Reprinted from a September 3. 2006 column in the Morgantown Dominion Post
Last week I indicated that I’d report on my mountain goat bowhunt to British Columbia. But I’m late getting home from that hunt, so that will have to come next week. This week let’s look at some deer questions about the basic biology of deer. It might be fun.
Can whitetails see color?
This question has been bantered about for many years and there is some question about this. However, almost all researchers now believe that deer can see color, though not as we do. Research shows that deer do have rods and cones needed to perceive color.
Because humans have more cones, they can see three distinct hues ... reds, greens, and blues. From those three colors we see all the colors of the rainbow. Deer have more rods than cones and only see two hues ... yellows and blues. Their peak sensitivity is in the blues, dropping off in the yellow range. Deer can’t see the reds. But the added rods allow them to see very well in low light. The conclusion is that reds and oranges are seen in some form of gray color. If a deer spots you wearing orange color, it isn’t because of the orange, it is because of the big block of gray they are seeing.
The ability to see in low light is because they have a tapetum lucidum located behind the retina. This membrane reflects light back through the retina, increasing the amount of light available to the eye, enhancing night vision. When you shine a light in the eye of a deer at night, you get that reflection because deer have this tapetum. In addition, deer’s eyes are not close together as ours are. Predators tend to have eyes close together giving them better binocular vision. Deer, however, have eyes further apart, which gives them better overall vision. The added rods also give deer an extraordinary ability to detect movement. What hunters need to take away from all this is that movement is what does us in. Movement. Movement. Do not move. When on stand, do not make unnecessary movements.
How common are albino deer?
Obviously albino deer are not very common. One estimate put them at one in 10,000, but others go as high as one in 50,000. More interesting than the rarity is the reaction such deer generate in observers. Did you ever notice that deer hunters can tell you the exact date, time, and location of when they saw an albino deer? It’s true, and the sight of an albino is something truly unique. When a hunter harvests an albino, they either get’s his/her photo in the local paper, or they are ostracized by their hunting friends and hated by non hunters. In fact albino deer are so loved by hunters and non hunters alike, that in some states and some areas, it is illegal to harvest them. Are such protective measures useful? From a biological standpoint, probably not. Albinism is a recessive genetic trait, and most animals with recessive traits don’t do well in the wild. One way to look at this is to consider the fact that if white deer were caused by dominant genes, then most deer would be white. Obviously being white is not particularly useful for deer.
Then why do we have localized populations of white-tailed deer? Because we don’t have large predators (other than man) living there to eat the deer or because they are protected.. But creating laws to make albino deer off limits to hunters has nothing to do with biology and everything to do with emotions. They are pretty and people don’t want them killed. Period.
Is It Possible For Twin Fawns To Have Different Fathers?
We’ve always believed that when you saw a doe with twin fawns, they were identical twins. That is, they had one father. However in the past four years different studies used DNA tests on fawns to determine the parents. Basically it works the same as Crime Stopper on television. Wildlife researchers sample the DNA of as many does and bucks in an area, then the nest spring, they sample the DNA of as many fawns as possible. One study was done in a 5,000-acre pen in Texas, the second in the wild on a wildlife management area in Oklahoma and the third in a 1280-acre pen in Michigan.
In all three cases, between 20-25 percent of twin fawns, had different fathers. We’ve all seen a hot doe being harassed and chased by more than one buck. Anna Bess conducted the Michigan study and theorized that non-identical twin fawns were conceived in this manner. A younger buck finds a hot doe and mates her. Then a dominant older buck moves in and drives the younger guy away, and mates the doe. Bess’s data support this theory because in the six set of twins that she found with different fathers, in every case one of the fathers was 2 ½ to 5 ½ years of age, while the second buck was either 5 ½ or 6 ½ years of age.
The fact that you now know that about one-quarter of all twin fawns have different fathers won’t help your hunting success. However, it is nice to know something that the PETA folks don’t know. And, such facts increase your knowledge about deer. Aldo Leopold once said that the more we know about something, the more we appreciate it. True for deer.
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