Losing your home : temporal changes in forest landscape structure due to timber harvest accelerate Northern goshawk (Accipiter gentilis) nest stand losses

In Finland, forests are both one of the main national economic resources and the main source of biodiversity. Lack of detailed empirical evidence of how forestry affects biodiversity limits the development of sustainable forest management. Previous studies have found that the Northern goshawk (Accipiter gentilis) is a keystone species in mature coniferous boreal forests, and that its presence is associated with high local biodiversity. To understand how timber harvest affect goshawk nest-stand constancy and nest occupancy, we analyzed changes in nine landscape classes in two buffer zones (100 m, 250 m) around goshawk nests in Western Finland during 2005-2013. Patterns of nest occupancy and nest stand loss during 2005-2013 was compared with corresponding data from 1999-2005 to investigate possible long-term changes in the same. We found a positive connection between the proportion of mature spruce forest and nest occupancy. Nest stand constancy was at a lower level during 2005-2013 than during 1999-2005. This was mainly because of forest loss due to cutting of nest stands. Given that the loss of goshawk nest stands has accelerated and because timber harvest in the area was found to be specifically targeted towards forest types favoured by goshawks, forestry may have an even larger negative effect on biodiversity locally than previously thought given that goshawk nest stands are associated with high biodiversity. To render the Finnish forestry ecologically sustainable, we propose that protection of goshawk nest stands should be an integrated part of standard forestry practices in the future.Peer reviewe

Kort- och långsiktiga konsekvenser av födobegränsningar på slagugglans reproduktion

