New tool in tracking climate change: bat poop

From the UNIVERSITY OF SOUTH FLORIDA (USF HEALTH) and the “bat signal” department comes this story about crap science paleo-guano.

Bat Poop: A Reliable Source of Climate Change

People have long known that bat guano – the polite term for what the flying mammals leave on the floors of caves where they live worldwide – is a valuable source of fuel and fertilizer, but now newly published research from University of South Florida geoscientists show that the refuse is also a reliable record of climate change.

In a new paper published this week in the research journal Scientific Reports, USF geochemistry Professor Bogdan Onac and PhD student Daniel Cleary report that isotopes found in bat guano over the last 1,200 years can provide scientists with information on how the climate was and is changing.

The scientists examined bat guano from a cave in northwestern Romania to produce new insight into how the climate in east-central Europe has changed since the Medieval Warm Period, about 850 AD.

Dr. Bogdan Onac finds bat guano to be a record of paleo-data. CREDIT Dr. Bogdan Onac, University of South Florida

Nitrogen cycling within temperate forests is very sensitive to changes in the amount of winter precipitation received each year. When nitrogen isotopes change in response to variation in winter precipitation over the past 2,000 years, this signature is transferred from the soil to plant leaves to insect to bat and ultimately guano.

“Luckily for scientists, the statement ‘you are what you eat’ also applies to bats,” Onac said.

Scientists frequently examine chemical records in natural substances to document how the climate has changed in the past, and to lend insight into how rapidly it is changing now. Scientists drill mud cores into the sediments under the oceans, ice cores in the Arctic and Antarctica, examine tree rings, or use the chemistry found in caves (stalagmites) as climatic proxies.

Bat guano is rich with nitrogen, and scientists know that nitrogen moves through the food change and through animals, where it is returned to the environment.  When bats return to the same location within a cave, guano piles beneath their roost can reach sizable dimensions. The researchers found in M?gurici Cave in Romania is a large three-meter pile of bat guano that has been accumulating for more than a thousand years.

Isotopic analysis of the guano pile in the M?gurici Cave resulted in a near annual record of winter precipitation for the region.  The location of this cave in the foreland of the East Carpathian Mountains means winter precipitation is modulated by the North Atlantic Oscillation (NAO), with wetter conditions influencing the availability of nitrogen within the surrounding forest system. Using historical records of precipitation, a relationship between winter precipitation and NAO phases was established.  Through this work, past phases of the NAO could then be reconstructed back to 1600 AD, Cleary said.

The work represents the first study to provide a paleo-record of this large scale atmospheric circulation pattern for East-Central Europe using cave bat guano. The USF researchers collaborated with Babes-Bolyai University in Cluj, Romania, and the University of Bremen in Germany.



The study was funded with a seed grant from USF that led to a five-year grant from the Romanian Science Foundation, which supported the analytical work of D. Cleary.

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October 26, 2017 4:40 pm

From the article: “Scientists frequently examine chemical records in natural substances to document how the climate has changed in the past, and to lend insight into how rapidly it is changing now.”

They are assuming the climate is behaving differently than in the past, and is currently “changing rapidly” although there is no evidence to back up this claim.

Assuming too much. All the time.

Reply to  TA
October 26, 2017 5:20 pm

I read that more charitably and assumed that one insight as to “how rapidly it is changing now”, could very well be “not very much”.

Reply to  TA
October 27, 2017 12:33 am

They are not ‘assuming’ anything.

they are examining the evidence and reaching conclusions.

The climate has been different in the past and has changed in the past, for different reasons and at different rates.

(and now it is changing rapidly, due to human CO2)

Reply to  Griff
October 27, 2017 2:14 am

Again you embarrass yourself Griff.

The vast majority of current ‘climate scientists’ are fervently trying to find evidence to back their pre-conceived opinions.

That’s why there is an assumption that the models are right and thermometers wrong, and an endless search to find reasons to adjust the temperature record in a direction that suits the theory, rather than looking for all errors with an even hand.

As for your assertion that climate is changing more rapidly, garbage, empirical evidence shows it is within both possible natural limits and possible natural rates of change.

Reply to  Griff
October 27, 2017 4:48 am

Griff, feel free to share your evidence that current climatic changes are caused by anthropogenic CO2 and not whatever natural forcing(s) that caused the very same changes that have occurred many times in the Earth’s past.

Ursus Augustus
Reply to  Griff
October 27, 2017 8:33 am

Gee Griiff, why does the term ‘bat shit crazy’ come to mind?

