8 MISC. PUBLICATION 86, U.S. DEPT. OF AGRICULTURE 
B. Maturity. 
(1) Breeding—structures and habits as related to breeding; territory 
>) 
or home range; methods of procuring mates; evidence of sexual 
selection; courting antics; love songs or calls, color, behavior, 
odors as aids to mating; relations and relative numbers of the 
sexes; normal or abnormal increase, evidence of extraordinary 
reproduction; groupings or aggregations of young or old males, 
pregnant females, or others; dates of heat and copulation, asso- 
ciated habits; condition and distribution of mammae (mastology) ; 
length of period of gestation; length of suckling period; hybridi- 
zation between related species; strength and duration of mating 
and family ties; polygamy, polyandry, promiscuity, monogamy ; 
acquisit:.n of harem; relation of parents to family; details of 
habits of parents during period of dependency of young; dates and 
manner of acquisition and loss of antlers or other structures 
related to breeding. . 
(2) Nests, shelters, and other places of resort—natural resorts at dif- 
ferent seasons; shelter chambers, bowers, lairs. dens, forms, beds; 
nests, storage chambers, chambers for deposit of excrement or for 
other purposes; purpose of nests, individual nests, associated nests, 
unoccupied nests; approaches to nests, trails, burrows, tunnels, 
runways; protection of nests through closing burrows or in other 
ways in the daytime or at night; habits associated with nest 
approach; regularity of use of bedding or nesting places; earth 
packing in burrows; isolierungs, or earth plugs, their structure 
and function; extent of den expansion; temperature studies of 
burrows and nests under different climatic and other environmental 
conditions at different depths and at different times of day, season, 
and year; numbers, plan, elevation, measurements of nests and 
nest chambers; technic for excavating and mapping cCens; for 
reproduction or making casts of tunnels; measuring length and 
volume of tunnels; taking temperature of tunnels. 
(3) Structure and behavior of mammals in nonbreeding condition—struc- 
tures and habits observable in fall and winter; temperament, adap- 
tations enabling mammal to endure stress of seasons; postbreeding 
migration, dispersal of families, flocking, wandering, food getting. 
(4) Other features in structure, behavior, or relationship peculiar to 
mature adults. 
C. Old age. 
(1) Effect of old age on structure and behavior—hermits or recluses 
among mammals. 
(2) Food and shelter of the old. 
(3) Enemies, competitors, associates, means of cooperation and protec- 
tion. 
(4) Length of life; time, place, and manner of death. 
STRUCTURE AND BEHAVIOR 
A. Structure. 
(1) Form of body—proportions, contour, weight, dimensions. 
(2) Special or noteworthy developments—head, trunk, tail, limbs, hands, 
feet, Skin, hair, muscles, bones, glands, protective armor, sense 
organs, other noteworthy features. 
(3) Periodic structural changes—changes with age; periodic sexual 
changes; changes with season, molts, growths, and loss of special 
appendages or organs. 
(4) Adaptations—overdevelopment or underdevelopment of bodily parts; 
markings or coloration—concealing, disruptive, directive, warning, 
mimicking; structures formerly beneficial, now harmful. 
B. Behavior. 
(1) Disposition and temperament—individuality, gregariousness, intelli- 
gence, instinct, attitudes, strength, vitality, endurance, tenacity of 
life, courage, esthetic sense, sociability, playfulness, games, ex- 
pression of emotions, moods, curiosity, memory, property instinct. 
(2) Senses—time and degree of development; reactions to sound, light, 
odor, taste, touch, balance; devices for appealing to senses, as 
