Estación Biológica de Doñana - CSIC

María Belén Cañuelo Jurado

gestor — Mon, 08 May 2023 11:40:42 +0000

María Belén

Cañuelo Jurado

mariabelen@ebd.csic.es

Asturias alberga una gran diversidad de cigarras hasta ahora desconocida y una posible nueva especie

77176912K — Fri, 10 Jul 2026 07:20:11 +0000

10 July 2026

The northern Spanish region of Asturias harbours a remarkable diversity of cicadas, including a potentially new species

A study coordinated by the Doñana Biological Station and conducted between 2023 and 2025 has revealed an unexpectedly rich diversity of cicadas across Asturias in northern Spain. The researchers also identified a population whose acoustic and genetic characteristics do not match those of any previously known European species, suggesting it may represent a species new to science.

Cicadetta in Lena, Asturias. Credit: Saúl Rodríguez.

A study coordinated by the Doñana Biological Station (EBD-CSIC) demonstrates that the Atlantic climate of northern Iberia does not prevent the presence of diverse cicada populations, traditionally associated with warm Mediterranean regions. The study, published in the Journal of Insect Science, identifies four cicada taxa in Asturias: Cicada orni, Tibicina quadrisignata, Tettigettalna argentata and Cicadetta sp. In addition, the researchers detected a population of Cicadetta whose acoustic and genetic characteristics do not match any previously known European species.

“The results suggest that it could be a species that has not yet been described, although additional taxonomic studies will be necessary to formally confirm this,” says Jairo Robla, researcher at the Doñana Biological Station and first author of the study.

Since Atlantic environments, characterized by high humidity and mild summers, were considered unsuitable for cicadas, these insects had never been studied in northern Iberia. As a result, this research provides the first comprehensive characterization of their distribution, habitat, behaviour, songs and genetic diversity in Asturias.

A novel approach

The study was conducted over three fieldwork seasons between 2023 and 2025 across different areas of Asturias. During the surveys, males were located by their songs, the coordinates of the populations were recorded, and information was collected on habitat, vegetation, altitude, temperature and the behaviour of the specimens.

Cicada songs, which are essential for distinguishing species, were recorded and analysed using sonograms. In addition, several specimens were collected for morphological identification and subsequently deposited in the Scientific Collections of the Doñana Biological Station. Finally, distribution models based on climatic and topographic variables were developed to identify the areas of Asturias with the most suitable conditions for each species, helping to guide future surveys. “The combination of ecological, acoustic, morphological and molecular information is particularly innovative, as this kind of integrative approach is not usually applied,” highlights Robla.

Further research ahead

Besides considerably expanding knowledge of insect biodiversity in northern Iberia, the results show that Atlantic environments can harbour unique and potentially unknown lineages. Furthermore, the data indicate that climate change and wildfires may affect different species in different ways. While some thermophilic cicadas may expand their distribution, other populations adapted to cooler and more humid environments could be negatively affected. The distribution models can be used to direct future surveys towards areas with a higher probability of harbouring previously unknown populations or even new species. This will help complete the inventory of cicadas in Asturias and determine whether other geographically nearby species are also present.

“One of the main future research lines will be to study the Cicadetta population in greater detail, comparing it with European populations through broader morphological, acoustic and genomic analyses. If its uniqueness is confirmed, this work could ultimately lead to the formal description of a new species,” concludes Robla.

Reference

Robla, J. Nunes, V. L., Orois, I., Cabana, M., Rodríguez-Pérez, J., Sánchez, O. & Rodríguez, S. R. (2026). Echoes from northern Iberia: distribution, ecology, genetics and identification of Asturian cicadas (Hemiptera: Cicadidae). Journal of Insect Science. https://doi.org/10.1093/jisesa/ieag065

El canto, más que el color, ayuda a evitar la hibridación entre aves

77176912K — Thu, 09 Jul 2026 12:20:29 +0000

09 July 2026

Song, more than color, helps prevent hybridization in birds

A new study conducted by researchers of the Doñana Biological Station and published in Biology Letters shows that differences in song between species are more closely associated with reduced hybridization than differences in plumage coloration.

Yellow-rumped Warbler (Setophaga coronata), one of the bird species with the highest rates of hybridization. Creative Commons

In the wild, correctly identifying a potential mate from the same species can be crucial. In many animals—and especially in birds—this recognition relies on signals such as song, plumage coloration, or courtship behaviour. But which of these signals matters most in preventing interbreeding between different species? A new study by the Doñana Biological Station (EBD-CSIC), published in Biology Letters, suggests that, in birds, song may play a more decisive role than plumage coloration in limiting hybridization between species. The study examined whether differences in acoustic and visual signals between species with their propensity to hybridize.

