Monarch butterfly migration starting in North America


This video is about monarch butterfly migration.

From eNature Blog in the USA:

The Monarch Butterflies Migrating Now Aren’t The Ones You Saw Last Spring

Posted on Thursday, August 28, 2014 by eNature

Fall is just around the corner throughout most of North America.

You’ve probably noticed that your local birds are preparing for it— and so are our many of our butterflies.

Monarch butterflies are famous for their annual migrations. Some of these insects travel thousands of miles each fall—an astonishing distance for such fragile creatures.

Yet few people realize that the Monarchs we see in the spring are not necessarily the same ones that fluttered past in the fall.

Beginning in late September, the skies along the Gulf Coast of Texas slowly become filled with meandering groups of Monarchs. Their flight, while not hurried, is purposeful, moving southwest toward a small forest in the highlands of Central Mexico. These butterflies travel from southern Canada and the northern United States at a rate of approximately 50 miles per day. They’ll spend the winter in a few small groves of evergreen trees, with each grove containing as many as 20 million butterflies. Sheltered from the wind and snow, the butterflies conserve energy, for they still have a lot of work ahead of them.

The Monarchs become active again in February. Mating begins, and the air fills with swirling masses of copulating pairs. The first warm days of late March trigger their northward flight. A close look at these butterflies, now eight months old, reveals that their wings are faded and tattered. Still, the Monarchs fan out across the southern United States, looking for Milkweed plants on which to deposit their eggs.

Four days later, the eggs hatch, producing small caterpillars that immediately begin to feed on the Milkweed leaves. Ten to fifteen days later, each caterpillar stops feeding and forms its chrysalis—a beautiful soft green jewel flecked with gold. In another ten to fifteen days the chrysalis splits open, and a new Monarch emerges.

This generation of butterflies mates, lays eggs, and dies within the span of a few weeks. During this time it moves north, following the progress of spring and the emergence of Milkweed.

By the end of summer, two more of these short-lived generations will have repeated the process, ultimately coming to inhabit the Milkweed patches in the far north latitudes.

Thus the Monarchs born in the Northeast and Canada in September are the great great grandchildren of the last Monarchs to inhabit the area. These are the ones that will head to Mexico. They’re significantly larger than the three generations that preceded them and still sexually immature. Rather than mate and lay eggs, they seek out nectar-producing flowers. The nectar serves two purposes: some of it fuels the southward migration, and some of it is converted to fat reserves that sustain the butterflies through the winter.

This incredible annual cycle applies to all Monarchs east of the Rockies. The populations in the West follow a similar pattern, though their migratory path is westward, from the Great Basin to overwintering sites along the Pacific Coast.

Since 1992 MonarchWatch has been carefully tracking Monarch Butterflies as they migrate.  Much of their data comes from the work of volunteers who tag and track the butterflies. They can always use more helpers…..

Are you seeing butterflies in your neighborhood?

Bring flowers, birds, bees back to meadows


This video, by BirdLife in the Netherlands, says about itself (translated):

August 25, 2014

Farmer Bink’s Rich Meadow: ‘Sowing the seeds of love for the birds and the bees‘.

Farmer Bink wants the flowers, bees and birds back into his pasture. Help him! Share this movie and sign the petition here.

One of the bird species which biodiverse meadows in the Netherlands attract are golden plovers in winter.

Three bug species discovered, new for Texel island


This video is called True Bugs.

Today, warden Erik van der Spek, on Texel island in the Netherlands, writes about bugs.

Recently, biologists discovered three species, new for the island, of this insect group, .

Temnostehus pusillus was found in the Bollekamer nature reserve, in the western dunes.

Rhacognathus punctatus, the heather bug, was discovered in the Horspolder, in the south of Texel.

Cyphostethus tristriatus, juniper shield bug, was found on a juniper shrub in the sand dunes.

This brings the number of Texel bug species to 313; about half of all bug species in the whole Netherlands.

Bugs photos: here.

Honey bee reproduction, new research


This video is called Honey Bees – Life Cycle.

From Wildlife Extra:

Researchers discover what causes honeybees to prepare for reproduction

When a colony of honeybees reaches the first stage in its reproductive cycle it builds a special type of comb used for rearing male reproductive bees, called drones. But what triggers that first stage?

A team of experts from the Department of Neurobiology and Behaviour at Cornell University, led by Michael Smith, set out to answer that question, reports the journal Naturwissenschaften – The Science of Nature.

Reproduction isn’t always a honeybee colony’s top priority. Early in a colony’s development, its primary focus is on survival and growth.

However, when the colony reaches a certain stage, its workers start investing in reproduction. The first step is building cells of drone comb, the special comb made up of large cells in which the drones are reared.

