Neighbouring-group composition and within-group relatedness drive extra-group paternity rate in the European badger (Meles meles)

Extra-group paternity (EGP) occurs commonly among group-living mammals and plays an important role in mating systems and the dynamics of sexual selection; however, socio-ecological and genetic correlates of EGP have been underexplored. We use 23 years of demographic and genetic data from a high-density European badger (Meles meles) population, to investigate the relationship between the rate of EGP in litters and mate availability, mate incompatibility and mate quality (heterozygosity). Relatedness between within-group assigned mothers and candidate fathers had a negative quadratic effect on EGP, whereas the number of neighbouring-group candidate fathers had a linear positive effect. We detected no effect of mean or maximum heterozygosity of within-group candidate fathers on EGP. Consequently, EGP was associated primarily with mate availability, subject to within-group genetic effects, potentially to mitigate mate incompatibility and inbreeding. In badgers, cryptic female choice, facilitated by superfecundation, superfoetation and delayed implantation, prevents males from monopolizing within-group females. This resonates with a meta-analysis in group-living mammals, which proposed that higher rates of EGP occur when within-group males cannot monopolize within-group females. In contrast to the positive meta-analytic association, however, we found that EGP associated negatively with the number of within-group assigned mothers and the number of within-group candidate fathers; potentially a strategy to counter within-group males committing infanticide. The relationship between the rate of EGP and socio-ecological or genetic factors can therefore be intricate, and the potential for cryptic female choice must be accounted for in comparative studies

Physiological integration of coral colonies is correlated with bleaching resistance

Inter-module physiological integration of colonial organisms can facilitate colony-wide coordinated responses to stimuli that strengthen colony fitness and stress resistance. In scleractinian corals, whose colonial integration ranges from isolated polyps to a seamless continuum of polyp structures and functions, this coordination improves responses to injury, predation, disease, and stress and may be one of the indications of an evolutionary origin of Symbiodinium symbiosis. However, observations of species-specific coral bleaching patterns suggest that highly integrated coral colonies may be more susceptible to thermal stress, and support the hypothesis that communication pathways between highly integrated polyps facilitate the dissemination of toxic byproducts created during the bleaching response. Here we reassess this hypothesis by parameterizing an integration index using 7 skeletal features that have been historically employed to infer physiological integration. We examine the relationship between this index and bleaching response across a phylogeny of 88 diverse coral species. Correcting for phylogenetic relationships among species in the analyses reveals significant patterns among species characters that could otherwise be obscured in simple cross-species comparisons using standard statistics, whose assumptions of independence are violated by the shared evolutionary history among species. Similar to the observed benefits of in creased coloniality for other types of stressors, the results indicate a significantly reduced bleaching response among coral species with highly integrated colonies

Pengembangan Media Pembelajaran Matematika Berbantu Wondershare dengan Pendekatan Rme pada Materi SMP

Pemilihan media pembelajaran yang kurang tepat dapat membuat siswa kurang antusias terhadap mata pelajaran matematika. Sehingga banyak siswa yang mendapat nilai dibawah KKM. Solusinya dibutuhkan media pembelajaran yang menarik serta dapat menumbuhkan antusias siswa dalam belajar.Penelitian ini bertujuan untuk mengembangkan media pembelajaran berbantu wondershare dengan pendekatan RME sehingga menghasilkan media yang layak dan efektif digunakan selama pembelajaran. Jenis penelitian ini adalah penelitian Research and Development dengan menggunakan model pengembangan ADDIE, terdiri dari 5 tahapan yaitu analisis, design, developmen, implementasi, evaluasi.Sebelum diimplementasikan, media pembelajaran terlebih dahulu dilakukan uji validasi oleh ahli media, ahli materi serta angket tanggapan siswa. Hasil validasi ahli tersebut berkriteria sangat baik sehingga media pembelajaran layak untuk digunakan.Pembelajaran dengan media pembelajaran berbantu wondershare dengan pendekatan RME efektif digunakan oleh peserta didik. Hal ini di buktikan dari rata rata kelas eksperimen dan kontrol yaitu 82,03 dan 60,54. Ketuntasan belajar individu kelas ekperimen terdapat 31 siswa tuntas dari 36 siswa, dan kelas kontrol terdapat 8 siswa tuntas dari 27 siswa. Dilihat dari ketuntasan belajar klasikal siswa untuk kelas kontrol dan eksperimen sebesar 22,86% dan 86,11%. Dengan analisis menggunakan uji t pihak kanan diperoleh nilaiyaitu 9,607>1,667 maka H0 ditolak, jadi pembelajaran dengan menggunakan media pembelajaran berbantuan wondershare dengan pendekatan RME lebih baik dibandingkan dengan pembelajaran konvensional pada materi SMP

Extrapair paternity in two populations of the socially monogamous Thorn-tailed Rayadito Aphrastura spinicauda (Passeriformes: Furnariidae)

