The ability to understand the complex mechanisms by which species communicate has been the focus of study for many years. The Adélie penguin (Pygoscelis adeliae) breeds in vocally challenging Antarctic colonies and has evolved a complex system of intra- and intersexual visual and vocal behaviours. Unique to the Adélie penguin, is the presence of two distinct display calls, the Loud Mutual Display (LMD) call and male Ecstatic Display Call (EDC). The EDC is used for both mate choice and territory defence; but apart from general structure and function this call remains basically unstudied. Therefore, the aim of this study is to examine the EDC with regard to its function (during mate choice) and variability over time, with location and with changing conditions. It is predicted that the EDC will be an individual call that is distinct from the LMD call. Additionally, the effects of an inclement breeding season on factors that affect breeding success will be examined using a logistic regression approach. The study took place over two breeding seasons(2000/1 & 2002/3) on Ross Island, Antarctica, with the majority of research being conducted at Cape Bird. Results of the study indicate that the EDC is an individual call that cannot reliably be described as a male display as females also give an EDC that is acoustically comparable. The similarities between the EDC and the LMD call seem to relate only to syllabic organisation (structure), as almost every call parameter was different between call types. Furthermore, several call parameters differed between Ross Island colonies. These parameters varied with both geographical location and colony size. In conjunction with variation in call parameters, the health and breeding success of the colonies was different. The stability of call parameters (from Cape Bird) indicated that parameters that separate colonies not only alter between breeding years, but also vary during a single breeding season. The function of the EDC as an honest signal during mate choice was supported by spectral analyses. These analyses found heavier males had significantly lower Frequency Modulation (FM) in the short repeated syllables of their calls than lighter males. Furthermore, a male’s breeding success could be predicted during the early breeding season by the FM. Logistic regression models showed that early male arrival, weight and good nest quality were most influential in predicting fledging success. The logistic regression method also showed that the parameters measured varied in their predictive ability as the season progressed. This study has not only enhanced the wealth of knowledge regarding Adélie breeding behaviour and developed our understanding of the vocal repertoire of this species, but also has implications for honest signalling theory, and the evolution and stability of vocal variation at different spatial and temporal scales.

The ability to understand the complex mechanisms by which species communicate has been the focus of study for many years. The Adélie penguin (Pygoscelis adeliae) breeds in vocally challenging Antarctic colonies and has evolved a complex system of intra- and intersexual visual and vocal behaviours. Unique to the Adélie penguin, is the presence of two distinct display calls, the Loud Mutual Display (LMD) call and male Ecstatic Display Call (EDC). The EDC is used for both mate choice and territory defence; but apart from general structure and function this call remains basically unstudied. Therefore, the aim of this study is to examine the EDC with regard to its function (during mate choice) and variability over time, with location and with changing conditions. It is predicted that the EDC will be an individual call that is distinct from the LMD call. Additionally, the effects of an inclement breeding season on factors that affect breeding success will be examined using a logistic regression approach. The study took place over two breeding seasons(2000/1 & 2002/3) on Ross Island, Antarctica, with the majority of research being conducted at Cape Bird. Results of the study indicate that the EDC is an individual call that cannot reliably be described as a male display as females also give an EDC that is acoustically comparable. The similarities between the EDC and the LMD call seem to relate only to syllabic organisation (structure), as almost every call parameter was different between call types. Furthermore, several call parameters differed between Ross Island colonies. These parameters varied with both geographical location and colony size. In conjunction with variation in call parameters, the health and breeding success of the colonies was different. The stability of call parameters (from Cape Bird) indicated that parameters that separate colonies not only alter between breeding years, but also vary during a single breeding season. The function of the EDC as an honest signal during mate choice was supported by spectral analyses. These analyses found heavier males had significantly lower Frequency Modulation (FM) in the short repeated syllables of their calls than lighter males. Furthermore, a male’s breeding success could be predicted during the early breeding season by the FM. Logistic regression models showed that early male arrival, weight and good nest quality were most influential in predicting fledging success. The logistic regression method also showed that the parameters measured varied in their predictive ability as the season progressed. This study has not only enhanced the wealth of knowledge regarding Adélie breeding behaviour and developed our understanding of the vocal repertoire of this species, but also has implications for honest signalling theory, and the evolution and stability of vocal variation at different spatial and temporal scales.

