Understanding through Discussion


Welcome! You are not logged in. [ Login ]
EvC Forum active members: 80 (8960 total)
122 online now:
Newest Member: Mikee
Post Volume: Total: 869,189 Year: 937/23,288 Month: 937/1,851 Week: 60/321 Day: 22/38 Hour: 8/5


Thread  Details

Email This Thread
Newer Topic | Older Topic
  
Author Topic:   Road Trip - Dragonflies - Photography - Geology
Tanypteryx
Member
Posts: 2332
From: Oregon, USA
Joined: 08-27-2006
Member Rating: 3.8


Message 31 of 69 (786442)
06-21-2016 9:14 PM


I am not sure if there is a specific name for very thin layers of strata like this sandstone in Canyonlands National Park.

I took this shot to show that there are places where close observation reveals that the layers were not deposited in flat, level, continuous layers, but are sometimes thicker in places and thinner in others and sometimes thin out to nothing.

I found places where thin layers had "de-laminated" from the underlying layers and were like a flexible membrane when you walked on them.


What if Eleanor Roosevelt had wings? -- Monty Python

One important characteristic of a theory is that is has survived repeated attempts to falsify it. Contrary to your understanding, all available evidence confirms it. --Subbie

If evolution is shown to be false, it will be at the hands of things that are true, not made up. --percy


  
Tanypteryx
Member
Posts: 2332
From: Oregon, USA
Joined: 08-27-2006
Member Rating: 3.8


(3)
Message 32 of 69 (786608)
06-23-2016 9:54 PM


And now for something completely different
Well, not completely different, but a species I have never posted here before. Hagenius brevistylus is one of the largest dragonflies in North America and it preys primarily on other dragonflies, hence the common name Dragon Hunter. It is always on my target list of species I want to photograph whenever I am in the eastern U.S. I found this female on the Middle Fork of the Stones River near Murfreesboro, TN.

This species is in the family Gomphidea or Clubtails and they are mostly stream specialists. Normally they like to land on stones in the stream or on leaf surfaces of streamside vegetation, but Hagenius prefers the tips of twigs. Note the use of the hind femur and tibia to grasp the perch that is typical for this species. As far as I know, no other species grasps the perch like this.

The primary reason I went to Tennessee was to meet some friends and search for a dragonfly that was seen by one of them a few years ago. It was the largest dragonfly he had ever seen in a 55-year career of studying them, so he knew it was an undescribed species and unknown to science. We spent most of a week in southern TN near the Alabama border looking for this critter. We saw it a number of times, always flying away from us (after it had passed us), but we never got a close look or a chance to swing a net. A second team took over when we left and they even tried mist nets in which the caught a number of other large species but not the target. My friend who originally made the first observation was suffering from a lower back disk problem and another friend got a bad leg cramp on the 3rd night and the next day it was badly swollen and painful. We ended up taking him to the ER because we were worried about blood clots. He was clear but it put him out of commission for the rest of the trip. After a few days it turned all black and blue and yesterday he told me it is still quite painful. It just seemed to be an ill-fated trip.

It was frustrating to not get any photos or specimens and we were unable to locate a likely nymph habitat either. We'll get it next year.


What if Eleanor Roosevelt had wings? -- Monty Python

One important characteristic of a theory is that is has survived repeated attempts to falsify it. Contrary to your understanding, all available evidence confirms it. --Subbie

If evolution is shown to be false, it will be at the hands of things that are true, not made up. --percy


  
Tanypteryx
Member
Posts: 2332
From: Oregon, USA
Joined: 08-27-2006
Member Rating: 3.8


(1)
Message 33 of 69 (786883)
06-28-2016 7:33 PM


What are the mechanics of the erosion process here?
The canyons cut into the Permian White Rim Sandstone surrounding Island in the Sky in Canyonlands National Park have this general pattern. They end in what you might call clusters of blind canyons. It looks obvious that they were not cut simply by a river flowing through. The ones pictured here are associated with the Green River that can be seen in places.

It looks like there are small dry streams that would flow to the head of each canyon and then form a waterfall dropping into the canyon.

Could it be that these canyons were cut by ice and snow meltwater during the last ice age and that further erosion in the present is mostly limited to flash floods from thunderstorms?

The Green and Colorado rivers meet south of here and the Colorado has similar canyons on its eastern side of Island in the Sky.

