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Where Are All The Lions? Study Shakes Concept Of Predator-Prey Ratios Jeez, these predator-prey relationships were taught in my Wildlife Population Management class 30 years ago. Don’t graduate students study the published literature any more? There shouldn’t be any surprise in any of this for a wildlife graduate student. Predator population cycles follow prey population cycles with the peaks and valleys lagging a little behind the prey cycles. There are always fewer predators than prey and no wildlife biologist I know would expect predator populations to double if the prey population doubled. Predator species just don’t reproduce at the rates that prey species typically do. Nothing new here, move along. ***************************************** Where Are All The Lions? Study Shakes Concept Of Predator-Prey Ratios A researcher studying lions in Eastern and Southern Africa found a startling relationship between the availability of prey and the numbers of big cats. Surprisingly, that relationship is echoed in numerous other species. By Eva Botkin-Kowacki, Staff writer SEPTEMBER 4, 2015 Why aren’t there more lions? That question fueled a science-shaking discovery about predator-prey ratios. Double the prey does not mean double the predators, as one might expect. Instead, researchers found that an ecosystem crowded with prey held relatively fewer predators. When Ian Hatton, a McGill University PhD student, began studying lions and their prey in protected parks in East and Southern Africa, he found himself looking for more lions. A veritable feast of gazelles bounded around and Zebras trotted freely – easy pickings for a pack of hungry lions. But there were fewer than Mr. Hatton expected. Upon further research, Hatton and the other scientists discovered that this was a pattern. Prey-crowded areas had fewer lions than expected. More prey did mean a few more lions, but the lions did not increase proportionally to the gazelle population, for example. When they examined studies on other animals, the researchers saw the same pattern. Large populations of prey did not lead to a significant increase of predators. This wasn’t limited to carnivores. The same pattern appeared among herbivores and the plants they eat. “We kept being astonished,” study co-author Kevin McCann, of Guelph University’s Department of Integrated Biology, said in a news release. “This is just an amazing pattern.” Researchers surmise that this pattern emerges because of prey reproduction rates. In crowded areas, prey reproduce at slower rates. Thus the prey population is made up of many healthy adults. It’s easiest for predators to capture and kill younger prey or older, weaker prey. As such, a crowded population of prey that is reproducing at slower rates makes getting a meal more difficult for predators to find. As this predator-prey relationship suggests, every species in the food chain influences others. In ecosystems that have lost an animal, dramatic changes have been observed. Similarly, when an animal has been reintroduced to an environment, the balance has shifted for all living things. Those changes can affect many beings down the food chain. For example, when wolves were returned to Yellowstone National Park, more berries grew that bears could eat. Also, lions were re-introduced to Rwanda in June as part of a conservation effort to return the ecosystem to its natural balance. The lion population had been demolished during recovery from the 1994 genocide. In both of those cases, it was human impact that destroyed the predator population – be it wolf or lion. The case of Cecil the Lion’s death at the hands of an American dentist is just one instance of human influence, that sparked a global dialogue about humans’ role in the food chain. The pattern revealed by Hatton and the other researchers might help scientists better guide those discussions. =+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+= DRSS; NRA; Illinois State Rifle Association; Missouri Sport Shooting Association “One of the sad signs of our times is that we have demonized those who produce, subsidized those who refuse to produce, and canonized those who complain.” – Thomas Sowell, “The Vision Of The Anointed: Self-Congratulation As A Basis For Social Policy” . | ||
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so you guys should stop shooting buffalo so there will be more lions | |||
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Same with wolf in the West " Until the day breaks and the nights shadows flee away " Big ivory for my pillow and 2.5% of Neanderthal DNA flowing thru my veins. When I'm ready to go, pack a bag of gunpowder up my ass and strike a fire to my pecker, until I squeal like a boar. Yours truly , Milan The Boarkiller - World according to Milan PS I have big boar on my floor...but it ain't dead, just scared to move... Man should be happy and in good humor until the day he dies... Only fools hope to live forever “ Hávamál” | |||
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It's not the number of buffalo that affect the number of lions, it's the numbers of bloody Africans! | |||
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Amen brother!!! ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ J. Lane Easter, DVM A born Texan has instilled in his system a mind-set of no retreat or no surrender. I wish everyone the world over had the dominating spirit that motivates Texans.– Billy Clayton, Speaker of the Texas House No state commands such fierce pride and loyalty. Lesser mortals are pitied for their misfortune in not being born in Texas.— Queen Elizabeth II on her visit to Texas in May, 1991. | |||
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