A Real-Life “Big, Bad Wolf”

22 06 2007

Mexican Wolf
A Mexican Wolf (Canis lupus baileyi), the most genetically-distinct subspecies of Grey Wolf (Canis lupus) at the National Zoo in Washington, D.C.

One of the most famous stories in the history of paleontology is of how William Buckland, the noted 19th century geologist, determined that a pack of hyenas once inhabited Kirkdale Cave in Yorkshire, England by observing the markings living hyenas made on bones at the zoo. While the science of taphonomy would not fully emerge until the next century, it became clear that fossil bones could tell us about scavengers and predators as well as the preserved prey. It’s no surprise that hyenas especially would “make their mark” on so many bones, the extant Spotted Hyena (Crocuta crocuta being well known for its jaw strength and ability to crack bone (which provides mothers with extra calcium for milk, and these hyenas nurse their young for a relatively long period of time as pups are not weaned until they are a year older or more). Now, a new study of various wolf remains reveals a Pleistocene predator distinct from the Grey Wolves in Yellowstone or anywhere else in North America. The abstract of the new Current Biology paper “Megafaunal Extinctions and the Disappearance of a Specialized Wolf Ecomorph” by Leonard, et al. states;

The gray wolf (Canis lupus) is one of the few large predators to survive the Late Pleistocene megafaunal extinctions. Nevertheless, wolves disappeared from northern North America in the Late Pleistocene, suggesting they were affected by factors that eliminated other species. Using skeletal material collected from Pleistocene permafrost deposits of eastern Beringia, we present a comprehensive analysis of an extinct vertebrate by exploring genetic (mtDNA), morphologic, and isotopic (d 13C, d 15N) data to reveal the evolutionary relationships, as well as diet and feeding behavior, of ancient wolves. Remarkably, the Late Pleistocene wolves are genetically unique and morphologically distinct. None of the 16 mtDNA haplotypes recovered from a sample of 20 Pleistocene eastern-Beringian wolves was shared with any modern wolf, and instead they appear most closely related to Late Pleistocene wolves of Eurasia. Moreover, skull
shape, tooth wear, and isotopic data suggest that eastern-Beringian wolves were specialized hunters and scavengers of extinct megafauna. Thus, a previously unrecognized, uniquely adapted, and genetically distinct wolf ecomorph suffered extinction in the Late Pleistocene, along with other megafauna. Consequently, the survival of the species in North America depended on the presence of more generalized forms elsewhere.

Unfortunately there are no photographs or illustrations of the skulls studied to reach these conclusions, but as with other mammals the condition and placement of the teeth is absolutely key. This extinct group of wolves had a much higher amount of tooth wear and fracture than modern wolves (or even other groups of extinct carnivores like Dire Wolves and Saber-Toothed Cats), as well as having a skull shape that would have granted them greater bite forces. These wolves also seem to have had a relatively deep (I assume we’re talking from top to bottom) jaws, characteristic of bone-crackers like hyenas and living wolves that take down large prey. This wolf was not particularly larger than wolves currently living in Alaska or fossil wolves from the La Brea Tar Pits, but the construction of its skull and tooth wear make it apparent that it certainly was an effective predator and scavenger.

The evolution of these wolves is also covered in the paper, and it seems that the bone-crushing wolves and extant wolves share a common ancestor that came from Europe or elsewhere in the Old World, the genetic tests showing that the “new” wolves were not the ancestors of modern Grey Wolves. Instead, it seems that the more robust wolves to the north were middle-weights as far as carnivore ecology (Dire Wolves being larger, Coyotes being smaller), and when Dire Wolves became extinct the Grey Wolves began to become adapted to taking larger prey and cracking bones. The authors of the paper suggest that being an overspecialized “hypercarnivore” may have ultimately done the wolf in, its more generalized southern cousins better able to adapt to changing conditions at the end of the Pleistocene. I’m not particularly sure about this argument, but I’m not expert enough to prove it incorrect either.

