Museo Nacional de Ciencias Naturales

Assessing temporal and spatial changes is essential to understand the real impact of wildlife hunting for human consumption and trade across tropical regions. We found 56 species of wild-trapped vertebrates offered for sale in Equatorial Guinea in 2025, by surveying urban markets and rural areas, and recorded their use, prices, and conservation status. Most of the animals (94.2%) were offered for meat consumption, while animals offered for medicine/rituals or for the pet trade reached 4.4% and 1.4% of the individuals recorded, respectively. The taxonomic composition of wild meat differed between the two main urban markets, in Malabo and Bata cities, and between these markets and their surrounding rural areas. Worryingly, the supply of globally endangered pangolins was four times greater in the source rural areas than in the Bata market. Prices were higher in urban markets than in rural areas, and higher for globally threatened species regardless of their market availability. We also compared taxonomic composition of wild meat with that collected 35 years earlier from the same two urban markets. The range of hunted species was similar, but their conservation status has worsened according to the IUCN Red List. While only two of the species recorded in 2025 were globally threatened in 1990, wildlife hunting is now involving at least 15 globally threatened and 8 near threatened species, representing 27% and 14% respectively of all the species recorded and 17% and 4% respectively of all individuals trapped. While hunting these threatened species is prohibited by law, they are sold at higher prices and with impunity due to the lack of effective law enforcement. Targeted educational campaigns to reduce demand, by changing consumer attitudes towards wild meat, together with cultural-, and development-based strategies tailored to specific taxa and user groups are urgently needed to halt the unsustainable hunting of threatened species in Equatorial Guinea. • Long-term monitoring is essential to assess the real impact of wildlife hunting across tropical regions • We surveyed wildlife offered for sale in Equatorial Guinea in 2025, and compared it with data collected 35 years ago. • We found significant changes in the proportion of species offered for meat consumption. • Hunting is now involving at least 15 globally threatened and 8 near threatened species.

Snow avalanches are significant natural hazards in mountainous regions, and their frequency and magnitude are increasingly influenced by changing climatic conditions. This study presents a multi-proxy reconstruction of snow avalanche activity over the past century (1910–2014 CE) in the Canfranc Valley, Central Spanish Pyrenees. The reconstruction integrates geomorphic mapping, dendrochronology, historical archives, and climatic data. A total of 345 trees were sampled and analysed, yielding 1322 growth disturbances (GD), which enabled the reconstruction of 30 and 27 avalanche events in the Estiviellas (ES) and Rinconada (RI) paths, respectively. The analysis was complemented by geomorphological assessments based on high-resolution LiDAR-derived terrain models, along with historical records and fieldwork validation. Also, avalanche size was estimated using a bivariate statistical model based on runout distance and width, both inferred from the most distal affected trees. These size proxies, combined with return period analyses, indicate that the largest avalanches (e.g., 1962, 1986, 1993) occurred more frequently in the second half of the 20th century, while recent decades have been characterized by smaller but more frequent events, typically confined to upper slopes. Structural Equation Modelling (SEM) was applied to examine the relationships between reconstructed avalanche activity, snowpack, climate variables, and atmospheric circulation anomalies. Results show that negative phases of the North Atlantic Oscillation (NAO) enhance precipitation and lower temperatures, thereby increasing snowpack depth and avalanche probability. Snowpack emerged as the principal mediator between meteorological variables and avalanche activity. Although long-term trends indicate increasing temperatures and precipitation, their direct influence on avalanche size was limited. These findings underscore the non-linear and threshold-dependent nature of avalanche dynamics and highlight the critical role of snowpack and regional climate variability. The observed decline in avalanche size and the shift toward smaller, more frequent events may reflect broader cryospheric transformations under warming conditions. This study provides valuable insights for risk assessment and the development of adaptive hazard management strategies in mountain environments affected by climate change. • New data has been added to the avalanche database for the Spanish Pyrenees. • Tree-ring signals provide minimum frequency and magnitude of past avalanche events. • Avalanche activity shows non-linear, threshold-driven responses to snowpack variability. • Regional climate strongly modulates avalanche occurrence and size distributions. • Recent trend toward smaller, more frequent avalanches reflects cryosphere warming.

Social interactions are vital in animal life, providing access to key information about foraging opportunities, mates, and predators. Yet in highly competitive environments, being social can be costly, as increased interaction rates may lead to more frequent aggressive encounters, favouring the development of more competitive phenotypes. Remarkably, these environmental pressures can have transgenerational effects. For example, mothers can respond to their social environment by transferring non-genetic compounds, such as hormones, to their offspring. However, evidence for an effect of social density on maternal hormone allocation and subsequent offspring social phenotypes remains scarce. Here, we experimentally manipulated social density in the blue tit (Cyanistes caeruleus) by rearranging nest-boxes before egg-laying, thus creating areas of high and low density -and likely high and low competition levels. We measured yolk testosterone and assessed nestling behaviour through a social preference test (sociability) and breathing rate (a proxy for proactivity). As predicted, mothers in low-density areas deposited less testosterone than those in high-density areas. Nestlings raised at low density showed higher sociability, though this effect was male-specific. Breathing rate had a non-linear, positive relationship with yolk testosterone concentration but was, unexpectedly, lower in high-density areas. Together, these findings suggest that competitive environments increase maternal testosterone transfer, likely promoting more competitive and less social offspring phenotypes.

