During the first few weeks after birth, a baby deer that is in danger automatically drops to the ground and lies motionless in a curled position, even when a predator is almost on top of it. The baby deer has no scent, so predators that may depend on their sense of smell have difficulty finding the young deer. The mother, always close at hand, tends to circle back toward where her baby lies, to get the attention of the predator.
After a failed chase by the predator, the mother comes back to her baby. The lack of an odor made the sense of smell of no use for the predator. The answer is in the spotted pattern of the fawn. As sunlight falls between the leaves and branches of the plants in the forest, a dappled pattern of light and dark spots are spread across the ground.
Young fawns hidden in vegetation are often under twelve weeks of age. Before weaning, newborn fawns nurse about four times per day, which is one of the only events where the doe will approach the fawn to avoid attracting predators.
Newborn deer all have mottled spots on their backs, but each young yearling buck also has spots where its antlers grow. Female deer stay with their mothers for up to two years, while buck fawns leave after a year. After fawns lose their spots between three and four months of age, they have other signs that show their age. For example, six-month-old fawns tend to be playful and social. White-tail fawns wander farther from their mothers. By late summer, their spots have disappeared, and their snouts look shorter than those on adults.
They weigh about 60 or 70 pounds. As a buck fawn ages, its antler spots begin to sprout as pedicles, and their heads look flatter than young doe heads.
Bucks begin their beautiful antler growth when they are ten months old. They have thin legs until they become adult bucks, which will be at five and six years of age. Throughout adulthood, their antlers shed and regrow several times during rutting seasons. Though female fawns do not reach full maturity until three years of age, they can still breed earlier.
Female fawns can become pregnant at just six months old, and give birth around 12 months old. You can spot doe fawns because they do not have antler spots or display antler growth, and they stay with their mothers for up to two years.
If you are out on a hike in the woods and you see a single fawn resting in the leaves, you should first assume it has not been abandoned. Does nurse about four times per day, while they spend the rest of the time foraging away from their babies. If you are around the deer fawn, your human scent can attract a predator, putting the yearling in danger, especially if the fawn still has hiding spots. To determine if the doe abandoned the fawn, observe the area from a distance to see if the doe returns for feeding.
While flies tend to bother most living creatures, an ill fawn will not try to shake flies off of its body. A fawn with flies in its eyes, nose, and mouth needs medical attention. Before attempting to rescue a fawn, understand that they know how to stay hidden, even as newborns. They can make themselves seem especially small by pressing their heads toward the ground and tucking their legs under their bodies.
Researchers hypothesized that camouflage patterns of white-tailed fawns were highly heritable and that spotting patterns would accurately predict their region of origin because those patterns vary spatially and temporally.
Translation: if spot pattern is an inherited trait and that pattern helps increase survival, then a population should respond to selective pressures in the environment creating different spot patterns for different environments. The awesomeness that is evolution! So did they decode the pattern? Yes, kind of. Their data support that spot pattern is moderately to highly heritable. To blend in, spot pattern needs to match the environment. This is how a selective pressure, like predation, can affect camouflage patterns of a population.
Two of the 3 populations studied had predictable spot patterns. Meaning you could determine with some level of certainty where a fawn was born based on its spot pattern. But what about the third population?
Remember camouflage pattern needs to match the environment but what if the environment keeps changing? The Delta region where fawn spot pattern was unpredictable has experienced the largest shift in land use of the 3 regions studied.
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