Readers’ wildlife

We have a potpourri again today. The first couple of photos are from reader Kevin Voges, who lives in Oz. His notes are indented. Imagine seeing these birds every day, as if they were pigeons or starlings in the U.S.!

Here’s a few more photos, this time from our place in Brisbane (Australia).

The first is a pale-headed rosella (Platycercus adscitus), first described by the English ornithologist John Latham in 1790, and native to northeastern Australia. This subspecies (palliceps) is also known as the blue-cheeked rosella.

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The other three are of the sulphur-crested cockatoo (Cacatua galerita), found in Australia, New Guinea and parts of Indonesia. You can see the “gang” that turn up most mornings for breakfast – there’s often a flock close to 100 in the sports field down the road.

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The bird perched on the gate is not just waiting his turn. As they are ground feeders, cockatoos have evolved a behavioural adaptation, with at least one of the flock on guard for predators. Old Australian slang used to refer to a person watching out for possible police raids on illegal activities as a cockatoo or cocky.

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The last photo is my favourite one – note the extended crest display.

The cage is an attempt to catch (in conjunction with the RSPCA) one of the cockatoos who is infected with Psittacine beak and feather disease (PBFD). Unfortunately, there is no cure and the virus can spread throughout a flock, so the bird needs to be removed. PBFD is a major threat to wild parrots, with most Australian native species affected.

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I’ve seen melanistic (black) squirrels in both Toronto and Ottawa, but here’s a true albino squirrel (note the pink eyes) taken in a park in downtown Toronto on June 30 by Steve Oberski:

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Steve noted this:

The woman who feeds this squirrel in the park at the behest of her employer—so that it does not continue to cross a busy street to beg for food at the restaurant where she works—requested that I not identify the specific location for, in her words, there were sickos in the area who would try to capture it.

What a great woman and boss!

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Finally, reader Don McCrady sent a lovely space photo; details are given both below and in the caption:

Here’s an astrophoto submission for your consideration.  This one is called The Crescent Nebula:

A powerful, yet dying Wolf-Rayet star is responsible for this formation of glowing dust and gas known as the Crescent Nebula (NGC 6888) in the constellation of Cygnus. The star, HD 192163 will eventually end its life as a supernova. The Crescent nebula lies about 5000 light years distant, near the bright star Sadr at the center of the constellation Cygnus.

This image was taken with a Stellarvue SVS130 telescope and an STL-4020M camera with Astrodon Hα and Oxygen-III filters. The colour channels were assigned as: Hα as red, OIII as green, and OIII+12%Hα as blue. The OIII exposure time was almost 7 hours, although the Hα exposure time was only 2 hours due to incoming clouds. The image was processed in Maxim DL and Photoshop CC, and upsampled 2x for the final result.

 

A powerful, yet dying Wolf-Rayet star is responsible for this formation of glowing dust and gas known as the Crescent Nebula (NGC 6888) in the constellation of Cygnus. The star, HD 192163 will eventually end its life as a supernova. The Crescent nebula lies about 5000 light years distant, near the bright star Sadr at the center of the constellation Cygnus. This image was taken with a Stellarvue SVS130 telescope and an STL-4020M camera with Astrodon Hα and Oxygen-III filters. The colour channels were assigned as: Hα as red, OIII as green, and OIII+12%Hα as blue. The OIII exposure time was almost 7 hours, although the Hα exposure time was only 2 hours due to incoming clouds. The image was processed in Maxim DL and Photoshop CC, and upsampled 2x for the final result.

17 Comments

  1. Jim Knight
    Posted July 2, 2016 at 8:53 am | Permalink

    The birds and squirrel are great photos, and the Crescent Nebula is just outstanding…!

  2. Diana MacPherson
    Posted July 2, 2016 at 9:48 am | Permalink

    Great photos all!

    I’ve seen that lookout behaviour with crows. Typically they will hang out in twos or threes and one will go up a tree and keep watch while the other crows forage. The guy keeping watch seems to decide when to leave as he will up and start flying away as the others catch up.

  3. rickflick
    Posted July 2, 2016 at 9:53 am | Permalink

    The nebula shot is really cool. I looked up the Stellarvue SVS130 to find it is a refractor telescope. I always thought the reflector style was most popular because of the large apertures possible. I’d be interested to know what advantage this camera would have over a mirrored type.