In the late‐20th century, golden and Bonelli's eagles suffered population declines on the Iberian Peninsula, partly due to human persecution. Habitat assessments – especially for Bonelli's eagles – always found or assumed strong associations with cliffs that provided nesting sites. However, in recent years these eagles have increasingly used trees for nests in this region. Using multi‐decadal surveys of golden and Bonelli's eagle fledglings at nests across Andalusia in southern Spain, we compared the number of young fledged in tree nests to the number reared in the more numerous cliff nests. We evaluated alternative hypotheses with an Information Theoretic approach to test whether increased use of trees resulted from growing populations relying on lower quality habitat or whether trees provide equivalent or higher quality nest‐sites that were previously unused. Reproductive rates of Bonelli's eagles were substantially higher in tree nests, while reproductive rates of golden eagles were similar between trees and cliffs. We found no difference in reproductive rates between trees and cliffs within territories that contained both types. Our results illustrate the difficulty in characterizing a species' habitat following a population decline or range restriction. Golden and Bonelli's eagles were intensively persecuted in Spain, which may have precluded them from nesting in trees that were easily accessed by humans. We should be cautious in making judgements about the quality or totality of habitat when we know a species no longer occupies the full extent of its former range. Overly narrow and inflexible definitions of a species' habitat in these cases may impede eventual recovery efforts for the species in question.

Incubation is vital for avian embryo development but demands significant parental investment, potentially at the cost of self‐maintenance and immune function. For example, the acute phase response (APR), a systemic reaction against inflammation, infection or tissue injury, can trigger sickness behaviours such as reduced activity and foraging. At the same time, immune activation may serve as an internal cue that prompts birds to prioritize current reproduction over potential future reproductive opportunities. In this study, we experimentally exposed wild European Pied Flycatcher Ficedula hypoleuca females to an immune challenge through lipopolysaccharide (LPS) injection to investigate the effects of immune activation on female incubation behaviour and its reproductive consequences. We found a clear reduction in the average duration of incubation and recess sessions in those birds administered with LPS, as well as a tendency to increase the number of incubation sessions, while other behaviours remained unaffected. These changes had no apparent effects on fitness‐related traits of females, but they were related to fledging success, which was higher in females administered with LPS. These findings suggest that females can maintain sufficient incubation conditions while simultaneously sustaining their own fitness during immune activation, as well as a compensation for potential future reproductive failures by the prioritization of immediate reproduction.

In tropical mountains, extreme hydrometeorological hazards have the potential to produce significant geomorphic changes that influence flood hazard dynamics. Although considerable research has been devoted to the geomorphic response of catchments to flood in temperate areas, comparatively little attention has been paid to the geomorphic and hydrological impacts of hurricanes in tropical mountainous areas. It is thus crucial to identify and quantify the differential response of catchments to these events and to integrate those changes into the corresponding flood hazard analyses. In this study, we address three key research questions: (1) What are the geomorphic impacts triggered by hurricanes in mountainous regions at the river reach scale? (2) To what extent do neighboring catchments differ in their response to hurricanes? (3) How do hurricane-induced geomorphic changes influence flood hazard dynamics? For that, we investigate the geomorphic response and flood hazard of two catchments in the Sierra de las Minas (Guatemala), Pasabien and Jones, by analyzing their response to cascading events triggered by Hurricane Mitch in 1998 and Hurricanes Eta and Iota in 2020. We use an integrated approach that combines UAV and satellite-based remote sensing analyses, field-based evidence and physically based modeling to analyze landform and flood extent changes after the events. The overall results indicate that hurricanes have the capacity to impact flood hazard dynamics as they play a key role in landscape evolution, and that the storm characteristics, together with physiographic characteristics of the catchment, condition their differential geomorphic impact . These results have strong implications for disaster risk reduction, especially in the light of the ongoing urbanization process and the increasing frequency of hydrometeorological extreme in tropical mountains. • Hurricanes Eta-Iota triggered divergent geomorphic responses and flood hazards in adjacent catchments. • Catchment physiography controls landslide susceptibility and post-hurricane channel response. • Hurricanes Eta-Iota mobilized vast coarse sediment, driving river widening, avulsion, and floodplain change. • An integrated multi-method approach reconstructs cascading hazards in data-scarce tropical mountain regions.

The reference genomes of Culex laticinctus, Culex modestus, Culex perexiguus, and Culex theileri offer crucial resources for exploring the genetic basis of vector competence for different pathogens, including the emerging West Nile virus. Each genome was assembled into three contiguous chromosomal pseudomolecules. These chromosome-level assemblies encompass 834, 698, 436, and 934 Mb, respectively. They are composed of 3,284, 4,220, 1,917, and 2,704 contigs and 312, 979, 475, and 709 scaffolds, with contig N50 values of 434, 313, 473, and 770 kb, and scaffold N50 values of 292, 246, 150, and 281 Mb, respectively. These genomes offer an essential genomic resource for advancing our understanding of Culex evolution and population genomic analyses, which will help to implement sustainable mosquito control efforts and disease prevention.