1912] Miller: Pacific Coast Avian Palaeontology 



77 



The prevailing j^nditions also led to a greatly distorted 

 relation between preffaceons and non-predaceous species in point 

 of numbers. While removing a single femur of Paramyloclon 

 there were found touching it three complete skulls of Canis 

 indianensis, and even this proportion of three to one is much 

 too small to represent the facts truthfully. In a collection of 

 bird remains made by the writer the number of specimens of 

 Aquila exceeds the number representing all the non-raptorial 

 species combined, while fifty-six per cent of the species recorded 

 are predatory. 



The cessation of struggling on the part of the entrapped 

 animal did not end its services as trap bait. Some forms which 

 normally seek an active prey, e.g., Canis and Aquila, may on 

 occasion resort to carrion. A decrepit wolf or a hungry eagle 

 may not infreqently thus supply the demands of necessity. The 

 odors emanating from these pits where freshly excavated are, 

 to human nostrils, strongly suggestive of carrion. Gases exhaled 

 by animal bodies submerged in the plastic mass would accen- 

 tuate this olfactory effect to such a degree as probably to attract 

 carrion feeders. Was this influence also felt by birds? Dar- 

 win's well-known experiments on Andean condors kept in cap- 

 tivity have long been accepted as proving that the vultures do 

 not employ the olfactory sense in the perception of food. How- 

 ever, the experiences of later naturalists with Cathartes, which 

 is often caught in wolf-traps with concealed bait, leads us to 

 emphasize the fact that Darwin was experimenting with birds in 

 captivity which had been fed perhaps from early youth in more 

 or less regular fashion. We must at least concede it possible 

 that the abundant vulture remains in the asphalt are the result 

 in part of this factor of odor in attracting them to the locality. 



