Extinct Birds Research Articles

Avian telencephalon and cerebellum volumes can be accurately estimated from digital brain endocasts.

For studies of the evolution of vertebrate brain anatomy and potentially associated behaviours, reconstructions of digital brain endocasts from computed tomography scans have revolutionized our capacity to collect neuroanatomical data. However, measurements from digital endocasts must be validated as reflecting actual brain anatomy, which is difficult because the collection of soft tissue information through histology is laborious and time-consuming. In birds, the reliability of digital endocast measurements as volume proxies for the two largest brain regions-the telencephalon and cerebellum-remains to be validated despite their use as proxies, e.g. of cognitive performance or flight ability. We here use the largest dataset of histology and digital endocasts to date, including 136 species from 25 avian orders, to compare digital endocast surface area measurements with actual brain volumes of the telencephalon, cerebellum and whole-brain endocast. Using linear and phylogenetically informed regression analyses, we demonstrate that endocast surfaces are strongly correlated with their brain volume counterparts for both absolute and relative size. This provides empirical support for using endocast-derived cerebellar and telencephalic surface areas in existing and future studies of living and extinct birds, with potential to expand to the dinosaur-bird transition in the future.

Predicted bird extinctions shifts morphological diversity in a metropolitan region in Eastern Amazon

Predicted bird extinctions shifts morphological diversity in a metropolitan region in Eastern Amazon

Interaction rewiring can buffer the reduction of long‐distance dispersal of seeds when large birds go extinct: an allometric perspective

The loss of large frugivorous birds can impact their plant partners through loss of ecological services, like long‐distance dispersal of seeds. Yet, interaction rewiring, or the redistribution of interactions among remaining bird species, might help counteract the loss of long‐distance dispersal from large bird extinctions. Here, we tested if rewiring could mitigate loss of long‐distance dispersal and whether its effectiveness differed among plants with small and large fruits at different scales. We analyzed interaction data from eight Andean bird–plant seed dispersal networks, simulated extinction of large birds, allowed for lost interactions to rewire based on previous observed interactions, trait‐matching between birds and plants, and similarity in body sizes among birds (trait‐resemblance), and related changes in long‐distance dispersal to fruit‐size ratios. At the local scale, reduction in long‐distance dispersal varied among individual networks depending on whether rewiring occurred or not and the type of rewiring. At the regional scale, after aggregating results across local networks, reduction in long‐distance dispersal was between 20 and 40% for relatively small‐fruited plants (size ratio ≤ 0.25) and between 40 and 80% for relatively large‐fruited plants (size ratio ≥ 0.75) without interaction rewiring. However, with rewiring, reduction in long‐distance dispersal of smaller‐fruited plants was limited to 4% and between 4 and 10% for larger‐fruited plants. Thus, interaction rewiring can buffer losses in ecological functions, such as long‐distance dispersal, in response to large bird extinction, although relatively large‐fruited plants remain more vulnerable than smaller‐fruited plants.

Insights into Argentavis magnificens (Aves, Teratornithidae) lifestyle based on neuroanatomy.

Teratornithidae is an extinct bird family, likely related to Cathartidae, known exclusively from the Americas. They were once thought to be scavengers, but recent theories suggest they were opportunistic or piscivorous birds capable of swallowing prey whole. The most notable species, Argentavis magnificens, had a wingspan of 6 to 8 m and weighed 70 to 80 kg. In order to infer paleobiological aspects of this bird, its endocast (as a proxy for brain morphology), reconstructed from computed tomography scans of the holotype skull, is here described and compared to that of other bird species of zoophagous feeding habits with different flight styles. The brain of Argentavis presents a general appearance similar to that of Cathartidae, being dorsoventrally flattened and anteroposteriorly elongated, with small optic lobes in relation to the total encephalic surface. The estimated volume of the bulbi olfactorii is very similar to that of the Andean Condor Vultur gryphus. The main difference observed with Cathartidae is the marked development of the eminentiae sagittales present in Argentavis (structures closely related to the perception of visual information), which are more similar to those of the Accipitriformes and Falconiformes analyzed. The results obtained here suggest that Argentavis was a scavenger or even maybe a kleptoparasitic bird, relying more on vision than on smell (similar to that observed in the Andean Condor). Furthermore, the inner ear and flocculi exhibit characteristics similar to birds without acrobatic flight, indicating that Argentavis had a soaring flight and inhabited open areas without much vegetation.

