Monday, April 29, 2013

Spring cleaning

Ever since the snow melted off the sidewalks, piles of sand have been appearing between the cobbles. 

Entrances to an ant nest.
Some of these sand piles are ant-hills, produced by ants as they expand their underground tunnels.  Though miniscule to us, some of the sand particles are larger and heavier than the ants.  Nevertheless, the ants are able to carry these particles up and out of the nest, utilizing both their surprising physical strength and teamwork.

Ant workers moving sand out of the nest.
In addition to the ant nests, I found a few sand piles with much larger entrances -- and occupants.  To be continued...

Friday, April 26, 2013

Game over

Sometimes, it is the flower that gets bitten by the visitor.  Other times, it is the visitor that gets bitten.

A small crab spider eats a fly on a wood anemone (Anemone nemorosa) flower.
After searching hundreds of flowers, I was excited not only to see my first crab spider in Germany, but also to find it complete with prey.  However, since I realize that not everyone feels that a spider improves a flower, here is a view of some of those that were spider-free.

A patch of wood anemones (Anemone nemorosa) where just a few days ago I had only seen dry leaves.

Monday, April 22, 2013

Spring training, continued

As spring advances, the flowers quickly change.  The crocuses have already been replaced by daffodils, hyacinths, forsythia, common daisies, and many more.  Each flower has a different shape, and it can take some experimentation before a bee learns to handle the flowers efficiently.  For example, this bumble bee made an awkward attempt to drink nectar upside down...

A bumble bee (Bombus sp., likely pascuorum) visits a glory of the snow (Chionodoxa sp.) flower.
... before switching to a more conventional approach at the next flower.

The bumble bee tries a different approach.
For another bumble bee, it was not the approach -- but the flower -- that posed a problem.  Corydalis flowers (pictured below) have their nectar at the end of a long spur.  To get the nectar, it is necessary to have a tongue long enough to reach deep into the spur.

A  bumble bee (Bombus sp., either lucorum or terrestris) trying to drink nectar from a Corydalis sp. flower.
This bumble bee's tongue was not long enough, yet it did not give up.  The opening of the flower was too far from the nectar, so the bee made a new opening closer to the end of the spur.

The bumble bee chewing a hole through the spur of the flower.
Although the bee gets the nectar this way, it fails to provide a benefit to the plant: either by pollinating the flower or by picking up pollen to carry to the next flower.  Therefore, this behavior is known as "nectar robbing".  Not all potential pollinators are capable of chewing through flowers.  However, once a flower has been robbed, all subsequent visitors have the option of using the shortcut to any nectar that remains and to any new nectar that is produced.

A hole in another flower is visible above the bumble bee's foot.

Monday, April 15, 2013

Spring training

Although Sommerzeit did not begin auspiciously, a string of sunny days has quickly faded winter into a distant memory.  Instead of snow, the ground is now covered with early-spring flowers: snowdrops (Galanthus spp.), winter aconite (Eranthis hyemalis), glory of the snow (Chionodoxa sp.), and crocuses (Crocus spp.).

A purple crocus (Crocus sp.) blooming outside my building.
The crocuses especially are popping up in almost every green space -- yards, city parks, and even road medians -- enlivening the city with bright splashes of white, yellow, and many shades of purple. 

One of the many crocuses (Crocus sp.) blooming in a nearby park.
In some places, the crocuses are so dense that their flowers nearly carpet the ground.  In these areas, there is a steady traffic of honey bees and bumble bees collecting nectar and pollen from the blossoms.

A European honey bee (Apis mellifera) foraging at a cluster of crocuses.
However, on these first days of the foraging season, not all of the bees have been living up to their reputation as indefatigable workers.

A European honey bee (Apis mellifera) taking a break from foraging on the crocuses.

Monday, April 8, 2013

Sommerzeit

Leaving France, I traveled east to Berlin, Germany -- and even deeper into winter.  There were several inches of snow on the ground, with more falling almost every day.  After a few days, I received an email reminder that sommerzeit (literally, 'summer time') was about to start.  Looking out the window, I felt that sommerzeit was a cruel name for daylight savings time.

A snowy view from my window.
In my apartment, I was not the only one at the window waiting for spring.  When I opened one of the windows to check how cold it really was outside (very cold!), I found a lacewing that had been hiding in the crevice between the window and the windowsill.  Although the lacewing was brown in color, it was most likely a common green lacewing (Chrysoperla carnea), which fades to brown when it hibernates.

The lacewing I found hibernating in between the window and the windowsill.
At another window, I found a small beetle as it tried to climb the glass, fell, and rolled around on its back on the windowsill.  I helped the beetle back onto its feet, but decided to wait until it was warmer before letting the beetle out through the window.

A small beetle on the windowsill.
When the first day of sommerzeit arrived, I pulled open the curtains...

A snowy start to sommerzeit.
... only to see yet more snow falling.  Feeling disappointed but not at all surprised, I adjusted my clocks forward and left my short sleeve shirts at the bottom of the drawer.

Monday, April 1, 2013

The scourge of the spurge

On my last day in France, I stumbled upon a small garden that I had visited once (also while wandering around a bit lost) almost six years before.  I remembered the garden as being full of bright flowers and buzzing insects, but on this cold spring day everything seemed green and still.  However, as I continued along the narrow path, I discovered that not all of the green was simply foliage.  All along the back of the garden, spurge (Euphorbia sp.) plants were topped with light green inflorescences full of little flowers...

One of the many flies that I found visiting the spurge (Euphorbia sp.) flowers.
... and also surprisingly full of large flies, given the lack of pollinators everywhere else I had looked.  I began to get my hopes up -- where I could find flies, I might also be able to find a spider.  A few plants later, there it was: a small spider, but with a good chance of growing larger very soon.

A small spider lurking amongst the spurge flowers.