scholarly journals California scrub-jays reduce visual cues available to potential pilferers by matching food colour to caching substrate

2017 ◽  
Vol 13 (7) ◽  
pp. 20170242
Author(s):  
Laura A. Kelley ◽  
Nicola S. Clayton

Some animals hide food to consume later; however, these caches are susceptible to theft by conspecifics and heterospecifics. Caching animals can use protective strategies to minimize sensory cues available to potential pilferers, such as caching in shaded areas and in quiet substrate. Background matching (where object patterning matches the visual background) is commonly seen in prey animals to reduce conspicuousness, and caching animals may also use this tactic to hide caches, for example, by hiding coloured food in a similar coloured substrate. We tested whether California scrub-jays ( Aphelocoma californica ) camouflage their food in this way by offering them caching substrates that either matched or did not match the colour of food available for caching. We also determined whether this caching behaviour was sensitive to social context by allowing the birds to cache when a conspecific potential pilferer could be both heard and seen (acoustic and visual cues present), or unseen (acoustic cues only). When caching events could be both heard and seen by a potential pilferer, birds cached randomly in matching and non-matching substrates. However, they preferentially hid food in the substrate that matched the food colour when only acoustic cues were present. This is a novel cache protection strategy that also appears to be sensitive to social context. We conclude that studies of cache protection strategies should consider the perceptual capabilities of the cacher and potential pilferers.

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e4451 ◽  
Author(s):  
Katharina F. Brecht ◽  
Ljerka Ostojić ◽  
Edward W. Legg ◽  
Nicola S. Clayton

Previous research has suggested that videos can be used to experimentally manipulate social stimuli. In the present study, we used the California scrub-jays’ cache protection strategies to assess whether video playback can be used to simulate conspecifics in a social context. In both the lab and the field, scrub-jays are known to exhibit a range of behaviours to protect their caches from potential pilferage by a conspecific, for example by hiding food in locations out of the observer’s view or by re-caching previously made caches once the observer has left. Here, we presented scrub-jays with videos of a conspecific observer as well as two non-social conditions during a caching period and assessed whether they would cache out of the observer’s “view” (Experiment 1) or would re-cache their caches once the observer was no longer present (Experiment 2). In contrast to previous studies using live observers, the scrub-jays’ caching and re-caching behaviour was not influenced by whether the observer was present or absent. These findings suggest that there might be limitations in using video playback of social agents to mimic real-life situations when investigating corvid decision making.


2009 ◽  
Vol 5 (5) ◽  
pp. 583-585 ◽  
Author(s):  
Gert Stulp ◽  
Nathan J. Emery ◽  
Simon Verhulst ◽  
Nicola S. Clayton

Western scrub-jays ( Aphelocoma californica ) engage in a variety of cache-protection strategies to reduce the chances of cache theft by conspecifics. Many of these strategies revolve around reducing visual information to potential thieves. This study aimed to determine whether the jays also reduce auditory information during caching. Each jay was given the opportunity to cache food in two trays, one of which was filled with small pebbles that made considerable noise when cached in (‘noisy’ tray), whereas the other one contained soil that made little detectable noise when cached in (‘quiet’ tray). When the jays could be heard, but not seen, by a competitor, they cached proportionally less food items in the ‘noisy’ substrate than when they cached alone in the room, or when they could be seen and heard by competitors. These results suggest that western scrub-jays know when to conceal auditory information, namely when a competitor cannot see but can hear the caching event.


Author(s):  
Dori B. Reissman ◽  
Maryann M. D’Alessandro ◽  
Lisa Delaney ◽  
John Piacentino

This chapter describes disaster worker protection strategies and health surveillance activities in terms of temporal phases to address disaster safety management before, during, and after a disaster event. The protective strategies discussed in the chapter integrate assessments of on-scene hazards and health or safety impacts and require pre-event planning and coordination across multiple entities. The chapter also addresses the integration of physical, psychological and behavioral health approaches. The chapter addresses the complexities of hazard assessment and control, worker education and training, worker illness and injury surveillance, and access to healthcare services, along with a box on community preparedness. These activities are performed by diverse groups of occupational and environmental health professionals. Various illustrative examples are presented to describe how basic concepts of protection and medical evaluation are applied in specific situations. The U.S. federal system for protecting disaster rescue and recovery workers is described in detail.