Life-history theory states that although natural selection would favour a maximisation of both reproductive output and life-span, such a combination can not be achieved in any living organism. According to life-history theory the reason for the fact that not all traits can be maximised simultaneously is that different traits compete with each other for resources. These relationships between traits that constrain the simultaneous evolution of two or more traits are called trade-offs. Therefore, during different life-stages an individual needs to optimise its allocation of resources to life-history components such as growth, reproduction and survival. Resource limitation acts on these traits and therefore investment in one trait, e.g. reproduction, reduces the resources available for investment in another trait, e.g. residual reproduction or survival. In this thesis I study how food resources during different stages of the breeding event affect reproductive decisions in the Ural owl (Strix uralensis) and the consequences of these decisions on parents and offspring. The Ural owl is a suitable study species for such studies in natural populations since they are long-lived, site-tenacious, and feed on voles. The vole populations in Fennoscandia fluctuate in three- to four-year cycles, which create a variable food environment for the Ural owls to cope with. The thesis gives new insight in reproductive costs and their consequences in natural animal populations with emphasis on underlying physiological mechanisms. I found that supplementary fed Ural owl parents invest supplemented food resources during breeding in own self-maintenance instead of allocating those resources to offspring growth. This investment in own maintenance instead of improving current reproduction had carry-over effects to the following year in terms of increased reproductive output. Therefore, I found evidence that reduced reproductive costs improves future reproductive performance. Furthermore, I found evidence for the underlying mechanism behind this carry-over effect of supplementary food on fecundity. The supplementary-fed parents reduced their feeding investment in the offspring compared to controls, which enabled the fed female parents to invest the surplus resources in parasite resistance. Fed female parents had lower blood parasite loads than control females and this effect lasted until the following year when also reproductive output was increased. Hence, increased investment in parasite resistance when resources are plentiful has the potential to mediate positive carry-over effects on future reproduction. I further found that this carry-over effect was only present when potentials for future reproduction were good. The thesis also provides new knowledge on resource limitation on maternal effects. I found that increased resources prior to egg laying improve the condition and health of Ural owl females and enable them to allocate more resources to reproduction than control females. These additional resources are not allocated to increase the number of offspring, but instead to improve the quality of each offspring. Fed Ural owl females increased the size of their eggs and allocated more health improving immunological components into the eggs. Furthermore, the increased egg size had long-lasting effects on offspring growth, as offspring from larger eggs were heavier at fledging. Limiting resources can have different short- and long-term consequences on reproductive decisions that affect both offspring number and quality. In long-lived organisms, such as the Ural owl, it appears to be beneficial in terms of fitness to invest in long breeding life-span instead of additional investment in current reproduction. In Ural owls, females can influence the phenotypic quality of the offspring by transferring additional resources to the eggs that can have long-lasting effects on growth.Teorin om livshistoriors evolution baserar sig på att alla egenskaper hos en individ som genom naturligt urval skulle gynna individens duglighet inte kan maximeras på en gång. Därmed måste individen under olika livsskeden optimera hur den ska fördela sina resurser i olika livshistoriekomponenter, såsom tillväxt, förökning och överlevnad. Denna avvägning av att investera resurser i olika livshistoriekomponenter under olika skeden av individens livshistoria antas därmed vara beroende av födoresurser och andra miljöfaktorer. En investering i en livshistoriekomponent, t.ex. förökning, reducerar därför enligt teorin individens framtida förökningsmöjligheter eller överlevnad. I min avhandling undersöker jag experimentellt genom stödutfodring hur födoresurser påverkar slagugglans (Strix uralensis) förökningsbeslut och konsekvenserna av dessa under olika skeden av dess livshistoria. Slagugglan lämpar sig väl som modellorganism för dylika undersökningar i naturen eftersom den är långlivad, platstrogen och dess stapelföda är sork. Sorkstammen varierar kraftigt mellan åren och bildar tre- till fyraåriga populationscykler. Slagugglan är därför tvungen att anpassa sin förökning till dessa variationer i födotillgångar, vilket förutspår att dess livshistoria i stor utsträckning är födobegränsad. Avhandlingen ger nya insikter i förökningskostnader och deras kort- och långsiktiga konsekvenser i naturliga djurpopulationer med betoning på fysiologiska mekanismer. Jag fann bland annat att slaguggleföräldrar investerar stödutfodrade födoresurser under häckningen i sitt eget välbefinnande istället för att fördela resurserna till ungarnas tillväxt. Denna investering av föräldrarna i eget välbefinnande istället för att investera i den rådande häckningen hade långvariga konsekvenser och resulterade i att de föräldrar som fått tilläggsföda kunde öka sin ungproduktion följande år. Därmed