Differences in Patch Use Behavior Between an Urban and Rural Species: Effects of Distance from Shelter and Wing Molt-Gaps

2009 ◽  
Vol 55 (4) ◽  
pp. 345-357
Author(s):  
Ido Tsurim ◽  
Zvika Abramsky ◽  
Burt P. Kotler
Keyword(s):  
Predation Risk ◽  
Wing Surface ◽  
Urban Birds ◽  
House Sparrows ◽  
Pronounced Increase ◽  
Bird Populations ◽  
Risk Of Predation ◽  
Predation Costs ◽  
Use Behavior ◽  
The Cost

It has been suggested that urban bird populations and communities are controlled by bottom-up mechanisms because predation costs are lower in urban than in non-urban habitats. We hypothesized that urban birds are less sensitive to variations in the cost of predation than non-urban birds. We predicted that the house sparrow, a widespread urban species, is less sensitive to variations in predation risk, while foraging, than its rural (less urban) congener, the Spanish sparrow. We quantified foraging behavior of these species, as affected by the proximity to shelter, in large outdoor aviaries. We then clipped feathers from the birds' wings to manipulate escape ability and increase predation risk. We predicted that birds experience increasing predation risk with increasing distance from shelter, and that reduced wing surface increases the birds' sensitivity to risk of predation with respect to distance from shelter. Both species displayed increasing giving-up densities in seed trays with increasing distance from shelter, indicating that foraging costs increase with distance from shelter. As predicted, the two species differed in their response to proximity of shelter: we concluded that house sparrows experienced a less pronounced increase in perceived predation cost with increasing distance from shelter than did Spanish sparrows. Contrary to our prediction, wing surface reduction had no effect on seed tray utilization. Therefore, it appears that, when feeding in patches at distances from shelter, as used in the present study, the cost of predation affects foraging and micro-habitat use in Spanish sparrows more than in house sparrows.

scholarly journals Detection of predator cues alters mating tactics in male wolf spiders

Behaviour ◽  
2014 ◽  
Vol 151 (5) ◽  
pp. 573-590 ◽  
Author(s):  
Dustin J. Wilgers ◽  
Daniel Wickwire ◽  
Eileen A. Hebets
Keyword(s):  
Predation Risk ◽  
Good Condition ◽  
Wolf Spider ◽  
Alternative Mating Tactics ◽  
Mating Tactics ◽  
Mating Tactic ◽  
Risk Of Predation ◽  
Courtship Activity ◽  
The Cost ◽  
Perceived Predation Risk

Males of the wolf spider, Rabidosa punctulata, exhibit condition-dependent alternative mating tactics, whereby small, poor condition males engage in multimodal courtship while large, good condition males adopt a direct mount tactic that forgoes courtship. This study explores the possibility that tactic-specific costs can help explain this unintuitive pattern of mating tactic expression. Specifically, we hypothesize that courtship signaling is costly with respect to eavesdropping by predators and that males can alter their tactic expression based upon the perceived environmental predation risk. We test this by first examining the risk of predation associated with different mating tactics. We use a co-occurring predatory heterospecific, R. rabida as our predator. We found support for the prediction that courting R. punctulata males tended to be attacked more often than non-courting males, and the likelihood of being attacked was best predicted by courtship activity. Given this documented cost, we hypothesized that R. punctulata males would adjust their mating tactic based upon perceived predation risk. In a second experiment, we manipulated perceived predation risk by providing R. punctulata males with different female silk cues (conspecific; predatory heterospecific; conspecific + predatory heterospecific) and examined mating tactic expression. In support of our hypothesis, males were more likely to adopt the direct mount tactic in the presence of predatory heterospecific or mixed silk cues and were more likely to court in the presence of conspecific cues. These results support the hypothesis that the cost of predation from eavesdroppers may influence the evolution and expression of male alternative mating tactics in R. punctulata.

Do changes in reef habitats influence relative predation risk on the juvenile Australasian spiny lobster, Jasus edwardsii (Hutton, 1875)?

