For females, sex can be a dangerous activity in many species (and I’m not talking about social dramas experienced with humans!) For example, in some invertebrates the male will pierce the female’s abdomen and inject sperm through the wound at the female’s own detriment (in process termed hypodermic insemination) or the danger posed by a serious love bite from an over amorous shark!
Research led by Professor Matthew Gage has shown that despite the dangers of mating in some species, the promiscuity of females will increase during certain conditions, triggering them to mate with several males. Professor Gage’s team focused on the mating of the driving flour beetle (Tribolium castaneum).
Reducing the number of individuals within a controlled population artificially created an inbred population. As numbers decreased, the potential mating partners started to dwindle. In a bid to avoid fertilisation with any close relatives, female T. castaneum actively bred with as many males as possible to ensure the genetic viability of her offspring.
Perhaps unsurprisingly, the most promiscuous females produced the largest number of offspring and consequently, aided the survival of their own genes. Professor Gage proposed the females stored a pool of sperm from each individual male to screen for the least genetically similar breeding partner.
This is an incredible evolutionary solution to environmental pressures and helps to explain why females of some species are extremely promiscuous despite the costs to their own health.
By Haley Dolton
Posted by haleydolton on September 23, 2011
The grey wolf (Canus Lupis) is seen as a mysterious animal by most due to an association with folk stories. These stories make the wolf either a hero or villain clouding their reputation to the general public further. The wolf is undoubtedly a highly impressive hunter, standing 80 – 85cm shoulder height and 105 – 160cm in length and reaching running speeds up to 34 – 38mph. However, their increasing population and great hunting abilities are causing a problem in the French Alps.
Conservation practices actively encourage the restoration of depleting populations or restoring endemic species to a country. The protection of the wolf in France was necessary because they were nearly hunted to extinction in the 1930s. The control of hunting has aided their recovery so much so, that their increasing numbers are becoming a problem.
Approximately 200 wolves (20 separate packs) are currently colonised in S. France. The wolves are believed to have migrated from Italy in the mid – 1990s and are continuing to develop their ranges. This is problematic when an expanding population encounters humans inhabiting the same area, as farmers in the French Alps believe wolves are taking their sheep.
The farmers have never before had to deal with such intelligent hunters such as the wolf and as anyone who owns a dog will know, once they pick up a trick (navigating fences to get to the sheep), they do not forget how to get the reward. During this summer, a farmer with 250 sheep has had 17 ewes taken and 10 others are missing. This puts a massive strain on these farmers in terms of financial pressures of loosing stock and hiring “body guards” for the sheep at night.
Relations between wolves and local farmers are extremely strained due to the number of their sheep taken. This year roughly 600 wolf attacks have killed at least 2000 sheep. This has led to the inevitable request of the right to hunt the problem wolves. However, is it really the wolves that are killing farmer’s sheep?
As Jean-Francois Darmstaedter of a French wolf protection agency has said,
“Remember there are eight million dogs in France and 200 wolves.”
So can farmers really blame all the attacks on a species that normally does its best to avoid any interaction with humans? In addition to this, farmers receive £115 for each sheep killed by a wolf in compensation, which may lead to some farmers exaggerating the number of attacks for more money.
The wolf should be a natural part of France’s landscape and their range (which is a concern for most) in France will be limited by decreasing wooded forest areas. In addition to this, most locals and farmers support the protection of the wolf. A collaboration between the government and local famers will ultimately produce the best management plan for the wolf as both sides of the argument will need to be explored before a sustainable agreement can be reached.
Posted by haleydolton on September 9, 2011
Once again, it is the time of year for a social experiment involving a group of “interesting” individuals in a house and observing how they interact over time. What normally ensues are arguments over everything and everything, torments of the heart and playing games (whether that be mind games or running around the house as Wizard of Oz characters!)
Many people wish to take part in Big Brother every year. But would you ever want to enter the house if the other contestants were as bad mannered as some found in the animal world? Take a look at these antisocial characters and decide which house you would rather live in or be watching!
Smelliest – you are going to be sharing a small space, for a long time and sharing it with a stinker is not going to be pleasant! Many animals produce a fowl smelling odor as defense mechanism, but one of the smelliest animals has to be the striped polecat. Found in Africa (by smell, from half a mile away!) The striped polecat fires secretions from their anal glands to deter predators. In a small house where arguments can make someone feel threatened, I would not want to risk this stink bomb going off!
Dangerous – wanting to stick it out for the entire show is most of the contestants’ top priority. However, if there are others in the house willing to remove you from the competition, then your chances of succeeding are unlikely! Most people would guess lions, hippos, crocodiles or snakes kill the most people/year due to their reputations. When in fact, it is the tiny female mosquito (only 16mm long) that kills more people/year infecting them with deadly diseases such as malaria. A tiny species, but packs a mighty punch!
Promiscuous – love is in the air every year in the Big Brother house. But in the natural world, even the biggest love rat would have competition from the mouse – like marsupial, the antechinus. The female of this polygamous species will mate with multiple males during each breeding season resulting in multiple paternity of the litter. Mating can last up to 12 hours and the males put so much effort into it, they often die due to exhaustion!
Diet – housemates always argue over the shopping budget due to people having special diets or wanting luxuries. Can you imagine the colossal shopping bill if there was a Big Brother house that could cater for a blue whale? At 25 to 32m long, these mammals can eat approximately 4 tons of krill per day! I don’t think even the greediest housemate could demand this much food!
By Haley Dolton
Posted by haleydolton on September 3, 2011