The status, structure and behaviour of populations of the wolf (Canis l. lupus L.) along the Fenno-Soviet border

1. What they did

Wolves once lived throughout Finland, but by 1900 they bred only in the east and north. Since 1950 Finland had seen two waves of wolves coming in from the east, mainly from Soviet Karelia: the first in 1959 to 1963 and the second beginning in 1975. The author set out to record the status, structure and behaviour of wolf populations along the Finnish-Soviet border.

• Border crossings. At the author’s suggestion, the Finnish Border Patrol Establishment recorded every crossing of the frontier by wolves and other large predators on its daily patrols along a 2574 km observation line, from 1968 to 1979. Crossings were identified mainly from tracks in snow, and also in sandy, wet or muddy ground.
• Population estimates. Three times a year (1 January, 1 June and 1 October) the patrols estimated the number of wolves in a zone at least 20 km wide along the frontier.
• Dead wolves. Information on all wolves killed and found dead in Finland was gathered through every available channel, and their sex and age recorded.
• Soviet data. The author compared the Finnish records with published Soviet track counts, made by skiing along observation lines and counting wolf tracks crossing them, and with Soviet population figures.

2. What they found

Border crossings

• The patrols recorded 4023 wolf crossings in 1968 to 1978: 99.6% on the border with the USSR, 14 on the Norwegian frontier and two on the Swedish frontier.
• Crossings ran at 70 to 115 a year in 1968 to 1972, then rose sharply from 129 in 1974 to 1259 in 1977, especially in Northern Karelia and southern Kainuu. They fell in 1978 and in early 1979, suggesting 1977 was the peak of this expansion.
• Crossings in Finnish Northern Karelia rose alongside Soviet track counts in the neighbouring part of Soviet Karelia.

How many wolves

• On 1 January, patrols estimated 6 to 24 wolves near the frontier in 1969 to 1975, rising to between 77 and 89 in 1978 and falling to between 63 and 70 in 1979.
• These wolves moved near the border in units of 1 to about 10, and may have crossed it almost daily. When pursued on the Finnish side, they retreated to the Russian side.
• Inland, wolves moved in units of 1 to 4 along old migration routes, and from 1970 they were seen in western and southern Finland. Adding about 30 wandering wolves, Finland had about 100 wolves at the start of 1979.

Sex and age of dead wolves

• Of 123 dead wolves sexed in 1969 to 1979, 65.8% were males, a highly significant excess. The excess was larger in 1968 to 1975 (38 of 48, almost 80%) than in 1976 to 1979 (43 of 75, 57.3%, not significant).
• In Northern Karelia, the first expansion gave an even sex ratio; in the Savukoski-Kuhmo district there was an excess of males. In Northern Karelia there were five males and one female in 1972 to 1975, but an even 16 to 15 in 1976 to 1979.
• Of 29 pups aged 4 to 10 months killed in 1969 to 1979, 17 were males (58.6%, not significant). Adults from the same packs were also killed in several cases.

Soviet populations

• Soviet track counts were highest in southern and central Soviet Karelia, where moose and reindeer were abundant, and lower in the north-east.
• Before 1940 wolves were rare in northern Soviet Karelia. From the late 1940s clear-cutting replaced conifers with deciduous trees, moose increased, and reindeer were no longer herded or hunted. Wolves could move freely along forest roads, ungulate trails and other paths, and they spread north.
• Soviet track counts tripled from 1966 to 1969 (0.2 tracks per 10 km) to 1973 to 1976 (0.7 tracks per 10 km). The author estimates 800 to 900 wolves in Soviet Karelia at the 1976 peak; 151 were killed there in the 1978 hunting season. About 500 wolves were reported in the Leningrad region in 1978.

3. What they concluded

• The crossing records give a reliable picture of relative changes in wolf movement, but not of actual numbers, because one wolf may cross many times, and few crossings can be seen in the snowless season.
• The crossing data agree fairly well with what is known of wolf numbers beyond Finland’s borders. Wolves were nearly absent on the Swedish and Norwegian frontiers, but more than 4000 crossings were recorded on the eastern frontier.
• Wolf numbers in Soviet Karelia and the Leningrad region grew very fast. The author suggests this is because continuous hunting disturbs the pack’s self-regulation: normally the dominant pair suppresses breeding by other females, and hunters most often kill the dominant pair, which allows the pack to reach its maximum productivity.
• The author estimates that, under present conditions, the Soviet Karelian wolf population reaches saturation at roughly 5 to 7 wolves per 1000 km², and then disperses into empty suitable areas such as Finland. More use of forest roads and ungulate trails in deep snow may lead to more encounters between wolf units, more movement and more dispersal.
• In both expansions most wandering wolves were males, and the excess of males fell as the breeding population came closer to the frontier. Both expansions were blocked by killing (at least 72 wolves were killed in 1977 to 1979).
• Packs of more than five have been seen only in easternmost Finland. Groups reaching the west and south (1 to 4 wolves) were probably low-ranking adults and young animals. None has been recorded returning, which suggests real dispersal and that they found suitable habitat and food.

4. How tracking was or was not used

Tracking was the main source of the population data. Border patrols recorded wolf crossings of the frontier from their tracks, mostly in snow but also in sandy, wet or muddy ground. Patrol estimates of wolf numbers were most reliable on 1 January, in the snowy season. The Soviet data came from track counts: observers skied along observation lines and counted wolf tracks crossing them, expressed as tracks per 10 km. The author notes that snow cover lasts much longer in the north than in the south-east, which must be kept in mind when reading the crossing data.

5. Tracker or observer certification

Reported but not validated. Members of the Border Patrol Establishment are taught to recognize the tracks of wolves and other large predators during their preliminary training. No test of their skill is reported. Nothing is said about who made the Soviet track counts.

6. Other technologies, skills or innovations

• Using daily border patrols as a long-term, country-wide monitoring line for large predators, with population estimates three times a year.
• Combining track-based crossing records with kill records (sex and age of dead wolves) and neighbouring countries’ track counts.

7. Implications for conservation (from the paper)

• Continuous hunting may make a wolf population grow faster, by removing the dominant pair and allowing more females to breed.
• Wolves could probably soon regain their former range in Finland, even in settled southern areas, if not for busy roads and unintentional disturbance by people. They were protected in southern Finland from September 1973 to the end of 1977.
• Both expansions into Finland were blocked by killing.