AN infectious parasite spread by cats could almost double their owner’s possibilities of developing brain cancer, research suggests.
The scientists, led by Frederic Thomas, from the CNRS research institute in Montpellier, France, wrote in the Royal Society journal Biology Letters: “We feel our results are sufficiently strong to propose that T. gondii potentially increases the risk of brain cancer in humans.”
Often it causes no symptoms, but the parasite can be fatal to unborn babies and damage the nervous systems of people with weak immune systems.
Previous research had linked the parasite to brain tumours in animals, and there is evidence that T. gondii has effects on the brain leading to behavioural changes.
Infected rats are known to lose their fear of cats, making them more likely to be eaten. The parasite reproduces inside the intestines of cats and the organism’s egg-like oocysts are shed in cat faeces which may then contaminate food or infect other animals.
Some studies have suggested that T. gondii can alter the behaviour of humans too, making men more aggressive and even causing women to cheat on their husbands.
Parrots learn ‘name’ from parents
Parrots learn to caw their ‘names’ from their parents, according to a new Cornell study. The research offers the first evidence that parrots learn their unique signature calls from their parents and shows that vocal signalling in wild parrots is a socially acquired rather than a genetically wired trait.
Previous research had shown that wild parrots use unique ‘contact calls’ that not only distinguish each bird individually, but also communicate their gender and the mate and larger group they belong to.
Karl Berg, a doctoral student in the Department of Neurobiology and Behavior in Cornell’s College of Agriculture and Life Sciences, led the research team which set out to discover whether the contact calls of wild parrots are something they learn from their parents in their early formative weeks or whether they are genetically determined in each nestling and then taught to their parrot family and community.
The results indicated that the parents gave the chicks their own call, which the chicks chirped back at the parents and would continue to use though with some tweaking.
Berg noted that parrots have two noteworthy characteristics: a large brain relative to their body mass, and a lengthy nesting time during which nestlings are dependent on their parents.