Optimal Localization by Pointing Off Axis

Yovel, Yossi; Falk, Ben; Moss, Cynthia F.; Ulanovsky, Nachum

doi:10.1126/science.1183310

Cited by 123 publications

(131 citation statements)

References 26 publications

Supporting

Mentioning

124

Contrasting

Order By: Relevance

“…The rats had the fallback of casting behaviour on losing the trail, an assumption of the trail continuing in a straight direction, a sampling rate that matched their movement pattern to provide efficiency and a stereo nostril comparison to further improve accuracy. Also, they did not track only the edge of a wide trail as had been predicted 25 a repertoire of behaviours connected with rules (in short, a strategy) that the rats bring to this task. This supports the claim that we are studying a naturally relevant behaviour.…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Rats track odour trails accurately using a multi-layered strategy with near-optimal sampling

2012

View full text Add to dashboard Cite

Tracking odour trails is a crucial behaviour for many animals, often leading to food, mates or away from danger. It is an excellent example of active sampling, where the animal itself controls how to sense the environment. Here we show that rats can track odour trails accurately with near-optimal sampling. We trained rats to follow odour trails drawn on paper spooled through a treadmill. By recording local field potentials (LFPs) from the olfactory bulb, and sniffing rates, we find that sniffing but not LFPs differ between tracking and non-tracking conditions. Rats can track odours within ~1 cm, and this accuracy is degraded when one nostril is closed. moreover, they show path prediction on encountering a fork, wide 'casting' sweeps on encountering a gap and detection of reappearance of the trail in 1-2 sniffs. We suggest that rats use a multi-layered strategy, and achieve efficient sampling and high accuracy in this complex task.

show abstract

Section: Discussionmentioning

confidence: 99%

“…Using this logic, a recent study has predicted that the zigzagging of a rat's nose should be centred on the edge of the trail and not on its centre, similar to bats directing their ultrasonic clicks on the edges of objects instead of directly at them 25 .…”

Section: Rats Do Not Favour 'Off Centre' Edge Trackingmentioning

confidence: 99%

Rats track odour trails accurately using a multi-layered strategy with near-optimal sampling

2012

View full text Add to dashboard Cite

show abstract

“…Previous studies have intensively examined spatial attention to a particular target (7)(8)(9)(10)(11)(12)(13)(14). However, in fact, predators usually capture successive prey items (e.g., aerial-feeding bats) (21).…”

Section: Discussionmentioning

confidence: 99%

“…Therefore, their attention in terms of the sonar (sonar attention) is characterized as the direction to which bats emit their sonar beams (12)(13)(14). When echolocating bats approach an airborne insect, the sonar attention directs toward the prey (12,13).…”

mentioning

confidence: 99%

Echolocating bats use future-target information for optimal foraging

Fujioka

Aihara

Sumiya

et al. 2016

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

When seeing or listening to an object, we aim our attention toward it. While capturing prey, many animal species focus their visual or acoustic attention toward the prey. However, for multiple prey items, the direction and timing of attention for effective foraging remain unknown. In this study, we adopted both experimental and mathematical methodology with microphone-array measurements and mathematical modeling analysis to quantify the attention of echolocating bats that were repeatedly capturing airborne insects in the field. Here we show that bats select rational flight paths to consecutively capture multiple prey items. Microphone-array measurements showed that bats direct their sonar attention not only to the immediate prey but also to the next prey. In addition, we found that a bat's attention in terms of its flight also aims toward the next prey even when approaching the immediate prey. Numerical simulations revealed a possibility that bats shift their flight attention to control suitable flight paths for consecutive capture. When a bat only aims its flight attention toward its immediate prey, it rarely succeeds in capturing the next prey. These findings indicate that bats gain increased benefit by distributing their attention among multiple targets and planning the future flight path based on additional information of the next prey. These experimental and mathematical studies allowed us to observe the process of decision making by bats during their natural flight dynamics.bat sonar | aerial capture | microphone array | mathematical modeling | flight dynamics S electively focusing attention on a particular target allows us to effectively extract information (1-4). Animals spatially focus their attention toward prey for suitable foraging (5, 6). During prey pursuit, most animals direct their visual attention toward it [e.g., tiger beetle (7), dragonfly (8), and falcon (9)]. Specifically, for example, dragonflies maintain a prey item at a constant retinal position during approaching it so that they steer an interception flight path (interception strategy) (10). However, for multiple prey items, the direction and timing of attention for effective foraging remain unknown.Echolocating bats actively emit sonar signals to obtain surrounding information and adaptively change the characteristics of the emissions depending on the situation (11). Therefore, their attention in terms of the sonar (sonar attention) is characterized as the direction to which bats emit their sonar beams (12-14). When echolocating bats approach an airborne insect, the sonar attention directs toward the prey (12, 13). During natural foraging, the sonar attention of bats alternately shifts from their flying direction to the side (15). Additionally the wild bats are capable of capturing two prey items within the short interval of 1 s (16).We predicted that bats localize multiple prey items by distributing their attention between them and then select an efficient flight path to successively capture the multiple prey. To test this prediction, ...

