The status and distribution of the Small Travancore Flying Squirrel (Petinomys fuscocapillus fuscocapillus) and the Large Brown Flying Squirrel (Petaurista philippensis) in the Western Ghats.

A survey of the two species of flying squirrels P. f. fuscocapillus and P. philippensis was conducted in the Western Ghats of Tamil Nadu and Kerala for a period of four months, between February 2000 and May 2000. P. f. fuscocapillus was encountered on 11 occasions and P. philippensis was encountered on 199 occasions. P. f. fuscocapillus was encountered only in Evergreen and Moist deciduous forests up to an elevation of 900m, and was encountered more in Evergreen forest (Encounter rate: 0.12 squirrels/ km 0.069 S.E., n= 25 walks) than in Moist Deciduous forest (Encounter rate: 0.03 squirrels/km 0.028, n=19 walks). P. philippensis was encountered over a broader range of habitat types and altitude and was encountered most in Moist Deciduous forests (Encounter rate: 1.60 squirrels/ km 0.655 S.E., n=19 walks), followed by Plantations (Encounter rate: 1.36 squirrels/ km 0.486 S.E., n=8 ) and Evergreen forests (Encounter rate: 1.6 squirrels/ km 0.286 S.E., n=25). Neither species was encountered in Dry Forests. The encounter rate of P. f. fuscocapillus was significantly lower than the encounter rate of P. philippensis in both Evergreen forests (Mann Whitney U test, n1=n2=25, z=-4.893,p 0.001) and Moist Deciduous forests (Mann Whitney U Test, n1=n2=19, z=-4.016, p 0.0001). The encounter rate of P. philippensis (1.33 squirrels/ km 0.726 S.E., n=18 walks) was significantly greater than the encounter rate of P. f. fuscocapillus (0.69 squirrels/ km 0.033 S.E., n=18 walks) in the elevation range 0-500 m (Mann Whitney U test, n1=n2=18, z=1.605, p<0.05). Habitat characteristics were measured at sites where flying squirrels were and were not sighted, and analysis of the variables revealed that stands where flying squirrels were found contained taller and larger trees than stands where they were not found. The height of trees in stands where P. philippensis was sighted was significantly higher than the height of trees in stands where it was not sighted (Mann Whitney U test, n1= 474, n2= 207, z=-3.50, p<0.001). The height of the tree utilised by both species of flying squirrels was also greater than the surrounding trees (P. f. fuscocapillus: Mann Whitney U Test, n1= 56, n2= 14, z = -3.25, p<0.001; P. philippensis: Mann Whitney U test, n1= 264, n2= 93, z = -9.16, p< 0.001). The height occupied by the two flying squirrels different significantly (Mann Whitney U test, n1= 18, n2= 126, z=2.152, p=0.036) and P. philippensis was encountered higher (18.86 m 0.516 S.E, n=126) on the tree than P. f. fuscocapillus (18.27 m 1.096 S.E, n=18). The girths of trees in stands where no flying squirrels were sighted (1.07 m 0.06 S.E., n=225 trees) were significantly lower than the girths of trees where they were sighted (P. philippensis: Mann Whitney U test, n1=475, n2=225, z=-5.54, p<0.001; P. f. fuscocapillus: Mann Whitney U test, n1=70, n2=225, z=-2.14, p<0.05). The girths of trees utilised by both species of flying squirrels were significantly greater than the girths of other trees in the plot (P. f. fuscocapillus: Mann Whitney U Test, n1=56, n2=14, z=-3.39, p<0.01, P. philippensis: Mann Whitney U test, n1=406, n2=10, z=-9.40, p<0.01). The distance from the tree the squirrels were sighted on to the nearest neighbour was used as a measure of the relative density of the stand. The distance to the nearest neighbour in plots centred around sightings of P. philippensis was significantly greater than in the random plots (Mann Whitney U test, n1= 45, n2=97, z=-1.96, p