The European mink is critically endangered throughout its range. Several reintroduction programmes are in place to help assure the survival of the species. One of these is currently underway in Estonia, where researchers from the Vetmeduni Vienna closely studied the reproductive cycle of female animals. Analysing hormones in faecal samples, the scientists confirmed for the first time that females are able to conceive three to four times a year. The results, published in the journal Theriogenology, should assist efforts to reintroduce the animals in the wild.
The European mink (Mustela lutreola) is one of the most endangered mammals in Europe. The reasons for its decline are the destruction of its habitat in riparian areas, competition with the alien American mink and historically, extensive hunting.
The European mink is often confused with the American mink (Neovison vison, previously Mustela vison), which has successfully established itself in Europe as an escapee from fur farms. The larger and more robust American mink has nearly completely replaced the European mink in its previous range.
Species protection projects all over Europe have so far faced the problem that European minks are difficult to breed in zoos. Captivity appears to have a negative effect on breeding success. But captive-bred individuals are needed in order to release and reintroduce the animal into protective zones. “The more we know about the physiology of European minks, the better we can respond to their needs,” says lead author Franz Schwarzenberger from the Institute of Physiology, Pathophysiology and Experimental Endocrinology at the University of Veterinary Medicine, Vienna.
Faecal samples yield reproductive data
Scientists from the Vetmeduni Vienna, in cooperation with the Endangered Species Research Lab of Tallinn Zoo, collected faecal samples from European mink and analysed them in Vienna. The animals are managed under the aegis of an EEP program (European Endangered Species Program). Female oestrus is usually determined by vaginal cytology. The aim of the study was to assess the validity of this method and to optimise diagnosis of ovulation and pregnancy.
“Using our non-invasive method, we were able to measure female oestrogen levels and generate a seasonal hormone profile. The results showed that oestrogen levels are higher at the time of ovulation. Such oestrogen peaks occur three to four times a year on average. The animals are polyoestrous. That means, during the breeding season they are fertile in regular intervals. In the past, females which had already been mated with no success were not mated again that same year. Our results reveal that mating can occur much more often,” Schwarzenberger explains.
Looking for the perfect mate
European minks are solitary animals and extremely territorial in the wild, only approaching each other during the breeding season. In captivity, the animals are housed in large individual enclosures. “The exact time for mating is difficult to determine in a zoo because the animals attack each other if they aren’t receptive. In order to increase the chances of fertilisation, the females are examined at regular intervals during the mating season. During mating, we also closely observe the behaviour of the animals, especially of the males,” explains Astrid Nagl, first author of the study.
The Tallinn Zoo uses vaginal cytology to predict the time of ovulation. This method does not always yield satisfactory results, however. “The data from the faecal analysis serve to augment the available information so that some females which had previously not been mated successfully also had offspring,” Schwarzenberger reports.
Reintroduction in Europe not possible everywhere
The reintroduction of the European mink in Austria would not be easy. “In Austria, the American mink has replaced the European mink in aquatic and riparian zones,” says Schwarzenberger. Releasing the European mink in this habitat would be tantamount to a death sentence, as the American minks would defend their territory and kill the European Mink. This makes reintroduction only possible in areas where no populations of American mink exist,” says Schwarzenberger.
About 100–120 European mink live at Tallinn Zoo. The zoo’s captive-bred animals are reintroduced to the wild on the Estonian islands of Hiiumaa and Saaremaa. Another promising reintroduction project can be found at Steinhuder Meer in northwest Germany.
The article “Non‐invasive monitoring of female reproductive hormone metabolites in the endangered European mink (Mustela lutreola)”, by Astrid Nagl, Nadja Kneidinger, Kairi Kiik, Heli Lindeberg, Tiit Maran and Franz Schwarzenberger was published in the journal Theriogenology. http://www.sciencedirect.com/science/article/pii/S0093691X15003817
About the University of Veterinary Medicine, Vienna
The University of Veterinary Medicine, Vienna in Austria is one of the leading academic and research institutions in the field of Veterinary Sciences in Europe. About 1,300 employees and 2,300 students work on the campus in the north of Vienna which also houses five university clinics and various research sites. Outside of Vienna the university operates Teaching and Research Farms. http://www.vetmeduni.ac.at
Prof. Franz Schwarzenberger
Institute of Physiology, Pathophysiology and Experimental Endocrinology University of Veterinary Medicine Vienna (Vetmeduni Vienna)
T +43 1 25077-4104
Scientific Contact (Tallinn Zoo):
Tiit Maran, Ph.D.
Species Conservation Lab, Tallinn Zoo
phone +372 6943318
GSM +372 5066859
University of Veterinary Medicine Vienna (Vetmeduni Vienna)
T +43 1 25077-1151
Heike Hochhauser | idw - Informationsdienst Wissenschaft
New photocatalyst speeds up the conversion of carbon dioxide into chemical resources
29.05.2017 | DGIST (Daegu Gyeongbuk Institute of Science and Technology)
Copper hydroxide nanoparticles provide protection against toxic oxygen radicals in cigarette smoke
29.05.2017 | Johannes Gutenberg-Universität Mainz
The world's highest gain high power laser amplifier - by many orders of magnitude - has been developed in research led at the University of Strathclyde.
The researchers demonstrated the feasibility of using plasma to amplify short laser pulses of picojoule-level energy up to 100 millijoules, which is a 'gain'...
Staphylococcus aureus is a feared pathogen (MRSA, multi-resistant S. aureus) due to frequent resistances against many antibiotics, especially in hospital infections. Researchers at the Paul-Ehrlich-Institut have identified immunological processes that prevent a successful immune response directed against the pathogenic agent. The delivery of bacterial proteins with RNA adjuvant or messenger RNA (mRNA) into immune cells allows the re-direction of the immune response towards an active defense against S. aureus. This could be of significant importance for the development of an effective vaccine. PLOS Pathogens has published these research results online on 25 May 2017.
Staphylococcus aureus (S. aureus) is a bacterium that colonizes by far more than half of the skin and the mucosa of adults, usually without causing infections....
Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.
The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....
An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.
We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...
Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.
Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...
24.05.2017 | Event News
23.05.2017 | Event News
22.05.2017 | Event News
29.05.2017 | Earth Sciences
29.05.2017 | Life Sciences
29.05.2017 | Physics and Astronomy