Golden highlights

  

Western Meadowlark (Sturnella neglecta), Bodega Head, 12 November 2022

Bright spot

 

Western Meadowlark (Sturnella neglecta), Bodega Head, 31 October 2019

Splashes of white -- Part 2

Okay, here are the mystery feathers from last night:

 

I realize that was tough because there's not much context, so here are a few hints.

I encountered the feathers in a coastal grassland.  Along with the feathers shown above, some had even more white:

 

Most of the other feathers in the area were brown with darker barred patterning.  The longest feathers I found were ~5-6 inches (12-15 cm) long.

 

 

I was moving along, scanning the various feathers, trying to put together a picture of the bird's identity.  Along with the tail and wing feathers shown above, there were brownish body feathers with somewhat similar colors and markings:

 

Then I looked ahead and spotted some feathers that clinched the identification.  I think the next photos will help you figure out the identity of this medium-sized grassland bird, too:

 

 

The bright yellow and black body feathers, along with the large amount of white on the outer tail feathers, leads to Western Meadowlark (Sturnella neglecta). 

John mentioned the U.S. Fish and Wildife Service's Feather Atlas as a resource for identifying feathers.  Here's an example of meadowlark tail feathers from the Feather Atlas.  And here's a link to some older photos of Western Meadowlarks on Bodega Head.

I don't recall encountering meadowlark feathers before.  It was fun to see the patterns up close.  I also wondered what happened to it — who caught the meadowlark?  A falcon?  A harrier?  Have you seen a predator chasing adult meadowlarks?  

(I just tried to learn more about meadowlark predators.  Along with falcons, I was somewhat surprised to see Great Egret and Burrowing Owl listed as possible predators on adult meadowlarks.  Who knew?)

Calling from Petaluma

I recorded some fun bird calls and songs in Petaluma this weekend.

Do you want to try to guess which species of birds they are?

I'll reveal the answers at the end of this post.

[If you're reading this in an e-mail, click on the title of the post above to go directly to the website to see the audio files.]

Be sure to turn up the volume of your speakers. (Listening with headphones is even better.)
 

Here's Sound 1.  There are some background sounds, but listen for the hollow, knocking notes.  You'll hear three different series of these notes —  at about 3 seconds, 10 seconds, and 16 seconds.

Here's Sound 2.  In this case you'll also hear three different series of notes, but this time the notes are loud whistles and gurgles.





Here's Sound 3.  There's some background sound, but focus on the clear, whistled note.  You'll hear the note five times — at about 1, 4, 6, 9, and 11 seconds.




Okay, are you ready for the answers?


Sound 1: Common Raven (Corvus corvax).  This is sometimes referred to as a percussion-like call.  Some liken it to a drumming woodpecker.  It's apparently only given by females.

Sound 2: Western Meadowlark (Sturnella neglecta).  An impressive vocal array.

Sound 3: Loggerhead Shrike (Lanius ludovicianus).  I don't know much about shrike vocalizations, but I was intrigued by this beautiful call note.  I couldn't find a good written description of it, and only came across one other recording that was somewhat similar.  Have you heard shrikes calling like this?  Is it a sound that just hasn't been described very well?  Or is there geographical variation in shrike call notes?

Now that you've heard the shrike, here are two pictures of the individual that was calling:

 

 

And the meadowlarks were eating...

I know, you've been wondering all day about the mystery food item featured in last night's post!  ;)

To review, here's the close-up that showed a Western Meadowlark holding a white squiggly thing with a brown object at one end:

 

I mentioned that I went out to the same area and dug around just like a meadowlark to try to find the same sort of object.  It didn't take very long!  I started finding them almost immediately.  I kept digging to see if there was more than one option, but this is the only match I found.

