An online resource based on the award-winning nature guide

October

Ospreys Migrating

10-15-18 osprey 014

Banding birds, and the retrieval of these bands, has provided valuable information on the movement of birds. Today we also have the benefit of satellite telemetry, in which a bird carries a tracking device and its location is calculated via satellites that orbit the Earth.  The following is just a sample of what this tracking technology has revealed about the migration of Ospreys.

There are significant differences in male and female timing of migration (females leave up to a month before males), distance traveled and overwintering locations.  There is strong fidelity to overwintering sites as well as to migration flyways.  Breeding pairs of Osprey do not migrate or overwinter together, and adults do not migrate with their offspring.  Ospreys rarely migrate at night over land but inevitably migrate at night when undertaking longer (more than 12 hours) water crossings.

Subtle insights into migratory behavior can be gained by the findings of satellite telemetry, as well.  Their first flight south by juvenile Ospreys is often largely over water. A majority of juveniles migrating over the Atlantic Ocean from Massachusetts to the Bahama Islands flew as many as 1,500 miles over a period of up to 58 hours. The fact that no adults or 2nd year birds took this route over water suggests that juvenile Ospreys learn the coastal migration route during their first trip north.

Overwintering habitat preferences have also been assessed.  Of 79 Ospreys tracked by satellite, 30.4% overwintered on coasts, 50.6% overwintered on rivers, and 19% overwintered on lakes or reservoirs, with differences based on both sex and region of origin.

These few facts don’t begin to exhaust the information gathered from banding and satellite telemetry on Ospreys, much less many other species. They just serve to illustrate how modern tracking technology compliments and increases the information formerly gathered by firsthand observation and banding.

Naturally Curious is supported by donations. If you choose to contribute, you may go to https://naturallycuriouswithmaryholland.wordpress.com and click on the yellow “donate” button.

Advertisements

Yews Fruiting

10-5-18 yew_U1A0321Unlike many other conifers, Yew does not actually bear its seeds in a cone. Botanically speaking, a modified scale wraps around a single seed and forms a fleshy, red fruit called an aril. Both the seed coat as well as the foliage of Yew contain toxic alkaloids.  Birds’ digestive systems do not break down the seed coats on the seeds so they are unharmed by eating the berries, seed and all, but the human digestive tract begins to break down the seeds and toxins are released.

For hundreds of years, people used Yew alkaloids as both a method of suicide and a chemical weapon during hunting and warfare. Even sleeping beneath the shade of a Yew bush was once considered dangerous. Today paclitaxel, a plant alkaloid derived from Yews, is used as an anti-cancer chemotherapy drug (Taxol is one of its brand names).

Naturally Curious is supported by donations. If you choose to contribute, you may go to https://naturallycuriouswithmaryholland.wordpress.com and click on the yellow “donate” button.


Woolly Bears Seeking Hibernacula

10-10-18 isabella tiger moth 119

The Isabella Tiger Moth typically has two broods during the summer.  The caterpillars (Woolly Bears) in the first brood pupate and emerge as adult moths mid-summer.  The second brood overwinters as caterpillars and pupate in the spring.  The Woolly Bears we see crossing roads at this time of year are second-brood caterpillars in search of protective hibernation sites (hibernacula).

Old-timers predicted the severity of the coming winter by the relative lengths of the black and brown bands of the caterpillars when they became easy to observe in the fall – the longer the black sections and narrower the brown section, the harder a winter they were in for.  In fact, this may have had some validity, as brown hairs (setae) are added to the middle band every time the caterpillar molts. Therefore, the older the caterpillar, the wider the brown band.  If winter comes early, the caterpillar’s brown band would be relatively narrow due to the fact it didn’t have time to mature fully and develop a wider brown section before hibernating.

The adult stage of the Isabella Tiger Moth is often overlooked, due to the appeal of the larval stage.  This tan moth, with a wingspan of 1 ½ – 2 inches, has tiny black markings on its wings.  Male and female are sexually dimorphic and can be distinguished by the color of their hind wings.  Males have yellow-pale orange hind wings while the hind wings of females are rosy. (Photo:  Woolly Bear; photo inset: female Isabella Tiger Moth)

Naturally Curious is supported by donations. If you choose to contribute, you may go to https://naturallycuriouswithmaryholland.wordpress.com and click on the yellow “donate” button.


How Does Weather Affect Foliage ?

