Limpkins! (Aramus guarauna)
This page started 04/01/2022 from material I posted earlier on other pages.  Rickubis designed it.  (such as it is.) Last update: 11/15/2024
Images and contents on this page copyright ©2021- 2024  Richard M. Dashnau

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I was introduced to Limpkins when I heard about their appearance at Brazos Bend State Park. I learned that they probably followed the invasion of Apple Snails (Pomacea sp.)
across the Southwest states until they appeared in Texas. I learned about and saw Apple Snails first, and the information I've gathered about them is on my Snails Page. I've
learned that although the circumstances which brought the Limpkins here isn't so good (invasive snails), the fact that we can watch them in different places, here in Texas, is 
really amazing.  It appears the Limpkins have only been here a few years so far. So, I'm collecting my images/videos here so others can see them. The latest additions will
be at the top of the page.

11/03/2024   At BBSP, while walking on the Spillway Bridge around 8:30am; I'd been hearing Limpkins calling to the South. But they were far away, and out of sight. I'd stopped
 on the bridge to just look around. The view to the South now shows parts of the "mile stretch" section of the road--which hadn't been visible until recently. After seeing a
Spoonbill. I finally found one of the Limpkins about 40 minutes later. I was still on the bridge, because it was a nice morning. The Limpkin was even further away than the
Spoonbill was. But I tried some photos for that, too. It was to my left, or Southeast of my position, at 9am. I was looking almost towards the Sun, and it brightened the outline
of the Limpkin. This was just the second weekend that I'd heard Limpkins in the park after a year or  so. The last 3 summers have been brutally dry. Hurricane Beryl and the
rain a week after helped  replenish some of the water we needed. The presence of the Limpkins was a  good sign.


03/19/2023 A cold front had passed through recently. That morning, the thermometer in my car showed 47°F. I didn't bother trying to record  the air temperature on the trail because I was
trying a new piece of equipment that I thought would give me related data.  I can say that it felt REALLY cold out there.  Limpkins were first reported in Texas in 2021. They've been hunting
in Brazos Bend State Park since then, usually around Live Oak Trail (and the property next door) during the Summer.   When Live Oak Trail dried out last year, the Limpkins stayed near the
lake next door to BBSP, but a few foraged in Elm Lake.-which is about 1/2 mile from where the Limpkins were on Live Oak  Trail. I've watched them in this corner of the lake, and found out
they were eating mussels.
   

Limpkins are "mollusk specialists", and are adept at opening many types of shells. I was happy the first time I got to see a Limpkin eat a mussel a few weeks ago. On this day,  I watched this
Limpkin capture at least 6 mussels over 45 minutes, and was able catch some of that on video. That's what will show here.  The  Limpkin was hunting along the near bank of  that island across
the way (about 50  yards from this trail). When the Limpkins hunted along Live Oak Trail, they probed with their beaks, similar to the way Ibises do.  It seemed to be mostly blind probing in 
murky water with dense vegetation. But this one seemed to be hunting with its eyes, visually inspecting the water, similar  to Herons  or Egrets. the frequent probing at Live Oak Trail.  Pictures
and video clips of the Limpkins on Live Oak Trail are on further down on this page.
   

 I caught multiple videos of the entire process-from capture to cleaning the last morsels out of the shell. The procedure as I saw it: 1)Hammering at the mussel-this seems to  be aimed at the
outer edges of the  closed shell, possibly to chip off the edge so the beak can be pushed in. 2)Standing the shell and trying to push the beak between the halves. 3) Once part of the beak is in,
move it around to disrupt the mussel until both jaws get in so that the shell-closing muscles can be cut. 4) Now the mussel shell lies open. Time  to snip the good parts away from the shell. 
Small bits are pulled from the shell and tossed, although a few are swallowed. 5) The main body is pulled out, shaken a bit, then swallowed without ceremony.  6) A bit more cleanup of the shell
and surrounding to pick up any missed scraps, and then off to hunt for the next one.  Someday I might pull frames from the video to illustrate that procedure here, but not today.  For now, it's 
visible in the edited video.  By the way, note all of the discarded mussel shells in a few of the pictures below. Wow!  So, even though the day was cold, damp, gray and pretty miserable-it was
worth going out on the trails that day.
   


