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Welcome to Brazos Bend State Park. That's me on the trail. One of the most popular reasons for people to visit BBSP is to see the birds. Although I started going to the
park mainly for the alligators, one cannot be there for long without learning to enjoy the birds. Over the years, I've captured a few pictures and video clips of them, and
over that time, I have gathered enough material on some species to give them their own page. So...here are the Bitterns. The latest observations are at the top, and
scrolling down will send you back in time--to the earliest one in 2002.

03/03/2024  Brazos Bend State Park  I was near the pod of baby alligators south of the Spillway Trail (that I had been watching since the summer before),
 when I heard an American Bittern (Botaurus lentiginosus) call from right behind me-on the North Side of the trail. It only called once, but the call was easy to recognize. After 
a careful search,  I found the Bittern hiding among a small clump of Giant Cutgrass.  It remained hidden, so I went back to observing the pod and discussing it with visitors. 
The Bittern moved until it was a bit easier to see, so I pointed it out to a group of visitors, and did my impression of a Bittern call. My impression wasn't very good, but
illustrated how  weird the call was. I could tell by the quizzical expressions on the faces of some of the visitors. But then, a few minutes later the Bittern actually called--only
 once, but enough for us all to hear it. Over the next few hours, the Bittern moved out of one clump of grass, through some bare scrub, over the old alligator nest mound,
and into another small clump of grass.
   
 
I only have a few images of this Bittern, and no video.  This relatively bare sighting inspired me to revisit some of my old Bittern images and video clips from 2015 (they're
further down on this same page); and  also to do more research about how Bitterns make that odd call.Today's photos also show how the colors of the Bittern work with
various backgrounds as it walked out  of the grass, through other plants, and into another patch of grass. The plants in the area of Pilant Lake from the West bank, and 
along the Spillway Trail East changed a lot when it all dried completely in 2022.  The Giant Cutgrass  (and other plants) that had been there appeared dwindled in the 
dryness in 2022. Spring and Summer of 2023  were almost as bad.  The grass is almost entirely gone from  that area and I believe that the Bitterns no longer find enough
cover (and maybe enough food) to visit there as often as they used to.
   

I've found two sources that gave me some very interesting concepts related to Bitterns and other birds:  #1. " The Function of the Oesophagus in the Bittern's Booming"
by James P. Chapin (1922) and #2. "Coos, booms, and hoots: The evolution of closed-mouth vocal behavior in birds" by Tobias Riede, Chad M. Eliason, Edward H. Miller,
 Franz Goller, and Julia A. Clarke (2016)
(Chapin 1922) described "two curious elongated pads" on the inner surface of the joint of the lower mandible (mandibular rami); and guesses that they may serve as a
plug to keep air in the gullet. They seem to be temporary structures. Just closing a bird's beak alone wouldn't work to keep air in the oesophagus, so the extra pads
would be needed. The conclusion is that the Bittern does inflate its oesphagus, but the process for doing that is unknown.  I made the image below from digital models
of a Eurasian Bittern (Botaurus stellaris) skull and mandible that I placed together, then took a screenshot--which I sketched onto.  The image has the proper attributions for
the models.


(T. Reide et. al. 2016) Discusses more about the mechanisms used in "closed-mouth" vocalization. Most birds call with open beaks. but a few make sounds with their
beaks closed; and use a bladder, or something  resembling an inflated bladder to modulate the sound. Since birds don't have lips, simply closing their beaks won't
produce a good seal. I haven't seen a discussion of how the seals work exactly, but the study indicates that in some species (including Bitterns) the espophagus is inflated.
My video clips demonstrate an American Bittern call. Until I read the T.Reide study, I hadn't realized that other birds I have seen would also use a similar method. I've been
 standing near Emus when they made their low rumble. Doves also inflate their esophagus when they coo. When they exhale, they close the upper throat, inflate the
esophagus then coo by calling through their syrinx and modulating the call using the closed, inflated bladder. Such techniques result in calls with relatively low
 "Fundamental frequency".
After reading all that, I tried to modulate my own voice by making sounds mouth open, mouth closed, puffing cheeks. Putting air into my esophagus just allows me
to burp. I can make an interesting grunt with mouth closed and forcing air "backward" by some kind of throat movement. I can do it, I've never considered
figuring out HOW.  I could produce changes in tone, and also made my dog look at me like I was crazy.