Crustaceana ◽  
2015 ◽  
Vol 88 (7-8) ◽  
pp. 839-856 ◽  
Author(s):  
J. Hesse ◽  
J. A. Stanley ◽  
A. G. Jeffs
Keyword(s):  
Predation Risk ◽  
Spatial Scales ◽  
Spiny Lobster ◽  
Habitat Type ◽  
Small Spatial Scale ◽  
Important Species ◽  
Early Juvenile ◽  
Risk Of Predation ◽  
Jasus Edwardsii ◽  
Commercially Important

Kelp habitats are in decline in many temperate coastal regions of the world due to climate change and expansion of populations of grazing urchins. The loss of kelp habitat may influence the vulnerability to predators of the juveniles of commercially important species. In this study relative predation rates for kelp versus barren reef habitat were measured for early juvenile Australasian spiny lobster, Jasus edwardsii (Hutton, 1875), on the northeastern coast of New Zealand using tethering methods. Variation in assemblages of predators over small spatial scales appeared to be more important for determining the relative predation of lobsters, regardless of habitat type. Therefore, the assessment of relative predation risk to early juvenile lobsters between kelp and barren habitats will require more extensive sampling at a small spatial scale, as well as a specific focus on sampling during crepuscular and nocturnal periods when these lobsters are most at risk of predation.

Behavioural responses of voles to simulated risk of predation by a native and an alien mustelid: an odour manipulation experiment

2010 ◽  
Vol 37 (4) ◽  
pp. 273 ◽  
Author(s):  
Karen Fey ◽  
Peter B. Banks ◽  
Hannu Ylönen ◽  
Erkki Korpimäki
Keyword(s):  
Baltic Sea ◽  
Predation Risk ◽  
Myodes Glareolus ◽  
The Baltic Sea ◽  
Short Term ◽  
Behavioural Responses ◽  
Alien Predator ◽  
Risk Of Predation ◽  
The Baltic ◽  
The Impact

Context. Potential mammalian prey commonly use the odours of their co-evolved predators to manage their risks of predation. But when the risk comes from an unknown source of predation, odours might not be perceived as dangerous, and anti-predator responses may fail, except possibly if the alien predator is of the same archetype as a native predator. Aims. In the present study we examined anti-predator behavioural responses of voles from the outer archipelagos of the Baltic Sea, south-western Finland, where they have had no resident mammalian predators in recent history. Methods. We investigated responses of field voles (Microtus agrestis) to odours of native least weasels (Mustela nivalis) and a recently invading alien predator, the American mink (Mustela vison), in laboratory. We also studied the short-term responses of free-ranging field voles and bank voles (Myodes glareolus) to simulated predation risk by alien mink on small islands in the outer archipelago of the Baltic Sea. Key results. In the laboratory, voles avoided odour cues of native weasel but not of alien mink. It is possible that the response to mink is a context dependent learned response which could not be induced in the laboratory, whereas the response to weasel is innate. In the field, however, voles reduced activity during their normal peak-activity times at night as a response to simulated alien-mink predation risk. No other shifts in space use or activity in safer microhabitats or denser vegetation were apparent. Conclusions. Voles appeared to recognise alien minks as predators from their odours in the wild. However, reduction in activity is likely to be only a short-term immediate response to mink presence, which is augmented by longer-term strategies of habitat shift. Because alien mink still strongly suppresses vole dynamics despite these anti-predator responses, we suggest that behavioural naiveté may be the primary factor in the impact of an alien predator on native prey. Implications. Prey naiveté has long been considered as the root cause of the devastating impacts of alien predators, whereby native prey simply fail to recognise and respond to the novel predation risk. Our results reveal a more complex form of naiveté whereby native prey appeared to recognise alien predators as a threat but their response is ultimately inadequate. Thus, recognition alone is unlikely to afford protection for native prey from alien-predator impacts. Thus, management strategies that, for example, train prey in recognition of novel threats must induce effective responses if they are expected to succeed.

scholarly journals The cost of safety: Refuges increase the impact of predation risk in aquatic systems