To paraphrase Wilfred Owen,

Dulce et decorum est
to go bat shit crazy
for a cause

Reply to  Griff
October 27, 2017 4:33 pm

(and now it is changing rapidly, due to human CO2)
Now it’s changeing in more or less the same way as 19 other occasions during the Holocene.

Carbon BIgfoot
Reply to  TA
October 27, 2017 1:37 pm

They know their shit!!!

October 26, 2017 4:48 pm

ok….this is what bat guano looks like….it’s working alive with worms, bugs, etc……then layers to form aerobic, anaerobic, and anoxic zones where bacteria reduce it through nitrification, denitrification, etc and on and on
…I seriously doubt they could find layers that have any meaning at all

But what the’s the U of South Florida what would you expect
comment image

Reply to  Latitude
October 26, 2017 6:36 pm

Bats go a long way down into caves, far beyond where any living worms & bugs could go.

Robert of Texas
Reply to  Enkl
October 26, 2017 8:34 pm

Wrong. If there are nutrients then there is the possibility of insects and other complex life forms. I was an active caver for many years and wherever you found water and bat guano, you could find insects. Some of them were so specialized they had become albino and lost most (possibly all) ability to see, but have elongated antenna for sensing their environment.

There are creatures that live just inside of caves, those adapted to low light, and then those that live in total darkness.

Bats are often infested with tiny lifeforms they bring with them into the caves.

What you do NOT see deep into caves unless close to the surface and with some form of connections are reptiles (like snakes), most mammals (excepting bats that have an available surface connection, they enter further into caves), and birds. You do find fish, crustaceans, and insects. I can attest to this personally.

Person pointing out that bat guano is mixed in the upper layers is absolutely correct. Wet guano is nasty stuff mad nastier by the community of live critters in the upper few inches. Sick and young bats often fall into it mixing it up further. Bat communities grow and shrink over time so that the layering is uneven and patchy. I cannot imagine trying to sort out all of the variables that could contaminate a sample if you are assuming it is not disturbed.

Dr K.A. Rodgers
Reply to  Latitude
October 26, 2017 7:38 pm

Before i spotted Latitude’s comment I had be going to blog that unless the different guano layers could be demonstrated to have remained closed systems since deposition their isotopic contents were not worth a tinker’s cuss.

Reply to  Dr K.A. Rodgers
October 27, 2017 7:00 am

That’s why they created error bars

The Great Walrus
Reply to  Latitude
October 26, 2017 7:57 pm

Looks like the leftovers in my fridge (i.e., tomorrow’s microwaved dinner).

Reply to  Latitude
October 26, 2017 9:31 pm

What about associated fluvial deposits in the same cave?
Only way they could claim a “near annual record”.

Reply to  Latitude
October 27, 2017 4:46 am

In the end the data will trump your ideas.

There will be a modern record of nitrogen in the poop and precipitation.
there will be record of nitrogen in the poop going back in time.

Using the data a reconstruction will be proffered.

That is all.

1. There will be assumptions, there always are.
2. There will be a proposed pattern of precipitation, of NAO.

This will represent only one approach to reconstructing natural variability in a region.

There will be others. In the end you will have a proposed picture of what the past looked like
when we had no instruments.

FOlks wont care about your blog comment. They will care when you publish something and have it reviewed.
hard fact.

Reply to  Steven Mosher
October 27, 2017 4:39 pm

Amgen recently repeated the experiments published in 53 of the most high-impact recent journal papers in cell and cancer biology. Only about ten of them could be reproduced. Have you not been following the crisis of (non) repeatability in modern science? Do you imagine climate science is unaffected? Imagine it not.

But you’re right. Better proxy data will gradually accumulate like bat poo. And AGW alarmism will gradually get buried under it.

Tom Halla
October 26, 2017 4:49 pm

A thousand years of records that is only readable from 1600 AD? A bit of a disconnect here.

October 26, 2017 5:08 pm

Another “use the magic word and you win a prize” (remember Groucho Marx?) study. Not only will we publish your research/theory/thesis/random thoughts but we’ll make sure it gets through any significant peer review unencumbered by facts. Anyone that thinks ‘science’ is behind all these ‘more proof of AGW’ papers needs to do some serious introspection.

Reply to  markl
October 27, 2017 1:24 pm

I’ve seen this a number of times. These guys may have just wanted to analyze the guano to see if any conclusions can be made. If you then toss “indicative of climate change” into the proposal, you get funding. Otherwise, not.

October 26, 2017 5:21 pm

This research could well lead to a Nitrogen tax.
We may have the Nitrogen tax before we get the Gravity tax.

