Patricia Brekke

Patricia Brekke
Zoological Society of London | IoZ · Institute of Zoology

About

37
Publications
8,128
Reads
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796
Citations
Citations since 2016
21 Research Items
489 Citations
2016201720182019202020212022020406080100
2016201720182019202020212022020406080100
2016201720182019202020212022020406080100
2016201720182019202020212022020406080100
Introduction
Patricia Brekke currently works at Zoological Society of London. Patricia does research in Genetics, Zoology and Evolutionary Biology.

Publications

Publications (37)
Article
The shape and intensity of natural selection can vary between years, potentially resulting in a chronic reduction of fitness as individuals need to track a continually changing optimum of fitness (i.e., a “lag load”). In endangered species, often characterized by small population size, the lack of genetic diversity is expected to limit the response...
Article
The rate of adaptive evolution, the contribution of selection to genetic changes that increase mean fitness, is determined by the additive genetic variance in individual relative fitness. To date, there are few robust estimates of this parameter for natural populations, and it is therefore unclear whether adaptive evolution can play a meaningful ro...
Article
Sample mix-ups occur when samples have accidentally been duplicated, mislabelled or swapped. When samples are subsequently genotyped or sequenced, this can lead to individual IDs being incorrectly linked to genetic data, resulting in incorrect or biased research results, or reduced power to detect true biological patterns. We surveyed the community...
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Full-text available
Fertility is fundamental to reproductive success, but not all copulation attempts result in a fertilized embryo. Fertilization failure is especially costly for females, but we still lack a clear understanding of the causes of variation in female fertility across taxa. Birds make a useful model system for fertility research, partly because their lar...
Article
Inbreeding can lead to a loss of heterozygosity in a population, and, when combined with genetic drift, may reduce the adaptive potential of a species. However, there is uncertainty about whether resequencing data can provide accurate and consistent inbreeding estimates. Here, we perform an in-depth inbreeding analysis for hihi (Notiomystis cincta)...
Article
Next generation sequencing has transformed the fields of ecological and evolutionary genetics by allowing for cost‐effective identification of genome‐wide variation. Single nucleotide polymorphism (SNP) arrays, or ‘SNP chips’, enable very large numbers of individuals to be consistently genotyped at a selected set of these identified markers, and al...
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Reproductive failure is ubiquitous. However, research on the mechanisms underpinning reproductive failure is still lacking in most species. This gap in our understanding has particularly strong repercussions for threatened species and it hinders our ability to establish effective interventions to improve survival. In this review, we focus on why eg...
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Significance Many ecological and evolutionary processes strongly depend on the way natural selection varies over time. However, a gap remains when trying to connect theoretical predictions to empirical work on this question: Most theory assumes that adaptation involves tracking a moving optimum phenotype through time, but this is seldom estimated e...
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In heterogeneous habitats, individuals sharing a larger part of their home-range are also likely to live in a very similar environment. This ‘common environment’ effect can generate phenotypic similarities between neighbours and lead to the structuring of phenotypes through the habitat. In this study, we used an intensely monitored population of hi...
Article
The qualitative and quantitative determination of trace elements is a stronghold of inductively coupled plasma–mass spectrometry (ICP-MS). Whereas in most cases the concentrations of a series of elements are determined in the bulk sample (often requiring a digestion upfront), the use of laser ablation (LA) in combination with ICP-MS allows further...
Article
To predict if a threatened species can adapt to changing selective pressures, it is crucial to understand the genetic basis of adaptive traits, especially in species historically affected by severe bottlenecks. We estimated the heritability of three hihi ( Notiomystis cincta ) morphological traits known to be under selection (nestling tarsus length...
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We used microsatellite DNA to assign probable parentage of young Corn Crakes to adult males and females and use these assignments to estimate the distribution of distances between broods of chicks and juveniles and the night‐time singing place of the father at the time of initiation of the clutch. Estimated distances for broods of young chicks were...
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Threatened species face numerous threats, including future challenges triggered by global change. A possible way to cope with these challenges is through adaptive evolution, which requires adaptive potential. Adaptive potential is defined as the genetic variance needed to respond to selection and can be assessed either on adaptive traits or fitness...
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Many bird species have been observed shifting their laying date to earlier in the year in response to climate change. However the vast majority of these studies were performed on non‐threatened species, less impacted by reduced genetic diversity (which is expected to limit evolutionary response) as a consequence of genetic bottlenecks, drift and po...
Article
Cambridge Core - Natural Resource Management, Agriculture, Horticulture and forestry - Species Conservation - edited by Jamieson A. Copsey
Chapter
Full-text available
Coccidia are intracellular parasites of the phylum Apicomplexa that cause a range of pathologies collectively termed coccidiosis. Species of coccidia of commercial importance have been well studied, with the effect of other species on passerine birds receiving increasing attention. In this chapter, we review the literature on coccidia in passerines...
Article
