Norwegian authorities on Thursday reported more than a dozen unexplained reindeer deaths in the Svalbard archipelago in the Arctic, considered "highly unusual" for the summer season. During an annual count, 13 recently deceased reindeer -- 11 females and two males -- have so far been found in two Svalbard valleys located a little over a 1,000 kilometers (620 miles) from the North Pole, the local governor's office announced. "It is very unusual for females of breeding age and adult males to die during the summer. That's why we want to monitor this development closely," it said. The causes of death are not yet known, and authorities have called on the public to report any new carcass finds. The Norwegian Institute for Nature Research (NINA) told AFP it had "no clear indication nor any specific hypothesis" to explain the unusual summer deaths. "In winter, it is mainly the youngest and oldest individuals that die," said researcher Vebjorn Veiberg. "The animals found dead this summer are, on the contrary, in the most vigorous and productive period of their lives," he added. "Veterinary specialists are naturally looking for an explanation related to disease. However, it seems unlikely that a disease would primarily affect the most robust animals." Svalbard, roughly twice the size of Belgium, has a population of around 22,000 reindeer -- about seven times more than the number of people. They are significantly smaller in size than the mainland reindeer.
