iSS3.] Barrows on Birds of tkc Lozver Uruguay. 211 



but the eggs are never visible on looking in at the orifice. The 

 birds nest at about the same time as the preceding, and the eggs 

 are similar but larger. 



93. Anumbius acuticaudatus Less. Espinero (Thorn- 

 bird). — This well-known bird abounds at Concepcion, as it does 

 almost everywhere in the Argentine Republic, where there are 

 trees or bushes large enough to support its nest. The bird is not 

 larger than our Wood Thrush ( Tiirdus mustelimis) , but its nest 

 is sometimes four feet in length,- with an average diameter of two 

 feet. Probably no nest as first completed would show these di- 

 mensions, but as the same nest is used for several seasons in suc- 

 cession its size increases until it may even exceed the above 

 measurements. The bird is rather partial to thinly-wooded dis- 

 tricts, and spends more of its time on the ground than do the two 

 preceding species. Like them it builds its nest of twigs and 

 thorns, placing it either on a tree or bush, sometimes low enough 

 to be reached by the hand, sometimes at a height of twenty or 

 thirty feet. The first new nest I ever examined was built in an 

 ombu tree at Buenos Aires and measured about two and one-half 

 feet in height by fifteen inches in diameter. 



The longer diameter was vertical and the opening at the top 

 gave access to a passageway, barely large enough to admit the 

 hand, and twisting regularly in a spiral to near the bottom where 

 it enlarged somewhat to form the nest cavity. The spiral jjassage- 

 way made rather more than two complete turns between orifice 

 and nest, and in so doing passed between two branches of the tree 

 so close together as barely to allow the passage of the bird. I 

 have several times seen nests in which these passageways were 

 made to pass completely around the (small) main stems of the 

 trees on which they were built. In other nests the passageway, 

 though never straight, was by no means a spiral, and the longer 

 axis of the nest frequently becomes only slightly raised above the 

 horizontal. Sometimes several nests are joined together and all 

 occupied at the same time, but more often a new nest is to be 

 seen built against an old one, and in the latter a Swallow or other 

 bird will have built its own nest. 



Sometimes the four or five white eggs are laid on the bare, clean 

 twigs of the nest; sometimes the whole interior — passage and 

 nest cavity — is well lined with wool and other soft substances. 

 The birds suffer much from both opossums and iguanas, the for- 