I brought it into the lab and took a few photos under the microscope.  The first shows the brown object with the white shoot off to the side, and the second is a closer view of a slightly larger brown object:

 

 

While digging, I also looked around to see if there was ever anything else at the other end of the shoot, and that was easy enough to find.  Below is an example.  It was a little too long for a microscope view, so I bent it around so you could see both ends:

 

And here's one of just the leaves of this plant (different individual), which might help with the identification:

 

This is Oxalis pes-caprae.  It has a variety of common names and is often known as Bermuda Buttercup.  But I like the name African Wood-sorrel, as it's originally from South Africa and although it has yellow flowers, it's not a buttercup!

Oxalis pes-caprae is known for having relatively large bulbs (but less than 2.5 cm long) from which underground shoots arise in the fall.  In fact, this species is invasive and difficult to eradicate because of the many bulbs that it produces.

I was a little surprised to find out that meadowlarks were eating Oxalis bulbs!  But I was also taken aback by the color and texture of the lower surface of the Oxalis leaves!  

In the field, many of the leaves were green below, but others were bright pink, as in the image above.  I couldn't help taking a closer look under the microscope.  I know it's a bit of a tangent, but you have to see this!

 

 

 

 

Isn't that amazing?  I looked at descriptions of Oxalis, and none of them mention this color.  Or that the leaves are glandular.  [I'm not sure what else this could be (other than glandular), but if you have different ideas, let me know.]  CORRIGENDUM 9 November 2013: I've done some additional research, and now believe these are bladder cells.  I'll explain a bit more later.

To wrap up, I'll go back to the main topic of this post — the Oxalis bulb being a food source for meadowlarks.  Out of curiosity I split open one bulb to see what the meadowlarks were after (see below).  When I first started watching the meadowlarks a few days ago, I had no idea it would lead me to the inside of an Oxalis bulb!

 

Watching my nemesis

Western Meadowlarks (Sturnella neglecta) are common winter residents in grasslands on Bodega Head.  Occasionally I've tried to photograph them, but they're quite wary, and I haven't had much luck.  Every time I almost get close enough for a picture, they take off and land just a little farther away and disappear among the vegetation.  When it comes to getting a good picture, they're a bit of a "nemesis bird" for me.  I just shake my head and sigh.

This weekend I was at work and I passed by a window to see a small group of meadowlarks very close by.  I wasn't sure how long they would stay in the area, or if it would be possible to photograph them through the window, but I decided to give it a try.  It was basically like being in a blind.

It was a fascinating experience.  I'd never watched meadowlarks feeding before!  The pictures aren't sharp because of the window and the fast movements of the meadowlarks, but they're still informative, so I'm excited to share them with you.

The meadowlarks would stride quickly across the ground.  I like this next picture because it emphasizes the strong and slightly curved bill.

 

They would use their bill to probe deeply into the vegetation or the ground.  The picture below also highlights the beautiful feather markings.

 

Sometimes they would open their mandibles and use their bill to flip over clumps of vegetation:

 

Digging with the bill was common.  In the image below, look for the soil being flung to the right side of the bird.  The meadowlarks were vigorous when digging, and now I understand how useful their strong bills are for this type of feeding behavior.

 

I saw them with food in their bills quite often, but it was difficult to identify the food items.  I feel fairly confident that this meadowlark found a large beetle larva (within blue circle in image below):

 

But the most common food item was mysterious at first.  While I was watching, all I could see were thin white squiggles in the meadowlarks' bills.  And then when I reviewed the pictures, I could see that sometimes there was something brown at the end of the white squiggle.  

Can you see the squiggles in the bills of the two birds in the pictures below?  And that the uppermost bird is holding onto a brown object at one end of the squiggle?  (You can click on the images for slightly larger versions.)

 

Close-up of the uppermost bird:

 

I know this is difficult because you don't have a lot to go on, but do you have any guesses about what the white squiggles might be?

The next day I went out and dug around myself to figure this out.  But I'll give you a chance to think about it, so I won't reveal the answer until tomorrow.

For now I'll leave you with two more pictures of meadowlarks — one stretching its wing and tail (showing the white outer tail feathers), and the other with a meadowlark in a crouched position (revealing that incredible yellow throat).