Was wondering if any of you might have any thoughts as to this frog activity I noticed yesterday.
In short, yesterday evening along the S shore of Lake Michigan, there were several large frogs, mostly sitting along the edge of the water line.
I walk with my dog along the beach in the Indiana Dunes state park a couple of times a week.
Before yesterday I rarely saw frogs along the beach - maybe one frog every 10 or more walks.
Yesterday I saw at least 15-20 frogs walking maybe 1.5 miles down the beach and back.
These were mostly large frogs - searching on-line leads me to believe they are green frogs.
Most of them were as large as my hand, tho a couple were maybe half that size.
I hadn’t been out there for 7-10 days, so I don’t know if yesterday was unique.
As the season is changing, I wondered if the frogs were somehow preparing for hibernation - or perhaps dying.
If they were going to hibernate, any idea where frogs would hibernate in a Lake as large as Lake Michigan?
The air temp was a tad chilly - maybe 50 degrees.
The frogs seemed in various stages of torpor - a few would pretty actively hop back into the waves when my stupid golden sniffed at them, but others seemed very close to being still.
And none seemed as active as the ones we encountered in the heat of summer.
Most were at the highest point where the waves lapped, but some were higher, where the waves had already receded.
The lake was very rough, but was receded from a previous high water mark.
So, any one have any thoughts as to what was going on other than - of course - the most likely explanation of a plague of frogs?
Next time I head back, I’ll stop at the nature center and see if they have any info, but I figured I’d ask the experts here first.
The semi-aquatic frogs of the Genus Rana, which includes green frogs, bull frogs, leopard frogs and others, hibernate under water, in mud or leaf litter at the bottom of a pond or lake. They get the oxygen they need through their skin.
If the frogs you saw were the size of your hand, they were almost certainly bull frogs, unless you have really small hands.
Before the weather gets really cold to stay, frogs will often spend the night at the bottom and come to the surface during the day to bask and eat, especially if the daytime temperature gets up to 70 F or so. But that doesn’t explain what you saw, because it was much colder. I’m going to guess that the rough water drove them to shore before they were fully dug in for the winter. Had there been a storm?
This is about the only part of your question I can answer. I’m pretty sure they travel upstream in rivers and creeks and find some safe and sheltered spot to hide in.
According to this site, (and the behavior is species specific), most frogs don’t burrow deep into the mud, as they need oxygen even during hibernation. But they can survive freezing much better than other animals.
Well, you know what they say - small hands - - small gloves!
A pretty significant storm system had moved through over the weekend, from the SW to the NE. The activity I described was on a Monday evening. There wasn’t much of a wind at the time, but the waves were about as high as they get absent a HUGE storm. Down here at the tip of the lake it is interesting - feels like stuff ends up here from a long way away.
Looking at this site I’m pretty sure they were green rather than bull. I guess not being terribly familiar with frogs, I may have overestimated the size. Maybe it would be more accurate to say the size of my palm. Looking at the site, the max size surprised me, but the appearance was clearly green.
Do frogs live in large bodies of water like Lake Michigan? I always thought of them as inhabiting streams, ponds, and such. And I always figured the occasional frogs I had seen in the past had lost their way.
The area along the dunes where I was walking is uninterrupted beach, and my understanding is that the lake bottom is pretty featureless - not what I would ( in my ignorance) consider primo froggie real estate. But would you expect green frogs to hibernate in the Lake? Or had these poor guys washed down here from some nice stream up in Michigan or Wisconsin?
I dunno - you are pretty convincing, but I think I’m sticking with my plague theory!
My niece has been studying frogs near lake Michigan as part of her internship, she is near Green bay Wisconsin. I will write her and see if she knows anything.
I took a pic of one, but won’t have a chance to upload it anywhere until this weekend. If someone else was dying to upload it earlier, I could e-mail/text it to a number if you wanted to pm me.
Frogs are more common in smaller bodies of water, ponds, small lake and quiet streams. In big lakes, I would expect that they would spend their time in sheltered coves and stream outlets that had lots of vegetation, water lilies, cattails and such. I would also expect them to hibernate in area where the bottom consisted of really loose, mushy mud or a covering of dead leaves. As Musicat mentioned above, they don’t dig deep, but they need something to visually shield them from predator fish.
