On the island of O‘ahu, Hawai‘i, USA, hundreds of the native seabird Wedge-tailed Shearwater Ardenna pacifica (WTSH) experience mortality from fallout every year. However, not all lights are created equal in their influence on seabird fallout. This study evaluated trends from standardized surveys that were conducted from 2002 to 2010 along a road with high colony density looking for WTSH fallout. Yearly fallout counts showed an oscillating two-year cycle of increasing and decreasing fallout and identified November 25th as the date with the highest fallout. Fallout individuals were found near artificial lights and utility lines at extremely high percentages; at 94% and 83% within 8 m, which was much higher than random points analyzed along the same route. Fallout was also negligible farther than 5 km from the nearest colony and occurred in a small area of the transect, where 60% of all fallout occurred along a 1.7 km section, with 27% of fallout occurring within 8 m of only two light poles, highlighting the high potential for targeted management. Outcomes of rescued shearwaters from non-fatal fallout events showed that 78% were admitted for rehabilitation with no injury and released suggesting that rescue efforts during high-risk periods that are focused within 5 km of colonies, in fallout hot spots, are likely to enhance survival in addition to light alteration at these sites. Our results specify when, where, and how targeted management could be used most effectively to reduce fallout on O‘ahu and highlight tangible and easily applicable solutions to artificial light-induced mortality on Hawaiian seabirds.
More info at: Friswold et al. 2020. Wedge-tailed Shearwater Ardenna pacifica fallout patterns inform targeted management. Marine Ornithology
The Manx shearwater Puffinus puffinus is one of the best studied seabirds worldwide. Most of the information known on this seabird is focused on the northern core populations where the species is abundant. However, the species shows a high number of peripheral populations, which are extremely small and difficult to study in comparison to central populations. Using an integrative approach, we provided evidence of phenological, morphological, acoustic, plumage colour, and genetic differentiation of the Canarian Manx shearwaters (the most southern population) from the northern breeding colonies, which is compatible with a long period of isolation. Birds from the Canary Islands breed around 2‐3 months earlier, are smaller and lighter, and show darker underwing plumage than those from northern populations. In addition, Canarian call features are different from the northern populations and genetic analyses of the mitochondrial control region indicate an incipient genetic differentiation of Canarian Manx shearwaters from the other breeding populations. The Canarian population holds a small number of breeding colonies and it is declining, so accurate taxonomic recognition critically affects conservation efforts. We propose to rank the Canarian breeding population as a new subspecies Puffinus puffinus canariensis ssp. nova.
More info at: Rodríguez et al. 2020 Cryptic differentiation in the Manx Shearwater hinders the identification of a new endemic subspecies. Journal of Avian Biology
Seabirds are impacted by coastal light pollution, where they are attracted to and disoriented by artificial light at night, often leading to massive mortality events. While adults are occasionally recorded in fallout throughout the year, this phenomenon is most severe during
fledging season and juveniles comprise the majority of affected individuals. In a newly published perspectives article in Conservation Science and Practice, we explore a connection between the visual system development of burrow nesting seabirds and the observed higher vulnerability to light pollution by seabird juveniles. Undeveloped and untrained vision at fledging, together with behavioural inexperience, could explain differences observed between age groups. Multidisciplinary research is needed to clarify such effects further mitigate light induced mortality.
More info at: Atchoi E, Mitkus M, Rodríguez A (2020) Is seabird light‐induced mortality explained by the visual system development? Conservation Science and Practice e195.
In a new article, the NGO Red de Observadores de Aves y Vida Silvestre de Chile describes new colonies, with their population estimation, phenology and threats of one of the few seabirds which still being considered as "Data Deficient" by Birdlife, the Markham’s Storm-Petrel (Oceanodroma markhami). One of the main threats described for the conservation of this storm-petrel is light pollution since there are several salt-mines and ports near one of the main colonies, where the team estimated that 20,000 fledglings are falling each year. The research team have been working for reducing the light pollution of Northern Chile, together with the Environmental Ministry, the Chilean Wildlife Service, and two rescue groups of volunteers. Thus, it is promising that the situation could change in the next years.
More into at:
Barros R, Medrano F, Norambuena HV, Peredo R, Silva R, de Groote F, Schmitt F (2019) Breeding phenology, distribution and conservation status of Markham’s Storm-Petrel Oceanodroma markhami in the Atacama Desert. Ardea 107: 75–84.