The ability to understand the complex mechanisms by which species communicate has been the focus of study for many years. The Adélie penguin (Pygoscelis adeliae) breeds in vocally challenging Antarctic colonies and has evolved a complex system of intra- and intersexual visual and vocal behaviours. Unique to the Adélie penguin, is the presence of two distinct display calls, the Loud Mutual Display (LMD) call and male Ecstatic Display Call (EDC). The EDC is used for both mate choice and territory defence; but apart from general structure and function this call remains basically unstudied. Therefore, the aim of this study is to examine the EDC with regard to its function (during mate choice) and variability over time, with location and with changing conditions. It is predicted that the EDC will be an individual call that is distinct from the LMD call. Additionally, the effects of an inclement breeding season on factors that affect breeding success will be examined using a logistic regression approach. The study took place over two breeding seasons(2000/1 & 2002/3) on Ross Island, Antarctica, with the majority of research being conducted at Cape Bird. Results of the study indicate that the EDC is an individual call that cannot reliably be described as a male display as females also give an EDC that is acoustically comparable. The similarities between the EDC and the LMD call seem to relate only to syllabic organisation (structure), as almost every call parameter was different between call types. Furthermore, several call parameters differed between Ross Island colonies. These parameters varied with both geographical location and colony size. In conjunction with variation in call parameters, the health and breeding success of the colonies was different. The stability of call parameters (from Cape Bird) indicated that parameters that separate colonies not only alter between breeding years, but also vary during a single breeding season. The function of the EDC as an honest signal during mate choice was supported by spectral analyses. These analyses found heavier males had significantly lower Frequency Modulation (FM) in the short repeated syllables of their calls than lighter males. Furthermore, a male’s breeding success could be predicted during the early breeding season by the FM. Logistic regression models showed that early male arrival, weight and good nest quality were most influential in predicting fledging success. The logistic regression method also showed that the parameters measured varied in their predictive ability as the season progressed. This study has not only enhanced the wealth of knowledge regarding Adélie breeding behaviour and developed our understanding of the vocal repertoire of this species, but also has implications for honest signalling theory, and the evolution and stability of vocal variation at different spatial and temporal scales.

Birds face many challenges from the process of urbanisation. Those species that are able to occupy urban areas offer opportunities to understand processes of acclimatisation to urban life and may help in the development of urban spaces for the benefit of wildlife. In many bird species, individuals that occupy territories in more urban areas show lower productivity and lower body condition of nestlings, which is thought to be mediated by food availability. Most of the studies exploring this issue were done on passerines and carried out in the global north, with very few studies exploring this topic on non-passerines, and even fewer in Africa. Studies addressing urban productivity in apex predators with slow life histories that are often of conservation concern are largely missing. Here, we explore the breeding performance of the African Crowned Eagles (Stephanoaetus coronatus) across an urbanisation gradient in KwaZuluNatal, South Africa. Specifically, we explored the hypothesis that living in an urban environment allows this species, which is typically a biennial breeder, to breed annually more often (i.e. increased breeding rate), and whether this might increase the productivity of this species. We also explore whether there may be any hidden costs of such a breeding strategy by examining the condition of chicks for pairs which had successfully bred in the previous year. We found that Crowned Eagles breeding in more urban areas attempted to breed more often (i.e., higher breeding rate), but that these birds also suffered from lower breeding success. These two contrasting responses counteracted each other and meant that overall productivity (number of young produced per occupied territory) was not influenced by urbanisation. Breeding annually did not appear to have a negative cost on the chick condition, as offspring in the year following a successful breeding attempt did not have lowered body condition. This species appears to be well adjusted to breeding in an urban environment. Crowned Eagles are currently considered vulnerable in South Africa, and ensuring that an urban population of this species is able to persist can help secure the conservation status of this charismatic species.

