Sami Kurki

LANDSCAPE FRAGMENTATION AND FOREST COMPOSITION EFFECTS ON GROUSE BREEDING SUCCESS IN BOREAL FORESTS

We examined the breeding success of forest grouse in relation to anthropogenic forest fragmentation in Finland. Employing Geographic Information Systems (GIS) and grouse data derived from Finnish wildlife triangle censuses conducted during 1989–1994, we combined the locations of 2267 Black Grouse (Tetrao tetrix) and 1060 Capercaillie (T. urogallus) females after the breeding season in mid-August with landscape data. The indicators of breeding success were the proportion of grouse hens with a brood and brood size. Two study areas (each 45 000 km2) in the boreal zone were selected for investigation. The breeding success of grouse was negatively correlated with both fragmentation of forest area per se by farmland and the decreasing proportion of older forest as a result of clear-cutting. The extent of landscape accounting best for variation in nesting success was an order of magnitude larger (∼100 km2) than the area most probably used by a grouse female and her brood during the summer, which suggests that la...

Abundances of red fox and pine marten in relation to the composition of boreal forest landscapes.

The effects of human-caused fragmentation of boreal forest on the abundance of red fox Vulpes vulpes L. and pine marten Martes martes L. were studied by combining the Finnish wildlife-triangle snow-track data (1990-94) with land-use and forest resources data employing the GIS. Two study areas (each 45 000 km(2) ) located in northern and southern Finland were selected for the investigation. The extent of landscape that best explained predator abundance (tracks per 10 km 24 h(-1) ) was the same (about 100 km(2) ) in both species and study areas. The decreasing proportion of older forest and the increasing proportions of young forest and agricultural land in the landscape positively affected track density of red fox. The relationship between agricultural land and fox abundance, however, was characterized by a convex curve peaking at 20-30% of agricultural land. With the habitat classification used, landscape composition explained 26% and 11% of the spatial variation in fox abundance in the northern and southern study area, respectively. The relationship between landscape composition and pine marten abundance was not as clear as in that of red fox. Landscape composition explained 10% and 6% of spatial variation in pine marten abundance in the northern and southern study area, respectively. In both areas a positive impact occurred with the increasing proposition of young forest in the landscape, but in the northern area the negative effect of increasing proportion of agricultural land was dominant. The abundances of red fox and pine marten were not negatively correlated, indicating that competition or intraguild predation by red fox do not determine abundance of pine marten on a landscape scale. A general increase in predation pressure by generalist predators in fragmented forest landscapes has been an intensively discussed conservation problem during recent years. We conclude that the red fox is a species potentially able to cause elevated predation pressure in boreal landscapes fragmented by human activities, but that the evidence against the pine marten is weaker.

Human dimensions of wolf (Canis lupus) conflicts in Finland

The growth of the Finnish wolf (Canis lupus) population during the last years has highlighted people’s contradictory attitudes toward wolves. The supranational conservation objectives brought on by Finland’s membership in the European Union (EU) and the regional application of the official policy on wolves have led to conflicts. This article is based on the preparation process of the wolf management plan in Finland. As a part of the process, a nationwide hearing was arranged in 2004. Fear of wolves is widespread and even more common in areas with low wolf population. People living in areas where wolves occur feel that they can no longer influence decision making which affects them and that the authorities, conservationists, and the EU do not listen to their opinions. Numerous requests have been made for the legislation and its interpretation, and concessions to these requests would promote consensus and increase tolerance for wolves. Proposed changes include reforming the damage compensation system and formulating a clearer interpretation of the conservation status of wolves. However, it seems impossible to create a policy that would be universally supported. As the wolf question has become more central in environmental policy, the conservation and management of the species have become more complicated, and the cooperation between various interest groups has declined. The wolf conflict could be mitigated by compromises, but because the conflict is value-based, solutions are illusive.