Hybridization—the mating of individuals from different species—is far more common than traditionally believed and continues to fascinate evolutionary biologists. Although it can generate genetic variation and, in some cases, contribute to the evolution of new forms, it can also carry significant costs. If hybrids have lower survival or reproductive success, natural selection is expected to favour mechanisms that help species recognize one another correctly and avoid “mistaken” matings, thereby increasing their overall fitness.

In birds, two of the most prominent communication channels are song and colour. Song plays a direct role in mate attraction, territory defence, and species recognition. Plumage coloration, meanwhile, can function as a visual signal during courtship and social interactions. However, the relative importance of these two signals in reducing hybridization between species had never been assessed on a broad scale.

To investigate this question, the research team compared closely related bird species and evaluated the extent to which differences in their acoustic and visual signals were associated with the number of documented hybrid combinations.

“The logic is straightforward: if two species are very similar in their mating signals, recognition errors are more likely to occur. Conversely, if their signals differ greatly, hybridization should be less likely,” says Vicente García-Navas, the lead author of the study.

The findings point to a particularly important role for song. Species with more divergent songs were less likely to hybridize, suggesting that acoustic signals may act as a pre-mating barrier that reduces the likelihood of interbreeding. By contrast, differences in plumage coloration showed no clear relationship with hybridization. This does not mean that colour is unimportant in bird communication. In many species, plumage plays essential roles in sexual selection, social recognition, and competition between individuals. However, the study indicates that, at a broad evolutionary scale, song may be a more effective signal—or one more directly involved in maintaining reproductive isolation between species.

"One possible explanation is that song is a highly specific and flexible signal, capable of conveying detailed information about species identity. Moreover, in many songbirds, acoustic communication takes place precisely during courtship and territorial defence, where recognition errors can have direct reproductive consequences," explains García-Navas. "Plumage colour, on the other hand, is shaped by multiple selective pressures—including camouflage, sexual selection, the light environment, and predation—which may weaken its direct relationship with hybridization."

The study addresses a longstanding question in evolutionary biology: how species remain distinct despite living in close contact and having opportunities to interbreed. Its findings support the idea that communication signals not only attract mates but also help preserve the boundaries between species.

Reference

García-Navas, V., Ortego, J. (2026) Song but not colour divergence constrains hybridization in birds. Biology Letters, 122: 20260237 https://doi.org/10.1098/rsbl.2026.0237

Reducir un 10% la mortalidad del lobo ibérico permitiría mejorar su estado de conservación

77176912K — Tue, 07 Jul 2026 07:28:16 +0000

07 July 2026

Reducing the mortality of Iberian wolf by 10% would help improve its conservation status

A study led by the Doñana Biological Station (EBD-CSIC) concludes that the high mortality of Iberian wolf explains why their population has remained stagnant in recent decades. Reducing the mortality rate of the Iberian wolf is key to improve the conservation status of the species, classified as “Vulnerable” in Spain and “In danger” in Portugal by the UICN

The study reveals that reducing mortality of Iberian wolves living in family group by 10% would result in larger groups, higher reproductive success, and longer dispersal distances. Photo: Alberto Fernández Gil / EBD-CSIC

A research team led by the Doñana Biological Station (EBD-CSIC) has shown in a study on wolf demography across the Iberian Peninsula that wolf mortality explains why the species' range has barely expanded over recent decades despite the availability of suitable habitat for expansion. The study concludes that reducing mortality would be key to promoting population recovery and improving the conservation status of this population, which the IUCN classifies as "Vulnerable" in Spain and "Endangered" in Portugal.

Over the past few decades, wolf populations across Europe and North America have recovered part of their historical range and expanded into highly human-modified landscapes such as Germany, Denmark, the Netherlands and France. However, official data from Portugal and the Spanish autonomous communities where wolves are present show that this has not been the case for the Iberian wolf. Despite the availability of extensive suitable habitat, the population has shown little change in its distribution over recent decades. This apparent contradiction prompted the Doñana Biological Station research team to investigate the factors limiting its expansion.

"Over the past few decades, the distribution of wolves across the Iberian Peninsula has remained largely unchanged, apart from small areas that have been colonized and others where the species has disappeared, including the extinction of the Sierra Morena population. Meanwhile other European wolf populations expanded very rapidly during the same period," explains Ana Morales, postdoctoral researcher and lead author of the study. "We asked a simple question: what factors could explain this pattern and be preventing the species' recovery in Spain and Portugal?"

