THE HAMSTERS OF ALSACE

Transcription

THE HAMSTERS OF ALSACE
THE HAMSTERS OF ALSACE
A Threatened Symbol of
Biodiversity
In pockets of low-lying farmland in France, a small
rodent is the subject of much controversy, stirring
up tensions between politicians, farmers and
conservationists.
The rodent in question is the Black-bellied hamster. Previously considered a pest, this species has
been formally protected by ministerial decree since
1996, along with the wolf, bear and lynx.
Yet, despite this protection the species has been
in steep decline since 2010, and the disappearance
of this little known species would have a dramatic
impact on the structure of the local ecosystem.
All images © Eric Baccega / naturepl.com
The Black-bellied hamster (Cricetus cricetus), also known as the European or
Common hamster, is the only member
of the Cricetus genus.
They live a solitary nocturnal or crepuscular life in the wild, and inhabit a
complex system of burrows which can
reach depths of 2 meters.
They are much larger than their more
familiar relative the Syrian hamster,
growing to lengths of 25-30cm and
weighing up to 400g.
They are fiercely territorial and each
burrow is occupied by one individual,
with the exception of a mother and her
young.
The hamsters act as an indicator of
good ecological health, as their presence not only provides a food source
for foxes, eagles and other predators,
but also demonstrates that the habitat
is suitable for other small mammals
and birds such as partridge and polecats.
Distribution & Habitat
Native to large areas of Eurasia,
the Black-bellied hamster ranges
from Belgium to the Altai Mountains in Russia.
Originally favouring a habitat of
fertile steppe and grassland, as
human activities encroached on
their range hamsters have successfully spread into man-made
environments including meadows, croplands and field edges.
Globally the population of Blackbellied hamsters is not considered to be vulnerable, yet locally in
areas of Belgium, France and Germany populations are critically
endangered.
Deep ploughing and early tillage also pose
threats to hamsters’ survival.
Agricultural Conflict
Many European populations, including that of the Alsace in
France, are now small and fragmented due to historical persecution. The threat to this population is further compounded by
changes in agricultural practice.
Hamsters prefer habitat created by sowing a mix of crops such as
wheat, barley or oats, and perennial legumes such as alfalfa
(lucerne). The maize monoculture, which now occupies 80% of
the agricultural land in the Alsace region causes a number of
problems.
Maize provides very little cover in spring which is when the
hamsters are breeding and at their most active, which
leaves them very vulnerable to predators. Maize
monocultures, while easier for farmers
to manage and harvest, reduce the
amount of habitat suitable for
hamsters.
Lucerne fields are ideal habitat for
hamsters, but are no longer
financially viable for farmers.
The evolution of ever more efficient
techniques for cereal cultivation
also impacts on the hamsters’ survival, and could lead to local extinction.
Modern machinery leaves a greatly
reduced stubble layer in autumn
meaning there is less food and cover
for young when they are born.
In 1993 the Association for the Protection of Wildlife
(L’association Sauvegarde Faune Sauvage, SFS) was
created in Elsenheim in the Lower Rhine Valley.
The Black-bellied hamster was declared a protected species by the French government and they established a
program to rear, breed and reintroduce black-bellied
hamsters into the wild.
However by 2009 it was still considered among ‘the
most endangered mammals in Europe’ by the European Commission because the number of burrows
continued to decline, from 1,167 in 2001 to 161 in
2007, a trend which continued until 2009.
In 2011 the Court of Justice in Luxembourg ruled that
France had failed to protect the Black-bellied hamster.
The court said that if France did not adjust its agricultural and urbanization policies sufficiently to protect
the Black-bellied hamster, the government would be
subject to considerable fines of as much as 800,000
Euros per day.
In August 2012 a ministerial decree was issued which
required that a radius of 600 metres around each burrow located be managed in such a way as to be suitable
for hamsters to breed.
This ruling was not well received by local politicians
and even the SFS feared it may lead to the mass destruction of hamster burrows, in order to prevent future urban development projects being blocked.
Breeding Centres
The SFS now runs 3 breeding
centres which are dedicated to
the breeding and reintroduction
of Black-bellied hamsters into
the Alsace region, with the aim
of reintroducing approximately
500 hamsters per year.
Breeding Programme
The females are very aggressive and must
accept a male for mating. As a precaution,
the male is kept in a cage before they can be
properly introduced.
Under the watchful eye of scientist Celine
Boulage, the hamsters breed once before
being released back into the wild.
This system has proved successful as a reproduction rate of around 30% is achieved.
The female gives birth to a litter of 5
young on average. Gestation lasts 21 days,
and the young are weaned 21 days later.
The babies are born deaf and blind. On their second day they show black pigment on their back.
By the fifth day the back has a light covering of
dark fur and black hairs appear on the belly.
2 days old
5 days old
Reintroduction
Once the hamsters are old enough they are released by ONCFS (National Office for Hunting
and Wildlife).
82% of the hamster population is concentrated in
five communities situated in the Lower Rhine.
Martin Klipfel, Mayor of Grussenheim, shown
with Jean-Paul Burget (President of SFS),
supports the hamster project, but understands
the frustration felt by farmers who find their
construction projects blocked due to the presence of hamster burrows on their land.
On 8th June 2013, 115 hamsters were released in 3 hectares of standing wheat, which will not
be harvested, to allow the hamster reintroduction the best possible chance of success.
Christian Schmitt is a local farmer who owns around 100 hectares
of land at Elsenheim, where he grows maize, lucerne and wheat.
He is taking part in the hamster reintroduction project and holds
one of the 3 breeding centres on his land, and certain of his fields
are dedicated solely to the hamster reintroduction.
The standing wheat, which will not be harvested, will allow the animals to find food and shelter from spring until autumn. In return
for his co-operation in the reintroduction project, he receives compensation from the government.
Monitoring Wild Populations
Monitoring the existing population and
success of the reintroductions is another
aspect to the work done by SFS, and they
work closely with the ONCFS to achieve
this.
On land where farmers have accepted the
presence of hamsters, the ONCFS applies
the new protocol for protecting the hamsters. At Blaesheim the recent releases have
allowed a new wild population to emerge.
In the spring, as the breeding season
approaches, the ONCFS conducts a new
census of the burrows and tags animals
in order to find out more about their
biological cycle.
Males are released immediately, but any females
caught are sent to the CNRS in Strasbourg where
a vet implants a heat sensitive transmitter in
their abdomen to allow their movements to be
tracked. Once fitted with this device, the females
are released and the ONCFS staff conduct a radio
check twice a week.
The hamsters are
caught by placing
tasty morsels such
as carrots and
onions in a
“sexing box”.
The aim of this project, set up as part of the
2012-2016 National Action Plan, is to understand the demographic parameters of a wild
hamster population evolving in optimal conditions.
This study will also allow the researchers to establish the correlation between the permanent
ground cover vegetation and the number of
litters, in order to determine the causes for the
decline of the Black-bellied hamster and its hopes
for survival.
To find solutions which both protect
the species and agricultural production
is a challenge to which both ONCFS
and DREAL (the Regional Office for
Environment, Development and Housing) are working to find a solution.
The Black-bellied hamster of Alsace
has the potential to become, like the
white stork, an emblematic animal for
the region.
However, it still suffers from the
negative image of an animal which is
harmful to crops which prevailed in
the past. An image which may well be
difficult to change.
For more images please visit
www.naturepl.com
and search ‘Baccega hamster’
or contact
laurasutherland@naturepl.com