When is a mud puddle more than just a mud puddle? Well, if you ask any child, the answer is "always". But when a mud puddle created by melting snow and spring rains hangs around into the summer youíve got the making of a nursery or a home; definitely not your ordinary mud puddle!
Technically these puddles are called vernal pools and they are nurseries to many bugs, frogs and salamanders. In fact, they can be the only home an animal knows, like the fairy shrimp yet they can be deathtraps, to the lowly worm. Letís find out more about the amazing mud puddle!
Why would anything want to live in a vernal pool? If youíre little and edible then a pool without fish is heaven. Thatís right, vernal pools have no fish to eat eggs, developing tadpoles and larvae and adult frogs, salamanders and bugs. After all there isnít any natural way fish can get into a mud puddle. Itís a fascinating story of evolution and natural selection in which some critters were able to survive better if they could establish a life cycle around puddles. Bugs, frogs and salamanders go through different stages in their lifeómetamorphosisóeach stage taking advantage of different kinds of habitats. Critters like spotted salamanders, wood frogs, fairy shrimp and others have evolved an aquatic stage that transforms into some other stage that doesnít require water, all before the pool dries up.
The fairy shrimp live their entire life in the pool; all two short weeks. Not without peril, however, because all those other critters in the puddle use it for food. Nonetheless fairy shrimp moms lay eggs that form a tough waterproof shell. Those eggs wait in the litter of the dried up puddle in a sort of suspended animation for the waters next spring. Look for these 1-inch shrimp-like critters swimming around upside down in puddles.
The only time you may ever see this shy and reclusive denizen of the woods, the spotted salamander, is when itís heading to the pool. Look for a dark 5-7" lizard-like amphibian with bright yellow spots. The spotted salamander uses only vernal pools to mate and lay eggs in. The eggs hatch and the larvae complete their aquatic stage just in time to walk out in the summer to hide under rocks and leaf litter. But what is truly fascinating is that Spotted Salamanders return to the same vernal pool year after year after year. This makes for a compelling reason to protect vernal pools.
Of course there are losers in the puddle story, and that would be the earthworm. While scientist are still not unanimous on puddles and worms, it seems that the soil air pockets fill us with water which effectively forces the earthworm out for moist but not waterlogged air. Some never make it.
So head out this spring to explore the mud
puddles around your neighborhood, some may be harboring nurseries and homes
for all kinds of critters. If you want to find out more, check out The
Vernal Pond Association (VPA). The VPA works to identify certify and protect
vernal pools for the good of these critters. Check out their website at: