False spring: Climate change may erode frogs’ ability to withstand salt pollution

Peer-Reviewed Publication



BINGHAMTON, N.Y. — Climate change may erode frogs’ ability to withstand road salt pollution, according to researchers at Binghamton University, State University of New York.

Driven by climate change, spring in the northeastern United States is now earlier and more variable in temperature than it used to be, a shift that has rippled through ecosystems. Among the most severely affected are spring-breeding amphibians such as wood frogs, who may be lured out of the mud to mate too early.

When winter comes rushing back in, adult wood frogs will likely survive the chill — but their newly laid eggs may be at risk. But the impact doesn’t end there, according to new research by Binghamton University’s Department of Biological Sciences.

Later broods of hatchlings whose parents endure freezing temperatures associated with an additional winter storm are larger but less resilient to the effects of road salt, a common wetland pollutant, according to doctoral candidate Nicholas BussAssistant Research Professor Lindsey Swierk and Associate Professor Jessica Hua in “Amphibian breeding phenology influences offspring size and response to a common wetland contaminant,” published recently in Frontiers in Zoology.

The research focuses on several populations of wood frogs located about a 4½ hour drive southwest from Binghamton, which typically enter breeding season anytime between mid-March and mid-April. It also addresses a common but sometimes overlooked environmental pollutant: salt.

Every winter, 10 million metric tons of road salt are applied to North American roadways, washing off in the melting snow and spring rain. This runoff can increase the salinity of nearby wetlands and prove toxic to freshwater species such as amphibians, Buss explained.

Amphibians are an essential component of wetland ecosystems. As tadpoles, amphibians feed on algae, increasing water clarity and quality of wetlands. Tadpoles additionally serve as prey to many species of aquatic invertebrates, making them important contributors to the cycling of nutrients within wetland ecosystems.

Early spring and offspring

A combination of factors spur amphibians to mate, often hinging on both temperature and the timing of spring rain, Hua explained. For wood frogs in particular, researchers predict their breeding time by the absence of ice on the pond, a string of three to four days above freezing, and rain during those days.

While amphibians are cold-blooded, warmer weather isn’t necessarily better. They evolved their breeding schedules over thousands of years in response to environmental cues, Swierk said. In comparison, climate changes over the last few decades have been rapid, testing the limits of these species’ ability to cope.

“Our results suggest that the effects of climate change on wood frog breeding are complex, depending on the severity of freezing events from year to year, and are interactive with other human-introduced stressors like contaminants,” she said.

Adult frogs that emerge during a false spring are often capable of surviving, thanks to unique adaptations that allow them to cope with freezing temperatures. The eggs themselves may be a different story.

“Though each wood frog female can lay over 500 eggs, many of these eggs may be vulnerable if the pond freezes over,” Hua said.

The embryos, too, are hit hard by sudden cold. In a previous study, the researchers exposed frog embryos to cold conditions and found that they took longer to develop into tadpoles, weighed less after hatching and were less tolerant of road salt than embryos raised in warmer environments, Buss said.

For the study published in Frontiers in Zoology, the researchers removed the eggs from the environment in which they were laid and raised them in the lab. They found that eggs laid later in the mating season by parents who were exposed to an additional winter storm were less likely to withstand salt pollution.

The researchers suspect that earlier-breeding frogs were exposed to less temperature-induced stress than those that bred later, which may have translated into less physiological stress and a better ability for those early breeders to acclimate to increased salt in the environment. While stress hormones can allow animals to survive when faced with temporary adverse conditions, prolonged or severe exposure to stressors can cause those same hormones to have ill effects, Swierk said.

“Chronically elevated stress hormones can have cascading impacts on other hormones, such as those related to homeostasis, growth or reproduction,” she explained.

In the short-term and on the local scale, it’s not possible for us to change these larger climate patterns. However, local management can be made aware of the exacerbating effects of pond contaminants on amphibians that breed too early, Swierk said.

“From an evolutionary perspective, it is fascinating to understand how animals can adapt, or fail to adapt, to rapid changes in their environment,” she said.


Frontiers in Zoology




Amphibian breeding phenology influences offspring size and response to a common wetland contaminant

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September 15, 2021 10:05 am

Lots of maybes in that study but that didn’t stop them from throwing in the requisite “Climate Change” to get it peer reviewed and published.

Reply to  markl
September 15, 2021 10:11 am

But spring in the northeastern United States is now earlier and more variable in temperature than it used to be, isn’t it? so if that’s not climate change….?

Reply to  griff
September 15, 2021 11:54 am

It’s not.
One of the dusty little corners of AGW research is that the in the US, the “Lower 48”, as it is, there has been no AGW. Indeed some of the regions have shown cooling over the last 50 years. Absolutely, there has been no general warming trend.
The warmists often protest Global, Global, Global and the US is just 7% of the planet land area. (or some such) Therefor the US does not matter.
OK, whatever.
But when the biology people claim AGW is affecting this or that species in the Lower 48, one can fairly ask “What warming, where, and how much?”.

When this fact is pointed out and the question asked at a biology conference, one instantly becomes “The Skunk at the Garden Party”. Ask me how I know.

Reply to  TonyL
September 15, 2021 12:24 pm

For anybody interested in TonyL’s quite correct comment, check https://www.ncdc.noaa.gov/crn/visualizations.html for the average lower48 temperature as measured by the Climate Reference System. It consists of 112 or so automatic weather stations with triply redundant sensors for temperature and other parameters. Each of the stations is placed far part from any human structure or influence, are spread uniformly over the surface of the country and report data electronically. And the data are not “adjusted.” The CRS clearly shows that the average temperature of the lower 48 has not changed since the system was placed in service in January 2005.

Richard Hoard
Reply to  DHR
September 15, 2021 1:26 pm


Jim Gorman
Reply to  TonyL
September 16, 2021 6:04 am

How true. I have posted about this before. A change in Global Average Temperture (GAT) is made up of temps from the whole globe. One can not simply assume that local temps follow the GAT to the nth degree.

Few of these studies follow the scientific method of obtaining proper measurements of any number of variables. In this case, what is the temperature/egg relationship in a controlled environment? As you say, what is the actual local temperature profile? How has the population actually fluctuated over the time frame of years? How much has the salt concentration actually varied?

You know the old saying about “assume” when applied to GAT!

Reply to  griff
September 15, 2021 12:11 pm

Do you for once, have any evidence that spring is earlier and more variable?
Beyond that, just because something changes, is not evidence that CO2 caused it to change.

Joao Martins
Reply to  griff
September 15, 2021 12:27 pm

griff, are you saying that climate change made the Moon rotate around the Earth faster????

Last time I checked it, “Spring” starts at the March equinox… It is not like Easter that falls in a different day each year! Begin of Spring is a very FIXED date! And it is the same all over the world, it is not different in the NE USA!

Reply to  Joao Martins
September 15, 2021 4:42 pm

I completely disagree! I was looking into this seriously, in more detail, to make the observation tighter and more focused. Because Spring is about 90 days, I broke the interval up into thirds and I have concluded that March is where the problem resides. It used to start on the first, but I am 95% certain March is starting before the first.

Once I finish my analysis, I plan on submitting my findings to an academic journal, as I think this is an original finding. If you Google “______ is starting earlier” for any month of the year, Google returns “no results“. However, if you put Spring in the blank, Google returns thousands of results.

And so once I have proven that March is starting earlier, my findings then can be extrapolated to Spring, because if a month can start earlier, then it logically follows that Spring can as well, because March is a sub-unit of Spring. And, therefore, the logical converse is true as well.

Joao Martins
Reply to  Anon
September 16, 2021 3:12 am

And I completely agree with you! The time has come to replace plain facts with Google facts!

Alan the Brit
Reply to  Joao Martins
September 15, 2021 10:16 pm

Surely it varies slightly due to the Precession of the Equinoxes as part of the Milankovich Cycles?

Joao Martins
Reply to  Alan the Brit
September 16, 2021 3:06 am

Yes, you are right! How much milliseconds per year?…

Reply to  Joao Martins
September 15, 2021 10:17 pm

The moon is moving away from the earth at 38mm per annum (1.5″)

Using the twisted logic of the CAGWers, this is the reason wolves howl at the moon

Alan M
Reply to  Redge
September 16, 2021 1:12 am

No no Redge, it’s the other way round. The moon is moving away because wolves are howling at it.

Reply to  Alan M
September 16, 2021 5:00 am

Moon moves away because the wolves howl

Wolves howl because the moon moves away

That’s the sort of circular reasoning climate scientists would approve of 😉

Reply to  griff
September 15, 2021 3:24 pm

I live in the US northeast. It is not getting warmer in the spring. I have lived here for 31 years. Spring temps were higher in the 90s. In 2015 there was a frost on 20 May, which tied the latest date for a frost. In 2020 we saw 2” of snow in May. I used to set out tomatoes, peppers, & eggplant in mid-May. Stopped doing that in the 2000s, as the last frost dates moved out of April into May. I used to have ripe tomatoes by mid July in the 90s, now (using the same methodology and same varieties) can expect ripe tomatoes by late July or Early August at the earliest.

Tom in Florida
Reply to  griff
September 15, 2021 4:02 pm

If we let the Earth get warm enough there will be no need for road salt (as in Florida). Problem solved.

Reply to  griff
September 15, 2021 10:05 pm

If, and I repeat if, spring is a little earlier in the NE US, then it could be down to climate change.

In itself, this tells us nothing about the cause of that change.

It is merely conjecture.

Reply to  griff
September 15, 2021 10:26 pm

It’s time to start embargoing griff’s comments until 10 other people have commented. griff uses an app to spot new postings here and then jump in to clutter up the top comments, the ones most people look at. griffjust clutter up the comments section and takes away bandwidth from people who have more well-thought-out things to say.

Perhaps the moderators could send griff an email telling them to voluntarily restrict their comments to outside the first ten. If they don’t comply, deleting one or two should get the point across.

Reply to  markl
September 15, 2021 11:39 am

This trash wouldn’t be about AGW but about water pollution if the the agenda and therefore money and fame would be about water pollution.

But no matter how stupid this is.It’s nothing compared to the recent “dragonflies change wing patterns faster than ever before because of AGW”.Though they do not have nearly enough samples of any 3 decade period of the past 300 mio years (to compare it with the 3decade AGW period) nore the ability to determine the age of superold and even younger fossils,and though dragonflies lived during much warmer periods with much muchhigher co2 levels these experts somehow concluded that dragonflies of the AGW period suffer the most.

There is a simple reason for this.
Just like communism AGW is so universal and inclusive that any science can be part of it as long as the official Agenda is being parrotted.
(I’m even sure that Bidens psychopathy and dementia and the size and shape of his poo can be explained with AGW)

September 15, 2021 10:08 am

If it’s warm enough to “entice” the frogs to come out of the mud earlier, then by definition, it’s also warm enough to make the last snowfall come earlier as well.
As a result the time between the last snow and the first frog will stay more or less constant.

How typical of climate alarmists to only look at one factor in a complex subject.

September 15, 2021 10:22 am

So children (maybe) won’t know what snow is and (maybe) governments will spread the road salt anyway because it’s in the budget and the federal funds.

Reply to  ResourceGuy
September 15, 2021 12:02 pm

but but…how can snow be a thing from the past when recently experts found out that a massive increase in snowfalls is the reason sea level ain’t rising despite all the record melt in greenland,antarctica.

It’s for sure a pain to synchronize all AGW lies when everyone and his dog wants his 15 minutes of scientific pain and 15 years of funding.

