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Keeping score

Amphibian road call counts and backyard frog surveys

The loss of habitat is the most critical problem facing wild life around the world and in our own backyard. As animals are displaced by development, they lose their homes and access to food and water. When wetlands are drained, wild life, including the frogs, toads, newts and salamanders found there, is displaced. This reduces the biological diversity of regions and may contribute to the endangerment of other species. As salamanders die due to the lowering of water tables in woodlots, the ring neck snake that preys on them also dies. If fields are mowed to the very edge of ponds, frogs have no cover in which to forage and the many insects frogs feed on can no longer live there. Herons that preyed on leopard frogs are displaced because of the loss of food, the increased flying distance to find food, or the disturbance of their nesting sites.

The process of extinction is a natural event. Populations may become isolated and finally die out for genetic or disease reasons. Species have always declined to the point of extinction as habitats became altered or destroyed. Animals may adapt to the slow changes that occur over great periods of time, but cannot adapt to sudden changes in their environments. The loss or alteration of habitat is of primary concern because it not only means the loss of a few high profile species but all the species of microbes, plants and animals that were once found there.

We take some species for granted without considering just how difficult survival may be, particularly in habitats altered for the development or expansion of homes and industries. We may be well aware of unwanted insects in local marshes, but we may forget the impact spraying pesticides or draining the marsh to get rid of these insects will have on amphibian populations and other wildlife species. To present all the facts before action is taken requires an understanding of the species present, and the importance of a particular habitat for their survival. If there is only one pond in your community, then all amphibians must rely on it for reproduction and as a source of water. If it disappears, so will the frogs, toads, newts and salamanders. We do not fully understand why certain wetlands attract particular species. We can specify that new ponds be constructed to mitigate the loss of existing wetlands, but we cannot ensure that the new wetland has the same wildlife value or function of that which has been lost. It is appropriate in our modern world to learn to live with insects and wetlands.

Sometimes wild life may be all around us but difficult to find. Amphibians are considered to be cryptic species as they are secretive and prefer to hide or shelter under objects. If we are to lessen our impact on the habitats important for amphibians, we must first know and record where they occur and in what numbers. Scientists could only warn of declining amphibian populations when they knew the distribution and numbers which formerly occurred. It is only recently that amphibians and reptiles were inventoried in this way. We often hear people say they no longer hear frogs calling as often as they once did. This information, although true, is considered to be anecdotal as there are no data to support these statements. Maybe the frogs have gone. On the other hand, you may be there at the wrong time of the day or year to hear frogs which only call during a specific period in the spring. Or perhaps the spring has been cooler than usual and the frogs just haven't started to call as they usually do. Routine data collection allows us to compare numbers and range from year to year.

You can help in wetland and amphibian conservation by participating in the Amphibian Road Call Counts programme, and/or the Backyard Frog Surveys. Information on these programmes and data collection forms are included in the Appendix. These programmes are sponsored by the Ontario Field Herpetologists, Norfolk Field Naturalists, Ontario Ministry of Natural Resources and the Canadian Wildlife Service. In the Amphibian Road Call Counts programme volunteers record species of frog calls and intensity of calls along a route conforming to specific criteria. Three surveys are done each year during April, May and June. It is hoped that you will adopt this route as your own and monitor it every year, for as many years as possible. If you are unable to monitor your route in future years, a replacement will be found. The Backyard Frog Surveys involve homeowners taking three minutes a night just after dark to record species of calling frogs; intensity of calling, time, air temperature, water temperature (if possible) and weather. This survey extends from April to July. The objective is to get a daily sample of calling frogs and toads from different places across Ontario so that day to day and year to year fluctuations can be monitored.

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