fann jag bevis för att förminskade förökningskostnader kan ha långvariga konsekvenser genom att förbättra framtida förökningsutsikter. Jag fann ytterligare nya bevis för mekanismen som ligger bakom denna långvariga konsekvens av tilläggsföda på framtida förökningsframgång. De stödutfodrade slaguggleföräldrarna reducerade sin matningsinsats i ungarna jämfört med icke-matade föräldrar, vilket möjliggjorde att de matade föräldrarna investerade de insparade resurserna på immunförsvar mot blodparasiter. Blodparasitmängden hos slagugglehonorna minskade som följd av stödutfodringen och bibehölls på lägre nivå än hos kontrollhonorna ända till följande häckningssäsong. Ökad investering i parasitmotstånd verkade därför möjliggöra ökad framtida förökningsinsats. Jag fann också att denna långtidseffekt av tilläggsföda på framtida förökningsframgång endast verkar vara uppenbar då de framtida förökningsmöjligheterna är goda. Avhandlingen ger även ny insyn i födoresursernas roll vid avvägningen mellan avkommans antal och kvalitet. Jag fann att slagugglehonor som stödutfodrades före häckningen uppnådde bättre hälsa och hade mera resurser som de kunde tillägna förökningen jämfört med kontrollhonorna. Slagugglehonorna satte inte dessa ökade födoresurser på antalet ägg utan istället lade stödutfodrade honor betydligt större ägg som innehöll mera hälsobefrämjande immunförsvarskomponenter i äggen än honor som inte stödutfodrats. Jag fann också att den ökade äggstorleken i stödutfodrade honors kullar hade en långvarig positiv inverkan på ungarnas tillväxt: ungarna som härstammade från större ägg var i bättre kondition när de lämnade boet. Begränsade födoresurser kan ha olika kort- och långsiktiga konsekvenser för förökningsbeslut som påverkar både avkommans antal och kvalitet. Hos långlivade organismer såsom slagugglan verkar dugligheten maximeras genom att investera överloppsresurser i eget välbefinnande och därmed i antalet förökningsgånger istället för att ytterligare investera i det rådande förökningsförsöket. Hos slagugglan kan honor påverka avkommans kvalitet genom att fördela mera resurser i äggen som kan ha långvariga effekter under avkommans tillväxt.Väitöskirjani käsittelee evoluutioekologian keskeistä aihetta, lisääntymisen kustannuksia ja niiden mekanismeja. Teoria elämänkaarten evoluutiosta pohjautuu väittämään, että kaikkia yksilön luonnonvalinnan kautta kelpoisuutta suosivia ominaisuuksia ei voida maksimoida samanaikaisesti. Täten yksilön pitää elämänkaaren eri vaiheissa optimoida, miten se kohdentaa resurssinsa eri elämänkaaren osatekijöihin, kuten kasvuun, lisääntymiseen ja omaan selviytymiseen. Resurssien kohdentamisen oletetaan riippuvan ravinnosta ja muista ympäristötekijöistä. Investointi yhteen elinkaaren osatekijään, esim. lisääntymiseen, huonontaa siksi teorian mukaan yksilön tulevaa lisääntymistä tai selviytymistä. Väitöskirjassani olen kokeellisesti tutkinut lisäravinnon vaikutuksia viirupöllön (Strix uralensis) liisääntymispäätöksiin ja niiden seurauksiin elämänkaaren eri vaiheissa. Viirupöllö sopii hyvin mallieliöksi tämänkaltaisiin tutkimuksiin luonnonpopulaatioissa, koska se on pitkäikäinen, paikkauskollinen ja se syö pääravintonaan myyriä. Myyräkantojen raju vuosien välinen vaihtelu muodostaa kolme – neljävuotisia populaatiosyklejä. Viirupöllön on tällöin sopeutettava lisääntymisensä näihin ravinnon vaihteluihin, mistä vuorostaan seuraa, että viirupöllön elämänkaari on ravintorajoitteinen. Havaitsin tutkimuksissani, että viirupöllöemot investoivat pesinnän aikana annettua lisäravintoa omaan hyvinvointiin sen sijaan että ne kohdentaisivat lisäresurssit nykyisen pesinnän parantamiseen. Omaan hyvinvointiin panostamisella oli lisäruokintakokeessani pitkäaikaisia vaikutuksia seuraavan vuoden pesintään, jolloin lisäravintoa saaneet viirupöllövanhemmat munivat enemmän munia kuin verrokit. Pienentyneet pesintäkustannukset lisäravinnon avulla paransivat siis tulevaa pesintämenestystä. Lisäksi löysin uusia todisteita mekanismista, joka saattaa välittää tätä lisäravinnon avulla parannettua tulevaa pesintämenestystä. Lisäravintoa saaneet viirupöllöemot vähensivät poikasruokintapanostustaan, joka mahdollisti panostuksen omaan hyvinvointiin, kuten loisvasustuskykyyn. Veriloistaakka lisäravintoa saaneissa pöllöemoissa vähentyi verrokkiin verrattuna lisäravinnon seurauksena ja säilyi alhaisemmalla tasolla ensi vuoden pesintään asti. Parantunut veriloisvastustuskyky näyttää täten mahdollistavan suuremman investoinnin seuraavan vuoden lisääntymiseen. Väitöskirjani antaa uutta tietoa ravinnon merkityksestä emojen investoinnin suhteuttamisesta jälkeläisten lukumäärään ja laatuun. Havaitsin, että ennen pesintää ruokitut emot olivat terveempiä ja paremmassa kunnossa kuin verrokit. Lisäruokinta auttoi emoja kohdentamaan enemmän resursseja jälkeläistuottoon. Ruokitut viirupöllöemot eivät lisäresurrsien turvin munineet suurempia pesyeitä vaan suurempia munia, jotka sisälsivät enemmän terveysvaikutteisia vasta-aineita kuin verrokkien munat. Emolle annettu lisäruoka vaikutti epäsuorasti jopa poikasten kasvuun, koska isommista munista kuoriutuneet poikaset olivat paremmassa kunnossa lentopoikasvaiheessa. Rajallisella ravinnolla voi olla erilaisia lyhyt- ja pitkäaikaisseurauksia lisääntymispäätöksiin, jotka vaikuttavat sekä jälkeläisten määrään että laatuun. Pitkäikäiset eliöt, kuten viirupöllöt, näyttävät maksimoivan evolutiivista kelpoisuuttaan investoimalla ylimääräisiä resursseja omaan hyvinvointiinsa ja siten pesintöjen lukumäärään sen sijaan että ne panostaisivat vielä enemmän nykyiseen lisääntymisyritykseen. Ennen pesintää käytössä olevat resurssit vaikuttavat suoraan jälkeläisten laatuun, koska hyvissä ravinto-olosuhteissa muniin siirtyy enemmän resursseja joilla voi olla vaikutuksia jälkeläisten kasvun aikana