To answer this question, the team developed a highly detailed demographic model capable of reproducing changes in the Iberian wolf population between 1991 and 2021, fitting the model's demographic parameters to official data on range distribution and population size estimates collected during that period. Once the model was validated, the researchers examined how reducing mortality among different categories of individuals would affect the population's future.

The results showed that although dispersing wolves are responsible for colonizing new territories, reducing mortality only among dispersers had little effect on population dynamics. By contrast, reducing mortality among wolves living in family packs by just 10% was enough to improve the population's conservation status.

The model showed that with this modest 10% reduction in mortality of resident wolves, groups became larger, reproductive success increased, and straight-line dispersal distances rose from around 32 to more than 70 kilometres. As a result, the population could grow and expand to double its current range within approximately three decades. Based on the model, the team estimated that each year approximately one quarter of wolves living in family groups die, along with more than one third of dispersing individuals and more than half of all pups.

"The key point is that wolf groups are family units with a complex social structure, and the loss of these individuals triggers cascading effects that extend far beyond the death of isolated animals, especially when one of the breeding pair dies," explains researcher Eloy Revilla, co-author of the study. "So many vacancies and unoccupied territories are created that dispersing wolves tend to settle close to their birthplace instead of colonizing new areas."

Implications for Iberian wolf conservation

The study's findings are particularly relevant in the current context of changes to wolf protection status in Europe and Spain. In Spain, in 2021, the wolf was included in the Spanish List of Wild Species under Special Protection (LESRPE), which brought wolf hunting to an end throughout the country.

The research team compared the model's predictions with the results of Spain's most recent national wolf census. The census estimated 333 family packs for the 2021–2024 period, a figure comparable to the model's predictions for 2013–2021. This suggests that during those years the Iberian wolf population did not experience any significant improvement in its conservation status, consistent with the IUCN's most recent assessments.

Despite this, the species lost its protected status at the national level in Spain in 2025 following its removal from the LESRPE. "Our study warns that this legislative change could hinder population recovery if mortality returns to levels similar to those recorded up to 2021, and that effective legal protection together with stronger measures to prevent and combat illegal killing are essential tools for improving the conservation status of this population," explains Morales.

Beyond the Iberian case, the research team suggests that the situation observed on the peninsula could also occur in other expanding European wolf populations where mortality is increasing, such as those in France and Germany. This work could provide a valuable tool for assessing how different conservation and management strategies may influence the future of the Iberian population as well as other wolf populations.

The study also highlights an important limitation for wolf conservation: the lack of high-quality demographic data. Developing the model required integrating the available data on abundance and distribution collected in the field by different administrations using non-standardized methodologies that vary between authorities and even over time within the same administration. It also required estimating key parameters such as survival, reproduction and dispersal, for which direct data are extremely limited. This demonstrates the value of demographic models in complementing field monitoring, while also highlighting the need to improve and harmonize wolf monitoring programmes to provide more comprehensive and robust information.

Reference

Morales-González, A., Fernández-Gil, A., Quevedo, M., Kramer-Schadt, S., Paniw, M. & Revilla, E. (2026). Resident mortality determines grey wolf range dynamics. Journal of Applied Ecology, 63, e70465. https://besjournals.onlinelibrary.wiley.com/doi/10.1111/1365-2664.70465

Una señal “caliente” para mantener la cabeza fría: el cerebro de las crías de ave se prepara para el calor antes de nacer

77176912K — Thu, 02 Jul 2026 12:48:38 +0000

02 July 2026

A “Heat Call” that keeps a cool head: baby birds prepare for heat before they hatch

A study involving the Doñana Biological Station (EBD-CSIC) reveals that a specific call produced by parent birds alters gene expression in the brains of developing embryos, activating mechanisms associated with protection against high temperatures.

A new international study involving researchers from the Doñana Biological Station (EBD-CSIC) reveals that young birds begin preparing to cope with high temperatures even before they hatch. The research, carried out on the zebra finch (Taeniopygia guttata), shows that while still developing inside the egg, embryos respond to a specific call produced by their parents only during hot weather. Hearing this call activates a distinct set of genes from those triggered by other parental vocalisations, including genes involved in regulating blood flow and fluid balance, two processes that play a key role in cooling the brain.

“It is remarkable that sound alone, perceived from inside the egg, can alter how the brain functions,” says Mylene Mariette, researcher at the Doñana Biological Station.

To investigate this phenomenon, freshly laid eggs were removed from nests and incubated under optimal conditions in artificial incubators. At the same time, speakers built into the incubators played the “heat call” to one group of eggs and other parental calls to another. On the day before hatching, the embryos' brains were examined to determine which of the thousands of genes expressed in the brain had been activated or switched off.

