Quick – which animal is most dangerous to humans in the United States? Ask State Farm, and they’ll tell you it’s the white-tailed deer, with about 150 people killed each year in auto accidents involving deer. Most lists cite mosquitoes (think West Nile), followed by bees (allergic reactions to stings), and brown recluse or black widow spiders. Domestic dogs kill about 30 people a year, horses and farm bulls about 20 each, while rattlesnakes and other venomous snakes (usually captive, handled snakes) kill about ten. If you mentioned bears, wolves or sharks, they don’t even make the list, though they always make a huge splash in the news.
Outside National Parks, bears tend to run from people, while wolves almost always flee, regardless of where you see them. Then there are moose. If moose don’t hear or smell your approach, they’re more likely to stand there, taking you in with that impassive gaze, assuming they acknowledge your presence at all.
Seemingly fearless, moose should be the thumbnail next to the entry “confidence” in the on-line dictionary. If their ears stay up, and they continue chewing, start snapping photos, but if their ears flatten and they stare at you directly, consider how to back away slowly, speaking in gently reassuring tones, while taking peripheral inventory of any large trees, shrubs or rocks, in case you suddenly require a shield.
Moose are far more likely to attack people than are bears. We have stereotyped Bullwinkle as large, bumbling, goofy and friendly. Don’t expect to see any Hollywood movies titled “Raging Moose Massacre” or “the Monster of the Ausable Valley.” What moose are, is incredibly interesting mammals, who face a bewilderingly complex mixture of hardships and challenges. Moose are tragicomic characters in Nature’s dance of life.
What are Moose and where did they come from?
Today’s version of the North American moose, alces alces, the largest member of the deer family, crossed the Bering Strait land bridge into North America about 10 to 15,000 years ago, a barely noticeable blink in the timeline of life on Earth, and at about the same time that hunter-gatherer Native American ancestors were coming across with their wolf-dog hunting companions.
Evolution itself is a blind architect, fated to perform modification only, never having that creator’s advantage of starting from scratch, with a blueprint not predestined by an existing structure. Moose speak to the imperfections of a process in which animals evolve in one ecosystem, and then expand into adjoining ecosystems presenting challenges for which they did not evolve, and are not prepared.
Moose are enormous, herbivorous ungulates, with large males and females weighing in at about 1,500 and 800 pounds respectively. In taxonomy, the lumpers seem to be getting the upper hand on the splitters these days: Bergmann’s rule describes how individuals within a species are somewhat larger on average in colder, more northerly latitudes than in milder climates, because natural selection favors animals with a larger body mass to body surface area ratio, as they are more effective at retaining heat, and therefore more likely to survive Winter’s hardship, when the gauntness of starvation, is joined by hypothermia. Generally speaking, Alaskan moose are larger than New England and Eastern Canadian moose, which are in turn larger than moose found in the Yellowstone region.
Moose in the northeast are darker in color. Cows have brownish noses, bulls black. Western moose spend more time out in the sun, and have a brownish saddle for reflecting sunlight.
A Moose’s Life is one Endless Quest for Food
There’s much to recommend the vegan diet, but one shortcoming for herbivores in the wild is the relative lack of nutrition in their diet. As a result, moose have to make up in quantity what they lack in quality. Adult moose consume about five tons of vegetation per year. Try to picture how much food this is: when you drive down the Northway, and see those huge cylindrical bales of hay in the farmer’s field, each of those weighs about 1,000 pounds. Imagine eating ten of those, at an average of 30 to 40 pounds per day.
The moose diet ranges from balsam fir, white and jack pine, and the stems and bark of deciduous trees and shrubs in winter, to the leaves and stems of willow, aspen and birch, as well as aquatic plants in summer. Winters are more challenging, and moose are lucky just to eat enough volume to make it through to spring. Like trees, moose don’t really grow in winter, making up for it in summer, when they become eating machines, right up until the rut begins in September.
