Figure 9 in Life history of the Rio Grande leopard frog (Lithobates berlandieri) in Texas

Figure 9. Geographic variation in sexual-size dimorphism (SSD) in the Rio Grande leopard frog (Lithobates berlandieri) from Texas (USA) across latitude (a) and longitude (b). We calculated the SSD from counties that had at least two adult specimens of each sex using the Lovich and Gibbons (1992) index. Sample sizes to calculate mean snout-vent length (SVL) of males and females from each county were: Bexar (F = 36, M = 24); Brewster (F = 3, M = 2); Cameron (F = 41, M = 28); Glasscock (F = 4, M = 15); Hidalgo (F = 6, M = 7); Hudspeth (F = 2, M = 2); Irion (F = 5, M = 13); and Uvalde (F = 13, M = 17).