Winter World_ The Ingenuity of Animal Survival - Bernd Heinrich [110]
I contrast now the behavior of the gray jay with another animal that also survives the winter only because of the energy resources it collects during the summer months. This animal’s social system is also crucial for making the storage of food energy possible. However, there is one large difference between it and the gray jay. In this animal only the mother survives the winter, along with her tens of thousands of daughters. The male offspring, who are unable to feed themselves, get kicked out of the warm nest or are starved in the fall by not being regularly fed. In this case, unlike with the gray jays, all the daughters participate in helping the mother rear subsequent broods of offspring. What I’m talking about, of course, are honeybees (Apis mellifera).
Honeybees manufacture a special product with a high energy content that has a nearly indefinite shelf life in the well-regulated microclimate of their nest. The raw material for honey, nectar from flowers, is carried in a unique distensible stomach that serves as a large bucket. The pollen or “bee bread” used to feed the young is packed into a special hair-structure on each hind leg. The bees make wax, and use it to build finely crafted receptacles to the most precise specifications to store the honey and the pollen, but separately. A colony of honeybees may routinely store a hundred pounds of honey (plus numerous pounds of pollen) for the winter. Special climate-control mechanisms are employed to maintain the wax receptacles holding the honey and/or pollen at precisely the right temperature, to keep them from melting while also soft and malleable enough for shaping. Ventilation and proper humidity control are used to concentrate the honey and control molds. Special orientation mechanisms involving a superb internal time sense allow the bees to use the sun as a reference point to navigate quickly and efficiently between foraging and the food storage sites at the nest. As a result of their superb energy-storage mechanisms, honeybees are the only insects in the north that don’t hibernate and that maintain a high body temperature all winter long. Bumblebees, which also collect honey and pollen and which individually work longer and faster than honeybees, do not lay up food stores for winter. There is no need. They only store for a rainy day, converting their wealth directly into offspring, then the colony disintegrates in the fall and only the fertilized females (new queens) stay alive to hibernate in cold storage in the ground.
As I sit here at my house in Vermont, next to my four beehives in mid-August, the goldenrod in the neighbor’s fields is in full bloom and my bees are busily harvesting nectar from it to make honey to fuel their energy metabolism through the winter. Pollen is collected often simultaneously with nectar, and this pollen will be used in early March when the queen starts to lay eggs. It will feed the larvae that grow long before foragers can again leave the hive to hunt for food. Goldenrod is, next to asters, the bees’ last major crop of the year. Some late wild aster will top off their winter larder, but after that the bees here in northern New England will have to wait almost a half year before they’ll see another flower.
It is during this intervening time, when the honeybees are confined to their hives, or nests, and the bumblebees are hibernating in torpor underground, that the kinglets, not much bigger than big bumblebee queens, are busily foraging in the spruce thickets. As far as we know, they do not rely on or use any food larder. Kinglets have never been observed to cache food. This does not, however, totally exclude the possibility that they do it. Maybe they’ve not been observed under the right circumstances. Potentially, kinglets are at least as intelligent and