Wednesday, March 30, 2011

Mystery Bones

Since my walk to North Beach two days ago I’ve been doing some sleuthing. I was curious about the bones I had found and brought them to my fellow naturalists. We looked at them in awe and confusion questioning, “Bird, fish, alien species, fossil?”. We ooood and ahhhed and looked at them under our hand lenses, but no one seemed to know for certain. One friend suggested sturgeon, which lead me in the right direction. I sent my photos to the state fish biologist who was a bit perplexed and then I turned to Google. My search ended with the freshwater drum. They do exist in Lake Champlain and my esteemed fish biologist confirmed it. The strange looking bone with the holes (tooth sockets) is a plate for pharyngeal teeth that drum fish use to grind up their food (mollusks). These teeth are found deeper in the mouth cavity than typical teeth in a location similar to the roof of our mouths. The other bones are the operculum or gill cover, vertebrae and ray fins (on oak leaf).

The freshwater drum also has a special bone made of calcium carbonate and a gelatinous matrix, which is found in the inner ear. The bone, termed otolith, is a balance and gravity center for living in the aquatic world. These structures start off small and grow as the fish grows. Scientists use otoliths to age fish just as dendrologists age trees. They cut the otoliths in half and study the annual rings which indicate age, stress and also environmental pollution. The stone is a creamy white and is used in jewelry as a good luck charm. I tried to find one for myself, but I guess I’ll have to stick with my pharyngeal plate and call it good. After all, it was a great excuse to get outside and spend time with my two favorite animals.

Tuesday, March 29, 2011

Waterfront Predators


After our visit yesterday Jim rode back down to the waterfront with camera in hand and Stout on leash. I was in the Jeffords building on the UVM campus absorbing information from multiple biological studies presented by my lab students. While I am veritably happy about the novel knowledge I acquired during my hours of presentations (I am now considering becoming infected by a parasitic eukaryote that can reduce anxiety levels in humans), I am regretful I missed being at the waterfront with Jim. Curiosity about the mink led him down to the water and his trip was unusually fortuitous. He saw not only one mink, but two, and the encore of the wildlife viewing affair was an affable otter bathing, sunning and eating perch! Oh well, maybe next time.




Monday, March 28, 2011

A Walk to North Beach

Jim and I headed out to North Beach in Burlington, VT, this afternoon in search of signs. I wasn't sure exactly what I was looking for, but I needed a small adventure to take my mind off of trivial thoughts, the ones that seem to take over despite their inherent unimportance. We rode our bikes on the bike path from Perkins Pier and the asphalt was clear except for a few snowy spots close to the park. On our way I noticed a small bird's nest made of dried grass and sleeping bag stuffing, a common feature in nests along this stretch of the waterfront. It was six feet in the air fashioned in the middle of five or so terminal branches of sumac. We rode our bikes past the beach until we couldn't ride anymore as a result of the unmanageable snowpack. As tires crunched through the snow to the smooth blacktop path to the beach I heard a loud knocking and hit the brakes coming to a fast stop. I looked up and a Pileated Woodpecker flew across the air to a tree a bit further away. There were two. One stayed close to the path pecking loudly looking for food and the other flew back and forth a few times before disappearing in the horizon. Both birds were female with flaming heads bobbing turning back and forth and peck, peck, pecking. Knock! Knock! Knock!

Jim and I headed to the beach and walked north to the border of North Beach and Rock Point by a cattail wetland. We heard male Red-winged Blackbirds singing to the females who answered with their chit-chit-chit-chit-chit. We basked in the sounds of spring only to be chilled by the quiet reminder of the cool winter air on our fingertips. I explored the area while Jim threw the ball up and down the beach for our dog Stout. I saw many human, dog and bike tracks running through the sand carved out by the wetland outlet stream that flowed into the lake. I climbed a black willow and took some photographs of a miniature floodplain forest and then moved into the drier forest to look for wildlife. I was quickly surprised by a Ruffed Grouse flying dramatically in the opposite direction startled by my footsteps. I looked for some sign of its residence, but could only find small areas on the ground where leaves had been moved away in a search for an hors d'oeuvre. I remarked to Jim on the common occurrence of grouse flying away leaving you guessing where in the forest litter or shrubs it came from. No sign, just a loud flapping of the wings and jumpstart of the heart muscle. I ascended slightly toward wet ground. The flooded forest was milky white and frozen and I ran quickly to the thick ice towards the center. As I neared the western edge I ran quickly again to prevent the ice from breaking under my feet. I made it to the beach and we started walking back to our bikes. As we made our way back I discovered some unidentifiable avian bones and put them in my camera bag and snapped a few photos of the rare Champlain beach grass.
We hurried to our bikes and I told Jim to keep an eye out for the mink we saw last Thursday hoping we might get lucky. As we neared the waterfront past the skatepark near the docks I spotted the mink. There were mallards and gulls making a ruckus and the little brown mink came running across the ice trying to hide under the dock. I yelled out to Jim and fumbled for the camera. The mink ran to the edge of the ice and back until it could reach shore without swimming and ran along the rip-rap toward the dock. I felt particularly lucky this day. I had accomplished what I set out to do: forget my worries, pay attention to signs and live in the moment.