They say pictures never lie but they can certainly give the wrong impression. This American bittern, swallowing a treefrog it just caught, caught it further away from the water but came down to the water, dunked it, and swallowed it. As adults treefrogs often live near water but spend most of their time on land (and more often near the ground rather than in trees). The bittern has covered both its eyes with a nictitating membrane to protect them as it flips the frog down towards its throat.
Bullfrogs hibernate during the winter so their metabolism slows significantly and they aren’t very active but they don’t bury themselves in the mud the way a turtle might. Many bullfrogs at Ridgefield found their hibernation cut short this winter by the herons and egrets and bitterns that worked the shallow channels and ponds of the refuge.
This egret in particular was just walking up and down one such channel, avoiding a great blue heron doing the same, striking at bullfrog after bullfrog, following a familiar process between catching the frog and eating it. First, the frog would be dunked quickly into the water, as shown above. Next, the egret would spin the frog rapidly, presumably causing massive internal injuries to the frog, as shown in the following two pictures. In the first picture, the egret has closed the nictitating membrane in its eyes, a transparent third eyelid that protects the eye from damage while still allowing the egret to see, as water spins off the frog and its clawed feet flail about, while in the second picture the membrane has been retracted.
Then the egret would toss the frog into the air, catching it in a different place on its body, and either repeat the process again if it caught it by a leg, or perhaps crush it in its beak if it caught it by the body. This would happen multiple times until I gather the frog had died or given up fighting, although with the egret constantly keeping the frog moving it was hard to tell exactly when or if the frog itself stopped moving.
The final step was to position the frog head first in its beak and swallow it whole. Bullfrogs are voracious predators and, as they aren’t native to the area, have had a big impact on some of the other small creatures in the ponds and sloughs. However I’ve seen the bullfrogs themselves become prey for the larger predators of the refuge, including not just egrets and herons and bitterns but otters, raccoons, and grebes.
Normally I’m pretty good at spotting bitterns at Ridgefield but I saw them on only three out of ten visits to the refuge over the Christmas break. I worried I was losing my touch until I found this bittern on Christmas Eve slowly working the channel beside Rest Lake. I suspect the real reason I haven’t seen as many this year is that the grasses in this area, normally my best spot for seeing them, have been cut lower in places, eliminating cover for both the bitterns and the animals they are hoping to catch.
The bittern snagged a large bullfrog from the water as you can see in the top picture. In the picture below the bittern has swallowed most of the frog with only the rear feet sticking out of its mouth. The bittern has protected its eyes from the frog’s claws with a nictitating membrane, a common tactic in the chaos of swallowing something that doesn’t want to be swallowed.
In 2001 I bought what at the time was my most expensive lens, Canon’s 100-400mm lens. Since then it’s gone with me on every hike and nearly every trip and been one of my most treasured lenses. However the image stabilization system needs repair but I haven’t sent it in as I was hesitant to spend much money on a lens that could benefit from a modern re-design.
To my great delight, Canon finally brought out a new 100-400 lens and I pre-ordered the day of the announcement. It arrived on Friday so Saturday morning I opened it up and took it to my favorite refuge to try it out. One of the nice new features is that the lens has some weatherproofing, which I got to test with my very first pictures when I encountered this egret in the pouring rain. The egret was on the passenger’s side of the car so I slid over, stuck the lens out the window into the rain, and had just got the exposure and focus set when the egret struck into the water, pulling out this small bullfrog.
I meant to frame a little looser but in my haste to even get the shot I didn’t keep the camera quite level, so I rotated and cropped in post. Still I was pleased that with the zoom I was able to pull back and show a bit of the world these animals live in. The egret with its long featherless legs is built to wade in shallow water like this, able to hunt along the water’s edge, looking for frogs and fish in the water and frogs and voles on the land.
I’ve always loved photographing in the rain, especially to show how animals still have to go out into the rain to live their lives, and I’m thankful my favorite hiking lens now can as well.