Studies testing the effect of artificial light characteristics on attractiveness to seabirds have not provided conclusive results and there is some urgency as some endangered petrel species experience high light-induced mortality. We designed a field experiment to test the effect of three common outdoor lighting systems with different light spectra (high pressure sodium, metal halide and white light emitting diode) on the number and the body condition of grounded fledglings of the short-tailed shearwater Ardenna tenuirostris. A total of 235 birds was grounded during 99 experimental hours. 47% of birds was grounded when metal halide lights were on, while light emitting diode and high pressure sodium lights showed lower percentages of attraction (29% and 24%). No differences in body condition were detected among the birds grounded by the different lighting systems. We recommend the adoption of high pressure sodium lights (or with similar spectra) into petrel-friendly lighting designs together with other light mitigation measures such as light attenuation, lateral shielding to reduce spill and appropriate orientation.
Rodríguez A, Dann P, Chiaradia A (2017) Reducing light-induced mortality of seabirds: high pressure sodium lights decrease the fatal attraction of shearwaters. Journal for Nature Conservation 39: 68-72.
Rodríguez A, Moffett J, Revoltos A, Wasiak P, McIntosh RR, Sutherland DR, Renwick L, Dann P, Chiaradia A (2017) Light pollution and seabird fledglings: targeting efforts in rescue programs. Journal of Wildlife Management doi: 10.1002/jwmg.21237
Artificial lights at night cause high mortality of seabirds, one of the most endangered groups of birds globally. Fledglings of burrow-nesting seabirds, and to a lesser extent adults, are grounded by lights when they fly at night. We review the current state of knowledge of light attraction, identify information gaps and propose measures to address the problem. Although other avian families such as Alcidae and Anatidae can be involved, the most affected seabirds are petrels and shearwaters: at least 56 species, more than one-third of them (24) threatened, are grounded by lights. Grounded seabirds have been found worldwide, mainly on oceanic islands but also at some continental locations. Petrel breeding grounds confined to formerly uninhabited islands are particularly at risk from ever-growing levels of light pollution due to tourism and urban sprawl. Where it is impractical to ban external lights, rescue programs of grounded birds offer the most immediate and extended mitigation measures to reduce light-induced mortality, saving thousands of birds every year. These programs also provide useful information for seabird management. However, the data typically are fragmentary and often strongly biased so the phenomenon is poorly understood, leading to inaccurate impact estimates. We identified as the most urgent priority actions: 1) estimation of mortality and impact on populations; 2) assessment of threshold light levels and safe distances from light sources; 3) documenting the fate of rescued birds; 4) improvement of rescue campaigns, particularly in terms of increasing recovery rates and level of care; and 5) research on seabird-friendly lights to reduce attraction. More research is necessary to improve our understanding of this human-wildlife conflict and to design effective management and mitigation measures.
Rodríguez A, Holmes ND, Ryan PG, et al. 2017. A global review of seabird mortality caused by land-based artificial lights. Conservation Biology. DOI: 10.1111/cobi.12900
izeThe last 3rd February 2017, Airam Rodríguez presented the oral communication entitled "Is light pollution a barrier in the breeding habitat of seabirds" in the symposium "Current biodiversity conservation challenges" chaired by M.B. García & J. Lahoz‐Monfort within the XIV MEDECOS & XIII AEET meeting. This contribution is co-authorized by A. Rodríguez, B. Rodríguez, and J.J. Negro from Estación Biológica de Doñana (EBD-CSIC) and Grupo de Ornitología e Historia Natural de las Islas Canarias (GOHNIC) and the abstract reads:
"Many burrow-nesting seabirds are nocturnal at their breeding colonies, i.e. visit the colonies at night. Petrel and shearwater fledglings are attracted and disorientated by artificial lights at night when they leave the nest and fly for first time towards the sea. If they are ground and not rescued, they have a high probability of perishing. In contrast, adults nesting on inland colonies have to cross over the cities or avoid the lit areas to reach their nests several times during the breeding period. How birds manage that situation may offer useful information to minimise light-induced mortality. Our aim is to study the behaviour of Cory’s shearwaters Calonectris diomedea borelais during the commuting flights (adults) or dispersal (fledglings) to their breeding colonies in relation to spatial distribution of light pollution. We use GPS data-loggers to track birds from several colonies on Tenerife, Canary Islands. Nocturnal satellite imagery is employed to evaluate the spatial distribution of light polluted areas. While fledglings are attracted and grounded in the closest lights to their natal colonies, adults fly over the cities without apparently avoiding artificial lights by using the shortest distance from coastlines to their colonies. Due to high elevation of nesting colonies, return flights were longer than outgoing flights as adults glided from colony to the ocean. Artificial lights do not seem to be a problem for adult shearwaters attending their nesting colonies, but constitute an important barrier for fledglings’ dispersal."
We used 13 years of attendance data to study the effects of sun, moon, and artificial light on the attendance pattern of a nocturnal seabird, the little penguin Eudyptula minor at Phillip Island, Australia. The little penguin is the smallest and the only penguin species whose activity on land is strictly nocturnal. Automated monitoring systems recorded individually marked penguins every time they arrived at or departed from two colonies under different lighting conditions: natural night skylight and artificial lights (around 3 lux) used to enhance penguin viewing for ecotourism around sunset. Sunlight had a strong effect on attendance as penguins arrived on average after sunset and departed before sunrise. The effect of moonlight was also strong, varying according to moon phase. Fewer penguins came ashore during full moon nights. Cyclic patterns of moon effect were slightly out of phase but significantly between two colonies, which could be due to site-specific differences or presence/absence of artificial lights. Moonlight could be overridden by artificial light at our artificially lit colony, but the similar amplitude of attendance patterns between colonies suggests that artificial light did not mask the moonlight effect.
Rodríguez et al. (2016) Waddling on the Dark Side: Ambient Light Affects Attendance Behavior of Little Penguins. Journal of Biological Rhythms DOI: 10.1177/0748730415626010
Artificial lights are widely used to enhance the watching of the emergence of little penguins from the shore by tourists. We installed two parallel tunnels on a penguin pathway of a dark sky colony where no artificail lights are visible. Each tunnel displayed a light type during the two hours after sunset. Data-loggers located at the botton of the tunnels counted the number of penguins crossing through each tunnel. Camera traps were also used to record any potential anomaly in penguin behaviour. The cameras let us know that not only tourists watch the penguins when they are coming ashore: a lot of animals go there to take a look!
In that section, the most relevant news about the project and other news related to seabird conservation will be highlighted