In any event, I hope more researchers dive into the mountains of fossil remains languishing in museums all over the world; I almost have to wonder if there are just as many species waiting in dusty cabinets as there are still waiting in the rock.





Learning to fear predators, OR Ecologists have more fun

22 06 2007

One of the most well-known (albeit misunderstood) tales of extinction is that of the dodo; while the birds were capable of defending themselves if necessary, they generally did not fear sailors that came onto the islands. The dodos were beset by an invasion of men, pigs, rats, and other creatures they had no experience with, and the ecological degradation as well as their inability to consider man a predator led to the ultimate demise of the species. I can only wonder if the dodo would have persisted if their pressures upon it were not so acute; would it have learned to be wary of humans? That is a question that cannot be answered, but a new study by Dr. Joel Berger of the WCS has uncovered some surprising insights into predator-prey interactions, revealed in the new paper “Carnivore Repatriation and Holarctic Prey: Narrowing the Deficit in Ecological Effectiveness” in the journal Conservation Biology (and I just canceled my subscription due to lack of service too. Damn!)

Keystone predators have been nearly eradicated in their natural ranges all over the world, wolves, tigers, and brown bears being some of the most notable carnivores. In their absence, new generations of ungulates like moose and deer have never learned what a wolf howl or tiger growl sounds like, and so they have little response to the sounds and smells of predators. Using recordings (and perhaps even urine-soaked snowballs), Berger has found that prey animals typically do not react quickly to various stimulus that would indicate a predator they have no experience with. There have been efforts to reintroduce predators, however, and wolves were successfully brought back to Yellowstone in 1995. When Berger found was that the Bison in Yellowstone had learned to recognize wolf howls, responding even more strongly than bison in other areas that have had constant contact with wolves over many generations, showing that prey animals can indeed learn to fear predators again.

Also of importance is the area in which the prey is located when confronted with signs of a predator; snow depth and distance from cover may make a difference as to how prey reacts. Unfortunately I don’t have access to the whole article, but it sounds absolutely amazing. I can only imagine what it must have been like to undertake such a study; visiting locations all over the world in order to quiet fears that predators will decimate prey populations if introduced. So, I can has grant to continue research?

Paper abstract;

The continuing global decline of large carnivores has catalyzed great interest in reintroduction to restore populations and to reestablish ecologically functional relationships. I used variation in the distribution of four Holarctic prey species and their behavior as proxies to investigate the pace and intensity by which responses are lost or reinvigorated by carnivore repatriation. By simulating the presence of wolves (Canis lupus), tigers (Panthera tigris), and brown bears (Ursus arctos) at 19 transcontinental sites, I assayed three metrics of prey performance in areas with no large terrestrial carnivores (the polar islands of Greenland and Svalbard), extant native carnivores (Eastern Siberian Shield, boreal Canada, and Alaska); and repatriated carnivores (the Yellowstone region and Rocky Mountains). The loss and reestablishment of large carnivores changed the ecological effectiveness of systems by (1) dampening immediate group benefits, diminishing awareness, and diminishing flight reaction in caribou (Rangifer tarandus) where predation was eliminated and (2) reinstituting sensitivity to carnivores by elk (Cervus elaphus) and moose (Alces alces) in the Yellowstone region to levels observed in Asian elk when sympatric with Siberian tigers and wolves or in Alaskan moose sympatric with wolves. Behavioral compensation to reintroduced carnivores occurred within a single generation, but only the vigilance reaction of bison (Bison bison) in Yellowstone exceeded that of their wolf-exposed conspecifics from boreal Canada. Beyond these overt responses by prey, snow depth and distance to suitably vegetated habitat was related to heightened vigilance in moose and elk, respectively, but only at sites with carnivores. These findings are insufficient to determine whether similar patterns might apply to other species or in areas with alien predators, and they suggest that the presumed excessive vulnerability of naïve prey to repatriated carnivores may be ill-founded. Although behavior offers a proxy to evaluate ecological effectiveness, a continuing challenge will be to understand how naïve prey respond to novel or introduced predators.





