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A Real Success Story – How the Hungarian Meadow Viper Was Saved from Extinction

Hungarian meadow viper in Szeged Zoo (photo: elajos)While some conservationists oppose or at least debate the raison d'être of ex situ conservation, there are positive examples which show the effectiveness of cooperation with in situ methods. The great success of the Hungarian Meadow Viper LIFE-project is a good example for this. In addition, this conservation project works well with zoos, which makes it a good example of this kind of cooperation.

When the project started in 2004, there were only about 500 Hungarian meadow vipers (Vipera ursinii rakosiensis) in the wild, and the species was considered almost extinct. Their number - including the captive population - has quadrupled since then, thanks to the ex situ breeding, habitat reconstruction and repatriation. The European Union supported this program as a LIFE+ project. Many zoos in the region also support it with educational and awareness campaigns (Hungarian Meadow Viper Day), Budapest Zoo provides veterinarian help and visitors can meet these vipers in some zoos (actually in Budapest, in Vienna and in Szeged).

 Hungarian meadow viper in Szeged Zoo (photo: elajos)The Hungarian meadow viper
This subspecies of the widely distributed meadow vipers or Orsini’s vipers (Vipera ursinii) used to live in the lowlands of the Carpathian basin in great numbers until the early 20th century. But as a consequence of cultivating the steppes, eliminating floodplains and increasing regular disturbances, the natural habitats of this viper subspecies decreased rapidly. In addition, the fear of snakes also led to the death of many vipers. There is only one  slightly - dangerous venomous snake species in Central Europe, the common adder (Vipera berus), which is slightly similar in appearance to the meadow viper. Therefore, people usually used to kill meadow vipers – and other harmless – snakes, although all reptiles are protected in Hungary. Hungarian meadow vipers today only live in two areas of the country (Hanság and Kiskunság), and recently several populations were found in Romania (Transylvania).

Hungarian meadow viper males (source: rakosivipera.hu)The Hungarian meadow viper was discovered in 1893. Lajos Méhely described it first as a subspecies of Vipera berus, but later the snake was identified as a subspecies of Vipera ursinii. The taxonomy of several forms of meadow vipers is a subject of debate. The species lives in a huge area, from Southeastern France to western China, but because of habitat destruction its numbers are decreasing. Therefore, this species is considered as Vulnerable by the IUCN Red List of Threatened Species. Some subspecies  live in mountainous regions  others inhabit lowland steppes, eg. in Hungary. The recent genetic and biochemical researches support the idea of defining the Hungarian populations as a distinguished subspecies.

Birth of vipers (source: rakosivipera.hu)The Hungarian meadow viper is a small, 50-60 cm (19.7-23.6”) long snake, with females being larger than males. It feeds mainly on insects, especially crickets, locusts and grasshoppers. This may be the reason of it having weak venom which is harmless to humans – in most cases (except the allergic reactions). The snake prefers grass habitats that have both dry and wet areas. Meadow vipers are ovoviviparous, they have 4-16 eggs which develop inside the mother’s body.

There is an interesting story about changing the Hungarian name of these vipers for political reasons. Its Hungarian name, ‘Rákosi vipera’ was changed in the 1950s because Mátyás Rákosi, the arrant communist leader of Hungary at the time ordered scientists to rename the snake. After the fall of the socialist regime, the viper got its name back in the early 1990s.

Facilities in the conservation centre (source: rakosivipera.hu)The conservation of the Hungarian meadow viper
The protection of Hungarian meadow vipers started in 1974, before the species was put under strict protection in 1988 and finally, in 1992, its status was raised to the highest conservation category. However, despite the enhanced protection and conservation activities, the number of these snakes has decreased to about 500 specimens. The situation changed in 2004, when the Hungarian Meadow Viper Conservation and Exhibition Centre was established in the area of Kiskunság National Park. The Centre is operated by MME BirdLife Hungary in the frame of the LIFE and LIFE+ projects (supported by the European Union). The main goals of the conservation project were collecting vipers from different habitats to start breeding in seminatural outdoor enclosures in the Centre, researching these snakes, habitat reconstruction, which made some areas suitable for releasing the offsprings, and – last but not least – educating the public.

Young vipers are coming out from the wintering pipe (source: rakosivipera.hu)Why did we need ex situ conservation instead of solely relying on the protection of wild populations? In the highly fragmented and disturbed habitats the natural population growth of these vipers was insufficient due to the very few number of adults in these areas and the large chance of inbreeding. Without “strengthening” the population with ex situ breeding, the fate of the wild population would have been certain extinction. In the Conservation Centre the breeding of the vipers is based on a clear genetic background, and the survival rate of young snakes is much larger than in the wild.

