Fauna
Reptile · GBIF taxon 2444453

Southern Pacific Rattlesnake

Crotalus helleri

Also known as Black Diamond Rattlesnake, Pacific Rattlesnake

Southern Pacific rattlesnakes inhabit a wide range of southwestern habitats from coastal sage scrub to high mountain pine forests. Active primarily at dawn and dusk during warm months, these pit vipers use heat-sensing facial pits to ambush small rodents and lizards along rocky outcrops and brushy trails. Populations exhibit remarkable venom variation across their range, with some individuals producing potent neurotoxins alongside typical hemotoxic compounds.

VenomousReptileCrepuscular
Southern Pacific Rattlesnake reference
Licensed referencePhoto by: Chris Brown / Public domain · cc0
—observations
—countries
—peak records
Least ConcernConservation statusIUCN Red List categoriesLCNTVUENCREWEXLeast ConcernRed List categories, explained →
Key facts
Diet & prey
  • California Ground Squirrel
  • Mice
  • Western Fence Lizard
Predators
  • California Kingsnake
  • Red-tailed Hawk
  • Coyote
ThreatsHabitat fragmentation, road mortality, deliberate human persecution
HabitatsCoastal sage scrub, chaparral, oak woodlands, grassland, rocky slopes
Life span15–20 years
Classification
  1. FamilyViperidae
  2. GenusCrotalus
  3. SpeciesCrotalus helleri
Range & activity
Range data is not available yet.
Safe observation
Interaction riskVery high
  1. Low
  2. Moderate
  3. High
  4. Very high
Why interaction risk is very high
Venomous pit viper; maintain at least three meters distance and watch your footing on brushy trails.
Why it is dangerous
Delivers a potent mix of neurotoxins and hemotoxins that causes severe tissue breakdown, systemic pain, and potential respiratory distress.
How to recognize a risky encounter
Identified by a distinct triangular head, dark hexagonal dorsal pattern, and a tail ending in a segmented rattle.
What to do
Freeze and back away slowly if encountered, leaving a clear escape path for the snake.
Responsible observation
  • Watch Foot Placement: Scan trail edges, rock piles, and dense brush before stepping or placing hands.
  • Keep Distance: Back away slowly if you hear a rattle or spot a snake, maintaining at least three meters.
  • Leash Pets: Keep dogs on short leashes to prevent curious pets from approaching hidden snakes.
Related species
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