All this craziness reminds me of the money the british wasted in india to reduce the number of snakes.
The more bounty they paid for a dead snake the more snakes were killed.
The more snakes were killed the more deadly snake attacks happened.
After the brits stopped paying money for dead snakes the snake population went down to normal levels.
The explanation is simple.
As soon the brits started paying money for snake scalps,certain hindhus started breeding snakes big style.
Nowadays AGW is the snake.

Krishna Gans
September 15, 2021 10:28 am

Do I understand that right, Climate Change is used to explain more salt on the streets, ähem, because of less snow in a warming world ? Or is there more snow and Climate Change not so hot as predicted ? Can’t follow….. 😀

Barry James
September 15, 2021 10:29 am

We should get Tony Heller to satirize this one.
I’d love to see him shred it.

September 15, 2021 10:29 am

What a load of BS.

Reply to  Chaswarnertoo
September 15, 2021 10:50 am

At least they didn’t say that they all are going to croak in ten years.

Reply to  Scissor
September 15, 2021 12:13 pm

But he will hop right on it.

Ron Long
September 15, 2021 10:31 am

First of all wood frogs live primarily in wooded areas, but can venture into ponds sometimes. Secondarily, judging from the descriptions of their daily conduct and preferred habitats the average wood frog from never gets close to a roadway and therefore is not involved with road salt. Thirdly, who the hell cares? If it’s them or us, I vote for us.

Reply to  Ron Long
September 15, 2021 12:33 pm

It is fun to chase frogs in the woods! That’s what little boys do.

Pamela Matlack-Klein
Reply to  Ron Long
September 16, 2021 12:38 pm

Wood frogs are forest dwellers and vernal pool obligates. When the vernal pools begin to form in the early spring the frogs thaw and come out of the leaf mold then head for the nearest wicked big puddle to mate, lay egg masses, and then vanish once again into the forest. I have occasionally found wood frog egg masses alongside traveled roads but usually you have to trek into the forest a bit in search of a vernal pool.

September 15, 2021 10:40 am

For the study published in Frontiers in Zoology, the researchers removed the eggs from the environment in which they were laid and raised them in the lab. They found that eggs laid later in the mating season by parents who were exposed to an additional winter storm were less likely to withstand salt pollution.”

So they have solid evidence that eggs and tadpoles of wood frogs, in a lab setting, have problems when researchers jack the water temperatures around and throw salt in the water.

Fine. I’m sure their results were actually observed and carefully recorded.

Now they just need to go out and monitor a few dozen ponds over the next decade or so to record what is actually happening with wood frogs. I’ll wait for those results.

BTW, if the warmth of Spring is coming earlier and earlier and snow is a thing of the past, am I supposed to be alarmed here or something? It seems to me that ‘Climate Change’ would be a win for wood frogs.

J Mac
September 15, 2021 10:54 am

It’s not easy, being green….

September 15, 2021 11:14 am

“Though each wood frog female can lay over 500 eggs, many of these eggs may be vulnerable if the pond freezes over,”

In a warming world things get colder…

Reply to  fretslider
September 15, 2021 12:14 pm

A dash of salt would make it harder for the pond to freeze over.

September 15, 2021 11:23 am


The old SUNY-B, State University of New York – Binghamton.
Almost the entire student population was from the greater New York City area, Long Island and Westchester County. Urban creatures all, not the most “outdoors” types at all.

Winter of 1976-1977:
The student newspaper blasts the headline in the largest type they have:

“Worst Blizzard in a Century”
“Binghamton Blasted by Over One Inch Of Snow”

Not a joke. At All. The whole student body Freaked Out, the campus was shut down for two days. At first I was totally confused, I had just come from 4 years in Ski Country and was an avid downhill skier. All this panic and commotion was all about one inch of snow. That is all of 2.5 centimeters. You do not even need gloves to clean off your car, just bare hands works fine.
I took several copies of the newspaper and saved them for years as souvenirs of insanity.