Drones develop from unfertilised eggs. Their sole purpose in a colony is to mate with virgin queens from other colonies, thereby spreading the genes of the colony that produced the successful drones.

Virgin queens in turn need to mate with drones before they can lay fertilised eggs that will become worker bees.

Queens will mate with over a dozen drones during their single nuptial flight, after which they are stocked with sperm for life.

Smith and his team were puzzled about precisely which colony features kick-start this key process of drone comb building.

Is it the number of workers in the colony? Is it the total area of worker comb? Or is it the number of brood in the colony? Or the size of the colony’s honey stores?

The Cornell University researchers found that while every colony built worker comb (non-reproductive comb), not every colony built drone comb (reproductive comb).

They discovered that an increase in the number of workers stimulated them to start constructing drone comb. This was seen whenever colonies contained 4,000 or more worker bees.

The researchers are still left wondering about precisely how an individual worker bee ‘knows’ how many other workers there are in its colony.

They speculate that this might have to do with how crowded individuals feel while working side-by-side in the hive. Further research is currently being conducted to shed more light on this mystery.

“Colonies with more workers built a greater proportion of drone comb, whereas colonies with more comb, more brood, or more honey stores, did not do so,” Smith said. “We estimate that a colony needs approximately 4,000 workers to invest in building drone comb.”

The researchers believe that their findings are also relevant to other social systems in which a group’s members must adjust their behaviour in relationship to the group’s size.

Rare butterflies wintering in the Netherlands


This is a scarce tortoiseshell video from Finland.

In July 2014, there was an invasion in the Netherlands of scarce tortoiseshell butterflies; a species, new for the Netherlands.

Soon, people did not see these rare, usually east European, butterflies any more. Did they fly on to England, or to Belgium? A few scarce tortoiseshells were seen there indeed; but how about all the others?

On 2 August 2014, warden Luc Knijnsberg was in Dutch nature reserve Bergen Zuid. Then, a thunderstorm started. Luc entered an old World War II bunker, now used by bats for wintering. In that bunker, he found thirteen wintering peacock butterflies (yes, August is a summer month, but for some butterflies, winter then starts already). Luc found not only peacocks, a common species, but to his surprise also two scarce tortoiseshells. So, this solved the riddle why so many of them arrived in the Netherlands; and so few in Belgium or England.

So, people counting wintering bats should look out for scarce tortoiseshells as well.

White beetles reflecting light, new study


This video is called Super White Beetle Holds Secret To Whiter Paper And Computer Screens?

From New Scientist:

Beetles so bright, you gotta wear shades

16:33 15 August 2014 by Philippa Skett

What is whiter than white? These beetles, apparently – because their scales make them whiter than paper. No human technology can match their brilliance using such thin material.

The scales of the Cyphochilus and Lepidiota stigma beetles, which are native to South-East Asia, contain tight, complex networks of chitin filaments. Chitin is a substance with a similar molecular structure to cellulose, and it builds the cell walls of fungi and the shells of crustaceans as well as insect exoskeletons.

On their own, the chitin filaments reflect light poorly. But researchers at the University of Cambridge and the European Laboratory for Non-linear Spectroscopy in Florence, Italy, have found that the geometry of a filament network makes the whole thing reflect light extremely efficiently. It reflects light of all colours anisotropically, meaning that it bounces the light in one direction only. That makes the beetles’ scales appear bright white.

“These scales have a structure that is truly complex, since it gives rise to something that is more than the sum of its parts,” said team member Matteo Burresi of the Italian National Institute of Optics in Florence. “A randomly packed collection of its constituent elements by itself is not sufficient to achieve the degree of brightness that we observe.”

What sets the brilliant beetles apart from artificial reflectors, though, is that the scales are ultra-thin. Their individual chitin filaments are just a few thousandths of a millimetre thick, minimising weight and so reducing the energy the beetles need to fly. It may not be too long before these beetles are inspiring a host of new materials that will be whiter than white too.

Journal reference: Scientific Reports, DOI: 10.1038/srep06075.

Two new moth species discovered in the Netherlands


This is an Aedia leucomelas video from Italy.

The Dutch Butterfly Foundation reports today discoveries of two moth species, new for the Netherlands.

One of these is Aedia leucomelas. An individual of this species was found in 1987 near Urmond village, and landed in a butterfly and moth collection. Only now researcher Rob de Vos discovered that moth was this south European and Asian species, which had never been recorded in the Netherlands before.

On 20 July this year, in Friesland province, there was nightly moth research. Over 110 macro moth species were counted. Among them was an Eucarta virgo. This east European and Asian species was new for the Netherlands as well.