Beaver (Castpr fiber L., Castoridae) management in Bavaria

8 Pages·2003·0.71 MB·English

by  Schwab, Gerhard

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Beaver (Castor fiber L, Castoridae)
management in Bavaria
VON G. SCHWAB & M. SCHMIDBAUER
Abstract Zusammenfassung
Beavers were exterminated in Bavaria in
Biber {Castor fiber L, Castoridae)-
1867. The reintroduction, conducted by the
Management in Bayern
„Bund Naturschutz in Bayern e.V." between
Biber wurden 1867 in Bayern ausgerot-
1966 and the late seventies, was very suc-
tet. Die Wiederansiedlung unter der Füh-
cessful: the present beaver population in
rung des „Bund Naturschutz in Bayern e.V.",
Bavaria is estimated at more than 6.000 in-
die zwischen 1966 und Ende der 1970er Jah-
dividuals, and it is still growing and expand-
ing into its former range. re stattfand, war sehr erfolgreich. Die derzei-
tige Biberpopulation in Bayern wird auf über
This success was paralleled by a growing
6000 Individuen geschätzt, nimmt weiter-
number of conflicts between beavers and
hin zu und breitet sich auf das ursprüngliche
human land users in the densely settled and
Gebiet aus.
intensively used Bavarian landscape.
Zeitgleich mit diesem Erfolg stieg auch
Beavers fed on crops, beaver dams flooded
die Zahl der Konflikte zwischen Bibern und
forests, pastures and basements, beavers
Landnutzern in der dicht besiedelten und
digged their burrows under roads, fields and
intensiv genutzten bayerischen Landschaft.
high water dikes, and some of them felled
Biber fressen Feldfrüchte, durch ihre
apple trees in gardens. During the 1980s un-
Dämme werden Wälder, Viehweiden und
til the early 1990s, the beaver conflicts es-
Keller überstaut, sie bauen ihre Röhren un-
calated, less because of the real world prob-
ter Straßen und Felder, in Hochwasserdäm-
lems, but more because politicians and mass
men und einige fällen Apfelbäume in Gär-
media abused this conflict between nature
ten.
conservation and land owners for personal
In den 1980er Jahren bis zu Beginn der
gain.
1990er Jahre eskalierten die Konflikte, es
Taking a closer look at beaver-human- waren keine weltbewegenden Probleme,
conflicts, we found, that almost all conflicts aber Politiker und die überwiegende Mehr-
root in the overuse of landscape by man: zahl der Medien missbrauchten diesen Streit
beaver conflicts happen mainly in a narrow zwischen Naturschutz und Landnutzern zur
strip along the river banks. Where man has persönlichen Profilierung.
left some space to the rivers, there are only Betrachtet man diese Konflikte zwi-
very few conflicts with beavers. Such unused
schen Biber und Landnutzern näher, kommt
areas are not only important for beavers and
man zu der Erkenntnis, dass die Hauptursa-
other plant and animal species, but more and
che in der Übernutzung der Landschaft
mainly for man himself (e.g. for protection of
liegt: Der Großteil der Probleme liegt in ei-
water and prevention of floods).
nem schmalen Uferstreifen. Ließe man die-
Key words: beaver, Castor fiber, man- sen Streifen ungenutzt, wären die Konflikte
agement, Bavaria auf ein Minimum reduziert. Solche unge-
nutzten Bereiche wären nicht nur für den
Biber und andere Tier- und Pflanzenarten Denisia 9, zugleich Kataloge
der OÖ. Landesmuseen
wichtig, sondern vor allem auch für den Neue Serie 2 (2003), 99-106
99
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Menschen selbst, z. B. für den Wasserschutz In Bavaria, where a successful beaver
und zur Verhinderung von Hochwässern. reintroduction between 1966 and the late
1970s yielded an still expanding population
Introduction of more than 6000 animals, these conflicts
remained unsolved for many years and
Beginning in 1996, 30 years after
caused increasing disputes between nature
beaver's reintroduction, a beaver manage-
conservation organisations and agencies and
ment was developed with the goal to keep
land users and their associations, the top de-
and promote the beaver in Bavaria by cre-
mand being the complete re-removal of
ating and improving acceptance for
beavers from cultivated landscape.
beavers and their activities. The develop-
ment of the beaver management was fund- In this paper we give a short overview of
ed by the European Community, program the history of beavers in Bavaria and the
LEADER II, and local authorities; the im- problems they are causing and present then
plementation is funded by the "Bayerische the beaver management which was devel-
Naturschutzfonds" (Bavarian State founda- oped in the last years to solve the problems
tion for the protection of Nature), and the and - in the long run - to use the beaver as
"Bund Naturschutz in Bayern e.V." (a a flagship species for the restoration of river-
NGO). side forests.