This study builds on a decade of research led by Mariette demonstrating that the “heat call” prepares developing chicks to cope with high temperatures by modifying different aspects of their physiology and behaviour. However, this is the first study to examine the changes that this acoustic signal induces directly in the brain.

Initially, the research team expected to identify the common mechanism underlying all the previously observed changes. To do so, they focused specifically on the hypothalamus, a brain region that plays a central role in hormonal regulation and the detection of body temperature. Instead of orchestrating the body's preparation for heat, however, they discovered that the brain itself appears to be preparing to protect its own function.

The findings came as a surprise. “We expected to see major changes in the genes regulating hormonal functions, particularly those involved in stress responses, growth, metabolism and temperature regulation,” explains Julia Georges, lead author of the study. “At first, it was disappointing to find that those changes were only very modest,” she says.

The brain appears to protect itself

The real surprise came when the researchers discovered that the strongest response was not related to hormonal regulation but rather to genes involved in muscle contraction and cytoskeletal dynamics. These genes were expressed primarily in the muscle cells surrounding blood vessels in the brain and in cells responsible for regulating the movement of fluid into the brain.

The results showed that chicks exposed to the “heat call” developed greater flexibility in the blood-brain barrier, the structure that controls the exchange of substances between the bloodstream and the brain. This feature is also observed under conditions of extreme heat. However, in this study the changes occurred solely in response to the acoustic signal, without the embryos ever being exposed to high temperatures.

“It is remarkable that both heat itself and the ‘heat call’ affect the same trait in the same direction,” says Mariette. “The cells that make up the blood-brain barrier account for only about 2% of all brain cells, the vast majority being neurons and glial cells. Even so, the effect was very clear.”

The research team will continue investigating what these changes in gene expression mean for an individual's resilience to heat stress.

The study was published in the Journal of Experimental Biology and is the first paper arising from the PhD thesis of first author Prakrit Subba.

Reference

Subba P, Mariette MM, Palios KA, Emmerson MG, Versace E, Buchanan KL, Clayton DF & George JM. “Prenatal acoustic communication triggers adaptive vascular programming in the developing avian brain”. Journal of Experimental Biology. 252287. https://doi.org/10.1242/jeb.252287

La ICTS-Doñana lanza dos nuevos portales web para el acceso público a sus datos hidrometeorológicos históricos y en tiempo real

outreach@ebd.csic.es — Thu, 02 Jul 2026 10:02:32 +0000

02 July 2026

ICTS-Doñana launches two new web portals providing public access to historical and real-time hydrometeorological data

The two platforms allow users to explore, visualise and download high-resolution environmental data. Hydromet provides near real-time hydrometeorological information from the Doñana marshes at five-minute intervals, while Meteo Palacio offers access to a historical meteorological dataset spanning more than 45 years of continuous observations

Hydrometeorological Tower at Honduras del Burro (Doñana National Park, Huelva). Photo: J. Manuel Vidal-Cordero / ICTS-Doñana, EBD-CSIC

The ICTS-Doñana, Singular Scientific and Technical Infrastructures operated by the Doñana Biological Station (EBD-CSIC), today launched two new open-access web portals providing public access to environmental data from Doñana. The first, Hidromet, focuses on monitoring the hydrology and meteorology of the Doñana National Park marshes. The second, Meteo Palacio, provides access to one of the longest-running meteorological records in the protected area, with continuous observations dating back to 1978. Together, these platforms make high-resolution environmental data available to researchers, land managers, the media and the general public, providing essential information for understanding how this internationally important wetland functions and responds to global environmental change.

“Having detailed, open-access data helps us better understand Doñana’s ecosystems and monitor how they respond to environmental change. It also supports scientific research while making this information more accessible to society,” says Eduardo Escobar, web developer for the ICTS-Doñana Data and Metadata Team.

A unique infrastructure for environmental monitoring in Doñana

The Hydromet portal integrates data collected through a network of automated monitoring stations distributed across the Doñana Biological Reserve, recording key environmental variables such as air temperature, rainfall, solar radiation, wind, humidity and water level. With a temporal resolution of just five minutes, these observations allow researchers to analyse in great detail the hydrological and climatic processes that drive one of Europe's most valuable natural ecosystems. Data are collected by automatic sensors and dataloggers installed at strategic locations throughout the reserve, transmitting information continuously with an approximate 24-hour latency.

The platform provides access to both raw data and aggregated time series at hourly, daily and monthly intervals, allowing users to visualise interactive graphs and compare monitoring stations through an intuitive map-based interface. Users can also download the data in open CSV format together with their associated metadata, or access them through a REST API, facilitating their reuse in scientific research, applications and analytical tools.

