Noise pollution can mask or distort bird songs, which inhibits mating success, predator detection, and parental response to begging calls. Road noise can cause lowered density and reproductive success in songbirds. I examined the impact of construction noise on reproductive success and territory selection of golden-cheeked warblers (Dendroica chrysoparia) at 3 sites: adjacent to road construction, adjacent to road-noise only, and a control with no noise or construction activity. I also examined birds' responses to experimental playback of construction noise to determine if warblers alter behavior in the presence of introduced road construction noise, if they have habituated to construction noise, and whether habituation is hindering their reproductive success. I used the Vickery reproductive index to evaluate productivity and automatic recording units to assess the levels of ambient noise in each site. From 2007-2009, productivity was stable in the road-noise only site and showed more annual variation in the construction and control sites; productivity was nearly identical in the latter 2 sites in 2008 and 2009. There was no significant difference in productive territory locations based on distance from road. Ambient noise was similar in the construction and roadnoise only sites but significantly different from the control. To examine habituation and territory placement, I (1) used construction noise playback to individual birds and evaluated occurrence of behavioral response as a function of distance from the roadway, and (2) established broadcast stations that simulate construction noise to determine impacts on territory selection. Of 88 surveys, 6 birds responded to construction noise playback. I conducted 18 control surveys and observed 1 behavioral response. All birds that responded were located greater than or equal to 140 m from the road. I established 3 broadcast stations per season in 2008 and 2009. In each year I placed broadcast units on the edges of randomly chosen territories identified during the previous field season. There was not a significant difference in mean territory shifts for broadcast and non-broadcast unit territories, and territory shifts did not show patterns in directionality or in reproductive success. Results suggest that construction noise does not appear to affect behavior or reproductive success of golden-cheeked warblers.

Although nest reuse is most commonly associated with costs such as nest instability and increased ectoparasite loads,contrary evidence supports the possibility that nest reuse might provide an adaptive function in the form of time and energy savings. The Cave Swallow (Petrochelidon fulva), which nests under bridges and culverts in east-central Texas, chooses predominately to reuse nests when old nests are available. I conducted a field experiment involving bridge pairs and single bridges, in which I applied a treatment of nest removal to one bridge of each pair and one half of each single bridge in order to test whether control bridges and nests exhibited increased productivity from the availability of old nests. I found that a higher percentage of young fledged from control bridges and more fledged per clutch from control bridges. Small sample sizes diminished the ability to detect differences within the single bridge experiment. Results from this research support the time-energy savings concept and may be reconciled with conflicting research through fundamental differences between studies in immunity to ectoparasites, infestation type, and nest microclimate.

Understanding how environmental variation affects fitness and population dynamics is a central goal in modern population biology. Using a multilevel path model, I simultaneously examined the effects of food and temperature on multiple stages of the breeding cycle, and their relative contribution to annual variation in reproductive success in two tree swallow (Tachycineta bicolor) populations over the same 35 year period. In one population where food abundance peaked during the laying and incubation portion of the breeding season, the primary driver of annual reproductive success was laying period food abundance, which directly influenced clutch size and the proportion of eggs hatched. In the second population, food was relatively low during the first half of the breeding season, and the primary driver of annual reproductive success was temperature during the nestling period, which directly influenced nestling survival. My results show that understanding the factors that influence reproductive performance requires linking environmental variables to reproductive events throughout the entire breeding period and clearly demonstrate how climate change can have opposite effects on two populations less than 35 km apart