Item 2:
On the center/west side of the campus there is a huge lawn, oval shaped, and surrounded by academic buildings. Between classes, the place is very busy with thousands of students moving from class to class. While class is in session, the place is deserted.
I was just coming along and spotted a fully grown white-tailed deer right in the middle of the lawn. Just hanging out, apparently. Within a few moments, “the bell rang”, anf the lawn was instantly full of thousands of students, all going in every possible direction.

The deer was ready to panic and bolt until, until…. until…..
The deer realized that nobody has seen it, nobody had noticed it at all. The deer must have discerned that it was functionally invisible. The deer simply watched as people moved all around it to and fro and never once noticed it. The deer picked out two girls gossiping nearby, perhaps 50 meters from me. Something in the purse of one of the girls attracted the animal, and it tried to stick it’s nose in the purse. The girl kept yanking the purse away as the deer kept tugging on it. The girl never stopped gossiping, never turned and looked, but did notice me.
After a few minutes, the lawn was almost empty again as the students went to their next class. The two girls came over to me and accused me of being part of a purse-snatching ring. They informed me that they were from the city (NYC of course), and were Street Smart and City Wise. My feeble attempts at thievery would not work with them. I told them they could just look over their shoulders and see the deer close up. They declined and stomped off, all in a huff.

The deer looked around, nobody left in sight except me, so it trotted off in the direction of the Student Union building.
A few students at the Student Union did notice it, got some pictures, and the deer was featured in a front page story in the student newspaper, just as breathless and excited as the Blizzard story.

Item 3:
At the other end of campus is a frog pond, a so called “wild area”. The environment is 100% landscaped and 100% managed, along with the lawns nearby getting mowed. There is nothing “wild” about it. In spite of that little detail, the frog pond was the subject of intense research by the various biological science groups on campus.


Pamela Matlack-Klein
Reply to  TonyL
September 17, 2021 5:14 am

Hilarious! As a veteran of hundreds of hours spend slogging through vernal pools in February-March, I have seen similar reactions to real wildlife from city kids. The smart ones get over it fast and learn to truly appreciate all that there is to learn.

John R
September 15, 2021 11:24 am

Road Salt will also affect the life cycle of slugs….. whether the climate is warming or cooling!

Reply to  John R
September 15, 2021 12:29 pm

If you can work in ‘Climate Change’, apply for a grant, John.

Lessee…. warming causes cooling, which means more snow, which means more road salt, which means “THE SLUGS ARE ALL GONNA DIE DUE TO CLIMATE CHANGE!

There ya go. Just get a salt shaker, find a couple of slugs, sprinkle salt on them, watch them die, write it up, and cash the grant check.

Wait… cash the grant check first.

September 15, 2021 11:37 am

The earliest known “true frog” is Vieraella herbsti, from the Early Jurassic. It is known only from the dorsal and ventral impressions of a single animal and was estimated to be 33 mm (1.3 in) from snout to vent. Notobatrachus degiustoi from the middle Jurassic is slightly younger, about 155–170 million years old.”

Frog – Evolution (liquisearch.com)

They’ve been around for a while, I think they’ll be here for a good few years yet.

September 15, 2021 11:49 am

If you want to make a claim about climate change, it seems the best words to use are: may, might, could, possibly, believed. This isn’t science!

Captain Climate
September 15, 2021 12:04 pm

Spring is earlier, because of warming, so the frogs are colder. Got it. And variability of day-to-day temperatures has never been an issue for frogs before, because Binghamton is a beautiful place to be in March-April and it’s totally unheard of that there would be snow on the ground and cold days then.

September 15, 2021 12:14 pm

Wood frogs live as far south as Alabama (average annual temperature of 63F) as as far north as Alaska (average annual temperature of 27F.) With such a broad range of temperatures in its preferred environments, and with road salt widely used in all, it seems unlikely that “climate change” could possibly have any effect on the wood frog.

