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08/15/2021- I was near the Observation Tower at 40Acre lake, when a visitor said she'd seen a snake go after a frog. The frog got away,
and I was able to get a quick look at the snake through my binoculars. It was a Broadbanded Watersnake (Nerodia fasciata). It moved away before
I could point a camera at it.  Then I noticed a group of small frogs about 15 yards away, on the surface of the lake. As can be seen in the photos
of the alligator nests and the frogs, the lake on this side was covered with a mixture of plant matter. The small frogs were resting on that.

   
             Frogs are out there!                                   Zooming in to see the frogs.                                           There are the frogs!

When I looked closer, I could see part of the reason the frogs were gathered there. There were lots of flies there--buzzing around the frogs
and landing near them. I didn't see any flies get eaten; but the little frogs looked like they'd eaten a lot already. I've tried to identify the frogs.
Both American Bullfrogs (Lithobates catasbaeiana) and Bronze Frogs (Lithobates clamitans) live in the park. Although I've heard the calls of both frogs-
bull-fiddle "rum-ur-rum"sound for Bullfrogs; single-plucked banjo notes for Bronze Frogs-I can't recall ever seeing any adult Bronze frogs, but I've seen
many Bullfrogs.  Bullfrogs have a "ridge"or "fold" that curls behind their eyes and down around the ear. Bronze frogs have a "ridge" or "fold" that runs
at the edge of their back, from head towards hindquarters. I think I can see the ear ridge on a few of these frogs (not easy to do, since they all seem to
be facing me), so at least a few of them are probably Bullfrogs. I also shot a bit of video so we can all share some time with this group.

  
                                                     Wide shot of the group.                                                                        Cropped view of that shot.

   
           Wide shot of the group.                                                                                      Cropped view of that shot.

02/20/2021  A few days after the Big February Freeze of Texas, I was out at Fiorenza Park North again. On the same morning, I looked near the bridge and was very
surprised to see a Bullfrog (Lithobates cataesbiana) in the water.  Then, I noticed it wasn't just a single frog, but a stack of them! And, they were alive!  Now, this was
just a few days after our major freeze, and large amphibians
were the last thing I expected to see. In fact, I'd gone out that day expecting to see dead armored catfish--and I didn't see any of those. I'd seen an armored
catfish mass-death at that park in 2018. I have pictures on my page here.    Anyway, I was curious about this, and I could not find anything online, or in my limited
library, that described why the frogs were doing what they were doing.  I was also curious about how the water temperature might have been a factor in their behavior
and in the lack of dead fish. I found temperature data for that week at three different websites, and I graphed them.  This is air temperature, of course, so I
am not sure how quickly these temperatures would change that of the water.  The graph is the first image below. I suspect one of the lines of data ended near 18F when it lost
power (like a lot of the area did).  The images below show the frogs. I noted that they were against the concrete, and in the direct sunlight. I assumed that they were
trying to absorb heat.  The "stack" was interesting. The extremely dark color of their skin seemed wrong. It could be temporary adaptation for the cold (for better absorption
of infrared).  I couldn't find information about it.
    
   Temperature data for the week before.      There were 5 or 6 frogs down there.                        There's at least one in the grass alone in front of the stack.

From what I can see in the pictures, the "stacked" frogs are males (the ear is larger than the eye). The one that was floating alone in the water seemed to be dead.  I did not
bother any of the frogs, or get too close...so I did not check.  I was reluctant to bother the frogs because I figured that the frogs had just survived the same freezing
event that we all had.  Bullfrogs live in the Northeast U.S., so the species can survive what I call "true winter" (it's cold enough for long enough to freeze the qround to some depth,
and to form thick ice over bodies of water).  But here, such conditions are rare, so I assumed that the frogs were doing their best to recover from a rare disaster. This meant that they were in the
spot and position they needed to be for the best thermal yield. I was concerned that anything that moved them would atdd more physical stress. So, I left them alone. I was concerned
that some other person might bother or take them (since I had found them)--but I had to leave the frogs in place. 
I went back on 2/23/2021!  The frogs were not where I'd seen them 3 days before, of course.   But after a short while, I found them again.  This time, they were hiding under better
cover, in the shade of some trees.  I was happy to see they were still alive.  So, I took a few more pictures (the last 3 below) before leaving them alone before someone
else saw me watching the frogs.

