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Monday, April 30, 2012

The Very Large Array

A couple months ago when I was on my way to Tucson, I stopped overnight at Socorro, New Mexico.  Some 50 miles/80 kms. northwest of there, along Hwy 60, is the Very Large Array....


of radio telescopes, that is.


Dedicated in 1980, the Very Large Array (VLA) has been an extraordinarily productive scientific instrument. Astronomers from around the world use it to study objects from our Solar System to the edges of the known Universe, billions of light-years from the Earth.


The telescope array consists of twenty-seven, 230-ton, 25-meter diameter dish antennas.  The data from the antennas is combined electronically to give the resolution of an antenna 36km (22 miles) across, with the sensitivity of a dish 130 meters (422 feet) in diameter. For more information, see our overview of the VLA. The array is currently in the D configuration.


The VLA has made key observations of black holes and protoplanetary disks around young stars, discovered magnetic filaments and traced complex gas motions at the Milky Way's center, probed the Universe's cosmological parameters, and provided new knowledge about the physical mechanisms that produce radio emission.


The VLA is now being transformed into a new research instrument: the Expanded Very Large Array (EVLA). By 2012, new state-of-the-art electronics and software will have completely transformed the VLA into the EVLA, a much more capable research tool with more than ten times the VLA's sensitivity. Reinvigorated by new technologies, the EVLA will push the frontiers of science and knowledge for decades to come.




The VLA is located on the Plains of San Agustin, the site chosen because of the isolated location away from large population centers, and the partial shielding effect of the surrounding mountain ranges.

Geologically, the Plains of San Agustin lie within the Mogollon-Datil volcanic field, just south of the southeast edge of the Colorado Plateau, and west of the Rio Grande Rift Valley. The basin is a graben (a downdropped block which subsided between parallel faults). The graben is younger than the Datil-Mogollon volcanic eruptions. The flat floor of the plains was created by a Pleistocene lake (Lake San Agustin). Although the graben has dropped an estimated 4,000 ft., the surface relief has been reduced to about 2,000 ft. by sedimentation. A great deal of the sediments entered the San Agustin basin prior to the formation of Lake San Agustin in the last glacial period. There is no evidence of tectonic activity in the area after Lake San Agustin became extinct.

The edges of the plains have sites of archaeological interest such as a prehistoric rockshelter known as Bat Cave.

Other sites in the area include a ghost town called Old Horse Springs and the Ake Site, a prehistoric occupation site. 


And, wow, was it ever windy the morning I visited the VLA and drove through the Plains of San Agustin!  Too windy (and cold) to do the walking tour at the VLA - another time.....I will return. 



No, the VLA is not involved in SETI, or the Search for Extraterrestrial Intelligence.  But, at least one UFO researcher believes the Plains of San Agustin was a site of a UFO crash in 1974, but then this IS New Mexico and everything in southern New Mexico seems to be space-related.  I love it.


I lifted all of the above information directly from some of the websites listed below:

Official site of the VLA:

Wikipedia




Monday, April 23, 2012

White-tailed Deer

A birding drive yesterday produced a lot of new birds - shorebirds are starting to show up.  I found some Semipalmated Sandpipers, Lesser Yellowlegs and a good number of Marbled Godwit pairs.  I don't have a good photo of any.  

On days such as yesterday, I'm pretty much birder-only, remembering to grab the camera only after I've gazed long through the binoculars or scope.

Several White-tailed Deer (Odocoileus virginianus) were grazing near sloughs in the early morning.  I managed to capture one with tail-flag waving.



These American Coots (Fulica americana) were intent on their mating rituals.  A lot of preening and stamping of the reed platform by the male.  Coots are amazingly interesting to watch.  


American Avocets (Recurvirostra americana) have been arriving in the area the past week, which was really cold, rainy and windy.  I expect by tomorrow (after two days of very warm, sunny weather) the shorelines will be much alive with these elegant creatures.





 

Friday, April 13, 2012

Arizona & New Mexico Guide Books

Before I forget, and as I get things put away and tidied up from my trip down to Arizona, I want to share a few great guide books. 

