Auditory performance in bald eagles and red-tailed hawks: a comparative study of hearing in diurnal raptors

McGee, JoAnn; Ponder, Julia; Marr, Jeff; Redig, Patrick T.; Walsh, Edward J.

doi:10.1007/s00359-019-01367-9

Cited by 17 publications

(15 citation statements)

References 113 publications

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“…We tested six different pure tones (0.5, 1, 2, 3, 4, 5 kHz). This is a standard tone range shown to be processed well in many bird species ( Dooling, 1982 ), including bald eagles and red-tailed hawks ( McGee et al , 2019 ). While some songbirds show reasonably good processing of tones higher than 5 kHz (e.g.…”

Section: Methodsmentioning

confidence: 99%

“…While some songbirds show reasonably good processing of tones higher than 5 kHz (e.g. Vélez et al , 2015 ), we limited our tests to a maximum of 5 kHz because evidence suggested that eagles were not particularly good at processing tones above 5 kHz ( McGee et al , 2019 ), and adding additional tones above 5 kHz would impact our ability to test the additional sounds in our study. We randomized the order of the six tones for each eagle, but all treatments for an individual eagle received the same six-tone order.…”

Section: Methodsmentioning

confidence: 99%

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Selecting auditory alerting stimuli for eagles on the basis of auditory evoked potentials

Goller

Baumhardt

Dominguez‐Villegas

et al. 2022

Conservation Physiology

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Development of wind energy facilities results in interactions between wildlife and wind turbines. Raptors, including bald and golden eagles, are among the species known to incur mortality from these interactions. Several alerting technologies have been proposed to mitigate this mortality by increasing eagle avoidance of wind energy facilities. However, there has been little attempt to match signals used as alerting stimuli with the sensory capabilities of target species like eagles. One potential approach to tuning signals is to use sensory physiology to determine what stimuli the target eagle species are sensitive to even in the presence of background noise, thereby allowing the development of a maximally stimulating signal. To this end, we measured auditory evoked potentials of bald and golden eagles to determine what types of sounds eagles can process well, especially in noisy conditions. We found that golden eagles are significantly worse than bald eagles at processing rapid frequency changes in sounds, but also that noise effects on hearing in both species are minimal in response to rapidly changing sounds. Our findings therefore suggest that sounds of intermediate complexity may be ideal both for targeting bald and golden eagle hearing and for ensuring high stimulation in noisy field conditions. These results suggest that the sensory physiology of target species is likely an important consideration when selecting auditory alerting sounds and may provide important insight into what sounds have a reasonable probability of success in field applications under variable conditions and background noise.

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Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Selecting auditory alerting stimuli for eagles on the basis of auditory evoked potentials

Goller

Baumhardt

Dominguez‐Villegas

et al. 2022

Conservation Physiology

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“…This pattern could also be affected by taxonomic differences in auditory sensitivities. In general, larger avian taxa have poorer hearing at higher frequencies [47,49,50].…”

Section: Plos Onementioning

confidence: 99%

“…hear sounds up to 8 kHz at 70 dBA SPL (see playback conditions below) [47,49]. Many nonsongbird species have peak sensitivities closer to 2 kHz and likely have more difficulty hearing sounds as high-pitched as 8 kHz at 70 dBA SPL [47,50]. We generated these acoustic stimuli using PRAAT (version 6.0.46; [51]) and edited files in Audacity(R) (version 2.4.1; https:// audacityteam.org/).…”

Section: Plos Onementioning

confidence: 99%

“…A delayed and less robust response to the 6-8 kHz sound compared with the 4-6 kHz sound supports our prediction that the 4-6 kHz sound is more audible and will be more effective in altering the birds' attention and perception of risk during flight. Reviews of avian auditory sensitivity indicate that most bird species have more sensitive hearing in the 4-6 kHz compared with the 6-8 kHz range [47,49,50]. We tested the effects of the 6-8 kHz sound as there should be less interference and possibly less auditory masking with this sound because it is clearly further frequency-shifted from the lower frequency background noise of the environments in which we performed our tests [48].…”

Section: Plos Onementioning

confidence: 99%

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Field testing an “acoustic lighthouse”: Combined acoustic and visual cues provide a multimodal solution that reduces avian collision risk with tall human-made structures

et al. 2021

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Billions of birds fatally collide with human-made structures each year. These mortalities have consequences for population viability and conservation of endangered species. This source of human-wildlife conflict also places constraints on various industries. Furthermore, with continued increases in urbanization, the incidence of collisions continues to increase. Efforts to reduce collisions have largely focused on making structures more visible to birds through visual stimuli but have shown limited success. We investigated the efficacy of a multimodal combination of acoustic signals with visual cues to reduce avian collisions with tall structures in open airspace. Previous work has demonstrated that a combination of acoustic and visual cues can decrease collision risk of birds in captive flight trials. Extending to field tests, we predicted that novel acoustic signals would combine with the visual cues of tall communication towers to reduce collision risk for birds. We broadcast two audible frequency ranges (4 to 6 and 6 to 8 kHz) in front of tall communication towers at locations in the Atlantic migratory flyway of Virginia during annual migration and observed birds’ flight trajectories around the towers. We recorded an overall 12–16% lower rate of general bird activity surrounding towers during sound treatment conditions, compared with control (no broadcast sound) conditions. Furthermore, in 145 tracked “at-risk” flights, birds reduced flight velocity and deflected flight trajectories to a greater extent when exposed to the acoustic stimuli near the towers. In particular, the 4 to 6 kHz stimulus produced the greater effect sizes, with birds altering flight direction earlier in their trajectories and at larger distances from the towers, perhaps indicating that frequency range is more clearly audible to flying birds. This “acoustic lighthouse” concept reduces the risk of collision for birds in the field and could be applied to reduce collision risk associated with many human-made structures, such as wind turbines and tall buildings.

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Accipitriformes Sensory Systems

Kelber¹

2021

Encyclopedia of Animal Cognition and Behavior

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Auditory performance in bald eagles and red-tailed hawks: a comparative study of hearing in diurnal raptors

Cited by 17 publications

References 113 publications

Selecting auditory alerting stimuli for eagles on the basis of auditory evoked potentials

Selecting auditory alerting stimuli for eagles on the basis of auditory evoked potentials

Field testing an “acoustic lighthouse”: Combined acoustic and visual cues provide a multimodal solution that reduces avian collision risk with tall human-made structures

Accipitriformes Sensory Systems

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