Pachytene karyotypes of 17 species of birds

Background: To date less than 10% of bird species have been karyotyped. They are rather conservative with diploid chromosome numbers about 78-80 in most species examined. Immunostaining of meiotic chromosomes at pachytene stage enables more precise estimates of the number, morphology and variability of macro- and microchromosomes than conventional analysis of mitotic metaphase chromosomes does. Analysis of pachytene chromosomes led to discovery of germline-restricted chromosome (GRC) that was present in germline cells and absent in somatic cells in all 16 species of passerine birds examined. GRC has not been found in any non-passerine bird. Results: In this study, using immunolocalization of SYCP3, the main protein of the lateral elements of the synaptonemal complex (SC) and centromere proteins we examined male pachytene karyotypes of sixteen passerine species and one outgroup species the Common cuckoo Cuculus canorus and provided their idiograms and precise estimates of their diploid chromosome numbers and the numbers of chromosome arms. We provided the first description of the karyotypes of three species, corrected the published data on the karyotypes of ten species and confirmed them for four species. The pachytene cells of the Gouldian finch, Brambling and Common linnet contained heteromorphic bivalents indicating heterozygosity for inversions or centromere shifts. The European pied flycatcher, Gouldian finch and Domestic canary have extended centromeres in several macro- and microchromosomes. GRCs of various sizes and shapes were detected in all passerine species examined. Their chromatin was heavily labeled by anticentromere antibodies. The lateral elements of the GRC SC varied in their size from the largest to the smallest element of the pachytene karyotype. They also varied in shape from continuous to fragmented. Conclusions: All songbirds examined, except the Eurasian skylark, have highly conservative karyotypes, 2n=80-82+GRC with seven pairs of macrochromosomes and 33-34 pairs of microchromosomes. The interspecies differences concern the sizes of the macrochromosomes, morphology of the microchromosomes and sizes of the centromeres. GRC is present in all songbird species examined, varying in size, morphology and SC structure even between closely related species. This indicates its fast evolution.

The use of Passeriformes in the eastern Amazonia of Brazil: culture encourages hunting and profit encourages trade

This study characterized the ethnoornithological knowledge of passerine bird keepers, known locally as criadores or passarinheiros, who capture, train, breed and sell wild species in the eastern Amazonia of Brazil. The data were collected from 62 bird keepers through informal, semi-structured interviews and participant observation. The family Thraupidae was the most captured group, with 23 species used, predominantly of the genus Sporophila. Sporophila angolensis had the highest use value and price. Our findings suggest that conservation strategies should be a priority for Sporophila maximiliani, S. angolenses and Saltator maximus. The Passeriformes are obtained by capturing them from the wild, by captive breeding or in trade. They are trapped and sold locally, in nearby municipalities, and also in more distant locations as far as the border with Suriname, French Guiana and Guyana. On the international market, sale prices can reach USD 5,400 per individual bird. Species with both significant economic value and regional cultural significance are of the greatest importance to the bird keepers. To mitigate the negative effects of this activity, we recommend implementation of environmental education programmes for bird keepers, to improve their capacity to raise awareness about wildlife, and to inform them of the legal processes for bird keeping and for breeding birds in captivity for legal trade. Long-term strategies for bird conservation should also be considered, such as the implementation of ecotourism in protected areas to encourage the practice of birdwatching.

Algerian Nuthatch (Sitta ledanti Vielliard, 1976): Current challenges of an endemic species

The Algerian Nuthatch (Sitta ledanti) is the emblematic bird species of Kabylia of Babors. It is a medium-sized passerine bird species of the Sittidae family. Jean-Paul Ledant discovered this species in October 1975, on the Babor Mountain. Twelve other forests in North-East Algeria has been discovered as breeding sites. These are the forests of the Babors region, in Kabylia. The Algerian Nuthatch was observed mainly in oak, cedar and pine habitats. It is mainly granivorous in winter and an insectivorous in spring/summer or breeding season, which starts in March and can last until July. The incubation period lasts from 14 to 17 days, with clutches of six eggs. The Algerian Nuthatch is listed as an endangered species by IUCN and is protected by the Algerian laws. However, many threats to the environment, such as tree felling and fires, are threatening the species.

