Beaverdata Audio

Audiorecording beaverlodges in and around the Peene valley.

Why publishing data?
Why collecting data?
Autor and thanks to...
Using this data, copyright und some toughts.

How to download and analyse these data
Questions and feedback
Autor and lodge sites

The use of the Beaver-Audio-Project (a short review)
Beavers: a pest, a treat or on a threath?

Some beaver sounds (examples)
All files

Why publishing?
Thousends of wild animals get ringed, radio-tagged, photographed, filmed and so on to learn more about them.
These kind of studies may cause harm and disturbance to the animals. When, however, the use and the risk are in balance, such studies are normally permitted.
Unfortunately the data resulting from such special studies are seldomly shared with other researchers. In summer 2012 I realized that this is a shame, really. So I  started to share  my
data by making them available.

Why collecting this data?
I started the audiorecording in 2008. In 2005 the population in the Peene valley suddenly declined and except for a local fisherman and me, nobody really noticed (= cared). Looking back now the cause was probably floods combined with deep snow. These things may happen every now and then, but what if it had been a disease? Since then I wanted to keep a close eye on my wild neighbours, feeling that the official monitoring being carried out was not frequent and efficient enough.
So I started to monitor (map) the territories regularly with the help of some more nature friends
(Map will follow as soon as possible).
Also, to get more details on “how the animals are doing”, part of the approximately 110 territories  were regularly checked by ”eavesdropping”. You can hear if the population is in a healthy state. Healty and happy beavers breathe freely and have some kits in their lodge. But these recordings have the potential to tell us much more about the life of the beavers. I only searched for signs of diseases and reproduction in this data, but feel free to do more with it!

Autor and thanks to others
All recordings where made on my own initiative (and costs) with all necessary permits. But it could not have been done without the help and knowledge of following persons.
My dear beaver friend Werner Sykora turned the first beaver microphone, that was tested 1988 from Prof. Zyrowski and Karl-Andreas Nitsche (Castor Research Society, Dessau), from a big heavy job (tape recorder with 8! car batteries) in a very advanced small piece of technique fitting in one hand. Sykora was a smart technician with a feel and a lot of patience for beavers and always in for a good joke. The microphone that Sykora developed is something special. It allows to study the beavers in their lodges without disturbing them. I am grateful for his microphones and alle the other things he taught me.
Very grateful I am also to Dr. Wölfel (LUNG MV) for his trust he showed in giving me a permit to start this kind of beaver research in Mecklenburg-Vorpommerania.
Dr. Heidecke (University of Halle) together with many others helped the beaver to return in this region. In the 1970s they brought some families of Elbe-beaver (Castor fiber albicus) from the Mulde to the Peene valley. Their aim was to start a “spare population” of this species, as the animals in the river Elbe where the last in Germany. The plan worked. Nowadays the Elbe-beaver has turned back in the Peene and other water systems in the region. So a spare population was started and at the same time other profits for nature and people where induced.
Without beavers the Peene valley would be much less attractive for many animals and plants (and tourists). Where beavers dig and build, otters find good places to hunt and hide. Where beavers cut trees and bushes there is plenty of space for flowering herbs and warm sunlight attracting butterflies and all sorts of other animals (until the shrubs regrow and the “game” starts all over again.).
The beavers also make business for some tour operators. Unfortunately this is not done in a very sensible way causing all sorts of negative impact on beavers and other animals and their habitat.
Peter Lindemann (Haus Biber & Co., Parchim) was probably the first in M-V to recognize such problems with tourism in beaver biotopes and to do something about it. In 2002 he managed to set up
‘Golden rules for tourism in the beaver biotope “Warnow valley”. Unfortunately he died a few years later, but these rules are still working well and respected on the Warnow.
It would be very nice and very wise if
these easy rules could also be respected by the companies doing their business in and about the “Pommeranian rivers”. They do not appear to realize that they are slowly destroying their own business and our nature. And that is why I can not allow them to use these recordings.
Last but not least: Thank you beavers! Even though you didn’t have a choice, it is really special to listen to you.

Using this data, copyright und some thoughts.
It is not allowed to use the sounds, pictures or films found on this site for commercial purposes. It is for example not allowed to use them on websites that promote tourism (see above).
But all others may store, copy, use, change and share these data in any way they want, as long as nature and beavers profit from it and the source ( is mentioned.
Die Urheberrechte und das Copyright liegen ausschließlich bei Geranda Olsthoorn.

Some toughts. Knowing that the belly noises of the beavers are very funny (because recognizable), it is quite likely that some people will make fun out of it. Well, may it be so. But even funny noises sometimes tell serious stories about what we do with our beavers:
Extraordinarily many “beaver bubbles” can be heard on the recordings from a lodge on the
Swinow (Dezember 2008).  Here it was tried to get rid of the beavers by removing all bushes (i.e. the beavers food) even in a nature reserve. So what happened is, that they (the beavers) started to feed on the leaves of rapeseed which was easy accessible that winter on a field right beside the burn. As rapeseed is just another  kind of cabbage, the beavers had quite some reason to ”ventilate” their distress.
In January 2012 it was too quiet in the lodge. No kits, just the pair. Well, my recordings do not answer the question as what happened to the young ones, but it is a fact that the dams that protected this families lodges where destroyed over and over again. Even if it is a legal offence to do so and even though I talked about it with the officials and the guys doing this more then once. So you see, listening to your beavers is not always fun.
But then, most of the time the recordings are just great, touching and good fun. I’m sure you’ll like their voices and noises as well.

