an endangered species
By: Louise Adolfsson &
Anniko Nydal
2:nd year 2003
Wildlife elective course
Szent Istvan University
Budapest
TheScandinavian Wolf – an endangered species
1 . Introduction
In this essay, we aim to give a brief description of the problem with wolves in the wild in Scandinavia, with a focus on our home country Sweden. Here there are constantly major conflicts between human interests in the wild game, the native Samee population - who yearly loose hundreds of their reindeers taken by the wolves - and activists working for a protection of the wolf species. Last summer Louise had a practice with wildlife veterinarian Bengt Röken at Kolmården Zoo in Sweden and thereby got some practical knowledge of the breeding work done by some European zoos. Unfortunately inbreeding is a common problem even in the zoos, since the breeding populations are of very small numbers.
2 . The wolf – Canis lupus
SPECIES DATA
Order: Predators, Carnivora
Family: Canidae
Habitate: Forest
Social organisation: Family
Height: 60-70 cm
Weight: sire 40-50 kg, bitch 25-40 kg
Diet: Meat
Sexual maturity: 22 months
Gestation period: 63 days
Number of offspring’s: 1-6
Age: 10-15 years
CITES: II
Present number of individuals: 18
Present number of breeding units: 0
3 . History
The relation between man and wolf has always been impressed by ambivalence. We took it to us 5000 years ago and have ever since that domesticated it to the dog, which is said to be the best friend of the man. Simultaneously, we continued being concurrents with the wolf about the hunted quarry and later it also became a threat against our cattle and pets. It is probably this old conflict that is the background of the hate that many people feel against the wolf. In previous times when the whole economy of a family could depend on one single cow, it was the same as a catastrophe if a wolf killed it. That’s why it was a law that everyone who cough site of a wolf had to kill it in the purpose of totally extinction it. Today we are not that threatened though, since we have larger farms, we can get compensation from the state for killed animals and there are effective methods for protecting the animals from predators. The reputation that the wolf is a dangerous animal for the human as well, is an unfair accuse. The wolf is namely a very shy animal that, if possible, stays away from people. There are no documented cases from a wolf killing or even hurting a human in Sweden (Amundin, 2002).
4 . The wolf in the wild
In the wild, a flock of wolves normally consists of a dozen animals, with one parental couple, the so-called alpfa-coulpe, and their offspring’s in different ages. The flock is held together by the strong bands between the parents. When one of them dies, the flock is separated and the strongest individual becomes established as the new alpha-wolf. Hopefully it can attract a new partner, which is not a relative of the flock, with a little help from its widespread howling. Another option is that a new couple comes and takes over the whole flock. The alpha-bitch only has one sexual cycle a year, and her estrus is in February-March. At this time she becomes very aggressive and prevents the ovulation of her young daughter by her dominant manners. In the same way, the alpha-male prevents his sons from mating their own mother or sisters. In this natural behaviour inbreeding is prevented. In the cold winters the wolves are gathered in larger flocks with more than one alpha-couple. This is due to the fact that only larger quarry like moose’s, are to be found in the forests, and that these are harder to catch and more power is needed to kill the large animals. The large prey simultaneously gives more food so no one will have to starve. In springtime, the flock is splitted again since more and smaller animals are to be found which separate individuals can kill. Some youngsters normally stay with the parents to help them with the puppies, which are borne in the end of May. The 4-7 puppies are blind and death at birth, and they stay in the lair until 3-4 weeks of age when they also start eating meet, pre-chewed by their siblings or parents. In the socialisation process, the domesticated dogs are accepting the human as their leader, and here is a large difference in the wild dogs. In the zoological parks, one can see the relatedness between dog/wolf in the way the wolf are accepting the human leader that takes care of it from a low age (Amundin, 2002).
5 . Breeding goals in captive and wild wolf populations
There are two primary genetic effects of small population size; inbreeding increases and genetic variability is lost through the process of genetic drift. Genetic drift refers to the random change of allele frequencies caused by a restricted population size. Small populations may result in loss of allelic diversity, since alleles present in a parent generation will, by chance, not be transmitted to the progeny. Both these effects are regarded as threats to the long-and short-term survival of a population. They reduce the evolutionary potential for future adaptations and may result in inbreeding depressions that in turn may affect population survival by reducing the fitness (Laikre, 1996).
The wolf conservation project in Scandinavian zoos aims at preserving the genetic characteristics of the Fennoscandic wolf. The goal with the breeding project is to get offspring’s with the lowest inbreeding-coefficient possible and this can only be reached if new founders are used. There is also a second idea in the breeding programmes and this is to later use the park-models as a model for the wild populations.
In these wild populations breeding goals are documented in different governmental conventions, EU-directives and also in the Swedish law. In the convention on biological variety from 1993, three goals are set: to beware the biological variety, to secure a stable usage of the variety and to cause a justice distribution of this usage. This also includes an expected respect for human minority cultures, which in Sweden means the Samees in the northern parts of the country, who experience negative effects of large populations of wolves. The species- and habitat directive of EU, list species in need of particular protection, and the main rule here is that it is forbidden to purposely capture and kill listed animals. In the CITES-ordinance, the trade of endangered species is regulated and special conditions are required for import and export of these animals.