付記する学位プログラム名: 霊長類学・ワイルドライフサイエンス・リーディング大学院 / 京都大学 / 新制・課程博士 / 博士(理学) / 甲第25153号 / 理博第5060号 / 京都大学大学院理学研究科生物科学専攻 / (主査)教授 村山 美穂, 教授 平田 聡, 教授 三谷 曜子 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DGAM

<p>Abstrakt: Jag har undersökt hur älvreglering påverkar mängden knott (Tvåvingar: <i>Simuliidae</i>) längs flera norrlandsälvar och vilka konsekvenser denna påverkan får för den landlevande fågelfaunan. Studien visar att utbyggnad av älvar har en negativ effekt på mängden knott. Det fanns sju gånger högre tätheter av knott längs "orörda älvar" jämfört med utbyggda älvar.</p><p>Skillnaden i antal knott mellan älvtyperna var mycket större för knotthanar än för knotthonor, vilket förklaras av att honorna är rörligare eftersom de flyger och letar efter blod. Knott lever av blod från ett flertal däggdjur och fåglar och visar en stor variation i värd-specificitet mellan olika arter. Jag fann en högre frekvens av haemosporida blod parasiter (<i>Leucocytozoon</i>) i fåglar längs "orörda" Vindelälven jämfört med den reglerade Umeälven. Detta mönster stämmer väl överens med tätheten fågelparasiterande knott som är lägre längs Umeälven. Knott attackerade främst värdar som var stora och vanliga. Fågelsamhällets sammansättning skiljde sig mellan orörda och utbyggda älvdalar. Tätheten av icke insektsätande fåglar tenderade att minska, efter häcksäsongen, längs orörda älvar medan den ökade längs utbyggda älvar. Den insektsätande fågeln svartvit flugsnappare (<i>Ficedula hypoleuca Pallas</i>) uppvisade större häckningsframgång längs orörda älvar jämfört med utbyggda älvar. Detta är förmodligen en effekt av den större mängden insekter som finns längs orörda älvar.</p> / <p>The effects of river regulation on blackfly (Diptera: <i>Simuliidae</i>) abundances and consequences for the avifauna in terrestrial environments were studied along multiple rivers in northern Sweden. I found that impoundment of rivers has detrimental effect to blackfly abundances. The densities of large-river breeding blackfly species were several-fold higher along free-flowing than along regulated rivers. The difference in abundances was much larger in males than blood-seeking females. Blackflies attacked a variety of mammalian and avian hosts and showed different levels of host-specificity between species. I found higher prevalence of haemosporidian blood parasites (<i>Leucocytozoon</i>) in birds along the free-flowing Vindel River in comparison to the regulated Ume River, where the lower densities of ornithophilic blackflies were reduced. Blood-seeking blackflies predominantly attacked large and/abundant hosts.</p><p>Assemblages of birds differed between valleys of regulated and free-flowing rivers. Densities of noninsectivorous birds tended to decrease along free-flowing rivers in the post-breeding season, but increased along regulated rivers at the same time. Insectivorous European pied flycatcher (<i>Ficedula hypoleuca Pallas</i>) showed greater fledging success along free-flowing than regulated rivers, which probably reflects the higher insect abundances found along freeflowing rivers.</p>

Abstrakt: Jag har undersökt hur älvreglering påverkar mängden knott (Tvåvingar: Simuliidae) längs flera norrlandsälvar och vilka konsekvenser denna påverkan får för den landlevande fågelfaunan. Studien visar att utbyggnad av älvar har en negativ effekt på mängden knott. Det fanns sju gånger högre tätheter av knott längs "orörda älvar" jämfört med utbyggda älvar. Skillnaden i antal knott mellan älvtyperna var mycket större för knotthanar än för knotthonor, vilket förklaras av att honorna är rörligare eftersom de flyger och letar efter blod. Knott lever av blod från ett flertal däggdjur och fåglar och visar en stor variation i värd-specificitet mellan olika arter. Jag fann en högre frekvens av haemosporida blod parasiter (Leucocytozoon) i fåglar längs "orörda" Vindelälven jämfört med den reglerade Umeälven. Detta mönster stämmer väl överens med tätheten fågelparasiterande knott som är lägre längs Umeälven. Knott attackerade främst värdar som var stora och vanliga. Fågelsamhällets sammansättning skiljde sig mellan orörda och utbyggda älvdalar. Tätheten av icke insektsätande fåglar tenderade att minska, efter häcksäsongen, längs orörda älvar medan den ökade längs utbyggda älvar. Den insektsätande fågeln svartvit flugsnappare (Ficedula hypoleuca Pallas) uppvisade större häckningsframgång längs orörda älvar jämfört med utbyggda älvar. Detta är förmodligen en effekt av den större mängden insekter som finns längs orörda älvar. / The effects of river regulation on blackfly (Diptera: Simuliidae) abundances and consequences for the avifauna in terrestrial environments were studied along multiple rivers in northern Sweden. I found that impoundment of rivers has detrimental effect to blackfly abundances. The densities of large-river breeding blackfly species were several-fold higher along free-flowing than along regulated rivers. The difference in abundances was much larger in males than blood-seeking females. Blackflies attacked a variety of mammalian and avian hosts and showed different levels of host-specificity between species. I found higher prevalence of haemosporidian blood parasites (Leucocytozoon) in birds along the free-flowing Vindel River in comparison to the regulated Ume River, where the lower densities of ornithophilic blackflies were reduced. Blood-seeking blackflies predominantly attacked large and/abundant hosts. Assemblages of birds differed between valleys of regulated and free-flowing rivers. Densities of noninsectivorous birds tended to decrease along free-flowing rivers in the post-breeding season, but increased along regulated rivers at the same time. Insectivorous European pied flycatcher (Ficedula hypoleuca Pallas) showed greater fledging success along free-flowing than regulated rivers, which probably reflects the higher insect abundances found along freeflowing rivers.

