Author: Nature on the Edge

The Perfect Landing Pad

| Nature on the Edge

Recently while sitting in my garden observing various visitors – a little field mouse bolting for cover as a mongoose came stepping by, hadeda ibis trailing across the lawn in search of worms, my attention was diverted to the tree strelitzia’s (Strelitzia alba) blooms and a Cape sugarbird perching to drink nectar.  I dashed to get my camera to record the event in a happy glow of anticipation.  For a while i’ve been following the exciting developments of biomimicry and the innovative designs being inspired by nature.   See a previous post on the structure of the dragonfly’s wings.    Janine Benyus’s excellent book published in 1997 “Biomimicry: Innovation Inspired by Nature” raised publicity around the subject of science studying nature for design solutions.   Coincidentally i came across Sarah van der Walt’s  http://www.biomimicrycapetown.co.za for the latest innovations of the industry here in the Mother City.

Back to the action in my garden – i wanted to capture the effect of the elasticity of the petals which bend to expose the anthers and then smoothly counter bend to close the nectary. In this example the strelitzia flower is aligned perpendicular to it’s stalk providing a perfect perching spot for birds.  Notice the mid-rib extending just beyond the bird’s left foot?  It’s flexible design allows the petals to ‘pop’ open and expose the anther filaments covered in pollen.   While it imbibes the sweet nectar the bird’s feet are covered in pollen which will then be transferred to the next flower in the process of pollination.

Cape sugarbird perches on the landing pad of the tree strelitzia.
Cape sugarbird positioned to sip nectar.

There are five different species of strelitzia.  Also growing in pride of place in my garden is the classical beauty – Strelitzia reginae with it’s gorgeous orange and purple/blue flowers encased in a sturdy colourful spathe as featured below –

Out of curiosity at seeing how the petals spring open I decided to dissect a couple of the flowers to reveal how the structure of the joined petals operated under the weight of the bird.  A midrib runs freely along a groove so that it flexes and allows the parting of the two halves to pop open.  When the bird flies off the petals realign again.

In 2011 an interesting project headed by Simon Schleicher of the University of Stuttgart and a team of researchers came up with the “Flectofin”  – a hingless louvre system, based on the studies and principles abstracted from the strelitzia plant.   Neat!

As i watch the birds flitting between the blooms in this garden at the bottom end of Africa, how awe inspiring it is to reflect on the genius of nature.

The perch -two blue petals form a casing for the filament anthers and midrib.
Dissection showing the flexible midrib and the feathery anthers.

 

The exposed anthers showing pollen encrusted filaments.

 

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Spring: new tweets

| Nature on the Edge

Spring has wafted in bringing some relief from the drought as swathes of wild flowers stretch across the veld.  There’s an air of triumph about  – a flap of wings and the squawking of little hatchlings.   A welcome sight in our backyard is a newly fledged Cape wagtail chick.  It plopped out of the nest like a little plum pudding and landed with a bump. The parents continue to fuss around encouraging it to fly, following with encouraging tweets.

Initially there was a setback with the first nest when it was abandoned after the local baboon troop came for a visit through the neighbourhood. They’d spent a week constructing a perfect little structure and had just lined it with soft feathers when the furry visitors rudely clambered right up the very jasmine creeper where it was sited and partially dislodged it in their rush to jump over the wall.  The birds were so spooked that they took off and disappeared for a while before returning to choose a new site to rebuild.  Happily there was a successful outcome and if the pattern of past years is repeated the adult pair may well produce two more batches of chicks this season.

Heron poised to strike

| Nature on the Edge

The brief this week from Cheri is to catch that instant before an event  – “A photograph often captures the moment — the exact second that two lovers kiss on a street corner, or a gymnast extends both legs in mid-air into a perfect split, or a hummingbird hovers over a flower to drink its nectar. But some of my favorite images are quiet and still; they focus on the moment before the action and capture the anticipation, or the rumination, or the calm before the storm.”

Here in an intense moment, a Grey heron is waiting to strike and spear a fish in the shallows.

WPC: Waiting

 

Little Jack

| Nature on the Edge

It’s not every day a chance like this comes along to admire the exquisite details of the world’s smallest mouse species Mus minutoides.    Here he is sitting in a corner, (WordPress Photo Challenge) though not eating Christmas pie.

There is a story attached to this scene:  a family of Cape pygmy mice have taken up residence in my neighbour’s kitchen and to outwit the little beauties, the man of the house came up with an ingenuous design for a trap.  This is no ordinary mouse trap, it’s a deluxe model, the spacious 5***** Hilton of mouse traps.  If you’d like to read about the delightful battle of wills between man and mouse here is the link  to “Our Urban Wild” blog post. The catering service is excellent too – seeds,  grated cheese and a miniature water bowl are provided.  My task is to release the captured creatures to a carefully chosen location.  Where we hope they continue to multiply.  With a gestation period of just 20 days and the young weaned and independent at 4 weeks the population growth can be robust.

Further reading extract from Wikipedia –

“Grey to brick-red overall, it is pale on the underside and has small but prominent triangular ears. Adults are between 30 and 80 mm (1.2 and 3.1 in) long, with a 20 to 40 mm (0.79 to 1.57 in) tail, and weigh from 3 to 12 g (0.11 to 0.42 oz).

African pygmy mice reach breeding age at about 6 to 8 weeks. Pregnancy lasts for around 20 days and the litter of about 3 young is born blind and hairless. Their eyes open after 2 weeks, and weaning is complete after 4 weeks. The lifespan is about 2 years, although individual specimens have been reported to live over 4 years in captivity.

The African pygmy mouse has a number of unique traits. It stacks pebbles in front of its burrow. Overnight the pebbles gather dew and in the morning the pygmy mouse drinks the dew on the pebbles. After that it retires back to its den. Its method of sex determination has also been found to differ from most mammals[2] in that rearrangements of the X chromosome have led to many XY individuals actually being female.”