552 



THE COMMUNITY 



location while asleep or at rest, and there- 

 fore, from the viewpoint of diel periodicity, 

 is the complement of the period of activity. 

 In certain cases a species may have its 

 chief period of activity during the day. 



Altitude also may affect the activity pat- 

 tern of a species population. Thus the 

 harsh-furred mouse (Lophuromys aquilus) 

 of British East Africa is usually nocturnal 

 in the lowland brush, but the portion of the 



° m"r r' n 1 1 1 1 n i 1 1 ii 1 1 n i i i 1 1 luMii 'f TT'iiiim 



16 18 20 iO 12 14 16 18 20 22 8 10 12 14 16 18 20 22 24 2 4 6 8 10 12 14 16 18 20 22 24 

 JUNE 8 JUNE 9 JUNE 10 JUNE II 



'V^> 



.^ /-'A.^,^^ 



ii V i I II 1 1 1 1 1 1 1 1 1 1 'l I' l l cf i I I II 1 1 1 I I I h ' ri i f i I ' h I l i i i lT ' fr i " i fcf i ' i fWT i n ' rVir rr i •*° 



6 8 10 12 14 16 18 20 22 24 6 8 10 12 14 16 18 20 22 24 S 10 12 14 16 18 20 22 24 6 10 12 14 16 18 20 22 



JUNE 12 JUNE 13 JUNE 14 JUNE 15 



Fig. 194. Pupation rhythm in the dung fly (Scopeuma stercoraria) . Note that the general 



frequency of the rhythm is maintained under conditions of relatively constant temperature 

 (broken line) and normal daylight fluctuation. Solid line (total of males) and dotted line 

 (total of females) show pupation peak between 0900 and 1400 hours each diel, with almost 

 no flies emerging at night between 2000 and 0600 hours. Under constant illumination or 

 constant darkness the rhythm continued, but with less pronounced peaks. (After Lewis and 

 Bletchly. ) 



but there will be a regular seasonal inter- 

 vention that alters the pattern. For ex- 

 ample, the majority of birds are diurnal, 

 but many birds, such as the warblers, 

 migrate at night; the box turtle {Terrapene 

 Carolina) also is essentially diurnal, but 

 during the period of oviposition the females 

 lay their eggs at night (Allard, 1935). 



population that inhabits the cold and foggy 

 uplands is diurnal (Roosevelt, 1910). 



Courtship and fighting patterns have 

 been correlated with the nocturnality of 

 geckos (Noble and Bradley, 1933; Evans, 

 1936), and there is a growing literature 

 upon diel rhythms of pupation in moths, 

 flies, and hymenopterans (Barnes, 1930; 



