Thursday, August 23, 2012

Bald-faced Hornets

This is an insect you want to know in order to avoid it.  When they're out collecting food, I can get fairly close without upsetting them, and by moving in slowly I've gotten some decent macro shots of hornets scraping the pulp of fallen pears on the ground.  Fruit juice seems to be a favorite food of adults.

Bald-faced Hornets (Vespula maculata) are related to Yellowjackets, Paper Wasps and Potter Wasps in the family Vespidae.  At a more general scale, they are in the order Hymenoptera with bees, ants, ichneumons and other wasps.  Hornets are large and black with white markings on the face, body [thorax] and tip of the tail [abdomen].  


Only the queens overwinter.  In the spring each survivor starts a small nest with one layer of cells an inch or two in diameter.  As the new workers emerge, they take over nest building and add larger tiers [layers of cells] underneath, then cover these with an outer, gray, paper-like material made from wood pulp.  The round-topped nest usually hangs from a branch, but I've also found them close to the ground in bushes.  In fact there's one next to the trail around my property and I've had to flag and "close" that section so the grandkids don't use it.  As the nest expands, it tapers toward the bottom where the entrance/exit hole is located.  Hornets are most dangerous when you are close to their nest. Unlike bees, hornets can sting repeatedly.
 
 
 
In late summer, the males emerge to mate with future queens.  As temperatures dip well below freezing in the fall, the males die along with the female workers and old queens and any immature larvae still in the nest.  Young queens spend the winter underground or in deep leaf litter.

Corrections, comments and questions are always welcome at northeastnaturalist@yahoo.com  Also you can connect through my Facebook photo page at Dave Spier (photographic naturalist) or my personal page, Dave Spier (northeast naturalist).

Sunday, August 19, 2012

Ragweed

pollen-producing male ragweed flowers on spike-like racemes
photographed with Canon MP-E 65mm 1-5x macro

       The weather segment of the local evening news sometimes gives the pollen  information for allergy sufferers. The other night I noticed that the "Tree" and "Grass" categories were absent, but "Weeds" were high, with ragweed and Artemisia (mugwort) listed as the main culprits.

        It's the peak of allergy season for ragweed victims, and according to weed ecologists, the problem is getting worse. Increased carbon dioxide in the atmosphere and warmer temperatures are producing a bumper crop and higher-than-normal pollen counts. In other words, global warming is having an immediate impact close to home. Each large ragweed plant is capable of producing a billion pollen grains over the course of its flowering period and they all travel on the wind or a breeze.

Common Ragweed is also known as bitterweed, carrot-weed, tassel-weed and hayfever-weed (probably the most appropriate of them all). Its Latin name is Ambrosia artemisiifolia. Ambrosia now refers to the mythic food of Greek gods that allowed them to live forever, but originally it meant simply "immortal." This is probably a testimonial to the tenacity of a weed that's almost impossible to irradicate, except perhaps on a temporary local basis. The second (specific) part of its scientific name indicates its relationship, both in appearance and genetics, to Artemisia, the genus of wormwoods and mugworts. They all are prolific powdery-pollen producers in the Aster (Daisy) Family. The relationship is based on technical characteristics of the flowers, even though these particular species lack showy petals because there's no need to attract insects for pollination.

Ragweed flower detail cropped from 100mm macro shot at 1.6x
[allowing for sensor-size scale] and using a flash
against natural sky background while shielding from the wind

Instead, the wind does the pollinating. The tiny bell-like flowers have green hoods covering the yellowish male stamens. On ragweed, these blossoms are lined up along the top of the stem in a spike-like raceme. (See the opening photo.) Female flowers are even less conspicuous and grow in the leaf axils where the leaves attach to the main stem. The green leaves themselves are deeply dissected and remotely fern-like.

Common Ragweed leaf photographed with 100mm macro
after creating a shadow to hide the background

During the winter, persistent ragweed seeds -- rich in oil -- are eaten by a number of resident songbirds and upland game birds.  To humans, the seeds are bitter tasting, hence the alternate name bitterweed.  In the summer, a few ragweeds may be eaten by the caterpillars of several butterfly and moth species.