10-8-18 fall foliage2 _U1A0617Peak foliage has arrived in northern New England and will soon be evident further south.  It’s fairly common knowledge that there are three main pigments that affect fall leaf colors:  chlorophyll (green),  carotenoids (yellow) and anthocyanins (red). Both chlorophyll and carotenoids are present in leaves throughout the growing season. Most anthocyanins are produced in the autumn, in response to bright light and excess plant sugars within leaf cells.

The amount and brilliance of the colors that develop in any particular autumn season are related to weather conditions that occur before and during the time the chlorophyll in the leaves is dwindling. Temperature and moisture are the main influences.

A succession of warm, sunny days and cool, crisp but not freezing nights seems to bring about the most spectacular color displays. During these days, lots of sugars are produced in the leaf but the cool nights and the gradual closing of veins going into the leaf prevent these sugars from moving out. These conditions – lots of sugar and light – spur production of the brilliant anthocyanin pigments, which produce reds, purples, and crimson. Because carotenoids are always present in leaves, the yellow and gold colors remain fairly constant from year to year.

The amount of moisture in the soil also affects autumn colors. Like the weather, soil moisture varies greatly from year to year. The countless combinations of these two highly variable factors assure that no two autumns can be exactly alike. A late spring or a severe summer drought can delay the onset of fall color by a few weeks. A warm period during fall will also lower the intensity of autumn colors. A warm wet spring, favorable summer weather, and warm sunny fall days with cool nights should produce the most brilliant autumn colors. (U.S. Forest Service, USDA)

Naturally Curious is supported by donations. If you choose to contribute, you may go to https://naturallycuriouswithmaryholland.wordpress.com and click on the yellow “donate” button.


Stinkhorns Maturing

10-5-18 dog stinkhorn IMG_9973There are a group of fungi known as stinkhorns — aptly named, as their foul odor can be detected even by the human nose. All stinkhorns first appear as an “egg” which can be up to two inches high. When the eggs rupture, the appearance of the different species of fungi in this family (Phallaceae) can differ dramatically, but many have a phallic-like shape. At maturity, all stinkhorns produce an olive-green to olive-brown slimy substance that has a putrid smell (to humans), but is very appealing to many insects.  This slime is loaded with the fungi’s spores. Insects landing on a stinkhorn get their feet covered with the spore-laden slime while they are busy ingesting it.  Once the insects depart, the spores are dispersed far and wide.

Stinkhorns appear suddenly, and their growth can almost be observed, as they go from the egg stage to maturity with impressive speed. While these fungi are not poisonous, it is doubtful that having smelled them, anyone would desire to eat them.  (Photo:  Dog Stinkhorn aka Devil’s Dipstick, Mutinus caninus)

Naturally Curious is supported by donations. If you choose to contribute, you may go to https://naturallycuriouswithmaryholland.wordpress.com and click on the yellow “donate” button.


Grasshoppers Laying Eggs

10-3-18 grasshopper_U1A0275Being cold-blooded, a female dew-covered grasshopper, plump with eggs, basks on a cold morning in the early morning light in order to warm her muscles up enough to allow her to jump down to the ground below.  She then inserts her abdomen into the ground with the help of an egg-laying organ called an ovipositor that is shaped like a knife, and proceeds to dig down an inch or two. It is here where her eggs will spend the winter, clustered together in a protective case of hardened foam (pod) that the grasshopper secretes while laying her eggs.  While most males perish soon after mating, females have a longer life, not dying until after laying their eggs in the fall.

Naturally Curious is supported by donations. If you choose to contribute, you may go to https://naturallycuriouswithmaryholland.wordpress.com and click on the yellow “donate” button.


Trailing Arbutus Flowering!

10-30-17 trailing arbutus1 049A7260

One of the first wildflowers to burst upon the scene in April is Trailing Arbutus, Epigaea repens – a true harbinger of spring. This plant is also referred to as Mayflower and Plymouth Mayflower, as it was a welcome sight to the Pilgrims after their first winter.

It is a first for me to find this plant in flower at this time of year; I have never even heard of this occurring. The flowers are often well hidden beneath leathery, evergreen leaves, so can survive the cold temperatures in April and May, but they face much greater challenges flowering in late October. Most of their main pollinators (bumblebees) die with the first hard frost, which most of northern New England has experienced. And even if, by some stroke of luck, a lingering bumblebee did land on and pollinate a blossom, it’s very doubtful that even with our warming climate, there would be time for fruit to form and mature.  Certainly the energy used to produce fall flowers is an expense the plant can ill afford in its efforts to reproduce.   (Photo taken 10-28-17 in Hartland, VT)