The Three Phases of Vernal Pools

  • Photo by David Rosen, Wildside Photography
    Photo by David Rosen, Wildside Photography
  • Photo by David Rosen, Wildside Photography
    Photo by David Rosen, Wildside Photography
  • Photo by David Rosen, Wildside Photography
    Photo by David Rosen, Wildside Photography
  • Photo by David Rosen, Wildside Photography
    Photo by David Rosen, Wildside Photography
  • Photo by David Rosen, Wildside Photography
    Photo by David Rosen, Wildside Photography
  • Photo by David Rosen, Wildside Photography
    Photo by David Rosen, Wildside Photography

The Three Phases of Vernal Pools

Vernal pools have three distinct phases: the wet phase, the flowering phase, and the dry phase.

The Wet Phase

In winter, vernal pools swarm with aquatic life, most smaller than a freckle. Frogs and toads come to mate and lay eggs. From November through March, species race against the clock (and their predators) to grow up, mate and lay eggs before the pools dry up.

The Flowering Phase

As the pools dry down in March, the seedlings grow, springing into bloom during April and early May. Most grow to less than six inches high. Vernal pool flowers create colorful rings, patches and ribbons of yellow, white, pink and purple.

The Dry Phase

During the hot, dry summer months, vernal pools lie brown and barren among the grasslands. Birds, mammals and insects come to the pools to feed on the seeds and bulbs of vernal pool plants. While they are there, other species feed on them.

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Healthy vernal pools don't support mosquitoes

A female Mosquito rarely lays her eggs in the clean water of a healthy vernal pool.  But when a vernal pool becomes polluted, more Mosquito larvae occur in it.

Sacramento Splash - Helping children understand and value their natural world picture
Did you know there are tigers in vernal pools?

This is an Aquatic Beetle larva, more commonly known as a "Water Tiger." It's pincers are like hypodermic needles and it uses them to suck the fluid out of its prey. Yummy!