    
   3 in the stack, one to the left.                       One under a tree a few days later.                  Looks like 3 more under the tree.          The lighting was tricky, but here's one.

05/07/2017 Bullfrog calling...revisited    Last year,  I discovered that male bullfrogs' ears are twice as large as the females' not to hear better than the females. Instead, the large ear helps increase the power
of the bullfrog's call. That is, the large ears don't help them hear better....the large ears help them sound better!  Since then, I've been trying to get better video of male bullfrogs calling. I have finally captured
some video at 480 frames per second (FPS).  The video clearly shows the movement of the ear membranes.

   
The two images below are frame grabs from one of the video clips. The images show one ear membrane distended, and then collapsed. The video is at this link (wmv) and this link (mp4)

  

4/10/2016 Bullfrogs have been calling in the park. I'm a little ashamed to say that up until now, I'd never considered taking a close look at what they are actually doing. Bullfrogs are usually a bit 
shy, and tend to call from cover--or, they'll stop calling and jump away before they can be seen. For the last few weeks the Bullfrogs have been calling along the Spillway Trail, and have been 
easy to see in the corner of Pilant Lake near the Elm Lake water station. With all that "talking" going on, I was able to get a very good short video clip of a bullfrog calling, along with that odd 
"poot" sound that they sometimes make. I wondered about that sound, and scanned the Internet for some hint about how or why it happens.  I discovered some interesting things about 
bullfrogs and their calls.  Bullfrogs actually make a number of different sounds. Males usually do the calling, though females may vocalize occasionally.  The most common is called an 
"advertisement call".  That's the loud "Ruh AMH", or "Jug o RUM"  call. The less-impressive "poot" noise is an "encounter call", or "territorial sound", and is made to warn off or challenge other
male frogs that have wandered into a frog's territory.  One study shows that male frogs respond more often to frogs calling from further away than to those closest--possibly since they already 
know where the nearest males already are, and therefore their territories. Also,in a particular area, different frogs will start the chorus on different days. They sort of..."take turns". And, since 
calling is an "advertisement", it draws attention to the caller--and this includes territorial aggression by other frogs. Some male frogs avoid this aggression by a behavior called "satelliting".
The "satellite" frogs remain quiet during the advertisement chorus, although they know where the calling males are. When a female is drawn to one of the advertisers, the "satellite" frog
intercepts and mounts it before it can get to the calling male. Pretty sneaky, eh?  The study is referred to on this page.  But wait...things get a bit stranger.
The ears on male Bullfrog ears are about twice as big as the ears on female Bullfrogs. A Bullfrog's ear can be identified by the big circles just behind the eyes. Those circles are actually 
membranes (tympanic membranes) which work like our eardrums. Vibrations through the air (sound) cause the membraned to vibrate, and that vibration is transmitted internally by mechanical
linkages to the organs that change it to nervous impulses. Previously, I'd read somewhere that the males' ears were bigger to give them better hearing during mating communication. But 
apparently that's not the case. In this study: ("Function of the sexually dimorphic ear of the American bullfrog, Rana catesbeiana:brief review and new insight", by Y. L. Werner, J. Pylka, H. 
Schneider, M. Seifan, W. Walkowiak and U. Werner-Reiss; I found it at this link) they find that although the male membrane is larger, there are some aspects of the anatomy of the male ears
that offsets the larger membrane size. For example there is a cartilaginous pad in the middle of the ear where the sensor bone structure rests on the membrane (it's the dark center of the ear
membrane).  On male frogs, this pad is thicker--which offsets any advantage from the larger membrane surface. After experimentation, the function of the male and female bullfrog ears was found to 
be not very different at all. So if the larger male bullfrog ear doesn't make it hear better than the female; WHY would it be that way? How could it benefit the male bullfrogs? 
This paper may have an answer: ("Tympanic sound radiation in the bullfrog Rana catesbeiana", by A. P. Purgue.)  The abstract is here. The experiments and results seem to show that as the
frog calls, the ear membrane vibrates and helps add power to the call. The larger ear helps the call by adding about 20 dB (decibels) at the "dominant frequency" of the call (about 250 Hz range)
and adding about 60 dB at the high-frequency part of the call (about 1000 Hz). The bullfrogs may be "calling" with their EARS!  After I'd learned this, I intended to shoot more video of bullfrogs 
calling (my camera has the reach) to see if I can catch this vibration-but the park is currently flooded. However, when I examined my video wmv (my video mp4 ), which I shot on 4/10/16, I found 
that it's possible to see the vibration. The video clip (my video mp4 )is short, and I've cropped and slowed down the area of the eardrum to show it better.  It looks like it's moving! That is amazing.