The key to the future of the beavers in
Bavaria are the landowners, on whose The Beaver in Bavaria:
properties the beavers are living. We consult a short history
these landowners in case of conflicts with
beavers and assist them in applying for fund- Historic distribution and extinction
ing for protective measures; we also try to Beavers were a common species in
convince them to give up agriculture or Bavaria up to the 16'h century. Their distri-
forestry and to lease or sell the land to state bution over almost all of Bavaria, with ex-
agencies or private nature conservation or- ception of the Alps and the higher areas in
ganisations. We also do public relations work low mountain regions, is documented by
on a broader scale to inform the general pub- about 300 names of villages, streams or
lic about beavers, its benefits for wildlife, landscapes (ZAHNER 1997). The decline of
conflicts and the solutions for the future of the beaver population began locally in the
the beaver within the beaver management. 17th century, expanded through the 18 cen-
Another important issue is the implementa- tury and ended with the killing of the last
tion of beavers and its habitats in long-term Bavarian beaver in 1867 (WEINZIERL 1973).
landscape planning, as this is one of the best
The reason for the extinction of the
ways to reserve areas for beavers and river-
beaver in Bavaria was over-hunting. They
side forests from an early stage.
were hunted for meat, for their valuable pelt
Beavers (Castor fiber L.) are very capa- and for castoreum, which was widely used as
ble of modelling the land they live in (e.g. remedy. Habitat changes, esp. the regulation
DJOSHKIN & SAFONOV 1972, NOVAK 1987): of the major rivers and large bog areas had
beaver dams flood and wet large areas, their only an indirect influence by allowing an
burrows and dens increase the structure of easier access for hunters into the last re-
river banks, and the cutting of trees creates maining beaver territories (ZAHNER 1997).
openings in the riverside forests. As positive
as these activities are from a nature conser- Reintroduction
vation point of view, as problem causing Reintroduction of beavers in Bavaria
they are, when beaver express them in a cul- began in 1966, 99 years after the last beaver
tivated landscape used by man: beaver dams was killed. Until the late 1970s, the "Bund
flood corn fields, machinery and people may Naturschutz in Bayern e.V.", the major na-
fall into beaver burrows, beaver burrows ture conservation NGO in Bavaria released
threaten functionality of dikes, the last trees about 120 beavers in several different places
disappear from the rivers. (WEINZIERL & FROBEL 1998). The beavers
100
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came from wild and captive source popula- .j.....:....i....^.M....i~;^.. i.....:Vvi...Ji JL.IfA....: :....: ..A \.-JSl.... •...
.1.... \ I j
j...
tions in Sweden, Finland, France, Poland
i . i
and the Sovjet Union (WEINZIERL 1973). i H•Is < v/r
Reintroduction was permitted by the Bava- AA(A
rian Ministery for Forestry and Agriculture, iAr* A
5
as beavers were listed as game species at this A \
h
time. I \ x A A AH
n AAAIA,
beavIenr s twheer e mtriadpdpleed oinf ththee c en1t9r8a0l sD, asnoumbee U rV Akm i A •\ AAjAAA A/A£
area in Bavaria and relocated to the Inn ••# \ 4? A *£AT
C
and Isar river (SCHWAB et al. 1994). In A AAA$AA •
f
northern Bavaria, beavers immigrated in the iAA AAA AAA V
4
early 1990s from a reintroduced population \AAA AA AA AA A
•
of East German beavers in Hessia. (SCHWAB t } AAAA A A A A" AAA"
et al. 1994). i! Ji AAAAIL AA A A AEAA A \ A
h. A \ A AA A AA A A. s
_i 1 »
Present status of the Bavarian beaver (AA AA' AAX A
population i \ A-^ AA AA A A
1 X« AA AAA A A-
During the first decades after reintro-
t AAAJ AAJA A AA
1
duction, the Bavarian beaver population —• A /S£ AAAf AAAA A —i /
grew scientifically almost unattended. The
>AAAAAA AAA /
i • V
first state wide population estimate based > A A4 A AA A
on a poll and field work was conducted / A /
from 1988 to 1992. At this time, the popu- i M —
lation was estimated at about 800 to 1200 1 ( A —
i
animals (SCHWAB et al. 1994). In 2002, we A
estimate the beaver population in Bavaria h ij A
to more than 6000 animals in 1500 r ^^ J "\
£ {
colonies. The beavers have reoccupied a If Aj> %, / ——
•—
large part of their former range (Fig. 1,
Regierung von Unterfranken 2001), al- i.....
