Birds feeding on meat, insects or carrion gulp down without caring on what they are swallowing. Therefore, they gobble down hair, feathers, teeth, bones… Some bird species, mostly night raptors, swallow their preys whole, in one piece. Their diet is based, mainly, in small rodents like mice and shrews.
But birds cannot digest all these bones, fur and feathers. What do they do, then? Once they extracted all the nutrients from the prey, they throw these waste products out.
This indigestible “rubbish” is regurgitated as a compressed ball: a pellet, which they have to cough up.
These pellets contain great information for ornithological studies, mainly those about nocturnal raptors. Their gastric fluids are usually less aggressive than in other species, so the bones are usually found in better condition.
What information do the pellets give us?
Taking a night raptor pellet apart, for example, one from a barn owl, we could tell what the dinning menu was: mice, shrews, bird chicks… This pellet contains the skull and bones, soft coated with the fur and feathers.
These pellets are usually expelled at the same place, close to barns, stables or country abandoned houses, indicating the presence of nocturnal raptors like barn owls. Having them around home, listening to their calls, and watching their astonishing white flies in the dark night is an absolute luxury.
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