activity, with organised syndicates getting rich on the destruction. In you're interested, see a great infographic by WWF here.

The criminals will be the ones who ultimately benefit from the poaching, while the rest of us, including the consumers of this product, lose out with the disappearance of this charismatic, vital piece of wildlife and no actual medical benefit. For something a bit more fun, see this awesome rhino conservation + martial arts video by Jackie Chan, actor turned conservation advocate.  

Trophic cascades in the Cascade Mountains: top-down forcing and wolf reintroduction

Pleistocene North America was lorded over by megafauna such as the dire wolf, American lion and sabertooth cats, along with the more familiar grey wolf and cougar. These predators filled important, apex, roles in their ecosystems.

Top-down versus bottom-up control of ecosystems is an ongoing debate in ecology, although there is considerable empirical evidence for top-down control (Ripple and Valkenburgh, 2010). Ripple and Valkenburgh (2010) argue that this was the case in Pleistocene North America, operating in a trophic cascade system. The predators have effects that cascade to lower trophic levels and eventually effect primary producers.

Previously, it was put forward by Janzen (1983) that humans had help from these predators in causing extinctions. Ripple and Valkenburgh (2010) argue for the opposite, that predators, operating within a cascading top-down process, had help from humans.

“The top-down hypothesis is based on the premise that the arrival of the first humans as hunters and scavengers in the New World at the end of the Pleistocene triggered a sequential collapse of large herbivores and their predators.”

Ripple and Valkenburgh, 2010

Unlike other mammalian carnivore systems, in which interspecific competition (competition between species) is known to affect species densities, humans were omnivorous and probably less subject to 'intraguild predation' (being eaten by other predators), allowing their numbers to increase independently of large-carnivore densities (Ripple and Valkenburgh, 2010).

The trophic cascade with top-down control theory has been pointed to as a benefit of grey wolf reintroduction into areas such as the (aptly named) Cascade Mountains in the USA, Scottish Highlands and mountainous areas of Western Europe. The successful reintroduction of wolves to Yellowstone National Park, USA, has restored diversity, especially with regards to the primary producers which were previously overgrazed by high numbers of herbivores, particularly elk (Cervus elaphus) (Ripple and Beschta, 2012).

There are two main ways in which wolves (and predators in general) influence ecosystems through their effects on herbivores:

(1) Lethal (density-mediated) effects:

by killing herbivores and, therefore, reducing grazing pressure.

(2) Nonlethal (behaviourally-mediated) effects:

by altering foraging patterns and habitat use of herbivores under risk of predation (Ripple and Beschta, 2007). Also called landscapes of fear, (for example see  Laundré et al. (2010)) herbivores in fear of being eaten avoid certain areas where they are more likely to be eaten, affecting ecosystem structure, composition and function.

From Ripple and Beschta (2012):
'Comparison photographs taken in 1997, 2001, and 2010 near the confluence of Soda Butte Creek with the Lamar River illustrating the stature of willow plants during suppression (A) from long-term browsing and their release (B and C) following wolf reintroduction in the winters of 1995–1996. As of 2010, both willow height and canopy cover increased compared to the earlier dates.'

A long term study by Callan et al. (2013) of recolonizing wolves in Wisconsin, USA, found that forb and shrub species richness at local scales was significantly higher in high wolf areas. This is consistent with the predicted trophic effects on understory plant communities triggered by a keystone predator, recovering from regional extinction as the grey wolf currently is (Callan et al., 2013).  

Prehistoric policy needs updating: Modern megafauna extermination

Okay, so I was wrong about the rhino conference. Turns out I have as good a grasp on time as most other students, so I will be saving that post until next week (when the conference actually is). Slightly sidetracking from Pleistocene extinctions, I thought I should highlight the plight of some modern megafauna… 

In a press release last month, the Centre for Biological Diversity, a U.S. nonprofit charity, revealed the recipient of their national Rubber Dodo award. Proudly continuing the traditions of their forebearers, the U.S. Department of Agriculture’s Wildlife Services has been awarded this year’s Annual Rubber Dodo award, given to those who have done the most to drive species extinct. The program killed more than 2 million native animals in 2013 (up 30% on 2012). This amounts to a horrifying tally of 320 grey wolves, 75,000 coyotes, 419 black bears plus many other animals (Centre for Biological Diversity).

