Pecos River east of Iraan, TX 2019-08-26

On my way back from the Davis Mountains Hummingbird Celebration last week I stopped at a neat looking access spot on the Pecos river, just east of Iraan (pronounced "Ira Anne") on highway 190. It was a clear hot day, the temperature was over 100 degrees at about 1:15 PM when I stopped there. Soon after I parked by the river I was glad I had my water shoes with me because the water was clear and flowing over a rocky bottom. I wanted to wade in it!

Pecos River Selfie

I was surprised to find a few species I normally associate with the Texas coast. Soon after I got out of the car I spotted a few Marl Pennant dragonflies "obelisking" on high branches:

Marl Pennant - 1

Obelisking is a behavior dragonflies use to regulate their heat. In sunny hot conditions they will often point their abdomens straight up at the sun to minimize the surface area presented to the sunlight. This keeps them a little cooler.

Soon afterwards I noticed many beautiful little fishes with sparkly blue napes and vertical stripes on their sides all over in the shallow water. I couldn't get my camera to focus well on them past the surface of the water, but here's one of them:

Sheepshead Minnow - 1 - 1

These were the males, all defending small territories above the gravelly bottom where they occasionally mated with less colorful females. They chased away other males and smaller fish who were trying to eat their recently fertilized eggs. Here's an iPhone video showing some of this behavior:

Sheepshead Minnows video

I'm still waiting for confirmation from more knowledgable folks than myself, but I'm pretty sure these were Sheepshead Minnows, a species associated with brackish water along the gulf and atlantic coast. What are they doing here?

There was a larger fish species, about six inches long, in the deeper water. My current best guess is that these were Gulf Killifish, another coastal species. Here's one of them:

Gulf Killifish - 1 - 4

One of the last animals I spotted was a small black dragonfly. I vaguely remembered that my Texas Dragonflies field guide showed some inland populations of Seaside Dragonlets, and I was pretty sure that's what this was. Seaside Dragonlets are usually very common on the coast and they are the only north American species of dragonfly that can reproduce in salt water. Here's the one I found:

Seaside Dragonlet - 1 - 2

So what are these coastal species that like brackish and salt water doing way out here on the Pecos river in west Texas?

This morning back in Austin I had the annoying and expensive chore of having to buy new car tires. I was waiting in line at Discount Tire and started chatting with they guy in front of me who turned out to be a geologist specializing in Texas ground water consulting (Allan Standen). While we were waiting for our cars at at a nearby coffee shop, I told him about my recent observations on the Pecos River near Iraan. He told me that back in the 1940s, just north of Iraan was an important area for oil production during World War II. Deep salty ground water was pumped up to flush oil reservoirs, and probably made the surface water brackish in that area to this day. (He's a remarkable guy, and has some amazing visualizations of aquifer levels here.) That explains why these coastal species like it out there on the Pecos.

My field guide for fresh water fishes in Texas shows Sheepshead Minnows and Gulf Killifish both occurring in this area and says their presence here is because of deliberate introduction. But I wonder how the Seaside Dragonlets and Marl Pennants got there.

There were a few more odonates I photographed and I got some great photos of a Swainson's Hawk soaring overhead. See that attached observations.

And here are the same photos on Flickr.

Posted by mikaelb mikaelb, August 31, 2019 23:50

Observations

Photos / Sounds

Square

What

Eastern Ringtail Erpetogomphus designatus

Observer

mikaelb

Date

August 26, 2019 01:51 PM CDT

Description

On my way back to Austin from Fort Davis I stopped at a really neat access point of the Pecos River just east of Iraan. Despite triple digit temparature I spent over an hour wading in the clear water and photographing odonates, fish, and a beautiful juvenile Swainson's Hawk. I was surprised to find three species I normally associate with the Texas coast: Marl Pennant and Seaside Dragonlet dragonflies, and Sheepshead Minnow fishes.

