Monday, October 13, 2008

Wildlife Pond

“If you build it, frogs will find it”
May 2006

Do you enjoy the loud and raucous “konkoreeah” of the red-winged blackbird as it announces it’s suitability as a mate, the no less subdued mating calls of our diminutive tree frogs or the brilliant acrobatic flights of the territorial dragonflies? Then a wildlife pond could give you endless enjoyment and help sustain our local wildlife.
Water is one of our most basic needs and it is just as critical to most of our native wild creatures. Water not only sustains our bodies but it is a major component of the web of life. From the smallest algae-eating organisms which provide food to carnivorous insects that in turn feed fish and birds or even fat and sleek river otters, our creeks, ponds and lakes provide crucial habitat that nourish our senses as well as the biodiversity of our natural communities.
While Metchosin is blessed with a wealth of forested lands and rocky knolls abound, we have not been as gifted with wetlands. Some residents are fortunate enough to live along one of our few creeks, within the vicinity of Blinkhorn or Matheson Lake, or near a small wetland, but most of us have little more than a dripping tap or a miserly well to remind us of the delight that water can bestow.
Naturescaping your property is a concept wherein we enhance our yards to accommodate the needs of other creatures. We can supply habitat by filling a bird feeder or erecting a bat house, by planting native plants to attract birds and butterflies or by constructing a pond.
Large, small, elaborate or minimal, a pond can supply you with endless hours of interest as you watch the arrival and “settling in” of many kinds of flora and fauna. With natural water sources in short supply and competition high, it doesn’t take long for a traveling tree frog or a patrolling dragonfly to take up residence. We once created a very small pond, only about 2 x 3 ft and 18” to 24” deep. We added a few “feeder” goldfish and before we knew it we were visited by a great blue heron, who amused us immensely with it’s mime-like immobility and lightning strikes. Well worth a few fish.
However, the years have passed and we have learned that there are more “correct” ways to build ponds and supply habitat.
When considering adding a pond to your yard, you need to first consider why it is you want a pond. You can have either a fish pond or a wildlife pond but not both in the same space. Fish will eat amphibian eggs and juveniles as well as dragonfly larvae, so if you hope to attract these creatures you should not introduce fish. Of course, you can build a fish pond to attract herons, raccoons and river otters that feed on your fish! Not a bad idea either! One loud note of caution. If you have small children, you might want to consider if you can keep them away from the pond, either by fencing them in or out, until they are old enough to appreciate the dangers of water. Otherwise perhaps you could save this article and this dream until they are over the age of five.
If you have decided a wildlife pond is in your plans, then, for maximum enjoyment, place your pond close to the house so that even during a busy day you can take a moment to enjoy it’s subtleties. A small but manageable wildlife pond functions well if it is 8 ft x 5 ft and 18-24 inches deep. It is recommended to build a pond with varying depths and sloping sides so that wildlife can enter and exit (a salamander cannot climb out of a steep-sided edge). A shallow, pebbly “beach” area allows birds to safely drink and bathe. Ponds should receive at least 5 hours of sunlight a day to promote the growth of healthy pond plants and tadpoles. Heavy leaf fall can deprive the pond of oxygen, however some shade will moderate the water temperature and prevent the pond from over-heating. A shelf that is 9-12 inches deep and 12 inches wide around the edge of the pond will allow you to place plants in containers around the edge, which will probably be used by frogs as a suitable site to lay their eggs. A few stacked flat rocks on the bottom of the pond will provide cover for tadpoles in case a heron or raccoon comes visiting. Extend some logs or rocks above the surface to provide a resting place for birds, amphibians and dragonflies. If you are using city water instead of well water or fall rains to fill your pond, let the water stand a week before adding any organisms or the chlorine might prove deadly. It will naturally dissipate over one week. Some native water-loving plants include: common cattails, yellow or white marsh marigold, wild calla, the beautiful, bright pink-flowered water smartweed and our native yellow pond lily. Large paving stones around the edge of the pond can be dangerous to frogs as they will sometimes stick to hot stones and dehydrate. Native shrubs, sedges, rotting logs and rocks around the back edge will quickly naturalize the look of the pond.
To add more diversity and an added dimension, add a bog garden while you are constructing the pond. Line a shallow area next to the pond with a liner in which you have slashed a few holes. This will help supply any bog plants which sufficient moisture yet not drown them.
If your pond starts to appear cloudy, it might be suffering from too much algal growth, a result of excessive heat and sunshine and too rich conditions. Juvenile amphibians have a huge appetite for algae but you can also add a few water snails and some oxygenating plants to restore the natural balance. If you are worried about mosquitoes, dragonfly larvae (which are quite fearsome looking), have a voracious taste for mosquito larvae. Every site and book that I’ve read has recommended adding a bucket of water from an established natural pond to kick start your pond with the correct bacteria and microorganisms it needs to thrive. If you do this, please remember to NEVER transport any amphibians with the water, it is illegal and you could be introducing invasive bullfrogs or green frogs. Soon enough tree frogs and perhaps a salamander or two will find your pond, and dragonflies, during their aerial surveys, will scout out your new habitat almost before the plants are in the water.

For excellent, detailed plans and references:
Native Plants of the Coastal Garden by Pettinger and Costanzo, 2002

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