To breed or not to breed: drivers of intermittent breeding in a seabird under increasing predation risk and male bias

Intermittent breeding may be adaptive for long-lived species subjected to large accessory reproductive costs, but it may also reflect reduced adaptation to the environment, reducing population growth. Nevertheless, environmental influences on breeding propensity, particularly that of predation risk, remain poorly understood and difficult to study, because non-breeders are typically not identified. Female eiders Somateria mollissima from the Baltic Sea provide an excellent testbed, because nesting females have been exposed to intensifying predation and growing male bias that may increase female harassment. We based our study on long-term data (14 years) on females captured and marked at the nest, and females individually identified at sea irrespective of capture status. We hypothesized that breeding propensity decreases with increasing predation risk and male bias, and increases with breeder age. Consistent with our hypotheses, females nesting on islands with higher nest predation risk were more likely to skip breeding, and breeding probability increased with age. In contrast, the steep temporal decline in breeding propensity could not be reliably attributed to annual adult sex ratio or to the abundance of white-tailed sea eagles (Haliaeetus albicilla), the main predator on females, at the nearby Hanko Bird Observatory. Breeding probability showed significant consistent individual variation. Our results demonstrate that spatiotemporal variation in predation risk affects the decision to breed and high incidence of non-breeding was associated with low fledging success. The increased frequency of intermittent breeding in this declining population should be explicitly considered in demographic models, and emphasis placed on understanding the preconditions for successful reproduction.Peer reviewe

Striving with Global Stress on a Local Level: Has the COVID-19 Pandemic Changed the Relationship between People and Nature?

The COVID-19 pandemic had harsh consequences on human health and society across the globe. In addition to health effects, the pandemic also influenced people's values, concerns, and ethics due to lockdowns and general limitations in societal activities. In this study, we examined changes in the relationship between people and nature caused by COVID-associated stress, as well as its consequences on life quality, by comparing questionnaire-based survey data before and during the pandemic. We found that the pandemic had positive effects on individual respondents' relationships with nature. Respondents who were more affected by the pandemic rated their life quality lower than those who were less affected. In accordance, the pandemic had a negative effect on people's life quality, especially for people living in areas where the environment (coastal water quality) was in poor condition. Our results support the prediction that environmental quality may buffer against global stress and improve societal wellbeing

To breed or not to breed: drivers of intermittent breeding in a seabird under increasing predation risk and male bias

