Fig. 2.

Simplified version of the landscape shown in Fig. 1. (A) Reptilia. (B) Mammalia. (C) Aves. (D) Amphibia. Pink shades represent high knowledge of survival and various levels of knowledge about fertility. Dark gray shades represent low or fair knowledge, and the light gray areas indicate no demographic knowledge. For the entire range of tetrapods, only 1.3% of species have high survival and fertility information, less than 0.6% have high survival but little or no fertility information, 43.3% have limited survival and fertility information, and 54.8% have no survival or fertility information.