Large carnivores are in decline throughout their range primarily due to anthropogenic influences. This is a concern because these species have high social, economic and ecological value. African lion (Panthera leo) populations are in decline in most parts of the continent and this has been attributed largely to habitat loss, habitat fragmentation, wire snare poaching, black market trafficking in lion parts, retaliatory killings, and poorly regulated trophy hunting. In order to implement effective lion conservation actions, the effect of each factor on lion demography or population dynamics must be well understood. In the past, most studies have used indirect methods to quantify the effects of hunting on lion demography. The temporary ban on lion hunting in Zambia allowed me to study directly how removing a key source of mortality, for males in particular, changed the demography. Using data collected from 2008-2015, I studied how the lion population in and around South Luangwa National Park, Zambia responded to a 3-year moratorium on lion trophy hunting implemented in 2013. For the duration of the study ban, I monitored 386 known individuals in 19 prides and 15 male coalitions. Reproductive activity as represented by cub production appeared to improve after the hunting ban and the number of individually identifiable lions in the study area steadily increased from 88 in 2008 to 197 in 2015. Using a Cormack-Jolly-Seber model, I found that apparent annual survival increased in the absence of hunting for all adult male age classes. The temporary ban on hunting was lifted in 2016 and I recommend that quotas remain conservative in order to allow more time for the population to recover, particularly in the adult male age classes. Better monitoring protocols should also be implemented to promote compliance with hunting regulations.

No description available.

Abstract Climate change causes range expansions, but neither the population parameters nor the ecological mechanisms behind range expansions are well known. I studied population dynamics and demography of the great tit (Parus major) in northern Finland, close to the northern range margin of the species’ distribution. I further examined winter conditions, such as temperature, as limiting factors on winter site fidelity and survival of human-fed great tits. Temporal variation in the population growth rate was large, but indicated an overall increasing population size, which fits the current large scale increase in the north. Importantly, the study population was a sink (or pseudo-sink) in almost all years because of low adult survival and low local recruitment. Immigration formed 39–43% of the annual population growth rate indicating that the population is demographically dependent on immigration. The demography differs most from other great tit populations in terms of adult survival which is lower than estimates from more southern Europe. This difference may reflect the impact of more difficult winters. Results from the wintering population support this line of reasoning. Within-winter movement was lower during mid-winter (January to February) and decreased during cold periods. This pattern is probably linked to energy saving and predator escaping strategies during these demanding periods when energy expenditure is high and birds have limited daylight hours to forage. Site fidelity was lower for juveniles than adults within a winter, but not between winters. In addition, survival showed strong links to winter weather. There was temporal variation within winters, particularly when the winter was colder than usual. Survival of juveniles showed a stronger response to cold temperatures. When mean daily minimum temperatures declined below –15 C° degrees, survival started to decline. Low winter temperatures thus provide one explanation for the lower annual adult survival and the sink nature of the population. The results suggest that great tits suffer from the cold conditions of the north: higher mortality increases turnover allowing for strong immigration. Great tits should benefit from warming winters caused by climate change. / Tiivistelmä Väitöskirjassani tutkin talitiaisen (Parus major) populaatiodynamiikkaa, talviaikaista paikkauskollisuutta ja säilyvyyttä levinneisyysalueen pohjoisreunan läheisessä populaatiossa Oulussa. Aikuissäilyvyys oli vuosittain hieman alhaisempi kuin lajin ydinalueella Länsi-Euroopassa. Tutkimusalueella syntyneistä poikasista vain pieni osa jäi pesimään tutkimusalueelle, mikä heijastaa voimistunutta lähtömuuttoa huonolaatuiselta alueelta. Ajallinen vaihtelu populaation kasvukertoimessa oli suurta, mutta keskiarvo osoittaa nykyisen populaation kasvavan. Havaitsemani populaation kasvu ei selity kasvulla aikuissäilyvyydessä tai paikallisessa rekrytoinnissa. Oletan, että populaatio on ollut tulomuuton ylläpitämä nielu (tai valenielu) lähes kaikkina tutkimusvuosina. Niinpä populaatio on demografisesti ja geneettisesti riippuvainen ydinalueesta, josta tuleva geenivirta aiheuttaa ongelmia paikallisiin olosuhteisiin sopeutumisessa. Tutkin sekä talvensisäistä että talvien välistä paikkauskollisuutta suhteessa ikään, sukupuoleen, vuodenaikaan, lämpötilaan ja päivän pituuteen. Talvensisäinen liikkuvuus oli vähäisintä keskitalvella erityisesti kylmien jaksojen aikana. Tämä ilmiö on luultavasti yhteydessä