On 01/15/2023  I was at BBSP, and it was an interesting day. Herons and limpkins!  At 11:00, one of the park visitors pointed out that a Limpkin (Aramus guarauna) was foraging near an
island in Elm Lake.  I'd have never noticed it otherwise, since a group of Black-bellied Whistling Ducks were lying around and swimming there, and the Limpkin was among them.
   

The Limpkins had been hunting along Live Oak Trail through 2021 and 2022. They seemed to leave that area during drought in the Summer of 2022, and one was seen briefly in Elm Lake then.
I was happy to see this one, and wondered if it would get lucky, since they prefer to eat molluscs.  The Limpkins have moved into Texas because of large numbers of Apple Snails (Pomacea sp.)
that have appeared here. To our knowledge, there are still no Apple Snails in Elm Lake (no egg cases visible).  But the one seen in Elm Lake in 2022 was eating mussels. And...this Limpkin
found a freshwater mussel, too!
   

The Limpkin's meal remained partially hidden by a bump in the ground. I was happy to see the process anyway. The images below are frames from video.  The edited video is here .
  

From BBSP on 05/29/2022   For now, more Limpkins.   As usual, lots of things were going on out at the park. I spent about an hour on Live Oak trail, and watched
the Limpkins. Conditions along that trail have been getting dry over the last few weeks, so the Limpkins were foraging at least 25 yards away from me--although they were North of the
trail.  That is, between Live Oak Trail and the Park Road.  This video link will let the viewer spend about 4 minutes with some of the Limpkins I saw.
   

As noted elsewhere on my pages, during dry times Apple Snails (Pomacea sp.) can aestivate by burrowin into the mud. One study showed that they could live that way for 10 months.
 One of the snails that was retrieved by a Limpkin was covered with mud (I didn't recognize it was a snail at first).  Perhaps it had been trying to burrow. No--not the one in the image below.
 

 On 4/10/2022, I'd signed up to lead a hike and other tasks, so I went out to LIve Oak Trail early to look for Limpkins. I got to watch some, and here are
the images. I still haven't caught close shots of Limpkins dissecting snails, but there is some of that shown at distance in the video I got. There are also a few closeups of the Limpkins'--and
Ibis'--dipping behavior while foraging. I believe that "dissection" is an appropriate term for what the Limpkin is doing to the snail. When viewed in realtime, movements are so quick, that
the quick twisting and flicking doesn't reveal what is happening. But if the video is slowed down, then it's possible to see that the Limpkin is using its beak with precision, and is tweezing  
away small bits of snail flesh, and then tossing them aside. In the slowed video, some of the bits are visible, and some may be pink. I believe that the Limpkin is rejecting bits based on how
they taste. In the video I captured, bits were snipped and tossed...until one bit was pulled off and eaten. The rest of the carcass was eaten right after that. The edited video is at this link. 
Also, if pictures of one Limpkin is good--then a picture of two Limpkins must be better! So, they're here, too.
   

Many folks describe a Limpkin as being about the size of an Ibis. Today, a White Ibis (Eudocimus albus) foraged next to a LImpkin, so I got some direct comparisons. The two birds foraged
next to each other, and I could watch them both probing for food with their beaks.  Clips of them foraging together are also in the edited video.
   

From BBSP on 04/03/2022. More with the Limpkins! I was on Live Oak trail around 8:30am. There weren't very many Limpkins active there yet, but I did see a few.
One was calling from a tree across the lake that is outside the Southern boundary of BBSP. I shot video of that to show how far that sound carries. About 30 minutes later, The Sun started
breaking through the clouds,  and more Limpkins began hunting North of the trail. I was briefly distracted by watching a Great Blue Heron hunting successfully, but returned to the Limpkins
for these images and video.  The images below are a mixture of still photos and frame grabs from the video clips.  The video clip is here.
   