Photos / Sounds

Square

What

Eastern Ringtail Erpetogomphus designatus

Observer

mikaelb

Date

August 26, 2019 02:00 PM CDT

Description

On my way back to Austin from Fort Davis I stopped at a really neat access point of the Pecos River just east of Iraan. Despite triple digit temparature I spent over an hour wading in the clear water and photographing odonates, fish, and a beautiful juvenile Swainson's Hawk. I was surprised to find three species I normally associate with the Texas coast: Marl Pennant and Seaside Dragonlet dragonflies, and Sheepshead Minnow fishes.

Photos / Sounds

What

Familiar Bluet Enallagma civile

Observer

mikaelb

Date

August 26, 2019 01:24 PM CDT

Description

On my way back to Austin from Fort Davis I stopped at a really neat access point of the Pecos River just east of Iraan. Despite triple digit temparature I spent over an hour wading in the clear water and photographing odonates, fish, and a beautiful juvenile Swainson's Hawk. I was surprised to find three species I normally associate with the Texas coast: Marl Pennant and Seaside Dragonlet dragonflies, and Sheepshead Minnow fishes.

Photos / Sounds

What

Gulf Killifish Fundulus grandis

Observer

mikaelb

Date

August 26, 2019 01:39 PM CDT

Description

On my way back to Austin from Fort Davis I stopped at a really neat access point of the Pecos River just east of Iraan. Despite triple digit temparature I spent over an hour wading in the clear water and photographing odonates, fish, and a beautiful juvenile Swainson's Hawk. I was surprised to find three species I normally associate with the Texas coast: Marl Pennant and Seaside Dragonlet dragonflies, and Sheepshead Minnow fishes.

Photos / Sounds

Square

What

Marl Pennant Macrodiplax balteata

Observer

mikaelb

Date

August 26, 2019 01:19 PM CDT

Description

On my way back to Austin from Fort Davis I stopped at a really neat access point of the Pecos River just east of Iraan. Despite triple digit temparature I spent over an hour wading in the clear water and photographing odonates, fish, and a beautiful juvenile Swainson's Hawk. I was surprised to find three species I normally associate with the Texas coast: Marl Pennant and Seaside Dragonlet dragonflies, and Sheepshead Minnow fishes.

Photos / Sounds

Square

What

Marl Pennant Macrodiplax balteata

Observer

mikaelb

Date

August 26, 2019 01:33 PM CDT

Description

On my way back to Austin from Fort Davis I stopped at a really neat access point of the Pecos River just east of Iraan. Despite triple digit temparature I spent over an hour wading in the clear water and photographing odonates, fish, and a beautiful juvenile Swainson's Hawk. I was surprised to find three species I normally associate with the Texas coast: Marl Pennant and Seaside Dragonlet dragonflies, and Sheepshead Minnow fishes.

Photos / Sounds

Square

What

Powdered Dancer Argia moesta

Observer

mikaelb

Date

August 26, 2019 01:56 PM CDT

Description

On my way back to Austin from Fort Davis I stopped at a really neat access point of the Pecos River just east of Iraan. Despite triple digit temparature I spent over an hour wading in the clear water and photographing odonates, fish, and a beautiful juvenile Swainson's Hawk. I was surprised to find three species I normally associate with the Texas coast: Marl Pennant and Seaside Dragonlet dragonflies, and Sheepshead Minnow fishes.

Photos / Sounds

Square

What

Powdered Dancer Argia moesta

Observer

mikaelb

Date

August 26, 2019 01:30 PM CDT

Description

On my way back to Austin from Fort Davis I stopped at a really neat access point of the Pecos River just east of Iraan. Despite triple digit temparature I spent over an hour wading in the clear water and photographing odonates, fish, and a beautiful juvenile Swainson's Hawk. I was surprised to find three species I normally associate with the Texas coast: Marl Pennant and Seaside Dragonlet dragonflies, and Sheepshead Minnow fishes.

