This is one of a very small number of clusters of monarchs that can be found today at Natural Bridges.
According to the experts, the reason for the dramatic fall in numbers is a general loss of milkweed throughout California, a plant that is required for the breeding of monarchs.
Now, as the population of monarchs that "overwinter" from late October through early March falls to dangerously low numbers, there is hope in the form of organized efforts to increase the amount of milkweed that is grown in California and elsewhere.
The illustration shows the emergence of a butterfly from its chrysalis form, and prior to that, its caterpillar form.
"Egg-laden females journey north in spring, stopping to deposit eggs on milkweed plants. In a few days, the caterpillar eats its way out of the egg casing and feeds on the milkweed. It sheds its striped outer skin multiple times as it grows, and eventually the skin hardens into a hanging shell-like chrysalis from which the adult butterfly emerges."