Šis darbas yra skirtas banguotųjų papūgėlių veisimosi sistemos, kintant lyčių santykiui grupėje, tyrimams. Tyrimų rezultatai rodo, kad vyraujanti veisimosi sistema banguotųjų papūgėlių grupėje su vienodu lyčių santykiu, grupėje esant patinų trūkumui ir grupėje, kurioje trūksta patelių, yra monogamija. Poligamijos atveju, poliginiški patinai vieną savo patelių – dominantę - maitina geriau negu kitą, nedominuojančią patelę. Kopuliacijos su ne savo poros nariu yra retos. Patelės kopuliuoja su tais patinais, kurie geriausiai jas maitina. Ištirta, kad dominuojančios patelės veisiasi geriau negu nedominuojančios. Agonistinė šios rūšies paukščių elgsena jų veisimosi sistemos tiesiogiai neįtakoja. Monogamija yra vyraujantis banguotųjų papūgėlių veisimosi būdas, kadangi patinų tėviška globa yra labai svarbus veiksnys, įtakojantis patelių veisimosi sėkmę. / The aim of the study was to investigate the influence of sex ratio on the reproductive system of the budgerigars. The main reproductive system in all the groups was monogamy, i.e. in the group of birds with the equal sex ratio, in the group with female-biased sex ratio and in the group with male-biased sex ratio. The polygynous males fed their primary females more often in comparison with secondary females. Extra-pair copulations were rare. The females copulated with those males which fed them the best in the group of polygamous birds. The reproductive success of primary females was higher in comparison to secondary females. The agonistic behaviour was not an immediate factor of the main reproductive system in budgerigars. Monogamy seems to be the optimum mating situation for female of this species, because the paternal investment of the male turns out to be very important to female’s breeding success.

Darbo metu buvo nustatyti baltojo gandro gausumo ir erdvinio pasiskirstymo bei lizdaviečių pasirinkimo pokyčiai 1994–2010 metais, ištirti perėjimo buveinės pasirinkimo dėsningumai bei perėjimo sėkmingumo priklausomybė nuo kai kurių buveinės charakteristikų. Baltojo gandro perėjimo buveinės pasirinkimo tyrimai atlikti su 8,4 % pasaulinės perinčios baltojo gandro populiacijos, esančios arealo šiaurės vakarų periferijoje, susitelkusios teritorijoje, užimančioje 1,1 % arealo ploto. Buvo nustatyta, kad tyrimų teritorijoje per 1994–2010 metų laikotarpį ženkliai išaugus baltojo gandro gausumui, paukščiai prisitaikė perėti naujo tipo lizdavietėse – ant elektros oro linijų atramų. Šis prisitaikymas reprodukciniu požiūriu buvo iš dalies neadaptyvus dėl patikimai mažesnio perėjimo sėkmingumo lizduose, susuktuose ant eksploatuojamų elektros oro linijų atramų. Remiantis ilgalaikiais baltojo gandro pirmo atskridimo datos duomenimis, rinktais 1961–2000 metais, buvo nustatytas reikšmingas pavasarinio atskridimo datos į perimvietes arealo šiaurės vakarų periferijoje paankstėjimas. Taip pat buvo nustatyti veiksniai, lemiantys pirmo pavasarinio atskridimo į perimvietes datą. Darbe buvo nustatyti pagrindiniai, perinčiam baltajam gandrui grėsmę keliantys veiksniai, įvertintas jų reikšmingumas ir pasiūlytos neigiamo jų poveikio šiai Europos Sąjungoje saugomai rūšiai sumažinimo priemonės. / In this study, changes during the period 1994–2010 in White Stork abundance and spatial distribution, as well as in nest-site selection were determined; regularities in breeding habitat selection and the effect of some habitat characteristics on the breeding success were investigated. The White Stork habitat selection study was carried out in the north-western periphery of the species’ range on a sample, comprising 8.4% of the total breeding population of this species, concentrated in an area covering just 1.1% of its range. It was revealed that a considerable increase in the White Stork abundance in 1994–2010 coincided with the adaptation by birds to breeding at a new nest-site – on poles of overhead electricity lines. However, from the standpoint of reproduction, this change in the White Stork nesting behaviour was partly non-adaptive due to significantly lower breeding success in nests built on poles of operating overhead electricity lines. Data on the White Stork first spring arrival, collected during the period 1961–2000, revealed a significant advancement of spring arrival date to the breeding grounds in the north-western periphery of the range. Factors, affecting the first spring arrival to breeding grounds, were determined. The main threats facing the breeding White Storks were determined, their importance was assessed, and recommendations for the mitigation of these negative impacts were prepared for this species of the EU conservation concern.