Many species have suffered severe range contractions as a result of human impacts, and require careful management if they are to persist. An understanding of the ecology, population structure and mating system is important for the conservation of these endangered species. Translocation has become a widely used tool in the conservation of threatened species; however, without proper planning and monitoring, many programmes end in failure. The bridled nailtail wallaby is one of the most endangered macropods in Australia, having suffered an extensive range contraction from the semi-arid region of eastern Australia to a single remnant population of ~ 500 animals at Taunton National Park in Queensland. In 1996, a translocated population of bridled nailtail wallabies was established at Idalia National Park, on the western edge of the former range of this species. The aims of this study were to: 1) determine the factors underlying variation in reproductive success among animals released at Idalia; 2) investigate the effects of a range decline on the genetic variation and population structure of the remnant population at Taunton; 3) assess the impact of captive breeding and translocation on the genetic diversity and structure of the established population at Idalia; and 4) investigate male and female mating strategies in this species. Chapter two investigated reproductive success among males released at Idalia National Park. The bridled nailtail wallaby is a sexually dimorphic, polygynous species and there is a large amount of variation in male reproductive success. Animals of different origin were released, including animals bred in captivity off the park, animals bred on-site in enclosures, and wild-caught animals from the remnant population that were moved directly to Idalia. There was significant variation in reproductive success among males released, but the origin of those animals did not explain this variation. Instead, large males were the most reproductively successful regardless of origin. Survival probability and release location were also important factors. This study highlighted the importance of considering mating system when choosing animals for translocation and suggests that, for polygynous species, a greater proportion of females and males of high breeding potential should be released. In Chapter three I investigated the genetic diversity and fine-scale genetic structure of the remnant population at Taunton. This last remaining population has been isolated for at least 60 years, corresponding to 30 generations for this species. Animals are patchily distributed in assemblages of different size that cover ~ 10% of suitable habitat on the park. Genetic diversity was surprisingly high within the population remnant and this species showed one of the highest levels of heterozygosity and allelic diversity of any macropod. The three sub-populations of animals sampled over 10 km were significantly differentiated, and fine-scale spatial genetic structure was also observed within a continuous sub-population of animals covering just 750 ha. Females were more related to each other than expected from random, whereas males were less related to each other than expected. Fine-scale genetic structure was observed among females but not males, providing evidence for female philopatry and male-biased dispersal. I suggest that fine-scale population structure and restricted gene flow among females but not males may maintain genetic diversity in this remnant population. Chapter four assessed the effect of translocation of animals of different origin on genetic diversity in bridled nailtail wallabies. Both wild-caught and captive-bred animals were initially released, but subsequent releases consisted of captive-bred animals only. In this study, I compared genetic diversity of released animals to animals sampled in the remnant population. Heterozygosity did not differ between the remnant and translocated population, however allelic diversity was significantly reduced among all groups released. Animals bred in captivity were significantly differentiated from the source population, whereas animals moved directly from Taunton were not. Releasing more captive-bred animals into the population after the initial release resulted in a decline in overall heterozygosity and allelic diversity. This study highlights the importance of sourcing animals directly from remnant populations in order to maintain genetic diversity and minimize genetic drift between source and recipient populations. The bridled nailtail wallaby has a polygynous mating system and reproductive success is skewed toward large males. However unlike most polygynous, sexually dimorphic macropods, the bridled nailtail wallaby is highly solitary; animals only associate to breed and males do not form stable dominance hierarchies. In Chapter five I investigated behavioural strategies used by males to secure matings, and mate choice among females. I found that males of different size adopted different mating strategies. Large males spent more time guarding females against other males and maintaining contact with them, whereas smaller males spent less time with guarded females in order to search for other females in oestrus. Females also preferred larger males and were more likely to engage in mate chases if there was a large number of males within the group.

Master of Science / Department of Biology / Brett K. Sandercock / Translocations are a useful management tool for restoring wildlife species to their native ranges, but require post-release monitoring to determine project success. We report results of a 4-year effort to reestablish a breeding population of Evermann's Rock Ptarmigan (Lagopus mutus evermanni) on Agattu Island in the Aleutian Archipelago, Alaska. This endemic subspecies of ptarmigan was extirpated from most of the Near Islands by introductions of arctic fox by fur traders, and natural recolonizations did not occur after fox eradication. All females surviving the 2-week post-release period attempted to nest but initiated clutches later in the season and laid fewer eggs than resident females. Nest success was similar for resident and translocated females. Brood survival was greater for translocated than resident females and differed significantly; however, brood survival varied among years and was reduced by adverse weather conditions in 2006. Seasonal survival of radio-marked birds during the breeding season was 100% for translocated and resident ptarmigan. Over-winter mortality resulted in a low return rate in 2006. Returning birds in 2006 showed strong site fidelity and nest locations in two consecutive years were closely spaced. We examined nest site selection and determined brood movements and home range size of recently translocated and resident females. Nest sites of translocated females averaged 4.2 km from their respective release location and were not different from nest locations of resident females with regard to topographical features. Female nest site selection was influenced by percent composition of rock and forb coverage but was unaffected by slope, aspect, or general habitat. Broods of both resident and translocated females made movements to higher elevations after hatching. While size of brood home range was similar for resident and translocated females, distances traveled between the nest site and the arithmetic center of the brood home range were greater for translocated females. Overall, we conclude that translocations are an effective technique for reestablishing island populations of Rock Ptarmigan. Our study provides successful methods which may benefit future projects to reestablish endemic populations of ptarmigan and landbirds elsewhere in the Aleutian Islands.

京都大学 / 0048 / 新制・課程博士 / 博士(人間・環境学) / 甲第21875号 / 人博第904号 / 新制||人||215(附属図書館) / 2018||人博||904(吉田南総合図書館) / 京都大学大学院人間・環境学研究科相関環境学専攻 / (主査)教授 瀬戸口 浩彰, 教授 加藤 眞, 教授 市岡 孝朗, 准教授 西川 完途 / 学位規則第4条第1項該当 / Doctor of Human and Environmental Studies / Kyoto University / DGAM

No description available.

