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T. Kurt Kyser

Bio: T. Kurt Kyser is an academic researcher from Queen's University. The author has contributed to research in topics: Population & Redstart. The author has an hindex of 29, co-authored 94 publications receiving 3312 citations. Previous affiliations of T. Kurt Kyser include Smithsonian Institution & Simon Fraser University.
Topics: Population, Redstart, Setophaga, Carbonate, Feather


Papers
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Journal ArticleDOI
TL;DR: It is shown that the reproductive success of a long‐distance migratory bird is influenced by the quality of habitat located thousands of kilometres away on tropical wintering grounds, which affected key variables associated with reproduction, including the number of young fledged.
Abstract: Identifying the factors that control population dynamics in migratory animals has been constrained by our inability to track individuals throughout the annual cycle. Using stable carbon isotopes, w...

659 citations

Journal ArticleDOI
TL;DR: The results suggest that changes in climatic conditions during the pre-breeding period may have severe consequences for reproductive success by influencing breeding date and egg size.
Abstract: 1. Understanding the interactions between different periods of the annual cycle in migratory animals has been constrained by our inability to track individuals across seasons. In seabirds, virtually nothing is known about how diet quality during the non-breeding period, away from the breeding grounds, might influence subsequent reproductive success. 2. We used stable nitrogen (delta(15)N) and carbon (delta(13)C) isotopes to evaluate the effects of non-breeding diet quality on the timing of breeding and egg size in a population of Cassin's auklets (Ptychoramphus aleuticus) breeding on Triangle Island, British Columbia. Adult feathers are grown during two different periods of the annual cycle, which allowed us to estimate diet quality from the previous fall (October-November) and pre-breeding (February-March) period. 3. We found that the estimated proportion of energetically superior copepods (Neocalanus spp.) in the pre-breeding diet tended to be higher in females that bred earlier and laid larger eggs, whereas energetically poor juvenile rockfish (Sebastes spp.) were dominant in the pre-breeding diets of females that bred later and laid smaller eggs. We detected no effect of fall diet quality on breeding date or egg size, and no effect of pre-breeding diet quality on breeding date in males. 4. Pre-breeding diet quality was not related to body condition measured 1-2 days after laying, which suggests that females may need to attain a threshold condition before they initiate breeding and successfully rear young. 5. Our results suggest that changes in climatic conditions during the pre-breeding period may have severe consequences for reproductive success by influencing breeding date and egg size. Our work emphasizes the importance of determining how events are linked throughout the annual cycle for understanding the fitness and population dynamics of migratory animals.

198 citations

Journal ArticleDOI
TL;DR: It is shown that the mixed-mating strategy of American redstart compounds the benefits of overwintering in high-quality winter habitats, resulting in a lower probability of paternity loss, a higher probability of achieving polygyny and ultimately higher realized reproductive success.
Abstract: The study of sexual selection has traditionally focused on events and behaviours immediately surrounding copulation. In this study, we examine whether carry-over effects from the non-breeding season can influence the process of sexual selection in a long-distance migratory bird, the American redstart (Setophaga ruticilla). Previous work on American redstarts demonstrated that overwintering in a highquality habitat influences spring departure dates from the wintering grounds, advances arrival dates on the breeding grounds and increases apparent reproductive success. We show that the mixed-mating strategy of American redstarts compounds the benefits of overwintering in high-quality winter habitats. Males arriving to breed in Canada from high-quality winter habitats arrive earlier than males from poor-quality habitats, resulting in a lower probability of paternity loss, a higher probability of achieving polygyny and ultimately higher realized reproductive success. Such results suggest that the process of sexual selection may be influenced by events interacting throughout the annual cycle.

154 citations

Journal ArticleDOI
24 Dec 2004-Science
TL;DR: It is shown how reproduction in a migratory animal can influence both life history strategies (location of molt) and social signals (feather color) during subsequent periods of the annual cycle.
Abstract: Toward the end of the breeding season, migratory songbirds face crucial tradeoffs between the timing of reproduction, molt, and migration. Using stable hydrogen isotopes, we show that male American redstarts investing in high levels of reproduction late in the season adopt a unique strategy of combining molt and migration. Tail feathers molted during migration also reflect less orange-red light, indicating reduced carotenoid concentration. Thus, we show how reproduction in a migratory animal can influence both life history strategies (location of molt) and social signals (feather color) during subsequent periods of the annual cycle.