This system enables the monitoring of key environmental processes such as the seasonal flooding cycle of the marshes, microclimatic dynamics and extreme weather events, providing a robust foundation for research in ecology, hydrology, climate change and protected area management.

The platform is complemented by Meteo Palacio, a second web portal providing access to the historical records of the Doñana Palace meteorological station, with more than 45 years of continuous observations since 1978. This is the most comprehensive long-term meteorological dataset available for Doñana and its surrounding area, containing temperature and precipitation records collected through systematic manual observations. It represents an exceptional resource for analysing long-term climate trends within the protected area.

Manual meteorological station at Doñana Palace (Doñana Biological Reserve, Huelva). Photo: J. Manuel Vidal-Cordero

Beyond their scientific value, these web portals provide an objective and up-to-date source of information for tracking issues of public interest, including the flooding status of the marshes throughout the year, droughts, floods, heatwaves and changing rainfall patterns. Open access to these data also enhances environmental communication about the protected area and brings knowledge of one of UNESCO's Biosphere Reserves closer to the public.

Open science serving research and society

All data are freely available under a Creative Commons CC BY 4.0 licence, allowing them to be reused for scientific, educational or commercial purposes, provided the source is acknowledged. This reflects the commitment of the Doñana Biological Station (EBD-CSIC) to open science and the FAIR principles, ensuring that data are Findable, Accessible, Interoperable and Reusable.

The project forms part of the monitoring, scientific assessment and knowledge enhancement measures included in the Doñana Action Framework, coordinated by the Commissioner for the Water Cycle and Ecosystem Restoration of Spain's Ministry for the Ecological Transition and the Demographic Challenge. Development of the platform began under the PENELOPE project, funded through the NextGenerationEU programme and Spain's Recovery, Transformation and Resilience Plan, with the aim of increasing the value and accessibility of the extensive environmental datasets generated by ICTS-Doñana through public funding.

Hydromet interface, the new public web portal providing access to hydrometeorological data collected by the network of automated monitoring stations across the Doñana Biological Reserve.

About ICTS-Doñana

The Doñana environmental monitoring databases maintained by EBD-CSIC are part of the ICTS Doñana Biological Reserve, a Unique Scientific and Technical Infrastructure operated by the Doñana Biological Station (EBD-CSIC). ICTS-Doñana is Europe's largest field laboratory and an internationally recognised centre for research on biodiversity, ecology and the impacts of global change. It provides accommodation, specialised equipment, laboratories, as well as technical and logistical support for the scientific community. Access to the ICTS infrastructure is granted through projects approved by an independent Access Committee, and ICTS-Doñana forms part of Spain's national network of Unique Scientific and Technical Infrastructures recognised by the Ministry of Science, Innovation and Universities.

Direct links to the web portals

The data are now publicly available online following today's official launch.

The main access point is the ICTS-Doñana website: 🔗 https://icts-donana.csic.es/

Direct links to the individual portals:

🔗 https://datos-automaticos.icts-donana.es/

🔗 https://meteorologia-palacio.icts-donana.es/

Launch presentation:

🔗 https://www.youtube.com/watch?v=sFEl-bcJwjg

Un cuadro del siglo XVII documentó un comportamiento de los murciélagos que la ciencia ha confirmado recientemente

outreach@ebd.csic.es — Tue, 30 Jun 2026 11:15:08 +0000

30 June 2026

A 17th-century painting captured bat behaviour that science has only recently confirmed

A study by the Doñana Biological Station (EBD-CSIC), published in PNAS, has identified what appears to be the depiction of a noctule bat capturing a bird in a painting by Jan Brueghel the Elder, more than four centuries before this behaviour was scientifically confirmed. These findings highlight the scientific value of historical works of art as a source of information on past biodiversity and the historical understanding of the natural world.

A detail of a noctule bat hunting a bird, depicted in the painting "Air" by Jan Brueghel the Elder in 1611.

A study led by the Doñana Biological Station (EBD-CSIC) provides new evidence that the predation of passerine birds by noctule bats was already known in the 17th century, around 400 years before science was able to demonstrate it conclusively. The research analyses Air, a painting by the Flemish artist Jan Brueghel the Elder, which depicts a bat carrying a small bird in its mouth.

It is only in recent years that scientists have conclusively shown that some European bats regularly prey on migratory birds. The first robust evidence of this behaviour emerged just two decades ago through analyses of bat droppings, movement tracking and molecular techniques.