Is there a civet in your perfume?

3 06 2007

One of the most curious aspects of dating and relationships in technologically advanced countries is the need for people to cover up their natural scent with lots of different products. For my own part, my current shampoo, conditioner, body soap, deodorant, and cologne are all different, and I douse myself with foreign scents to make sure that I do not offend the olfactory sensibilities of others. But where do such scents come from? There are plenty of synthetic chemicals that mimic naturally (or unnaturally) occurring scents, but, interestingly enough, some fragrances still require animal sources. As Terry Pratchett wrote in The Unadulterated Cat (which ironically sits next to a basket of the products I mentioned above in the bathroom);

Civet

An 1894 Richard Lydekker painting of an African Civet

The civet cat has been a nervous animal ever since it discovered that you can, er, derive civetone* from it and use it in scent. Exactly how this is done I don’t know and do not wish to research. It’s probably dreadful. Oh, all right, I’ll have a look.

It is.+

*A 17-member ring-ketone, according to my dictionary, as opposed to the mere 15-membered muscone from the musk deer. Does the civet feel any better for knowing this? Probably not.

+Who invents these scents, anyway? There’s a guy walking along the beach, hey, here’s some whale vomit, I bet we can make scent out of this. Exactly how likely do you think this is?

Indeed, the civet’s (specifically the African Civet, Civetticus civetta) scent is also useful to those wishing to track big cats, a researcher in a recent issue of Natural History relating that central american jaguars (Panthera onca) are especially drawn to the civetone in Calvin Klein’s “Obsession.” Good to know if you’re in search of big cats, but it still leaves the question of what civetone actually is and why it is important. For that, I turn to Richard Despard Estes Behavior Guide to African Mammals, in which he describes the olfactory communication of the animals;

Olfactory Communication: scent-marking with dung, urine, perineal gland.
Perineal-gland marks appear to be concentrated on trees fronting roads and pathways, especially trees that produce fruit eaten by civets. A passing civet pauses every 85m or so to press the everted gland against a trunk. The secretion is a thick, yellowish grease that hardens and turns dark brown and more visible with age, while the powerful and disagreeable scent remains detectable for at least 4 months. The musk scraped periodically from the perineal gland of captive African civets is refined into civetone, which “exalts” the fragrances of expensive perfumes.

Why not just cut out the middle-man and press a civet’s butt to your arms, neck, or chest? Such is what a cartoon (and rather low-quality article) from the Softpedia article “Get the best perfume from the cat’s a**” portrays. This is not entirely accurate as the civet’s secretions must be combined with alcohol and other chemicals to bring out its “pleasant musky odor,” but this does not change the fact that for centuries fragrance makers have relied on greasy secretion near a mammals anus to produce more pleasant personal scents.

Fortunately, synthetic civetone has been produced, but many “high-quality” perfume manufacturers still prefer scraping a civet’s musk glad the old fashioned way. From Yilma D. Abebe’s “Sustainable utilization of the African Civet (Civetticus civetta) in Ethiopia” (which is also found complete here);

Despite civet musk being produced artificially in the late 1940′s, high quality perfume producers still prefer the use of civetone (Anonis 1997). Demands for a synthetic alternative have been growing in recent years however with the British Fragrance Association (BFA) and the International Fragrance Association (IFRA) of the opinion that perfume industries are more likely to use artificial musk (Pugh 1998).

Indeed, the harvest of “natural civetone” continues, (despite some web sites suggesting that it has stopped with the invention of synthetic civetone) and while the African Civet is not threatened it does not change the fact that cruel practices have been recorded among civet farmers and wild civets are continually caught to replace those that die of stress in captivity (I’ll leave you to imagine why they’re so stressed).

