Word beasts: an arms race

 

About 65 million years ago, is the accepted estimate for when bat echolocation first appeared on the scene. This was the beginning of a long and protracted arms race between the bat hunters, and the hunted, the insects. For a bat, the nocturnal insects of choice are the moths. Plentiful, and with large fat bodies which make them quite attractive. It helps that they are also easy to find; their wings are great reflectors of the ultrasonic frequencies that bats use to find them, flagging them up against the clutter in a bats sonic world.

Way back in evolutionary time, the moths responded to their new predators. In the beginning simply, by evading the bat attacks with crazy evasive diving maneuvers. Then, with more sophisticated methods; ears that were tuned with great precision and sensitivity to the bats very high pitched cries. The very echolocation cries that the bats used to find moths now immediately alerted their prospective prey to their presence.The moths could now dive and circle away well in advance of the swooping bat.

In response, the bats called more softly, they started whispering, and changing the pitch signatures of their calls. They tried their very best to make echolocation calls that the moths could not easily detect or discriminate the direction of. The moths kept up their part of the race too, the pressure not to become supper being quite high. They changed the shape of their wings so their main body would not be attacked and just the edges of their wings would be taken. Some even started making sounds of their own! Sounds that either jammed bat sonar or made them sound unappetising, the acoustic equivalent of very red berries. And in return, its seems that some bats have responded by finding prey by the sounds of the prey alone and silencing their echolocation calls. And so, on it goes. 

And on goes the research, starting with the work of Brock Fenton, way back in the late 70's, right up to today with many different groups still working on different aspects of the same behaviour and ecology! Including the work of fellow post-doc Holger Goerlitz, who helped me do this beast. If you want to know still more about this cool co-evolutionary arms race, you could do worse than read this lovely review (if you can get behind the paywall).

Copyright © Natasha Mhatre If you're reading this without attribution to me anywhere other than at my blog Talking Pictures, its probably being plagiarized.

URL: http://feedproxy.google.com/~r/blogspot/wcEO/~3/H8KGzO9CCX8/word-beasts-bat-and-moth-coevolution_25.html

Using the Camera GPS to find the Sunken Church In San Miguel

I've now been in San Miguel de Allende for almost 6 weeks, about half way through our winter stay here. I have been enjoying all flavours and experiences that this city has to offer. I've even experienced some of the standard tourist events such as fighting with the Aztec gods (Montezuma of course). This laid me low for a few days but unfortunately after a few days when I thought I was getting better I developed a secondary infection that required visiting the doctor and getting medication. Now after 2 weeks I'm finally starting to get the spring back in my step and venturing back out. This does curtail your photography.

But back to the GPS item. Several weeks ago my friend Mike took me out to see the sunken church on the large shallow lake south-east of San Miguel.  The lake is really a reservoir and during the dry season, winter here, the church becomes fully visible.  The ground is still too mucky to be able to walk all the way out, but you can get close enough for some good shots.

If you look closely you can see some cacti growing out of the top portion of the church spire and therefore the church is not completely sunken.

What was really surprising when we first arrived was that we saw pelicans, which to many may not be unusual near water but this is at an elevation of 6,000ft and and 550 km from the nearest ocean.

I've been using on-camera GPS for almost 3 years, at least capturing the meta data with the image but I've never had to really use the info as until now I've always known exactly where I was. Not this time as this was new territory, so when I tried to use the Nikon format to enter into Google maps it took a while to find a site that would convert correctly.

Nikon gives a format such as:

Longitude:  20,52.1567N

Latitude:     100,50.1574W

Altitude:     1853m

Nikon is not DDD, MMM, SSS (Degrees, Minutes , Seconds but in format of DDD, MMM.MMMM)

Whereas Google maps required decimal degrees only in format DDD.DDDDD.

After some web searching I did find one site that would provide conversion in the Nikon format.

Nikon GPS Converter

In the Google map below the green arrow shows where I took the photo of the church above and the red arrow the top of church spire above the water.  This Google map (satellite view) was taken when the area was flooded. It is a bit strange to see that where you were standing is now underwater. A little north east of red arrow is a round ring. This is visible in the last photo of this article.

Towards the hill on the south-east in the map above is another church, not sunken but still abandoned.

Most of the foliage,except for the cacti at this time of year, is brown. This make a colour image rather drab. But converting to B&W and adding some contrast can make the photo stand out more.

In the image below the green cacti with a blue sky does make a colour version work better.

Below is the map and the green arrow shows where I was standing taking the photo above with the cacti.

As you can see the camera GPS is very accurate in capturing within feet where you where standing at the time when photograph is taken.

Another version of the sunken church where you can see the round ring that shows up beside the spire in the Google water map.

  Church with ring structure

Niels Henriksen

URL: http://feedproxy.google.com/~r/blogspot/kecE/~3/mo8aS_q7dkE/using-camera-gps-to-find-sunken-church.html

Another Hour at the Farm

Posted on February 4, 2012

Loading the Truck

Loading the Truck II

Auger

Small Barn

Keith

Starting the Truck

Swing

Steer

Calf

Looking for a Wrench

Shed Wall

Roger

Coffee Can

Little Farmer
Photo Info & Viewer Comments

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URL: http://feedproxy.google.com/~r/durhamtownship/~3/R6VBT7uDB1c/003638.html

Running interference

I'm on the familiar shore of a familiar sea just now. But I miss my river. The sullen muddy river with its tides and drowned shopping trolleys and bikes. It doesn't freeze, but the harbour does. Then the graceful and scornful swans waddle on frozen bits of water which cave under their weight. But its by the rivers banks that the cormorants swallow eels and the apples grow and I run, sometimes.

I missed the sea once, and still do but not this sea. Some mythical sea, where there is only the sound of the sea but none of traffic or people. Some mythical seashore on which there is a little girl who still waits for the gulls that are rare and come only in the winters.

Copyright © Natasha Mhatre If you're reading this without attribution to me anywhere other than at my blog Talking Pictures, its probably being plagiarized.

URL: http://feedproxy.google.com/~r/blogspot/wcEO/~3/a9tO8UPDBd8/running-interference.html