One of the most significant breakthroughs came last October, when a research team led by the Doñana Biological Station (EBD-CSIC) demonstrated that the greater noctule, the largest bat species in Europe, is capable of catching and eating birds in mid-flight. The team made the first-ever recording of a greater noctule attacking and preying on a European robin in the air at Doñana, providing the first direct evidence of this remarkable hunting behaviour.

The new study has now uncovered an intriguing historical clue in Air, painted in 1611 by Jan Brueghel the Elder and housed at the Museum of Fine Arts of Lyon. The work depicts more than 60 bird species and at least three bat species. Among them is a clearly identifiable noctule bat, most likely a giant noctule (Nyctalus lasiopterus), holding a passerine bird in its mouth.

Although the scene does not perfectly match current scientific understanding of how these bats capture their prey, the authors argue that the painting nevertheless indicates that the artist was aware of this predatory behaviour centuries before it was documented by science.

"The painting suggests that certain observations about natural history may have formed part of the visual and observational culture of the time, even if they were never formally recorded in the scientific literature," says Pedro Romero Vidal, a researcher at the Doñana Biological Station.

Art and natural history

Beyond its implications for bat ecology, the study underscores the scientific value of historical artworks as a source of information on biodiversity and animal behaviour. The digitization of museum collections, together with the detailed analysis of historical paintings, is enabling researchers to recover observations of wildlife made centuries before the emergence of modern science.

According to the research team, the study demonstrates that works of art can complement contemporary scientific research and provide unexpected insights into the natural history of the past.

Reference

Pedro Romero Vidal, Sonia Sánchez Navarro, Elena Tena, Miguel Clavero. Natural history on canvas: Brueghel knew about bird-eating noctule bats. PNAS. https://doi.org/10.1073/pnas.2536525123

Descubren cuatro nuevas especies de moscas hematófagas en Andalucía durante la vigilancia del virus del Nilo Occidental

outreach@ebd.csic.es — Mon, 29 Jun 2026 09:13:35 +0000

29 June 2026

Four new species of blood-feeding flies discovered in Andalusia during West Nile virus surveillance

Researchers from the Doñana Biological Station (EBD-CSIC) and the University of Milan have identified four new species of tiny blood-feeding flies belonging to the genus Leptoconops, an insect group of importance for public and animal health. The discovery was made during mosquito surveillance campaigns carried out to monitor the presence of West Nile virus across Andalusia.

Images of the four newly described species of the genus Leptoconops from southern Spain. Clockwise from top left: Leptoconops nigrithorax sp. nov., Leptoconops triangularis sp. nov., Leptoconops pseudoirritans sp. nov., Leptoconops communis sp. nov.

A research team led by the Doñana Biological Station (EBD-CSIC), in collaboration with the University of Milan, has identified four new species of biting midges belonging to the genus Leptoconops. These tiny blood-feeding flies—measuring just two millimetres in length—were previously unknown to science.

While the discovery of new species is often associated with remote regions or poorly explored ecosys-tems, many species remain undescribed even in countries such as Spain. Because of their importance for public and animal health, research on blood-feeding insects has expanded considerably in recent years.

The discovery was made during mosquito sampling carried out by the Doñana Biological Station to moni-tor the presence of West Nile virus at sites across Andalusia. These surveys are part of the ARBOPREVENT project, funded by the “la Caixa” Foundation through its Health Research Call.

In total, the researchers identified eight Leptoconops species, four of which—half of all the species detected—proved to be completely new to science. The newly described species are Leptoconops nig-rithorax sp. nov., Leptoconops triangularis sp. nov., Leptoconops pseudoirritans sp. nov. and Lepto-conops communis sp. nov. Their discovery significantly expands current knowledge of this medically important group of insects and demonstrates that even well-studied regions such as Andalusia still har-bour species yet to be discovered.

“This comprehensive sampling effort has, for the first time, revealed the presence of Leptoconops species in Andalusia,” says Jordi Figuerola, principal investigator of the project.

Tiny insects of public health importance

The genus Leptoconops comprises tiny blood-feeding flies. Like mosquitoes, females feed on blood by making small cuts in the skin of birds and mammals, including humans—a feeding strategy known as telmophagy.

The genus is found throughout much of the Mediterranean region, including Italy, France, Spain, Algeria, Morocco, Egypt and the Middle East. However, knowledge of its distribution remains incomplete, with some regions still largely unexplored. Although these insects are absent for most of the year, their populations can increase intensely during spring, when their bites become a significant nuisance.

“In Spain, these flies had previously been recorded from only a handful of locations and were mainly associated with sandy streambeds and salt marshes. However, our study shows that their distribution is much broader than previously thought,” explains Mikel Alexander González, lead author of the study.