Edited by Tanypteryx, : spelling


What if Eleanor Roosevelt had wings? -- Monty Python

One important characteristic of a theory is that is has survived repeated attempts to falsify it. Contrary to your understanding, all available evidence confirms it. --Subbie

If evolution is shown to be false, it will be at the hands of things that are true, not made up. --percy


Replies to this message:
 Message 34 by 14174dm, posted 06-29-2016 12:38 PM Tanypteryx has acknowledged this reply

  
14174dm
Member
Posts: 151
From: Cincinnati OH
Joined: 10-12-2015


Message 34 of 69 (786922)
06-29-2016 12:38 PM
Reply to: Message 33 by Tanypteryx
06-28-2016 7:33 PM


Re: What are the mechanics of the erosion process here?
Never been out West - fascinating geology.

I would love to hear how the canyons formed. I can't quite work it out with my limited geology.

I assume very resistant surface layer underlined by very soft layers.

Huge flows or looonnnggg time to erode down leaving the buttes (second picture) and flat valley floor.
I would think the hoodoos in the lower center of third picture would indicate low velocity flows or shallow flows limited to canyon floor. The canyons seem to be following the existing stream network so I would assume they date after the glacier melt.

Or I could be clueless.


This message is a reply to:
 Message 33 by Tanypteryx, posted 06-28-2016 7:33 PM Tanypteryx has acknowledged this reply

  
Tanypteryx
Member
Posts: 2332
From: Oregon, USA
Joined: 08-27-2006
Member Rating: 3.8


(4)
Message 35 of 69 (786996)
06-30-2016 8:22 PM


Closer to home
I spent a couple hours out at my favorite pond this morning testing a custom fill flash diffuser with bright sun giving me some backlight to bring out the fine hairs.

If there is a better way to spend a morning, I haven't found it. This is a male Sympetrum illotum, common name Cardinal Meadowhawk.

The red on the abdomen of this species is so saturated that I have to desaturate it to keep fine details.

Edited by Tanypteryx, : No reason given.


What if Eleanor Roosevelt had wings? -- Monty Python

One important characteristic of a theory is that is has survived repeated attempts to falsify it. Contrary to your understanding, all available evidence confirms it. --Subbie

If evolution is shown to be false, it will be at the hands of things that are true, not made up. --percy


Replies to this message:
 Message 36 by Pressie, posted 07-01-2016 9:12 AM Tanypteryx has acknowledged this reply

  
Pressie
Member
Posts: 2082
From: Pretoria, SA
Joined: 06-18-2010


(1)
Message 36 of 69 (787028)
07-01-2016 9:12 AM
Reply to: Message 35 by Tanypteryx
06-30-2016 8:22 PM


Re: Closer to home
It's beautiful.

As a child I was raised to believe that dragonflies were really bad things. I believed that they could sting and attack and kill everyone around and all that stuff. I killed thousands of them just because they were around rivers and pools and ponds; everywhere where there's water around.

OMG, I really, really was stupid.

Edited by Pressie, : No reason given.


This message is a reply to:
 Message 35 by Tanypteryx, posted 06-30-2016 8:22 PM Tanypteryx has acknowledged this reply

  
Tanypteryx
Member
Posts: 2332
From: Oregon, USA
Joined: 08-27-2006
Member Rating: 3.8


(1)
Message 37 of 69 (787186)
07-06-2016 10:30 PM


Another dragonfly trip with some other stuff thrown in
I'm picking my longest time dragonfly friend (met in 1983 and have been traveling together ever since) at the Portland airport Friday night and we are headed for a dragonfly society meeting in Utah. Two weeks of two old guys rocking out from one aquatic habitat to the next. A couple days with some others doing a dragonfly blitz at Zion National Park, then main meeting and field trips around Salt Lake City.

It looks like we will have some good presentations of scientific research at our one day main meeting and lots of good habitats to explore the rest of the time.

It is gratifying to see how many students we have in the younger generations who are using Odonates as their research subjects. I am lucky to still have many friends that I've known for more than 25 years who are coming to our annual and regional meetings.