Author(s):  
John D. Horner ◽  
Bartosz J. Płachno ◽  
Ulrike Bauer ◽  
Bruno Di Giusto

The ability to attract prey has long been considered a universal trait of carnivorous plants. We review studies from the past 25 years that have investigated the mechanisms by which carnivorous plants attract prey to their traps. Potential attractants include nectar, visual, olfactory, and acoustic cues. Each of these has been well documented to be effective in various species, but prey attraction is not ubiquitous among carnivorous plants. Directions for future research, especially in native habitats in the field, include: the qualitative and quantitative analysis of visual cues, volatiles, and nectar; temporal changes in attractants; synergistic action of combinations of attractants; the cost of attractants; and responses to putative attractants in electroantennograms and insect behavioral tests.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Caitlin S. Mallory ◽  
Kiah Hardcastle ◽  
Malcolm G. Campbell ◽  
Alexander Attinger ◽  
Isabel I. C. Low ◽  
...  

AbstractNeural circuits generate representations of the external world from multiple information streams. The navigation system provides an exceptional lens through which we may gain insights about how such computations are implemented. Neural circuits in the medial temporal lobe construct a map-like representation of space that supports navigation. This computation integrates multiple sensory cues, and, in addition, is thought to require cues related to the individual’s movement through the environment. Here, we identify multiple self-motion signals, related to the position and velocity of the head and eyes, encoded by neurons in a key node of the navigation circuitry of mice, the medial entorhinal cortex (MEC). The representation of these signals is highly integrated with other cues in individual neurons. Such information could be used to compute the allocentric location of landmarks from visual cues and to generate internal representations of space.


2019 ◽  
Vol 97 (5) ◽  
pp. 488-494 ◽  
Author(s):  
Riley R. Lawson ◽  
Dillon T. Fogarty ◽  
Scott R. Loss

Predator–prey interactions influence behaviors and life-history evolution for both predator and prey species and also have implications for biodiversity conservation. A fundamental goal of ecology is to clarify mechanisms underlying predator–prey interactions and dynamics. To investigate the role of predator sensory mechanisms in predator–prey interactions, specifically in predator detection of prey, we experimentally evaluated importance of visual and olfactory cues for an apex predator, the coyote (Canis latrans Say, 1823). Unlike similar studies, we examined use of sensory cues in a field setting. We used trail cameras and four replicated treatments — visual only, olfactory only, visual and olfactory combined, and a control — to quantify coyote visitation rates in North American deciduous forests during fall 2016. Coyote visitation was greatest for olfactory-only and visual-only cues, followed by the combined olfactory–visual cue; all cues attracted more coyotes than the control (i.e., olfactory = visual > olfactory–visual > control). Our results suggest this apex predator uses both olfactory and visual cues while foraging for prey. These findings from a field study of free-roaming coyotes increase understanding of predator foraging behavior, predator–prey interactions, and sensory ecology. Our study also suggests future directions for field evaluations of the role of different sensory mechanisms in predator foraging and prey concealment behaviors.


1996 ◽  
Vol 74 (12) ◽  
pp. 2248-2253 ◽  
Author(s):  
Lamar A. Windberg

Individual coyotes (Canis latrans) are infrequently captured within their familiar areas of activity. Current hypotheses are that the differential capture vulnerability may involve neophobia or inattentiveness. To assess the effect of familiarity, I measured coyote responsiveness to sensory cues encountered in familiar and novel settings. Seventy-four captive coyotes were presented with visual and olfactory stimuli in familiar and unfamiliar 1-ha enclosures. The visual stimuli were black or white wooden cubes of three sizes (4, 8, and 16 cm per side). The olfactory stimuli were fatty acid scent, W-U lure (trimethylammonium decanoate plus sulfide additives), and coyote urine and liquefied feces. Overall, coyotes were more responsive to stimuli during exploration in unfamiliar than in familiar enclosures. None of 38 coyotes that responded were neophobic toward the olfactory stimuli. The frequency of coyote response, and the resulting degrees of neophobia, did not differ between the black and white visual stimuli. Regardless of context, the largest visual stimuli were recognized at the greatest distance and evoked the strongest neophobic response. A greater proportion of coyotes were neophobic toward the small and medium-sized stimuli in familiar than in unfamiliar enclosures. This study demonstrated that when encountered in familiar environments, visual cues are more likely to elicit neophobic responses by coyotes than are olfactory stimuli.


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