In this study, changes during the period 1994–2010 in White Stork abundance and spatial distribution, as well as in nest-site selection were determined; regularities in breeding habitat selection and the effect of some habitat characteristics on the breeding success were investigated. The White Stork habitat selection study was carried out in the north-western periphery of the species’ range on a sample, comprising 8.4% of the total breeding population of this species, concentrated in an area covering just 1.1% of its range. It was revealed that a considerable increase in the White Stork abundance in 1994–2010 coincided with the adaptation by birds to breeding at a new nest-site – on poles of overhead electricity lines. However, from the standpoint of reproduction, this change in the White Stork nesting behaviour was partly non-adaptive due to significantly lower breeding success in nests built on poles of operating overhead electricity lines. Data on the White Stork first spring arrival, collected during the period 1961–2000, revealed a significant advancement of spring arrival date to the breeding grounds in the north-western periphery of the range. Factors, affecting the first spring arrival to breeding grounds, were determined. The main threats facing the breeding White Storks were determined, their importance was assessed, and recommendations for the mitigation of these negative impacts were prepared for this species of the EU conservation concern. / Darbo metu buvo nustatyti baltojo gandro gausumo ir erdvinio pasiskirstymo bei lizdaviečių pasirinkimo pokyčiai 1994–2010 metais, ištirti perėjimo buveinės pasirinkimo dėsningumai bei perėjimo sėkmingumo priklausomybė nuo kai kurių buveinės charakteristikų. Baltojo gandro perėjimo buveinės pasirinkimo tyrimai atlikti su 8,4 % pasaulinės perinčios baltojo gandro populiacijos, esančios arealo šiaurės vakarų periferijoje, susitelkusios teritorijoje, užimančioje 1,1 % arealo ploto. Buvo nustatyta, kad tyrimų teritorijoje per 1994–2010 metų laikotarpį ženkliai išaugus baltojo gandro gausumui, paukščiai prisitaikė perėti naujo tipo lizdavietėse – ant elektros oro linijų atramų. Šis prisitaikymas reprodukciniu požiūriu buvo iš dalies neadaptyvus dėl patikimai mažesnio perėjimo sėkmingumo lizduose, susuktuose ant eksploatuojamų elektros oro linijų atramų. Remiantis ilgalaikiais baltojo gandro pirmo atskridimo datos duomenimis, rinktais 1961–2000 metais, buvo nustatytas reikšmingas pavasarinio atskridimo datos į perimvietes arealo šiaurės vakarų periferijoje paankstėjimas. Taip pat buvo nustatyti veiksniai, lemiantys pirmo pavasarinio atskridimo į perimvietes datą. Darbe buvo nustatyti pagrindiniai, perinčiam baltajam gandrui grėsmę keliantys veiksniai, įvertintas jų reikšmingumas ir pasiūlytos neigiamo jų poveikio šiai Europos Sąjungoje saugomai rūšiai sumažinimo priemonės.