139 citations

Journal ArticleDOI
TL;DR: It is concluded that feathers sampled from recently hatched juveniles may not provide a reliable estimate of expected local isotopic signatures for comparison with adult feathers of unknown origin, and it is suggested that the best approach is to assign individuals to broad geographic zones within a species’ potential molting range.
Abstract: Continent-wide variation in hydrogen isotopic composition of precipitation is incorporated into animal diets, providing an intrinsic marker of geographic location at the time of tissue growth. Feathers from migratory birds are now frequently analyzed for stable-hydrogen isotopes (δD) to estimate the location of individuals during a preceding molt. Using known-origin birds, we tested several assumptions associated with this emerging technique. We examined hydrogen isotopic variation as a function of age, sex, feather type and the timing of molt in a marked population of American redstarts (Setophaga ruticilla) breeding in southeastern Ontario. We measured δD in feathers and blood from individuals that bred or hatched at our study site during the year in which those tissues were grown. Juvenile tissues from 5- to 10-day-old birds had more negative δD values than those from adults, which most likely reflected age-related differences in diet. Within adults, primary feathers had more negative δD values than contour feathers. The mean δD value in adult primary feathers was relatively consistent among years and with the value expected for our study population. However, among-individual variation in δD corresponded to an estimated latitudinal range of 6–8° (650–900 km). We conclude that feathers sampled from recently hatched juveniles may not provide a reliable estimate of expected local isotopic signatures for comparison with adult feathers of unknown origin. Furthermore, we urge researchers to use caution when using δD values in feathers to infer geographic origin, and suggest that the best approach is to assign individuals to broad geographic zones within a species’ potential molting range.

127 citations


Cited by
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01 Jan 1980
TL;DR: In this article, the influence of diet on the distribution of nitrogen isotopes in animals was investigated by analyzing animals grown in the laboratory on diets of constant nitrogen isotopic composition and found that the variability of the relationship between the δ^(15)N values of animals and their diets is greater for different individuals raised on the same diet than for the same species raised on different diets.
Abstract: The influence of diet on the distribution of nitrogen isotopes in animals was investigated by analyzing animals grown in the laboratory on diets of constant nitrogen isotopic composition. The isotopic composition of the nitrogen in an animal reflects the nitrogen isotopic composition of its diet. The δ^(15)N values of the whole bodies of animals are usually more positive than those of their diets. Different individuals of a species raised on the same diet can have significantly different δ^(15)N values. The variability of the relationship between the δ^(15)N values of animals and their diets is greater for different species raised on the same diet than for the same species raised on different diets. Different tissues of mice are also enriched in ^(15)N relative to the diet, with the difference between the δ^(15)N values of a tissue and the diet depending on both the kind of tissue and the diet involved. The δ^(15)N values of collagen and chitin, biochemical components that are often preserved in fossil animal remains, are also related to the δ^(15)N value of the diet. The dependence of the δ^(15)N values of whole animals and their tissues and biochemical components on the δ^(15)N value of diet indicates that the isotopic composition of animal nitrogen can be used to obtain information about an animal's diet if its potential food sources had different δ^(15)N values. The nitrogen isotopic method of dietary analysis probably can be used to estimate the relative use of legumes vs non-legumes or of aquatic vs terrestrial organisms as food sources for extant and fossil animals. However, the method probably will not be applicable in those modern ecosystems in which the use of chemical fertilizers has influenced the distribution of nitrogen isotopes in food sources. The isotopic method of dietary analysis was used to reconstruct changes in the diet of the human population that occupied the Tehuacan Valley of Mexico over a 7000 yr span. Variations in the δ^(15)C and δ^(15)N values of bone collagen suggest that C_4 and/or CAM plants (presumably mostly corn) and legumes (presumably mostly beans) were introduced into the diet much earlier than suggested by conventional archaeological analysis.

