Anthropogenic Sources of Non-Migratory Avian Mortalities In Singapore

Abstract

Although urban spaces are increasingly recognised as viable habitats for wildlife, cities remain a major source of anthropogenic mortality for wild birds. While the sources of urban avian mortalities have been well documented in North America, these phenomena remain poorly studied in Southeast Asia, especially for resident species. Here we present the first summary of non-migratory urban bird mortalities for the heavily urbanised island of Singapore. We conducted a citizen science study using print and social media outreach to encourage members of the public to report their observations of dead birds between November 2013 and October 2017, and collected a total of 362 mortality records across 65 resident bird species and five mortality sources. Our results show that a diverse array of bird species is directly impacted by anthropogenic sources of mortality, although mortalities stemming from roadkill and cat predation are likely to be undersampled. We also find that forest-edge frugivores such as the Pink-necked Green Pigeon are likely to be especially vulnerable to building collisions. Our study shows that despite its limitations, opportunistic sampling using citizen science can generate large amounts of ecological data at relatively low cost, and serve as a cost-effective complement to standardised survey methodologies.

Hitchhiking into the future on a fly: Toward a better understanding of phoresy and avian louse evolution (Phthiraptera) by screening bird carcasses for phoretic lice on hippoboscid flies (Diptera)

“…Loss et al (2014) estimate that between 365 and 988 million birds die from window collisions in the United States alone and Grilo et al (2020) estimate 194 million annual bird road kills in Europe. In Singapore, Tan et al (2017) collected carcasses of 104 non‐migratory and 204 migratory birds from 2013 to 2017 despite avoiding common species. We predict that hundreds of new phoresy records could be obtained via carcass screening within a short time period, especially if additional fly specimens were sourced from bird ringing initiatives.…”

“…We collected bird carcasses reported by citizen scientists in Singapore as part of a long‐term project to monitor avian mortality due to window‐collisions or road accidents (Low et al, 2017; Tan et al, 2017). Carcasses collected between 2013 and 2019 were identified to species based on the Clements et al (2019) checklist, bagged separately, and stored at −20°C.…”

“…We collected bird carcasses reported by citizen scientists in Singapore as part of a long-term project to monitor avian mortality due to window-collisions or road accidents (Low et al, 2017;Tan et al, 2017). Carcasses collected between 2013 and 2019 were identified to species based on the Clements et al ( 2019) checklist, bagged separately, and stored at À20 C. We brushed 131 bird specimens (54 species) for lice and hippoboscid flies using a toothbrush and preserved all ectoparasites in 95% ethanol at À20 C. We then identified hippoboscid flies carrying lice using a Nikon SMZ460 stereomicroscope (Maa, 1966a(Maa, , 1966b(Maa, , 1969a(Maa, , 1969c(Maa, , 1969d.…”

Riding into the future on a fly: toward a better understanding of phoresy and avian lice evolution (Phthiraptera) by screening bird carcasses for phoretic lice on hippoboscid flies (Diptera)

“…Obtaining the new phoresy records was not time consuming because finding hippoboscid flies on bird carcasses is fast and the number of birds that are killed annually is vast: Loss et al (2014) estimate that between 365 and 988 million birds die from window collisions in the United States alone and Grilo et al (2020) estimate 194 million annual bird road kills in Europe. In Singapore, Tan et al (2017) collected 104 non-migratory and 204 migratory bird carcasses between 2013 to 2017 despite avoiding common species. We predict that hundreds of new phoresy records could be obtained via carcass screening within a short time period, especially if additional fly specimens were sourced from bird ringing initiatives.…”

“…We collected bird carcasses reported by citizen scientists in Singapore as part of a longterm project to monitor avian mortality due to window-collisions or road accidents (Low et al, 2017;Tan et al, 2017). Carcasses collected between 2013 and 2019 were bagged separately and stored at -20°C.…”