energiansäästöön ja saalistajien välttelyyn näiden vaativien jaksojen aikana, jolloin energiankulutus on suurta ja valoisa ruokailuaika on lyhyt. Nuorten talvensisäinen paikkauskollisuus oli huonompi kuin aikuisten, mutta sukupuolten välillä tässä ei ollut eroa. Sen sijaan talvien välisessä paikkauskollisuudessa ei ollut ryhmien välisiä eroja, mikä viittaa paikkauskollisuudesta olevan yhtäläiset hyödyt kaikille. Nuoret luultavasti keräävät tietoa resursseista ensimmäisenä talvenaan ja täten hankkivat samat edut kuin aikuiset palatessaan alueelle seuraavana talvena. Tutkin, onko talvella lintujen ruokintapaikkoja hyödyntävien talitiaisten säilyvyydessä ympäristötekijöistä, kuten lämpötilasta, johtuvaa vaihtelua. Talvisäilyvyys vaihteli paljon etenkin tavallista kylmempänä talvena. Nuoret kärsivät eniten kylmistä lämpötiloista. Kun keskilämpötila laski –15 C°:seen tai sen alapuolelle, säilyvyys alkoi heikentyä. Verrattuna kylmään talveen säilyvyys oli 1,5 kertaa todennäköisempää lauhan talven aikana. Talitiaiset näyttävät kärsivän pohjoisen kylmistä olosuhteista: korkea kuolleisuus lisää vaihtuvuutta ja geenivirtaa, kun alueelle kohdistuu voimakasta tulomuuttoa.

Understanding the patterns and processes that create differences among individuals in components of fitness, like the probability of survival or reproductive rates, is essential to our knowledge of population dynamics and for informing conservation efforts. For organisms in seasonal environments, early-breeding individuals regularly attain higher fitness than their late-breeding counterparts. Two primary hypotheses, related to quality and date, have been proposed to explain lower reproductive success of late breeders, but the veracity of these ideas has not been fully resolved. I tested predictions associated with these hypotheses to assess the effects of indices of parental and environmental quality on nestling quality and survival in an insectivorous passerine, the tree swallow (Tachycineta bicolor), at two widely separated breeding locations in western Canada. I combined experiments and statistical modelling of observational data to evaluate two mechanisms proposed to contribute to seasonal decline in environmental quality: an increase in nest parasite abundance and a decrease in food abundance with later breeding dates. A parasite reduction experiment revealed a disproportionate benefit of parasite removal on length of primary feather for early-hatched nestlings, suggesting greater energetic constraints early in the breeding season. Furthermore, late-hatched nestlings from parasite-reduced nests had longer head-bill lengths than their control counterparts, and developed head-bills of similar length to those of early-hatched nestlings. Other than these findings, there were few detectable effects of parasites on nestling size, growth and immunity, as has been reported from several previous studies. Indeed, negative effects of parasites were only apparent when food (i.e., insect) biomass was considered. In a second series of experiments in which parental quality was controlled, I also tested whether food abundance declined during the breeding season, as predicted if environmental conditions deteriorate seasonally (i.e., date). Reduced reproductive success of late-breeding individuals was causally related to a seasonal decline in environmental quality. Declining insect biomass and enlarged brood sizes resulted in nestlings that were lighter, in poorer body condition, had shorter head-bills, shorter and slower growing ninth primary feathers and that were less likely to survive to fledge. Next, I asked whether results obtained from long-term mark-recapture data corroborated findings of short-term manipulations. I examined seasonal variation in first-year apparent survival to investigate the relative influence of large-, small- and individual-scale factors associated with the quality and date hypotheses. Although parental quality was an important predictor of first-year apparent survival of tree swallows, my results further suggested that quality of parents was not the primary factor influencing seasonal variation in first-year apparent survival. Rather, findings were most consistent with the date hypothesis. The relationship between apparent survival and a direct measurement of environmental quality indicated that annual variation in moisture had important consequences for first-year apparent survival of tree swallows in Saskatchewan. First-year apparent survival probabilities were higher during wet years and wetter conditions are generally linked to greater insect abundance. In British Columbia, nestlings from larger broods were less likely to survive, possibly as a result of receiving less food. Apparent survival probabilities were also higher when food was more abundant. I demonstrated that both parental and environmental quality influenced seasonal variation in fitness-related traits of tree swallows. However, the strongest evidence suggests that environmental quality, and in particular food abundance, had the greatest effect on seasonal variation in nestling quality, reproductive success and first-year apparent survival in tree swallows. My results highlight the importance of considering regional precipitation trends when projecting effects of climate change on demography of aerial insectivores.