From BBSP on 06/19/2022   The water level drop in Pilant Lake has affected all kinds of things. Least Bitterns-which are usually very shy, and not seen at BBSP very
 often-have been very active.  On some weekends, I have seen up to 6 in a single day.  I believe it's because the water has left from their usual hiding/foraging spots, and they have to hunt
the puddles that remain.  The puddles don't offer much cover (since they are surrounded by open mud), so we get to see more Least Bitterns.
Green Herons have also been more common in Pilant Lake along the Spillway Trail, and probably for the same reason. It's been a great opportunity to witness both species foraging
 side-by-side (or at least within a few yards of each other).
 On 6/16/2022 , there were more Least Bitterns out hunting. As I've mentioned before, sightings of Least Bitterns are relatively uncommon at BBS.  (there are probably many of them out
there, but they are secretive). These were all at Pilant Lake, near the Spillway Trail. They are probably more visible (like many of the other hunters showing up there) because the depleted
 water of Pilant Lake has formed shallow puddles that contain trapped prey. The first 3 images below show one of them at various stages of balance on a branch.  In the fourth, it had
moved to another.         The video is here(mp4).
   

The 4 images below are frames from a video clip of one of them hunting. These 4 show it targeting, then catching, a fish (there's more than that in the video.).  

   

I've captured some high-frame rate video clips of one of the Bitterns hunting, too. The sequence below are frames taken from one of the video clips that was filmed at 480fps. It shows the
 subtle shifts in the Bittern's position as it finds a target, extends its neck toward it, then leans forward with its body to prepare for the thrust forward with its beak. After capturing the fish, it
pulls upward and back, and regains a compact position. Amazing balance!  I've completed the slo-motion video. The HFR video is here(mp4).

   

   

   

Update 06/09/2022 - From BBSP on 06/05/2022   Due to trail construction, lack of rain, and the heat, the water level in Pilant Lake has dropped dramatically over the last month or so.
The first picture, taken near the Observation Tower, shows how far the water has lowered, and the small channel made by drainage.  While the high number of Green Herons was unusual
(well, for me, at least) I was really surprised when I saw at least 4 Least Bitterns! They are usually shy, and I don't see them often. But four of them were hunting near the Spillway Bridge,
along with the Green Herons.
 

03/07/2021   What did I see today? Well, here we go. I passed at least 6 American Bitterns (Botaurus lentiginosus) in the morning. I caught photos as one of them successfully caught 
crawfish, but the lighting was bad.  I always enjoy seeing Bitterns!  The first two images below are shots taken of different Bitterns as they foraged. The third image is a frame from a
video (mp4) showing the Bittern doing a swaying motion.  In this article:
"Kushlan, J. A. 2011. The terminology of courtship, nesting, feeding and maintenance in herons.", it says this: "While Neck Swaying, the neck and sometimes the body is moved from side 
to side, the head tending to be rather stationary.  Neck Swaying while feeding may be a method of enticing small movements of prey, while the heron’s head remains ready to strike. Neck 
Swaying is also used in the Bittern Posture, probably to increase camouflage value."  Since the head doesn't move while the neck and body does, it doesn't make sense that this movement
is to allow perceptive focus for targeting prey. I'd always considered it as a feint that might distract attention from the stationary head just before a strike.   I hadn't considered that the
movement could also serve to startle prey into movement.  There are other head movements that do allow for focusing (from same article: "Head Swaying and Head Bobbing are probably 
used to obtain parallax and gain a more accurate estimate of a prey item's location and distance.")   Finally, here's an alligator helping give extra emphasis to one of our alligator warning signs.  
 
    
           Bittern just looking around.              I really like this one, peaking around a tree..         Looking forward, neck swaying..               Just pay attention to the sign, okay?

04/28/2019   I was near the 40 Acre Lake Observation Tower when I noticed a small, brownish bird landing on the floating vegetation.  A closer look through the binoculars revealed that it was
a Least Bittern (Ixobrychus exilis).  While they do live in Brazos Bend State Park, sightings are relatively rare, since Least Bitterns are usually shy.  Although they resemble the more commonly-
seen American Bittern (Botaurus lentiginosus), they are less than half the length (11 inches for Least; 26 inches for American); and they are colored differently. With the Least having a "dark 
crown and back, with buff-colored wing patches" while the American has a "dark moustachial streak, developed into a black triangular patch on either side of the head...and by it's finely 
spotted and vermiculated upper parts."  (these decriptions are from The Herons Handbook by James Hancock and James Kushlan 1984 pages 236 and 268)
The bittern was about 50 yards from me, so I was able to watch it through the binoculars, and then through the camera for a few minutes.  It foraged a while, and then flew off into cover. 
The two images below were the best I could crop from the long-distance photos.   And, the short video clip showing the bittern hunting is here(mp4).  It was a rare treat to see the bittern at all,
so I'm sharing the video here.
   

01/01/2019   I was hurrying back to the 40 Acre Lake parking lot to meet for a hike, when I noticed this American Bittern (Botaurus lentiginosus)
capture something. I stopped walking and shot video for a few minutes. The Bittern had caught a Lesser Siren (Siren intermedia), and had quite a struggle
with it.  The image below is an image from this video clip(mp4), the video was shot at 60 fps but I've slowed it to 15fps for clarity of movement. After witnessing
the end of the struggle, I really had to hurry to meet up with the hike.