I was able to get some nice close views of Limpkins hunting, but a clear view of the Limpkins breaking into the snail still eluded me.  I also found this report on line:
"Natural selection by avian predators on size and color of a freshwater snail (Pomacea Jagellata)" 1999 by Wendy L. Reed and Fredric J. Janzen.  The research was done in Costa Rica,
but involved Snail Kites and Limpkins. The predation was on Apple Snails, but a different species. Size and behavior of the snails seems to be the same as our problem P. maculata though.
Among points in the report I found interesting: 1)  Snail kites rely  on visual cues while hunting  by flying slowly across a marsh or hovering while searching for snails. Limpkins rely on tactile cues
 during foraging by probing beneath vegetation and on the bottoms of marshes for apple snails. 2) Individual Limpkins differed in the size of snails they consumed, and in their choosing to
puncture shells before consuming snails.  No single foraging pattern is exhibited by all Limpkins in this study area. 3) As snails age and grow, they change their vertical distribution their primary
behavioral defense against predators. Large apple snails spend more time at the water's surface. The change in size is accompanied by changes in behavior.  Larger snails respond to
mechanical disturbances by dropping off vegetation and burying themselves in the substrate quicker than small snails do.  4) Limpkins may prefer snails  of average size due to decreasing
energy gains at either end of the snail size distribution. Limpkins were more likely to puncture shells of large snails compared shells of small snails. This shell-puncturing behavior suggests
that large snails may be more difficult to handle, requiring additional time and energy to puncture the shell and obtain a meal. The optimal prey size for Limpkins might then be those snails small
 enough not to require a hole to procure a meal, but large enough to provide a worthwhile effort.
The report added a bit more perspective to some of behavior I've recorded.  I can see how a Limpkin might have a harder time "pincering" a large snail in its beak and carrying it, so puncturing
it would make it easier to carry. But I've seen that the Limpkins have carried the shell out of the water and to a solid base to give support the snail shell during the stabbing attack. I think piercing
the snail weakens it and the muscles holding the operculum closed, and allows the Limpkin to get under that "trap door" to tear it off.  In one of the other clips from this day, I show what happens
with a really small snail  (three images below right).  The Limpkin set it down, prodded it a bit (and it was too small to get a beak tip into) then tried to smash the snail with the tip of its beak. The
snail was knocked into the air and fell in the water and was lost to the Limpkin.
   
                                                                                                                                                      
A bit later, the Limpkin found a larger snail. The snail was carried to a more solid platform. . 
   

I could see the Limpkin working on the hidden snail. It alternated delicate probing with hard stabbing.  Movements changed as the snail's body was exposed. There was vigorous rapid movenents
of the beak as the snail body was pulled free. Viewed in realtime, the movements are very quick, and barely noticeable, but with slowed down video, the amount of movement is impressive.
What was being shaken free?  Was it shell fragments, detritus, maybe the toxic yolk glands? I can't identify the fragment the seemed to fly off the snail as it was being shaken.. The Limpkin
didn't immediately swallow the snail either. It tossed the meat to the back of its beak, seemed about to swallow--then spit it up and shook it a few more times before swallowing it. Finally, I
caught a quick view of a Nutria "photo bombing" the scene.  Again, The video clip is here.   
   

Update 04/01/2022 - From BBSP on 03/27/2022. I'd last seen Limpkins on Live Oak trail last October (2021). Since then, less Apple Snails (Pomacea maculata) and egg masses were
observed on or near the trail.  Over the winter, no snail eggs appeared on Live Oak Trail so I stopped going there because I thought the Limpkins wouldn't be active. Sometimes I could
still hear Limpkins calling from this area even while I was at 40  Acre Lake.     The lake just across the South park boundary contains the main snail infestation.  With the warmer weather,
 I checked the trail for snail eggs. No egg masses yet, but the Limpkins were around.  Two Limpkins were resting on top of the floating plant mats about 40 yards away, along with a few
scattered snail shells. I watched another one as it hunted.  This was the first time I got to see the Limpkins foraging! Widely-splayed toes help distribute the Limpkins' weight as they stride on
floating plants.  Their constant probing for prey reminded me of the similar behavior of Ibises. Success! Jackpot! A big snail was discovered as turtles and I watched. The Limpkin moved to a firm
surface so it could pierce the snail. It placed the snail, then attacked it with short, accurate and powerful strikes. Most of the images here are frames from the video clips I shot.
 The video clip is here.
   

I've tried to pierce Apple Snails by stabbing them with the point of a smooth flounder gig.  The shell is round and hard--and difficult to pierce with a single point. If the point wasn't thrust just right,
it slid off the shell, and the snail rolled away.  But this Limpkin was an expert, and pierced the shell after a handful of hits.  I was not close to the Limpkin, so couldn't get a great view of its technique. 
There's a a bit of manipulation needed to get the snail out of the shell.  It's interesting that the feeding strategy doesn't include shattering the shell into pieces.  There was rapid back and forth
head-twisting motion, just before the snail is taken out. And then the end of an invasive snail.
   
