Escape behaviour in the leopard lizard (Gambelia wislizenii): effects of starting distance and sex

2016 ◽  
Vol 37 (3) ◽  
pp. 320-324 ◽  
Author(s):  
Faelan Jacobson ◽  
Grace Garrison ◽  
Jacob Penner ◽  
João Zecchini Gebin ◽  
Maria Eifler ◽  
...  
Keyword(s):  
Risk Assessment ◽  
Decision Making ◽  
Resource Use ◽  
Environmental Variables ◽  
Flight Distance ◽  
Flight Initiation Distance ◽  
Ecological Role ◽  
Escape Behaviour ◽  
Behavioural Responses ◽  
Flight Initiation

Predation risk influences decision making, escape behaviour, and resource use. Risk assessment and behavioural responses to predation can depend on demographic and environmental factors. We studied the escape behaviour of the long-nosed leopard lizard (Gambelia wislizenii) when approached by a human predator (= “simulated predator”), analysing flight initiation distance (FID) and flight distance (FD) relative to demographic and environmental variables. Starting distance (SD) of the simulated predator and orientation of prey lizards relative to the simulated predator influenced FID, but body size of the prey lizard did not. Sex interacted with SD to affect FID. Females lengthened their FIDs as SD increased, while male FID was unrelated to SD. Flight distance increased with increasing SD. Gambelia wislizenii’s ecological role as an ambush predator may explain their escape behaviour; reproductive status potentially affected the interaction between sex and SD.

scholarly journals European birds adjust their flight initiation distance to road speed limits

2013 ◽  
Vol 9 (5) ◽  
pp. 20130417 ◽  
Author(s):  
Pierre Legagneux ◽  
Simon Ducatez
Keyword(s):  
Habitat Structure ◽  
Territory Size ◽  
Speed Limit ◽  
Vehicle Speed ◽  
Flight Initiation Distance ◽  
Speed Limits ◽  
Behavioural Responses ◽  
Road Speed ◽  
Flight Initiation ◽  
Local Speed

Behavioural responses can help species persist in habitats modified by humans. Roads and traffic greatly affect animals' mortality not only through habitat structure modifications but also through direct mortality owing to collisions. Although species are known to differ in their sensitivity to the risk of collision, whether individuals can change their behaviour in response to this is still unknown. Here, we tested whether common European birds changed their flight initiation distances (FIDs) in response to vehicles according to road speed limit (a known factor affecting killing rates on roads) and vehicle speed. We found that FID increased with speed limit, although vehicle speed had no effect. This suggests that birds adjust their flight distance to speed limit, which may reduce collision risks and decrease mortality maximizing the time allocated to foraging behaviours. Mobility and territory size are likely to affect an individuals' ability to respond adaptively to local speed limits.

Take only pictures, leave only… Cameras influence marmot vigilance but not perceptions of risk

2021 ◽  
Author(s):  
Kenta Uchida ◽  
Albert A. Burkle ◽  
Daniel T. Blumstein
Keyword(s):  
Risk Assessment ◽  
Predation Risk ◽  
Visual Stimulus ◽  
Zoom Lens ◽  
Flight Initiation Distance ◽  
Vulnerable Species ◽  
Species Ranges ◽  
Perceptions Of Risk ◽  
Flight Initiation ◽  
Subsequent Risk

