Shell-skeletal remains of Gopherus agassizii collected at the 7.77 square km plot at the fenced Desert Tortoise Research Natural Area in 1985, 1989-1993, 1997-2002, and 2012.

The database on shell-skeletal remains from 1980 through 2012 was collected as part of a monograph covering the desert tortoise populations inside and outside the fenced Desert Tortoise Research Natural Area during a period of population decline. The principal objectives of the study were to compare trends in demographic and habitat data inside the protective fence with those outside the fence. Populations and habitat outside the fence were unprotected from recreational vehicle use and sheep grazing. Data for each shell-skeletal remain found on the long-term, 7.77 square kilometers plot, included carcass number, previous number as a live tortoise, date of collection, date last observed if marked; known or estimated size, and sex, amount or totality of remains (scutes and bones), estimated time since death, location in the environment, and relationship (if any) to anthropogenic impacts or non- human predators or scavengers, and causes of death.