Passerines are the most successfully diversified bird order (around 60% of all avian species). They have developed complicated songs to defend their territories and to attract females for mating that ...can evolve quickly due to cultural transmission. Complex singing as well as plumage coloration of male birds are honest signals for potential partners and provide information about the males’ quality. To function as honest signals, both traits must be costly for the males. Of course, not all passerine species are equally clever or beautiful. Even within a single family of 50 to 70 species, relevant traits may vary considerably. Tits and chickadees (Paridae) comprise species of similar size, varying a lot in coloration and plumage pattern. The territorial songs are relatively short and simple. We investigated the relationship between song complexity and plumage coloration, taking phylogenetic relationships into account. We studied 55 out of the 64 species with 1084 song recordings retrieved from an online database. In the best model, besides colorfulness, body size had a negative impact on song complexity. Large colorful species were found to sing less complex songs. This result supports the hypothesis of a trade-off between costly traits and their likely intense signal function. This study contributes to a better understanding of how sexual selection influences the diversification of traits. In addition, we found that despite the relatively uniform size, the general negative correlation between body size and song frequency can be recovered. Some song traits are further influenced by distribution and thus by interspecific differences in climate niche.
Located at the crossroads of two continents and at the southeastern edge of the Mediterranean Basin, Anatolia was one of the most important Pleistocene glacial refugia in the Western Palaearctic. As ...part of the Irano-Anatolian, Caucasus and Mediterranean Basin biodiversity hotspots, this region is also home to a rich avian community including nearly 400 breeding species. Nevertheless, research addressing the genetic structure and diversity of local bird populations is limited, and information on glacial refugia in this region is still scant, especially when compared to other large Mediterranean peninsulas, namely the Balkan, Italian and Iberian ones. In this study, we contribute to filling this gap by addressing the biogeographic pattern of four common resident songbirds—the Eurasian blue tit (Cyanistes caeruleus), the great tit (Parus major), the Eurasian chaffinch (Fringilla coelebs) and the Eurasian blackbird (Turdus merula)—and one endemic species—the Krüper’s nuthatch (Sitta krueperi)—by amplifying two mitochondrial DNA genes in individuals from Anatolia (n = 329) and comparing their sequences to those of conspecifics from the rest of their distribution range across the western Palaearctic (n = 357) deposited in public databases. The overall genetic structure of these species is consistent with a scenario of isolation for multiple populations in different refugia across Anatolia and subsequent secondary contact in the wake of ice retreat, which makes this region a hotspot of genetic diversity for both widespread and endemic avian species.
Bird Species Tietze, Dieter Thomas
2018, 2018-11-19
eBook
Open access
The average person can name more bird species than they think, but do we really know what a bird “species” is? This open access book takes up several fascinating aspects of bird life to elucidate ...this basic concept in biology. From genetic and physiological basics to the phenomena of bird song and bird migration, it analyzes various interactions of birds – with their environment and other birds. Lastly, it shows imminent threats to birds in the Anthropocene, the era of global human impact. Although it seemed to be easy to define bird species, the advent of modern methods has challenged species definition and led to a multidisciplinary approach to classifying birds. One outstanding new toolbox comes with the more and more reasonably priced acquisition of whole-genome sequences that allow causative analyses of how bird species diversify. Speciation has reached a final stage when daughter species are reproductively isolated, but this stage is not easily detectable from the phenotype we observe. Culturally transmitted traits such as bird song seem to speed up speciation processes, while another behavioral trait, migration, helps birds to find food resources, and also coincides with higher chances of reaching new, inhabitable areas. In general, distribution is a major key to understanding speciation in birds. Examples of ecological speciation can be found in birds, and the constant interaction of birds with their biotic environment also contributes to evolutionary changes. In the Anthropocene, birds are confronted with rapid changes that are highly threatening for some species. Climate change forces birds to move their ranges, but may also disrupt well-established interactions between climate, vegetation, and food sources. This book brings together various disciplines involved in observing bird species come into existence, modify, and vanish. It is a rich resource for bird enthusiasts who want to understand various processes at the cutting edge of current research in more detail. At the same time it offers students the opportunity to see primarily unconnected, but booming big-data approaches such as genomics and biogeography meet in a topic of broad interest. Lastly, the book enables conservationists to better understand the uncertainties surrounding “species” as entities of protection.