As project leader of LIFE Plus Bálint Halpern said, the Centre started with 10 animals that were captured in 4 different habitats in 2004, and 6 more snakes arrived in 2007-2008. The diagram below shows the great success of the breeding: until 2014, more than 2000 vipers were born in the centre! The average litter size was around 10, the most fertile female gave birth to 27 babies.

The vipers spend the winter in special artificial holes in their outdoor enclosure. These holes are terracotta pipes which are about 1 meter in length, have variable-width, and are dug into the ground at an angle. The vipers are moved to the releasing site in these pipes when they are repatriated.

However, before releasing, the main task is to make their habitat suitable for them. In the frame of the LIFE+ project, the habitat reconstruction has started in several territories of Hanság and Kiskunság. Three agricultural fields have been reduced in the area, the cleaned territories were seeded with grass, and the fragmented populations were connected with ecological corridors.

Annual number of viper born in the HMVCC (source: see in the reference)There is another equally important goal besides breeding and releasing the vipers: raising public awareness. It is important to win the support of the public, and to reduce the aversion to vipers. The educational programs help accept and make people understand the important role of vipers in the ecosystem. The Conservation Centre is open for visitors all year round as an exhibition. The nature trail which was created to show the natural habitat of these snakes - and the Centre can be visited with professional guide only, after booking.

Zoos and the Hungarian meadow viper conservation project
As the experts of ex situ keeping and education, the zoos of the region also support the project. Budapest Zoo provides veterinary support, Dr. Endre Sós, the leading vet of the zoo presented this work at the EAZA Annual Conference in Budapest (2014).

Blood sampling from V. renardi (source: see the references)The veterinary background is very important in any breeding and reintroduction project. Dr. Endre Sós emphasized the importance of a comprehensive approach. How does this work in this project? As he said, it includes screening the wild animals arriving to the centre and the animals of the captive breeding program, disease treatment and reproduction follow-up in the centre, studying the wild populations and post mortem examinations. It was important to choose a model species to develop and test the materials and methods.

The steppe viper (Vipera renardi) was chosen as a species to gain experience and information, before starting to use risky techniques on Hungarian meadow vipers. In addition, the expert team started to collect Anaesthesia (source: see the references)bacteriological, parasitological and virological samples from the Hungarian meadow vipers in the centre and also from the incoming specimens. To reduce the risk of snake bites and to make examinations possible (e.g. X-ray, ultrasound), developing the safest anaesthetic method was very important. The vets used ketamine for premedication (40-80 mg/kg) and isoflurane for maintenance of aneasthesia.

The observed diseases were the following: shedding problems (causes: low temperature/humidity, poor conditions, poor husbandry – a warm bath could help), genetic problems, parasites (mites under the scales) and trauma.

Intracoelemic surgery: Implantation of a radiotelemetry tansmitter (source: see the references)For the follow-up of the released snakes it was necessary to develop a method of radiotelemetry. The technique (the VHF transmitter and the temperature logger) was developed in Austria (Research Institute of Wildlife Ecology, Vienna). New species were chosen to practice the surgery and to observe the possible complications: the corn snake (Elaphe guttata) and the Milos viper (Macrovipera schweizeri). The photos below show the implantation of the transmitter. The developed technique showed promising results, the surgery proved to be quick and safe, the animal acted normal. As you can see in the map, the routes of the released specimens were successfully followed. The one marked with yellow disappeared shortly after being released from a higher point – as Bálint Halpern told me, it probably was preyed on by a marsh harrier (Circus aeruginosus). 

Releasing Hungarian meadow vipers (source: see the references)
Hungarian Meadow Viper Day in Szeged Zoo (photo: elajos)Naturally, zoos have another important task in the conservation of Hungarian meadow vipers: education. Many Hungarian zoos take part in the Hungarian Meadow Viper Day, on the first Saturday of September, which helps to reach out to more people. Visitors can see live snakes at Budapest Zoo and more recently at Szeged Zoo, too. The snakes live in a terrarium in the “House of Venom” in Budapest, in Szeged the vipers can be found in one of the outdoor exhibits of native reptiles. The second zoo to start keeping Hungarian meadow vipers in a permanent exhibition was Schönbrunn Zoo, as the main attraction of the “Biodiversity Week”. All three zoos consider this viper as an important flagship species, and their education work is focused on these animals among others.