In summer, moose spend about eight hours a day chomping on fresh vegetation, and another eight hours ruminating, chewing again food brought up from the fore stomach, or rumen, one of four different chambers in the moose’s stomach. Aquatic plants fill the sodium deficiency in moose diets, which is why we sometimes see them road side in winter, licking the rock salt we use to melt winter ice, and coming through the windshield of unwary drivers. The lips of moose are prehensile, and their nose configured in a manner that allows them to swallow while underwater, a process not fully understood yet, but a great advantage to an underwater browser.
Moose spend so much time eating, they’re not great wanderers, and a moose who lives to the ripe old age of fifteen or twenty, may not be more than fifty miles from where they were born. The fates of moose and browse targets are inexorably intertwined. Forests thrive in areas which suffer wild fire about every 50 to 100 years. Moose thrive in areas of fresh burns, which can lead to willow, aspen and conifer eruptions, as well as in areas browsed out and long abandoned, allowing vegetation recovery.
Where moose populations are water or land locked, in other words, where habitats are not connected by natural corridors enabling the flow of wildlife from one habitat to another, not to mention a healthy exchange between gene pools, a growing moose population may cause its own correction by over-browsing, causing a collapse in the abundance of browse, followed by a collapse in the now starving moose population, whose increasing mortality rate makes the wolf’s efforts at survival much easier and less dangerous, as they can avoid the dangers of the hunt by scavenging dead moose, leading to an uptick in the pack’s numbers, and so on, as the circle of life rumbles on.
The scarcer browse becomes for moose, the more likely they are to stand their ground at a feeding location, when confronted by people or wolves. Since moose weigh in at anywhere from ten to fifteen times the size of the average gray wolf, and defend themselves very well with powerful kicks delivered with sharp front and rear hooves, wolf packs carefully test moose for vulnerability with the result that, on average, wolves actually choose to attack only one in every twenty moose they approach. Healthy moose between the ages of about two and ten are relatively safe from wolf attacks, as the challenge they present to attacking wolves is not worth the risk.
Mammal hides generally, and moose hides in particular, are very efficient at retaining heat, even during the coldest winters. After shedding their winter coats, moose consider fifty degrees the optimal temperature. Being in the lake or bog gives them relief from the heat and biting insects, and because they can stand comfortably at depths where wolves would be at a disadvantage in any attack.
Moose Romance and Mating
Moose are solitary creatures, and don’t generally herd up the way elk and caribou do. During most of the year, bulls tend to live alone, and in an almost comical rebuke to Intelligent Design, spend 25% of their annual energy input growing those absurdly massive antlers, which may top out at 50 pounds. Antler growth begins in the Spring, and the bulls use them during the brief rut season in Autumn, not only to contest mating rights with other bulls, but as display evidence for cows, sort of the moose equivalent of showing off a flashy car or mansion, a clear indication of their strength and suitability as progenitors for healthy calves.
Moose courtship is, well… earthy. Bulls sport a fleshy appendage under the jaw called the rope and bell, the size of the bell being one sign of maturity, while females have only the rope. The rope and bell may freeze and drop off in a very cold winter. Ouch! The purpose of the bell seems to be to excite females during the rut. Bulls churn up the soil with their front hooves, urinate in the resulting pile, vigorously mix it again with their front hooves, and then splash it with their hooves, as though stepping through a spray of perfume, before rolling the bell back and forth through the muck for a final dose. Cows will push and shove each other for the right to roll in this cologne, while the bulls display upwind, tilting their heads to show off the size and breadth of their antlers, and shaking their bells, wafting that fragrance to the aroused cows.
The size of a bull’s rack is not only an indication of overall health, and the ability to locate and exploit superior browse, it’s a sign of maturity. Dominant bulls will end up mating with multiple cows, while younger bulls practice harmless antler sparring with accommodating older bulls with larger racks. Mature bulls tend to be seriously challenged only by bulls of comparable size, and serious combat, involving antler punctured torsos and injured limbs may result. Many bulls become so exhausted by the rut, they fall prey to wolves, who quickly recognize weakness, injury and vulnerability.
