Bird tolerance to human in rural and urban area of Kathmandu Valley, Nepal

Abstract

Growing urbanization has altered behaviors of wildlife including birds. Birds perceive human as a predator and flee away when approached towards them, and a point at which birds decide a risk of predation equals to cost of escape is called flight initiation distance (FID). The escape behavior of animals was mainly due to presence of human and these are varied among bird species according to habitat, body size, sex, flock size as well as behavior. The degree to which a species tolerates human interference is one mechanism that could explain coexistence. This study was conducted to evaluate the tolerance of bird with respect to human presence in rural and urban areas and also to identify the factors affecting their tolerance. The field work was carried in urban and rural areas of Kathmandu Valley in two seasons; winter and summer. During the field visits alert distance (AD) and FID of bird species in response to human was collected. Total 991 FIDs of 45 bird species were collected during the survey, out of which 922 FIDs from 33 species were used for analysis. Generalized Additive Model was adopted to determine the effect of habitat contrast, sex, season, feeding guild, body size, flock size, behavior, and time of day on tolerance of bird. FID was lower in urban birds than their rural conspecifics. FID was varied with feeding guild, habitat contrast and winter season. Body size has positive impact on FID while flock size has negative impact. It was found more on male birds than female, birds involved in foraging than in roosting, and at morning than at late afternoon. The findings of this study recommend using FID of large, carnivore bird species as parameter for species conservation.