Vulture-eating Birds, Consuming One Cow

Cow carcasses are important food for vultures whose main food is animal carcasses. In Spain, usually cow carcasses are left intact, but in Portugal it is mandatory to dispose of cow carcasses by burying or burning them directly. Please note that today, Spain is home to 90% of the vultures in Europe. In Europe, there are strict laws against leaving cattle that have died from mad cow disease. However, in Spain, there is a massive rejection of the rule. They argue that collecting, transporting and disposing of dead livestock is expensive, and that the carbon dioxide released during burning will cause pollution. Because of the refusal, the European Union Regional Council allowed that cattle killed by mad cows could be left in the fields, provided that they were located far from settlements. Meanwhile, Portugal strictly enforces these regulations. And since then, scientists have noted a "sudden drop" in visits by griffons (Gyps fulvus) and black vultures (Aegypius monachus) across the border into Portugal. Their study determined that this was most likely related to the low availability of carcasses in Portugal, not to other causes such as climate or geographical constraints.