Food (Continued) 



in pelecypod-annelid biome of 



sea, 365-366 

 in streams, 54-55 

 cycles in lakes, 74-75 

 determining if prey species is used 

 as in proportion to its abundance, 

 191-192 

 determining kind of eaten by 

 animals: 

 advantages of field observation in, 



189 

 through examination of digestive 



tract before digestion, 139 

 through examination of excretory 



matter, 189 

 through killing, disadvantages of, 



189 

 through pellet analysis, 189 

 through securing contents of crop 

 or stomach without killing 

 animal, 189 

 discrimination of chemical sub- 

 stances dissolved in, 188 

 effects of decrease in on fish, 222 

 forage ratio of: 

 defined. 191-192 

 value greater than unity in, 191- 



192 

 value less than unity in, 191-192 

 value of unity in forage ratio of, 

 191-192 

 indigestible matter in, 190-191 

 kinds of consumed by garter snakes 



and differences in niches, 247 

 measuring percentage volume of 

 each item of in organism, 189 

 non-staple or emergency, described, 



190 

 of moose in coniferous forests, 



308-309 

 palatability of: 

 and enzymes, 190 

 and hydrogen-ion concentration 

 of intestines, 190 

 pelagic deposits on sea bottom as, 



352-353 

 preferences: 

 and attractiveness of food 



substances, 188 

 as established by parental feed- 

 ing, 183 

 factors in for a given species, 

 138 

 restrictions: 

 as result of chemicals affecting 



odor or taste, 195 

 as result of structural adapta- 

 tions, 195 

 as specialized behavior, 195 

 role of in survival of fruit flies, 



224 

 salts in sea as source of, 354-356 



Food (Coiitniiicd) 

 seasonal variations in, 192 

 selection of on basis of nutritional 



needs, 190 

 size differences between related 

 species and differences in 

 habits of, 249 

 size of item of and size of animal, 



191 

 sources of for tropical rain forest 



animals, 348 

 special adaptations for digestion 



of, 188-189 

 staple, described. 190 

 summary of factors in choice of, 



139 

 supply of and carrying capacity of 



area, 222 

 use of in methods to measure 

 secondary productivity of 

 energy, 204-205 

 variations in from year to year, 192 

 vulnerability as of prey species, 



192 

 wide range in variety of eaten by 

 most species, 194-196 

 Food Chains (see also Food; Food- 

 getting): 

 criteria for describing position a 



species occupies in, 249 

 determining of by correlation of 

 food eaten by different species 

 in community, 189 

 double base of, 206 

 in alpine tundra, 322 

 in ponds, 87, 95 

 marine: 

 depths at which nitrogen is 



regenerated in, 360 

 filter- feeding mechanisms of 



organisms in, 361 

 fish in, 360-361 

 in balanoid- gastropod- thallo- 



phyte biome of sea, 364 

 in pelecypod-annelid biome of 



sea, 365-366 

 invertebrates in, 360-361, 361 

 net zooplankton in, 361 

 plankton as basic link in, 351 

 role of bacteria in, 360 

 role of upwelling water currents 



in, 361 

 sharks in, 361 

 whales in, 361 

 of five links, 195 

 of four links, 195 

 of three links, 195 

 size of and productivity yield, 207 

 Food- getting {see also Food; Food 

 Chains): 

 adaptations for: 

 of bills of birds, 188 

 of mouth parts of insects, 188 



Food- getting (Conltnued) 

 of teeth of animals, 188 

 of tongues of birds, 188 

 and formation of food web, 195 

 by carnivores, concentration on 



one species in, 192 

 by forest animals under severe 



winter conditions, 299 

 habits of fish in, 191-192 

 classification of animals according 



to behavior in, 187 

 of coniferous forest animals in 



winter, 309 

 protective devices of plants in, 192 

 protective devices of prey animals 

 in, 192-194 

 Forest(s) (see also Tropical Biomes; 

 Tundra): 

 adjustment to severe winter con- 

 ditions in: 

 by animals that overwinter, 300 

 by animals that remain active 



over winter, 299 

 through migration, 2y9-300 

 annual downward migration of 



insects of, 158-159 

 annual migration of insects into, 



158-159 

 Asiatic deciduous, biociation of, 



299 

 biociation in Eurasian boreal: 

 best development in Asia of, 307 

 birds in, 307 

 genera of plants of same as in 



North America, 307 

 mammal fauna in, 307 

 biociation in North American 

 boreal: 

 Appalachian faciation of, 303-305 

 characteristic birds in, 303-305 

 characteristic mammals in, 303 

 differentiation of bird popula- 

 tions in, 305 

 high animal populations in serai 



stages of, 306 

 lack of forest- edge in southern 



border of, 306 

 location of, 303 



overlap of with western biocia- 

 tion, 303 

 similarity of species composition 

 of to that of deciduous forests, 

 305-306 

 tundra species in, 306 

 biociation in North American 

 montane: 

 location of, 307 

 many local subspecies in, 307 

 penetration of deciduous forest- 

 edge biociation into, 307 

 penetration of species from 



chaparral into, 307 

 population of birds in, 307 



418 



Index 