Ecotourism promotes conservation efforts while also allowing for low impact observation of wildlife. Many ecotourists photograph wildlife and photography plays an important role in focusing the public’s attention on nature. Although photography is commonly believed to be a low impact activity, how the visual stimulus of a camera influences wildlife remains unknown. Since animals are known to fear eyes pointed towards them, we predicted that a camera with a large zoom lens would increase animal’s vigilance levels. Using yellow-bellied marmots (Marmota flaviventer) as a mammalian model, and adopting a behavioural approach to identify how marmots responded to cameras, we experimentally quantified vigilance and flight initiation distance towards humans when marmots were approached with and without a camera. While a camera was pointed at an individual, marmots allocated less time to searching predators and increased time to looking at the observer than they did without a camera. However, whether a camera was pointed at a marmot or not had no effect on the distance the marmot flushed. Our results indicated that cameras distracted marmots but did not influence subsequent risk assessment (i.e., flight initiation distance); marmots may be curious about cameras but were not threatened by them. Capturing animals’ attentions reduces searching for predators and may increase the vulnerability to predation. Therefore, regulating photography in locations where predation risk is high or vulnerable species ranges’ overlap with humans may be required to reduce photography’s impact on wildlife.

Risk factors affecting escape behaviour by Puerto Rican Anolis lizards

2006 ◽  
Vol 84 (4) ◽  
pp. 495-504 ◽  
Author(s):  
W.E. Cooper
Keyword(s):  
Risk Factors ◽  
Puerto Rican ◽  
Ground Level ◽  
Flight Initiation Distance ◽  
Running Speed ◽  
Escape Behaviour ◽  
Factors Affecting ◽  
Narrow Temperature Range ◽  
Approach Distance ◽  
Flight Initiation

Approach distance (flight initiation distance) and escape methods depend on predation risk. I studied escape methods and effects of risk factors (temperature, perch height and orientation, conspicuousness) on approach distance in seven Puerto Rican anoles. Approach distance increased as temperature decreased in Anolis gundlachi Peters, 1876, presumably because of decreasing running speed, but not in other species (probably because of narrow temperature range). Perch height and approach distance varied inversely in four arboreal species that escape upward, positively in two grass–bush species that are more conspicuous when higher and flee downward, and were unrelated in cryptic Anolis stratulus Cope, 1861. Approach distance was shortest in cryptic A. stratulus and shorter intraspecifically in three species for partially concealed lizards and at sites providing more cover in two species. Approach distance was shorter for A. gundlachi on vertical than nonvertical perches, suggesting that ease of escape upward affects assessed risk. Escape behaviours have been proposed to vary among anole ecomorphs. Grass–bush species fled downward as proposed, or horizontally near ground level. Contrary to predictions of escape downward by trunk–ground and upward by trunk–crown anoles, all arboreal species escaped upward. Only trunk anoles were proposed to use squirreling, but species from four ecomorphs did as well.

Sex and refuge distance influence escape decision in a Liolaemus lizard when it is approached by a terrestrial predator

Behaviour ◽  
2019 ◽  
Vol 156 (9) ◽  
pp. 909-925 ◽  
Author(s):  
Carla A. Salido ◽  
Natalin S. Vicente
Keyword(s):  
Decision Making ◽  
High Speed ◽  
Sexual Dichromatism ◽  
Flight Initiation Distance ◽  
Sex Influence ◽  
Terrestrial Predator ◽  
Microclimatic Conditions ◽  
Escape Decision ◽  
Escape Speed ◽  
Flight Initiation

Abstract The decision of when and how to escape result crucial for animals because it can result in an interruption to contribute to their fitness. In the present study, we analysed whether speed attack, sex and type of refuge influenced the flight initiation distance (FID) and the closest refuge distance (CRD) in Liolaemus pacha lizards. We also compared the use of different type of refuges. Sex influence both CRD and FID, which would be discussed according to the size of their home range, the escape speed and sexual dichromatism. The interaction between speed and type of refuge used, influence CRD, suggesting that lizards perceived different predation risks. At high-speed approaches, lizards chose the closest refuge, rocks; while at low-speed approaches, lizards chose shrubs as a refuge, mainly the small ones. Lizard’s decision-making is discussed in relation to the refuge protection, their microclimatic conditions and visibility.

scholarly journals Optimal escape theory predicts escape behaviors beyond flight initiation distance: risk assessment and escape by striped plateau lizards Sceloporus virgatus

