Measurement(s) of Populations 

 (Continued) 

 and "saturation" of area with 



traps, 35-36 

 distribution of live traps in, 36 

 nocturnal, use of traps for, 35 

 reducing boundary of contact 

 with outside area in, 35-36 

 through radioactive labelling, 



36 

 use of bait in live trapping, 36 

 value of live- trapping in, 36 

 of soil animals: 

 earth-worms, hand- sorting of, 



38-39 

 fauna on fallen logs, censusing 



of, 38 

 macrofauna, censusing of, 38 

 megafauna, censusing of, 38 

 mesofauna, censusing of, 39 

 microfauna, censusing of, 39 

 protozoans, censusing of, 39 

 use of Berlese funnel in, 39 

 use of flotation method in, 39 

 plotting of sigmoid curve in- 

 creases, 160-161 

 relative indices and absolute 



abundance in, 31 

 sample plots as method for: 

 empirical method for determining 



size of, 32 

 precision as factor in determining 



number of, 34 

 randomly located, 32 

 relation of random distribution 



to size of, 34 

 shapes of, 32 



systematic arrangement of, 32 

 variation of size of with species 

 and density, 32 

 strip censuses, 31-32 

 trapping in for determining exist- 

 ence of home ranges, 185 

 usefulness of indices of abundance 

 in, 31 

 Metabolism: 

 adjustments in with seasonal 



changes, 102 

 and biomass, 21 

 as affecting influence of species 



in a community, 20 

 calcium carbonate as essential 



in, 105 

 changes of as cause of "motiva- 

 tion," 14 

 high rate of in birds as cause of 



migration, 157-158 

 increase in and rise of body 



temperature, 98 

 measurements of and trophic 



levels, 199 

 of nitrogen and phosphorus by 

 plants, 203 



Metabolism (Continued) 

 removal of wastes of in mutualism, 



177 

 requirement of calcium for, 167 

 Microclimate: 

 and choice of microhabitats by 



ants, 245-246 

 and choice of microhabitats by 



spiders, 246 

 as factor in competition for 



particular microhabitat, 246 

 response to by animals in seeking 



cover, 248 

 Microhabitat(s) (see also Habitat(s); 



Microclimate; Niches): 

 aquatic: 

 on surface film of ponds: 

 oxygen tensions in as factor in 



choice of by fish, 246 

 segregation of species according 



to character of substratum in, 



246 

 amount of water available in and 



level of water exchanges in 



animal, 246-247 

 as setting for traps in censusing, 



35 

 carcasses of dead animals as, 125 

 characteristics of soil of and egg- 

 laying, 246 

 choice of by arctic mammals, 246 

 choice of by four species of ants 



in relation to substratum and 



microclimate, 245-246 

 choice of on bodies of small mam- 

 mals by congeneric species of 



mites and fleas, 247 

 defined, in ecology, 6 

 differentiating features of more 



easily seen by investigation of 



particular occupants, 245 

 division of by competitive species 



and reduction of competition, 



253 

 dung in grassland as, 125 

 effect of microclimate on compe- 

 tition for, 246 

 grouping in and random dispersal, 



34 

 importance of microclimate in 



choice of by spiders, 246 

 measurement of physical factors 



in as method in ecology, 1-2 

 occurrence of bioseres in, 23 

 rock as, 104-105 

 simultaneous occupation of by 



species to carrying capacity, 



253 

 stones, rotting logs and tree bark 



as, 134-135 

 vertical gradient in factors of 



from above grasses to ground, 



122 



Migration (see also Birds): 

 annual, described. 156-157 

 annual altitudinal, described, 158 

 annual altitudinal, species involved 



in, 158 

 annual latitudinal: 

 of bats, 158 

 of bison, 158 

 of insects, 158 

 of locusts, 158 

 annual local: 

 described. 158 

 of aquatic organisms, 158 

 of insects, 158-159 

 as example of intraspecific 



cooperation, 174 

 as method of adjusting to severe 



cold of arctic tundra, 320 

 as method of adjusting to severe 

 winter conditions by forest 

 animals, 299-300 

 classification of, 156 

 daily: 

 of deciduous forest insects, 159 

 of plankton, 159 

 differences of from dispersal, 156 

 latitudinal, described. 156-157 

 metamorphic: 

 of aquatic organisms, 159 

 of insects, 159 

 no definite period of in tropical 



rain forest, 348 

 of birds: 

 annual latitudinal, 156-157 

 causes for evolution of, 157-158 

 factors in timing of, 158 

 of fish between fresh and salt 



water for spawning, 368-370 

 of primitive herds of bison, 328 

 role of in developing arctic 

 tundra fauna, 318 

 Minimum, Law of the: 

 development of, 12 

 stated, 12 

 Minor Communities (see Communi- 

 ties) 

 Moisture: 

 amount of in habitat as correlated 

 with level of water exchanges 

 in animal, 246-247 

 and absolute humidity, 97 

 and relative humidity, 97 

 as causing gradients in populations, 



296 

 belief in importance of by J. A. 

 Allen for controlling distribu- 

 tion of animals, 272-273 

 different requirements of by grass- 

 land species, and division of 

 grassland into plant associations, 

 324 

 evaporation of: 

 and relative humidity, 97 



428 Index 



