The Hanuman langur is one of the most widely distributed and morphologically variable non-human primates in South Asia. Even though it has been extensively studied, the taxonomic status of this species remains unresolved due to incongruence between various classification schemes. This incongruence, we believe, is largely due to the use of plastic morphological characters such as coat color in classification. Additionally these classification schemes were largely based on reanalysis of the same set of museum specimens. To bring greater resolution in Hanuman langur taxonomy we undertook a field survey to study variation in external morphological characters among Hanuman langurs. The primary objective of this study is to ascertain the number of morphologically recognizable units (morphotypes) of Hanuman langur in peninsular India and to compare our field observations with published classification schemes. We typed five color-independent characters for multiple adults from various populations in South India. We used the presence-absence matrix of these characters to derive the pair-wise distance between individuals and used this to construct a neighbor-joining (NJ) tree. The resulting NJ tree retrieved six distinct clusters, which we assigned to different morphotypes. These morphotypes can be identified in the field by using a combination of five diagnostic characters. We determined the approximate distributions of these morphotypes by plotting the sampling locations of each morphotype on a map using GIS software. Our field observations are largely concordant with some of the earliest classification schemes, but are incongruent with recent classification schemes. Based on these results we recommend Hill

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Phylogenetic conservatism or rapid anthropogenic habitat modifications could increase the incidences of interspecific associations of Hanuman and Nilgiri langurs (Family: Cercopithecidae, subfamily: Colobinae) in the southern Western Ghats.  Opportunistic surveys were conducted at the Silent Valley National Park, Kerala and around Devimalai Ghats, Tamil Nadu for  Tufted Grey-Nilgiri Langur association. Based on the observations from Researchers, field assistants, forest staff, and local people, the data in terms of the time of the sighting, number of individuals, phenotypes of individuals, and the time the interaction lasted, were recorded.  The study reports data on a troop of Nilgiri Langurs (N=13) around O Valley tea estate at Devimalai Ghat, Gudalur, Tamil Nadu with some hybrid looking individuals and a Tufted female Grey Langur amongst them. A total of six  and two uni-male troops of Nilgiri Langurs  and grey langurs respectively with Tufted female Grey Langurs, and aberrant coat colored infants observed at the Neelikkal section of Silent Valley National Park are also reported. The study reasonably speculates that there could be more such locations in the southern western ghats and emphasizes the need for more systematic surveys to understand  and explore the ecology, behavior, molecular, and other likely factors contributing to the conservation of vulnerable Nilgiri langur (Semnopithecus johnii) populations.