Holly Sletteland - Contact Holly
Spring Flowers
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Spring has Sprung
by Holly Sletteland
This is the time of year when Sweet Springs is awash in bloom. By the time you read this, the Giant Coreopsis will probably have faded, but the wallflowers, poppies and phacelia should still be putting on quite a show. We even have a few tidy tips and baby blue eyes coming up from our seeding last fall. We'll be hosting a stroll through Sweet Springs at 10:00 on April 20th, if you'd like to take a look for yourself. The event is in honor of Native Plant Week, which was established last year by the state legislature to promote the conservation and appreciation of California's native plants.
But there's more to like about April than wildflowers. April is when our beloved Southwestern pond turtles (Actinemys marmorata pallida) have fully reemerged from their long hibernation. Some turtles overwinter in burrows made in leaf litter or soil, while others tend to stay in the ponds under rocks, logs, mud and submerged vegetation. They start moving about again in March and April as the weather warms.
Many people are surprised to learn that the southwestern pond turtle is the only freshwater turtle found in California. The species has long been in a state of decline (since the 1800's), and was finally listed as a species of concern in 1994. Although a number of studies have been conducted on the turtles, there are still big gaps in what we know about them. I used to be surprised by the lack of knowledge about special status species, but I've reluctantly come to accept that it is too often the case. We need more funding for wildlife biologists and the agencies they work for if we seriously want to stem the tide of declining species. Nonetheless, much is known about the pond turtle and its predicament – information we can use to help them out.
We know, for example, that they prefer aquatic habitats with a mix of places to bask in the sun and ample cover to elude predators. The ponds at Sweet Springs are, unfortunately, heavily shaded by eucalyptus trees, which makes it difficult for the turtles to find places to soak up the rays. Moreover, the trees have killed off much of the vegetation around the ponds, which makes it more difficult for the turtles to find cover. In order to improve habitat for the turtles, we need to thin the trees to let more sun through, leaving some emergent logs in place.
We also know that pond turtles don't typically breed until they are 10-14 years old (they can live as long as 50-70 years!) and that the females lay their eggs on land 300 feet or more from the water. Only 8-15% of hatchlings and juveniles typically survive. This low success rate is largely attributed to predation and the turtles could greatly benefit from improved cover around the ponds. After we create an opening in the trees, we need to replant native vegetation along the banks such as sedges, rushes, willows and the like.
We also need to keep the number of non-native predators down, like bull frogs and red slider turtles, as the turtles already have more than enough natural predators. Both frogs and turtles have been dumped at Sweet Springs on more than one occasion, despite signs urging people not to do so.
Lastly, we know that pond turtles are omnivorous, but they prefer to feed on aquatic invertebrates, such as the larvae of beetles, stoneflies, caddis flies, dragonflies and other insects. Unfortunately, the ponds at Sweet Springs are low in the dissolved oxygen these organisms need to thrive and they are not as plentiful as they should be. Much of the oxygen in the ponds is consumed during the process of decomposing debris that falls from the trees. Thinning the trees around the ponds and increasing aquatic vegetation would help increase oxygen levels and the critters that require it.
In short, improving habitat for the turtles is a big job that is going to take some time. We're working on it though! In the fall of 2009, we planted a variety of native vegetation on the east side of the ponds. Turtles have been spotted using this area for hibernation a number of times in the past and we are hoping that we can make it even more attractive to them in the future. They may use it for nesting as well. We don't know. We have another volunteer day planned for Saturday, April 12th from 9am to 12 noon to insure that this area continues to improve. We need help with weeding, watering, clearing debris and checking the irrigation system. If you like turtles, I hope you'll join us in making a better home for them!
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