Land Use and Climate Change Accelerate the Loss of Habitat and Ecological Corridor to Reeves's Pheasant (Syrmaticus reevesii) in China.

Human activity and climate change are widely considered to be primarily responsible for the extinction of Galliformes birds. Due to a decline in population, the Reeves's pheasant (Syrmaticus reevesii), a member of the Galliformes family, was recently elevated to first-class national protected status in China. However, determining the causal factors of their extinction and carrying out protection measures appear to be challenging owing to a lack of long-term data with high spatial and temporal resolutions. Here, based on a national field survey, we used habitat suitability models and integrated data on geographical environment, road development, land use, and climate change to predict the potential changes in the distribution and connectivity of the habitat of Reeves's pheasant from 1995 to 2050. Furthermore, ecological corridors were identified using the minimum cumulative resistance (MCR) model. The prioritized areas for habitat restoration were determined by integrating the importance indices of ecological sources and corridors. Our results indicated that both land use and climate change were linked to the increased habitat loss for the Reeves's pheasant. In more recent decades, road construction and land use changes have been linked to a rise in habitat loss, and future climate change has been predicted to cause the habitat to become even more fragmented and lose 89.58% of its total area. The ecological corridor for Reeves's pheasant will continue to decline by 88.55%. To counteract the negative effects of human activity and climate change on the survivorship of Reeves's pheasant, we recommend taking immediate actions, including bolstering cooperation among provincial governments, restoring habitats, and creating ecological corridors among important habitats.

AVOTREX: A Global Dataset of Extinct Birds and Their Traits

ABSTRACTMotivationHuman activities have been reshaping the natural world for tens of thousands of years, leading to the extinction of hundreds of bird species. Past research has provided evidence of extinction selectivity towards certain groups of species, but trait information is lacking for the majority of clades, especially for prehistoric extinctions identified only through subfossil remains. This incomplete knowledge potentially obscures the structure of natural communities, undermining our ability to infer changes in biodiversity across space and time, including trends in functional and phylogenetic diversity. Biases in currently available trait data also limit our ability to identify drivers and processes of extinction. Here we present AVOTREX, an open‐access database of species traits for all birds known to have gone extinct in the last 130,000 years. This database provides detailed morphological information for 610 extinct species, along with a pipeline to build phylogenetic trees that include these extinct species.Main Types of Variables ContainedFor each extinct bird species, we provide information on the taxonomy, geographic location, and period of extinction. We also present data on island endemicity, flight ability, and body mass, as well as standard measurements of external (matching the AVONET database of extant birds) and skeletal morphology from museum specimens where available. To ensure comprehensive morphological data coverage, we estimate all missing morphological measurements using a data imputation technique based on machine learning. Finally, we provide an R package to graft all extinct species onto a global phylogeny of extant species (BirdTree).Spatial Location and GrainGlobal.Time Period and GrainAll known globally extinct bird species from 130,000 years ago up until 2024.Major Taxa and Level of MeasurementBirds (Class Aves), species level.Software FormatSpreadsheets (.csv) stored in Dryad.

A New Species of the Feather Mite Genus Grallolichus Gaud, 1960 (Acariformes: Pterolichidae): First Report of a Commensal Mite Specific to the Sungrebe (Heliornis fulica).