Opening new research lines

This study demonstrates that even in extensively studied regions such as Andalusia, previously unknown species remain to be discovered. It also highlights the value of disease surveillance programmes, which not only contribute to the early detection of emerging pathogens but also generate valuable data that advance our understanding and conservation of biodiversity.

Co-author and PhD researcher Dumitru Ionut Paun Tanase concludes: “Capturing these insects will allow us to investigate their role in parasite transmission, as well as their ecology, helping to fill important gaps in our knowledge of this group.”

Referencia

Paun-Tanase DI, González MA, Magallanes S, Naro G, Epis S, Figuerola J (2026) Hidden diversity in Europe: new species and a revised taxonomy of the subgenus Leptoconops (Leptoconops) (Diptera, Ceratopogonidae). ZooKeys 1279: 201-239. https://doi.org/10.3897/zookeys.1279.186179

Los genes y la experiencia determinan dónde pasa el invierno una pequeña ave migratoria

outreach@ebd.csic.es — Fri, 26 Jun 2026 06:32:12 +0000

26 June 2026

Genes and experience determine where a small migratory bird spends the winter

An international study involving the Doñana Biological Station shows that the wintering areas of the European pied flycatcher are determined by both genetic inheritance and natal environment. The research reveals that all birds, from Spain to Siberia, migrate via the Iberian Peninsula and the West African coast, representing a major detour for Siberian populations. Understanding the links between breeding and wintering areas improves predictions of how migratory species may adapt to climate change.

Male European pied flycatcher in La Hiruela, Madrid. / David Ochoa

An international team of scientists, including researchers from the Doñana Biological Station (EBD) of the Spanish National Research Council (CSIC), has discovered that the African wintering grounds of the European pied flycatcher, a small migratory songbird, are determined by both genetic factors and the environmental conditions experienced during the earliest stages of life. The study, published in Science, provides one of the first experimental demonstrations of how migratory birds select their winter destinations.

Every year, millions of birds travel thousands of kilometres between their breeding and wintering grounds. In many species, individuals born in the same region tend to spend the winter relatively close to one another. However, the reasons behind this pattern have remained unknown in species such as the European pied flycatcher, which migrates alone and mostly at night, with no opportunity to learn migration routes from parents or other experienced individuals.

A 13,000-kilometre journey for a 12-gram bird

To unravel this mystery, the research team fitted geolocators to European pied flycatchers from eight breeding populations ranging from Spain to western Siberia. These miniature light sensors, weighing only a fraction of a gram, record every sunrise and sunset, allowing researchers to estimate the bird's geographical position throughout the year once the data are retrieved. After recapturing the birds at their breeding sites the following year, the team successfully reconstructed each individual's annual migration route.

The results revealed a migration pattern that was as spectacular as it was unexpected. All populations of pied flycatcher converged on the Iberian Peninsula during autumn migration before travelling south along the West African coast. After an extended stopover, the birds undertook a non-stop flight of approximately 30 hours to the westernmost tip of Africa, from where they gradually moved eastwards to occupy different wintering areas.

While Spanish birds settled in Senegal and neighbouring regions, Siberian birds continued as far as the Central African Republic after travelling nearly 13,000 kilometres. Paradoxically, a direct route across the eastern Mediterranean would have shortened their journey by around 4,500 kilometres, substantially reducing both energy expenditure and the many risks associated with migration. Yet they consistently continue to migrate via Spain.

"It is difficult to find an adaptive explanation for such an enormous detour," says Koosje Lamers, researcher at the University of Groningen and first author of the study. "Everything suggests that this route may be an evolutionary relic from a time when the species was restricted to western Europe and Africa," explains Lamers.

A combination of genes and environment

To investigate why birds from different populations winter in different regions, the researchers conducted a five-year experiment between the Netherlands and Sweden. Eggs laid by Dutch pied flycatchers were transferred to Swedish nests located 500 kilometres away, where they were incubated and raised by Swedish foster parents. The fostered chicks were later equipped with geolocators to monitor their migration. In addition, naturally occurring mixed-ancestry offspring born in Sweden from crosses between Dutch and Swedish birds were also fitted with geolocators before leaving the nest.

The differences were striking. Dutch pied flycatchers spent the winter approximately 500 kilometres farther east than Swedish birds. However, Dutch birds raised in Sweden settled in intermediate locations, while birds of mixed ancestry wintered even closer to the areas used by the Swedish population. These findings demonstrate that the winter destinations of these small migrants are determined by a combination of genetic and environmental influences. Furthermore, the results suggest that what is genetically encoded is not necessarily a specific migration route from the breeding grounds but, at least in part, the duration of the migratory programme.