though colony density is low at the borders
small drainage ditches in extensive farm Fig 1. Beaver distribution in Bavaria.
of the present range. (Regierung von Unterfranken 2001)
lands, they digged their burrows in the
banks of sewage treatment ponds or under
The Bavarian beavers have also changed
roads, and they used drainage pipes under
their legal status since reintroduction. They
airport runways as lodges. In these areas,
lost their status as game species and are now
where beavers and man used the same land,
a strictly protected species by European and
an increasing number of conflicts between
German laws (HIMMELSBACH 1994).
beaver and man started in the 1980s.
Beavers in a cultivated land- The "real world" problems
scape: conflicts and solutions
Beavers feed on crops
During the beaver-free century in
Beavers have easily accepted crops, esp.
Bavaria, man had heavily altered the Bava-
corn, sugar beets, wheat and rape as food.
rian landscape: he had regulated rivers, he
The direct loss of crops is mostly low and ac-
had changed riverine forests into corn fields,
cepted by farmers. More important than the
and he had meliorated bogs into spruce
damage to crops are damages to the creek
plantations. Beavers, however, did not care
banks by beaver slides, and thereby in-
much about these changes in their habitats.
creased erosion, beaver dams and channels
They are a species with a very high adapt-
build by beavers for easier access into a field,
ability and low habitat requirements: some
and beaver burrows under fields.
water to swim and some plants for food.
Beavers began to settle and build dams in
101
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Beavers cut trees a complete loss of the fish stock (SCHMID-
BAUER 1996, unpubl.).
By cutting trees for winter food or as
building materials, beavers can cause a num-
ber of conflicts. Beavers cut not only Solutions for
"worthless" willow or aspen, but also eco- beaver-man-conflicts
nomic valuable species (e.g. oak or acorn),
they debark spruce and fir, feed on fruit- The activities of Bavarian beavers re-
trees in villages and can clear cut expen- main almost exclusively within 20 m of the
sively planted restoration areas. banks of rivers or ponds (SCHWAB et al.
1994). Problems only arise when humans
The cutted trees can create further pro- use this small strip of land as well. There-
blems, especially if they lie in the water and fore, the lasting solution of beaver-man-
impair the drainage of high water, impede conflict lies in the removal of human land
access to fields and meadows, block streets us in this range and the recreation of river-
or railroad tracks, damage power lines, or side habitats. These unused areas are not
damage small hydroelectric power plants. only important for the beaver and many
other species, but mainly for man himself.
Beavers build dams
They buffer fertilizer and pesticide drainage
Bavarian beavers build dams mainly in from the adjoining agriculture, and more
small creeks and drainage ditches with in- important, they can be used as buffer areas
sufficient water depth. The backwater of to protect villages and towns from floods.
beaver dams can flood forests and kill eco-
There are also a large number of techni-
nomic valuable trees (e.g. spruce), or flood
cal measures to prevent or minimize beaver
agricultural fields, roads and basements of
damages on local spots (e.g. HEIDECKE &
houses. Mill creeks, fish ponds and water
KLENNER-FRINGES 1992, SCHWAB et al.
treatment plants can overflow due to beaver
1994). Gratings, sheet-pile walls or gravel
build obstacles. The increased ground water
layers prevent undermining of dams and
level can clog up drainage pipes, increase
roads (DVWK 1997), electrical fences keep
erosion of soaked banks and destabilise rail-
beavers out of areas, wire meshs and chemi-
road tracks.
