Nalle Bunny Run 2017-07-22

Three people joined me this morning for the monthly group walk on Hill Country Conservancy's Nalle Bunny Run Wildlife Preserve. When I arrived at the preserve at about 7:30 AM as soon as I got out of my car I saw and heard a large group of mostly Blue-gray Gnatcatchers making alarm calls in a small area in a cedar elm tree. I estimated there were ten gnatcatchers, more than I've ever seen together before. Other species of birds including Northern Cardinals, Carolina Chickadees, and even a hummingbird were all in the same small area watching very intently.

This is a defensive behavior small songbirds have when they find some kind of predator. The mobbing and scolding behavior is mostly to warn other birds and animals of the predator's presence, and also to try and drive the predator away. I carefully searched the area up in the tree where the birds were most concentrated. Often the gnatcatchers would hover in the air as well as perch on nearby twigs and branches. After several minutes of searching, and starting to wonder if there really was anything there for the birds to be worried about, I finally spotted this snake laying across the branches with its head hanging low:

Texas Rat Snake

The snake was a Western Rat Snake, a nonvenomous common and beneficial animal in the Austin area. This one was about two feet long. As I watched it, the original group of birds left, but periodically new birds would arrive and start the scolding and mobbing again. I was happy that the snake stayed there long enough for all the hikers to arrive. Everyone got the see the snake and the birds' alarm behavior around it. One of the birds that showed up was this almost completely bald Northern Cardinal:

Northern Cardinal

This time of year lots of songbirds are finished raising their broods and can now spend energy replacing their feathers (molting). It's common to see Northern Cardinals like this that lose all of their head feathers at once. They're appearance is quite alarming before their new feathers grow in. But most birds just look messy or disheveled while they're molting, as they lose and replace feathers at different times. This Carolina Wren that was also keeping an eye on the snake had this more common molting appearance:

Carolina Wren

Other highlights of the morning included this juvenile Red-tailed Hawk which we hard calling from near the spring long before we finally got this clear look at it from the northeast corner of the preserve:

Red-tailed Hawk

The hawk flew off shortly after I took this photo, but later on after we'd left this area it returned to this tree with a dramatic partial diving arial maneuver with half-folded up wings, right over our heads!

We briefly watched this large wasp digging in the sand. I thought it might be an Eastern Cicada Killer but I look forward to getting some help from the iNaturalist community to know for sure:

Digging Wasp - 1

Sometimes the air was full of dragonflies, mostly kinds that hunt on the wing like Wandering Gliders, Spot-winged Gliders, and Red Saddlebags. But we also found a Roseate Skimmer, a Neon Skimmer, and two Halloween Pennants (one male and one female). Here's the male:

Halloween Pennant - 2

We found 28 species of birds, and here's our complete list on eBird.

Here are a few more photos on Flickr.

And attached below are the photos as iNaturalist observations.

Posted by mikaelb mikaelb, July 22, 2017 21:51

Observations

Photos / Sounds

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What

Carolina Chickadee Poecile carolinensis

Observer

mikaelb

Date

July 22, 2017 07:38 AM CDT

Description

Taken during the monthly group walk on Hill Country Conservancy's Nalle Bunny Run Wildlife Preserve.

This Carolina Chickadee was one of the many birds mobbing the Texas Rat Snake in this cedar elm tree.

Photos / Sounds

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What

Carolina Wren Thryothorus ludovicianus

Observer

mikaelb

Date

July 22, 2017 07:39 AM CDT

Description

Taken during the monthly group walk on Hill Country Conservancy's Nalle Bunny Run Wildlife Preserve.

This molting Carolina Wren was one of the many birds mobbing the Texas Rat Snake in this cedar elm tree.

Photos / Sounds

What

Horse Guard Wasp Stictia carolina

Observer

mikaelb

Date

July 22, 2017 09:12 AM CDT

Description

Taken during the monthly group walk on Hill Country Conservancy's Nalle Bunny Run Wildlife Preserve.

This wasp was digging in the sand when we found it. I thought it might be covering up an existing hole. My first guess is that it's an Eastern Cicada Killer because of the black and yellow pattern on its abdomen, but it didn't look big enough.

Photos / Sounds

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What

Great Spreadwing Archilestes grandis

Observer

mikaelb

Date

July 22, 2017 08:59 AM CDT

Description

Taken during the monthly group walk on Hill Country Conservancy's Nalle Bunny Run Wildlife Preserve.

Photos / Sounds

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What

Halloween Pennant Celithemis eponina

Observer

mikaelb

Date

July 22, 2017 09:11 AM CDT

Description

Taken during the monthly group walk on Hill Country Conservancy's Nalle Bunny Run Wildlife Preserve.

Female Halloween Pennant

Photos / Sounds

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What

Halloween Pennant Celithemis eponina

Observer

mikaelb

Date

July 22, 2017 09:38 AM CDT

Description

Taken during the monthly group walk on Hill Country Conservancy's Nalle Bunny Run Wildlife Preserve.

Male Halloween Pennant

Photos / Sounds

What

Ladder-backed Woodpecker Dryobates scalaris

Observer

mikaelb

Date

July 22, 2017 08:50 AM CDT

Description

Taken during the monthly group walk on Hill Country Conservancy's Nalle Bunny Run Wildlife Preserve.

The female Ladder-backed Woodpecker below was feeding the begging male above. I assume the male was a fledgling.

Photos / Sounds

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What

Northern Cardinal Cardinalis cardinalis

Observer

mikaelb

Date

July 22, 2017 08:13 AM CDT

Description

Taken during the monthly group walk on Hill Country Conservancy's Nalle Bunny Run Wildlife Preserve.

This molting Northen Cardinal was one of the many birds mobbing the Texas Rat Snake in this cedar elm tree.

Photos / Sounds

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What

Red-tailed Hawk Buteo jamaicensis

Observer

mikaelb

Date

July 22, 2017 09:01 AM CDT

Description

Taken during the monthly group walk on Hill Country Conservancy's Nalle Bunny Run Wildlife Preserve.

We heard this juvenile Red-tailed Hawk calling long before we saw it. Finally we got a pretty good look at it perched in this dead cottonwood tree on the sandy prairie area.

Photos / Sounds

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What

Western Ratsnake Pantherophis obsoletus

Observer

mikaelb

Date

July 22, 2017 07:30 AM CDT

Description

Taken during the monthly group walk on Hill Country Conservancy's Nalle Bunny Run Wildlife Preserve.

As soon as I arrived at the preserve I saw and heard a group of about 10 Blue-gray Gnatcatchers and other birds alarming in a cedar elm tree. This was the most gnatcatchers I've ever seen in one group, and they were all concentrated around the same small area, sometimes hovering in the air. After much searching I finally found this Texas Rat Snake which was the object of their attention. The snake was still there after the walking group arrived and we all enjoyed seeing the snake and the birds' reactions to it.

Comments

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Very interesting. Haven't seen a bald cardinal before and didn't realize they molted like that. Thanks for sharing.

Posted by oz4caster almost 4 years ago (Flag)
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Great photos especially the wasp. What an eventful hike!

Posted by sawwhet almost 4 years ago (Flag)
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nice group of photos!

Posted by blubayou almost 4 years ago (Flag)

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