Variability in gut passage time of Asian hornbills

Seed gut passage time through animals influence germination and displacement distance of seeds from parent plants. Hornbills are the largest avian seed dispersers in Asian tropical forests. In this study, we compared gut passage times for five large seeded tree species across gut passage trials, for three hornbill species. This study was conducted on six captive birds in Nagaland, India. The gut passage time of seeds for the tree species varied from 5 to 536 minutes. There was no difference in gut passage times between trials, between male and female birds and different fruit tree species for the Oriental Pied Hornbill. For the Rufous-necked Hornbill, we found differences in gut passage times across trials for Beilschmiedia assamica and Polyalthia simiarum, between individuals for Livistona jenkinsiana and across tree species, especially for the female. For the Wreathed Hornbill, we found differences in gut passage times across trials for Aglaia spectabilis and Syzygium cumini, between individuals for Beilschmiedia assamica and Livistona jenkinsiana and across tree species only for the female bird. Mean gut passage times reported here are higher than those reported previously for Asian hornbills. Context-specific variability in gut passage times highlights the need to examine the causes that result in these inconsistent patterns.