What is the best fitness measure in wild populations? A case study on the power of short-term fitness proxies to predict reproductive value

Fitness is at the core of evolutionary theory, but it is difficult to measure accurately. One way to measure long-term fitness is by calculating the individual’s reproductive value, which represents the expected number of allele copies an individual passes on to distant future generations. However, this metric of fitness is scarcely used because the estimation of individual’s reproductive value requires long-term pedigree data, which is rarely available in wild populations where following individuals from birth to death is often impossible. Wild study systems therefore use short-term fitness metrics as proxies, such as the number of offspring produced. This study obtained three frequently used short-term proxies for fitness obtained at different offspring life stages (eggs, hatchlings, fledglings and recruits), and compared their ability to predict reproductive values derived from the genetic pedigree of a wild passerine bird population. We used twenty years of precise field observations and a near-complete genetic pedigree to calculate reproductive success, individual growth rate and de-lifed fitness as lifetime fitness measures, and as annual de-lifed fitness. We compared the power of these metrics to predict reproductive values and lineage survival to the end of the study period. The three short-term fitness proxies predict the reproductive values and lineage survival only when measured at the recruit stage. There were no significant differences between the different fitness proxies at the same offspring stages in predicting the reproductive values and lineage survival. Annual fitness at one year old predicted reproductive values equally well as lifetime de-lifed fitness. However, none of the short-term fitness proxies was strongly associated with the reproductive values. In summary, the commonly short-term fitness proxies capture long-term fitness with intermediate accuracy at best, if measured at recruitment stage. As lifetime fitness measured at recruit stage and annual fitness in the first year of life were the best proxies of long-term fitness, we encourage their future use.

First microsatellite markers for the European Robin (Erithacus rubecula) and their application in analysis of parentage and genetic diversity

The European Robin is a small passerine bird associated with woodlands of Eurasia and North Africa. Despite being relatively widespread and common, little is known of the species’ breeding biology and genetic diversity. We used Next Generation Sequencing (NGS) to develop and characterize microsatellite markers for the European Robin, designing three multiplex panels to amplify 14 microsatellite loci. The level of polymorphism and its value for assessing parentage and genetic structure was estimated based on 119 individuals, including seven full families and 69 unrelated individuals form Poland’s Białowieża Primaeval Forest and an additional location in Portugal. All markers appeared to be highly variable. Analysis at the family level confirmed a Mendelian manner of inheritance in the investigated loci. Genetic data also revealed evidence for extra-pair paternity in one family. The set of markers that we developed are proven to be valuable for analysis of the breeding biology and population genetics of the European Robin.

Body temperature is a repeatable trait in a free-ranging passerine bird

Body temperature (Tb) affects animal function through its influence on rates of biochemical and biophysical reactions, the molecular structures of proteins and tissues, and ultimately, organismal performance. Despite its importance in driving physiological processes, there are few data on how much variation in Tb exists within populations of organisms, and whether this variation consistently differs among individuals over time (i.e., repeatability of a trait). Here, using thermal radio-frequency identification implants, we quantified the repeatability of Tb, both in the context of a fixed average environment (∼21 °C) and across ambient temperatures (6 – 31 °C), in a free-living population of tree swallows (Tachycineta bicolor, n=16). By experimentally trimming the ventral plumage of a subset of female swallows (n=8), we also asked whether the repeatability of Tb is influenced by the capacity to dissipate body heat. We found that both female and male tree swallow Tb was repeatable at 21 °C (R=0.89 – 92), but female Tb was less repeatable than male Tb across ambient temperature (Rfemale=0.10, Rmale=0.58), which may be due to differences in parental investment. Trimmed birds had on average lower Tb than control birds (by ∼0.5 °C), but the repeatability of female Tb did not differ as a function of heat dissipation capacity. This suggests that trimmed individuals adjusted their Tb to account for the effects of heat loss on Tb. Our study provides evidence a first critical step toward understanding if Tb is responsive to natural selection, and for predicting how animal populations will respond to climatic warming.