During the webinar, Alexander Sokolov gave a presentation and responded to questions.

Indigenous people have their own experience in wildlife observation. Do you use their knowledge and experience?

I believe and hope that the slides that I've presented show beyond all doubt that we do use their experience. Here is just one example. I failed to mention the fact that with support from the Yamal government we've received funding for tagging Arctic foxes. We plan to fit them with GPS collars, making it possible to track their movements via satellite, because this modern method is used by our colleagues in Canada, who have placed more than 200 GPS collars over the past 10 years. Since we received these collars, our team, which has extensive experience in the field, has failed to catch any Arctic foxes to fit them with these collars. And then I gave them to my friend, Takuchi Laptander, and literally two days later he called me back and said, watch your fox. He'd caught it! So I regard them as valuable partners who contribute no less than 50 percent to the success of our research.Every time we meet in  Erkuta, we collect data on phenological events: when ice breaks, when birds arrive and what kind of birds.

How many wild reindeer remain on the peninsula? What is the outlook for their preservation in connection with the industrial development of the northern part of the peninsula?

I belong to the category of researchers who will say honestly "I don't know" in response to most questions. I don't know because this is not my area of study. Such vast and remote territories require very serious resources. But of course, we can still say something. The most recent aerial count — if I'm not mistaken, in the 1980s — showed there were about 2,000 reindeer in the north of Yamal, Bely Island, the northernmost part of Gydan and Yevai Peninsula. I'm sure that industrial development does not affect this population in any way. Rather, it can be affected by the Nenets, who graze their herds of domesticated reindeer. However, generally, over centuries, the Nenets have seriously developed Yamal and, of course, in a manner of speaking, they take care of wild reindeer here on Yamal to make sure that they do not lead does away from their herds and they also hunt wild reindeer because their meat is more valuable. In other words, there are no up-to-date figures but I believe that — when I worked on Bely last year, we saw those reindeer every day, but how many are there? This calls for a special study. I think that their numbers are more or less the same. And of course there must be some kind of exchange with wild reindeer from Taimyr, which, as far as I know, has the largest herd in the world. As for the number of domesticated reindeer on Yamal, prior to the 2014 disaster, it was put at 700,000 (or 650,000); at present, there are about half a million, 550,000. So these are 100,000 of death loss. There are very significant numbers of domestic reindeer. This simply leaves no room for wild reindeer. The whole of Yamal, as far as its northernmost point, is covered by grazing herds.

Do you collaborate with other researchers from Russia who study rodents in the Arctic? In what parts of our country do they work?

In 2008, the Yamal government sponsored a meeting as part of our project. At the time, we tried to find researchers who had worked in the northern Arctic in the golden years of the Soviet science, in the 1970s-1980s. We scoured the Russian Arctic for people who could come to us and talk about their results. Gennady Katayev from the Lapland nature reserve and two people from Taymyr came, but unfortunately, that was it.

I know that the Institute of Biological Studies of the North is actively working. In the past, there were such northern researchers as Chernyavsky, Dorogoi and Tkachyov. The Yelshins used to work in the Nenetsky area. There are a lot of names. But unfortunately, for some reason we've lost touch over the vast expanse of the Russian Arctic. Generally, there are only a handful of rodent researchers left today.

How do you assess the domestic reindeer's impact on the tundra ecosystem? After all, it's an open secret that Yamal is heavily overgrazed.

Indeed, in some areas, there is significant overgrazing, for example, near the villages Novy Port and Mys Kamenny, and on the coast of the Gulf of Ob. But then we hosted Virve Ravolainen, who works in northern Norway, area that is also exposed to significant overgrazing. And when we arrived at the Erkuta, she said we needed more deer. She was stunned to see so much vegetation: Compared to northern Norway, it was almost all intact.

And there's another important point. I'd like to draw your attention to the fact that it is not quite correct to consider overgrazing only in the reindeer-vegetation context. In my slides, I've shown the results of our two-year experiment. They show that reindeer are certainly not the only consumers of plants. An ecosystem approach means measuring the impact of other actors: rodents, hares, ptarmigans, etc., in different parts of the Arctic, including Yamal. Measurements are essential here. I know that so far this area of study is rather limited, but elsewhere — in the Canadian Arctic, Greenland — it has been shown experimentally, for example, that rodents consume far more green mass than caribous do. But again, to reiterate, it is very important to synchronize our studies to understand what is happening in different parts of the Arctic.

You said that birds of prey mostly feed on lemmings, whose numbers today are falling. Do your observations suggest whether these birds can switch to [dead] seals left by indigenous people, thus replacing one food source with another?

This is an oversimplification. It depends on the species, say, the snowy owl or the buzzard. In all likelihood, in some regions, buzzards can switch to alternative sources, for example, the ptarmigans. Other than the white-tailed eagle, I don't think other birds of pray, such as the snowy owl, the gyrfalcon, the peregrine falcon or the rough-legged buzzard feed on carrion. The white-tailed eagle is a another case. Its numbers are visibly growing and it is moving further to the north of Yamal. Last year, Sofya Rozenfeld, our colleague from Moscow who is involved in aerial studies of geese populations on Yamal, repeatedly reported instances of white-tailed eagles hunting geese, including the lesser white-fronted goose, an endangered species. Again, this brings us back to the ecosystem approach and the importance of studying the maximum possible number of elements in the ecosystem.