F. Leghorn
October 26, 2017 5:20 pm

that nitrogen moves through the food change ”

The food change. Say what?

Reply to  F. Leghorn
October 26, 2017 5:27 pm


October 26, 2017 5:22 pm

Bogdon looks to be between a rock and a hard place.

October 26, 2017 5:26 pm

Talk about basing your entire premise on a pile of …..
And then dig it deeper and reconstruct north Atlantic weather patterns.
Who in their right minds will ever attempt to replicate their work, let alone data collection methods?

October 26, 2017 6:11 pm

They used to use chicken’s entrails for the future, now it is Bat Poo for the past.

Gary Pearse
October 26, 2017 6:36 pm

He has a hard hat and glasses. I should think a pith helmet would be a more comfortable hat for deflecting what’s falling on his head and maybe a face mask for fungus toxins or whatever these creatures’ droppings cause.

October 26, 2017 7:02 pm

Did they core the bat guano pile, or how did they establish the layer they were studying was the sample that was supposed to be reflecting the age/date of the droppings? While the bat guano may accumulate in a pile, how do they know that something didn’t disturb the ‘pile’ like a flood of water, or some other animal stirring up the mess into a homogenized pile of mixed up bat shite. A sediment core, tree ring or stalagmites are going to have much more reliable surface to study, unlike a steaming pile of bat guano. I don’t know about this one either…On first glance, it sounds like students wanting to publish something and fitting the NAO to the pile of bat guano, not the other way around. Maybe I am just too skeptical.

J Mac
October 26, 2017 7:08 pm

It’s a crappy job, but somebody has to do it!

A 3 meter pile = 3000 mm.
Accumulating for 1000 years = 3mm/yr.
‘Phases of NOA established back to 1600AD’ means either the guano ‘record’ below (416yr x 3mm/yr =) 1.248 M was unusable or there was some other conflict that limited their correlation confidence to the 1600 – 2016AD interval.

I’d like to read this report…. before I reject it as having only fertilizer value!

October 26, 2017 8:29 pm

These guys were studying signs of precipitation and correlated it to the North Atlantic Oscillation (NAO). It doesn’t appear to say anything about global warming (at least from this article). Seems they threw the Climate Change words in there just to make sure they could get published.

October 26, 2017 9:43 pm

Colonel Bat Guano:

Joel O’Bryan
October 26, 2017 9:43 pm

Grant submission:
Bats do things that might be important like eat insects and spread diseases. Bat poop and it does stuff like carry viruses and disease. Climate change could affect that in ways we don’t understand. Send money.
reference: see our peer-reviewed published paper.

Key words: change change, money.

Nigel S
Reply to  Joel O’Bryan
October 27, 2017 12:40 am

Change and decay in all around I see:
O thou who changest not, abide with me!

M E Emberson
October 26, 2017 10:02 pm

There was a huge trade in guano in the 19th century. People made fortunes loading it on to ships.
It is traded still. It was the fertiliser of the century.
Guano is the name the Chileans give it.
This is them trading it still.
Mostly it is sea bird droppings out on the shores of small islands with bird colonies
Bat droppings in caves would not be in identifiable layers but seabirds might build up layers year by year,possibly but not certainly.

Reply to  M E Emberson
October 26, 2017 11:54 pm

Yes, the Island of Nauru and Ocean Island in the Pacific were ‘owned’ by the British Phosphate Company.
They were literally excavated and removed to Australia and NZ and to Europe to fertilize farm land.
Been there in the 1970’s. Nauru has now mostly reverted to being a crater.

Nigel S
Reply to  M E Emberson
October 27, 2017 12:54 am

When I (briefly) studied law this case caught my eye.

Compagnie Financiere du Pacifique v Peruvian Guano Co (1882) 11 QBD 55 is a foundational case in the law of evidence holding that a plaintiff party must disclose to a defending party “all documents in his possession or under his control relating to any matters in question in the action.”

I enjoyed the names (from an era when companies were not ashamed to state their business) as much as the case. The irony of this statement from UEA on openness and transparency is pretty enjoyable too.

The UEA said: “We have nothing to fear from scrutiny; we are committed to openness and transparency in our research… and we fully intend to make all data publicly available as soon as possible.”

October 26, 2017 10:26 pm

Good enough for calibrating the standards applied to proxies of average global outside air composition and temperature fractions eons ago. Confidence interval remains within various mammalian faces.