Photos / Sounds

What

Seaside Dragonlet Erythrodiplax berenice

Observer

mikaelb

Date

August 26, 2019 01:59 PM CDT

Description

On my way back to Austin from Fort Davis I stopped at a really neat access point of the Pecos River just east of Iraan. Despite triple digit temparature I spent over an hour wading in the clear water and photographing odonates, fish, and a beautiful juvenile Swainson's Hawk. I was surprised to find three species I normally associate with the Texas coast: Marl Pennant and Seaside Dragonlet dragonflies, and Sheepshead Minnow fishes.

I vaguely remembered that Seaside Dragonlets occurred inland somewhere in west Texas. So I was excited to find this male.

Photos / Sounds

What

Sheepshead Minnow Cyprinodon variegatus

Observer

mikaelb

Date

August 26, 2019 01:22 PM CDT

Description

On my way back to Austin from Fort Davis I stopped at a really neat access point of the Pecos River just east of Iraan. Despite triple digit temparature I spent over an hour wading in the clear water and photographing odonates, fish, and a beautiful juvenile Swainson's Hawk. I was surprised to find three species I normally associate with the Texas coast: Marl Pennant and Seaside Dragonlet dragonflies, and Sheepshead Minnow fishes.

Photos / Sounds

What

Sheepshead Minnow Cyprinodon variegatus

Observer

mikaelb

Date

August 26, 2019 01:30 PM CDT

Description

On my way back to Austin from Fort Davis I stopped at a really neat access point of the Pecos River just east of Iraan. Despite triple digit temparature I spent over an hour wading in the clear water and photographing odonates, fish, and a beautiful juvenile Swainson's Hawk. I was surprised to find three species I normally associate with the Texas coast: Marl Pennant and Seaside Dragonlet dragonflies, and Sheepshead Minnow fishes.

Photos / Sounds

What

Swainson's Hawk Buteo swainsoni

Observer

mikaelb

Date

August 26, 2019 01:48 PM CDT

Description

On my way back to Austin from Fort Davis I stopped at a really neat access point of the Pecos River just east of Iraan. Despite triple digit temparature I spent over an hour wading in the clear water and photographing odonates, fish, and a beautiful juvenile Swainson's Hawk. I was surprised to find three species I normally associate with the Texas coast: Marl Pennant and Seaside Dragonlet dragonflies, and Sheepshead Minnow fishes.

I was excited to see this juvenile Swainson's hawk suddenly flying over me and got a few photos. Because of the extremely bright conditions and a little luck, these are the best flight shots I've ever gotten of a bird.

Photos / Sounds

Square

What

Kiowa Dancer Argia immunda

Observer

mikaelb

Date

August 26, 2019 01:28 PM CDT

Description

On my way back to Austin from Fort Davis I stopped at a really neat access point of the Pecos River just east of Iraan. Despite triple digit temparature I spent over an hour wading in the clear water and photographing odonates, fish, and a beautiful juvenile Swainson's Hawk. I was surprised to find three species I normally associate with the Texas coast: Marl Pennant and Seaside Dragonlet dragonflies, and Sheepshead Minnow fishes.

Photos / Sounds

Square

What

Kiowa Dancer Argia immunda

Observer

mikaelb

Date

August 26, 2019 01:32 PM CDT

Description

On my way back to Austin from Fort Davis I stopped at a really neat access point of the Pecos River just east of Iraan. Despite triple digit temparature I spent over an hour wading in the clear water and photographing odonates, fish, and a beautiful juvenile Swainson's Hawk. I was surprised to find three species I normally associate with the Texas coast: Marl Pennant and Seaside Dragonlet dragonflies, and Sheepshead Minnow fishes.

Comments

Thumb

Enjoyed your post. Interesting about the salt water.

Posted by connlindajo almost 2 years ago (Flag)
Thumb

Quite an interesting story. You completed the final piece to the puzzle and Allan Standen serendipitously appeared to help you out.

Posted by sawwhet almost 2 years ago (Flag)
Thumb

Thanks for the comments! On Facebook @dianaterryhibbitts commented. "That salt water runs from north of Red Bluff Reservoir to the the junction of independence creek."

Posted by mikaelb almost 2 years ago (Flag)

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