cal repellents protect trees, culverts in
beaver dam lower the impact of flooding,
Beavers dig holes
and a free running dog keeps beavers from
The digging activity of the beavers re- eating roses in gardens.
presents the biggest problem in the cultivat-
If protective measures are to expensive,
ed landscape. The subterranean tunnels
or take a long time to be implemented,
reach several meters into the ground. If there
beavers are trapped and relocated to other
is any use of these areas (agriculture, roads,
areas (SCHWAB & SCHMIDBAUER 2001).
gardens), there is a permanent danger for ve-
hicles or people falling into the beaver tun- Compensation for damage caused by
nels and being damaged. Beaver tunnels can beavers is not possible by state agencies, as
also compromise the integrity of high water there is no damage compensation for any
dikes and threaten the dams of mill creeks. free living wild animal in Bavaria (except
Fishponds and water treatment pools can be some game species). There is, however, a
drained as a result of beaver tunnels. In small privately based fund from the Bund
drainage ditches and ponds, the increased Naturschutz in Bayern e.V, which allows
sedimentation can be an additional problem. compensations as a first step to make a
landowner more willing to accept long term
Beavers disturb fishes solutions (WEINZIERL & FROBEL 1998).
Beavers disturbing fishes is a special sea-
The problem behind the problems
sonal problem in fish hatcheries. In ponds,
where fishes are kept in high densities for The solutions for conflicts between
wintering, beaver activities keep the fishes beaver an man were known in Bavaria since
moving. This results in weight loss and the early 1990s, but implementation of solu-
higher oxygen consumption and may cause tions was between slow and not at all. This
102
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had several reasons. Personnel at the local as conflict between beaver biology and ex-
nature conservation agencies was not isting habitat structures, and less as a prob-
trained on dealing with a strictly protected lems of the human dimensions associated
"problem" species and did not have the time with and behind it.
to act quickly in case of a conflict; and if
Therefore another way of dealing with
they found the time to act, there was almost
beaver conflicts was established by building
no funding for damage compensation or for
a beaver management in Aldo LEOPOLD'S
supporting preventive measures.
(1933) sense: manage the people not the
For farmers, under heavy economical beavers. Manage the people, from farmers
pressure from politics and the international who have the problems, to politicians who
markets, the beaver was often used as scape- make the laws, to get the land to set aside
goat: if you can not do anything against the for nature. The beavers, and all the other
European Community, then hit at least the species, will then do the rest - as they did for
beaver. They felt, that everybody else was million of years without being managed by
having the benefits of the beavers (from humans.
creating habitats to the pure pleasure that
he his back in Bavaria), and that they them- „Evolution" of the beaver
selves were the only ones who had to pay management
the bills. This exaggeration, on the other The first steps towards this beaver ma-
side, made nature conservation people un- nagement in Bavaria started in 1996. A bio-
derestimate the real problems and not tak- logist from the Munich Wildlife Society
ing the land users serious. So, even in severe (Wildbiologische Gesellschaft München
cases, with damages of thousands of EUROs, e.V), commissioned by the Government of
no trapping permits for beavers were issued. Upper Bavaria (Oberbayern) consulted
farmers and landowners in the county of
Last not least, mass media and politi-
Neuburg-Schrobenhausen in Central
cians used pushed this „classic" conflict be-
Bavaria to solve their beaver problems and
tween nature conservation and farmers for
helped them to find funding for compensa-
their own advantages, turning every beaver
tion and protective measures. Although not
burrow in a corn field into a deadly thread
all cases could be solved (SCHWAB 1996, un-
for farmers, just to make the headlines.
publ.), landowners showed that they were
So, 30 years after the first reintroduction, willing to accept the beaver, if they got ad-
Bavarian beavers had grown into a schizo- vice, help and financial support in case of
phrenic species: they were a holy cow for problems. On the other hand, nature con-
some nature conservationists, and the equi- servation organisations learned, that there
valent of the medieval rat plague for the are some cases, where beavers cause intoler-
farmers. Some farmers organisations even able damages and had to be removed by
wanted the beaver completely removed from trapping.
