Snake diversity and their morphometric parameters in a Guinea Savanna forest of Nigeria

Snakes play a crucial ecological role; however, they remain one of the least studied groups of species in Nigeria. Since the last comprehensive evaluation in 2007, no research has been conducted on snake diversity and morphometric characteristics in the study area. We assessed snake diversity and their morphometric parameters in the Guinea savanna forest of Nigeria. Ten transect strips, each measuring 2 km by 10 m, were randomly laid out across five selected ranges. A Visual Encounter Survey was conducted along each transect to observe snake abundance and diversity. Surveys were conducted both during the day (9:00-12:00 h) and at night (19:00-21:00 h). Morphometric parameters of snakes were also measured using a standard procedure. Data were analysed using descriptive statistics and ANOVA at α 0.05. Twenty-one species of snake were identified. Bitis arietans had the highest abundance at 38.0%, followed by Boaedon lineatus at 15.5%, Dendroaspis jamesoni at 8.0%, and Naja nigricollis at 7.0%. The least encountered species were Bitis gabonica, Causus lichtensteini, and Mehelya crossi, each at 1.0%. The Ibbi range had the highest diversity index (Simpson’s = 0.781 and Shannon’s = 1.667), while the Kali range showed the best evenness (0.957). Significant differences were observed in the number of ventral scales (0.023), Inter-orbital length (0.025), snout-vent length (0.004), and head width (0.009) of different snake species. Family Viperidae were shorter (43.29 ± 3.05 cm) in body length compared to Columbridae (95.50 ± 8.77 cm) and Elapidae (81.25 ± 12.67 cm). The results of this study contribute to the limited knowledge of snake diversity in Nigeria. The findings call for further research and conservation efforts to protect these species and their habitats, considering increasing environmental pressures.