March 22, 2015--(uploaded 3/12/2024)  I watched a Bittern calling and captured detailed video of multiple callls at normal frame rate and at 120 fps. Although the video was interesting,
I hadn't done anything with it until now (2024...9 years later, Wow!).   The Bittern calling video will be here (mp4). The images below are from photographs of the Bittern. I've found two sources 
that gave me some very interesting concepts related to Bitterns and other birds:
#1. " The Function of the Oesophagus in the Bittern's Booming" James P. Chapin (1922) and #2. "Coos, booms, and hoots: The evolution of closed-mouth vocal behavior in birds" by
Tobias Riede, Chad M. Eliason, Edward H. Miller, Franz Goller, and Julia A. Clarke (2016)  
(Chapin 1922) described "two curious elongated pads" on the inner surface of the joint of the lower mandible (mandibular rami); and guesses that they may serve as a plug to 
keep air in the gullet. They seem to be temporary structures. Just closing a bird's beak alone wouldn't work to keep air in the oesophagus, so the extra pads would be needed. 
The conclusion is that the Bittern does inflate its oesphagus, but the process for doing that is unknown. I made the third image below from digital models of a Eurasian Bittern 
(Botaurus stellaris) skull and mandible that I placed together, then took a screenshot--which I drew on.
   

The batch of images below are frame grabs showing a Bittern calling event.  They often start by slapping the beak closed, making a distinct "clack" sound. This might be 
amplified by the expanded throat--expanded by air in the esophagus. As seen in slow-motion, the first beak slaps might include gulps of air being captured into the esophagus.
This is all shown in the video that I edited from captured footage of different calls that day.
    
 
    

The actual "call" follows, with more pronounced head thrust and the "goo-gunk" sound, and much larger bladder expansion.  Along with the sounds-and not visible from this angle
are the flashes of color by expanding the feathers along the neck and throat.
    

February 1,8,15, 2015--Three weekends of Bitternness.... Between the good rains we had from last year, and some from this year, water levels in the park have been the highest in
years. This has evidently been good for the American Bitterns, and they have been active! This is what I was able to see over the last few weeks:
February 1st, I watched a Bittern hunting. I noticed it because of the position of its neck and head. The Bittern's neck was fully extended, and it was focused on something in the plants. (PIC 01)
Then, it slowly moved forward, keeping its head still, but "taking up the slack" of its neck. And when it launched its head forward, it was rewarded with a crawfish. The two pictures show the the
neck fully-extended, and then the crawfish in its beak.(PIC 02) This video clip shows the actual capture and then the removal of one of the crawfish's claws.
The Bittern continued hunting, when another Bittern walked out of the rice, within view of the first Bittern. This newcomer started walking quickly towards the first Bittern. I began filming at 
high-speed, because I expected to see conflict, and I wanted to define how that unfolded. Instead, the Bitterns began a display behavior that I had never seen before. Both of them "bowed" 
bending forward, and then they opened their wings and exposed white patches on their backs.  At that point, they began walking slowly-in a "stalking" manner, showing their backs to each other.
After a few minutes of this circling, they moved away from each other. They made no sound. This interaction amazed me, and I tried to catch everything I could with my camera--but I didn't want
to risk changing any settings or risk looking away. The Bitterns were only about 10 yards away and I didn't want them to notice me. Still, I thought the footage and images I caught were amazing.
Photos and framegrabs from the video are PIC 03, PIC 04, PIC 05.    The Bittern catching the crawfish video is here (mp4) .      The Bittern conflict video is here (mp4) .

     
                           PIC  01                                                                            PIC  02                                                                    PIC  03                                                                  PIC  04

                           PIC  05
On February 8th, I was at the same part of the 40 Acre Lake trail. There, I watched a Bittern as it hunted. After a while, it went to a small "nook" in the wild rice, faced the rice, and began 
swaying. I thought this this might meanthat it would begin "booming", and it appeared to start to call, but I couldn't be sure because of the wind blowing.  Just a few minutes later, another 
Bittern flew out of the rice, and landed a few yards from where the first Bitternwas standing.  It appeared to start into the rice, and I began filming. And, I was treated to ANOTHER 
territorial display. This confrontation lasted for about 5 minutes, and finally ended with the first Bittern having moved off, and the "newcomer" standing in the same spot where the first 
Bittern had been standing, and almost in the same position! After a few minutes, the "newcomer" turned, and began hunting. After about 10 minutes, it caught a crawfish. When it began
to eat it, the "first" Bittern came rushing back, from some yards away, in a major aggressive display. After more confrontation, the Bitterns seem to arrive at a sort of truce, and they passed
each other, though keeping their distance, and continued hunting.  I filmed most of this. I extracted some frames from these clips video, and images below are some of those frame-grabs. 
 In 2021 I've put the video clips of from this together into one large file.  
I have never seen any behavior like this between Bitterns. I have found a few references to it.  In my copy of The Herons Handbook by John Hancock and James Kushlan there is reference
(on page 271) to a description of behavior in 1911. This description can be found online 
(look for "Concerning the Nuptial Plumes Worn by Certain Bitterns and the Manner in Which They Are Displayed" by William Brewster). I also found some interesting
descriptions here:
https://johncpitcherart.wordpress.com/2014/04/26/american-bittern-behavior-sketches/

