1270 



HORMONAL REGULATION OF BEHAVIOR 



Tinbergen, 1953) , in burrows that they make 

 in the ground (bank swallow, Petersen, 

 1955) , or in natural cavities (purple martin, 

 Allen and Nice, 1952). The pied-billed grebe 

 builds a semifloating nest on the water 

 (Glover, 1953) . The Baltimore oriole builds 

 an elaborate covered woven nest of grasses 

 (Herrick, 1911), the Florida jay a woven 

 open cup (Amadon, 1944b), the storm petrel 

 a simple scrape with a few scraps of material 

 laid in it (Davis, 1957) , the black guillemot 

 no nest at all, merely holding the egg on top 

 of the webs of its feet (Storer, 1952). Swifts 

 use their own saliva as cementing material, 

 or in some species as almost the sole build- 

 ing material (Lack, 1956a). Various species 

 of megapodes, instead of building nests, 

 build large mounds of vegetable material 

 which creates the incubation temperature 

 when it rots (Fleay, 1937; Frith, 1956b). 

 Most birds build individual nests, but some 

 species build communal nests in which sev- 

 eral birds lay (smooth-billed ani, Davis, 

 1940a) , or massive woven communal struc- 

 tures within which each pair has a separate 

 chamber (sociable weaverbird, Friedmann, 

 1930). 



Share of the sexes in building. Male and 

 female may share in nest-building, either 

 approximately equally, as in house sparrows 

 (Daanje, 1941), Florida jays (Amadon, 

 1944b), and great crested grebes (Simmons, 

 1955a), or in a A-ariety of special ways. In 

 a number of species, the male is more active 

 in nest-building at first, with the female 

 doing more of it later on (e.g., red-backed 

 shrike, Kramer, 1950; herring gull, Paludan, 

 1951; cliff swallows, Emlen, 1954; black- 

 headed gull, Ytreberg, 1956). A frequently 

 occurring special case is one in which the 

 male builds the nest, and the female merely 

 adds the lining (house wren, Kendeigh, 1941 ; 

 graceful warbler, Simmons, 1954; coot, Kor- 

 nowski, 1957) . In the green heron, the male 

 at first selects the nest site, and does all of 

 the gathering, carrying, and weaving of 

 twigs into the nest. He does not permit the 

 female to enter the nest until some time 

 after he has taken up his territory. Once he 

 has allowed her to enter the nest, however, 

 he does most of the gathering and carrying 

 of twigs, and the female does most of the 

 building (Meyerriecks, 1960) . 



The male may build the nest with little 

 or no help from the female, as in the red- 

 shank (Grosskopf, 1958), the rook (Mar- 

 shall and Coombs, 1957) , and many species 

 of weaver finches (Friedmann, 1949). In 

 the zebra finch (Morris, 1954), and the 

 bronze mannikin (both of them weaver 

 finches) (Morris, 1957), the male builds the 

 covered nest, and the female shapes the in- 

 side by sitting in it and making appropriate 

 turning movements. In most species of meg- 

 apodes, it is the males alone that construct 

 the large mounds in which the eggs are to be 

 laid (Coles, 1937, Frith, 1956b). 



An interesting variation of male nest- 

 building is one in which the male builds 

 several nests and the female selects one of 

 them as the repository of the eggs. This oc- 

 curs in several species of wrens, in which 

 the nests are built by the male before the 

 arrival of the female in the spring, and in 

 which the female may line the nest she se- 

 lects (long-billed marsh wren, Weller, 1935; 

 house wren, Kendeigh, 1941 ; European 

 wren, Armstrong, 1955). The male Carolina 

 wren builds several such nests, but when the 

 female arrives, both may build a new nest 

 for the eggs (Kendeigh, 1941 ; Nice and 

 Thomas, 1948). A similar pattern is found 

 in many waders, in which the male makes 

 several nests (mere scrapes in the sand) in 

 the presence of the female, during courtship, 

 and the female lays eggs in one of them 

 (ringed plover, Laven, 1940a; lapwing, 

 Laven, 1941). 



Building by the unassisted female is far 

 more common than building by the male 

 alone. When the nest is built entirely by the 

 female, the role of the male may vary 

 greatly. In some species, the male and fe- 

 male associate only for the purposes of 

 courtship and copulation, and nest-building 

 and rearing of the young are done elsewhere 

 entirely by the female (Gould's manakin. 

 Chapman, 1935; boat-tailed grackle, Mc- 

 Ilhenny, 1937; bower birds, Marshall, 1954; 

 blackcock and rufi", Selous, quoted by Arm- 

 strong, 1947) . When the male and female as- 

 sociate on a territory during the breeding 

 season, the role of the male may vary from 

 complete indifference to the nest-building 

 activities of the female (ovenbird, Hann, 

 1937), through merely accompanying her 



