Sometimes that all-you-can-eat buffet does more harm than good. Many scavenger birds, like vultures and storks, supplement their diets by stopping off at large landfill sites and rubbish dumps.
In the past, some聽research has suggested that such sites are actually helping protect some species from starvation. But a new study looking at the health of these birds suggests that they may be paying heavy price for those easy calories.
杏吧原创s at the and colleagues studied the effects of rubbish dumps on the health of one such scavenger bird, .
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They took blood samples from 48 adult black vultures who ate from a rubbish dump in Patagonia and 46 adult black vultures from the Patagonian steppe whose source of food was in the wild.
The vultures that ate at the dump were not only heavier, their blood also showed higher levels of uric acid caused by eating too much protein and excessive sugar levels due to the processed carbohydrates such as sweets and cereals they had consumed. In the long term, these levels could lead to kidney and metabolic diseases, says Plaza. They also had a heightened immune response, perhaps in relation to higher levels of pathogens at the dump.聽 More of the wild birds were found to be dehydrated, however.
The finding suggests that other bird species that regularly feed at rubbish dumps, such as the critically-endangered California condor in the US, might also be affected.
鈥淚t has been comforting to assume that these dumps are a life-line for these birds, replacing dwindling natural resources with those provided by human food waste,鈥� says Graham Martin at the University of Birmingham, UK.
鈥淭his study adds to a growing body of knowledge that feeding on dumped waste is not good news for many species. Now we can see that the health of important, and in some cases endangered, bird species may actually be threatened by the foods that we discard and accumulate in dumps.鈥�
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