the cultivated landscapes in Bavaria, which
In northern Bavaria a similar approach
means (as Bavaria is almost 100% cultivated
was undertaken to solve the conflicts with
landscape) nothing else as the re-eradication.
beavers in fish hatcheries (SCHMIDBAUER
1996, unpubl.) in the district of Oberpfalz. In
Beaver management: the same year, the Bavarian State Ministery
the Bavarian way for Environment Protection (Bayerisches
Staatsministerium für Landesentwicklung
The disparity between real beaver con-
und Umweltfragen) issued guidelines for na-
flicts and their presentation in the media,
ture conservation agencies on problem solu-
and the disparity between possible solutions
tions and financial support programs (BSTM-
and the amount of implementations
LU 1996, unpubl. (updated 1999)).
showed, that existing administrative and or-
ganisational structures were not suitable of The results of the first two projects in
solving the beaver conflicts. This was partly 1996 encouraged the agencies involved to
due to lack in manpower and money, but al- establish a beaver management for all of
so because beaver conflicts were mainly seen Bavaria. This was done in two projects with
103
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originally somewhat different main focuses. Training and organising "local
One project, running from 1998 to 2001 was beaver consultants"
funded by the European Community,
Bavaria is just too big to be adequately
LEADER II Program, and 5 counties in cen-
covered by the two beaver managers work-
tral Bavaria; it's main focus was to develop
ing for the Bund Naturschutz in Bayern e.V.
the organisation and structures for the
A network of individuals from the local
beaver management (SCHWAB 2002, un-
public shall support the nature conservation
publ.). The other project, running from
agencies and the beaver managers in con-
1998 to present is funded by the "Bayerische
sulting, implementing solutions and moni-
Naturschutzfonds", a state guided grant, and
toring the beaver population.
the "Bund Naturschutz in Bayern e.V.", the
major nature conservation NGO in Bavaria;
Monitoring the beaver population
it's focus is on the Bavarian wide implemen-
Data quality on beaver's area of distribu-
tation of the beaver management (SCHWAB
tion and population size is highly variable
& SCHMIDBAUER 2002, unpubl.).
within Bavaria. A monitoring system would
help to recognise potential conflicts earlier
The job description for beaver
and to act better in advance. The monitor-
management
ing system will be set up in the next years
The first activities in 1996 had mainly a
based on the local beaver consultants.
fire fighter function: solve the problems
which had been present for years. This is still
Mediating between authorities,
a major part of the work, but for the future,
NGO's and individuals
the activities will shift more towards preven-
One of the most important jobs is to be
tion of conflicts. All beaver management ac-
a mediator between the parties involved, as
tivities are conducted in close co-operation
many "beaver" conflicts have their roots in
with nature conservation agencies, especial-
completely different and much older quar-
ly on the county level. Beaver management
rels between a farmer and a nature conser-
is not a replacement, but a consulting help
vation agency.
for these agencies. The main activities of the
beaver management are:
Public relations work
Consulting in case of problems and Many beaver conflicts arose from a lack
helping in implementing solutions of knowledge (e.g. fishermen believing that
beavers eat fish, or farmers fear that beavers
The beavers are still expanding their
have the same reproductive rates as rats).
range in Bavaria, and in spite of all preven-
Information on beaver biology, conflicts, so-
tive measures, there will always be individual
lutions and management is therefore a vital
conflicts. Here it is necessary, to consult the
part of beaver management.
people involved as quick as possible to mini-
mise and prevent negative attitudes against
Develop a use for "surplus beavers"
beavers. It is also necessary not only to con-
sult, but also the help people in implement- So far, most of the beavers trapped in
ing solutions (e.g. protecting trees or crops). Bavaria could be used for reintroduction pro-
grams, mainly in the Danube countries in
Introducing beavers in all habitat Eastern Europe (SCHWAB & LUTSCHINGER
related planning systems 2001). These programs will be finished with-
Preventing conflicts is better than sol- in the next couple of years; so it necessary to
ving conflicts. The best and least expensive develop a further use for these beavers, con-
way to prevent beaver conflicts is to take sistent with existing laws and within the ac-
beavers and preventive measures against ceptance of nature conservation organisa-
beaver damages into account in all planning tions.
systems working in potential beaver habitat.