 Intermittent breeding may be adaptive for long-lived species subjected to large accessory reproductive costs, but it may also reflect reduced adaptation to the environment, reducing population growth. Nevertheless,environmental influences on breeding propensity, particularly that of predation risk, remain poorly understood and difficult to study, becausenon-breeders are typically not identified. Female eiders Somateria mollissimafrom the Baltic Sea provide an excellent testbed, because nesting females have been exposed to intensifying predation and growing male bias that may increase female harassment. We based our study on long-term data (14 years) on females captured and marked at the nest, and females individually identified at sea irrespective of capture status. We hypothesized that breeding propensity decreases with increasing predation risk and male bias, and increases with breeder age.Consistent with our hypotheses, females nesting on islands with higher nest predation risk were more likely to skip breeding, and breeding probability increased with age. In contrast, the steep temporal decline in breeding propensity could not be reliably attributed to annual adult sex ratio or to the abundance of white-tailed sea eagles (Haliaeetus albicilla),the main predator on females, at the nearby Hanko Bird Observatory. Breeding probability showed significant consistent individual variation.Our results demonstrate that spatiotemporal variation in predation riskaffects the decision to breed and high incidence of non-breeding was associated with low fledging success. The increased frequency of intermittent breeding in this declining population should be explicitly considered in demographic models, and emphasis placed on understanding the preconditions for successful reproduction.</p

How accurate is citizen science? Evaluating public assessments of coastal water quality

Citizen science is changing society's contribution to research projects worldwide. Non-experts are no longer just spectators, they are active participants and supporters of scientific work. Using citizen science, that is, data collected by laypeople, the opportunities to collect large-scale data on the environment are increasing. Such community-based and citizen scientific approaches can provide useful tools as local people can be trained to accurately take measurements that can be used in scientific studies. However, little is known about how well volunteer-based non-standard subjective assessments of the environment based on prior experience only and no training compare with scientifically measured estimates of that environment. In this paper, we tested how well measures of coastal water quality assessed by local inhabitants corresponds with objective water quality data collected using scientific instruments. Our results showed that over 70% of the respondents assessed water quality in the right direction and almost 60% were correct in their estimates. We found that socio-demographic factors affect the assessments, but do not markedly improve reliability. We conclude that simple questionnaires can be used to assess general coastal water quality.</p

Does Water Quality Matter for Life Quality? A Study of the Impact of Water Quality on Well-being in a Coastal Community

Most studies of life quality are concentrated on a country-level scale, while local differences within a country or area are less studied. Thus, the effect of the environment on life quality on a local scale remains understudied and is often represented by one generalized common factor. In this study, we investigated the effect of an objectively measured environmental quality variable and subjective reflections of this (perceptions of environmental quality) in relation to life quality in a coastal community. Hence, we tested the effect of objective and subjective water quality measures using a model, accounting for other traditional variables (e.g., income and health) that predict life quality variations. Our findings indicate that perceptions of the environment are strongly associated with life quality, whereas objectively measured environmental quality is associated with life quality to a lesser extent. Thus, our results suggest that the impact of the environment on life quality is mediated via the way the environment is perceived (psychological effects) and less by the actual conditions of the environment

Increased male bias in eider ducks can be explained by sex-specific survival of prime-age breeders