As environmental change continues and increases, understanding how species will respond to change and how these responses may affect populations will be important for conserving and managing species. Red-cockaded Woodpeckers (Picoides borealis) are well-studied and provide an ideal system in which to examine ecological and evolutionary questions related to life histories because monitoring them accurately is relatively easy, their behavior is well-described and structured. In this study, I examined the following questions using long-term data (1980-2013) from two study sites in North Carolina: 1) what traits contribute most to lifetime fitness, 2) how have traits changed over time and how is climate change influencing life history, and 3) to what extent are traits that contribute to fitness and that are changing over time heritable in this species. I found that a multitude of factors contribute to different aspects of fitness, including: parental age and hatch date affecting survival to year one and probability of attaining breeding status; and lay date, clutch size, age at first reproduction, and variance in clutch size affecting lifetime fitness. I also found that many traits were changing over time including lay date, clutch size, partial brood loss, and survival to year one. These traits were strongly influenced by local climate variables at each study site, but it is not clear that climate has changed over time at the study sites to account for all the observed changes in life history traits. Habitat improvement has also played a role as evidenced by increased fledgling production in terms of raw numbers (without accounting for covariates). I also found that lay date, clutch size, and partial brood loss had low heritabilities after accounting for other random and fixed effects. These results indicate that Red-cockaded Woodpeckers at these two study sites are shifting traits successfully in response to changing conditions, and that these changes are in the direction that increases aspects of fitness. These shifts indicate that individuals are plastic with respect to these traits, but most of the variance in traits was related to external habitat-associated factors rather than additive genetic variance or environmental × genotype interactions. / Ph. D.

Aquatic biodiversity continues to decline as humans modify the landscape. A population-level approach is necessary to address the mechanisms of impairment in urban stream habitats. When estimating population-level parameters, incomplete detection of individuals must be accounted for to ensure unbiased estimates. In this thesis, I examined differences in the detection probabilities of stream fishes, and used estimates of size/age-specific detection probabilities to reduce bias in estimates of the reproductive success of various fish species in urban and forested stream habitats. In Chapter 1, I examined differences in detection probabilities of stream fishes among electrofishing passes and size/age groups in the middle New River basin, Virginia. I also examined differences in detection probabilities between two physiographic regions: the middle New River basin, and the upper Wabash River basin, Indiana; and evaluated differences between single- and multiple-season estimation methods. I found that for most species, detection probabilities do not differ among electrofishing passes, size/age classes, between the two regions, or between single- and multiple-season estimation methods. I used size/age-specific estimates of detection probabilities to remove bias from relative abundance estimates of steam fish populations in Chapter 2. In Chapter 2, I examined the reproductive success of six lithophilic and speleophilic fishes in urban and forested reaches of 2nd-4th Strahler-order streams in the middle New River basin. I found that binary classification is a poor method of quantifying reproductive success, that the age distributions of many lithophilic and speleophilic species are dominated by adult individuals in urban habitats, and that the population growth rates of speleophils is reduced in urban habitats. These results suggest that although detection probabilities may be equal among various sources of variation, managers should verify this assumption before assuming equal detectability. The results also suggest that reduced reproductive success of speleophilic and lithophilic species in urban stream habitats may be a mechanism of their impairment. / Master of Science

Selection operates when the variability among individuals in heritable traits translates to differences in the number of offspring that survive to breed, which is a close estimate of fitness. Consequently, the outcome of sexual-selection should be higher reproductive success for individuals with a greater expression of the selected traits. In this thesis, the relationship between some male spotless starling (Sturnus unicolor) traits and reproductive success was assessed. A particular focus was given to the role of throat feathers (TF) as sexually selected trait. The study was conducted in a wild population using a correlative approach in 2004, while in 2005 and 2006 the TF of males were experimentally shortened. The genetic parentage of the offspring was required for determining the reproductive success of males. Nine highly polymorphic microsatellites (with 11.7± 3.2 alleles per locus) were developed and optimised for this species. Parentage analyses were conducted in NEWPAT XL and CERVUS 3.0.3 and confirmed using observational data. Eighty-five percent of the offspring had at least one parent assigned. The levels of intra-specific brood parasitism, extra-pair paternity and quasi-parasitism were 7%, 7% and 1% of the offspring, respectively. Polygamy levels decreased with year, as the study population matured. The correlative study showed that males with longer TF and with better condition had a higher probability of reproducing and sired more offspring, but their offspring were not of higher quality as measured by their weight and immune response to phytohaemagglutinin. Polygynous males were also in better condition. In the experimental study, males in better condition had a higher chance of reproducing and sired more fledglings. Conversely, males with reduced TF sired significantly fewer eggs and lighter fledglings than control males. Body condition and TF length are shown to be good predictors of reproductive success and TF length is shown to be under sexual selection.