This will be done by training the personnel Gett mmoonneeyy
in agencies and companies responsible for BBeeaavveerr mmaannaaggeemmeenntt,, aannda eessppecially
this plannings. buyiinngg llaanndd ccoossttss mmoonneeyy.. OOnnee mmaajjoorr task is
104
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therefore to find the financing for the ma- areas, and new peoples will be involved.
nagement and the restoration of riverside Therefore, beaver management as described
forests. above will also be extended in the foresee-
able future.
Summed up, the task of the beaver ma-
nagement is to bring the beaver back in the It will take it's time, before beavers will
heads and hearts of the people, who simply be accepted by most people as what they are.
forgot how to live with this fascinating crea- Not a holy cow and not the reincarnation of
ture and to bring fonvard what the beaver medieval rats, but a fascinating species that
stands for: the recreation of riverside forests, creates and shapes landscapes for the bene-
not (only) for beavers and other species, but fits of many species, including man himself.
also for man himself.
The urgent need for what's behind the
beaver management was demonstrated in
Organisation of the beaver
August 2002 (and earlier in May 1999).
management
Floodings in Bavaria caused damages of
Beaver management in Bavaria is a joint
hundreds of millions of EUROs. If only part
project between NGO-operated beaver
of this money would have been available
managers and state agencies. Presently,
during the preceeding years to buy "beaver"
there are two beaver managers in Bavaria,
land along the rivers, a lot of water could
working for the "Bund Naturschutz in Bay-
have flooded these lands, and a lot of houses
ern e.V." Funding is provided by the "Bay-
along the Danube would have stayed dry.
erische Naturschutzfonds". In an increasing
Not only in August 2002, but also in the fu-
number of counties, the beaver managers
ture floodings to come.
are supported by the so called "local beaver
consultants". These are people form the lo-
cal public (hunters, farmers, fishermen, na- References
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hinderung von Schäden durch Biber. — Un-
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© Biologiezentrum Linz/Austria; download unter www.biologiezentrum.at
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heim. Schlussbericht 2001. — Unpubl. report,
III + 46pp. + appenices.
SCHWAB G. S G. LUTSCHINGER (2001): The return of
the Beaver to the Danube watershed. — In:
CZECH A. & G. SCHWAB (Eds.), The European
Beaver in a New Millenium. Proceedings of 2nd
European Beaver Symposium, 27-30 Septem-
ber 2000, Bialowieza, Poland, Carpathian
Heritage Society, Poland, 47-50.
SCHWAB G. & M. SCHMIDBAUER (2001): The Bavarian
Beaver-Reextroductions. — In: CZECH A. & G.
SCHWAB (Eds.): The European Beaver in a New
Millenium. Proceedings of 2nd European
Beaver Symposium, 27-30 September 2000,
Bialowieza, Poland, Carpathian Heritage Soci-
ety, Poland, 51-53.
SCHWAB G. & M. SCHMIDBAUER (2002): Jahresbericht
2001. Tätigkeit als Biberberater. — Unpub-
lished annual report, 19 pp. + Appendix.
SCHWAB G., DIETZEN W. & G. v. Lossow (1994): Biber
in Bayern. Entwicklung eines Gesamtkonzep-
tes zum Schutz des Bibers — In: Bayerisches
Landesamt für Umweltschutz (Ed.), Biber.
Schriftenreihe des Bayerischen Landesamtes
für Umweltschutz 128 (Beiträge zum Arten-
schutz 18), München, 9-44.
WEINZIERL H. (1973): Projekt Biber. — Stuttgart,
1-63.
WEINZIERL H. & K. FROBEL (1998): Auf zu neuen
Ufern! Die Wiedereinbürgerung des Bibers in
Bayern. — Nationalpark 100: 46-50.
ZAHNER V. (1997): Der Biber in Bayern. Eine Studie
aus forstlicher Sicht. — Bayerische Lan- Authors' adresses
desanstalt für Wald und Forstwirtschaft, M. Sc. Gerhard SCHWAB
Freising, 1-63.
Wildbiologe
Hundldorf
Deggendorfer Straße 27
D-94553 Mariaposching
Germany
[email protected]
Dipl.-Biol. Markus SCHMIDBAUER
Jahnstraße 16
D-93093 Donaustauf
Germany
[email protected]
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