                                                                                                                                                      
Even with wide feet, the Limpkin was too heavy for some plant mats. It continued working as it sank into the water, then hopped to the next mat.  I saw this Limpkin eat at least 5 snails in 30
minutes.  The probing seems to be random. How can a Limpkin tell when it has found a snail? It must be contacting other hidden objects, sticks, etc., with its beak.  But it seemed to ignore
them in these very quick contact probes.  But with positive snail contact, the Limpkin starts working at the snail.  One snail took more effort, and the Limpkin had to do a lot of twisting to get it
out of the plants. What was the snail holding on to?  The Limpkin seemed to be a bit surprised,. Again, The video clip is here.
   

The egg masses  of Apple Snails (Pomacea sp.) are toxic. The glands that provision the snail eggs (albumin glands) inside the snail are also toxic.(more details are on my Pomacea Page).
There are multiple reports that describe how the snails' predators discard these glands. ( since Oct. 2021 I've found more reports that describe this behavior) Discarded glands have been
seen in snail detritus left by Raccoons. (Observations of Raccoon (Procyon lotor) Predation on the Invasive Maculata Apple Snail (Pomacea maculata) in Southern Louisiana  by J. Carter et. al (page N15.)
Removal of these glands by Limpkins is mentioned in " Defenses of the Florida Apple Snail Pomacea paludosa by Noel F. R. Snyder and Helen A. Snyder (1971)(page 177)" and  by Snail Kites in
"Mollusk Predation by Snail Kites in Columbia  Noel F. R. Snyder and Herbert W. Kale"  1982  (page 97)
 Nothing pink showed in the meals I watched, but that is inconclusive.  They could have been hidden inside the body.  I took the last  picture on Live Oak trail in 2021. The shell shows twin punctures,
which are evidence of Limpkin predation. The pink mass above the shell is a discarded albumin gland.  I hope to catch this behavior on film.
The snails are still here in the park. It was great to finally see Limpkins hunting; but bad  news that there are so many snails inside BBSP.     
   

Update 04/04/2022 - From BBSP on 10/24/2021. On Live Oak trail October 2021. I was still trying to see more Limpkins, and hoped to see them foraging. I also hoped to see any other
animals-Alligators, or Raccoons-going after the Apple Snails, but no luck there.  I did see and hear this Limpkin, and the call was not the "crying" sound that I'd hear before. I recorded the call.
Since then, I've learned that Limpkins have different calls (like other birds do) and this was probably a female Limpkin.  I got the call on video, and  The video clip is here.
   


   

07/25/2021 and 08/01/21- I've been doing more research on our apple snail invaders since July. When I saw the inside of an adult Pomacea, I noticed orange masses or organs.
I figured that those were eggs. Since the deposited egg masses are toxic, I wondered if the eggs inside the snail were also toxic. And, if the eggs are toxic--how can any animals
--such as Limpkins--eat the adult snails?  After a lot of searching, I couldn't find any detailed description of how this situation is dealt with.  The first picture below was
taken on 7/24/21, but I'd seen inside other snails before then.  The other two pictures were taken 7/10/21, and show a snail that something had eaten. At the time, I hadn't
realized that the toxic egg masses had been left inside the shell.
   