      
                                             PIC  06                                                                                                  PIC  07                                                                                               PIC  08 
      
                                             PIC  09                                                                                                  PIC  10                                                                                               PIC  11
      
                                             PIC  12                                                                                                  PIC  13                                                                                                      

On February 15th, I was at the 40 Acre Lake parking lot. I was going to look for the Great Horned Owl nest, when I could hear Bitterns calling out somewhere over the lake. So, I walked down to
40 Acre lake. I could hear the distinct call of Bitterns, but they were hiding in the rice.  As I was moving east, towards the Observation Tower, I heard the "click, click, click" that signals the start 
of a Bittern call. I looked left, and saw a Bittern calling! And I stayed and waited to see if it would happen again. And it did call again--and finally, after years of watching, I was able to see and 
hear a Bittern calling quite close, and shot some video.  Bitterns have a very distinctive call. The three images below are framegrabs of  one of the calls.  The video clip showing 2 different 
calls is here:   Bittern Calling (mp4) .

      
                                             PIC  14                                                                                                  PIC  15                                                                                               PIC  16

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                                                                                                                                                                               BEFORE CATCHING FISH

The picture bottom right is a frame grab from the video that I've put together from clips I filmed of the Least Bittern as it hunted. I filmed at 30 and 120 fps. To see the video, click  here. 

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                               GULP!                                                        RICKUBISCAM 01/25/09

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                    HERE HE COMES                                                            BEEP-BEEP!                                                          MADE IT!                                             CAN YOU SEE ME NOW?

  March 02, 2003
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                                   TICK                                                                             GLOOP1                                                                          GLOOP2
I was talking to some park visitors when we here this really odd sound.  Everyone got quiet, and someone asked "What the heck was that?" I heard it again, and I guessed that it was an American Bittern,
but I'd never heard one before. However, Donna (she knows who she is) had described it to me, and she'd hit it right on the money. After a little search, I found it. The pictures above and below (starting 
with TICK, and through  GLOOP3) show frames from a movie clip that I was able to capture with the Olympus C-700.  The captions are how I would describe the sounds I heard him making. Gloop 1-3 are
three stages of a single deep sound.   Of course, I'd only intended a quick trip, so didn't bring my video camera.  Click the following links for two flv video clips of the Bittern calling clip1(656 kb)  clip2(654 kb).
He was about 30 yards away, and blends in with the grasses, so the resolution isn't that good. I've also included an .mpg (2,619 kb) file of the second clip that's a little clearer (but much larger!). One never
knows what one will see at this park. The last image (AMERICAN BITTERN) is a little better photo I was able to get as he was walking. 

UPDATE, 01/04/2014: In an effort to update the pages to be better visible with today's (2014) internet speeds; I have been expanding the sizes of the pages. Along with this, I will try to post better 
(upgraded) video clips whenever possible.  Unfortunately I will not have the original video files for some of these. For others, I will only have the digital video that I shot at the time. If I can, I will "remaster" 
these video clips to a larger size. Here are the two video clips referred to above,
remastered to a somewhat larger size (480 x 360).   clip 1 (wmv 3.1mb)  clip 1 (mp4 3.9mb)   ; clip 2 (wmv 3.0mb)  clip 2 (mp4 3.8mb)

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                                    GLOOP 3                                                          AMERICAN BITTERN

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                       AMERICAN BITTERN 1---                                     --- AMERICAN BITTERN 2---                                           ----- AMERICAN BITTERN 3-     ---- 

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                          AMERICAN BITTERN 4 ---                                  -AMERICAN BITTERN 5 

The images above (bittern) show an American Bittern, which is usually a shy bird, and rarely seen. I think part of the reason for this is its amazing camouflage. I was taking pictures of this one, 
and trying to show it to some park visitors and they had a hard time seeing it. Click here(mpg 1,681 kb)  to see a short movie of this bird, and you'll see what I mean.

If you'd like to know more about the park follow these links:

Brazos Bend State Park   The main page.

Brazos Bend State Park Volunteer's Page  The volunteer's main page.
 

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