In contrast to theoretical predictions of even adult sex ratios, males are dominating in many bird populations. Such bias among adults may be critical to population growth and viability. Nevertheless, demographic mechanisms for biased adult sex ratios are still poorly understood. Here, we examined potential demographic mechanisms for the recent dramatic shift from a slight female bias among adult eider ducks (Somateria mollissima) to a male bias (about 65% males) in the Baltic Sea, where the species is currently declining. We analysed a nine-year dataset on offspring sex ratio at hatching based on molecularly sexed ducklings of individually known mothers. Moreover, using demographic data from long-term individual-based capture-recapture records, we investigated how sex-specific survival at different ages after fledgling can modify the adult sex ratio. More specifically, we constructed a stochastic two-sex matrix population model and simulated scenarios of different survival probabilities for males and females. We found that sex ratio at hatching was slightly female-biased (52.8%) and therefore unlikely to explain the observed male bias among adult birds. Our stochastic simulations with higher survival for males than for females revealed that despite a slight female bias at hatching, study populations shifted to a male-biased adult sex ratio (> 60% males) in a few decades. This shift was driven by prime reproductive-age individuals(>5-year-old), with sex-specific survival of younger age classes playing a minor role. Hence, different age classes contributed disproportion ally to population dynamics. We argue that an alternative explanation for the observed male dominance among adults sex-biased dispersal can be considered redundant and is unlikely, given the ecology of the species. The present study highlights the importance of considering population structure and age-specific vital rates when assessing population dynamics and management targets

Fledging Mass Is Color Morph Specific and Affects Local Recruitment in a Wild Bird

Early-life conditions may have long-lasting effects on life history. In color polymorphic species, morph-specific sensitivity to environmental conditions may lead to differential fitness. In tawny owls (Strix aluco), pheomelanin-based color polymorphism is expected to be maintained because the brown morph has higher adult fitness in warmer environments, while selection favors the gray morph under colder conditions. Here we investigate body mass at fledging and its consequences until adulthood in a population at the species' cold range margin. Using 40 years of data (1979-2017), we show that brown pairs, which mainly produce brown offspring consistent with a one-locus-two-alleles inheritance model, consistently raised heavier offspring than mixed (gray-brown) pairs and gray pairs. Offspring mass declined seasonally, except among offspring raised by brown pairs. Brown offspring could be heavier because of morph-specific parental care and/or offspring growth. Furthermore, mass at fledging is associated with fitness: the probability of local recruitment into the breeding population increased with higher mass at fledging, especially in mild winters and with favorable food conditions, although recruitment is not morph specific. Fledgling mass thus provides a fitness benefit in terms of recruitment probability that is modulated by environmental factors, which appear to level off any direct morph-specific recruitment benefits

Cold winters have morph-specific effects on natal dispersal distance in a wild raptor

Dispersal is a key process with crucial implications in spatial distribution, density, and genetic structure of species' populations. Dispersal strategies can vary according to both individual and environmental features, but putative phenotype-by-environment interactions have rarely been accounted for. Melanin-based color polymorphism is a phenotypic trait associated with specific behavioral and physiological profiles and is, therefore, a good candidate trait to study dispersal tactics in different environments. Here, using a 40 years dataset of a population of color polymorphic tawny owls (Strix aluco), we investigated natal dispersal distance of recruiting gray and pheomelanic reddish-brown (hereafter brown) color morphs in relation to post-fledging winter temperature and individual characteristics. Because morphs are differently sensitive to cold winters, we predicted that morphs' natal dispersal distances vary according to winter conditions. Winter temperature did not affect the proportion of brown (or gray) among recruits. We found that dispersal distances correlate with winter temperature in an opposite manner in the two morphs. Although the gray morph undertakes larger movements in harsher conditions, likely because it copes better with winter severity, the brown morph disperses shorter distances when winters are harsher. We discuss this morph-specific natal dispersal pattern in the context of competition for territories between morphs and in terms of costs and benefits of these alternative strategies. Our results stress the importance of considering the interaction between phenotype and environment to fully disentangle dispersal movement patterns and provide further evidence that climate affects the behavior and local distribution of this species.In species displaying alternative colorations (morphs), climate may induce different responses according to the intensity of pigmentation. We show that brown, more pigmented, tawny owls tend to move away farthest from their place of birth in milder winters, whereas paler gray tawny owls move farthest in colder winters. The ongoing changes in winter severity will likely affect differently movement patterns of these two tawny owl color morphs, with important consequences on morph distribution and population dynamics