Isotopic (δ¹³C and δ¹⁵N) Niche Overlap Provides Evidence of Competition Among Five Sympatric Species of Lizards from a Caribbean Atoll Available to Purchase

Stable isotope analysis has emerged as a powerful tool for studying food webs and ecological interactions. Our study aimed to compare the trophic ecology, specifically the isotopic niche (δ¹³C and δ¹⁵N), among five species of small lizards inhabiting the Banco Chinchorro Atoll. Results showed no significant differences in δ¹³C and δ¹⁵N values among the sampled species, suggesting that all species utilize similar resources and occupy a similar isotopic niche area. Given the limited food resources in the atoll, spatial niche partitioning, proposed by Pianka (1973), may be present, potentially limiting competition among species. Lizards are known to exhibit a wide range of spatial niche partitioning strategies. Further investigations are warranted to determine whether these lizards engage in interspecific interactions, such as competition or facilitation, which could shape their dietary choices and isotopic niches. Comprehensive diet analysis, habitat characterization, and environmental monitoring are needed to elucidate underlying mechanisms driving convergence of isotopic niches among these lizard species in the Mexican Caribbean atoll.