Owl, burrowing

Owls are, however, threatened by other activities of humans. They are exposed to toxic chemicals in forestry and agriculture, and this has taken a toll on some species of owls. Burrowing owls, for example, have been poisoned by exposure to the insecticide carbofuran, which is used to control epideirric populations of grasshoppers in prairie agriculture. 

Birds do not usually rely on scent for territorial marking. Some species, however, such as burrowing owls, apply odoriferous substances to their nest cavities or burrows. The functions are not well understood. Non-avian predators are thought to be the addressees, placing such marking outside the intraspecific behavior of this chapter. 

Gervais JA, Rosenberg DK, Fry DM, et al. 2000. Burrowing owls and agricultural pesticides Evaluation of residues and risks for three populations in California, USA. Environ Toxicol Chem 19(2) 337-343. 

Most carnivores, except cats, are resistant to plague infection, but animals such as domestic dogs, all rodents, and even burrowing owls may mechani-... 

Boggs DF, Kilgore DL. Ventilatory responses of the burrowing owl and bobwhite to hypercarbia and hypoxia. J Comp Physiol 1983 149 527-533. 

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