Artificial light at night alters the sexual behaviour and fertilisation success of the common toad. (April 2020)

• Record Type: Journal Article
• Authors: Touzot, Morgane; Lengagne, Thierry; Secondi, Jean; Desouhant, Emmanuel; Théry, Marc; Dumet, Adeline; Duchamp, Claude; Mondy, Nathalie
• Is Part Of: Environmental pollution. Volume 259(2020)
• Publication Date: 2020-04
• Subjects: Fitness -- Reproduction -- Amphibian -- Anthropogenic light pollution -- Behaviour; Pollution -- Periodicals; Pollution -- Environmental aspects -- Periodicals; Environmental Pollution -- Periodicals; Pollution -- Périodiques; Pollution -- Aspect de l'environnement -- Périodiques; Pollution -- Effets physiologiques -- Périodiques; Pollution; Pollution -- Environmental aspects; Periodicals; Electronic journals; 363.73
• DOI: 10.1016/j.envpol.2019.113883
• Languages: English
• ISSNs: 0269-7491

Abstract

Abstract: Artificial Light At Night (ALAN) is an emerging pollution, that dramatically keeps on increasing worldwide due to urbanisation and transport infrastructure development. In 2016, it nearly affected 23% of the Earth's surface. To date, all terrestrial and aquatic ecosystems have been affected. The disruption of natural light cycles due to ALAN is particularly expected for nocturnal species, which require dark periods to forage, move, and reproduce. Apart from chiropterans, amphibians contain the largest proportion of nocturnal species among vertebrates exhibiting an unfavourable conservation status in most parts of the world and living in ALAN polluted areas. Despite the growing number of studies on this subject, our knowledge on the direct influence of nocturnal lighting on amphibians is still scarce. To better understand the consequences of ALAN on the breeding component of amphibian fitness, we experimentally exposed male breeding common toads ( Bufo bufo ) to ecologically relevant light intensities of 0.01 (control), 0.1 or 5 lux for 12 days. At mating, exposed males took longer than controls to form an amplexus, i.e. to pair with a female, and broke amplexus before egg laying, while controls never did. These behavioural changes were associated with fitness alteration. The fertilisation rate of 5 lux-exposed males was reduced by 25%. Salivary testosterone, which is usually correlated with reproductive behaviours, was not altered by ALAN. Our study demonstrates that ALAN can affect the breeding behaviour of anuran species and reduce one component of their fitness. Given the growing importance of ALAN, more work is needed to understand its long-term consequences on the behaviour and physiology of individuals. It appears essential to identify deleterious effects for animal populations and propose appropriate management solutions in an increasingly brighter world. Graphical abstract: Image 1 Highlights: We tested the effects of nocturnal light on toad sexual behaviour and fertilisation. We examined the effects of different light intensities on breeding males only. Artificial light at night increased male latency to pair successfully with a female. Male testosterone concentration was not affected by artificial light at night. Artificial light at night reduced the fertilisation success of males. Abstract : Artificial light at night decreased the capacity of male Bufo bufo to form a pair with a female and reduced their fertilisation success.