Biology subjects

Diaz-Palma, S.

Publications and source records attributed to Diaz-Palma, S..

3 recordsLinked to original sources

bioRxiv2025

Artificial light at night consistently impacts avian physiology and behaviour: a meta-analysis

Artificial light at night (ALAN) is a major anthropogenic pressure across the tree of life, driving population declines in insects and reptiles. Avian responses to ALAN defy simple patterns, varying in direction and magnitude, and the consequences of these responses remain unresolved. We conducted a meta-analysis to test how ALAN alters physiological, behavioural and life history traits underpinning avian performance. We analysed 623 effect sizes from 36 studies in 30 species. We found consistent physiological and behavioural shifts under ALAN, while life-history traits were unaffected. ALAN disrupted molecular and endocrine processes, leading to reduced sleep, higher metabolic rate, and accelerated reproductive maturation. Behaviourally, daily activity was extended, with earlier onset, later offset, and increased nocturnal activity and foraging effort. ALAN effects were stronger in migratory species and more pronounced in adults and females than nestlings and males. Higher light intensities amplified activity shifts, ageing, and sleep disruption, whereas exposure below 2 lux had minimal impact. Birds appear to buffer ALAN effects through physiological and behavioural adjustments, minimising impacts on life-history traits, a paradox likely explained by phenotypic plasticity or evolutionary adaptation. We identified light intensity threshold and group-specific vulnerabilities, emphasizing the need for targeted conservation in our increasingly illuminated world.

ecology↗

bioRxiv2025

Awake and hungry: artificial light at night disrupts behaviour and reproductive ecology in a wild migratory bird

Artificial light at night (ALAN), a growing consequence of global urbanisation, disrupts natural light cues that regulate biological rhythms across taxa. However, the behavioural pathways linking ALAN exposure to broader ecological impacts remain poorly understood. Here, we experimentally introduced ALAN into nestboxes of a long-distance migratory bird, the collared flycatcher (Ficedula albicollis), breeding in Gotland, Sweden, to assess ALAN effects on development and reproductive ecology. Nestlings were exposed to ALAN from two days post-hatching until fledging, and we video-recorded parental and nestling activity over 24 hours on day 8 post-hatching. From a high-resolution behavioural dataset (32,100 nestling and 3,709 parental events), we found that ALAN-exposed nestlings begged more frequently and for longer at night compared to dark controls, revealing disrupted nocturnal behaviour. These effects cascaded to parental care: both females and males in ALAN nests extended their daily activity, initiating feeding earlier and terminating later, but traded off this extension by reducing their hourly feeding counts compared to parents in dark conditions. Consequently, nestlings under ALAN fledged at an older age and had a lower fledging rate after day eight post-hatching, despite no difference in total fledging numbers compared to controls. Our findings provide the first comprehensive experimental evidence that ALAN alters the behaviour of both parents alongside their offspring and reduces reproductive success in a long-distance migrant, a species group that increasingly encounters light pollution during nocturnal migration. ALAN, though directly affecting mainly nestlings and females in nestboxes, triggered socially-mediated responses that altered the circadian behaviour of entire bird families. This study underscores the need to consider behavioural disruption as a critical mechanism underlying the ecological impacts of ALAN in natural populations. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=118 SRC="FIGDIR/small/658843v1_ufig1.gif" ALT="Figure 1"> View larger version (45K): org.highwire.dtl.DTLVardef@1808fborg.highwire.dtl.DTLVardef@1f5bfd1org.highwire.dtl.DTLVardef@104607borg.highwire.dtl.DTLVardef@5a3604_HPS_FORMAT_FIGEXP M_FIG Summary figure: Cascading effects of artificial light at night, an aspect of human-induced light pollution, on the behaviour and reproductive ecology of collared flycatchers C_FIG

ecology↗

bioRxiv2018

A simple Dot Blot Assay for population scale screening of DNA methylation

The study of epigenetic changes in natural and experimental populations has increased the need to find a cost-effective and high throughput method to analyze multiple samples to effectuate a population-wide screening to study epigenetic changes triggered by biotic or abiotic stress. One of the most studied epigenetic marks is global DNA methylation, its measurement is used as a first step to differentiate methylation between individuals. There is a wide range of methods designed to detect genome-wide 5 methyl-cytosine (5mC) that differ in sensitivity, price, level of expertise required, but as a general rule, require large amounts of DNA and are relatively expensive. This is a limit for the analysis of 5mC in a large number of individuals as a prerequisite to population-wide testing of methylation markers. In this work, we evaluated a method based on antibody recognition of 5mC to measure the DNA methylation level of individuals of the species Biomphalaria glabrata, the intermediate host of schistosomiases, a neglected tropical disease. We validated the method to complete a large screening in the genome of B. glabrata snails treated with a chemical inhibitor of DNA methylation; however, the method can be applied to any species containing 5mC. The dot blot assay is a suitable method to perform a large-scale screening of global DNA methylation to compare 5mC levels between individuals from different natural or experimental populations. The dot blot method compares favorably with methods with an equivalent sensitivity such as the Enzyme Linked Immunosorbent Assay (ELISA) kit since it requires a smaller amount of DNA (30 ng) is less expensive and allows many more samples to be analyzed.

ecology↗