Bulls may cluster before the rut for playful, tune-up sparring, and after the rut, when their condition, weakened by fasting and violent encounters with other bulls, not to mention the seasonal shedding of their antlers, may provide safety in numbers. Cows are naturally very protective of their calves, and will drive away predators and other moose, the latter in response to defending food sources. Ask any wolf who’s had his skull caved in by Mama Moose’s sharp and heavy hooves, when they got too aggressive with her calf. Like all ungulate calves, moose need protection as they’re only about 30 pounds when born in May, bulking up to about 300 pounds within six months to be prepared for the hardships of winter.
One interesting aspect about moose calves, as well as the young of other ungulates, like deer and elk, is the fact that they are nearly odor free, thanks to natural selection. The calves with more odor get discovered and eaten, those with less grow up to breed, and pass along the “less stinky” gene, so that after thousands of generations of this tendency, the survival strategy of fawns and calves is to lie still in the tall grass, while Mom is off browsing. That way, the grizzly has to literally step on the calf to earn a meal. How does the enterprising grizzly in Yellowstone, for example, get around this? After observing the cow, browsing off by herself, away from the herd, he concludes there is a calf, and he walks in a concentric circle towards the middle of the tall grass or shrubby area, until he steps on the calf. Just when you thought bears were stupid!
Moose tend to struggle more through a winter of deep snows, as their relatively heavy torsos and sharp hooves force them to pole through snow, while wolves not only have snowshoe-like paws, which enable them to distribute their weight effectively, allowing them to run on top of compacted snow, but share the burden of breaking through lighter, deeper snow by following in each other’s wakes, and taking turns leading the pack.
Moose have the advantage when the snow is less than about two feet deep, as they’ve evolved a specialized trot, which uses their long legs and high torsos to seem to float above the shrubs, rocks, downed trees, and the other obstacles encountered during their flight from predators. In addition, they are able to bound over natural barriers that wolves and bears would be forced to run around.
Once the snow exceeds two or three feet, the moose are more likely to defend themselves where they stand, and the advantage goes to the wolves, as long as they can avoid being kicked in the head or rib cage. There are stretches of winter when heavy snows force the moose under sheltered areas, such as the Adirondack forests of white and red pines, where much of the snow remains in the branches, and the moose can “yard up”, the way white tailed deer do. The trade-off is that this area may not be the most efficient place to browse, as the thicker the canopy, the fewer deciduous saplings and shrubs are present to provide the inefficient browse of woody stems and twigs. At the same time, the expenditure of energy to get to a better browse area may not be worth it, and Bergman’s Rule may come calling with a vengeance.
Be careful where you move to
One of the more interesting aspects of an ecosystem is the endless complexity of the relationships between flora and fauna, as well the macro and micro worlds. Each of us is actually a small community in which we may occupy the starring role, but are helped, as well as exploited, by a bewildering array of parasites and symbiotic partners.
As an example, I have some disturbing news: even if you brushed your teeth this morning, you still have about 50 parasites in your mouth, some of which are beneficial, but many of which are better for your dentist, and the higher bill you’ll pay when you visit them.
When a friend quips that his stomach “is talking to him”, he might have said instead: “did I ever tell you that I have billions of anaerobic bacteria in my gut and stomach, and they’re the ones actually doing the digesting. There’s no chance I could do this on my own”, an observation that gives new meaning to the phrase, “Everything in Nature is connected”.
What about external parasites like black fly, mosquitoes and ticks? We may not like what they do, but they are playing a role in nature, just not one that benefits us!
White tail deer have been evolving in North America for 4 million years, while as noted, modern moose crossed the Bering land bridge into North America only about 15,000 years ago. Think about that disparity for a moment.