42% of petrel species are threatened and 52% are suffering population declines based on IUCN criteria. These percentages are higher than those of the Clase Aves. According to a global review on the conservation research on petrels and shearwaters, 38 researchers from 34 institutions and 10 countries have recognized light pollution as the second most severe threat for this avian group (measured as number of species affected). The most severe threat identified in this review paper were invasive species at breeding grounds, being rats the most pervasive introduced species. Other identified threats were bycatch, overfishing, climate change, and plastic pollution.
More info at:
Rodríguez A, et al (2019) Future Directions in Conservation Research on Petrels and Shearwaters. Frontiers in Marine Science DOI: 10.3389/fmars.2019.00094
Bycatch in net fisheries is recognized as a major source of mortality for many marine species, including seabirds. Few mitigation solutions, however, have been identified. In a new study authors assessed the effectiveness of illuminating fishing nets with green light emitting diodes (LEDs) to reduce the incidental capture of seabirds. Experiments were conducted in the demersal, set gillnet fishery of Constante, Peru and compared 114 pairs of control and illuminated nets. Seabird bycatch was higher in control nets than in illuminated nets, representing an 85.1% decline in the guanay cormorant (Phalacrocorax bougainvillii) bycatch rate. 39 cormorants were caught in control nets, while only 6 were caught in illuminated nets. This study showing that net illumination reduces seabird bycatch and previous studies showing reductions in sea turtle bycatch without reducing target catch indicate that net illumination can be an effective multi-taxa bycatch mitigation technique. This finding has broad implications for bycatch mitigation in net fisheries given LED technology’s relatively low cost, the global ubiquity of net fisheries, and the current paucity of bycatch mitigation solutions.
More info at: Mangel JC, Wang J, Alfaro-Shigueto J, Pingo S, Jimenez A, Carvalho F, Swimmer Y, Godley BJ (2018) Illuminating gillnets to save seabirds and the potential for multi-taxa bycatch mitigation. Royal Society Open Science 5: 180254.
For many decades, the spectral composition of lighting was determined by the type of lamp, which also influenced potential effects of outdoor lights on species and ecosystems. Light‐emitting diode (LED) lamps have dramatically increased the range of spectral profiles of light that is economically viable for outdoor lighting. Because of the array of choices, it is necessary to develop methods to predict the effects of different spectral profiles without conducting field studies, especially because older lighting systems are being replaced rapidly. We describe an approach to predict responses of exemplar organisms and groups to lamps of different spectral output by calculating an index based on action spectra from behavioral or visual characteristics of organisms and lamp spectral irradiance. We calculate relative response indices for a range of lamp types and light sources and develop an index that identifies lamps that minimize predicted effects as measured by ecological, physiological, and astronomical indices. Using these assessment metrics, filtered yellow‐green and amber LEDs are predicted to have lower effects on wildlife than high pressure sodium lamps, while blue‐rich lighting (e.g., K ≥ 2200) would have greater effects. The approach can be updated with new information about behavioral or visual responses of organisms and used to test new lighting products based on spectrum (see here). Together with control of intensity, direction, and duration, the approach can be used to predict and then minimize the adverse effects of lighting and can be tailored to individual species or taxonomic groups.
More info at
Longcore T, Rodríguez A, Witherington B, Penniman JF, Herf L, Herf M (2018) Rapid assessment of lamp spectrum to quantify ecological effects of light at night. Journal of Experimental Zoology A
Wildlife watching is an emerging ecotourism activity around the world. In Australia and New Zealand, night viewing of little penguins attracts hundreds of thousands of visitors per year. As penguins start coming ashore after sunset, artificial lighting is essential to allow visitors to view them in the dark. This alteration of the nightscape warrants investigation for any potential effects of artificial lighting on penguin behavior. We experimentally tested how penguins respond to different light wavelengths (colors) and intensities to examine effects on the colony attendance behavior at two sites on Phillip Island, Australia. At one site, nocturnal artificial illumination has been used for penguin viewing for decades, whereas at the other site, the only light is from the natural night sky. Light intensity did not affect colony attendance behaviors of penguins at the artificially lit site, probably due to penguin habituation to lights. At the not previously lit site, penguins preferred lit paths over dark paths to reach their nests. Thus, artificial light might enhance penguin vision at night and consequently it might reduce predation risk and energetic costs of locomotion through obstacle and path detection. Although penguins are faithful to their path, they can be drawn to artificial lights at small spatial scale, so light pollution could attract penguins to undesirable lit areas. When artificial lighting is required, we recommend keeping lighting as dim and time‐restricted as possible to mitigate any negative effects on the behavior of penguins and their natural habitat.
More infot at:
Rodríguez A, Holmberg R, Dann P, Chiaradia A (2018) Penguin colony attendance under artificial lights for ecotourism. Journal of Experimental Zoology A, doi: 10.1002/jez.2155
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