It's been a year now since I last posted here, a very busy year indeed. We survived a forest fire, I became VP of a wildlife rehab non-profit, and many injured and orphaned animals have made their way through my care and back into the wild. I did have one animal who was not releasable. Yogibear the raccoon was, from the moment I got him, 'slow'. He was slow to hit his basic developmental milestones - slow to walk, slow to climb... and he never reached the level of skill needed to survive in the wild. So, after trying everything I knew and consulting with other rehabbers, I decided to keep Yogi as an educational animal. All was well until last week, when I went on vacation and left him in the care of a housesitter, a person who was educated in wildlife care and management and even works at a local wildlife center. However, because Yogi was so tame and sweet-tempered, she let her attention wander one day and he ran away, into the woods behind my house. I panicked, sent frantic emails to neighbors - and my entire neighborhood mobilized to rescue my baby. After two days, Yogi showed up at a neighbor's house, hungry and lonely, and was brought safely home. Yogi made this video to thank everyone.
We often classify animals according to what they eat, as a sort of shorthand for describing what kind of animal they are. The three basic classifications we use are herbivore (plant eating), carnivore (meat eating), and omnivore (will eat both plants and meats). With each category are sub-categories that are more specific: for example, within the herbivore category are the frugivores, which eat only fruit, and folivores, which eat only leaves (not grasses). Within the carnivore section are various levels of meat-eating. Animals which need meat in order to survive, but can also consume plant matter (although they get very little nutrients from it) are called obligate carnivores. Animals that can *only* consume meat are called hypercarnivores. Interestingly, the hypercarnivore classification does not include most of the major predatory animals – hypercarnivores are usually birds of prey and water-dwelling species, such as certain fish, snakes, dolphins, and octopi.
The last category is the broadest, and the one to which man belongs: omnivores. Many people mistakenly think that omnivore means that the animal will eat anything. But what it really means is that the animal is capable of extracting nutrition from both plant and animal matter. A common example of an omnivore would be the raccoon. Raccoons are very successful at adapting to living with humans, in part because they can adapt to eating human foods – more specifically, in urban areas they usually eat trash and/or pet food. But in areas away from humans, raccoons can be very picky about their diet. They will catch and eat small fish and frogs, and the also like to eat insects, worms, and snails. All these are a form of meat. Raccoons also eat plants, roots, seeds and fruit, which are all plant matter. But other omnivores are not so wide-ranging in their abilities to extract nutrients from different sources. Humans, for example, do very poorly at extracting anything useful from cellulose plant material, like bark, wood, and grass. We also do not get very much nutritional value from eating insects. So being omnivorous does not mean that an animal can survive on a diet of anything – it just means that the animal is capable digesting both meat and plants, to a greater or lesser degree.
There is very frequently overlap between the carnivore and omnivore category. Bears are a particular problem. Technically they belong to the order Carnivora, but they are largely omnivorous. The polar bear and the sloth bear (which eats only termites) are two true obligate carnivores in the bear family. But, due to details of their teeth and their ancestry, bears remain in the carnivore category in terms of their taxonomy, but are considered omnivorous in the common sense of the word. In the same vein, squirrels, which we think of as primarily eating fruit, seeds, and vegetables, also eat bird eggs (considered meat), bird fledglings, insects, and sometimes small reptiles. So while they technically fall into the herbivore category, their actual eating habits are omnivorous.
We can see that these three categories are flexible in the common usage. In taxonomic usage, they refer not only to what the animal has been observed eating, but to internal organs, skeletal and tooth structure, and ancestry. This can be confusing to the non-scientist, but neither usage is ‘wrong’. The ‘correct’ assignment of an animal to a particular category depends on the context, and for most people the context is not a strictly science-based one. Therefore, in common usage it is not incorrect to say that bears are omnivores, or that squirrels are herbivores.
The question that plagues many humans is, are humans omnivores or herbivores? The scientific answer, based on dentition and internal structures, is that humans are omnivores. But remember that omnivorous does not mean ‘will eat anything’. Omnivores are capable of digesting plant material and meat. But that doesn’t mean that they need both plant and animal matter in their diet. Many omnivores eat a mostly plant-based diet, while many lean more towards the carnivorous side. Many have diets that change according to the season, or their location. Humans, as omnivores, can choose if they want to eat a plant-based diet, a meat-based diet, or something in between. The omnivore category does not limit us in terms of diet - it gives us the broadest possible choice.
One of the wonderful effects of our ever-increasing technological know-how is that we can now explore worlds that we have never been able to visit before. No, I don’t mean distant planets, but worlds that exist right here on Earth – isolated mountaintops and valleys, the canopies of the cloud forests, and inhospitable regions previously inaccessible. But perhaps the most amazing new universe we have discovered on Earth is that of the ocean. The ocean covers 75% of the surface of the earth, but until recently, we have never been able to explore its depths. We have had to make guesses about what it is like at the bottom of the sea, and what might live there, based on tiny bits of information – a carcass washed ashore, a strange creature brought up by fishermen, a skeleton of something we can’t identify.