Aim: Zoogeographie patterns in the Himalayas and their neighbouring Southeast Asian mountain ranges include elevational parapatry and ecological segregation, particularly among passerine bird ...species. We estimate timings of lineage splits among close relatives from the north Palaearctic, the Sino-Himalayan mountain forests and from adjacent Southeast Asia. We also compare phylogeographic affinities and timing of radiation among members of avian communities from different elevational belts. Location: East Asia. Methods: We reconstructed molecular phylogenies based on a mitochondrial marker (cytochrome b) and multilocus data sets for seven passerine groups: Aegithalidae, Certhiidae (Certhia), Fringillidae (Pyrrhula) y Paridae (Periparus), Phylloscopidae, Regulidae and Timaliidae (Garrulax sensu lato). Molecular dating was carried out using a Bayesian approach applying a relaxed clock in BEAST. Time estimates were inferred from three independent calibrations based on either a fixed mean substitution rate or fixed node ages. The biogeographic history of each group was reconstructed using a parsimony-based approach. Results: Passerine radiation in Southeast Asia can be divided into roughly three major phases of separation events. We infer that an initial Miocene radiation within the Southeast Asian region included invasions of (sub) tropical faunal elements from the Indo-Burmese region to the Himalayan foothills and further successive invasions to Central Asia and Taiwan towards the early Pliocene. During two further Pliocene/Pleistocene phases, the subalpine mountain belt of the Sino-Himalayas was initially invaded by boreal species with clear phylogenetic affinities to the north Palaearctic taiga belt. Most terminal splits between boreal Himalayan/Chinese sister taxa were dated to the Pleistocene. Main conclusions: Extant patterns of elevational parapatry and faunal transition in the Sino-Himalayas originated from successive invasions from different climatic regions. The initiation of Southeast Asian passerine diversification and colonization of the Himalayan foothills in the mid-Miocene coincides with the postulated onset of Asian monsoon climate and the resulting floral and faunal turnovers. Patterns of elevational parapatry were established by southward invasions of boreal avifaunal elements to the subalpine Sino-Himalayan forest belt that were strongly connected to climate cooling towards the end of the Pliocene. Current patterns of allopatry and parapatry in boreal species (groups) were shaped through Pleistocene forest fragmentation in East Asia.
Encompassing some of the major hotspots of biodiversity on Earth, large mountain systems have long held the attention of evolutionary biologists. The region of the Qinghai‐Tibet Plateau (QTP) is ...considered a biogeographic source for multiple colonization events into adjacent areas including the northern Palearctic. The faunal exchange between the QTP and adjacent regions could thus represent a one‐way street (“out of” the QTP). However, immigration into the QTP region has so far received only little attention, despite its potential to shape faunal and floral communities of the QTP. In this study, we investigated centers of origin and dispersal routes between the QTP, its forested margins and adjacent regions for five clades of alpine and montane birds of the passerine superfamily Passeroidea. We performed an ancestral area reconstruction using BioGeoBEARS and inferred a time‐calibrated backbone phylogeny for 279 taxa of Passeroidea. The oldest endemic species of the QTP was dated to the early Miocene (ca. 20 Ma). Several additional QTP endemics evolved in the mid to late Miocene (12–7 Ma). The inferred centers of origin and diversification for some of our target clades matched the “out of Tibet hypothesis’ or the “out of Himalayas hypothesis” for others they matched the “into Tibet hypothesis.” Three radiations included multiple independent Pleistocene colonization events to regions as distant as the Western Palearctic and the Nearctic. We conclude that faunal exchange between the QTP and adjacent regions was bidirectional through time, and the QTP region has thus harbored both centers of diversification and centers of immigration.
The Qinghai‐Tibet Plateau (QTP) is considered a source region for colonization of adjacent areas such as the northern Palearctic. Using an ancestral area reconstruction approach on a phylogeny of 279 bird species, we suggest that faunal exchange between the QTP and adjacent regions was bidirectional through time and the QTP region has harbored both centers of diversification (for example of snowfinches) and centers of immigration.
Urbanization causes rapid changes in the landscape and land use, exerting a significant pressure on bird communities. The effect of urbanization on bird diversity has been widely investigated in many ...cities worldwide; however, our knowledge on urban bird communities from the eastern Mediterranean region is very scarce. In this context, we aimed to investigate the effect of the different land-cover types on bird species richness and abundance in a densely built coastal Mediterranean city (Patras, Greece) during the breeding and wintering seasons. We sampled the bird community in 90 randomly selected sites along an urbanization gradient. Open green spaces proved to be the most significant factor favouring bird diversity in both seasons. In winter, woody vegetation and impervious surfaces had a positive effect on species richness as well. The local bird community consisted of a large number of species associated with open and semi-open unmanaged green areas, 12 of which are Species of European Conservation Concern (SPECs) showing a declining trend in Europe. On the other hand, in winter the number of forest-dwellers increased significantly. Species richness was significantly higher in winter indicating that the urban environment provides important wintering grounds. Thus, management actions in cities with similar characteristics in the Mediterranean region should focus on the maintenance of open green spaces and woody vegetation patches to enhance bird diversity.