Being a curmudgeonly fellow, I sometimes debate evolution with friends whose objections are not rooted in religious fundamentalism or other aspects of our belief systems not related to science, or the threads of evidence science may provide. The real difficulty may be that while we can conceive of long stretches of time, for example, 4 million years, we can not imagine it… we can’t get our minds around it. We’re lucky if we individually live 90 years. When we try to figure out our own family tree, we usually stumble after five or six generations. Life on earth is nearly 3 billion years old! Evolutionary processes can be excruciatingly slow… how many generations of white tails are represented by 4 million years? In the course of evolution, 15,000 years is a mere speck in time.
The other aspect of evolution that is hard to grasp, is the relentless competition, the types of behavior and adaptation that enable a species to survive, not just in adversity or cooperation with other species, but in relation to our own collection of parasites, our helpers and hinderers. When your competitor develops an advantage, you respond and adjust successfully, or you join the 99% of animals that have lived on earth, who are no longer with us. As said elsewhere, nature is not “fair”, and it is certainly not a democracy.
Deer carry parasites meningeal or “brain worm”, giant liver fluke and the winter tick, parasites which deer are able to live with. Moose sharing habitat with deer, pick up these parasites, and being relative newcomers to our neck of the woods, fare less well. Brain worm and liver flukes are passed to moose through a cycle involving deer droppings, snail infection and the ingestion of leaves contaminated by deer pellets or snails.
Brain worm, which produce larvae on the surface of the white tail brain, work through the moose brain tissue, destroying the brain, and causing weakness, reduction of equilibrium, disorientation and often death in moose. Flukes are rarely fatal, but can work with other health issues to weaken moose and make them more vulnerable to wolves and other natural fates.
Deer are excellent groomers. A white tail deer will pass through winter with up to 300 ticks, but can detect and remove most of the newly hatched seed ticks through licking and rubbing when the ticks climb aboard in autumn, often in clumps, from vegetation brushed by the deer. The ticks are aided in this boarding strategy by their ability to detect the carbon dioxide exhalation of approaching mammals, and the fact that excited ticks can quiver, cluster, shake and flip onto the unfortunate moose, sort of like dog fleas at their own disco.
For some reason, moose do not feel the ticks, until they have climbed up the torso and the female ticks begin biting and drawing blood, as part of their reproductive cycle. The winter tick passes through three developmental stages while on the moose, each of which involves taking blood from the moose.
By January, an adult moose may be carrying anywhere from 10,000 to 80,000 ticks, and while an individual tick takes an insignificant amount of blood, moose can reach a tipping point where the ticks are removing a significant amount of the blood generated naturally by bone marrow and hematopoietic cells, leading to loss of energy.
In addition, the itching caused by ticks and mites lead the moose to bite at their itchy coats, and vigorously rub their bodies incessantly against rough-barked trees, like white and red pines, leading to coat loss and possibly hypothermia. These factors, when combined with the lower nutrition intake of moose in winter, which, following Bergmann’s rule, exposes the moose to possible starvation, threaten the moose’s life, making the stretch between mid-March and mid-May the most vulnerable period in an adult moose’s year.
Warming climate enables greater numbers of winter tics, which may help explain why moose are in decline in much of their range, including New Hampshire, Vermont and Minnesota. (New York Times, Oct 14th, 2013: Moose Die-Off Alarms Scientists).
Moose and Wolves
Just as our visual acuity, and more precisely our ability to resolve color, is probably our most important sense when it comes to memory, it’s not too much to claim that while sharp eyesight and keen hearing are indispensable to wolves, to a large extent the world comes to wolves and other canids principally through their noses. After bears, wolves have the most efficient and sensitive noses in the mammal kingdom, and use that powerful information gathering tool, to read the olfactory record of the comings and goings of prey animals, as well as poaching competitors like bears, coyotes, bobcats and other wolves.