    • Don McCrady
      Posted July 2, 2016 at 10:17 am | Permalink

      The telescope is a refractor. For visual observing, a reflector its a better choice because you can cheaply build bigger mirrors. But reflectors aren’t great astrographs because they don’t produce flat photographic fields, unless you unload buckets of cash for a Ritchey-Chreitien.

      • Mark Sturtevant
        Posted July 2, 2016 at 10:26 am | Permalink

        Another general advantage of reflectors may be comfort of the viewer in typical situations. A refractor requires one to look thru the lens at the rear, and this may be near the ground if one is look at objects high in the sky.

      • Diana MacPherson
        Posted July 2, 2016 at 2:51 pm | Permalink

        Refractory make nice images though but to get a large aperture you pay a lot and you have a really long scope. SCTs address this but they aren’t as wide angle and you lose more light. Everything is a compromise, making astrophotography challenging and rewarding!

        • Don McCrady
          Posted July 2, 2016 at 4:28 pm | Permalink

          Good point Diana. An SCT is also an excellent choice and probably more versatile. With the correct equipment (e.g. Celestron HyperStar), an SCT can produce beautifully flat images. An ordinary SCT (without Hyperstar, at f/8 or f/10) is probably the best choice for planetary photography too.

          • rickflick
            Posted July 2, 2016 at 7:18 pm | Permalink

            I’d have to suspect many of the optical problems with reflectors could be addressed effectively with software. “Flat image” does not strike me as a really serious problem if the image can be manipulated after the fact. Of course, I’m not familiar with any of the specifics.

            • Don McCrady
              Posted July 2, 2016 at 7:46 pm | Permalink

              The optical problems can be corrected with expensive secondary mirrors. A Ritchey-Chretien design uses a hyperbolic secondary mirror to flatten the field, but that’s what makes it uber-expensive too. Once aberrations are committed to “film”, they can permanently hide details, and software corrections can actually introduce artifacts.

              • rickflick
                Posted July 2, 2016 at 7:52 pm | Permalink

                I think I understand. Everything’s better taken directly from the source.

    • ploubere
      Posted July 2, 2016 at 1:14 pm | Permalink

      Yes, very nice shot of the nebula.

    • gravelinspector-Aidan
      Posted July 2, 2016 at 6:32 pm | Permalink

      Great shot of the nebula. The blue fringes to the NW (you’re on conventional N-is-up and W-is-right orientation?) look really prominent, but they’re similarly prominent in the DSS2 blue channel. In fact, you’ve got considerably finer detail there than DSS has. The delicate lobes of blue emission out far to the NW aren’t in the DSS channel. They look like breakout lobes from early in the mass-loss phase of the WR central star.
      I’m using the ALADIN-LITE tool from the Uni.Strasbourg collection of astronomical databases. For those who haven’t been introduced to it, this is a useful tool for finding out what is already known about a particular “fixed” star (the databases don’t track planets and other mobile stuff). It’s a good way of avoiding re-inventing the wheel.

      • rickflick
        Posted July 2, 2016 at 7:50 pm | Permalink

        Astonishing!

      • Don McCrady
        Posted July 2, 2016 at 7:55 pm | Permalink

        Thanks. The image is oriented N-is-up; a good way to see this in context with DSS data is using World Wide Telescope. You can see this image in context in WWT at http://goo.gl/nYbdxB.

        The DSS data is taken at wide-band visual wavelengths which is why you don’t see as much detail as what shows up using narrowband filters like I’m using. The blue lobe loses a lot of contrast without an Oxygen-III filter to remove the rest of the blue signal.

        I also use Aladin to help plan my shots; it’s a great resource.

        • gravelinspector-Aidan
          Posted July 2, 2016 at 10:44 pm | Permalink

          Aladin, SIMBAD and VizieR – you could almost believe that someone had read “The Naming of Hosts” (RFC 2100) .

  4. Mark
    Posted July 2, 2016 at 11:12 am | Permalink

    Even here in the deep south of Australia where winter bites hard, the sulphur-crested cockatoos are prominent summer visitors. They arrive in spring in huge, and very loud, flocks.

    We also see the occasional black cockatoo with a sulphur crest, but I’m not sure what species that is. Galahs, another cockatoo species, are also very common in our island state.

  5. Mark R.
    Posted July 2, 2016 at 4:14 pm | Permalink

    “Cocky”…too funny. I love how slang comes about.

    Great photos and info about the Aussie birds. I’d trade your Cockatoos for our pigeons any day!

    Neat squirrel.

    Stellar nebula photo! (Sorry about the pun, I couldn’t help myself.)


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