The good bad wolf—wolf evaluation reveals the roots of the Finnish wolf conflict

This article focuses on the roots of the Finnish wolf conflict by using stakeholder evaluations of the wolf as a tool. The recent growth of the wolf population has highlighted stakeholders’ contradictory objectives and revealed a conflict between the two main stakeholders, conservationists and hunters, in wolf management. The question of hunting emerges as the core of the conflict. The negative evaluation of the wolf by hunters reflects a competitive situation, which is typical of the historical development of wolf management in Finland. In areas with the most abundant wolf populations, hunters view the wolf most negatively. This study clearly demonstrates that the Finnish wolf conflict is rooted in the values of modern society and carries a long historical, practical and ecological background in which humans and wolves compete over resources, mainly the moose. The conflict between hunters and conservationists in wolf management is connected to the appreciation of moose as game and stems from competition between humans and wolves over their prey and the historical presence or absence of the wolf.

Strong community support for illegal killing challenges wolf management

In Finland, the conservation of large mammalian carnivores—brown bear, lynx, wolf and wolverine—is undermined by illegal killings that have commonly taken place after the implementation of national carnivore management plans. This hidden form of criminality cannot occur to such an extent without strong support from the local community. We examined the support of proximate groups by collecting data from hunters and women. In collecting data, we used non-active role playing with empathy-based fictitious stories. We used argumentation analysis to reveal the assumed species, the background of the illegal killing and especially the justifications and importance of community support for illegal killing. The results show that we have a conflict with strong basic emotions in hand as both illegal killing and support for illegal killing and hunting violators are based on anger and fear for children and domestic animals as well as frustration toward the authorities and the lack of proper management actions. The wolf is at the centre of the conflict due to the specific character of the species. Current policies have inevitably been lacking in terms of place-based policy, and that has led to conflicts between game management authorities/researchers and ordinary citizens. To facilitate a change in attitudes, we suggest focusing on affective factors via confidence-building measures.

Decreasing the fragmentation of old forests in landscapes involving multiple ownership in Finland: economic, social and ecological consequences

The management of biological diversity at the landscape level in Finland is complicated by the relatively small size of the holdings and the fact that the habitats of species do not necessarily follow the holding borders. Therefore, there is a great need to develop such forest-planning approaches that aim at solving the problems that some species have faced due to modern forestry, including the fragmentation of old forests. One way to deal with fragmentation is to aggregate old forests into larger patches, a goal that may be achieved by excluding some areas from forestry operations or by restricting the intensity of treatments. In a planning area under multiple ownership, the sizes, shapes and relative locations of set-aside areas are important, since they affect the social equity of the proposed forest plans. In this study, the effects of two conflicting goals, i.e. the improvement of old-forest patterns, and the equal participation of forest owners were studied in a privately owned forest area in Finland. This was made possible through the examination of the consequences of alternative strategies to delineate areas set aside. The two main results of the study were, first, that it is difficult to reach these goals simultaneously, and, second, the time interval relevant in the management planning of private forestry is quite short with respect to efforts to change landscape structure significantly. However, in real planning situations, it is important to specify the locations of forest holdings whose owners are willing to acknowledge biodiversity values above the level defined in the legislation. In addition, ecologically important areas should be located and connected to the above information. According to the results of this study, it seems that a compensation system would facilitate the restructuring of the forest landscapes towards an ecologically enhanced structure.

Change in the sex ratio of the Finnish capercaillie Tetrao urogallus population

Earlier reports from Fennoscandia and Russia have shown that among adult capercaillies the proportion of females is 60–65%, mainly as a consequence of high mortality of male chicks during their first months of life. The Finnish August censuses of grouse (1964–1988) show that the percentage of female capercaillie has remained unchanged at about 60–65% in northern and eastern Finland. Over the same period the percentage of females in southern and central Finland has decreased significantly from 62 to 50%. The present geographical variation in the percentage of females seems to coincide with the amount of forest in the landscape; the proportion of females is lowest in the southern and western part of Finland where the proportion of agricultural land is highest. Data from 1989–1996 show that variation in August male density among game management districts in Finland (CV%: 21.9) is significantly smaller than that of females (CV%: 33.4). This suggests that the variation in female proportion is more dependent on variation in female than in male density. The most probable reasons for the change in sex ratio include predation on females by mammalian and avian predators and selective hunting (or closing of hunting seasons), but tests of these hypotheses are premature at present.