I found a number of references saying that animals that eat the snails discard the albumen glands. But the only predator I saw named doing this was Snail Kites. But no clear descriptions.
I started searching for proof that Limpkins might discard these organs. I found a video on youtube that shows a Limpkin doing this!  After that, I started looking around BBSP for signs
of this behavior.
But let's pause a bit.  Limpkins?  Limpkins (Aramus guarauna) are long-necked wading birds with long, pointed beaks. They're about the size of Night Herons (maybe a bit larger).
According to Avibase, the World Bird Database, it is the only extant species in the genus Aramus and the family Aramidae. The "home range" of 4 subspecies of Limpkins is: Florida, Cuba,
 Jamaica ;  southern Mexico south to western Panama; Hispaniola and Puerto Rico; central and eastern Panama; South America, south west of the Andes to western Ecuador, and east of the Andes
south to northern Argentina. Like many wading birds, Limpkins can be generalist predators but according to many sources, the greatest component of their diet is:  Apple Snails. If we examine the
list of regions  in their "home range", we can see something missing-- TEXAS.  That's right.   In fact, their home range is far from Texas. 
Texas is now being invaded by Apple Snails.  If only Limpkins were in Texas!  Well...they ARE in Texas. In fact, they have been hanging around in the lake next door to BBSP for some months now. 
That lake is infested with snails. Unfortunately, the snails have made their way to the BBSP side of the fence, along Live Oak Trail. But the Limpkins have been picking them off there, also. 
Discarded snail shells litter the trail. I went down Live Oak Trail on 7/18, and I saw something interesting among some discarded shells. I took a few pictures. Next to one
of the shells is a pink mass. I think that mass is one of the "albumen glands" that was discarded by the Limpkin that ate that snail. The trail was really wet, so I didn't go further.
First 3 images below show shells on the trail, and a pink mass neer them. The last image was taken there on 8/1/21, and shows pink material in the discarded shell.
  

I returned to Live Oak Trail the next week (7/25).  I'd been around the other trails, and entered Live Oak from the East end and walked West.  I was doing snail egg removal. It was Noon,
and it was hot, so I didn't expect to see anything.  A Limpkin appeared on the South side of the trail, near the fence, and hunted the area near the fence.  I stayed back, and hardly moved. 
It came to the trail, walked on it a bit, then went back under the fence and eventually up the levee and across.  I got pictures and a bit of video!  This is all edited into this video.
  

Next weekend (8./01). I'd been out on the other trails first. I met a couple park visitors I'd sent to Live Oak trail and they told me they'd hadn't seen any Limpkins, but had seen snail egg masses,
 and even a few live snails. So I was on Live Oak Trail again, at about 12:30pm.  I'd gotten almost to one of the "bridges" when I saw a Limpkin up in a tree between the trail and the
road--that is, North of the trail. I watched it for about 20 minutes, until thunder from approaching rain clouds convinced me to start back to my car.  I got a brief look at another Limpkin
in a tree near the one I'd been watching.  They both moved, and seemed to start hunting, but I didn't want to get caught in rain that seemed to be approaching. I got photos and video
clips.  Again, this has all been edited into this video.
   

And, I found another snail shell that seemed to have remnants of a discarded "albumen gland" in it.  I also found another paper that seems to have been inspired by the habit of snail predators
discarding the "albumen gland":  "Apple Snail Perivitellin Precursor Properties Help Explain Predators’ Feeding Behavior" 2016 by Cadierno, Dreon, Heras. While it discusses Pomacea canaliculata and
 not our problem (P. maculata), I think it's still related. This study is where I got the term "albumen gland" for the organ which produces the snail eggs. Perivitellin serves as a nutrition source for snail
 embryos (similar function to egg yolk ). While the paper is a bit technical for me to fully understand, for me it verified:   a) that the organs are toxic, and therefore consumption of the entire snail
could be dangerous;  b) that experienced predators do discard toxic parts of the snail, rendering it safe to eat. From the paper: " Therefore, as the noxious perivitellin precursors are exclusively
confined within the AG, this explains why it is the only usually discarded organ, even when this behavior implies a large loss of the total energy and nutrients available from the soft-body biomass
(Estoy et al. 2002). Finally, we propose that the reddish-pink gland color may contribute to this behavior, helping the visual-hunting predators of adult snails to associate the bright AG color with the
noxious compounds it carries."(page 466 "AG"=albumen gland)  This could be trouble for our local predators (such as alligators) that might consume entire snails.  Raccoons might be able to identify
and remove the glands, but they'd have to learn about the danger first (that might be what ate the snail in the picture above). It's potentially good news that Limpkins are eating snails here. It will
be better news if they establish a breeding population in Texas. They can help control the spread of the Pomacea. But, regardless of predation, and it seems to me that the snails will remain.  I think
the most we can hope for is that the predators that have followed the snails (and other local predators) and the snails will reach a "balance" where the snails will not overpower the environment.
There must be reasons why Limpkins haven't made the journey here before.   If lack of snails was a factor...where they're here now. But, if there are other environmental reasons (such as temperature)
 the Limpkins may not stay.  I hope they do.

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