Vernal pools (also known as ephemeral or springtime pools) are land depressions that hold water from winter snow melts or springtime rain. In the hotter summer months, the pools will dry up until they are seasonally filled up again. Because of this, these pools do not support populations of fish and other species that need a constant water environment to survive. However, some animals evolved to live and breed in these seasonally temporary water habitats.
Fairy shrimp, a species of freshwater shrimp, are one of these magical little creatures that are able to survive in vernal pools. What makes them so magical? Fairy shrimp spends its entire life - a mere few weeks - in their temporary water habitat. Here is where they are born, bred and die.
When a vernal pool is filled in the winter and very early spring, dry, dormant shrimp eggs come alive and hatch. Later in the spring, adults can be found. At this time eggs are produced and hatched quickly, populating the pool for that season. Eggs that are laid later in the season settle down to the bottom and dry up as the pool dries up. These eggs remain dormant through the fall and winter, going through drying and freezing cycles until the pool fills once again.
Vernal pools are also vital to the survival of amphibians because they are too shallow to support fish populations that are major predators of amphibian larvae. Salamanders, lizards, frogs and spring peepers inhabit Indiana vernal pools for breeding purposes.
Holley Savanna Nature Preserve
In the middle of Newton County lies a small nature preserve found off the beaten path. Holley Savanna is a 79-acre tract acquired by The Nature Conservancy in 1989 and later transferred to NICHES Land Trust. A mix of silver maple, pin oaks, white oaks and hazelnuts with an interesting blend of flowers makes up this beautiful former savanna habitat. Though often overlooked, several vernal ponds can also be found at the preserve. Tiger salamanders, leopard/gray tree frogs and the rare slender grass make the pools their temporary home until they dry up.
No trail exists on the preserve, but hiking is allowed. Stay to the left as you enter the woods as it is easier move around the lush underbrush.
From Rensselaer, travel west on S.R. 114 to C.R. 200E. Turn right (north) and travel roughly 2.4 miles to North Star Road. Turn right (east) and travel 1.3 miles to the cemetery on the north side of the road where a designated parking area is available for visitors. The preserve is on the north side of North Star Cemetery.