Variation in feather corticosterone levels in Alpine swift nestlings provides support for the hypo-responsive hypothesis

Acknowledgements: The authors would like to thank the numerous students who helped collecting data in the field and the city council of Solothurn for access the Bieltor tower. SJE would like to thank Benedetta Catitti for producing the figures and Lukas Jenni for valuable comments on the manuscript. This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.Peer reviewedPostprintPublisher PD

Notas sobre philornis vulgaris (couri, 1984) (diptera: muscidae) en nidos del sinsonte tropical mimus gilvus (viellot, 1808) en los Andes de Colombia

Between September 2005 and April 2006 we observed 20 nests and 42 nestlings of the tropical mockingbird, Mimus gilvus (Vieillot, 1808) in Villa de Leiva, Boyacá, Colombia. 40% of all nestlings (40% of the nests) showed some level of myiasis or subcutaneous infestation by fly larvae (Diptera: Muscidae). The larvae collected from one of the nestlings were reared and identified as Philornis vulgaris Couri 1984, constituting the first record for this species in Colombia

Exploring the causes of heterozygosity-fitness correlations in the blue tit

For this thesis I studied heterozygosity-fitness correlations (HFC) in a natural population of a passerine bird, the blue tit (Cyanistes caeruleus), that was carefully monitored during nine years. In a first step, I characterized a set of at least 95 polymorphic microsatellite loci with utility for population genetic studies in the blue tit (Chapter 1). I classified the markers as presumably functional or neutral by considering whether the genomic region where the markers are located is transcribed to RNA and therefore expressed. This classification captured differences in the characteristics of the loci (e.g. number of alleles, expected heterozygosity, distance to genes) that would be expected to occur between markers with genuine differences in functionality (Chapter 2). In a first approach for investigating HFC in the blue tit population, I used a sample of breeding birds with varying levels of inbreeding. With this approach, I found positive correlations between multilocus heterozygsity at neutral markers and three reproductive and one survival traits (Chapters 2 and 3). Supporting a role of inbreeding on the detected HFC, I documented 1) some consanguineous matings, 2) a particular type of population structure that can contribute to the occurrence of inbreeding events, and 3) identity disequilibrium (i.e. the correlation between heterozygosity or homozygosity across loci within individuals, caused by inbreeding) with all markers and with the group of neutral loci (Chapter 2). In a second approach for investigating HFC, I controlled for the level of inbreeding by using groups of full-siblings (Chapter 3). In this case, the correlations between multilocus heterozygosity and two estimates of early survival were detected only with the group of functional markers and were negative. These correlations are better explained by localized effects at single loci. Generally, heterozygosity at single loci did not show disproportionately large and consistent effects on the phenotypic traits considered. The results of this thesis highlight the importance of considering the putative functionality of the markers when interpreting the results of HFC studies, the use and limitations of HFC to reveal genotype – phenotype associations, and the value of a thorough consideration of the population processes causing HFC

Cangrejo ermitaño - busca casa móvil

Los cangrejos ermitaños viven en varios tipos de ecosistemas y por tanto se encuentran extendidos por el planeta, en los océanos, costas, ríos, lagos, esteros y ciénegas. Geográficamente, se distribuyen por las costas de todos los continentes, particularmente a lo largo de las costas tropicales y subtropicales. La mayoría de estos crustáceos son omnívoros detritívoros. Su principal fuente de nutrición son los detritos y pueden alimentarse de pedazos de animales vivos y muertos. El factor nutricional no es un factor limitante, ya que se ha visto que no ocurre una división de nichos para el alimento entre las especie

Data from: Heterozygosity and survival in blue tits (Cyanistes caeruleus): contrasting effects of presumably functional and neutral loci

The relationship between genetic diversity and fitness has important implications in evolutionary and conservation biology. This relationship has been widely investigated at the individual level in studies of heterozygosity-fitness correlations (HFC). General effects due to inbreeding and/or local effects at single loci have been used as explanations of HFC, but the debate about the causes of HFC in open, natural populations is still ongoing. Study designs that control for variation in the inbreeding level of the individuals, and knowledge on the function and location of the markers used to measure heterozygosity, are fundamental to understand the causes of HFC. Here we investigated correlations between individual heterozygosity and estimates of survival at different life-history stages in an open population of blue tits (Cyanistes caeruleus). For survival at the embryo, nestling and fledgling stage we used a full-sibling approach, i.e. we controlled for the level of inbreeding. We genotyped 1496 individuals with 79 microsatellites distributed across 25 chromosomes in another passerine and classified either as potentially functional (58 loci) or neutral (21 loci). We found different effects of standardized multilocus heterozygosity (SH): SHfunctional had a negative effect on the probability of hatching and local recruitment of females, whereas SHneutral had a positive effect on adult survival. The negative effects of functional loci are better explained by local effects, whereas the positive effects of neutral markers could reflect inbreeding effects in the population. Our results highlight the importance of considering the characteristics of the markers used in HFC studies and confirm the mixed effects of heterozygosity in different contexts (e.g. sex and life-history stage)

Data from: Correlations between heterozygosity and reproductive success in the blue tit (Cyanistes caeruleus): an analysis of inbreeding and single locus effects

In order to understand the mechanisms behind heterozygosity-fitness correlations (HFC), it is necessary to employ large numbers of markers with known function and to independently estimate the variation in inbreeding in the population. Here we genotyped 794 blue tits with 79 microsatellites that were distributed across 25 chromosomes and that were classified either as "functional" (N = 58) or "neutral" (N = 21). We found a positive effect of individual heterozygosity at multiple loci on clutch size, on the number of eggs sired by males, and on the number of recruits produced by males and females. We documented the occurrence of some consanguineous matings and found evidence for a particular type of population structure that can contribute to the occurrence of inbreeding. As the set of "neutral" loci provided more power to detect HFC and identity disequilibrium, we argue that "neutral" markers are better predictors of the effects of inbreeding. The number of significant effects at single loci did not exceed the expected number of false positives and no strong effects were associated with heterozygosity at "functional" markers. Thus, the HFC found here cannot be attributed to strong effects of the loci under study

Yearling survival data

Survival until next breeding seasons (survival) are listed for all yearlings. Year of first breeding season (season), sex (1 = male, 2 = female) and recruitment status (1 = local recruit, 0 = immigrant) are added

Reproductive success of each nest (breeding pair)

Reproductive success information per nest is given as clutch size, no. of hatchlings, no. of fledglings and no. of recruits to the next breeding season. Age is coded as 1 (one year old) or 2 (two or more years old)

Sired eggs of all males and breeding seasons

Number sired eggs per male and breeding season is listed. Age of the male is coded as 1 (one year old) or 2 (two or more years old)

Clutch sizes of all females and breeding seasons

Clutch sizes (no. of eggs) per female and breeding season are listed. Age of the female is coded as 1 (one year old) or 2 (two or more years old)