Scavenger removal: Bird and bat carcass persistence in a tropical wind farm

Villegas-Patraca, Rafael; Macías-Sánchez, Samuel; MacGregor-Fors, Ian; Muñoz-­Robles, Carlos

doi:10.1016/j.actao.2012.06.004

Cited by 33 publications

(23 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For example, Erickson et al (2000) reported an average survival time of 25.0 days in Oregon, whereas Smallwood et al (2010) reported 4.45 days in California. Villegas-Patraca et al (2012) reported similar results in Mexico to those of Smallwood et al (2010). Each of these studies had larger average survival times than our study, which suggests that the results from wind turbine studies are not accurate for use in estimates of urban bird-window collision fatalities.…”

Section: Scavenger Removal Across Studiessupporting

confidence: 56%

“…To date, estimates of carcass removal rates by scavengers and the bias created in estimates of avian mortality rates from human activities have been estimated primarily at wind farms, at power lines, and in pastures (Balcomb 1986, Tobin and Dolbeer 1990, Wobeser and Wobeser 1992, Ragg et al 2000, Kostecke et al 2001, Smallwood 2007, Prosser et al 2008, Ponce et al 2010, Smallwood et al 2010, Villegas-Patraca et al 2012, Bispo et al 2013, Smallwood 2013. Two studies have estimated carcass removal by scavengers in an urban landscape (Table 1).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Use of bird carcass removals by urban scavengers to adjust bird-window collision estimates

Kummer¹,

Nordell²,

Berry³

et al. 2016

ACE

View full text Add to dashboard Cite

ABSTRACT. Carcass removal by scavengers has been identified as one of the largest biases in estimating bird mortality from anthropogenic sources. Only two studies have examined carcass removal by scavengers in an urban environment, and previous estimates of bird-window collision mortality at houses have relied on carcass removal rates from wind turbine studies. We placed a bird carcass and time-lapse camera at 44 houses in Edmonton, Alberta. In total, 166 7-day trials were conducted throughout 2015. Time-to-event (survival) analysis was used to identify covariates that affected removal. The carcass removal rate was determined for use in estimating the number of birds killed from bird-window collisions at houses in Alberta. In total, 67.5% of carcasses were removed. The date the carcass was placed, the year the house was built, and the level of development within 50 m of the house were the covariates that had the largest effect on carcass removal. In calculating our removal rate, the number of detected carcasses in the first 24 hours was adjusted by 1.47 to account for removal by scavengers. Previously collected citizen science data were used to create an estimate of 957,440 bird deaths each year in Alberta as a result of bird-window collisions with houses. This number is based on the most detailed bird-window collision study at houses to date and a carcass removal study conducted in the same area. Similar localized studies across Canada will need to be completed to reduce the biases that exist with the previous bird-window collision mortality estimate for houses in Canada. Incorporation du prélèvement de carcasses d'oiseaux par les charognards urbains dans l'estimation du taux de collision des oiseaux avec les fenêtresRÉSUMÉ. Le prélèvement de carcasses par les charognards a été identifié comme un des biais les plus importants dans l'estimation de la mortalité d'oiseaux attribuable à des causes d'origine humaine. Seules deux études ont examiné le prélèvement de carcasses par les charognards en milieu urbain, et les estimations précédentes de la mortalité d'oiseaux par collision avec les fenêtres de maisons ont utilisé des taux de prélèvement de carcasses provenant d'études réalisées pour les éoliennes. Nous avons déposé des carcasses d'oiseaux et positionné des caméras à prises de vues par intervalle à 44 maisons à Edmonton, Alberta. En tout, 166 essais de 7 jours ont été effectués en 2015. Une analyse du temps d'apparition de l'événement (survie) a été faite pour déterminer les covariables qui agissent dans le prélèvement de carcasses. Le taux de prélèvement de carcasses a été établi afin d'être subséquemment utilisé dans l'estimation du nombre d'oiseaux morts par collision avec les fenêtres de maisons en Alberta. Nous avons estimé ce taux à 67,5 %. La date de dépôt de la carcasse, l'année de construction de la maison et le degré d'urbanisation dans un rayon de 50 m de la maison étaient les covariables qui avaient le plus d'effets sur le prélèvement de carcasses. Dans notre calcul du taux de prélèvement, le nom...

show abstract

Section: Scavenger Removal Across Studiessupporting

confidence: 56%

Section: Introductionmentioning

confidence: 99%

Use of bird carcass removals by urban scavengers to adjust bird-window collision estimates

