Thursday, August 2, 2007

More Summer

Nature Watch
August 2, 2007

By Sue Benson,
CNHM Director of Education

Did you know that the first known written phenology records date back to 974 B.C. in China, or that the Japanese have records of the peak cherry blooms for the past 1,200 years? Phenology continues to provide joy to many people as they study the life cycles of plants and animals as they respond to seasonal changes.
Looking out towards the roadsides brings a splash of beautiful colors this time of year. If it is yellow that greets the eye, it could be early goldenrod or a number of other flowers. Goldenrod typically grows from knee- to waist-high, and can be identified by small yellow flowers located in pyramid-shaped clusters at the top the leafy stems. Tansy grows 3-4 feet tall, with heavily cut leaves, and a disc of smaller flowers that look like bright yellow buttons; this plant was brought from Europe because it was used in windows to keep flies away. Common mullein is a tall yellow spike with soft, hairy leaves at the base of the stem.
Shades of lavender also flash from the roadsides, and start with the very edge of the roads with short, fuzzy, fur-like flowers called rabbit’s foot clover, named for their resemblance to rabbits’ paws. Blazing stars are slender, spike-like plants that can grow up to 5 feet tall. They have grass-like leaves and hairy stems. Wild bergamot is lavender with firecracker-looking flowers and square, grooved stems, about 3 feet high. This plant is in the mint family and is used to make tea, is noted for its fragrance, and is used as an oil.
Joe-pye weed is a member of the aster family, and has purple flowers on the head and a purple spotted stem. This plant is often found in wet meadows or shallow marshes. Another lavender flower with a short tuft of flowers is spotted knapweed, an introduced, invasive species that can quickly take over fields and roadsides with its production of over 1000 seeds per plant.
Looking into the bird world this time of year, we will often find loon chicks diving and catching food on their own. Their wings are becoming more developed as they exercise them more. Adult loons will often leave the chicks and form pre-migratory flocks in early August. Mourning doves can be working on their third clutch of eggs for the season.
How do hot summer temperatures affect our waterways? According to Senior Fisheries Biologist Frank Pratt of the Hayward DNR, the Namekagon River currently is experiencing one-third less flow than average—the lowest on record. Surface temperatures for many area lakes are running 75-79 degrees F right now. Temperature data from a USGS gauge at Leonard's Spur in Hayward shows that on 90+ air temperature days, the water is at 67-69 F in early morning hours and rises to 77-80 F in late afternoon/early evening.
When air temperatures are in the mid-70s to mid-80s the water temperature cycle is more like 59-64 F at the low end and 74-78 F at the high end. Pratt stated, “For most species except trout, cisco, whitefish, and northern pike, these temps (70-80) are good for growth and survival. That’s why we call species like musky, bass, bluegill etc. "warm-water" species. The former group would be what we call "cold-water" or "cool-water" species. They seek out cooler water (<70) href=""> to learn more about exhibits and programs.

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