That Crazy Wind!
If you're an avid cam watcher, you've noticed that when the wind blows beyond a gentle breeze, most of the animals disappear. Why is that anyway...whats a little wind when you're hungry or thirsty? They can't hide in the bush forever can they?
Lets look at one particular species, our ever present and abundant impalas. Beautiful creatures, but always nervous and worrying as they make there way across the open areas eating almost constantly. I guess if you were born to be prey to predators it would be a little unnerving.
Impalas, as with the majority of the antelope species, have rather large, almost pear shaped ears. It's estimated that they can hear thousands of times better than a human being. Now that's some crazy hearing! I wonder if they can hear an ant crawl under their hooves. At any rate, if you watch the ears when an impala is grazing, as he his enjoying his mouthful of grass, his ears are constantly twitching and moving independently of each other. There keen sense of hearing allows them to hear a twig snap or the tiniest growl in the deep bush. With his head down while grazing, his eyes aren't able to look all around to see what predator may be near, so the ears have taken over as a primary danger sensing tool. Sound is collected by those large ears and processed through the middle ear and eventually processed by the brain, this whole journey taking less than second. Wonder what it sounds like to have bigger ears? Take your hands and cup them around the back of your ear, following the shape of the outer ear, you will be amazed at the changed intensity of what you hear.
Well if he's got such great hearing why does the wind bother him. There in lies the disadvantage of the hearing species, including humans. When the wind is whipping around, it muffles the sounds and tricks our ears into thinking sounds are louder or softer, closer or farther, or not there at all. When the wind blows at a higher rate of speed than they are used to, the impala, relying greatly on his hearing to survive, cannot distinguish where or if there are predators waiting to pounce. So he and all his impala buddies stay in the bush in hopes they will be undetected until the wind subsides. Another sense that is hampered by the wind for our little impala is his amazing sense of smell. Often times we hear an impala alarm call in the still of the night while watching the cams. Has he seen a lion? A leopard nearby? Chances are he hasn't seen it, but has gotten a whiff of or heard the predator. If he could see it he would be completely silent and still until he thought that running would be the best alternative. Unfortunately for the impala, the predator has a keen sense of sight, that in itself being a huge advantage over the prey. Fear often triggers running, and then the chase is on. But back to the sense of smell. The ability to smell at the degree of the impalas sensory system is intriguing. Not only does his nose identify the smell, but it can tell him from which direction it is coming from, how close it is, and whether there are more than one of the threatening predators around. The ears and the nose are the impalas greatest defense against any threats. Should these senses get challenged, his speed and agility often prove to save his life. Those little twitches and jerks of fear we see him make as he tries to get a drink are merely his instinctive reactions that on most occasions keep him from being surprised by a water monitor or crocodile laying wait in the water for a thirsty mouth to break the surface of the water.
Well that's our little nature lesson for today. Now be careful and don't let people see you sitting around with your hands cupped behind your ears, they might think you are more than a little strange.