Kummer¹,

Nordell²,

Berry³

et al. 2016

ACE

View full text Add to dashboard Cite

show abstract

“…() noted a similar pattern (two diurnal and six nocturnal scavenging events) based on a smaller sample size of trials in Illinois, and Villegas‐Patraca et al. () reported that >80% of carcasses were removed between 17:00 and 07:00 in Mexico. This concentration of scavenging activity at night is perhaps unsurprising given that three of the four species we most frequently observed scavenging bird carcasses (cat, opossum, skunk) are largely nocturnal.…”

Section: Discussionmentioning

confidence: 76%

“…, Villegas‐Patraca et al. ). Regardless of the explanation, this finding further illustrates that a full understanding of how scavengers detect and remove carcasses requires parsing apart the factors influencing the time to scavenging, whether or not any carcass remains persist after scavenging, and the time to complete carcass removal.…”

Section: Discussionmentioning

confidence: 98%

Factors influencing experimental estimation of scavenger removal and observer detection in bird–window collision surveys

Riding

Loss

2018

Ecological Applications

View full text Add to dashboard Cite

Wildlife collisions with human-built structures are a major source of direct anthropogenic mortality. Understanding and mitigating the impact of anthropogenic collisions on wildlife populations require unbiased mortality estimates. However, counts of collision fatalities are underestimated due to several bias sources, including scavenger removal of carcasses between fatality surveys and imperfect detection of carcasses present during surveys. These biases remain particularly understudied for bird-window collisions, the largest source of avian collision mortality. In Stillwater, Oklahoma, USA, we used bird carcasses collected during window collision monitoring to experimentally assess factors influencing scavenging and observer detection, and we employed trail cameras to characterize the scavenger community and timing of scavenging. We recorded nine scavenger species, but the domestic cat and Virginia opossum were responsible for 73% of known-species scavenging events. The most frequent scavenger species were primarily nocturnal, and 68% of scavenging events occurred at night. Scavenger species best predicted time to first scavenging event, season best predicted carcass persistence time, and both season and carcass size predicted whether any carcass remains persisted after scavenging. Our results also suggest that observer detection was influenced by substrate, with greater detection of carcasses on artificial substrates. Our findings related to scavenging timing have important implications for the unbiased estimation of collision mortality because the timing of peak scavenging relative to timing of peak mortality can substantially influence accuracy of adjusted mortality estimates. Further, the differences in correlates for time to first scavenging and time to carcass removal (i.e., persistence time) illustrate the importance of explicitly measuring these often-independent events that are frequently conflated in the anthropogenic mortality literature.

show abstract

“…In the Oaxacan Isthmus region of Mexico, 32 of the 42 species of bats known to occupy this region (García-Grajales and Silva 2012;Briones-Salas et al 2013) were found killed (Villegas-Patraca et al 2012). These bats belonged to five different families (Mormoopidae, Molossidae, Vespertilionidae, Phyllostomidae, and Emballonuridae), although 52 % of the fatalities belonged to just two species, Davy's naked-backed bat (Pteronotus davyi; 40.2 %) and the ghost-faced bat (Mormoops megalophylla; 11.9 %), both of the family Mormoopidae.…”

Section: North Americamentioning

confidence: 99%

Impacts of Wind Energy Development on Bats: A Global Perspective

Arnett

Baerwald

Mathews

et al. 2015

Bats in the Anthropocene: Conservation of Bats in a Changing World

Self Cite

125

View full text Add to dashboard Cite

Wind energy continues to be one of the fastest growing renewable energy sources under development, and while representing a clean energy source, it is not environmentally neutral. Large numbers of bats are being killed at utilityscale wind energy facilities worldwide, raising concern about cumulative impacts of wind energy development on bat populations. We discuss our current state of knowledge on patterns of bat fatalities at wind facilities, estimates of fatalities, mitigation efforts, and policy and conservation implications. Given the magnitude and extent of fatalities of bats worldwide, the conservation implications of understanding and mitigating bat fatalities at wind energy facilities are critically important and should be proactive and based on science rather than being reactive and arbitrary.

show abstract

Scavenger removal: Bird and bat carcass persistence in a tropical wind farm

Cited by 33 publications

References 19 publications

Use of bird carcass removals by urban scavengers to adjust bird-window collision estimates

Use of bird carcass removals by urban scavengers to adjust bird-window collision estimates

Factors influencing experimental estimation of scavenger removal and observer detection in bird–window collision surveys

Impacts of Wind Energy Development on Bats: A Global Perspective

Contact Info

Product

Resources

About