Long-term change in territory occupancy pattern of goshawks (Accipiter gentilis)

Abstract: We examined territory occupancy (n = 161; 720 breeding attempts) of northern goshawks (Accipiter gentilis) in western Finland in 1983–1996. Nest sites of goshawks were characterized by old forests. The proportion of longstanding goshawk territories declined steeply from the beginning of the 1990s, while occasionally occupied goshawk territories became common. We suggest that the longstanding occupancy of the same territory, typical for goshawks, has decreased at least partly because of the logging of mature forests, which are preferred nesting habitats of goshawks. The mean occupancy rate of all goshawk territories, however, did not change through the study period, which suggests that the size of the breeding population has been constant.

Clear-cut areas and breeding success of Tengmalm's owls Aegolius funereus

The effect of mature forest fragmentation on breeding success of vole-eating Tengmalms owls Aegolius funereus was studied in western Finland during 1981–1995. The owl pairs produced more fledglings in territories with high (>30%) proportions of clear-cut and plantation areas than in territories with low (<30%) proportions of such areas. Territory occupancy, clutch size, laying date, and parental characteristics such as wing length, body mass and age were not associated with the proportion of clearcut areas within territories. Snap-trapping data from the ‘increase’ vole year 1994 revealed that the Microtus vole density tended to be higher in large clear-cuttings than in small ones. The increasing amount of sapling and clear-cut areas in coniferous forests during the last three decades has created suitable grass habitats for Microtus voles, and simultaneously new hunting habitats for Tengmalms owls. Therefore, forest fragmentation due to clear-cuttings may benefit Tengmalms owls at the present scale. However, nest-boxes should be erected and old groves should be protected, because forest harvesting apparently reduces the number of suitable natural cavities for owls in the long run.

Observations on the flocking and mobility of Capercaillie (Tetrao urogallus) – hunters' fairytales or true observations?

Flocking is a common phenomenon in birds. According to koskiMies (1957) “a flock in a broad sense may consist of socially independent birds congregating around a common feeding place or any other item of mutual interest. However, in most cases, the aggregation is assumed to be formed as a result of interindividual social attraction”. Breeding pairs and parent-young family groups may be excluded from the definition of a flock (eMlen 1952). Many bird species live in flocks all year round. Some species aggregate for breeding (colonies), for temperature regulation (huddling) or for feeding. To live in a group may protect from predation (alertness, dilution-effect) and ensure feeding possibilities. Lekking may enhance possibilities for mating. The mobility of birds is commonly described by the words “migration” and “dispersal” (Greenwood 1980). “Migration” describes seasonal movements of birds between their wintering and breeding sites, whereas “natal dispersal” means the movements of birds from their site of birth to the site where they will reproduce, and “breeding dispersal” the movement of adults between breeding attempts. In birds, in general, females disperse longer distances than males and juveniles longer than adults (Greenwood 980, clarke et al. 1997). Grouse species are commonly taken as poor dispersers with the female being the most dispersing sex (schroeder 985, swenson 99 , storch 997, warren & Baines 2002). Capercaillie (Tetrao urogallus) is a lekking species, but aggregations outside leks have also been reported in Finland (weckMan 904, Virkkula 943, koskiMies 957, Pulliainen 982, Bisi 1999). Both females and males may undertake seasonal movements of varying distances (rolstad et al. 988, helle et al. 990, hJelJord et al. 2000). The data from ringed capercaillies in Finland is limited, but some movements of 20-45 km have been recorded (renGastustoiMisto 2003, data from the Ringing Centre, Finnish Museum of Natural History). In craMP & siMMons (1980) movements of more than 1000 km were mentioned. Some occasional observations on flocking and mobility of the capercaillies and the descriptions of these phenomena in Finnish wildlife literature (weckMan 904, Virkkula 943, koskiMies 957, Pulliainen 982, Bisi 1999) formed the background of this study. To examine occurrence of flocking and occasional mobility, an enquiry approach was taken. In this study we wanted to examine (1) the usefulness of existing observations on an occasional phenomenon when field observations may be difficult to collect, and (2) the occurrence of occasional flocking and the mobility of the capercaillie. We also wanted to (3) discuss the reliability of such observations. In this paper we will use the terms “flock” and “flocking” to describe the occasional accumulation of capercaillies outside the lekking period and “mobility” to describe capercaillie movements.