I have no experience observing frogs in or near a lake like Lake Michigan; my experience has mostly been in ponds, streams and small man-made lakes. The only two large natural lakes I’ve seen frogs in are Lake Mattamuskeet and Lake Okeechobee, which are very different from Lake Michigan. I’ll be interested to read what HoneyBadgerDC finds out from his/her niece.
Here’s a map or right where I was. (Sorry it is turned 90 degrees.)
I can imagine the weekend rains might have flushed them out of the swamps and bogs via the creek, and then the waves washed them up on the beach to the east of there where I saw them. That’s probably the likeliest explanation - unless they came from further away.
So once they got into the big lake, are they pretty much toast unless they can figure out how to get back someplace more hospitable? They looked mighty exposed, and I figured they’d be an easy source of protein for the gulls you always see along the lake.
Frogs generally prefer to be among vegetation, for the reasons you mention. In open water they are vulnerable to birds from above and fish from below. Even in small ponds, when frogs are startled and leap into the water, they usually turn right around and swim back toward shore. I think that your scenario sounds right: heavy rain runoff washed them out into the lake while they were in a semi-stupor due to cool temps, and they swam back to the nearest land when they woke up sufficiently to swim. Any that don’t make their way back to the sheltered area with vegetation are probably goners.
I’d be surprised to learn that frogs winter at the bottom of Lake MI, especially in that area.
The bottom of the lake is nearly all sand, and the waves can be astonishingly large, especially in that area during a storm with strong winds from the North. Six footers wouldn’t be uncommon. I’ve sailed in 10 footers at the other end, near Petosky and Mackinaw.
Have you ever seen what happens in shallow water with 6 foot waves? Between waves, the water flows FAST (away from the shore), and it shifts the bottom rapidly: it’s easy for the bottom in any one spot to go up or down more than a foot in a matter of minutes.
In addition, most shores of the Great Lakes slope very gently, so the water is quite shallow (less than 10 or 15 feet) for quite a ways. Unfortunately I don’t have any nautical charts to say how far, in that area, but from images I can find it looks typical. How far out would a frog go, to find relatively safe/still waters to hibernate in? There’s little for them to eat once they wake up, either.
You’re generalizing. I can point out specific spots that have quite a different underwater terrain than you describe, within hiking distance of my house.
Nevertheless, I think most frogs winter up a creek. I’ve never seen them on my sand beach even though there are 3 small creeks within a 2-mile radius. I don’t think they go far from safety if don’t have to. Walk by the creek bank and they will get flushed out by your presence (in the summer). That doesn’t happen by the Michigan shore because they aren’t there.
Like I said above, I’m pretty familiar with frog behavior, but not that familiar with the Great Lakes, despite having lived in southern Ohio for the past twelve years.
The descriptions from you and the OP make the shoreline and lake bottom in that area sound totally undesirable from a frog’s point of view. They like heavily vegetated edges of shallow water for day to day activities, and water just deep enough not to freeze solid for hibernating. For hibernating, they need something to bury themselves, just deep enough to cover their bodies, and loose enough to allow oxygen flow.
Musicat’s experience fits with my knowledge of frog behavior. An unsheltered beach on a big lake is not their preferred habitat. The only requirements of theirs that it meets is wetness.
Good catch on my jumpy sentence construction.
Now I have the Walrus and the Carpenter going thru my mind…
Stopped by the nature center yesterday, and they pretty much agreed with our theorizing.
First off, it WAS a bullfrog.
(This old dog FINALLY found a use for his whizzbang new smartphone!)
I had been focusing on the color, but instead I guess the distinguishing characteristic was the ridge around the eyes as opposed to down the back.
The staff said the weekend rains had been the heaviest since April (not sure how significant that is, given this summer of drought.)
But they most likely washes down that creek to the lake, where the prevailing current/waves carried them to the SE where I saw them.
Staff agreed that frogs do not generally live IN the lake right there, and that the majority of them were soon to become gullpoop.
Observed same thing today 9/29/24 multiple huge bullfrogs along Lake Michigan shoreline just east of the Pavilion at the State Park. We did have some rains. Also interesting was the creek had been dammed up and broke through last night flowing back into Lake Michigan.
