Monitoring and Managing the Harvest of Tegu Lizards in Paraguay

Abstract

Despite the ongoing worldwide trade in reptiles, monitoring and management systems are only recently being developed for exploited lizards and snakes. We studied the tegu lizard (Tupinambis spp.) management and harvest monitoring program in Paraguay as a model for commercially exploited reptile management. Tegu lizards are among the most exploited reptiles in the world, with current quotas for Paraguay and Argentina of 300,000 and 1,000,000, respectively. We analyzed demographic data obtained from harvested skins of 2 species of tegu lizards at 2 trade levels (i.e., check stations and tanneries) over an 8‐year period. There was significant annual variation in the number, size, and sex ratios of harvested tegus. Sex ratios were consistently male biased. The proportion of small skins in the harvest decreased over time, indicating compliance with the policy to ban commerce of small tegu skins. However, disparities among check stations and tanneries indicated that small skins might have been restretched by middlemen as they were bartered up the trade chain. Our results support the conclusion that tegu lizards are withstanding the harvest in Paraguay. There was no chronological trend of increased take or decreasing size that would indicate overharvest, and there were no indicators of local population decline. However, data on hunter effort are lacking, and it is important to implement a system for quantifying hunter effort and incorporate those data into harvest models. This is the first study to report long‐term data on a harvested lizard. The approach we used here can serve as a model for monitoring and management of other commercially exploited terrestrial reptiles.

A zoological catalogue of hunted reptiles in the semiarid region of Brazil

“…T. merianeae may be hunted occasionally or in directed hunting expeditions, and it can be killed using firearms and hounds, with the aid of stones and sticks, or using traps [ 11 , 12 , 68 ]. The cinegetic importance of T. merianae and other species of this genus has been recorded in various locations in Brazil [ 3 ] and in other countries [ 59 - 61 ]. In some cases, the species is considered as food taboo and it is not consumed, such as in some localities the Brazilian Atlantic Forest [ 69 , 70 ].…”

Reptiles of the municipality of Juiz de Fora, Minas Gerais state, Brazil

“…As indicated by Martins (1998), a taxonomic revision was necessary for the genus, but despite this statement, the corresponding data for revision were not published Tupinambis merianae (Figure 3h) is a large sized species of lizard very common in Juiz de Fora, that is listed as vulnerable in Appendix II of CITES because it is targeted by hunters because mainly of their skin value (Mieres & Fitzgerald 2006). This happens in the Atlantic Forest zone of the state of Minas Gerais, where it is used also as food in rural areas (Sousa, personal observation).…”

Conspecific chemical cues facilitate mate trailing by invasive Argentine black and white tegus

“…For S. merianae and other invasive terrestrial reptiles where trapping is the prevailing management tool [33,80], trapping efficiency for females could be increased by developing chemosensory lures used in concert with trapping efforts in the breeding season. An important step toward this goal would be to develop a pheromone lure capable of being readily tested under field and laboratory settings.…”