But due to huge advances in underwater technology, robotics, and imaging systems, we can now visit the deep parts of the ocean. We can now go down to the sea floor in many areas, in depths of such crushing pressure and total blackness that we had always thought that nothing could survive there. The premise that we humans operated on was that nothing could survive without sunlight of some type, and that the pressure would be too great for life to succeed. We envisioned the sea floor as a desolate, empty expanse of rock and sand.
And how wrong we were! The lower depths of the ocean are absolutely teeming with life, in shapes and sizes previously unimaginable. Consider the giant squid. This creature was known only from a few incomplete carcasses brought up by fishermen, and for some time was considered a creature of legend, not even real. But now we have seen amazing underwater footage of this animal, confirming the existence of an animal that can reach over 40 feet in length. The giant squid lives deep in the oceans, only rarely surfacing, and it wasn’t photographed until 2004, with video footage taken in 2006, only five years ago. Other animals only recently discovered include an octopus that imitates other fish, so as to sneak up on its prey (the mimic octopus); a crab covered with spines that look like hair; a snail that construct its shell out of iron and is magnetic; and a fish that has a completely transparent head and can rotate its eyes 90 degrees, from looking straight ahead to looking directly overhead. There are tube worms eight feet long that live in volcanic vents on the ocean floor, at temperatures of over 600F. Jellyfish with tentacles 12 feet long swarm under the Antarctic ice; and eerie glow-in-the-dark fish with huge teeth patrol the ocean floor. Some of the new discoveries are so strange that no one is even sure if they are plants, animals, or something not yet defined.
While most humans dream about the possibility of life on distant planets, deep-water biologists are discovering new forms of life right here on our own planet. Every discovery they make expands our ideas of how life evolved, what conditions can support life, and how we categorize life. While looking to the stars and dreaming of new life is fun, what is even more amazing is looking to our oceans and actually finding it.
In honor of Endangered Species Day, May 15, I have reposted two of my previous articles that address this critically important issue. (Don't worry, I don't make a habit of reposting, and we will have new content next Thursday, as always.)
Orange Band was a Dusky Seaside Sparrow, a small and somewhat drab bird that lived in the Florida wetlands. He was named for the orange identification band on his leg, and he lived to be very old for a sparrow – he was at least eight years (the amount of time he had been in captivity) and possibly as old as twelve. Either way, an ancient age for a sparrow.
Perhaps Orange Band knew, somewhere deep within him, that he carried the weight of his entire species, and that his death would sound the knell of extinction. In 1987, Orange Band died, and with him died the Dusky Seaside Sparrow. He was the last of his kind, and the Dusky Seaside Sparrow is no more.
In Robert James Waller’s book of essays, “Old Songs in a New Café”, he writes a thoughtful and heart-felt essay about Orange Band, made even more poignant now by the fact that Orange Band was still alive when he wrote it. I am ashamed to admit that I don’t remember the essay that well, only that it moved me, but part of it that I remember is Waller wondering what it would be like to be Orange Band. Not to be a sparrow, necessarily, but to be the last of your species, and to know that the light of the whole history of your species’ time on earth would go out with you.
We all worry about the extinction of species in the abstract. But for a moment, let’s imagine the extinction of man. Not in a Will Smith “I Am Legend” kind of way or in a “nuclear holocaust kills everyone” kind of way, but in the way that most species go extinct: quietly, with little or no fanfare, with no one to witness the final death. A quiet, unnoticed, everyday vanishing.
Imagine yourself, perhaps sitting in a field, your back up against a warm brick wall, or maybe you are under a shady tree. The world is going along without you, there are still birds and fish and trees, there is just no place for you left in that world. There is no place for you to live, no place that welcomes you, no place that you can call home. You haven’t seen another of your kind since childhood, maybe never. You don’t know what happened, or when, or how it came to be that the earth no longer has a place for you. All you know is that you’re tired, and it’s time to put down your burden.
Of course, Orange Band was not thinking these thoughts, because he was a sparrow. And the last Golden Toad, the last Pyrenean Ibex, the last Hawaiian Crow, the last Baiji Dolphin, the last Red Colobus Monkey (all extinct within the past ten years) were not thinking those thoughts either. But since they couldn’t, maybe we humans owe it to them to think those thoughts for them.
Here is one last thing to think about: The Dusky Seaside Sparrow did not go extinct due to being hunted, the cause of so many extinctions. No one wanted his feathers, no one wanted to eat him, no one particularly even wanted him out of the way. The species went extinct due to habitat destruction, the single largest cause of extinctions today. And in a horrible irony… the habitat was destroyed to make way for the Kennedy Space Center. We humans killed off a bird in our quest to fly. We didn’t know we were doing it, and by the time we realized it was too late.