Because wolves can distinguish different moose in their territories by smell, and because they assess their chances against individual moose by testing them, they develop a history with each moose, such that they can elect to approach or avoid any particular moose they see or smell.
As noted, moose spend so much time eating that they’re not great wanderers, and may not move more than about fifty miles from the area of their birth, a distance your average wolf pack may travel in a single day, during the course of exploring their territories for moose and other prey. Because wolves tend to defend huge territories, averaging about 200 to 500 square miles, an individual moose could spend its entire life within a given pack’s territory.
Wolves concentrate their territory defense by spending more time patrolling their territory’s periphery, and may pass through any point on that periphery every two weeks or so. In that sense, the moose might as well be the Statue of Liberty, and the wolf pack may as well be on that tourist boat that goes around Manhattan Island, because they keep running into the same moose in the same general area.
It’s tough being a Moose!
But, alas, moose have much bigger problems in nature than living among wolves. Half of all moose develop arthritis by age ten, due to a combination of genetic predisposition and maternal malnutrition during pregnancy, and the fact that moose spend so much time standing and eating, supporting those large torsos on their legs. Cartilage in the knee and hip joints breaks down, leaving the moose in pain, hobbled by swollen joints, and, again, vulnerable to attack by the ever testing and investigating wolves.
Jaw necrosis is another common fate for moose. Moose haven’t learned how to floss yet, so the constant overuse of the jaw, and the fact that moose are often reduced to chewing on leafless, deciduous stems and shoots in winter, results in the jamming of woody material between the teeth. The moose will use its rough tongue in attempts to dislodge the material, but if it begins to break down and rot, the jaw may become infected and weakened, leading to jaw fracture during mastication, dooming the moose to slow starvation. Starvation is the number one killer of all wildlife, moose included, and sometimes the intervention by wolves may interrupt a slow and horrible process.
What’s the story with Adirondack moose?
We all love to see and photograph moose, and if you’re involved in tourism or hospitality in the Adirondacks, you know that moose mean tourist dollars, and another notch in our “Forever Wild” belt. More moose could eventually mean wolves and cougars, and other proven tourist magnets. The wolves of Yellowstone, by themselves, add $30 million in revenue annually to the tourist towns surrounding Yellowstone. So… the apparent decline of moose is not a good thing.
I asked Ed Reed a Wildlife Biologist with the DEC, and our local expert on the moose, what gives:
“We have seen all of our annual moose population indices, including mortalities, aerial surveys, and hunter survey, level off since about 2006. The reasons for our population not increasing as expected are unknown at this point, but we initiated a moose research project this winter in cooperation with ESF, Cornell, and WCS, to get a handle on moose numbers and population trends. The research will involve aerial surveys, DNA analysis from scat collections, gps collars, and possibly some other methods. The field work for this project will begin in earnest next winter, but we are actively trying to collar moose right now.
“Winter ticks have been found on a few moose in the southern part of their range in NY, but not in the Adirondacks as yet, so I suspect they are not a factor now.
“Declines in moose numbers in other states are also under investigation, but no scientific studies to date have identified a root cause. Some researchers suspect a warming climate to be a contributing factor, but the data so far does not confirm that.”
In short, moose in North America are still strangers in a strange land, and have to overcome significant hardships to survive. No wonder they always look like they have a chip on their shoulders.
Photos: At the top, “Bruce the Moose” by Brenda Dadds Woodward, west branch of the Ausable, Wilmington, 2012. Two photos of bull moose afflicted with winter ticks taken at Algonquin Park, April 2014, by Steve Hall. The two photographs of Cow moose with twin calves, as well as the new born calf are from the Kenai Penninsula in Alaska, by Steve Hall, May 2012.
Further reading on Moose: Ecology and Management of the North American Moose, 2nd edition, edited by Charles Schwartz, Edward Franzmann and Richard McCabe; and Moose: Behavior, Ecology and Conservation, by Valerius Geist.