If environmental or maternal factors favor the fitness of one sex over the other, theory predicts that mothers should produce more offspring of the sex most likely to benefit from prevailing conditions. For species where males depend on carotenoid-based colorful ornaments to secure territory or attract mates, carotenoid availability in the environm...
Article
Size hierarchies are often seen when nestlings hatch asynchronously over a period of days. Shorter hatch periods are common across passerines, however, and while these may also give rise to asymmetries, their effects are rarely considered. Regardless of hatch period, the long-term consequences for later hatched nestlings that survive to fledge is u...
Article
Natal dispersal is a complex behaviour influenced by multiple factors that are often sex-specific and density-dependent. Reintroduced populations are typically low in density in the initial years of establishment; hence, understanding natal dispersal patterns in this context is a critical component of reintroduction biology. Natal dispersal is a ke...
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Floating males are usually thought of as nonbreeders. However, some floating individuals are able to reproduce through extra-pair copulations. Floater reproductive success can impact breeders’ sex ratio, reproductive variance, multiple paternity and inbreeding, particularly in small populations. Changes in reproductive variance alter the rate of ge...
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A new primer set was developed for sex-typing birds, Z37B. This primer set was designed to amplify al-leles of small size to render it suitable for sex-typing degraded samples, including shed feathers. This marker successfully sex-typed 50 % of the species tested, including passerines, shorebirds, rails, seabirds, eagles and the brown kiwi Apteryx...
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Measuring individual-level heterozygosity in threatened species is one approach to understanding and mitigating losses of genetic diversity and the role of inbreeding depression in those populations. In many conservation contexts, this goal is approached by assaying levels of microsatellite diversity, and inference is often extended to functional g...
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Why do some bird species show dramatic sexual dichromatism in their plumage? Sexual selection is the most common answer to this question. However, other competing explanations mean it is unwise to assume that all sexual dichromatism has evolved by this mechanism. Even if sexual selection is involved, further work is necessary to determine whether d...
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Sexual conflict can result in the evolution of extreme mating strategies, including forced copulation. Forced extrapair copulation (FEPC) is generally rare among birds, but is common in re-introduced populations of the hihi (Notiomystis cincta), a socially monogamous, New Zealand endemic, endangered passerine. The aim of this study was to understan...
Article
Providing supplementary food to endangered bird species is a common management action. Research has tended to focus on whether or not supplementary food should be provided, and relatively less attention has been paid to the form that food should take. Supplementation is also commonly made directly to adult individuals. However, the potentially long...
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In 1995 and 1996, release of 51 hihi (stitchbird, Notiomystis cincta) onto Tiritiri Matangi Island (wild caught on Hauturu, Little Barrier Island) marked the start of a research and ecological restoration success story. Although establishment of populations of hihi elsewhere in New Zealand has proven to be difficult, the population on Tiritiri Mata...
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Avoiding genetic incompatibility resulting from inbreeding is thought to be one of the main drivers of mate choice, promiscuity, and sexual conflict. Inbreeding avoidance has been found across a wide range of taxa and is predicted to be adaptive when the costs of inbreeding outweigh the benefits. This study tests the inbreeding avoidance hypothesis...
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Attempts to conserve threatened species by establishing new populations via reintroduction are controversial. Theory predicts that genetic bottlenecks result in increased mating between relatives and inbreeding depression. However, few studies of wild sourced reintroductions have carefully examined these genetic consequences. Our study assesses inb...
Article
The maintenance of genetic diversity is thought to be fundamental for the conservation of threatened species. It is therefore important to understand how genetic diversity is affected by the re-introduction of threatened species. We use establishment history and genetic data from the remnant and re-introduced populations of a New Zealand endemic bi...
Article
Many long-lived plant and animal species have nondiscrete overlapping generations. Although numerous models have been developed to predict the effective sizes (N(e)) of populations with overlapping generations, they are extremely difficult to apply to natural populations because of the large array of unknown and elusive life-table parameters involv...
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Dietary ingested carotenoid biomolecules have been linked to both improved health and immunity in nestling birds. Here, we test whether maternally invested egg carotenoids can offset the cost of parasitism in developing nestling hihi (Notiomystis cincta) from the bloodsucking mite (Ornithonyssus bursa). Our results reveal clear negative effects of...
Article
We have characterized 20 polymorphic microsatellite loci in the hihi Notiomystis cincta. Loci were identified by testing loci originally isolated in other avian species and by isolating new microsatellites from a hihi genomic library. These loci were characterized in unrelated hihi from a single population on Tiritiri Matangi Island (n = 98). Each...
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Full-text available
Sperm design and function are important determinants of male reproductive success and are expected to be under strong selection. The way that spermatozoa phenotypes evolve is poorly understood, because there have been few studies of the quantitative genetics of sperm. Here we show, in the zebra finch Taeniopygia guttata, an extraordinary degree of...

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