Dataset 716
Waterfowl counts in Pasvik nature reserve, 1996-2020
Realm: Freshwater
Climate: Polar
Biome: Large river ecosystems Central latitude: 69.150000
Central longitude: 29.250000
Duration: 25 years, from 1996 to 2020
Climate: Polar
Biome: Large river ecosystems Central latitude: 69.150000
Central longitude: 29.250000
Duration: 25 years, from 1996 to 2020
794 records
54 distinct species
Across the time series Aythya fuligula is the most frequently occurring speciesMethods
The annual waterfowl registrations in Pasvik nature reserve have largely been carried out in the same way from year to year. The survey area has been the river stretch from Hestefoss to Jordanfoss, inclusive Cuckoo Bay, Fjærvannet and the bays on the Russian side. The area has been divided into nine counting zones; five to Norwegian side (Zone 1, 2, 2A, 3 and 4) and four on the Russian side (Zone 1, 2, 3 and 4) (see map in Figure 1). The counts have been carried out from small river boats, one on the Russian side and one on the Norwegian side of the river. In eachboat, there must be a boat driver and at least one observer with professional competence. All waterfowl that remain seen or heard, on or in connection with the river, is recorded. In most years, the spring censuses have been carried out by Norwegian and Russian researchers in collaboration, but in some years Norwegian researchers alone have had to be responsible the counts on both sides of the river. Before the counts start, the researchers meet in Bjelkestua at Varlamasaari for planning the work and socializing. This is an important part of networking between researchers on both sides of the border. Censuses were carried out in the river section between Hestefoss and Jordanfoss, includen the Norwegian and Russian sides. Birds were counted from small boats, one on the Norwegian side and another one on the Russian side. Each one had at least one pilot and one experienced observer. They recorded all the birds seen or heard on the river or the surroundings, moving from south to north. In the way back south, they only recorded new species. At specific points, other observers completed the censuses from the shore. Every year, 2 coordinated censuses took place in late May - early June. In 1998 and 2003, the second spring census was carried out only on the Norwegian side. In 2018, there was only one spring census. The maximum number recorded in the two censuses for every species was reported. Autumn censuses were included later and sometimes were only carried out on the Norwegian side. All the counts take place primarily down the river from south to north. As far as possible, the two boats runin parallel to avoid double counting of flying birds. On the Norwegian side, people have usually chosen to go ashore on the headland in the middle of Gjøkbukta to count from land with a telescope. This is to avoid mass transfer and ensuing chaos. The same method has occasionally been used at Noatun and also elsewhere if conditions have made this necessary. After completing the count, the researchers have in some years met at the small one Brodtkorpholmen (Råkoppisaari) for lunch and exchange of information about which birds have crossed the border. This is to avoid the same birds being counted on both sides of the border. During the return further south, only species, or flocks of species, are counted that have certainly not been recorded before. Finally, the results from the two boat teams are summarized in the Bjelkestua at Varlamasari. Then the Norwegian participants go back to the Norwegian side, and the border is closed.Citation(s)
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