James Bull
October 27, 2017 12:20 am

My first thought was they will have to be quick because once the windmills are installed everywhere there won’t be many bats left and so the “historical record” will end and so they won’t have any new layers to study.

James Bull

Tom Judd
Reply to  James Bull
October 27, 2017 6:45 am

The difference in the depth of the layers will be the new proxy for climate change. They will calculate the number of windmills constructed yearly by the reduction in depth of guano from the reduction in the bat populations. They will then calculate that each windmill reduces global temperature by 0.000000000000000000000000000000000000000000000000000000000000000000001 degree. Multiplying the number of windmills by that figure will yield the change in global average temperatures. And, they will claim that bat guano provides a more useful proxy to measure global temperatures than the record from the satellites.

Crispin in Waterloo
Reply to  Tom Judd
October 29, 2017 11:43 am

Tom J

You are confirming my hunch (we only need hunches in Cli Sci) that the answer to a system with too many bat-killing wind turbines is a heck of a lot more wind turbines to make up for the loss of guano. More will solve everything! Think of the jobs that will be created.

Also keep in mind that the absence of bats means a larger number of turbines will be required to keep the insect population under control. We can add fly swatters to the end of each blade.

October 27, 2017 12:20 am

I call BAT SHIT- or is it BULL SHIT! As the organic matter decomposes, soluble nitrogen compounds will permeate the pile, and I doubt if there would be much useful stratification of nitrogen compounds, and even if there were, each “layer” would represent a wide number of years, possibly all of them. And as a person above commented, given insect and other invertabrates working the pile, it would get mixed beyond all usefulness. THis “science” is simply NOT credible.

D. J. Hawkins
Reply to  navnek
October 27, 2017 8:09 am

Guano is guano because bats and birds are excreting non-soluble or low-soluble nitrogen compounds. It’s why they don’t pee.

Crispin in Waterloo
Reply to  D. J. Hawkins
October 29, 2017 10:54 am

Learn something new every day!

October 27, 2017 12:33 am

Some nut posted this at The Blackboard on October 19th, 2009 at 3:21 pm

I think that I shall never see
A T-stick lousy as a tree.
For trees will thrive in damp or heat,
Adapting to the climes they meet.
And bears go in the woods, they say,
To fertilize them night and day.
Each bruin finds the perfect spot,
In weather cold or weather hot.

Pimply PhD’s in sandals
Search’d for temper-ature handles,
Looking for some sort of proxy,
Whether good or whether poxy:
Maybe how lake silt behaves?
Or bat poop laminae in caves?
At last, they thought they’d found the key
in Dildoclimatology.

Stephen Richards
October 27, 2017 1:08 am

I’ve got loads. I have to vacuum it out of my garage regularly. They shit everywhere they go but layers ??? Each packet is more than 3mm thick.

Nigel S
October 27, 2017 1:15 am

The Native Guano Company works in Kingston, London opened in 1888. Sewage from Kingston and Surbiton was treated at the guano works to produce water clean enough to be put into the Thames and solid matter that was dried, ground and sold as fertiliser. Unfortunately the smell in the town from the sludge drying caused complaints and the Corporation was forced to terminate the guano company’s lease in 1909. The fertiliser was exported as far as Barbados and Singapore. Tomato seeds will still germinate after passing through the human digestive system and an unacceptable amount of weeding was needed in domestic gardens.

‘Native Guano’ is perhaps a bit euphemistic but I think it still qualiifes as an unabashed company name.

D. J. Hawkins
Reply to  Nigel S
October 27, 2017 8:02 am

Milorganite is a similar product, produced by the city of Milwaukee since 1926.

October 27, 2017 2:43 am

Well if this study given them access to the ‘ Bat shit crazy ‘ world of climate ‘science , why not .
Its easy money and no real need to do good academic work and they can just hand around all day just dropping off the odd item of ‘BS ‘ like the rest of the profession.

The Original Mike M
October 27, 2017 7:11 am

John Cook should be encouraged to write a paper on the psychological profile for people who “dig” bat guano and manufacture a consensus for what it smells like.

Reply to  The Original Mike M
October 27, 2017 8:03 am

In Britain bats have colonised many old and historic churches, to the detriment of ancient stonework and woodwork, and a law forbids disturbing them unless you can find alternate accommodation for them and help them there. Plenty of bat droppings and urine in those!

Svend Ferdinandsen
October 27, 2017 2:23 pm

Every change in nature is by default a sign of climate change. The building of windturbines is also a very solid sign of climate change. Climate change can explain every changes you may observe. Just look out the window and you will observe the climate change.
What a marvelous theory that explains everything.

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