Studies on extrapair paternity (EPP) are key to understanding the ecological and evolutionary drivers of variation in avian mating strategies, but information is currently lacking for most tropical and subtropical taxa. We describe the occurrence of EPP in two populations of a South American socially monogamous bird, the Thorn-tailed Rayadito, based on data from 266 broods and 895 offspring that were sampled during six breeding seasons in north-central and southern Chile. In the northern population, 21% of the broods contained at least one extrapair young and 14% of all offspring were sired by an extrapair male, while in the southern population, we detected extrapair offspring (EPO) in 14% of the broods, and 6% of all offspring were EPO. Variation in the frequency of EPP could stem from population differences in the duration of the breeding season or the density of breeding individuals. Other factors such as differences in breeding synchrony and variation in food availability need to be evaluated. More reports on EPP rates are necessary to determine the patterns of taxonomic and geographic variation in mating strategies in Neotropical birds, and to better understand the differences in ecological dynamics between northern and southern hemisphere populations.Fil: Botero Delgadillo, Esteban. Max Plank Institute For Ornithology; Alemania. SELVA: Investigación para la Conservación en el Neotrópico; Colombia. Universidad de Chile; ChileFil: Quirici, Verónica. Universidad Andrés Bello; ChileFil: Poblete, Yanina. Universidad de Las Américas; ChileFil: Ippi, Silvina Graciela. Universidad Nacional del Comahue. Centro Regional Universitario Bariloche. Departamento de Ecología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; ArgentinaFil: Kempenaers, Bart. Max Plank Institute For Ornithology; AlemaniaFil: Vásquez, Rodrigo A.. Universidad de Chile; Chil

Male age is associated with extra-pair paternity, but not with extra-pair mating behaviour

Extra-pair paternity is the result of copulation between a female and a male other than her social partner. In socially monogamous birds, old males are most likely to sire extra-pair offspring. The male manipulation and female choice hypotheses predict that age-specific male mating behaviour could explain this old-over-young male advantage. These hypotheses have been difficult to test because copulations and the individuals involved are hard to observe. Here, we studied the mating behaviour and pairing contexts of captive house sparrows, Passer domesticus. Our set-up mimicked the complex social environment experienced by wild house sparrows. We found that middle-aged males, which would be considered old in natural populations, gained most extra-pair paternity. However, both, female solicitation behaviour and subsequent extra-pair matings were not associated with male age. Further, copulations were more likely when solicited by females than when initiated by males (i.e. unsolicited copulations). Male initiated within-pair copulations were more common than male initiated extra-pair copulations. To conclude, our results did not support either hypothesis regarding age-specific male mating behaviour. Instead, female choice, independent of male age, governed copulation success, especially in an extra-pair context. Post-copulatory mechanisms might determine why older males sire more extra-pair offspring

Maximum Host Survival at Intermediate Parasite Infection Intensities

BACKGROUND: Although parasitism has been acknowledged as an important selective force in the evolution of host life histories, studies of fitness effects of parasites in wild populations have yielded mixed results. One reason for this may be that most studies only test for a linear relationship between infection intensity and host fitness. If resistance to parasites is costly, however, fitness may be reduced both for hosts with low infection intensities (cost of resistance) and high infection intensities (cost of parasitism), such that individuals with intermediate infection intensities have highest fitness. Under this scenario one would expect a non-linear relationship between infection intensity and fitness. METHODOLOGY/PRINCIPAL FINDINGS: Using data from blue tits (Cyanistes caeruleus) in southern Sweden, we investigated the relationship between the intensity of infection of its blood parasite (Haemoproteus majoris) and host survival to the following winter. Presence and intensity of parasite infections were determined by microscopy and confirmed using PCR of a 480 bp section of the cytochrome-b-gene. While a linear model suggested no relationship between parasite intensity and survival (F = 0.01, p = 0.94), a non-linear model showed a significant negative quadratic effect (quadratic parasite intensity: F = 4.65, p = 0.032; linear parasite intensity F = 4.47, p = 0.035). Visualization using the cubic spline technique showed maximum survival at intermediate parasite intensities. CONCLUSIONS/SIGNIFICANCE: Our results indicate that failing to recognize the potential for a non-linear relationship between parasite infection intensity and host fitness may lead to the potentially erroneous conclusion that the parasite is harmless to its host. Here we show that high parasite intensities indeed reduced survival, but this effect was masked by reduced survival for birds heavily suppressing their parasite intensities. Reduced survival among hosts with low parasite intensities suggests costs of controlling parasite infections; however, the nature of such costs remains to be elucidated

