Watershield is a perennial aquatic plant whose bright green, shield-shaped leaves float on the surface of shallow water in lakes and beaver ponds. Its small purple flowers bloom from June through September, with each individual flower only lasting two days. One the first day, the female flower parts (stigma, style, ovary) are mature. After receding into the water overnight, the flower re-emerges with mature male flower parts (stamens, filaments, anthers). The anthers burst open, releasing pollen to the wind, and the flower is then withdrawn below the water where the fruit develops.
The horizontal rhizomes, or stems, of Watershield, as well as the undersides of the leaves and developing buds, are covered with a thick, jelly-like slime. Botanists theorize that it may deter snails from grazing on these plants. Watershield secretes a number of chemicals that kill or inhibit growth of a wide range of bacteria, algae, and other plants.
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These stick-like insects can be found inhabiting most freshwater ponds in the Northeast. Although called water scorpions, these water bugs aren’t even closely related to scorpions. Their name comes from the fact that they superficially resemble scorpions, with their modified grasping front legs and “tails,” which act as snorkels or breathing tubes. The long,slender water scorpions in the genus Renata are also referred to as water stick insects or “needle bugs.”
Water scorpions are formidable predators, reaching up to five inches in length. The majority of their diet consists of other invertebrates, but they have been known to take tadpoles and minnows.
Water scorpions mate at this time of year — males produce chirping noises, much like a cricket, to attract females. After mating, the female lays several eggs and attaches them to aquatic vegetation.
Equality of the sexes has yet to reach some avian species. Among them is the Ruby-throated Hummingbird, the only species of hummingbird that breeds in the Northeast. After courtship and mating takes place, the male has next to no contact with his mate(s), possibly visiting them during nest construction, but he does not lift a feather to assist in raising their offspring. By herself the female selects a nest site, builds a nest (six to ten days), lays two eggs, incubates the eggs (12 – 14 days), broods them (9 days), removes their waste, or fecal sacs, for the first two days (after which the nestlings eject their droppings from the rim of the nest) and feeds them (a total of 22 – 25 days — while young are in nest, and for 4 – 7 days after they fledge). Males spend the summer feeding, preening, bathing, stretching their wings and fanning their tails, sleeping, roosting and sunbathing. Not a bad life for him; an exhausting one for her. (Thanks to Jeannie Killam and Terry Ross for photo op.)
Twisted Stalk’s (Streptopus amplexifolius ) name is very descriptive, for not only are the stems bent slightly where the leaves clasp them, but there is a 90-degree twist in the flower stalk after it emerges from the base of the leaves, causing the flowers to hang down from the stem. Earlier in the summer, delicate, greenish-white, bell-like flowers hung below these leaf axils. Those that were fertilized are currently developing into bright yellow-to-red fruit which make the plant obvious even in the moist, shady woods where it grows. Although considered edible by some, Twisted Stalk (also called Watermelon Berry) can be mistaken for poisonous species of plants so consumption is not recommended.
Dragonflies and damselflies are unique among aquatic insect larvae in that they have a greatly enlarged hinged lower lip, or labium, which they can rapidly extend outwards to capture prey. When retracted, the prehensile labium fits like a mask over the face or is folded flat beneath the insect’s head. When hunting for prey, the dragonfly larva uses its labium like a speargun. It shoots forward as far as half the larva’s body length away, and moveable hooks on the front edge grab the prey. There are no muscles at the hinge/joint, leading entomologists to believe that the labium is extended by increased blood pressure caused by abdominal muscle contraction. It unfolds at a right angle, and extends extremely rapidly, faster than most prey can react. (photo: cast skin of dragonfly larva from which adult dragonfly emerged)
For the most part, muskrats are herbivores. They consume with relish the leaves, stems and rhizomes of emergent aquatic plants such as cattails, bulrushes, sedges, horsetails, water lilies and arrowheads. Fish, frogs and invertebrates, including crayfish and clams, are also eaten to a lesser extent. Muskrats are voracious eaters (captive muskrats eat 25 – 30% of their weight daily). When their numbers are very high, muskrats can cause what is referred to as an “eat-out,” where they mow down everything in sight.
Like beavers, muskrats can close their upper lips behind their incisors in order to cut plants underwater without taking in water and choking. (photo: two young muskrats feeding on aquatic vegetation)