Trees - Bats and a Red Dragon

When the children were young we spent summer holidays in Pembrokeshire. We were fortunate to have the use of a static caravan owned by family. It was situated on a spacious site by the coast, surrounded by woodland. My husband warned our children to keep away from ‘the forest’ because a bright red dragon lived there. It was very fierce and snorted flames through huge nostrils. It was also very good at sniffing out children who were still awake after a certain time, apparently. The children weren’t quite sure about a dragon hiding in our trees, though they had seen plenty of Red Dragon themed items in the shops and didn’t doubt their existence. One day we were driving through the woods along the winding lane that took us to the main road when we saw a goat tethered to a tree.

“Oh look, there’s the dragon’s dinner!”  Said Dad to two horrified children.

Well, that was a step too far, especially when we returned later to find the goat no longer there.

When our children were a little older, they liked to be ‘scared’ by my husband stopping the car at night on the darkest stretch of the lane and turning the headlights off. No one wanted to be first to say ‘let’s go’ and get ridiculed by the others. It was usually me suggesting an end to silly games as it was nearly bed time. Nothing to do with fear, certainly not.

We never saw a real dragon but we did see the bats that lived in the trees. They flew around at dusk and we would watch them from the caravan veranda as we relaxed when the children were asleep after a fun-filled day.

Our children are now parents themselves. They still refer to the woodland near the caravan as the forest. If they ever visit with their little ones, I’m sure our legend of the Red Dragon will live on.
 

I was searching for a suitable poem about trees to add to my blog when vanity got the better of me and I looked no further than ‘The Tree in Pamela’s Garden’. Well, it had to be, didn’t it?

What I wasn’t expecting was eight pages of ‘A Literary Analysis’ about the fairly short poem.  The scrutiny kept me engrossed for a while, fascinated and amused with a bit of disbelief and lots of ‘What are they on about?’ or ‘What are they on?’ Either I’ve been away from education for too long, or I haven’t studied American poetry and poets enough.

 

 

The Tree in Pamela’s Garden

Pamela was too gentle to deceive
Her roses. “Let the men stay where they are,”
She said, “and if Apollo’s avatar
Be one of them, I shall not have to grieve.”
And so she made all Tilbury Town believe
She sighed a little more for the North Star
Than over men, and only in so far
As she was in a garden was like Eve.

Her neighbors—doing all that neighbors can
To make romance of reticence meanwhile—
Seeing that she had never loved a man,
Wished Pamela had a cat, or a small bird,
And only would have wondered at her smile
Could they have seen that she had overheard.

 

Edwin Arlington Robinson    1869 – 1935 Maine USA

If I had a proper tree in my garden, there would be also be a bench, like the picture. Not my photo, just looks appealing.

Thanks for reading, Pam x

 

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Hearing - I'm picking up good vibrations

My mother lost the hearing in her left ear when she was in her late thirties through Meniere's disease. It is a nasty condition that affects the inner ear, causing pressure, dizziness and nausea. The symptoms usually pass: Mum was not so lucky. It also seems to have reduced her sense of smell. Three years ago she was also diagnosed with macular degeneration affecting both eyes. The deterioration of her sight has been a terrible blow. She is losing her ability to read, to enjoy watching television and seeing faces. Now at 96, she depends on me more than ever.

We struggle with her hearing aid. If the volume is high it amplifies the background noise.  When we watch a programme together it is too loud for her, so the volume is off and I read the text too but often, because she can't see it, she switches off part way through. When we are in the car she loves to listen to classical music on the radio. It seems that the resonance of non-electronically produced music is easier to hear. I think she feels the vibration through the bones of her face. Thinking about this led me to do some research about bioacoustics. Please don't switch off just yet. You may find this interesting.

"Dolphins possess a highly sophisticated auditory system and a keen capability for echolocation. Signals are emitted in the form of high intensity, short duration, broadband exponentially decaying pulses. The frequency spectra of echolocation signals used by many dolphins are dependent on the output intensity of the signals and not on any fine tuning by the animals. When the output intensity is low, the center [sic]frequency of the click tends to be low. As the output intensity increases, the center frequency also tends to increase. The pulses propagate from the dolphin's melon in a relatively narrow beam, and echoes are received via the lower jaw, with a slightly wider beam.

Echo- locating dolphins can detect targets at ranges of approximately 100 plus meters, depending on the size of the targets. Target discrimination experiments have shown that dolphins can discriminate the shape, size, material composition and internal structure of targets from the echoes. The broadband, short duration properties of the signal allow the echoes to have high temporal resolution, so that within the structure of the echoes a considerable amount of information on the properties of the target can be conveyed.

A brief comparison between the bat and dolphin sonar system will also be made. Bats typically emit much longer signals and a wider variety of different types of signals than dolphins. Signals used by some bats are suited to detecting Doppler shift, whereas the dolphin signal is designed to be tolerant of Doppler effects." Whitlow W.L. Au (1997).  Echolocation in dolphins with a dolphin-bat comparison. Bioacoustics 8(1-2): 137-162

So what about bats then? You are going to ask - aren't you? Bats are not blind; in fact they can see almost as well as humans. But to fly around and hunt for insects in the dark, bats make calls as they fly and listen to the returning echoes to build up a sonic map of their surroundings. The bat can tell how far away something is by how long it takes the sounds to return to them. These calls are usually pitched at a frequency too high for adult humans to hear naturally. Human hearing ranges from approximately 20Hz (cycles per second) to 15 to 20 kHz (1000Hz) depending on age. In comparison, some bats can hear sounds up to 110 kHz in frequency. By emitting a series of often quite loud ultrasounds that either sweep from a high to low frequency or vary around a frequency, bats can distinguish objects and their insect prey and therefore avoid the object or catch the insect. Individual bat species echolocate within specific frequency ranges that suit their environment and prey types.

Many moons ago I took my children on a bat walk organized by the Wyre Rangers in Dolphinholme, (strange coincidence). We waited until twilight to see thousands of bats fly from the roof of a house and helped to estimate their numbers visually.  It was certainly not accurate science. The little beggars fly in circles. Later we went in the dark to stand close to a pond with bat-detectors and hears the clicks picked up by their inaudible high-pitched emissions as they dipped to catch bugs. We can only hear them using a type of hearing aid. 

Mum struggles to hear my voice.  It seems that she is tuned to a lower frequency and her comprehension is far greater when listening to deeper male voice.  Or perhaps even at 96 she prefers male company?  She certainly warms to the bass voice. As do I...

Echolocation 
 

When we met,

I admired your shape,  
I heard your voice
And something deep
began to resonate.

When we share

The dark, warm night,
I hear your smile,
And map your contours
with sweet kisses.

When we are apart,

I send my longing song,
So your vision finds
And overflows my
listening heart.

 

 Have a good week.  Thanks for listening. Adele

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