Temperature(s) (Coiilnnicib 

 of the third order, 63 

 slowness of changes in, 63 



in sand dune habitat, 106, 106-107 



in winter, methods of adjustment 

 to, 99 



lethal effect of, 10 



marine: 

 and movements of currents, 354 

 effect of variations in on seashore 



animals, 354 

 of depth waters, 353-354 

 of surface waters, 353-354 

 thermoclines in, 353-354 



of alpine tundra and development 

 of invertebrates, 322 



of chloroplast in photosynthesis, 

 12 



of coniferous forests, 301-302 



of deserts as climatic barrier to 

 dispersal, 148-149 



of grassland and forest compared, 

 121 



of ponds, 79 



of streams, 43, 52-53 



of tropical biomes, 340 



of water, and selection of micro- 

 habitat according to, 246 



of woodland biome, 310-311 



range of in alpine tundra, 316 



regulation of by bees, 174-175 



relation of to reproduction of 

 CISCO, 76-77 



seasonal, and adjustments to 

 terrestrial habitats, 101-102 



snow as insulating factor in, 240 



soil, moderation of by humus, 165 



soil, of arctic tundra, 315-316 



success in competition dependent 

 on between flatworms, 252 



terms used to indicate range of 

 tolerance to, 11-12 



terrestrial, necessity of organ- 

 isms to adjust to, 98 



variation in effects of on organism 

 at different times and condi- 

 tions, 10 



vertical gradient in of deciduous 

 forests, 122, 122-123 

 Territories (stt? also Birds): 



advertisement of through sounds, 

 299 



benefits to animal of maintaining, 

 186 



control of populations in, 231 



decrease in size of and competi- 

 tion, 221-222 



defense of by simple advertisement 

 of possession, 185 



defined. 184 



differences of from "areas," 

 184-185 



Territories (Coidniiicd) 

 direct competition in defense of, 



182-183 

 establishment of best developed 



in birds, 184-185 

 high population densities in and 



lowered fecundity, 223 

 home range in, defined. 184 

 home ranges in, as providers of 



breeding locations, 186 

 increase in number of birds in, 



and effects of competition, 



221-222 

 procedures for determining home 



range in, 185 

 proclaiming of by non-breeding bird 



populations in forests, 135 

 recognition of in nesting of birds 



as technique in animal ethology, 



6 

 removal of nesting birds from, and 



consequent re-population, 215 

 size of and space requirements of 



species, 230 

 species establishing, 184-185 

 Tertiary Era: 

 appearance of deserts during, 334 

 area of growth of Arcto- tertiary 



flora during, 282 

 as period of evolution of tundra 



fauna, 318 

 boreal units of Arcto- tertiary 



flora in, 283 

 changes in forests of, 282 

 coast ranges during, 281 

 contact of Asiatic deciduous 



forest with North America 



during, 299 

 dispersal of Madro-tertiary 



flora of, 283 

 early flora of as forming modern 



vegetation types, 281-282 

 elevation of mountains during, and 



beginnings of zonation of 



vegetation, 313 

 evolution of grasslands in, 326, 



328 

 geological record of plants of, 281- 



282 

 interior of North America during, 



280 

 movement of Arcto- tertiary flora 



after drying and cooling of 



climate in, 282 

 neotropical flora of, 282 

 origin of Madro-tertiary flora of, 



283 

 peneplanation during, 280-281 

 present fauna of Indo-West Pacific 



marine region as possibly ex- 

 pressing profusion of forms 



during, 371 



Tertiary Era (Coidiniied) 

 separation of Arcto- tertiary forest 



during into North American 



and Eurasian biociations, 307 

 separation of North American 



coniferous forest during into 



eastern and western sections, 



307-308 

 Sierra Nevada and Cascade Moun- 

 tains during, 281 

 similarity of North America floras 



and faunas as due to distribution 



of Arcto-tertiary flora of, 282 

 temperate units of Arcto-tertiary 



flora in, 282 

 Thermocline: 

 as permanent feature in mid-depths 



of temperate and subtropical 



waters, 353-354 

 defined. 61-62 

 seasonal, in sea, 353-354 

 Threshold: 

 and efficient functioning of 



organism, 10 

 and lower limit of tolerance, 10 

 and upper limit of tolerance, 10 

 defined. 10 

 Toleration: 

 climatic succession occurs as 



result of reaching limits of, 



23-24 

 of intertidal animals to exposure 



and submergence and zonation, 



362-363 

 of low oxygen and high carbon 



dioxide content in marine waters 



by burrowing animals, 365 

 of pH changes by lake organisms, 66 

 terms used to indicate extent of, 



11-12 

 variation among species in limits 



of to same factor, 11-12 

 variations in activities of species 



conditioned by stress rather 



than limits of, 11 

 variations in to temperature by 



different species, 98 

 Trapping: 

 as method in determing existence 



of home ranges of animals, 185 

 use of kill-traps in for censusing 



small mammals, 35-36 

 use of live traps in for censusing 



small mammals, 36 

 Trophic Levels [see also Energy; 



Productivity): 

 and biomass, 198-199 

 and rates of metabolism, 199 

 animals distinguished as hetero- 

 trophic in, 196 

 balanced, conditions prevailing 



during, 206-207 



Index 445 