The author also notes that local superstitions and husbandry practices make the trade very hard to regulate and control, and the process is considered unsustainable (although unlikely to stop because of economic gain associated with civet farms). Also of interest is the assertion that predominantly Muslim farmers in Ethiopia harvest civetone from civets. The author writes;

In Ethiopia, only Muslim communities are practice civiculture. According to oral history the legendary leader Nessiru Allah, who lived in Limu, Keffa, suffered from an eye affliction that was cured by an application of civet musk. Once cured, Nessiru Allah ordered followers of Islam to farm African civets (Mesfin 1995).

So what are we to do? Personally, I would check your own perfumes to see if “civetone” is listed in the ingredients, and even contact various perfume companies to see if they’re using civetone derived directly from civets and to ask for a ban on using the harvested secretions from the carnivores. Even if large companies switched over to artifical civetone, however, the practice would likely survive to some degree in Ethiopia and would be resistant to reform, so local and government workers would have to work with the farmers to ensure humane practices (i.e. scraping civet musk off bars or posts they deposit it on rather than sticking a spoon into the animal’s gland) and open up other economic opportunities so that the farmers are not relying on civets for income (even in the IUCN report mentioned above, civetone seems to be bringing in less and less money to Ethiopia). Such is the problem with humane practices and conservation, however; merely establishing the science aspect will not convince the farmer who needs income from his practices, and care for both the animals and people is needed if a positive change is going to be made.

End Note: Civets aren’t the only animals to be farmed for particular scents or secretions; bears and musk deer (also important to the fragrance industry) suffer similar consequences as well, and both will require seperate posts to do their stories justice.

End Note 2: I’ve corrected some of the mistakes I made in the initial post. I started getting a pretty bad migraine in the middle of writing this so I didn’t entirely pay attention to what I was doing. I’ll have some more posts up when I recuperate.





Had enough yet?

2 06 2007

Just in case you haven’t had enough of my photography today, Jeremy Bruno of The Voltage Gate has graciously put up some of my Red Panda photos from the Bronx, Philadelphia, and National Zoos. Some you’ve seen here, some you have not, so go check it out (and don’t forget to check out his posts on the cute little critters, too!)





More Zoo Photos; Bears, Peafowl, & Otters

11 05 2007

Last weekend some friends and I visited the Bronx Zoo (thanks Tim!) and I snagged a few shots; nothing incredibly dazzling or new, but I thought a few people might enjoy them. First up, a tiger I had not previously seen before, although I’m not sure whether this is one recently brought to the zoo or one that I just never ran into previously;

New Tiger

Tiger Drink

As always, the black leopards of Jungle World were fast asleep, although I did manage to get a halfway decent photo this time (although I’d need to remove the crease from the glass in the background);

Black Leopard

I did get to see the otters, however, which are not typically out when I come to visit;

Otter

The second time I ever visited the zoo I came across an amazing sight; two Blesbok fighting during the beginnings of a thunderstorm. Unfortunately I hadn’t seen them since then, but I did manage to get this picture during my last visit;

Blesbok

The giraffes were out as well, although none came close enough to get a decent shot;

Giraffe

And of course, I couldn’t not drop by to see the cheetahs;

Cheetah

The grizzly bears were still playing as well, this time sloshing about in their little pool;

Bears playing

My favorite shot, however, is of one of the animals that is so ever-present in the zoo I normally don’t take the time to photograph them; a male peacock. This one was having a rest under a bush and allowed me to get close enough to get a ground-level shot;

Peacock

So there you have it; like I said, nothing especially spectacular but a few good ones in the mix. I still love visiting the zoo, but when there’s hundreds of strollers being pushed about (and of course, half the children want to walk and not be in their strollers) it’s hard to have a good time. The zoo is free on Wednesdays, but unfortunately I must work and have to fight the crowds on the weekends. As cold as it was, I almost preferred visiting when it was 26 degrees in the middle of February; then it was just me and the animals and I could take as much time as I wanted. As a whole I don’t like zoos and their focus on money rather than conservation, but I am glad that I live close enough to one of the exceptions that I can visit almost anytime.