Feather mites of finfoots (Heliornithidae), a small gruiform family, are poorly and partly erroneously recognized. Grallolichus heliornisi sp. n. (Astigmata: Pterolichidae) is here described from the sungrebe Heliornis fulica as the first representative of the genus commonly found on close relatives of finfoots, Rallidae and Sarothuridae. This species belongs to the species group having ornamented dorsal shields and is morphologically most close to G. proctogamus inhabiting Eurasian coot (Fulica atra). Males of the new species differ from G. proctogamus mainly by the shape of opisthosomal lobes (triangular vs. rounded) and the aedeagus form (parallel sided vs. tapering distally). Females differ mainly by the shape of supranal concavity (open anteriorly vs. closed) and location of setae h1 in relation to supranal concavity (lateral vs. anterior). A key to known species of the genus Grallolichus is provided. The morphological analysis and descriptive characterization of this species, like much of the approximately 2500 feather mite species described to date, were based on mummified mite material preserved in 19th-century old museum bird specimens. These often-forgotten collections are the only source for the analysis of the acarofauna of many rare, unavailable wild or even extinct bird taxa.

An account of the natural history and exploitation of the great auk (Pinguinus impennis) in ‘Histoire des pesches’, an illustrated eighteenth-century manuscript

The hunting of the great auk ( Pinguinus impennis), which led to its extinction in the mid-nineteenth century, is well documented. However, the discovery of archives providing new details on this species is a rare event. A manuscript dealing with seabirds and their ‘fishing’, written in 1720–1722 by François Le Masson du Parc (1671–1741), an attaché for the Normandy maritime administration, was acquired in 2019 from an auction house. This unpublished and unstudied manuscript comprises the sixth and final volume of the ‘Histoire des pesches’. As part of a national policy to regulate French maritime fisheries, Le Masson du Parc completed the description of marine resources and fisheries in his ‘Histoire des pesches’ which was abundantly illustrated by Pierre Le Chevalier (1688–after 1763). However, this monumental work was never published and the manuscripts were dispersed after the author's death. The section recently purchased provides valuable information on the spatiotemporal evolution of many populations of North Atlantic seabirds, including the great auk, in a context of anthropogenic pressures. This species is named using several hitherto unknown Latin and vernacular names of great importance for the exploration or reinterpretation of archives. It is mentioned as common and one of the most popular birds consumed by cod fishermen on the banks of Newfoundland and that it was caught using baited hooks from boats. The text is accompanied by two illustrations, including a life drawing of three great auks, which are among the oldest known illustrations of the species. These 300-year-old archives constitute a valuable testimony for the historical ecology of this iconic, extinct bird.

Overlooked Bird Extinctions in Semideciduous Atlantic Forests.

The semideciduous forest is a prominent yet highly degraded phytophysiognomy within the Atlantic Forest. Historically, bird species inhabiting these forests occurred throughout central and western São Paulo state, south-eastern Brazil, until the mid-20th century. Many of these species have not been observed again or are nearing extinction within the state's inland forest fragments. This study reviews and compares historical and recent ornithological records, using museum specimens, literature, citizen science and recent field surveys to understand these species' current lack of records. In the early 20th century, extensive deforestation occurred statewide, resulting in the current forest fragments, which are currently in various stages of regeneration, conservation and isolation. Many of these fragments lack the specific habitats some species require, or they have not been recolonised due to insufficient connectivity with other forest fragments where these species still exist (particularly in the eastern Atlantic Forest). The non-detection of forest species in semideciduous forest fragments strongly suggests an unprecedented and largely unnoticed extinction scale. This pattern of defaunation, as predicted 30 years ago, may be prevalent across numerous Semideciduous Atlantic Forests in Brazil.