What if Eleanor Roosevelt had wings? -- Monty Python

One important characteristic of a theory is that is has survived repeated attempts to falsify it. Contrary to your understanding, all available evidence confirms it. --Subbie

If evolution is shown to be false, it will be at the hands of things that are true, not made up. --percy


Replies to this message:
 Message 38 by Pressie, posted 07-07-2016 7:31 AM Tanypteryx has not yet responded
 Message 39 by Pressie, posted 07-07-2016 7:33 AM Tanypteryx has acknowledged this reply
 Message 40 by ringo, posted 07-07-2016 12:11 PM Tanypteryx has not yet responded

  
Pressie
Member
Posts: 2082
From: Pretoria, SA
Joined: 06-18-2010


Message 38 of 69 (787195)
07-07-2016 7:31 AM
Reply to: Message 37 by Tanypteryx
07-06-2016 10:30 PM


Re: Another dragonfly trip with some other stuff thrown in
Basically a duplicate of the next comment.

Edited by Pressie, : No reason given.

Edited by Pressie, : No reason given.


This message is a reply to:
 Message 37 by Tanypteryx, posted 07-06-2016 10:30 PM Tanypteryx has not yet responded

  
Pressie
Member
Posts: 2082
From: Pretoria, SA
Joined: 06-18-2010


(1)
Message 39 of 69 (787196)
07-07-2016 7:33 AM
Reply to: Message 37 by Tanypteryx
07-06-2016 10:30 PM


Re: Another dragonfly trip with some other stuff thrown in
Tanypterix, what I find where I live, I get lots of dragonflies with the back parts of their bodies being blue flying around the fish pond. I used to think that they were something like big mosquitos.

It's basically a swimming pool where I don't use chemicals while growing my kois because they are beautiful, too.
Artificial waterfall and all that also involved.

All those dragonflies I've seen have got deep blue backsides (or whatever you call those back segments).

Thanks for what you do here. I look at those dragonflies in a new light. And I look at what they do! They're beautiful.


This message is a reply to:
 Message 37 by Tanypteryx, posted 07-06-2016 10:30 PM Tanypteryx has acknowledged this reply

  
ringo
Member
Posts: 17820
From: frozen wasteland
Joined: 03-23-2005
Member Rating: 2.6


(1)
Message 40 of 69 (787207)
07-07-2016 12:11 PM
Reply to: Message 37 by Tanypteryx
07-06-2016 10:30 PM


Re: Another dragonfly trip with some other stuff thrown in
Tanypteryx writes:

...my longest time dragonfly friend....


I have library friends and bus stop friends and Tim Hortons friends. The closest I have to a dragonfly friend is you.

This message is a reply to:
 Message 37 by Tanypteryx, posted 07-06-2016 10:30 PM Tanypteryx has not yet responded

  
Tanypteryx
Member
Posts: 2332
From: Oregon, USA
Joined: 08-27-2006
Member Rating: 3.8


(4)
Message 41 of 69 (788236)
07-28-2016 12:21 AM


I'm back with photos of Tanypteryx
We had a fun trip to Utah and a great meeting. We participated in a dragonfly survey at Zion National Park and collected and photographed in some new habitats that we had not explored before. I was familiar with all the species we saw but we also collected nymphs and got eggs of several species that we will try and rear out to adults. My friend who I was traveling with is the North American authority on dragonfly nymphs and is finishing up a book on all the species. I was able to take him to a location in SE Oregon where we collected eggs from a species that has never had the nymph described, so if we are successful at rearing it, he will be able to include it in the book. He is missing only one other species that hopefully we can get before the book goes to press.

On the last leg of the trip we visited Todd Lake in the Cascade mountains, where I caught my first dragonfly when I was a boy. A couple years later I discovered the second known population of Tanypteryx hageni. Now we have documented more than 200 distinct populations scattered from far north in British Columbia to south in Yosemite National Park in the Sierras.

Tanypteryx hageni along with some of the other 10 species that make up the family Petaluridae live in burrows when they are nymphs. They construct the burrows in hillside boggy seeps and prey on small animals that venture too close to the opening. They spend five years as a nymph. The burrows of a mature nymph as in these shots is about 10mm across and can be 300mm deep.

This is the exuviae or cast off skin that is left behind when the dragonfly emerges and metamorphoses into an adult.

This is an adult male. They are attracted to light colored objects like rocks or weathered wood and use them as the center of their territory that they will defend against any interlopers.

I really love the pattern of light spots on the dorsal abdomen.

This is a copulating pair.

This is the view of Todd Lake and Mt Bachelor from the nymphal habitat.