Ragweed is an annual plant that grows in disturbed ground and road shoulders.  It goes through its entire life cycle in one growing season and then dies.  From the human perspective its useless if not outright obnoxious and undesirable.  From an ecological point of view, it is a native pioneer plant that colonizes bare patches of ground after some sort of disturbance, either natural or manmade.

        Ragweed's miniscule arrowhead-shaped seeds are covered with spines that cling to any passing animal brushing by the ripe plant. Eventually they drop off and a few may land in suitably dry, sunny or partly-shaded locations.

        By contrast, dandelion and thistle seeds arrive on the wind. Goldenrod seeds have smaller fuzzy "parachutes" and travel shorter distances.  The weeds stabilize the soil and reduce erosion, paving the way for shrubs to move in.  Eventually trees gain a foothold and given enough time, a forest will regenerate itself in what was once an open field.  By then the annual ragweeds and perennial goldenrods are long gone.  They lost out in the battle for sunlight.

        Goldenrods often get blamed for allergies because they flower at the same time in the same habitats as ragweeds and mugworts, but their pollen is sticky and heavier.  Goldenrods require insects for pollination, not wind.  There's more on my Goldenrod blog.

Corrections, comments and questions are always welcome at northeastnaturalist@yahoo.com  Other articles can be found on a parallel blog at http://adirondacknaturalist.blogspot.com/  More nature photos can be found at http://www.flickr.com/photos/dave_spier

A small Common Ragweed plant; they can grow much larger and more prolific of pollen!

Wednesday, August 15, 2012

Wildflower photos request

(This is not an image for the project.
See the links for actual examples.)

Wildflower photos request (pass along) - sorry, no pay

Do you like to photograph northeastern wildflowers and can accurately identify what you find?  This project is not for pro's because there is no pay, but I pass it along in case you're interested.  The company, MyNature Apps, is requesting help in creating a digital identification guide, and there is more info on their website and more examples posted in latest their blog.

Here are some of the Wildflower App photo guidelines:

1. To repeat, there's no pay for images -- just a personal credit page for each person who contributes over 25 species. This will be featured with your own write up and a photo of you -- kind of a "meet the photographer" page. Your name will also be listed on a seperate credits page with a list of species you contributed. Your name or copyright should not appear on the image.

2. All wildflowers of the Northeast and East based on Newcomb's Wildflower Guide (plus any regional species not in the guide) are needed, but please check the current master list of species already "collected" (and updated weekly) to avoid duplication. The final goal involves roughly 1200 species, of which approximately 260 species have been photographed (as of 8/14/12).

3. Submit a complete set of vertical images at one time, i.e. no partial sets. (Otherwise, it's a logistical nightmare.) What's needed for each species are the following: the species' leaf (closeup), flower head (closeup) and whole-plant profile. (The whole-plant profile is an image of the entire plant from ground level up to the tip.) Multiple images of leaves are needed if they vary. For compound leaves include the whole leaf plus a separate image of a leaflet. For species with racemes, spikes, panicles, cymes, umbels, corymbs, and whorls, include images of the whole flower cluster plus images of an individual flower in that cluster. You can have as many images as you want for each plant feature. If there are 5 different leaf configurations on one plant you can have an image of each. Likewise you can show a front view of a flower, a side view... whatever makes the ID process easier. You don't have to be a master photographer but fairly decent.  Seedheads and fruit are not important, but it's okay if a seed pod/head or fruit can be included in an image of the leaf or flower head.  The main objective is to feature the flower and leaf as clearly and large as possible. The leaf is usually the main key in ID'ing. Think of it from the perspective of the end user who may have little (or no) experience with plants; they just want to know what they found.

4. All shots are vertical at a ratio of 2:3 (w:h) and resolution of 8"x12" @ 72 dpi [i.e., 576 x 864 pixels].

5. Diffuse/cloudy lighting is generally best for showing a lot of detail without harsh contrast and shadows in the wrong place.