The environmental effect on migration routes and final winter destinations is closely linked to migration timing. Dutch birds, breeding farther south, reproduce and migrate earlier than Swedish birds. By contrast, the shorter and later northern summer forces Swedish birds to begin migration later in the season. Genetics determines key temporal aspects such as the duration of the migration programme, while the natal environment also influences the final destination, even among individuals with the same genetic background. This explains why Dutch birds winter farther inland in Africa, whereas Swedish birds remain farther west.

Key insights into adaptation to climate change

The study also demonstrates that wintering areas are established during the birds' first autumn migration and that individuals consistently return to the same African regions year after year. This finding has important implications in the context of global environmental change.

"The location where birds spend the winter determines when they can begin their return migration and, consequently, when they arrive at their breeding grounds," explains Carlos Camacho, migration specialist at the Doñana Biological Station. "That synchronisation is becoming increasingly important in a rapidly warming world," the researcher adds.

Understanding how breeding and wintering areas are connected will improve our ability to predict how migratory species may adapt to environmental change. It will also help develop more effective conservation strategies for birds that depend on ecosystems spanning multiple continents.

Reference

Lamers, K.P., Ouwehand, J., Ubels, R., Nicolaus, M., Camacho, C., Potti, J. … & Both, C. 2026. Innate factors and ontogeny determine non-breeding areas of migrant songbirds. Science, DOI: 10.1126/science.ads0532

El proyecto INTEGRA celebra el primer taller sobre Áreas Clave para la Biodiversidad en Andalucía

outreach@ebd.csic.es — Thu, 25 Jun 2026 11:53:26 +0000

25 June 2026

INTEGRA project celebrates its first workshop on Key Biodiversity Areas in Andalusia

The Doñana Biological Station (EBD-CSIC) hosts experts from multiple specialities to identify and validate new sites of critical importance for biodiversity in Andalusia using the IUCN Global Standard.

Dune landscape in Doñana, southern Spain. Credit: José María Pérez de Ayala

The Doñana Biological Station (EBD-CSIC) hosted the first workshop on Key Biodiversity Areas (KBAs) of the INTEGRA project during 24-26 June. Over three days, 20 experts from different taxonomic specialities, public administrations and conservation organisations came together to identify and validate new potential sites of critical importance for biodiversity in Andalusia in Southern Spain, applying the IUCN Global Standard for Key Biodiversity Areas.

The workshop brought together specialists in molluscs, plants, mammals and insects, along with protected area managers, land stewardship initiative coordinators and professionals from non-governmental conservation organisations. This multidisciplinary meeting enabled the review of proposals, the exchange of specialised knowledge and the application of the international standard that underpins the update and identification of KBAs, strengthening the scientific basis guiding conservation decisions in the region.

The INTEGRA project, which receives support from the Biodiversity Foundation of the Ministry for Ecological Transition and Demographic Challenge (MITECO), through co-financing from the European Regional Development Fund (ERDF), responds to a critical moment for national conservation. Its development coincides with the update of the Spanish Red List, the establishment of the National KBA Coordination Group and the need to consolidate fundamental international commitments: the 30x30 Target of the Global Biodiversity Framework of the Convention on Biological Diversity, the EU Nature Restoration Regulation and the National Green Infrastructure, Connectivity and Ecological Restoration Strategy.

The workshop represents the first step in a collaborative process that the INTEGRA project will develop throughout the year to identify new sites of critical importance for biodiversity in Spain. Through technical sessions, group work and a field visit to Brazo del Este (Doñana), participants deepened their understanding of KBA identification methodology and its application to assess their contribution to ecological connectivity using the methodology developed by the MEDCONECTA project.

Drive to strengthen green infrastructure

This analysis will identify priority action areas and integrate biodiversity, connectivity and ecosystem services into territorial planning. In this way, INTEGRA aims to contribute to the design of an ecologically coherent green infrastructure that is resilient to climate change and capable of providing lasting benefits to society. Territorial planning is the project's cross-cutting axis. Once KBAs have been identified and ecological corridors analysed, INTEGRA will promote the integration of green infrastructure into territorial planning instruments, adapting results to regional scale and developing case studies that demonstrate their operational viability.

Additionally, the project develops a comprehensive strategy for coordination, communication and knowledge transfer, including validation workshops, development of dissemination materials, creation of a dedicated website and ongoing engagement with relevant stakeholders in public administration, research and civil society. The objective is to ensure that INTEGRA results translate into operational tools and criteria available to planning authorities throughout Spain.