Terrarium in Budapest Zoo (source: rakosivipera.hu)How to keep Hungarian meadow vipers
The vipers are kept in a traditional terrarium at Budapest Zoo, but at the zoos in Vienna and Szeged they live in outdoor exhibits. These animals naturally live in a temperate climate, therefore outdoor terrariums are a good solution for keeping them, as the snakes can spend the winter in their enclosures.

Hungarian meadow vipers prefer grasslands, where the wet and dry areas create a mosaic. It is suggested to plant Festuca sp. in the short grass, thus providing hiding places. As other snakes, these vipers like to warm themselves in the sun, too. You should provide basking areas, and – especially in the case of outdoor terrariums - warm places (heat rock, heat cable in Hungarian meadow viper exhibit in Schönbrunn Zoo (Vienna) (source: rakosivipera.hu)concrete). In the case of outdoor exhibits, the wall does not need to be higher than 60 cm (23.6”), because being terrestrial snakes they cannot climb smooth walls, though it is advised to add an inner edge to the top of the wall for safety. The ground surface or grass carpet should be closed and without gaps to prevent the vipers from hiding in unexpected places. The vipers should be protected against their predators (for example storks, birds of prey, foxes), so it should be covered.

The surface of the ground should have some elevations and depressions. In case of outdoor terrariums it is necessary to make holes in the underground barrier (usually plastic) layer to prevent flooding in case of heavy rains. The diameter of these holes should be less than 5 mm (0.2”), which is small enough to prevent sliding through.

The wintering pipe (source: see the references)The opening of the wintering tube should be slightly above ground level, this will also protect the snakes from flooding. It is also suggested to shelter the opening against rainfall. These snakes are terrestrial, they don’t need large climbing facilities and huge stones. However, providing a heated place for them using an electric heater is good for both the snakes and the visitors, who will have a better chance to see them. These vipers are small and prefer hiding in the grass, therefore it is difficult to notice them. This is why open warming and sunbathing spots could improve the exhibition in the eyes of visitors.

Naturally, Hungarian meadow vipers are also kept in traditional terrariums. At Budapest Zoo the area of the enclosure is about 1 m2 and the temperature is between 24-28°C (75.2-82.4 F). The vipers are active throughout the year, without hibernation. Especially in these smaller places we should be cautious during feeding, since the vipers might bite each other.

Enter the wintering pipe (photo: elajos)They are mainly fed live crickets or  – after removing the large hind legs,as these could hurt the vipers - locusts. They can sometimes be fed baby mice, too. The vipers start to hunt after the insects are released in the enclosure. Naturally, as the average temperature drops in autumn, their appetite also decreases before they hide into their wintering tube.

As these snakes are viviparous, breeders do not have to care about their eggs. The vipers start to breed around the age of 3-4 years, their mating season is in April-May. The babies are born between late July and early September. The newborn vipers’ weight is 2.4 grams and they are about 138 mm (5.4”) in length.

Hungarian meadow vipers are venomous snakes, but usually their venom is not strong enough to cause serious problems in humans. Although they are not aggressive snakes, they often bite when they are caught. This species secretes haemotoxic venom that causes haemolysis, haemorrhage, and mild tissue damage also occurs – as with many other viper venom, but to much less extent. Usually calcium tablets or injection is enough to treat the bite, but it is suggested to use antihistamine against allergic reactions when they occur.

Endre Sós, Chris Walzer, Tamás Péchy, Tamás Tóth, Zoltán Lajos, János Gál, Péter Kertész, Viki Koroknai & Bálint Halpern: The Hungarian Meadow Viper program - an update - presentation in the EAZA Conference (Budapest, 2014) – link (It was one of the source of the diagram and many photos)
Bálint Halpern: Introduction to Hungarian Herpetofauna – reptiles and their conservation - presentation in the EAZA Conference (Budapest, 2014) – link
Official webpage of the Hungarian meadow viper Life-project - www.rakosivipera.hu
Webpage of The Amphibian and Reptile Conservation Group of MME BirdLife - www.khvsz.mme.hu

Zoos keeping Hungarian meadow vipers (in 2014):
Budapest Zoo (Hungary) - www.zoobudapest.com
Schönnbrunn Zoo (Vienna, Austria) - www.zoovienna.at
Szeged Zoo (Hungary) - www.zooszeged.hu

Examining the wintering viperas (photo: elajos)Viperas in the wintering tube (photo: elajos)


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#1 L_E_dr 2014-12-03 18:39
This is a very valuable and interesting review.

Useful original photos and videos can be seen in Tibor Sos (Transylvanian herpetologist)' s website: http://www.tiborsos.webs.com . I suggest to view them.

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