Kunming Institute of Zoology, Chinese Academy of Sciences
Abstract
The characteristics and behaviours of F1f (the female hybrid of
Trachypithecus leucocephalus and T. francoisi) and its backcross
offspring (Be1, Be2, Be3 and Be4) were extensively
observed. The results showed that the hybrid F1f and its offspring had
similar characteristics with T. francoisi. Besides the black hair was
an overwhelmingly dominant character, the changing of their hair
colour, the breeding behaviour of hybridized F1,and the growing
process and behaviours of the hybrid F1f offspring resembled T.
francoisi. However the feature of T. leucocephalus was nearly not
present in the hybrid F1 and its offspring, excepting that in the
development process the time for their hair colour change was longer
and during their growth there existed imprinting phenomenon of T.
leucocephalus. Therefore it can be inferred that the gene control of T.
leucocephalus only played a supporting role and T. francoisi's gene
dominated in the hybrid F1f and their offspring. The percent of weak
infants for backcross langurs reaching 50%, which was higher than that
of the general 10%-20% of T. francoisi, suggested a sign of outbreeding
depression. Based on our observation that the hybrid F1f was able to
reproduce its offspring successfully we can make a conclusion that T.
leucocephalus should be considered as a subspecies of T. francoisi
instead of an independent species