Abstract In conservation biology, informed and sound management decisions depend on target specific information about the life history and demography of the endangered populations. I used long-term, individual-based life history data (breeding and capture-recapture data) to examine life-history and demography in order to assess population viability and management. My study systems consist of metapopulations of two endangered, long-distance migratory wader species breeding on Baltic coastal meadows, the Temminck’s stint (Calidris temminckii) and the Southern Dunlin (Calidris alpina schinzii), whose breeding habitats are mainly managed by livestock grazing. Demographic models indicated that both study populations were sinks, which persist through immigration due to low local recruitment insufficient to compensate for adult mortality or emigration. Philopatric Temminck’s stints had higher nest and apparent adult survival compared to immigrants. Consideration of dispersal status in population models resulted in the most realistic estimates of population growth and revealed a low demographic impact of immigrants. Immigrants had low return rates after reproductive failure, suggesting that the difference in apparent survival was partly caused by different breeding dispersal strategies. Thus, management actions improving reproduction, and thus site fidelity, should also influence viability. An artificial nest experiment indicated high trampling rates under recommended stocking rates on managed meadows. This was attributed to similar space use of nesting Dunlin and cattle. Cattle presence did not affect nest predation. Young Dunlin preferred intensively grazed low sward habitat over high sward habitat. Reproductive success was also higher in low sward habitat. However, nests in the preferred habitat had the highest risk of being trampled if not artificially protected. Thus, low sward habitat was found to work as an ecological trap if grazing was started too early in the breeding season. Due to the sink nature of the Dunlin population even small reductions in reproductive success caused by trampling were detrimental to long term viability. The results encourage continuation of the use of cattle grazing as a management tool, but also highlight the need for more detailed consideration of local grazing practices, especially when sketching management plans for endangered species. / Tiivistelmä Uhanalaisten lajien suojelussa tehokkaiden suojelutoimien suunnittelu edellyttää tietoa hoitokohteen elinkierron eri vaiheista ja niiden demografisesta merkityksestä. Käytän tutkimuksessani pitkäaikaisaineistoja (pesintä ja merkintä-takaisinpyynti) kuvatakseni tutkimuslajien demografiaa ja arvioidessani populaatioiden elinkykyä sekä hoitotoimia. Tutkimuskohteinani ovat lapinsirrin ja etelänsuosirrin, kahden uhanalaisen kahlaajan, Perämeren rantaniityillä pesivät metapopulaatiot. Näiden lajien elinympäristöjä hoidetaan pääosin laiduntamalla. Demografinen mallinnus osoitti molempien populaatioiden olevan nielupopulaatioita, joiden säilyminen on tulomuuton varassa sillä poikastuotto ei kompensoi aikuisten kuolleisuutta ja poismuuttoa. Tutkimusalueella syntyneiden ja sinne rekrytoituneiden lapinsirrien pesä- ja aikuissäilyvyydet olivat paremmat kuin tulomuuttajilla. Tämän huomioiminen populaatiomalleissa tuotti realistisimman kasvukertoimen arvion ja osoitti paikallisten rekryyttien olevan tulomuuttajia merkittävämpiä populaation kasvun kannalta. Pesinnässään onnistuneet tulomuuttajat palasivat seuraavina pesimäkausina epäonnistuneita todennäköisemmin. Paikallisilla rekryyteillä vastaavaa eroa ei havaittu. Ilmiö heijastellee tulomuuttajien muuttoalttiutta myöhemminkin ja voi kertoa erilaisista pesimädispersaalistrategioista. Lisääntymismenestyksen parantaminen voisi parantaa elinkykyä myös pienentämällä poismuuttoa. Tekopesäkokeen perusteella pesien tallausriski oli laidunnetuissa ympäristöissä korkea vaikka laidunnuspaine noudatteli hoitosuosituksia. Tämä johtunee ainakin osin laskennallista korkeammasta todellisesta laidunpaineesta, mikä puolestaan johtui lintujen ja karjan yhtäläisestä tilankäytöstä. Rekrytoituvat suosirrit suosivat voimakkaasti laidunnettuja matalakasvuisia niittyjä, joissa poikastuotto oli parempi kuin, laiduntamattomilla niityillä. Toisaalta, tallausriski on voimakkaasti laidunnetuilla niityillä suuri ja jo pienetkin pesätappiot uhkaavat suosirripopulaation elinkykyä. Täten laitumet voivat toimia ns. ekologisina loukkuina, jos laidunnus aloitetaan liian aikaisin suhteessa pesintään. Laidunnus on kuitenkin suositeltava hoitomuoto, sillä se näyttää tuottavan parhaita pesimäympäristöjä etelänsuosirrille. Tulosten mukaan laidunnuksen ajoitusta, laajuutta ja laidunnuspainetta on muokattava kohdekohtaisesti, jotta saavutetaan paras tulos uhanalaisten lajien suojelun kannalta.