There are feral goats on Cedros. Unlike on other islands in the region (notably Guadalupe Island), they do not seem to have had a significant impact on the island ecosystem. This would be due to the fact that Cedros is on the continental shelf close to the coast and, at least temporarily, it was connected to the mainland during the last ice age when sea levels were lower than today. Then, and as a consequence of this, there are native Cedros herbivores, such as Cedros Island mule deer which on one hand compete with the goat population for food and presumably have kept it from increasing beyond carrying capacity, and on the other hand forced the native plants to keep their defenses against herbivores, unlike plants on islands without megaherbivores which tend to lack those defenses.