This latest edition of the Tucson Audubon publication, Finding Birds in Southeast Arizona, is an invaluable asset for the travelling birder. 


It gives a lot of trip planning advice, including some tips about visiting Mexico.  The book is set out in areas.  For example, Chapter 1 is Urban Tucson, giving explicit directions how to get to all birding areas within the city and birds you might expect to see (given the season).  I visited a good many of the areas outlined in Chapter 8, Huachuca and Whitestone Mountains, and the Upper San Pedro River Valley. 

Get this book before you go to Southeastern Arizona, period!  There are 372 pages of info, including adverts for various B&Bs and birder-friendly businesses.

Ditto this one, from Richard Taylor, published by American Birding Association, Inc.
  

Taylor compiles information in terms of destination areas; he supplies maps with trails well marked (in some cases, there are tear-out maps in the back so you don't have to take the entire book on long hikes).  

There is some information overlap with these two books, but each adds to the magnificent birding experience of SE Arizona. 

Both books are available on-line at:
http://www.tucsonaudubon.org/nature-shops.html

As with the above Arizona books, this one for New Mexico is a must. 


 I picked this up several years ago.  It is available from the New Mexico Ornithological Society on-line.  It is laid out in counties, shows maps of each county with the parks/locations.  Location write-ups includes an extensive list of birds likely to be found and when.  At 351 pages including index, there is a lot of info in this book.

Here are two Birding Trail maps that really help the visiting birder plan the trip.  Definitely get them before travelling. 


This National Audubon field guide is simply the best for the all-round, very curious travelling nature-lover.


It generally explains the area geology, has a section on rocks, mosses & lichens, plants (shrubs, trees, cacti, flowers), and features the common birds, insects, reptiles, mammals of the region.  There are even some star maps for those nights outside marvelling at the magnificent starry sky.  It is nicely sized to go along in a pocket or backpack.

All of these books are available at the various park gift shops as well.

Tuesday, April 10, 2012

Cock (Pheasant) Fight!

Today, along a road I was slowly driving; looks like a younger fella (on right) decided to take on a handsome older chap.


That's the older one in the air


The older one on left


And the older fella attacking.


Ring-necked Pheasant  Phasianus colchicus

Monday, April 2, 2012

Pyrrhuloxia

The Pyrrhuloxia (Cardinalis sinuatus)  is a relative of the more widely-known Northern Cardinal.  A couple of local names are Desert Cardinal and Silver Cardinal.  This is a bird of the scrub deserts of Mexico, western Texas, and the southern parts of Arizona and New Mexico.


The male Pyrrhuloxia look quite a lot like the female Northern Cardinal, but with more rosy red in the face and chest and different beak shape.  The Pyrrhuloxia beak is quite parrot-like.  These close relatives sound much alike, with the Pyrrhuloxia's song being a little higher pitched and clipped. 


These particular photos were taken at San Pedro House in mid-March.  This male is rather dull, not yet having his bright Spring/Summer breeding colours. 

Its name of Pyrrhuloxia - once part of its latin name - comes from Greek terms describing its coloration (πυρρος = pyrrhos = reddish or orange) and the shape of its bill (λοξος = loxos = oblique). (obviously from Wikipedia


These birds prefer scrub desert but also close to water.  The riparian habitat along the San Pedro is ideal.  They are pretty much non-migratory, however in Winter some may wander outside their usual range.  That usual range is also expanding northward, benefitting from agricultural and other human influences (now that's something one doesn't hear very often!).   Visit Wikipedia or All About Birds (links below) or check out your North American bird guide books for range and more about these birds.


The above bird was at San Pedro as well, but along the river.  I found Pyrrhuloxias everywhere I visited in SE Arizona.  They readily come to seed feeders.  Their wild diet is seeds, fruits and insects. 

For more info about this bird species, hear the bird song, etc, visit:

http://www.allaboutbirds.org/guide/pyrrhuloxia/id
http://www.allaboutbirds.org/guide/pyrrhuloxia/lifehistory
http://en.wikipedia.org/wiki/Pyrrhuloxia