How to download and analyse these data
Before opening or downloading the files please notice that they are very large and can, depending on your internet speed, take a lot of time to start or download.
All recordings are in “wma-format” and you’ll find them on the page  ”alle Daten / all files”.
On the site with
examples you’ll find a selection of typical beaver sounds that are only a few seconds long.
“raw” recordings are normally approximately 26 hours long. You’ll find them on the page ”alle Daten / all files”.

Depending on what your computer normally does with wma-files, when you “klick” the file it will open/play the file or open a window that gives you the possibility to open/play or save/download the file. If a left-click does not open the file, then try a right-klick. In the window that then opens, you can now save the file by choosing “save link as...”. Once downloaded on your computer, you should be able to open the file with any audio programme. If you are willing to seriously analyse these data, I would advice you to keep to my following routine:
Save the file in the map “beaver audio” on your computer (or an external harddisk). Make different maps for all different territories/families. I will also stick to this family-names in future. Depending on how much time I have, the family will be visited once a year or at least every second year.
Cut the “raw file” in pieces of 5 hrs (or 2 hrs if the recording was in XQ-stereo quality). To cut you might for example use “ASF-Tools” (freeware from Internet). I name the different cuts as follows: familyxxxcut0-5, familyxxxcut5-10.
Then analyse the cuts for example with “Nero WaveEditor” (you can buy it on the internet). You will find some
examples here. When you save a copy of an interesting part, the easiest way is to give the time your copied sound started in the file name (familyxxxcut0-5-0235).

Questions and feedback
If you find any methods to make the analysis easier or if you have a question I’d be happy to receive your mail. Maybe you let me know what you did or found out with the data. I will always try to answer, but please allow me some time to do so.

Autor and Lodge-sites
All data are collected and so all data are owned by Drs.Geranda Olsthoorn. For obvious (protectional) reasons I will not give the exact locations of the lodges. But I am working on a map where you can find the territories of the beavers, that will then be published on the site “Reviere / territories”.

The use of the Beaver-Audio-Project (a short review): recording <-> protection
Six years after recording my first beavers I would say it is a very useful method. With the recordings it is fairly easy to get good data on the health and reproduction of the families without seriously disturbing them. So I reached my aims, it works well.
Absolutely unexpected, but just as valuable, is that with the aim to record the beavers I also documented the beauty and richness of the nature in the Peene valley as well as the things threatening it. Unexpected also was how much all these sounds go under the skin. They make adults and children laugh, think, listen. For me this was another reason to share my data and give the beavers a voice.
An extremely sad but clear example for the power of sounds is a recording from Bio-Acoustician Dr. Bernie Krause.
He recorded a male beaver that lost his family as their dam was destroyed and his female and cubs were killed (Link: Hearing this, there can be no doubt, that beavers do grieve when loosing it all.
Also in our region where beavers are protected by (European and German) law, dams and burrows are destroyed and beavers killed. The recordings also document other problems the animals have to deal with. Waves (from all sorts of boats) rolling in and out of the core of the lodges slowly taking them apart and endangering the youngest beavers that cannot swim properly yet, roosting cranes disturbed by a party-firework at the end of summer, or the voices of paddlers reaching deep into the lodges and disturbing the animals are some of them.
Reasons enough to keep an eye and and ear on the beavers in the Peene valley and share my data here with you.

A pest, a treat or on a threath? (because people keep asking me....)
Some people in our region talk of our beavers as a pest. Well this is just not right. Beavers can be a bit of a nuisance as they naturally do things that we do not like. Just one beaver can fell your favourite apple tree or dam a burn and swamp your meadow. So even if there are few beavers around, it may feel as if there are loads of them. Now it is a fact, that only few beavers live in our environment. In the Peene valley between the Lake of Kummerow and the Isle of Usedom there are aproximately three to fourhundred. The ‘hidden’ problem is, that they originate from only a few parents. This makes the population vulnerable. When a disease turns up, the risk that they will all get ill is large.
When there are no wolves to eat the beavers, they do regulate themselves. They do so by being very aggressive towards their neigbours and all other unknown beavers. Only once a year 1 to 3 kits are born. When they are about two years old they leave their family. A large amount of these youngsters get killed by the inhabitants of the strange territories they have to cross when looking for an own place to live. Once a beaver has found himself a suitable territory and a partner, it will stay there, become its own kits and can easily reach an age of 15 to 20 years old.

Summer 2019 the State of Mecklenburg-Vorpommerania is trying to install a law that wil make it easier to kill beavers at sites where they are not favoured and destroy the dams. What should i say. I hope it will not be done that way. There are alternatives and there still are not that many of them.
It would be nicer to declare the “beaver wet meadows” as landscape elements in the farmers land so the can still be subsidized in the agri-environmental schemes like is done for example with Trees. The same can be done for bits of (re)weted forest. It would cool the discussion a lot down and beavers then could together with farmers and foresters make a more diverse landscape. Considerund the terrible droughts in 2018 and 2019 it might even be a blessing for the landscape and the landowners.


Some beaver sounds (examples)
All files