Rabbits of Anza-Borrego Desert State Park
Swift Survivors of Changing Landscapes

Rabbits and hares have been an important part of North America's ecosystems for millions of years. Although they are often overlooked beside the larger mammals of Anza-Borrego Desert State Park, their fossils provide valuable evidence for reconstructing ancient environments and the evolution of modern desert communities.
As abundant herbivores and an important food source for predators, rabbits occupied a central role in the ecosystems of the Pliocene and Pleistocene.

Rabbits in Ancient Anza-Borrego
During the Pliocene and Pleistocene, the Anza-Borrego region supported grasslands, open woodlands, river valleys, and eventually expanding desert habitats. Rabbits thrived in these changing environments, feeding on grasses, shrubs, and other vegetation while serving as prey for a wide variety of carnivores.

Their remains are commonly found alongside fossils of coyotes, foxes, bobcats, saber-toothed cats, eagles, owls, snakes, and other predators, illustrating their importance in the prehistoric food web.

As climates became increasingly arid, rabbit communities adapted to the developing desert landscape.

Built for Speed and Survival
Members of the rabbit family are characterized by powerful hind legs, excellent hearing, and rapid reproduction. These adaptations allowed them to survive in habitats ranging from open grasslands to rocky desert slopes.

The fossil record documents both jackrabbits and cottontails, animals that continue to inhabit southern California today. Their long evolutionary history demonstrates the success of these adaptable herbivores across a wide range of environmental conditions.
Because rabbits are sensitive to vegetation changes, their fossils help paleontologists interpret shifts in climate and habitat through time.

Relatives of Modern Rabbits
Most fossil rabbits from Anza-Borrego belong to lineages that still occur in western North America today. This continuity allows scientists to compare ancient and modern ecosystems and better understand how animal communities responded to changing climates during the Ice Ages.

Although the species have remained relatively similar, the environments they inhabited changed dramatically as rivers, lakes, and woodlands gradually gave way to the modern Colorado Desert.

What Rabbit Fossils Tell Us
Rabbit fossils help scientists reconstruct:
  • Ancient vegetation and habitats
  • Climate and environmental change
  • Predator-prey relationships
  • Evolution of small mammals
  • The development of modern desert ecosystems
Because rabbits are both abundant and environmentally sensitive, they provide valuable evidence for understanding prehistoric ecosystems.

Explore a Fossil in 3D
Rotate, zoom, and examine this specimen from the Anza-Borrego Desert State Park collections.
Interactive 3D Model: Sylvilagus hibbardi
Specimen Information
  • Catalog Number: LACM1301 V 3479
  • Element: Skull
  • Formation: Hueso
  • Group: Palm Spring
  • Epoch: Pleistocene
  • Age: Blancan and/or Irvingtonian
  • Locality: Fish Creek / Vallecito Creek
  • Scanned using Agisoft Metashape
  • Specimen © California State Parks. 3D model produced by the Anza-Borrego Desert State Park Paleontology Society.
Why Anza-Borrego Matters
Anza-Borrego Desert State Park preserves an exceptional record of late Cenozoic mammals, including the long history of rabbits in southern California.

Together with rodents, horses, camels, mammoths, carnivores, and many other mammals, rabbit fossils help document the ecological changes that transformed the region over millions of years. Their abundance makes them one of the most important components of the park's small-mammal fossil record.

The Fossil Record
  • Cottontail (Sylvilagus)
  • Hibbard's Cottontail (Sylvilagus hibbardi)
  • Eden rabbit (Hypolagus edensis)
  • Dawson's dwarf rabbit (Pewelagus dawsonae)
  • Ancient rabbit (Hypolagus vetus)
  • Rabbit (Nekrolagus)

Quick Facts
Family: Leporidae
Includes: Cottontails and jackrabbits
Age: Pliocene and Pleistocene
Role: Small herbivores and important prey animals
Significance: Indicators of changing habitats and key members of prehistoric food webs
Location: Anza-Borrego Desert State Park, California

Learn More
Read Chapter 14, "The Small Fossil Mammals: Rodents, Rabbits and their Relatives," in Fossil Treasures of the Anza-Borrego Desert for a detailed discussion of fossil rabbits and their role in the changing ecosystems of Anza-Borrego Desert State Park.