Marine mammals take another hit

20 04 2007

When marine fish stocks decline, pinnipeds (seals and sea lions) often take the blame. Seal hunters in Canada after (wrongly) accuse seals of eating all the cod and in the Pacific northwest of the United States it appears that sea lions are being blamed for depleting salmon stocks. I first heard about this issue in a book I randomly picked up in the Baltimore, MD Barnes & Noble a few years ago, and what scientists found was that the sea lions were not eating any significant amount of salmon, at least until a “fish ladder” was created to help the fish get upstream and they became easy prey.

Years later, the debate is still raging and now a sea lion in the Columbia river has been shot twice for stealing a fish off someone’s line (it appears from the article that the fisherman didn’t do the shooting, but it was another person in the area). It seems like the sea lion is alive for the moment, but this could very soon change as the bullets could cause deadly infection. What has yet to be proven, just like the passage in the book (I wish I could remember it’s name), is that the sea lions are actually a major factor in the declining salmon fishery, and I suspect that they are once again being used as a scapegoat for poor management and biological degradation. In all this talk not once have I seen the findings of an outside scientist (i.e. not affiliated with the government or National Marine Fisheries Service) as to what these animals are eating, and if it’s salmon, how much of their diet is composed of salmon. How can we make management choices, especially ones advocating lethal force on a species previously protected under the Marine Mammal Protection Act, without any serious study of what’s happening?

Others have noticed this issue as well.

“It won’t save declining salmon runs in the Columbia River, because the sea lions aren’t the problem.” said Sharon Young, national marine issues field director for [the Humane Society of the United States]. “It seems that it is easier to scapegoat the sea lions than to try to address these other more politically charged and complex issues.”

Recently, Japanese whalers have blamed Humpback Whales for declining fish stocks, but of course we already know their motives behind this statement; Humpbacks are next on the list to be hunted, which will likely cause greater outcry being they are one of the most powerful symbols of the ocean. Luckily, however, the case for further whaling is looking worse and worse and I hope it is entirely shut down soon.

In any event, I don’t believe marine mammals are having big impacts on fisheries like some claim, and in fact they actually help fisheries by eating competing fish and other predatory fish (especially in the case of seals and sea lions) so eliminating them would be a HUGE mistake. While I hope the issues in Oregon are resolved soon, somehow I get the feeling that as long as we have declining fish stocks, marine mammals are going to get the blame instead of mismanagement by humans.





Photos from the National Zoo; Pandas, Wolves, Gharials, and More!

15 04 2007

Looking back, Saturday seems like a dream. I’m sure part of that is due to the fact that I only slept 2 and 1/2 hours before getting up at 2 AM to drive to the National Zoo in Washington D.C. and spend the day with my wife and her parents. Lack of sleep aside, never have I been to a zoo with such wide species diversity, and while I still consider the Bronx Zoo to be the best I’ve ever been to, I was absolutely amazed by many of the residents of the National Zoo.

My wife and I arrived at 6:30 AM, hoping to see most of the animals in the zoo while they were still active. Unfortunately, most of the animals don’t make an appearance until later in the morning and the various houses didn’t open until 8:30 and 10:00 AM, so other than the occassional jogger there wasn’t much to see. Up in a tree, however, were two Red Pandas sleeping in, and here’s one of them in the early-morning light;

Red Pandas

A Mara, in contrast to the sleeping Red Pandas, was up and about;

Mara

Around the time that my in-laws arrived more of the animals were out on display, although before proceeding my wife wanted a picture of us together next to a statue of a sloth bear. Here it is, both of us looking rather unsettled because the sun was in our eyes and we were trying to communicate how to work my camera;

Us

One of my most favorite animals from the zoo was the Maned Wolf, although unfortunately their enclosure didn’t allow me to photograph them without a doghouse or chain fence in the background;

Maned Wolf

The miniscule Tammar Wallabies were also a highlight. Despite my appreciation for wildlife, every time I see them something in my head goes “Aww, whosanitsybitsy then?”