Why has this government department decided to rediscover its roots and ramp up its megafauna killing campaign? National politics and individual gain, obviously. Most of Wildlife Services’ killing is done on behalf of the livestock and agriculture industries (Centre for Biological Diversity).

The methods include aerial gunning, traps and exploding cyanide caps (Centre for Biological Diversity). Is it so difficult to imagine Pleistocene North American settlers foreshadowing this megafauna onslaught with ancient traps, snares, spears, atlatls, bone knives and hand axes? Of course that is just speculation, but it is a sobering thought.

8th Rubber Dodo award for killing megafauna and other wildlife
From Centre for Biological Diversity

“No other government program does more every day to annihilate America’s wildlife than Wildlife Services,” said Kierán Suckling, the Center’s executive director. “This rogue program does much of its dirty work far from the public’s view, so millions of animals disappear from our landscapes every year with little accountability.”

From personal experience, many people living in North America often want to preserve their wildlife, and a series of petitions by locals in Newark, New Jersey saw the halt of a planned bear cull (at least, this was the case last time I visited). It’s baffling and saddening then that the American government of Wildlife Services in particular "...seems to delight in the endless slaughter of coyotes, wolves, bears, beavers and countless birds,” Suckling said. “It’s a shameful legacy that should have no place in American government in the 21st century.”

This of course is the official account that says nothing about the “shoot, shovel and shut up” attitude to wolves seemingly prevalent in the gun wielding denizens of Washington State, on the front line of reestablishing wolf populations (and no doubt other areas). While illegal, the locals interviewed in this programme were not shy about their intentions toward wolves – see Land of the Lost Wolves Episode 1:  available for 8 more days! 

It's possible that there was some element of dramatisation in the selection of interviewees with more extreme (okay, incredibly extreme) views. I hope this is the case and that it's not a symptom of wider spread intolerance towards these awe-inspiring animals.

In fact, the grey wolf is making a tenuous comeback in the Washington region of the Cascade Mountain range. The Lookout Pack, (see the documentary above and find out more here) was the first wolf pack seen in the Cascades in more than 70 years. Subsequently, they were slaughtered illegally by local poachers, seemingly because the wolves competed with them for game. The Cascades are in need of an apex predator to naturally restore balance to its ecosystem, as seen after wolves returned to Yellowstone National Park (Manning et al., 2009). There is, however, a potential conflicting interest of wolves and cougars. The cougars have become the dominant predator of the local prey species, and as it is an endangered species itself, the effect of wolf introduction on cougar populations will have to be carefully monitored...

Grey Wolf (left) in comaprison with it's Dire Wolf cousin (right)
From DireWolfProject 

I have an awful lot to say about wolves so to do them justice, I’ll talk about why wolves, both extant and extinct, are such key components of their ecosystems in the next post, and the consequences of their absence, both in the Pleistocene and relatively recently. 

Ecological Hangover

Large herbivores have a large impact on the vegetation they rely on. They affect the structure, composition and dynamics of plant communities. 50,000 years ago, many more herbivore giants existed, and there is considerable evidence to suggest that their absence has affected the vegetation communities they left behind. 

Johnson (2009) argues that extinct megafauna once kept the landscape more open, creating gaps in the vegetation. This creates a mosaic landscape: a mix of open, undisturbed and somewhere-in-the-middle plant communities. A greater variety of habitats equals a greater variety of species. More sunlight in cleared areas allows different species of plant to grow, and a mosaic landscape where plant communities are moving through various successional stages would at any one time would increase the diversity of this landscape. They also enabled accelerated nutrient cycling via urine and faces and altered fire regimes by reducing accumulation of dry plant matter (Johnson, 2009). 