6. Examples are posted at: http://www.mynatureapps.com/2012/08/specie-images/ with basic information at http://www.mynatureapps.com/2012/07/help-wanted-wildflower-photographers/

I may be able to answer a few questions or pass them along.  Please, serious inquiries only.  There is contact info on the websites, or you can email me first at northeastnaturalist@yahoo.com

Tuesday, August 14, 2012

Picris hieracioides


This is an invasive, alien weed and I generally pull it out when I have time. It resembles a tall, multi-headed dandelion with rough-hairy, almost bristly, stems and leaves. Indeed it is a relative and like dandelions, comes from a foreign land. This one is native to the mountains in southern Spain and northern Portugal. In addition to growing in my yard, I find it proliferating along roadsides, often intermingled with its close relative, blue Chicory. The combination is colorfully attractive. All these plants are in the Aster (Daisy) family and generally considered invasive weeds.

I learned it's name as "Hawkweed Picris" from a botany professor, but the rest of the world now seems to call it "Hawkweed Oxtongue." Sorry, that just doesn't have the same ring (or is it just habit)?  The scientific name is Picris hieracioides. The genus name (Picris) comes from a Greek word for bitter, referring to the plant's roots. Members of this genus are called "oxtongues." The species name indicates its close resemblance to hawkweeds, genus Hieracium.



We've described the flowers as dandelion-like, but look closely and notice that the tip of each yellow ray has five "teeth." With age, the blossom becomes a fuzzy seed head. Without adequate sunlight, though, the plant never reaches the flowering stage and remains a basal rosette of leaves (on the ground).


The lower stem leaves are long, lance-shaped and wavy-edged, or they have short teeth separated by scalloped sinuses (see the last images before the photo notes). The upper leaves are shorter, alternate, long arrow-shaped and hug the main stem. Side branches arise from the points of attachment [axils].


Picris is a biennial, taking two years to reach maturity in sunny, open yards, fields and roadsides, and sometimes it survives another year or two as a short-lived perennial. It is related to Chicory (genus Cichorium) and both are in the Chicory subfamily (Cichorioideae).

Picris is found in isolated pockets across the Northeast into Canada, but primarily in New York and Pennsylvania. There is a disconnected invasion, again highly localized, in the Northwest from Washington to Alaska and another in Hawaii.


Photo notes: To make a leaf stand out, cast a shadow into the background. Use a tripod and a cable release [or the self-timer]. After aiming and setting the exposure [manual works best], move to throw your shadow into the background. After taking the shot, check the result and adjust as needed. I've also used notebooks and shirts to create shadows where I need them.
Lenses for this project were the 18-55mm kit lens and 100mm macro on a Canon XT.

Corrections, comments and questions are always welcome at northeastnaturalist@yahoo.com Connect with me on Facebook. In addition to my personal page (with the Gaillardia flower at the top), there is a photo/artist page, Dave Spier (photographic naturalist).

Thursday, August 9, 2012

Cormorants




Cormorants – © Dave Spier

If you’re a fisherman, “cormorant” is likely a four-letter word.  I suppose there are a few people other than birders who love them, but most probably don’t care one way or the other.

Cormorants are large, dark birds that can be mistaken for geese when flying.  Young birds are pale underneath with an orange bill and face. When swimming, the bill is raised at an angle.  At close range, you can see the small hook on the bill tip.  Nicknamed the “sea-crow” along the coast and “water turkey” inland, the common Double-crested Cormorant (Phalacrocorax auratus) gets its name from two tufts of feathers on the sides of the head just behind the eyes.  The feathers curl around and meet at the back, but they are often matted down and resemble a bump.

Cormorants are adept at both flying and diving.  Normally these activities require opposite adaptations, such as light-weight versus heavy.  The cormorant has evolved feathers that lack the waterproofing of other diving birds, so they become heavier underwater.  This allows them to submerge and catch fish, their primary diet, but once they’re done feeding, cormorants must find a perch to spread and dry their wings.  It’s common to see them sitting upright on a dock, piling or stump with their wings outstretched.  This is also the reason they must head south for the winter.  Florida and Alaska’s Aleutian Islands are the Double-crested Cormorant’s only year-round range.


Cormorants are widespread across the continental United States with the heaviest concentrations on all the coasts plus the Great Plains, lower Mississippi Valley and Great Lakes.  Check eBird for a current range map.