Tammar Wallaby

We also saw a rather old Spectacled Bear, and for some reason this particular one reminded me of Jeremy Irons. In any case, I have never seen one with an overall blond face (normally they have blond lines/patches that make them appear “spectacled”);

Spectacled Bear

I also finally got to see a Caracal in the flesh, although this was one angry cat. Frustrated that it couldn’t visit it’s other enclosure or get the birds on the outside, it wasn’t too happy when I stooped down to take its picture;

Caracal

Several cheetahs were also on display, a male desperately seeking the affection of this young female (although they were separated by a fence);

cheetah

I also got to see two 10-month old Bengal Tigers at the zoo, although their enclosure wasn’t exactly condusive to good photography. Here’s one of them after making an attempt to snag a bird that entered the enclosure;

Young Tiger

Speaking of young animals, two young sea lions were playing “king of the rock” in their enclosure;

Sea Lions

Two young otter brothers were also a bit scrappy, chasing each other about their enclosure and taking dirt/pine needle baths;

Otter

Other small mammals were also active during our visit, including a Banded Mongoose and some Meerkats;

Mongoose

Meerkats

Some of the local fauna proved to be just as interesting as the exotics; we spotted two white-tailed deer in the zoo as well as this small bird that had collected a flamingo feather for its nest;

Bird

I also finally obtained a photograph of one of my favorite animals, the Giant Elephant Shrew;

Elephant Shrew

While I am absolutely enthralled by mammals, I was also overjoyed to see a male and female Gharial up close in the Reptile House. Here’s the female, just before slipping into the water to join the male;

Gharial

The Great Ape House also provided for some good photographic opportunities, especially some young gorillas and an oranguatan that used some cardboard as a sun hat. In fact, many of the orangs at the zoo seemed to like cardboard as a hat, blanket, etc., which I had never seen before.

Gorilla

Oranguatan

Speaking of primates, this small tree shrew in the Small Mammal House slowed down long enough for me to get a good picture of it. Just seeing how it handled its food and used its hands left no doubt in my mind that primates are derived from such creatures;

Tree Shrew

I also encountered an animal I had never heard of before; the African Pygmy Falcon.

Pygmy Falcon

A Mouse Deer also made a brief appearance during our visit;

Mouse Deer

But what about the Giant Pandas? Well I was able to shoulder my way through the crowd of photographers and snag plenty of pictures of the young panda residing at the zoo;

Panda Sit

Panda Log

Panda Tree

Panda

While the young panda was certainly cute and very entertaining (i.e. watching a panda scale a tree for a good scratch), my most favorite moment from Saturday involved a female Mexican Wolf (a subspecies of Grey Wolf). When I arrived at the enclosure the three females were pacing back and forth near the back of their enclosure, stopping every now and then to look at my wife and I. There was no way I was going to get a good picture, but I discovered the cage was connected to another one the wolves could access, and after waiting a moment one of them came over to the front for a drink. After lapping up some water she took a long look at me and rejoined her pack, and here’s my favorite picture that resulted from my stroke of luck;

Wolf

While the 4 hour drive each way wasn’t very fun, I did highly enjoy myself at the zoo and hope to return soon. Even so, I would love to see these animals in the wild someday. While I certainly have some ok pictures, there’s not much of a story to them; “I walked by the enclosure and the wolf looked at me,” isn’t an experience that’s earned. Granted, in the wild I would get nowhere near as close to these animals nor be able to get them to “pose” for me, but I would much rather catch a fleeting glimpse of a wolf or jaguar than know they only exist in zoos and memories.








Follow

Get every new post delivered to your Inbox.

Join 25 other followers