Skeletal Light-Scattering Accelerates Bleaching Response in Reef-Building Corals

Background At the forefront of ecosystems adversely affected by climate change, coral reefs are sensitive to anomalously high temperatures which disassociate (bleaching) photosynthetic symbionts (Symbiodinium) from coral hosts and cause increasingly frequent and severe mass mortality events. Susceptibility to bleaching and mortality is variable among corals, and is determined by unknown proportions of environmental history and the synergy of Symbiodinium- and coral-specific properties. Symbiodinium live within host tissues overlaying the coral skeleton, which increases light availability through multiple light-scattering, forming one of the most efficient biological collectors of solar radiation. Light-transport in the upper ~200 μm layer of corals skeletons (measured as ‘microscopic’ reduced-scattering coefficient, μ′S,m), has been identified as a determinant of excess light increase during bleaching and is therefore a potential determinant of the differential rate and severity of bleaching response among coral species. Results Here we experimentally demonstrate (in ten coral species) that, under thermal stress alone or combined thermal and light stress, low-μ′S,m corals bleach at higher rate and severity than high-μ′S,m corals and the Symbiodinium associated with low-μ′S,m corals experience twice the decrease in photochemical efficiency. We further modelled the light absorbed by Symbiodinium due to skeletal-scattering and show that the estimated skeleton-dependent light absorbed by Symbiodinium (per unit of photosynthetic pigment) and the temporal rate of increase in absorbed light during bleaching are several fold higher in low-μ′S,m corals. Conclusions While symbionts associated with low-μ′S,m corals receive less total light from the skeleton, they experience a higher rate of light increase once bleaching is initiated and absorbing bodies are lost; further precipitating the bleaching response. Because microscopic skeletal light-scattering is a robust predictor of light-dependent bleaching among the corals assessed here, this work establishes μ′S,m as one of the key determinants of differential bleaching response

Massive Nest-Box Supplementation Boosts Fecundity, Survival and Even Immigration without Altering Mating and Reproductive Behaviour in a Rapidly Recovered Bird Population

Habitat restoration measures may result in artificially high breeding density, for instance when nest-boxes saturate the environment, which can negatively impact species' demography. Potential risks include changes in mating and reproductive behaviour such as increased extra-pair paternity, conspecific brood parasitism, and polygyny. Under particular cicumstances, these mechanisms may disrupt reproduction, with populations dragged into an extinction vortex. With the use of nuclear microsatellite markers, we investigated the occurrence of these potentially negative effects in a recovered population of a rare secondary cavity-nesting farmland bird of Central Europe, the hoopoe (Upupa epops). High intensity farming in the study area has resulted in a total eradication of cavity trees, depriving hoopoes from breeding sites. An intensive nest-box campaign rectified this problem, resulting in a spectacular population recovery within a few years only. There was some concern, however, that the new, high artificially-induced breeding density might alter hoopoe mating and reproductive behaviour. As the species underwent a serious demographic bottleneck in the 1970–1990s, we also used the microsatellite markers to reconstitute the demo-genetic history of the population, looking in particular for signs of genetic erosion. We found i) a low occurrence of extra-pair paternity, polygyny and conspecific brood parasitism, ii) a high level of neutral genetic diversity (mean number of alleles and expected heterozygosity per locus: 13.8 and 83%, respectively) and, iii) evidence for genetic connectivity through recent immigration of individuals from well differentiated populations. The recent increase in breeding density did thus not induce so far any noticeable detrimental changes in mating and reproductive behaviour. The demographic bottleneck undergone by the population in the 1970s-1990s was furthermore not accompanied by any significant drop in neutral genetic diversity. Finally, genetic data converged with a concomitant demographic study to evidence that immigration strongly contributed to local population recovery

Do Individual Females Differ Intrinsically in Their Propensity to Engage in Extra-Pair Copulations?

BACKGROUND: While many studies have investigated the occurrence of extra-pair paternity in wild populations of birds, we still know surprisingly little about whether individual females differ intrinsically in their principal readiness to copulate, and to what extent this readiness is affected by male attractiveness. METHODOLOGY/FINDINGS: To address this question I used captive zebra finches (Taeniopygia guttata) as a model system. I first measured female readiness to copulate when courted by a male for the first time in life. Second, I conducted choice-chamber experiments to assess the mating preferences of individual females prior to pair formation. I then paired females socially with a non-desired mate and once they had formed a stable pair bond, I observed the inclination of these females to engage in extra-pair copulations with various males. Females showing a high readiness to copulate when courted by a male for the first time in life were much more likely to engage in extra-pair copulations later in life than others. Male attractiveness, as measured in choice tests, was a useful predictor of whether females engaged in extra-pair copulations with these males, but, surprisingly, the attractiveness of a female's social partner had no effect on her fidelity. However, it remained unclear what made some males more attractive than others. Contrary to a widespread but rarely tested hypothesis, females did not preferentially copulate with males having a redder beak or singing at a higher rate. Rather it seemed that song rate was a confounding factor in choice-chamber experiments: song attracted the female's attention but did not increase the male's attractiveness as a copulation partner. CONCLUSIONS/SIGNIFICANCE: Intrinsic variation in female readiness to copulate as well as variation in the attractiveness of the extra-pair male but not the social partner decided the outcome of extra-pair encounters