Many people have always believed that animals hunting for prey always catch the ones that are young, old or sick. For it would be difficult for those creatures to escape a predator’s hold. Till now there was no actual proof of this fact. But latest research by French scientists in Paris, France, has proved that it is true. A report on their research came out in ‘The Economist’ magazine recently. How did they do it?
The scientists studied the hunting habits of domestic cats. And they studied the health of birds that were killed by cats with those killed in accidents. They made a detailed study of one organ or part of the birds’ bodies which was an indication of its good health. That organ was the spleen.
The scientists chose the spleen because of a particular reason. Birds that are healthy have larger sized spleens than those which keep getting infections. The spleen greatly helps in strengthening the birds’ immune system or their capacity to fight disease. So from the size of the spleen the French scientists could find out if the birds killed by domestic cats were healthy or sickly.
They examined more than 500 birds from 18 different species and made very interesting discoveries. The spleens of birds killed by cats were much smaller than those killed in accidents. It means that they were not very healthy. This was true of 16 out of the 18 species they studied. By and large the spleens of birds killed in accidents were three times larger than the spleens of birds killed by domestic cats.
Also most of the birds killed by the cats were young. Of those that died in accidents, half were young and half were adult. So while it is true that the young and the sickly birds are at a greater danger of becoming a cat’s lunch or dinner, old birds are able to take care of themselves.