In some areas their population growth has been explosive which can affect local fisheries and fish farms. Fishermen have blamed them for declines in musky, Largemouth and Smallmouth Bass, Yellow and White Perch, and Walleye.  An old stomach-content survey of cormorants, done over a two-year period in all four seasons, showed the birds predominantly prey on small minnows, including shiners, flatheads and dace.  Directly ingesting game fish amounted to less than 5% of their diet, and that was limited to late summer.  That leaves the potential problem of reducing the bait supply, but in areas like west-central New York, where the water is either weedy or deep, the minnows have plenty of hiding cover.  It’s only along shorelines like the east end of Lake Ontario, where the water is shallow and relatively clear, that there is a real conflict.



Jewelweeds


Jewelweeds -- © Dave Spier

First off, they're not weeds.  They're attractive native wildflowers. Second, and this is unfortunate, they are not jewels.  The name comes from water's inability to wet the leaves, so after a rain or morning dew, beads of water rest on the surface and scatter light like diamonds.  The plant's alternate name, touch-me-not, refers to the small seed pods that spring open and eject the seeds if you touch them when plump and ripe.


There are two species based on color.The dangling, one-inch flowers [roughly the length and width] of the yellow version, also called Pale Touch-me-not (Impatiens pallida) have a tail-spur that points down.  It's mostly found in limestone regions with alkaline soils and prefers damp locations like wooded flood plains and shady ravines with a steady supply of moisture.


The orange species, a.k.a. Spotted Touch-me-not (Impatiens capensis) is spotted with reddish-brown and the longer spur curves under the tail.  It is normally common and widespread but given its preference for damp ground and ditches, it's struggling this year with the drought.  The ones in my woods have long withered and died.

Impatiens are succulents with translucent green stems.  Crushed leaves and stem juice (particularly from the Orange Jewelweed) are folk remedies for poison ivy rash, insect bites, nettles, minor burns and cuts.

Young shoots in spring and the stems and leaves in summer can be eaten as cooked greens.  Boil in two changes of water and discard the water.


Corrections, comments and questions are always welcome at northeastnaturalist@yahoo.com or connect through my Facebook page or my photo page.

Wednesday, August 1, 2012

Cardinal-flower

Ruby-throated Hummingbird at Cardinal-flower,
Montezuma Audubon Center, Savannah, NY

Cardinal-flower -- © Dave Spier

This native perennial grows wild along streambanks and in swamps and other wet places up and down the eastern half of the U.S., northeast into Canada and south to Columbia. Look for it at the Montezuma Audubon Center (Rt. 89 N, Savannah, NY) where it grows along Crusoe Creek and also around the building where it has been planted to attract hummingbirds. The plant can reach two or three feet in height, making it a nice addition to any garden.

The Cardinal-flower (Lobelia cardinalis) gets its name from the bright-red blossoms hugging the upper stem. (Although sometimes called a spike, it is technically a raceme because of short flower stalks called pedicels.) Look closely at an individual corolla [flower] and you’ll notice three wide lobes forming a lower lip while two narrow lobes extend to the sides like arms. The male and female parts, also scarlet colored, form a narrow tube emerging like a crane above the petals. It looks custom-made to work with hummingbirds!


There was a hummingbird at these Cardinal-flowers when Donna and I first stopped on the boardwalk at Tinker Nature Park (Hansen Nature Center) in Henrietta, NY.













Cardinal-flower leaves are lance-shaped, long-pointed and serrated or toothed on the edges and they alternate on a single, main stalk. The plant contains alkaloids and should be considered toxic, as are other members of the genus Lobelia. In spite of this, Native Americans used root and leaf teas for various ailments. Cardinal-flower and its relative, the blue-violet Great Lobelia (another moist-ground species growing at the MAC) belong to the Lobelia subfamily of the Bluebell family.

Corrections, comments and questions are always welcome at northeastnaturalist@yahoo.com  Now you can connect through my Facebook photo page at Dave Spier (photographic naturalist) or my personal page, Dave Spier, northeast naturalist