So when these giants went extinct, and the habitats became more uniform for lack of megafauna-made gaps, plant community diversity may have decreased along with them. The mosaic would have become more like a wheat field. 

Plant communities that once defended against browsing mega-herbivores with spines and toxins are now inedible by modern stand-ins. The plant's seed dispersal mechanisms too, designed for the missing megafauna, are now obsolete. These plants may be in decline for this reason, meaning that plant communities may be in a process of relaxing from the selective pressures the megafauna imposed. Contemporary plant communities may therefore be far from stable and established, but in a transitional period (Johnson, 2009).    

On its last legs? The Javan Rhinoceros
From: It's nature

There is side-note to this debate: ecological extinction. The Javan Rhino suffers from this condition, and it's likely that towards the end of their time on Earth mammoths, mastodons and other giant herbivores suffered the same fate. Ecological extinction occurs when the populations of a species are so low in number that they no longer fulfill their ecological role, such as tree-felling, seed dispersal etc. 

Speaking of Rhinos, it's the ZSL "Responding to the Rhino Poaching Crisis" meeting next week, so I'll be posting about these endangered megafauna soon! 

Hindgut haven turned sour: Habitat change as the driver of mammoth and horse declines in North America prior to human settlement?

Some of the arguments for climate mediated megafauna extinctions I find most interesting are made by Dale Guthrie, a palaeobiologist from the University of Alaska.

Guthrie believes megafauna in Alaska and the Yukon were hard hit by climate change long before people arrived. This view stems from a better understanding of ecosystem communities. In the past, ecologists believed that Pleistocene habitats and communities were the same we see today, only in different locations. Guthrie was one of the first to suggest that this may not be the case (Levy, 2011).

Pleistocene habitats were not simply modern ones in different locations: communities then were very different, with assemblages of organisms no longer found anywhere near each other.
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Pleistocene Alaska was cold and dry; known as "mammoth steppe" (Levy, 2011). Few trees grew and grassland dominated. This habitat faded away at the end of the Ice Age, along with many of its inhabitants, including the woolly mammoth and rhino.

Bison and moose, however, prevailed (Guthrie, 2006). Why was that? Bison and moose are ruminants who ferment their food in a large forestomach called the rumen. Plants build their cell walls from cellulose; a substance only bacteria have evolved to digest. The rumen harbours cellulose munching bacteria which breaks down the plant matter before digestion. Plants also produce toxins designed to put off browsers. Fermentation occurring in the rumen enables these herbivores to cope with these toxins (Levy, 2011).  

However all this processing means that digestion is slow. Horses and elephants have another strategy: they also ferment their food, not in a rumen but in a pouch called a cecum, behind the small intestine. The cecum is further along the digestive tract and can therefore absorb proteins that would otherwise be broken down by microbes in a ruminant. So horses can make do on tough, old grasses - a diet which wouldn't support a ruminant (Levy, 2011).

The cold, arid plains of Ice Age Alaska had short growing seasons and lots of grass: perfect conditions for hindgut (cecum) fermenters like the horse and mammoth. But as the climate warmed, trees and shrubs colonised the landscape, beginning at the banks of the new meltwater streams (Levy, 2011). This vegetation was armed with toxins only a ruminant could digest. Guthrie believes these habitat shifts, occurring 14-15,000 years ago, drove the decline of horse and mammoth, long before the Clovis people arrived (Guthrie, 2006).

This idea is corroborated by the fact that the region's most recent horse fossils date from this window of time. During this same period, bison, elk and moose (ruminants) populations exploded and expanded north. Mammoths became less common at this time before finally vanishing 13,000 years ago (Levy, 2011). Guthrie sees the deterioration of the hindgut haven that was Ice Age Alaska as the driving force of megafauna decline, with humans possibly later dealing a final blow. From this he suggests that the Blitzkrieg, keystone removal and palaeodisease models for megafauna extinctions can be rejected, at least for the Alaska-Yukon area (Guthrie, 2006).