5,548 citations

01 Jan 2016
TL;DR: The modern applied statistics with s is universally compatible with any devices to read, and is available in the digital library an online access to it is set as public so you can download it instantly.
Abstract: Thank you very much for downloading modern applied statistics with s. As you may know, people have search hundreds times for their favorite readings like this modern applied statistics with s, but end up in harmful downloads. Rather than reading a good book with a cup of coffee in the afternoon, instead they cope with some harmful virus inside their laptop. modern applied statistics with s is available in our digital library an online access to it is set as public so you can download it instantly. Our digital library saves in multiple countries, allowing you to get the most less latency time to download any of our books like this one. Kindly say, the modern applied statistics with s is universally compatible with any devices to read.

5,249 citations

Journal ArticleDOI
TL;DR: The precipitation maps show that the greatest potential for applying hydrogen and oxygen isotope forensics exists in mid- to high-latitude continental regions, where strong spatial isotope gradients exist and where strong, mechanistic relationships link precipitation and isotope ratios in biological tissue exist.
Abstract: Stable isotopes are being increasingly used in wildlife forensics as means of determining the origin and movement of animals. The heavy isotope content of precipitated water and snow (dDp, d 18 Op) varies widely and systematically across the globe, providing a label that is incorporated through diet into animal tissue. As a result, these isotopes are potentially ideal tracers of geo- graphic origin. The hydrogen and oxygen isotope tracer method has excellent potential where (1) spatial variation of precipitation isotopes exist, and (2) strong, mechanistic relationships link precipitation and isotope ratios in biological tissue. Here, we present a method for inter- polation of precipitation isotope values and use it to create global basemaps of growing-season (GS) and mean annual (MA) dDp and d 18 Op. The use of these maps for forensic application is demonstrated using previously published isotope data for bird feathers (dDf) in North America and Europe. The precipitation maps show that the greatest potential for applying hydrogen and oxygen isotope forensics exists in mid- to high-latitude conti- nental regions, where strong spatial isotope gradients exist. We demonstrate that dDf/dDp relationships have significant predictive power both in North America and Europe, and show how zones of confidence for the assignment of origin can be described using these predic- tive relationships. Our analysis focuses on wildlife forensics, but the maps and approaches presented here will be equally applicable to criminal forensic studies involving biological materials. These maps are available in GIS format at http://www.waterisotopes.org.

909 citations

Journal ArticleDOI
TL;DR: A review of recent studies shows heterogeneity in the magnitude and direction of size responses, exposing a need for large-scale phylogenetically controlled comparative analyses of temporal size change as mentioned in this paper, which will increase both understanding of the underlying mechanisms and physiological consequences of size shifts and therefore, the ability to predict the sensitivities of species to climate change.
Abstract: A recently documented correlate of anthropogenic climate change involves reductions in body size, the nature and scale of the pattern leading to suggestions of a third universal response to climate warming. Because body size affects thermoregulation and energetics, changing body size has implications for resilience in the face of climate change. A review of recent studies shows heterogeneity in the magnitude and direction of size responses, exposing a need for large-scale phylogenetically controlled comparative analyses of temporal size change. Integrative analyses of museum data combined with new theoretical models of size-dependent thermoregulatory and metabolic responses will increase both understanding of the underlying mechanisms and physiological consequences of size shifts and, therefore, the ability to predict the sensitivities of species to climate change.

830 citations

Journal ArticleDOI
TL;DR: Stable isotope patterns in nature are reviewed and recent tracking applications in a range of taxa are discussed and a series of key issues and assumptions are discussed to aid in the interpretation and design of effective and insightful isotope movement studies.
Abstract: Establishing patterns of movement of wild animals is crucial for our understanding of their ecology, life history and behavior, and is a prerequisite for their effective conservation. Advances in the use of stable isotope markers make it possible to track a diversity of animal species in a variety of habitats. This approach is revolutionizing the way in which we make connections between phases of the annual cycle of migratory animals. However, researchers must exercise care in their application of isotopic methods. Here, we review stable isotope patterns in nature and discuss recent tracking applications in a range of taxa. To aid in the interpretation and design of effective and insightful isotope movement studies, we discuss a series of key issues and assumptions. This exciting field will advance rapidly if researchers consider these aspects of study design and interpretation carefully.

805 citations