Enjoy


What if Eleanor Roosevelt had wings? -- Monty Python

One important characteristic of a theory is that is has survived repeated attempts to falsify it. Contrary to your understanding, all available evidence confirms it. --Subbie

If evolution is shown to be false, it will be at the hands of things that are true, not made up. --percy


Replies to this message:
 Message 42 by NosyNed, posted 07-28-2016 2:02 AM Tanypteryx has responded

  
NosyNed
Member
Posts: 8887
From: Canada
Joined: 04-04-2003
Member Rating: 5.5


(4)
Message 42 of 69 (788238)
07-28-2016 2:02 AM
Reply to: Message 41 by Tanypteryx
07-28-2016 12:21 AM


Me too

I tried to wrap that in img tags but it won't work. But using that link I can view it on one drive.

How can I embed it?

Also, what are you camera settings for those images, please?

Edited by NosyNed, : No reason given.

Edited by NosyNed, : I google for one drive help for embedding.


This message is a reply to:
 Message 41 by Tanypteryx, posted 07-28-2016 12:21 AM Tanypteryx has responded

Replies to this message:
 Message 43 by Tanypteryx, posted 07-28-2016 2:39 AM NosyNed has responded
 Message 44 by NoNukes, posted 07-28-2016 5:35 AM NosyNed has not yet responded

  
Tanypteryx
Member
Posts: 2332
From: Oregon, USA
Joined: 08-27-2006
Member Rating: 3.8


Message 43 of 69 (788239)
07-28-2016 2:39 AM
Reply to: Message 42 by NosyNed
07-28-2016 2:02 AM


Re: Me too
A sweet image of Rhionaeshna multicolor, well done!

I am not sure how to embed your image. fkickr creates the db code for me.

The closeups were all taken with a Nikon D700 and 200mm micro-nikkor, f36@1/30, ISO 400, diffused flash.


What if Eleanor Roosevelt had wings? -- Monty Python

One important characteristic of a theory is that is has survived repeated attempts to falsify it. Contrary to your understanding, all available evidence confirms it. --Subbie

If evolution is shown to be false, it will be at the hands of things that are true, not made up. --percy


This message is a reply to:
 Message 42 by NosyNed, posted 07-28-2016 2:02 AM NosyNed has responded

Replies to this message:
 Message 45 by NosyNed, posted 07-28-2016 10:14 AM Tanypteryx has responded

  
NoNukes
Inactive Member


Message 44 of 69 (788241)
07-28-2016 5:35 AM
Reply to: Message 42 by NosyNed
07-28-2016 2:02 AM


Re: Me too
I tried to wrap that in img tags but it won't work. But using that link I can view it on one drive.

How can I embed it?

I enjoyed the picture. Maybe this will help you share it with others.

If you go to tinyurl.com you can get upload your image and in return be given an IMG tag that can be used to refer to the image. Images that I have put on that site several years ago are still available now.


Under a government which imprisons any unjustly, the true place for a just man is also in prison. Thoreau: Civil Disobedience (1846)

History will have to record that the greatest tragedy of this period of social transition was not the strident clamor of the bad people, but the appalling silence of the good people. Martin Luther King

I never considered a difference of opinion in politics, in religion, in philosophy, as cause for withdrawing from a friend. Thomas Jefferson


This message is a reply to:
 Message 42 by NosyNed, posted 07-28-2016 2:02 AM NosyNed has not yet responded

  
NosyNed
Member
Posts: 8887
From: Canada
Joined: 04-04-2003
Member Rating: 5.5


Message 45 of 69 (788249)
07-28-2016 10:14 AM
Reply to: Message 43 by Tanypteryx
07-28-2016 2:39 AM


Thanks
I found that one drive gives a different link for embedding than for sharing. So I don't have to put it somewhere else.

This was shot as aiming practice using a D500, 300 mm F/4 PF with 1.4 TC at 1/2000, ISO 900, f/8.
I'm going to experiment with much higher f-stops and slower shutter speeds. I had the speed set for hummingbirds.
Dragaonflies are my favourite insects by a mile.


This message is a reply to:
 Message 43 by Tanypteryx, posted 07-28-2016 2:39 AM Tanypteryx has responded

Replies to this message:
 Message 46 by Tanypteryx, posted 07-28-2016 11:52 AM NosyNed has responded
 Message 59 by arachnophilia, posted 07-30-2016 2:44 PM NosyNed has responded

  
Newer Topic | Older Topic
Jump to:


Copyright 2001-2018 by EvC Forum, All Rights Reserved

™ Version 4.0 Beta
Innovative software from Qwixotic © 2020