2009 ◽  
Vol 55 (2) ◽  
pp. 123-131 ◽  
Author(s):  
William E. Cooper
Keyword(s):  
Risk Factors ◽  
Risk Assessment ◽  
Predation Risk ◽  
Flight Initiation Distance ◽  
Risk Levels ◽  
Escape Theory ◽  
Growing Body ◽  
Sceloporus Virgatus ◽  
Escape Behaviors ◽  
Flight Initiation

Abstract Escape theory predicts that flight initiation distance (FID = distance between predator and prey when escape begins) is longer when risk is greater and shorter when escape is more costly. A few tests suggest that escape theory applies to distance fled. Escape models have not addressed stochastic variables, such as probability of fleeing and of entering refuge, but their economic logic might be applicable. Experiments on several risk factors in the lizard Sceloporus virgatus confirmed all predictions for the above escape variables. FID was greater when approach was faster and more direct, for lizards on ground than on trees, for lizards rarely exposed to humans, for the second of two approaches, and when the predator turned toward lizards rather than away. Lizards fled further during rapid and second consecutive approaches. They were more likely to flee when approached directly, when a predator turned toward them, and during second approaches. They were more likely to enter refuge when approached rapidly. A novel finding is that perch height in trees was unrelated to FID because lizards escaped by moving out of sight, then moving up or down unpredictably. These findings add to a growing body of evidence supporting predictions of escape theory for FID and distance fled. They show that two probabilistic aspects of escape are predictable based on relative predation risk levels. Because individuals differ in boldness, the assessed optimal FID and threshold risks for fleeing and entering refuge are exceeded for an increasing proportion of individuals as risk increases.

scholarly journals Vivid birds do not initiate flight sooner despite their potential conspicuousness

2015 ◽  
Vol 61 (4) ◽  
pp. 773-780 ◽  
Author(s):  
Nicholai M. Hensley ◽  
Jonathan P. Drury ◽  
Theodore Garland ◽  
Daniel T. Blumstein
Keyword(s):  
Risk Assessment ◽  
Body Mass ◽  
Experimental Approach ◽  
Flight Initiation Distance ◽  
Phylogenetic Relatedness ◽  
Explained Variation ◽  
Flight Initiation

Abstract The distance from an approaching threat at which animals initiate flight -- flight-initiation distance (FID) -- is a sensitive metric of variation in risk, but the effects on FID associated with the risk of possessing highly detectable external coloration are unknown. We tested whether variation in the degree of plumage vividness in birds explained variation in flight-initiation distance. After controlling for body mass, the distance at which the experimental approach began, and phylogenetic relatedness, plumage vividness was not a predictor of FID. Contrary to the expectation that vividness affects risk, and therefore risk assessment, these results suggest that birds do not compensate for greater visual conspicuousness by fleeing sooner from approaching threats.

Conspicuousness and vestigial escape behaviour by two dendrobatid frogs, Dendrobates auratus and Oophaga pumilio

Behaviour ◽  
2009 ◽  
Vol 146 (3) ◽  
pp. 325-349 ◽  
Author(s):  
Janalee Caldwell ◽  
Laurie Vitt ◽  
William Cooper
Keyword(s):  
Defensive Behavior ◽  
Close Approach ◽  
Flight Initiation Distance ◽  
Escape Behaviour ◽  
Predator Prey ◽  
Poison Frogs ◽  
Oophaga Pumilio ◽  
Approach Speed ◽  
Dendrobates Auratus ◽  
Flight Initiation

