Handling of hybrids - the problem
In the course of domestication, dogs were formed according to the needs of humans, so that they differ in many characteristics from their wild ancestors. They become sexually mature earlier in life, but their behaviour remains "youthful" for a long time, i.e. they are educated by humans and subordinate themselves. We have taken the caution of the wolves from them - and cultivated many physical traits that distinguish them from their ancestral form. Many of these characteristics reduce the survivability of dogs in the wild. The intrusion of dog genes into the gene pool of a wolf population can therefore have adverse effects on them. The smaller the affected population, the stronger this adverse effect can be in rare crosses.
Because wolf-dog hybrids (thereafter called hybrids) are less well adapted to a life in the wild than wolves and also the wolf typical caution may be less pronounced with them, the probability that they come into conflict with humans more frequently is higher than with wolves. It is conceivable, for example, that hybrids are more likely to attack farm animals or that they are more likely to be seen near settlements than wolves. This does not have to be the case, but it is possible and causes fear in many people. However, there are no indications that wild hybrids are more dangerous to humans than wolves (L. Boitani, personel communication).
Legal status of hybrids
Hybrids in the first four generations are subject to the same protection status as wolves. This follows from Regulation (EC) No 1497/2003 amending Council Regulation (EC) No 338/97 on the protection of species of wild fauna and flora by regulating trade therein. It is stated in point 10 of the Explanatory Notes on the interpretation of the Annexes:
"Hybrids in which one or more specimens of a species from Appendices A or B occur in direct line in the previous four generations are covered by the Regulation as pure species, even if the hybrid species concerned is not explicitly listed in the Appendices".
The wolf is listed in Appendix A of the above-mentioned regulation and is therefore a strictly protected species according to § 7 para. 2 no. 14 BNatSchG. This means that hybrids are also subject to species protection.
Hybrids may therefore not be shot like dogs within the scope of hunting practice. Their removal from nature requires an exceptional permit under nature conservation law. This is expressly to be welcomed from a species protection point of view, as otherwise there would be the danger that wolves would be shot as supposed hybrids.
From the point of view of international species protection, hybridisations between wild animal species and their domesticated forms, in this case wolves and domestic dogs, are clearly undesirable and should be avoided under all circumstances. If hybridisations have already occurred, it is therefore necessary to take all necessary measures to prevent the further spread of domestic dog genes in the wolf population. Existing hybrids should be removed from the wild as soon as possible.
In the manifesto for the protection of wolves, published by the Wolf Specialist Group of the Species Survival Commission of the IUCN and in the LCIE Manifesto "Manifesto for large carnivore conservation in Europe", hybridisation between wolves and dogs is clearly rejected and considered harmful for the protection of the wolf species due to the possible negative effects. Recommendation No. 173 (2014) of the Bern Convention therefore calls on the signatories of the Bern Convention, including Germany, to ensure the state-controlled removal of proven wolf-dog hybrids from wild wolf populations.
Experiences in Germany
The development of the wolf population in Germany shows a clearly positive trend. Nevertheless, it cannot be ruled out that the population may be affected in individual cases by the occurrence of hybridisation with domestic dogs. Already in the year 2003 there was in Germany the first and until 2017 only proven case of a mating of a female wolf with a domestic dog near Neustadt/Spree in the northeast of Saxony. In autumn 2003 six puppies were found there, which differed phenotypically from wolves.
In January 2004 only four of the hybrid puppies were still alive. Within the framework of the Saxon Wolf Management it was possible to catch the wolf and one of the hybrids in a Lapp hunt. The female wolf was equipped with a radio trasmitter and released. The puppy, a male dog, came into an enclosure in the Bavarian Forest National Park. Two weeks later another puppy, a small female, could be caught with a foot loop. Also this animal was brought into the enclosure. The two remaining puppies disappeared suddenly and without a trace in February 2004.
The hybrids differed clearly from wolves in morphological and physiological characteristics as well as in behaviour. They were considerably smaller and lighter and had considerably shorter canines. The males became sexually mature already with eight months (wolves reach sexually maturity mostly only with approx. 22 months). The hybrid status of the animals was also confirmed genetically.
From the beginning, the captured hybrids showed signs of hospitalism and walked the same paths through the enclosure. When humans approached, they ran their circles and eights even faster. The enclosure was not accessible to visitors. The hybrids showed no signs of habituation towards the few people who cared for them, even after months. For the animals that had grown up in the wild and had been kept in an enclosure at the age of nine months, captivity obviously meant permanent stress. After less than a year, both animals were so badly injured through the fence by the wolves kept in the neighbouring enclosure that they had to be put to sleep.
In October 2017, another case of such a mating between a female wolf and a domestic dog became known. In the area of the Gotha-Ohrdruf training area in Thuringia, the territorial female wolf, which had been resident there since May 2014, had mated with a domestic dog in the spring of 2017 due to the lack of a wolf male and had given birth to hybrid puppies. However, this became known at the beginning of October 2017, when 6 hybrid puppies could be photographed on the training area. Since the animals were coloured black-grey and thus phenotypically very clearly different from European wolves, the hybrid status could be confirmed by the appearance alone. The genetic confirmation by the Senckenberg Research Institute, Gelnhausen, took place somewhat later, as there were no genetic samples of the puppies yet. Until the autumn, only samples of livestock cracks were available that could be genetically attributed to the mother and in which the puppies were not involved.
In such cases, the Thuringian Wolf Management Plan envisages taking hybrids from nature. Accordingly, the Thuringian Ministry for the Environment, Energy and Nature Conservation decided at the beginning of November 2017 that an attempt should be made to remove the animals from nature by the beginning of February 2018. A fast removal is important, because it is very possible that the hybrids already become sexually mature in the first year of life. Initially, intensive efforts were made to catch the animals alive. From January 2018, lethal collection was also promoted at the same time. At the end of March 2018, the TMUEN reported that three of the four hybrids still present in the area during the winter had been killed (two males, one female). The fourth hybrid, a male animal, was still in its mother's area until April 2019, when it was also killed. Further information on this case can be found at http://www.thueringen.de/th8/tmuen/index.aspx .