Influence of coronavirus disease 2019 on attitudes toward forest biodiversity and nature conservation

The goal of this study is to better understand public perceptions of biodiversity loss, with a focus on the connections between deforestation and the eventual extinction of plants, animals, and birds. In Malaysia, a questionnaire study covering five variables – deforestation, the extinction of mammals, birds, and plants – as well as the moderating effect of coronavirus disease 2019 (COVID-19) on public attitudes toward biodiversity loss – was conducted. Using online survey methods, 505 valid responses in total were acquired, and SMART-PLS was used for data analysis. Deforestation (the independent variable) is significantly and positively correlated with the extinction of birds, mammals, and plants, respectively. The study also demonstrates how COVID-19 moderates animal extinction and its impact on public perceptions of biodiversity protection. However, statistical study shows that popular perceptions of biodiversity protection are not significantly impacted by the loss of birds or plants. This study adds to the body of knowledge on the importance of public attitudes in reducing environmental degradation by providing a thorough analysis of popular attitudes toward biodiversity protection. The research has important ramifications for governments and organizations working to promote environmentally friendly behaviors, improve ecosystem sustainability, and encourage environmentally friendly organizations.

Endemic and threatened birds as surrogates for identifying conservation priority areas and ecological corridors in the America’s most endangered habitat

Investigating multi-taxa macroecological patterns can provide critical insights for spatial conservation planning and landscape management across biodiversity hotspots. The Pernambuco Endemism Center (PEC) is a biogeographic region of the Brazilian Atlantic Forest known to harbor the most threatened habitats in the Americas and a considerable number of recent bird extinctions. Here, we modeled the distribution of 30 threatened forest-dependent birds, 29 of which endemic to the PEC, to reveal key habitats/resources for their survival, identify conservation priority areas, and design ecological corridors. We found variations in the responses of the taxa to landscape characteristics when we addressed these organisms separately and when we grouped them by conservation status. Overall, the environmental variables related to forest quality (e.g., distance to large fragments, distance to the forest edge, percentage of tree cover, percentage of older forests) were important predictors of habitat suitability for the regional threatened avifauna. Additionally, we revealed forest fragments of high ecological importance for the PEC’s threatened birds, and we propose the creation of the Pernambuco Endemism Center Restoration Arc (PEC-ARC) that may maximize the investments in conservation and guarantee the connectivity of crucial areas for long-term species survival.

Identification and Conservation Status of Birds Traded in Bird Shops in Kuranji District, Nanggalo District, East Padang District, South Padang District, and Lubuk Begalung District, West Sumatra

Indonesia is a country with the highest diversity in the world. One of Indonesia's diversity is birds. Birds have many roles in maintaining the balance of nature. However, as birds become more popular every year, many birds are hunted and traded freely. This has an impact on the natural imbalance caused by the decline in bird populations and even the extinction of birds. The purpose of this study is to identify the species and conservation status of birds traded in Padang City, West Sumatra. This study is a descriptive study with a field survey method in several bird shops spread across several sub-districts in Padang City, West Sumatra. The results of the identification of the conservation status of birds traded in the city of Padang, West Sumatra used the IUCN red list website. Based on the data, as many as 25 out of 34 species of birds that have been identified have the Least Consern conservation status.

Massive Bird Nest Losses: A Neglected Threat for Passerine Birds in Atlantic Forest Fragments from the Pernambuco Endemism Center

Understanding the mechanisms by which tropical forest fragmentation can affect the persistence of species and populations is of scientific and practical interest. However, nest survival has been one the least addressed of the potentially harmful effects associated with habitat fragmentation, and studies involving nest predator’s identification are still underdeveloped. The Pernambuco Endemism Center (PEC) is the part of the Atlantic Forest located north of the São Francisco River, in northeastern Brazil, where large forest tracts no longer exist and a wave of bird extinctions has occurred recently. Here, we investigated the nest survival of forest understory birds from three PEC fragments (690, 979, and 1036 ha), and we used infra-red camera traps for predators’ identification. Overall, the apparent nest survival was 15.5%, and nest-day-based survival probability for the four more representative species (including two endemic and threatened taxa) were 2.6, 4.4, 6.9, and 18.9%, being 2.7 to 8.5 times smaller than populations or related taxa from the Atlantic Forest of southeastern Brazil. Predators were marmosets (25%), opossums (25%), tegu (19.4%), coati (16.7%), snakes (8.3%), and hawks (5.5%). Jackknife2 model-predicted nest predator’s richness was 20.7 (SD = 1.6). We reinforce the evidence that nest predation associated with fragmentation can affect negatively the bird populations from tropical forests.

