94 A MONOGRAPH OF THE PHEASANTS 



twenty-eight days. I have timed two settings as exactly twenty-seven days. Several 

 years ago I compiled a table correlating the duration of incubation both with the 

 development of the chick at the time of hatching and its wild habits, and since then this 

 interesting phenomenon has been observed and recorded by others. While I shall take 

 this up more in detail elsewhere, it is pertinent to mention it here. The shortest 

 duration of embryonic life in the group of Pheasants (some twenty-one days) is found 

 among the junglefowl {Gallus) and such birds as the golden and amherst pheasants 

 (Ckrysolofihus). In the firebacks {Lophura) it rises to twenty-three days ; the chicks of 

 silver pheasants {Gennaeus) spend at least twenty-five within the shell, while tragopans 

 {Tragopan), as we have seen, vary from twenty-six to twenty-eight days. Peachicks 

 {Pavo) sometimes take a full month to hatch. In the newly hatched junglefowl chicks 

 we find the flight feathers only slightly developed, extending beyond their sheaths only 

 a very short percentage of their ultimate length. On ascending the scale of increased 

 embryonic duration, the large wing feathers become more and more developed and 

 functional at the time of hatching, until in the tragopans, impeyans, and peafowl the 

 chicks can flutter some distance upward to a perch on the very first day of their life. 

 There can be no doubt of the abnormal condition of the Temminck's Tragopan chicks, of 

 which an early keeper writes : " The young birds are not so strong as the young argus, 

 and they are not able to fly until they are four or five weeks old." St. Quintin truly 

 records that Tragopan chicks only a few weeks old can flutter from perch to perch like 

 young thrushes or robins. A Tragopan chick has the primaries so greatly developed at 

 the time of hatching, that the weight of these, dragging down the wing at first, makes 

 them fairly cover the entire back and body, extending to the very caudal down. 



We may carry this scheme of gradation farther and find it well demonstrated in 

 the comparative size of the hens and the eggs. A red junglefowl hen, for instance, 

 compared with the hen of a Tragopan, gives the following significant figures — 



Weight. Body Length. Cubic Size of Egg. 



Tragopan hen . . . . I I i 



Red Junglefowl hen . . . f f \ 



Thus we find that the junglefowl hen, while averaging three-quarters of the weight 

 and size of the Tragopan, yet lays an egg of only about one-half the cubic contents. 



We can safely assume that this gradation has its cause ; probably the more need 

 for the jungle pheasants to crouch and hide for the first few days of their life, and the 

 larger, more conspicuous species, or open-haunting birds to escape by flight. Or, 

 perhaps, the vital point at issue may be the roosting place. The tendency of the 

 Tragopan to nest in trees is of necessity associated with an early development of flight 

 in the chicks. 



Whatever the exact cause, the evolved present-day result is of intense interest, and 

 gives us a hint of the terrible complexity of the equations which Nature — amunerbittlichst 

 der Lehrers — ever sets her earthly creatures — 



Will small egg + short incubation + early flight -f- hiding ability = life or death ? 

 Does moderate size of body + large egg + long incubation + early flight = success 

 or defeat ? 