Pamela Matlack-Klein
Reply to  DHR
September 17, 2021 5:18 am

Wood frogs that live in cold winter areas are capable of freezing solid and then thawing out and coming back to life. How they are able to do this and not be killed or damaged is much more interesting than any possible harm they might suffer from a little road salt. Their chorus song sounds like a bunch of ducks quacking too, really a nice song.

September 15, 2021 12:40 pm

I’ve seen middle school science fair projects better than this.

Pillage Idiot
Reply to  philincalifornia
September 15, 2021 12:58 pm

We all have. And the kids that won the blue ribbons went on to become actual scientists in rigorous disciplines.

The kids who had worthless projects that didn’t show any understanding of the scientific method went on to other fields – or perhaps became “climate scientists”?

Reply to  Pillage Idiot
September 15, 2021 1:20 pm

The boiling oceans theory of James Hansen, the most wrong calculation ever in the history of science.

There is water at the bottom of the oceans – Travesty Trenberth

Oh sorry, that was the Talking Heads.

We need a new null hypothesis – Travesty Trenberth

I’ll fix that pause – Trofim Karl

I won a Nobel Prize, honestly I did – Michael Mann

There’s plenty of support for your hypothesis

Mickey Reno
September 15, 2021 1:26 pm

Milking the CAGW climate alarm funding machine for all it’s worth… nice job, sucklings!

Gordon A. Dressler
September 15, 2021 3:00 pm

“Climate change” may enable me to finally win a Powerball Lottery, but I’m not counting on it.

Sky King
September 15, 2021 3:54 pm

Road salt and frogs – another thing to keep me up at night!

H. D. Hoese
September 15, 2021 5:47 pm

I have some interest from doing a graduate herpetology course experiment on salt water (not all NaCl) effects on tadpoles to working in low salinities where they are usually excluded. They do have a problem due to their permeable skin, but there are some papers on them out west where natural salt accumulates, maybe covered in review mentioned (“In doing so [review of 144 species], we make the case that salt tolerance in amphibians may not be as rare as generally assumed.”).

Paper is open access, seems all over the wallpaper, not completely fair to judge on dates, but the three I found earlier than this millennium were 1972 on immune response of pokilotherms, 1969 on squirrels and frost, and 1986 on trees. A recent one on cadmium, a complicated toxicity element, showed sensitivity due to temperature.

This statement in the paper requires a careful study of methods.
“Interestingly, the ability for wood frogs to acclimate to NaCl differed between earlier versus later-breeding cohorts in 2018. Specifically, the later-breeding cohort of 2018 whose parents experienced a freezing event prior to breeding gave rise to offspring that were less capable of acclimating to NaCl exposure compared to the earlier-breeding cohort of the same year whose parents did not experience such events.”

Their Fig. 6 shows effect in 2018 but not 2019. Differential breeding is very common among species, don’t know about wood frogs. One would suspect so since climate does vary from locality and year, even lesser dates. I would suspect that a recent freeze would cause all sorts of changes in later tolerances. Long known that amphibians suffer from human pollution, but there was a juvenile tree frog on my front door handle yesterday.

Tom Abbott
September 15, 2021 6:07 pm

From the article: “Driven by climate change, spring in the northeastern United States is now earlier and more variable in temperature than it used to be, a shift that has rippled through ecosystems.”

Where’s the evidence for this bold statement?

September 15, 2021 7:58 pm

I thought there was going to be warmer winters… therefore less salt needed…

And snow was going to be a thing of the past..

September 15, 2021 8:52 pm

Frogs evolved 375 million years ago and have been through many periods of climate change including the earths hot house and ice house conditions, plate tectonic actions and tremendous sea level rising and fallings.

I wouldn’t worry too much about frogs adapting to climate change, after all they do have legs and can hop away.

September 15, 2021 10:00 pm

It seems the only thing CO2 can’t do is knock some common sense into these people

September 16, 2021 10:25 am

Seems never seem to go right for the French

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