In New England, an American pine marten is searching for food in a pile of deciduous leaves on the forest floor, nimble and always curious.
The animal's high metabolic rate means that they are constantly looking for food, up and down the trees, and voles are their preferred delicacy.
Playing hide-and-seek with an American pine marten can be a protracted battle. Effortlessly traversing the ground and treetops of temperate and boreal forests in the north, pine martens are "shadowless, no-trace" animals – their metabolic rate is so fast that they doom their lifestyle to madness.
Their constant need for heat means that these solitary predators spend most of their waking hours sweeping their forest homes in search of food.
In the height of summer, when food is at its most abundant, they may work for 16 hours. American pine martens perform best in calm forests, where the ground is littered with dead wood and trees
branches, it's also easier to find their favorite prey.
These light carnivores – weasels like stoats and weasels – have a wide range of prey, including hares, squirrels and birds, but voles are their favorite, finding them in a wide variety of species on the forest floor.
There are a large number of forest predators capable of catching voles, but the American pine marten can be said to be invincible, thanks to their size. The pine marten's slender, flexible body and short legs are ideal for shuttling between branches, climbing trees or chasing squirrels, and their size is also ideal for traversing narrow gaps, cracks and tunnels to catch small prey.
When a pine marten tracks and chases a vole, it is nearly impossible for the vole to escape. But having the ideal vole predator size comes at a price, and a long and narrow body means having a small stomach.
Therefore, pine martens cannot gobble up even if they are successful in hunting, so when winter strikes, they cannot rely on limited fat reserves to survive the winter.
The elongated body also has a high surface area/volume ratio, which means that pine martens lose heat much faster than the short, fat and broad body with a hypothetical low surface area/volume ratio.
Like all warm-blooded animals, the only way pine martens generate heat is by burning energy. This means turning voles into energy.
This is not a problem in summer, when prey is usually abundant, but in winter, temperatures in boreal forests can drop to minus 20 degrees Celsius. With no fat reserves, pine martens can't hibernate like some other mammals and continue to find ways to feed.
In order to survive the cold winter, the American pine marten really has "two brushes". First, their thick fur to a certain extent compensates for the defects caused by the huge body surface area.
When the temperature plummets, they are able to seek shelter in a snow cave, much like a polar explorer, unknowingly entering lazy mode to conserve their strength.
The thick snow has little effect on the pine marten's movement, as their big hairy feet help disperse their weight, allowing them to jump almost freely on the surface of the snow.
But the snow does add another layer of protection to the pine marten's prey, making hunting more difficult.
In winter, pine martens have to become predators in the world under the snow, especially in the spaces formed around low-hanging branches, wood and other piles of wood, where voles are still active frequently.
Wherever pine martens find vegetation sticking out of the snow, they stop and follow the vine to find the entrance to the space under the snow. They then use their keen sense of smell and hearing to detect voles — usually, 1/10 of the holes contain voles.
Field mice are usually very rare in winter, so pine martens also search for carrion – possibly frozen animals. But larger predators, such as steppe wolves and foxes, also seek out these animal carcasses and see them as competitors if they don't eat pine martens.
The pine marten's only way to escape is to run towards the trees. In fact, scientists now believe that Songshao's tree-climbing skills are more like habits developed by avoiding predators than hunting prey that inhabits trees. #Headline Creation Challenge# #科普 #
