206 BULLETIN 191, UNITED STATES NATIONAL MUSEUM 



The material used is almost literally anything that strikes the fancy of the 

 birds, although the common types are composed outwardly of coarse sticks and 

 twigs for the most part. However, we have several times found them built 

 almost altogether of different kinds of wire, while at other times the ribs of 

 sheep and the smaller bones of cattle form a large percentage. One nest con- 

 tained a large jawbone, with most of the teeth intact. * ♦ * 



"A curious feature of their nest building," they say, "is that they 

 never pick up a piece of material that has fallen from the nest, even 

 though they may have to fly for miles to get more." They cite a case 

 where a pair of ravens had made a number of unsuccessful attempts to 

 build a nest on an insecure board inside of a small building, but finally 

 succeeded. "As a result the floor beneath the nest was one great mass 

 of almost every imaginable sort of material that could be found for 

 miles around, there being included dozens upon dozens of bones of many 

 kinds. In all we estimated that there must have been between twelve 

 and fifteen bushels of material, showing how pertinacious these birds 

 are when they have decided upon a site for their nest." 



The raven's nest is often filthy and unsanitary; the wool and hair 

 used for the lining are often taken from dead animals and so are highly 

 offensive to the human nostrils; and Dawson (1923) says that "as if this 

 were not enough, the sitting bird drenches the whole recklessly with 

 its own excrement, making it a veritable abode of harpies." And 

 Bendire (1895) found that "when the nest was occupied the lining was 

 always alive with fleas." 



He says further: "The American Raven becomes attached to a site 

 when once chosen, and although its eggs or young may be taken for 

 successive seasons, it will return and use the same nest from year to 

 year. I have taken three sets of eggs (evidently laid by the same bird) 

 from the same nest for successive years ; they were readily recognizable 

 by their large size and style of markings." Bowles and Decker (1930) 

 say: "Should their first set of eggs be taken another is laid, usually in 

 the same nest; and in some cases three sets have been laid in the same 

 nest, with intervals of from seventeen to twenty-two days between sets. 

 Sometimes the same number of eggs is produc.ed in each set, but often 

 the second and third sets will contain one egg less than the first. We 

 have found that one egg is deposited daily until the set is complete." 

 Bendire (1895), on the contrary, says that the eggs are laid on alternate 

 days, or even at longer intervals. 



Eggs. — ^The American raven lays from four to seven eggs to a set, 

 but five and six are the commonest numbers, and as many as eight have 

 been recorded. Mr. GrifTee (MS.) says that larger sets are laid by 

 northern birds than by those breeding farther south ; he estimates that 

 of all complete sets in northern Oregon 30 percent would have five eggs 



