While there are few hard and fast rules in the natural world, here are a some things to look for when trying to determine the sex of a lizard. As with most examples of sexual dimorphism, a lot of them have to do with males competing for both territory and mates.
https://baynature.org/article/ask-naturalist-know-lizard-male-female/
Despite signage warning that the water is a “slow death,” not a glorious turtle retirement kingdom some pet owners seem to think it is, volunteer cleaning crews regularly fish out decomposing red-eared sliders amid heaps of litter.
Like all snakes, it has a Jacobson's organ found on the roof of its mouth. The snake flicked its forked tongue out to allow for specks of scent to adhere, then routed the smell to its snake brain.
http://www.lakeconews.com/index.php/news/51458-the-living-landscape-the-pacific-gopher-snake
The California Department of Fish and Wildlife (CDFW) is seeking information relevant to a proposal to list the Foothill Yellow-legged Frog as a threatened species.
A new study released by the Monteverde Institute today has found that when selecting a mate, female frogs demonstrate a clear preference for males who know a thing or two about the cloaca.
Native to the eastern United States, bullfrogs came to California in the 1800's. When gold miners had eaten our native and now "threatened" Red-Legged Frogs to the point of near extinction, the bullfrogs were transported into the state by the government and private individuals to fill the gap.