AbstractAposematic prey are thought to move slowly and openly near predators, but exhibit reduced escape behaviour. We studied conspicuousness and escape by aposematic poison frogs (Dendrobates auratus and Oophaga pumilio). In circles of leaf litter, observers detected poison frogs quickly. Flight initiation distance (FID, predator-prey distance when escape begins) increases with approach speed in non-cryptic palatable prey, but not for frogs in clearings, which permitted close approach. On trails frogs moved slowly into forest and FID in D. auratus increased with approach speed. Distance from cover and handling exposing predators to distastefulness may account for greater reliance on aposematism in clearings. We observed responses to a simulated predator (stick with painted face) in three conditions: not approached, approached, and touched. Latency to hop and time to exit circles decreased and exit from circles was directed further away from the approach path in the order not approached, approached, touched. Oophaga pumilio changed directions less when approached than not; many exhibited no escape behaviour. Aposematic dendrobatids move slowly near predators, but retain risk-assessment mechanisms due to occasional predation. Differences in escape between dendrobatids and palatable Craugastor frogs suggest that dendrobatid defensive behavior may have been molded to maximize the effectiveness of aposematism.

scholarly journals Escape behaviour of aposematic (Oophaga pumilio) and cryptic (Craugastor sp.) frogs in response to simulated predator approach

2017 ◽  
Vol 33 (2) ◽  
pp. 165-169 ◽  
Author(s):  
Annelise Blanchette ◽  
Noémi Becza ◽  
Ralph A. Saporito
Keyword(s):  
Flight Initiation Distance ◽  
Warning Signals ◽  
Escape Behaviour ◽  
Antipredator Strategies ◽  
Oophaga Pumilio ◽  
Flight Initiation

Abstract:Crypsis and aposematism are common antipredator strategies that can each be coupled with behaviours that maximize predator deterrence or avoidance. Cryptic animals employ camouflage to conceal themselves within their environment and generally rely on immobility to avoid detection by predators. Alternatively, aposematic animals tend to rely on an association between conspicuous colouration and secondary defence to deter potential predators, and tend to exhibit slow movements in response to predators. The goal of the present study was to determine how cryptic Craugastor sp. and aposematic Oophaga pumilio respond to simulated human and bird model predators. Oophaga pumilio responded more often with movement to both the human (17/22) and bird (9/25) predators than Craugastor sp. (human: 2/21; bird: 0/21). The increased movement resulted in a greater average flight initiation distance, latency to move, and distance fled in O. pumilio. These findings suggest that cryptic Craugastor sp. rely on immobility to avoid detection, whereas aposematic O. pumilio utilize movement, possibly as a mechanism to increase the visibility of their warning signals to potential predators. Furthermore, O. pumilio exhibited greater movement in response to humans, suggesting that they actively avoid trampling by large threats, rather than considering them predators.

Effects of sex and microhabitat structure on escape behaviour in the diurnal gecko Gonatodes albogularis

2016 ◽  
Vol 66 (1) ◽  
pp. 31-47 ◽  
Author(s):  
Moisés E. Domínguez-López ◽  
Francisco J. Diego-Rasilla ◽  
Ángela M. Ortega-León
Keyword(s):  
Tropical Dry Forest ◽  
Structural Complexity ◽  
Dry Forest ◽  
Microhabitat Use ◽  
Flight Initiation Distance ◽  
Escape Behaviour ◽  
Escape Theory ◽  
Microhabitat Structure ◽  
The Cost ◽  
Flight Initiation

Flight initiation distance is defined as the distance between a prey and an approaching predator when the prey starts to flee. Escape theory predicts that the optimal flight initiation distance is the distance where predation risk rises to the point at which it equals the cost of fleeing. Therefore, staying close to refuge and occupying microhabitats with more abundant shelters (i.e., crevices or shrubs) may allow lizards to have shorter flight initiation distance. By simulating an approaching predator, we studied the effect of microhabitat structural complexity on escape behaviour, in particular, the distance fled before stopping and final distance (predator-prey distance when the prey stops fleeing), of a small diurnal tropical gecko, the yellow-headed geckoGonatodes albogularisinhabiting a tropical dry forest. The findings indicate that refuge abundance and distance to the nearest potential refuge influence escape behaviour ofG. albogularis. In addition, we found sex differences in escape behaviour which are not explained by microhabitat use. Females had longer flight initiation distance but shorter distance fled, and longer final distances than males.

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