First Annual Crayfish Census Seeks Volunteers for Halloween Count this October
Tuesday, October 07, 2008
In 1900, members of a recently formed group known as the Audubon Society, initiated an annual census of the bird species of North America. It was, and still is, known as the Audubon Christmas Bird Count. In the first year, 27 volunteer observers participated. The event now has in excess of 50,000 participants annually, collecting and providing bird species population data for some 2000 locations throughout the western hemisphere. This information is available for use by scientists, ornithologists, and as guidance for the Audubon Society conservation biology mission. http://www.audubon.org/Bird/cbc/ The Christmas Bird Count is the oldest and largest citizen scientist event in the world. It all began with 27 volunteer observers.
This October, many crawfish enthusiasts, will begin an annual census of the North American crayfish species found in their home states. Modeled after the annual bird census, the crayfish count will establish and follow crawfish sampling routes, within a count area consisting of a single county or parish. Count areas will include as many types of aquatic habitat and water bodies as can be visited, and collection of crawfish attempted from, in one Saturday during October. Those who are ambitious might do a second nearby county on another Saturday. Participation is invited and welcomed and as many as are interested in participating should do so, in any location, anywhere that crayfish live. The crayfish count is intended to become an annual event. Count areas that include even records from only a single driveway culvert, if collected annually over time, have great value. It only takes 27 crawfish observers to have a good first year, but many more would make for a grat first year.
Crayfish, known also as crawfish and crawdads, are freshwater crustaceans native to all continents except Africa and Antarctica. Over 600 species of crayfish exist worldwide, with over 400 species found only in North America. North America thus has the greatest crawfish species diversity of any location on the planet. And yet, many Americans, even many who are nature enthusiasts, are unaware that crawfish of more than one variety exist. Many of our native crayfish species are distributed widely with populations occurring throughout a range so large in size that it includes many states. Other crawfish species occur within a very limited range requiring very specific habitat types and conditions. Troglobitic cave crawfish that are only known from a single cave system are an example of an extremely geographically restricted habitat specialist.
gThe population status and distribution of many North American crayfish species is still poorly known,h according to Nathan Johnson, co-author of the new book Texas Crawdads, a field guide to Texas crayfish species, gand many people are unaware that there even exists more than one kind of crawfish.h Johnson will help develop and will participate in the Halloween Crawfish Count in 2008 and is committed to seeing it succeed. gIncreasing public awareness of the diversity of crayfish species found in North America will encourage greater concern for this interesting freshwater organism, which is a keystone species in the aquatic ecosystems where it occurs,h explains Johnson, and ginviting the public to participate in this important work will create a sense of ownership and responsibility towards helping protect those crayfish species which are identified as populations of concern.h
In Texas, like many other southern Atlantic and Gulf of Mexico coastal states, the life cycles of many crawfish species have evolved to match the seasonal wet and dry periods of the climate, or hydrologic cycle. Crayfish typically mate in the spring/early summer during the first peak in yearly precipitation and then burrow as the heat and drought of summer arrives. With the arrival of the autumn flooding period from September-October, crayfish emerge from their burrows into surface waters and release their young. Adult and juvenile crayfish, if populations are indeed present, may be successfully collected from most suitable freshwater aquatic habitats at this time of year. Thus, Halloween seems the most ideal holiday to claim for the annual crayfish count. Any weekend or even weekday in October is fine for collecting and counting crayfish.
When sampling a crayfish location, minimum data that should be collected includes location (GPS is excellent, but not necessary), date, species identification, numbers of crayfish collected including adult Male Forms I and II, adult Females, and juveniles. Additional notes on the habitat increases the value of the record. Where no crayfish are found to be present, or water is not at a location that exhibits evidence of previous surface water inundation, this is also notable as this situation will likely vary with precipitation amounts from year to year. Even if an apparently suitable crawfish ditch, stream or pond is found dry, observers should look for evidence of burrows or the exoskeletons of dead crayfish and make note if observed.
If you are interested in participating in the inaugural Halloween Crayfish Count of 2008 or need more information, please contact at the contact email provided. and check soon for results to be posted to www.HalloweenCrayfishCount.com
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