 

August 09, 2015  Bullfrogs are active around the park, although they were not calling this morning as they have been over the last few weekends. While I was walking West on the Spillway trail
(on my way back to the Nature Center to work a shift) I noticed one Bullfrog seemed to be watching something. It's hard to explain why this frog caught my attention, but I knew that something 
was up. This could be partly due to my experiences with the Bullfrog I'd kept as a pet for quite a while long ago. I used to watch it hunt in its terrarium home.  Anyway, I had just enough time to
start filming him with high-speed video. I didn't want to move closer and possibly scare him, so I stayed back where I was.  The sequence of pictures below are frames from the video clip. 
The video clip (filmed at 210 FPS) is  here (wmv).  I shot the RICKUBISCAM closeup as a photo with a different camera.  The gender of a Bullfrog can be determined by looking at its ear 
membrane (the circle just behind the eye).  If it is smaller-or about the size of the eye, then the frog is female. If the ear is larger than the eye (usually much larger--as in the picture), then the 
frog is a male--at least for Bullfrogs.  Bullfrogs will eat anything they can catch and cram down their throat. This can be worms, insects, crawfish, even smaller frogs. In this case, the prey 
seemed to be a fuzzy, white caterpillar. I'd thought I might be able to identify it later, but there are MANY "fuzzy white caterpillars".  I was happy to be able to catch this frog's leap and slow it down.

IMAGE SEQUENCE OF THE FROG'S LEAP:

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It's not usually obvious, but frogs can turn their heads.  This head-turning is what caught my attention. As the frog focused on its prey, it turned its body ("aimed" its body) by
shifting position of its rear legs. With the prey properly in its sights, the frog "fired" by jumping.

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Now an amphibian missile, the frog flew towards its target. Note the front legs tucked in close to the body. Imagine having to eat by launching yourself, FACE FIRST-at high speed-at
your food. Also consider that this food is alive, and would fight back if it could.

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                                                                                 TONGUE GRAB!
Just before reaching its target, the frog launched its tongue.  What amazing timing this must take! The airborne frog, launched fast enough to fly horizontally, launched its
tongue with enough time to pull it and prey back into its mouth before hitting the water.
A Bullfrog's tongue is attached near the front of it's lower jaw (not near the back, as ours is). Therefore the tongue (which is sticky) flips out, snags prey, and flips it back
towards the frog's throat.  In the second picture above (TONGUE GRAB!), the tongue shows as the pinkish spot just in front of the frog.

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Then the belly-flop landing. With the prey having  been caught, stealth is no longer needed-although this kind of commotion can draw the attention of competing male frogs or ...predators of 
frogs. The front legs have extended, also, and are sometimes used to push struggling prey into its mouth.

01/04/2009--Slow-Motion clip of a Bullfrog leaping out of frame at BBSP.  The video could have been better, but it still shows some interesting things. The frog expelled a string of large
droplets near the top of its leap. It seems to me that the droplets striking the water could be a form of visual (and aural) distraction. Since the stream hits within the flight path of the frog,
watching eyes would be drawn to these splashes, while the camouflaged frog could be lost from view.   Click this link for the video.

 

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                                              HI  DIDDLE DIDDLE AMPHIBIAN BULL FIDDLE
                                                         VIDEO CLIP 4840 kb wmv
A large number of Bullfrogs can be heard in the clip. It is illegal to catch or molest any animal (with the exception of fish) at BBSP. Frogs cannot be legally caught IN ANY WAY at BBSP.  Although fishing is  allowed, State fishing regulations must be followed.  Leave the animals you see at BBSP alone, so that other visitors may enjoy seeing them (and also to avoid being ticketed and fined).

April 27, 2003 I have one more clip to answer a question that many visitors have asked. They keep asking what this loud "jug-o-rum" sound is.  The culprit is the Bullfrog (rana catesbeiana). I've finally been able to get one on video as it's calling(see WHERE'S THE BEER?, below; or see the clip flv video 308 kb ) . Listen to this, and compare to the various alligator bellows on my pages.
   ----------------------------------------------------------
---------------------------WHERE'S THE BEER?

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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