The end of the aukThe Last of Its Kind: The Search for the Great Auk and the Discovery of Extinction Gísli Pálsson Princeton University Press, 2024. 328 pp.

An anthropologist recounts how a pair of 19th-century naturalists traced an elusive bird's extinction in real time.

Potential extinction cascades in a desert ecosystem: Linking food web interactions to community viability.

Desert communities are threatened with species loss due to climate change, and their resistance to such losses is unknown. We constructed a food web of the Mojave Desert terrestrial community (300 nodes, 4080 edges) to empirically examine the potential cascading effects of bird extinctions on this desert network, compared to losses of mammals and lizards. We focused on birds because they are already disappearing from the Mojave, and their relative thermal vulnerabilities are known. We quantified bottom-up secondary extinctions and evaluated the relative resistance of the community to losses of each vertebrate group. The impact of random bird species loss was relatively low compared to the consequences of mammal (causing the greatest number of cascading losses) or reptile loss, and birds were relatively less likely to be in trophic positions that could drive top-down effects in apparent competition and tri-tropic cascade motifs. An avian extinction cascade with year-long resident birds caused more secondary extinctions than the cascade involving all bird species for randomized ordered extinctions. Notably, we also found that relatively high interconnectivity among avian species has formed a subweb, enhancing network resistance to bird losses.

Environmental and geographical factors influence the occurrence and abundance of the southern house mosquito, Culex quinquefasciatus, in Hawai‘i

Hawaiian honeycreepers, a group of endemic Hawaiian forest birds, are being threatened by avian malaria, a non-native disease that is driving honeycreepers populations to extinction. Avian malaria is caused by the parasite Plasmodium relictum, which is transmitted by the invasive mosquito Culex quinquefasciatus. Environmental and geographical factors play an important role in shaping mosquito-borne disease transmission dynamics through their influence on the distribution and abundance of mosquitoes. We assessed the effects of environmental (temperature, precipitation), geographic (site, elevation, distance to anthropogenic features), and trap type (CDC light trap, CDC gravid trap) factors on mosquito occurrence and abundance. Occurrence was analyzed using classification and regression tree models (CART) and generalized linear models (GLM); abundance (count data) was analyzed using generalized linear mixed models (GLMMs). Models predicted highest mosquito occurrence at mid-elevation sites and between July and November. Occurrence increased with temperature and precipitation up to 580 mm. For abundance, the best model was a zero-inflated negative-binomial model that indicated higher abundance of mosquitoes at mid-elevation sites and peak abundance between August and October. Estimation of occurrence and abundance as well as understanding the factors that influence them are key for mosquito control, which may reduce the risk of forest bird extinction.

Extinct Australian birds: numbers, characteristics, lessons and prospects

ABSTRACT Since European colonisation of Australia in 1788, nine Australian bird species (1.2% of the Australian total) have become extinct, along with 22 subspecies (of 16 species). Consistent with global patterns, Australia’s island endemic birds have been particularly susceptible, comprising eight of the nine species’ extinctions (38% of the bird species endemic to islands smaller than Tasmania), and 13 of the 22 subspecies’ extinctions. The extinction of only one bird species (Paradise Parrot Psephotellus pulcherrimus) from the Australian mainland contrasts with the far higher rate of extinctions of Australian mammals (27 of 312 species that occurred on the Australian mainland), and is comparable with the rate of extinctions of birds on the mainland of other continents over this period. Extinctions of Australian birds were caused mainly by introduced predators (especially for island taxa), habitat degradation, and hunting (for some island taxa). The timing of some extinctions is uncertain, but the first bird extinction subsequent to European colonisation was the loss of the flightless White Gallinule Porphyrio albus from Lord Howe Island over the period 1788–1790. Extinctions have occurred in most decades since then, with the most recent being for Norfolk Island’s White-chested White-eye Zosterops albogularis in the decade 2000–2009. Environmental legislation, an extensive conservation reserve system, and dedicated conservation management efforts have prevented some extinctions. However, local extirpations continue, many threatened species continue to decline and, without an increase in conservation efforts, the rate of extinctions is likely to increase, mainly due to the direct and compounding impacts of climate change.