Today the wild population of the Norwegian /Swedish populations are as small as only around 100 individuals. It is thus of great importance that it quickly grows to 200 individuals to decrease the risk of inbreeding. This level is a part of the goals in a short-termed preservation and before the population has reached this level, hunting must be very limited. It should also be easier for the Finnish individuals to migrate south through the country. A long-termed goal is to get the Swedish population to a level of 500 animals.
(www.wwf.se)
6 . Breeding of captive wolves
The Scandinavian captive wolf population descends from four founders of Fennoscandic origin. These were two wild-caught, full-sib pairs captured in Sweden and Finland in the early 1950s and 1960s, respectively. Since the wild wolves producing these animals were presumed to be unrelated, this implies that there were four initial founders if Fennoscandic origin. In addition to these founders, two Russian animals have contributed genes to the population; two female litter mates were imported from a zoo in Russia in 1980. The Russian animals were introduced into the program to reduce inbreeding, but little or no attention was paid to the effects of this step on the basic goal of preserving the Fennoscandic genes. The introduction has resulted in the spread of genes of non-Fennoscandic origin, but as yet the probability of survival if Fennoscandic alleles in the animals is not affected by the introgression of Russian alleles, since the Fennoscandic parents of all “hybrids” are still alive (Laikre, 1996).
The wolves in the zoological parks have been a subject for inbreeding, since there is often only one flock which only have their own relatives to mate. In the 90s, eye-problems like blindness and other, from the breeding of dogs, common problems were found among the captured wolf populations (Amundin, 2002). Analysis has been made comparing the negative effects of inbreeding in four qualitative characters; reproductivity, longevity, juvenile weight and blindness. It is found that inbreeding negatively effects all these characters. Weight reduction is correlated to a larger extent with inbreeding of Swedish founders, inbreeding of Finnish genes appears to be more directly associated with longevity and reduced reproductivity, and it is also only the Finnish inbred animals that are affected by blindness. The Russian descendants appear to reproduce better than those with a pure Fennoscandic background.
To improve the populations, Kolmården have a co-ordinator for the breeding of wolves, and he is now leading the decontamination work in all the parks in Sweden that are breeding wolves. He is using a computerised programme called SPARKS (Single Population Analysis and Record Keeping System) for counting how many and which wolves that theoretically should mate and how the non-related wolves, imported from Russia and Estonia, best should be used. A breeding exchange also exists between zoological parks in the Nordic countries. The participating parks are; Norway: Kristiansand, Polarzoo and EKT, Finland: Ranua and Aktri and finally Skåne Djurpark, Nordens Ark, Borås Djurpark, Kolmårdens Djurpark, Skansen, Järvzoo, Orsa Björnpark and Lyxele Djurpark in Sweden.
At the moment Kolmården has no alpha couple, the last one consisting of Navdi and Varis moved together with all their offspring’s to Berlin Zoo in December 2001. A new couple is expected to come in 2004 and the major goal of the co-ordinator is to get a new alpha couple from Finland (Amundin, breeding co-ordinator, personal communication). Once a breeding pair is successfully established, it is usually kept for many years and others are thereby prevented from reproducing. This result undoubtedly in loss of genetic variability and a more frequent exchange of founders would be optimal in helping solving this problem. But since the wolf is practically extinct in Sweden, it is not possible to bring in new founders from the wild and this problem is thereby difficult to solve.
Unfortunately, the breeding programs exemplifies in many ways the negative effects of lack of genetic planning. From a standpoint of achieving a regular reproduction and a steady increase of the population size, it is quite successful, but from conservation genetics perspective it has not been a success. The programmes are characterised by severe loss of founder alleles and remarkably high levels of inbreeding and inbreeding depressions. In order to achieve healthy wolf populations we might have to let loose the goal of preserving the genetic characteristics of the Fennoscandic wolf and instead introduce more of the healthier Russian animals. There are no data on the degree of genetic similarities between these breeds, but in absence of appropriate founders, new programmes must be designed for the present population with the following aims. The rate of which alleles are lost has to slow down and the frequency of the alleles causing blindness has to be reduced. Animals that are likely to carry genes causing blindness have to be identified since these animals are not suitable for breeding programmes. One difficulty here is that the animals are not born blind and therefor may learn to find their way in the enclosures. Therefor, the defect might be difficult to detect without conducting a closer examination.
· Amundin Birgitta and Mats ………………Våra Djur, 2002
· Blomqvist, MacKeown……………………..EEP Felid Regional Collection Plans and Veterinary Guidelines
· Laikre Linda………………………………..Genetic Process in Small Populations, 1996
Personal communication
Amundin Mats………..breeding coordinator, Kolmårdens Djurpark
Röken Bengt Ole……...veterinarian, Kolmårdens Djurpark