Wednesday, January 7, 2015

New map of #wolves' presence in Denmark

Researcher zone Natural History Museum, Aarhus and the Institute of Bioscience-Kalø, Aarhus University has just released the latest map of wolf occurrence in Denmark. The map shows the guarantee fund as well as documentation from the photos from game cameras.

PDF
 
The map shows that the wolves in Denmark have been documented in five areas: the most western part of Jutland, the area south of Herning Silkeborg, the area between Holstebro and Herning and in Thy. Furthermore, there is scattered evidence from Jutland. Visual observations of wolves are not included on the map, but wolves have been observed in many other places in Jutland.
 
It is now one and a half years since the first documented sighting of a wolf in Denmark. It began with  blurry photos of a wolf in areas of Thy, but later a wolf carcass was found lying not far from the photo spot. The animal was autopsied and by DNA testing, was identified as the first documented wolf in Denmark 199 years.
 
Since then there have been many observations and discoveries, which you can read more about below - or you can dive into the map above, as the Natural History Museum in Aarhus and the Institute of Bioscience-Kalø, Aarhus University has just released it; all evidence is documented sightings in Denmark.
Evidence is hard to prove
The aforementioned findings of the first documented wolf in Denmark in 199 years caused a surge of interest in the media and in the Danish population, and since then, the Natural History Museum, Aarhus and the Institute of Bioscience-Kalø, Aarhus University received, recorded and analyzed much information on sightings of suspected wolves. This research has been possible due to a major donation from the June 15 Foundation. This information spans everything from eyewitness reports from 2008 and from photos of individuals and paw tracks, as well as collections of suspected droppings and saliva samples from infected livestock and deer.
 
The information filed by individuals was assessed by people in ulvetracking.dk and the Nature Agency. It is often difficult to assess whether  a wolf or a dog is actually seen, and it is therefore important to document accurate information.
Many sightings have been found to be canine
In recent years, game cameras have been increasingly used by hunters inorder  to obtain information on wildlife in a given area. Such cameras have, in several cases, produced good images with a high probability that the subject was a wolf - sometimes even the sex was revealed. There are also new pictures from people who believe they have seen and even photographed a wolf. Some of these images show animals who are near roads or buildings, but almost all of these images have been shown to be of dogs.
Wolf paws are generally larger than dogs' paws
Because of the amount of snow in the early months of 2013, a lot of images of suspected wolf tracks were seen in the snow; however, in the winter of 2014, there has been a regrettable lack of snow and therefore fewer tracks. Paw Tracks of a wolf is very difficult to distinguish from paw tracks of dogs, unless you follow the tracks over long distances. Wolf paws are generally much larger than dogs, but there are large breed of dogs with equally large paws.
There is no additional information on the web (ulvetracking.dk), but there are photos of two parallel sets of tracks. It is also stated there that one animal urinated against a tree, while the second peed in the track - a possible indication of a male and female wolf.
Droppings can reveal floors deposits
In addition to tracking, wolf droppings have been collected. Although dog feces can be confused as belonging to a wolf, wolf droppings often have bone fragments and fur residues in them. Dog excrement is often quite structureless, except in the case of free-ranging dogs. Excrement also contains cells from the intestine and can therefore be sampled, which is used for DNA analysis.
The analysis can identify the species, and if the sample is fresh, also the individual can be discovered. Over time, one can determine how many wolves are out there.
 
This method requires continuous collections along with the creation of a DNA database that contains DNA profiles. The latter is just one aim of the project 'New species' supported by the 15 June Fund.
Fresh cadavers provide saliva samples
Since the first documented wolf occurrence in Denmark in 2012, the cry of  'wolf!' has been heard many times. The new map shows the instances of wolves in Denmark in the period up to now. (Photo: Shutterstock )
 
The wolves in Denmark are expected to mainly live on a diet of  red and fallow deer. Hikers will find the remains of these animals, and these cadavers can often be attributed to wolves; however, animal deaths can also be from a fatality, or from other predators. If carcasses are fresh, saliva samples from bite wounds or from bones can be collected and analyzed for DNA fragments. Shortly after the announcement of the first wolf, a flock of sheep was attacked and saliva samples from the sheep showed that both, dog and wolf, had eaten the sheep.
Details are difficult to document
Gradually, several Danes saw, what they believed, was a wolf. Such information is difficult to document and verify because the people involved are usually only see the animal briefly. This situation also fits with the wolves' reaction to people, as they flee at the sight or smell of us. In some cases, however, there are observations of longer duration, such as during a day or night in open areas.
There were two cases where ulvetracking.dk made sound recordings, which are believed to originate from wolves. These recordings have been analyzed by lydforskere which states that there could be several wolves in the same recording.
DNA profiles are compared with German register
All samples collected for DNA analysis have been analyzed at the Department of Bioscience-Kalø, Aarhus University. The analysis  determines whether the samples were from a wolf or a dog, as well as the identity of the individual. Dane DNA profiles have been compared with the DNA profiles in a German DNA database. Not all tests could be identify which wolf it was due to the nature of the test.
The new card: Wolves Status 2012-2014
From the above mentioned information gathering on the presence of the wolf in Denmark, subsequent documentation has been prepared along with a map showing either definite or almost certain instances of wolves from 2013 until the beginning of 2014. However, there are several samples from the same period of the analysis that will not be completed until the spring. From the map denotes wolf packs in Thy, the most western part of Jutland, the area south of Silkeborg-Herning, and the area between Herning and Holstebro.
 
Due to the different collection dates of the specimens, there is difficulty in assessing how many individuals are involved. Wolves can move over large distances in a short time. In each area there may also be several other species of animals.
 
Wolf incidences in Denmark are linked to the north German-Polish stock, and wolves that come from there, may also return. Evidence demonstrates that four different individuals reside in Denmark, all males, two of which came from Saxony; they were specifically, the Milkeler-couple, namely, the dead Thy-wolf and its half-brother that was taken in Gauteng. Two others came from western Poland from the Lubsko-group, near the German border. At the dawn of wolves' breeding season, it will be interesting to see whether this stock will be increased by wolf puppies in Denmark.

source