Got Milk?
By Lindsey Konkel

There is a hollowed-out, fallen log on the SOC campus that every student of black bear ecology visits. One winter, a female black bear and her cubs hibernated here.

The students are always surprised to hear that female black bears give birth in the middle of winter, while hibernating. I too was pretty amazed when I first found this out. Lactation can be quite a costly proposition! How does the mother bear survive through the winter nursing her cubs while she is not eating herself?

I grew up in Wisconsin, where the license plates proclaim America’s Dairyland. In my mind, images of milk are often associated with dairy products, but in the realm of animal nutrition, there is more to milk than Holsteins and milking machines.

Milk comes from cows, yes, but also from other animals – black bears, dolphins, horses, lions, and bats to name a few. In fact, all mammal mothers lactate – lactation, or milk production is a defining characteristic of mammals.

Lactation, which is unique to mammals, provides a method of transfer of nutrients from mothers to their youngsters. When mammals are born, they are quite dependent on their mothers, having not yet developed the structures necessary, such as teeth, to forage or hunt like adults of their species. Milk, composed of sugar, fat, protein, and water, gives the infant energy and helps it grow. Transfer of nutrients via milk allows for a delay in maturity, a longer growth period in which the infant stays with and learns from the mother.

Though mammals are united by the act of lactation, not all milk is the same; the composition of milk, including the amount of sugar, fat, protein, and water can vary greatly. Throughout the course of mammalian evolution, nursing strategies and milk composition have evolved to match the life-history of different mammalian species.

What does this have to do with our black bear mother and her cubs? A female black bear with nursing cubs rarely leaves the den to forage over the winter. She relies instead on stores of fat and energy that she has accumulated over the previous seasons. This poses a conflict. The female must provide enough energy-rich milk for her cubs to survive over the winter while at the same time retaining enough energy for herself, to keep her own organ systems working properly. Organs such as the brain require simple sugars like glucose to function.

Evolution’s solution is simple yet elegant. Mother bears produce high-fat milks that are low in sugar. This enables the female to retain stores of readily available simple sugars while at the same providing her cubs with energy-rich milk, enabling them to pack on the pounds. Weighing only a half a pound to a pound when they are born, bear cubs need to grow quickly in order to survive the winter. Milk is an evolved food, a compromise between what the mother can give and what the infant needs.

There are many other mammals besides bears living in the forest. Each species produces a slightly different milk that reflects its limitations and lifestyle. For example, there are many small rodents such as mice or voles living in the forest. Like black bears, these mammals tend to produce very dense, energy-rich milks, but for a different reason. Small species are limited in how much they can consume by the size of their stomachs; high-fat milk allows for the transfer of a large amount of energy in a small amount of milk.

Deer tend to fall on the opposite end of the spectrum, producing milk that is very low in fat. A fawn is rarely seen far from its mother’s side and is allowed to nurse several times a day. Because fawns grow slowly and nurse often, there is no rush for the mother to transfer large amounts of fat to the infant; the milk is dilute, containing mostly water and sugars.

Though New Jersey’s black bear and deer populations are doing quite well respectively, perhaps too well some would suggest, the study of milk composition has become an important component of many wildlife conservation projects. If the concern for a particular species is poor reproductive success or high infant mortality, then looking at milk is an obvious place to start.

Creativity Cannot be Discounted!
By
Lindsey Konkel, SOC Intern

I am standing on the barricaded road watching a group of sixth graders, new arrivals at the School of Conservation. They are on the clock – 12 minutes to complete their challenge. Standing on a fallen log, six inches off the ground, they are engaged in a lively debate about how to reverse their order on the log without anyone falling off. Their current strategy is not working - over and over again, they try to squeeze past one another, everyone remaining standing. Inevitably, before they finish, someone falls off the log.

They look to their teacher for advice, but her lips are sealed – this is a challenge for them to figure out as a group, on their own. The group becomes frustrated; they are running out of time. People start shouting to be heard. One quiet boy at the back of the line suggests they try leap-frogging over each other to cross the log; his idea falls on deaf ears. After a few more goes at the old way, the quiet boy speaks up again. “That idea will never work,” a few say. Eventually, the rest of the group persuades the nay-sayers try leap-frogging. Excitement builds as the team begins to make progress, working together toward a goal. Finally, in the last minute they are cooperating.

Most groups of students will have this experience at some point during their stay at the School of Conservation. The Action Socialization Experiences or ASEs as described, are a series of unique group challenges that stress communication and problem solving within the group. Students quickly learn that effective group communication involves speaking and listening, brainstorming and discussing. Cooperation and team building are the obvious goals of these exercises, but I have been asking myself, how else do ASEs enrich a visiting student’s environmental education experience?

I believe the answer lies in the quiet boy or girl with the seemingly eccentric idea that finally speaks up. Creative thinking is a valuable part of this exercise and benefits both the individual and the group. So often, groups will stick with the same old strategy, even though it has proven inefficient time and again. Why? Maybe it is easier, more convenient than trying to think of a new plan – we are creatures of habit after all. ASEs are valuable because they encourage students to think outside the box to solve challenges, to engage their brains! Believe it or not, thinking can actually be fun.

So what does creative problem solving have to do with the environment? There are a lot of environmental issues on the table right now: pollution, global warming, and species extinctions to name a few. When it comes to addressing these issues as a local/national/global community, we seem to procrastinate as long as possible. We keep trying to squeeze past each other on that skinny log, and we keep falling off. It will require a lot of creative thinking and problem solving on all of our parts to figure out a way for us to live sustainably in nature. Creative thinkers, let’s share our ideas, let’s communicate and work together – we are on the clock.