Understanding the Effect of Climate Change on Migratory Birds: A Review

Climate change is being referred to as a global plague and has significant negative consequences on the world’s economic, social, and ecological systems. Extreme weather consequences like drought, floods, and heat waves have had unprecedented occurrences and have had substantial effects on animals and plants. Climate change significantly influences animal phenologies, such as bird arrival and egg-laying times. As a result of these present and future climate change impacts, species interactions with their local environment are anticipated to change, resulting in changes in population size, range extent, and extinction rates. The current review discusses the effect of climate changes on migratory birds and concludes that climate change is one of the most serious dangers to world ecological systems, as indicated by the numerous ecological impacts imposed by changing climate on migratory birds. Climate change significantly affects breeding strategies, migration, distribution, latitudinal or altitudinal shift, community structure change, morphological change, and elimination or extinction of migratory birds. The current review attempts to communicate research and advances in the effect of climate change on migratory birds to different actors in society, including researchers, conservationists, practitioners, and policymakers.

Remarkable insights into modern bird origins from the Maastrichtian type area (north-east Belgium, south-east Netherlands)

Abstract For centuries, fossils from the Maastrichtian type locality and adjacent quarries have provided key evidence of vertebrate diversity during the latest Cretaceous, yet until recently the Maastrichtian type area had revealed no important insights into the evolutionary history of birds, one of the world’s most conspicuous groups of extant tetrapods. With the benefit of high-resolution micro-CT scanning, two important avian fossils from the Maastrichtian type area have now been examined in detail, offering profound, complementary insights into the evolutionary history of birds. The holotype specimens of these new taxa, Janavis finalidens Benito, Kuo, Widrig, Jagt and Field, 2022, and Asteriornis maastrichtensis Field, Benito, Chen, Jagt and Ksepka, 2020, were originally collected in the late 1990s, but were only investigated in detail more than twenty years later. Collectively, Janavis and Asteriornis provide some of the best evidence worldwide regarding the factors that influenced stem bird extinction and crown bird survivorship through the Cretaceous-Palaeogene transition, as well as insights into the origins of key anatomical features of birds such as an extensively pneumatised postcranial skeleton, a kinetic palate, and a toothless beak. Asteriornis also provides scarce evidence of a Cretaceous-aged divergence time calibration within the avian crown group, while together, Janavis and Asteriornis constitute the only documented co-occurrence of crown birds and non-neornithine avialans. Here, we review key insights into avian evolutionary history provided by these discoveries from the Maastrichtian stratotype, document undescribed and newly discovered Maastrichtian fossils potentially attributable to Avialae and provide the first histological data for the holotype of Asteriornis, illustrating its skeletal maturity at the time of its death.

Undiscovered bird extinctions obscure the true magnitude of human-driven extinction waves

Birds are among the best-studied animal groups, but their prehistoric diversity is poorly known due to low fossilization potential. Hence, while many human-driven bird extinctions (i.e., extinctions caused directly by human activities such as hunting, as well as indirectly through human-associated impacts such as land use change, fire, and the introduction of invasive species) have been recorded, the true number is likely much larger. Here, by combining recorded extinctions with model estimates based on the completeness of the fossil record, we suggest that at least ~1300–1500 bird species (~12% of the total) have gone extinct since the Late Pleistocene, with 55% of these extinctions undiscovered (not yet discovered or left no trace). We estimate that the Pacific accounts for 61% of total bird extinctions. Bird extinction rate varied through time with an intense episode ~1300 CE, which likely represents the largest human-driven vertebrate extinction wave ever, and a rate 80 (60–95) times the background extinction rate. Thus, humans have already driven more than one in nine bird species to extinction, with likely severe, and potentially irreversible, ecological and evolutionary consequences.