The post-2020 global biodiversity framework calls for a transformative change in food systems. Promoting agricultural multifunctionality is a viable approach to this sustainability transformation. ...The eastern Qinghai–Tibetan Plateau (QTP) is both one of the world’s largest livestock grazing systems and a hotspot of endemic birds in Asia. In this research, we aim to investigate the impact of livestock grazing on alpine bird assemblages at the local scale (alpha diversity) and their variation across the pastoral landscape (beta diversity). In the study area Nyanpo Yutse, we conducted surveys of 126 bird sample plots during two breeding seasons to acquire bird assemblage data. Meanwhile, we employed unmanned aerial vehicles to measure 2D and 3D habitat features within the 150-m radius. We investigated the key habitat variables driving the spatial distributions of both alpha and beta diversities of birds. Particularly, we partitioned beta diversity into its turnover and nestedness components and tested their patterns across sites of four levels of livestock grazing intensities (LGIs). Our results found no significant correlation between LGIs with species richness of birds, while 2D and 3D habitat complexity and built structure were positively correlated with alpha diversity (
p
< 0.05). At the landscape scale, pairwise LGI differences had no significant correlation (
p
> 0.05) with any pairwise beta diversity. The ordination plotting detected distinguished habitat preferences among 12 common birds and eight endemic birds. The multiple-site beta diversity of the 126 plots showed high species turnover (>0.871) where LGI was lower than 1.065 sheep units/ha, indicating the importance of moderate grazing for the conservation of diverse avian assemblages at the landscape scale. Our study demonstrated that extensive pastoralism is important for both maintaining the mosaic landscape and conserving avian biodiversity on the eastern QTP. We unveiled one of the ecological mechanisms through which synergies can be realized to support both agricultural production and biodiversity conservation in the Tibetan grazing system.
Tits (Aves: Paroidea) are distributed all over the northern hemisphere and tropical Africa, with highest species numbers in China and the Afrotropic. In order to find out if these areas are also the ...centers of origin, ancestral areas were reconstructed based on a molecular phylogeny. The Bayesian phylogenetic reconstruction was based on sequences for three mitochondrial genes and one nuclear gene. This phylogeny confirmed most of the results of previous studies, but also indicated that the Remizidae are not monophyletic and that, in particular, Cephalopyrus flammiceps is sister to the Paridae. Four approaches, parsimony- and likelihood-based ones, were applied to derive the areas occupied by ancestors of 75 % of the extant species for which sequence data were available. The common ancestor of the Paridae and the Remizidae inhabited tropical Africa and China. The Paridae, as well as most of its (sub)genera, originated in China, but Baeolophus originated in the Nearctic and Cyanistes in the Western Palearctic. Almost all biogeographic reconstruction methods produced similar results, but those which consider the likelihood of the transition from one area to another should be preferred.
Although urbanization poses one of the largest threats for biodiversity, only few studies have so far examined its impact in large Central European cities. Our study aimed at investigating the ...effects of urbanization on bird diversity using two methods to describe the urban environment. The first measure used the degree of sealing, portion of traffic infrastructure, number of floors of the tallest building at a site scale (100-m radius), and the distance from the city center, while the second one relied on land-cover data at a local scale (1000-m radius). We conducted bird surveys at 761 sites across Hamburg. Bird diversity was assessed as species richness, abundance, and Shannon index. Additionally, evenness was calculated. Both urbanization measures represented a rural-to-urban gradient and were negatively correlated with bird diversity as well as evenness. At the site scale, the degree of sealing had the strongest negative effect on bird diversity followed by the portion of traffic infrastructure and the tallest building. At the local scale, artificial surfaces proved to have the strongest negative effect, while agricultural areas and forests were positively associated with bird diversity. In general, models using the site scale for measuring urbanization showed higher associations with diversity. The results emphasize the importance of unsealed areas in the urban environment and of natural habitats in the periphery for bird diversity in Central European cities with millions of human inhabitants. Considering this for future city planning can help to preserve biodiversity in the urban environment, increase bird diversity in development areas, and thus improve living conditions for people.
Songs in passerine birds are important for territory defense and mating. Speciation rates in oscine passerines are so high, due to cultural evolution, that this bird lineage makes up half of the ...extant bird species. Leaf warblers are a speciose Old‐World passerine family of limited morphological differentiation, so that songs are even more important for species delimitation. We took 16 sonographic traits from song recordings of 80 leaf warbler taxa and correlated them with 15 potentially explanatory variables, pairwise, and in linear models. Based on a well‐resolved molecular phylogeny of the same taxa, all pairwise correlations were corrected for relatedness with phylogenetically independent contrasts and phylogenetic generalized linear models were used. We found a phylogenetic signal for most song traits, but a strong one only for the duration of the longest and of the shortest element, which are presumably inherited instead of learned. Body size of a leaf warbler species is a constraint on song frequencies independent of phylogeny. At least in this study, habitat density had only marginal impact on song features, which even disappeared through phylogenetic correction. Maybe most leaf warblers avoid the deterioration through sound propagation in dense vegetation by singing from exposed perches. Latitudinal (and longitudinal) extension of the breeding ranges was correlated with most song features, especially verse duration (longer polewards and westwards) and complexity (lower polewards). Climate niche or expansion history might explain these correlations. The number of different element types per verse decreases with elevation, possibly due to fewer resources and congeneric species at higher elevations.
Song recordings of 80 leaf warbler taxa were analysed and 16 sonographic traits correlated with 15 potentially explanatory variables, correcting for phylogenetic relationships. A strong phylogenetic signal was only found for two element traits. Frequencies were correlated with body size, many other traits with various biogeographic attributes.
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