The IUCN (International Union for Conservation of Nature) is the international scientific body that tracks the statistics relating to endangered species. At the end of each year, the IUCN compiles all the data for that year and compiles the “Red List”, a listing of endangered and critically endangered animals. The list also contains comparisons to prior years, so that the progress of each animal can be traced over time. In order to create the list, they do ongoing studies of each animal that they are evaluating and determine the overall population, how much that population has increased or declined, and what the ‘normal’ populations of the animal should be. Based on these statistics, they assign each animal a category. The categories are: Extinct, Extinct in the Wild, Critically Endangered, Endangered, Vulnerable, Lesser Risk Conservation Dependent, Near Threatened, and Least Concern. Of these categories, an animal in the Extinct in the Wild, Critically Endangered, and Endangered groups is considered ‘threatened’.
So in 2008, how have we done in preserving our threatened species and preventing others from moving into threatened status? Sadly, we have not done well at all. Better than other years, maybe, but overall our efforts to protect endangered species continues to fall woefully short.
There was some good news in 2008. Thirty-six endangered mammals increased their numbers and moved down a category. The re-introduction of the black-footed ferret, formerly extinct in the wild, was declared successful, moving it from Extinct in Wild to Endangered status. The wild horse, as well, moved from the Extinct in Wild to the Critically Endangered group. Several species of whale moved from Lesser Risk/conservation dependent to Least Concern; seven species of bat left the threatened list and moved into the Nearly Threatened or Least Concern groups. The Indian Rhino made it from Endangered to Vulnerable, and the African Elephant made it from Vulnerable to Nearly Threatened.
Thirty-six mammals sounds like a good number – until you realize that 143 mammals showed a decline in numbers sufficient to move them up a category. Seven bat species left the threatened list… but 21 joined it, with three more upgraded from Vulnerable to Endangered. The Indian Rhino was downgraded, but it was too late for the Western Black Rhino, the Javan Rhino, and the Sumatran Rhino, all considered Extinct in the Wild. Eleven monkeys moved to threatened status, in addition to another three that moved from Vulnerable to Endangered. Twelve squirrels also joined the threatened list. A total of sixteen mammals were upgraded to Critically Endangered level, including the Woylie (a type of bettong), which made a leap from Least Concern to Critically Endangered in one year.
Birds fared worse. Only two species showed any improvement, and 23 moved up on the list, six of them moving from Endangered to Critical. Reptiles had no improvement at all, and four tortoises, a turtle, and a crocodile moved into the Critical category. Information on amphibians is not yet finalized, due to difficulties with the statistics from South America.
So, what can we do? There are countless ways that every one of us can help. We can all try to live a little more lightly on the earth, consume a little bit less resources, to help prevent habitat loss, one of the main causes of extinction. We can donate time or money to organizations working to help, such as the World Wildlife Fund or the Nature Conservancy. We can do our best to educate our friends and family about conservation issues. We can be careful where and how we go on vacation, to limit our impact on potentially fragile environments. And we can keep an eye on our own backyards – make them wildlife friendly, if possible, or at least make them as close to the natural environment in your area as possible. And be kind to the little guys, as well – insects and worms deserve their place in the world, too.
Most of all, do not give up. The 38 species that gained some ground may not sound like much, but for those 38 species, the world has gotten a little better, a little friendlier, a little safer. And that, after all, is the goal we all strive for, for ourselves and for our animal brethren. So Happy Endangered Species Day to you, and while you are celebrating, raise a glass to yourself and all the people like you, who helped to bring a happier 2008 to the Wolverine, Black-footed Ferret, Juan Fernández Fur Seal, Guadalupe Fur Seal, Bowhead Whale, Southern Right Whale, Humpback Whale, European Bison, Spanish Ibex, Walia Ibex, Przewalski's Gazelle, Pyrenean Chamoix, Gray Whale, Ryukyu Flying Fox, Pohnpei Flying Fox, Samoan Flying Fox, Rafinesque's Big-eared Bat, Townsend's Big-eared Bat, Geoffroy's Bat, Gray Myotis, Western Quoll, Lumholtz's Tree Kangaroo, Western Brush Wallaby, Burrowing Bettong, Daintree River Ringtail Possum, Herbert River Ringtail Possum, Wild Horse, Mountain Zebra, Indian Rhinoceros, Black Lion Tamarin, African Elephant, Eurasian Beaver, Greater Stick-nest Rat, Shark Bay Mouse, Western Mouse, Speckled Ground Squirrel, Washington Ground Squirrel, Little Spotted Kiwi, and Marquesan Imperial Pigeon.