show abstract

“…For the purpose of this paper, we define LDC bats as those producing signals with a duration <25% of their signal period during the search phase of echolocation. Most LDC bats produce echolocation calls with their larynx, although a handful of species in the family Pteropodidae use tongue clicks (Griffin et al, 1958;Yovel et al, 2010).HDC bats avoid auditory masking by separating pulse and echo in frequency, allowing them to broadcast calls and receive echoes at the same time (Schuller, 1974;Schuller, 1977). HDC bats take advantage of information contained in Doppler-shifted echoes generated by the relative movements of bat and target, including acoustic glints generated by the wingbeats of fluttering insects.…”

mentioning

confidence: 99%

Evolution of high duty cycle echolocation in bats

Fenton

Faure

Ratcliffe

2012

Journal of Experimental Biology

112

129

View full text Add to dashboard Cite

SummaryDuty cycle describes the relative ʻon timeʼ of a periodic signal. In bats, we argue that high duty cycle (HDC) echolocation was selected for and evolved from low duty cycle (LDC) echolocation because increasing call duty cycle enhanced the ability of echolocating bats to detect, lock onto and track fluttering insects. Most echolocators (most bats and all birds and odontocete cetaceans) use LDC echolocation, separating pulse and echo in time to avoid forward masking. They emit short duration, broadband, downward frequency modulated (FM) signals separated by relatively long periods of silence. In contrast, bats using HDC echolocation emit long duration, narrowband calls dominated by a single constant frequency (CF) separated by relatively short periods of silence. HDC bats separate pulse and echo in frequency by exploiting information contained in Doppler-shifted echoes arising from their movements relative to background objects and their prey. HDC echolocators are particularly sensitive to amplitude and frequency glints generated by the wings of fluttering insects. We hypothesize that narrowband/CF calls produced at high duty cycle, and combined with neurobiological specializations for processing Doppler-shifted echoes, were essential to the evolution of HDC echolocation because they allowed bats to detect, lock onto and track fluttering targets. This advantage was especially important in habitats with dense vegetation that produce overlapping, time-smeared echoes (i.e. background acoustic clutter). We make four specific, testable predictions arising from this hypothesis.Key words: Chiroptera, calling behaviour, signal design, Yinpterochiroptera, Yangochiroptera, flutter detection, Doppler shift compensation. Fig.1A-C). For the purpose of this paper, we define LDC bats as those producing signals with a duration <25% of their signal period during the search phase of echolocation. Most LDC bats produce echolocation calls with their larynx, although a handful of species in the family Pteropodidae use tongue clicks (Griffin et al., 1958;Yovel et al., 2010).HDC bats avoid auditory masking by separating pulse and echo in frequency, allowing them to broadcast calls and receive echoes at the same time (Schuller, 1974;Schuller, 1977). HDC bats take advantage of information contained in Doppler-shifted echoes generated by the relative movements of bat and target, including acoustic glints generated by the wingbeats of fluttering insects. Echolocation calls of HDC bats consist of a long CF component followed by a brief, downward FM sweep. In some species, the initial portion of the call also contains a short, upward FM sweep (Henson et al., 1987; Jones and Rayner, 1989). Narrowband calls of HDC bats are typically multi-harmonic with the highest signal energy in the second acoustic element (Pye and Roberts, 1970;Schnitzler and Denzinger, 2011). HDC bats emit long duration calls (e.g. 10 to >50ms) relative to their call period ( Fig.1D-F). We operationally define HDC bats as those whose signal durations are ≥25% of...

show abstract

Optimal Localization by Pointing Off Axis

Cited by 123 publications

References 26 publications

Rats track odour trails accurately using a multi-layered strategy with near-optimal sampling

Rats track odour trails accurately using a multi-layered strategy with near-optimal sampling

Echolocating bats use future-target information for optimal foraging

Evolution of high duty cycle echolocation in bats

Contact Info

Product

Resources

About