Ecology ◽  
2013 ◽  
Vol 94 (3) ◽  
pp. 573-579 ◽  
Author(s):  
John L. Orrock ◽  
Evan L. Preisser ◽  
Jonathan H. Grabowski ◽  
Geoffrey C. Trussell
Keyword(s):  
Predation Risk ◽  
Aquatic Systems ◽  
The Cost ◽  
The Impact

scholarly journals Predation Risk by Gastronomic Boom - Case Peru

2018 ◽  
Vol 11 (1) ◽  
pp. 100-103
Author(s):  
Aldo Alvarez-Risco ◽  
Jaime Delgado-Zegarra ◽  
Jaime A. Yáñez ◽  
Santiago Diaz-Risco ◽  
Shyla Del-Aguila-Arcentales
Keyword(s):  
Natural Resources ◽  
Predation Risk ◽  
Environmental Sustainability ◽  
Natural Sources ◽  
Risk Of Predation ◽  
Significant Damage

Abstract The growth of tourism to Peru and the gastronomic boom with millions of people looking to taste Peruvian food is resulting in a risk of predation of natural sources necessary to make these dishes. The focus in only obtaining these ingredients can generate significant damage to the Peruvian biodiversity, so stakeholders need to develop strategies to avoid predation due to the gastronomic boom. Citizens and visitors need to play a role in protecting the natural resources and contributing to environmental sustainability.

scholarly journals The landscape of fear conceptual framework: definition and review of current applications and misuses

2017 ◽  
Author(s):  
Sonny S Bleicher
Keyword(s):  
Conceptual Framework ◽  
Predation Risk ◽  
Cost Benefit Analysis ◽  
Cost Benefit ◽  
Future Research ◽  
Common Framework ◽  
Dimensional Distribution ◽  
History Of ◽  
Energetic State ◽  
The Cost

Landscapes of Fear (LOF), the spatially explicit distribution of perceived predation risk as seen by a population, is increasingly cited in ecological literature and has become a frequently used “buzz-word”. With the increase in popularity, it became necessary to clarify the definition for the term, suggest boundaries and propose a common framework for its use. The LOF, as a progeny of the “ecology of fear” conceptual framework, defines fear as the strategic manifest of the cost-benefit analysis of food and safety tradeoffs. In addition to direct predation risk, the LOF is affected by individuals’ energetic-state, inter- and intra-specific competition and is constrained by the evolutionary history of each species. Herein, based on current applications of the LOF conceptual framework, I suggest the future research in this framework will be directed towards: (1) finding applied management uses as a trait defining a population’s habitat-use and habitat-suitability; (2) studying multi-dimensional distribution of risk-assessment through time and space; (3) studying variability between individuals within a population; and (4) measuring eco-neurological implications of risk as a feature of environmental heterogeneity.

Hiding time of the hermit crab Calcinus californiensis: observations from different shell types

2015 ◽  
Vol 93 (7) ◽  
pp. 559-565 ◽  
Author(s):  
Carlos Enrique Chávez-Solís ◽  
Guillermina Alcaraz
Keyword(s):  
Water Column ◽  
Potential Risk ◽  
Hermit Crab ◽  
Hermit Crabs ◽  
Resource Value ◽  
Risk Of Predation ◽  
Potential Risks ◽  
Time Required ◽  
The Cost ◽  
Return To Activity

Hermit crabs respond to predators by hiding in their shells. However, retraction may cause the crab to lose hold of the rock and fall through the water column, and the crab may land with the shell aperture in a different orientation. When the shell is aperture down, hermit crabs return to activity by moving their bodies forward and placing their legs on the ground. In contrast, when the shell is aperture up, crabs need to perform a righting maneuver by extending part of their bodies out of the shell, which makes them more vulnerable to predation. The main goal of this study was to examine the hiding time of the hermit crab Calcinus californiensis Bouvier, 1898 in different shell species under these two different situations to better understand the conflict between the cost of staying in hiding and the risk of predation. The study was conducted in rocky tide pools using seven different shell types that reflect different predator protection and resource value to the crab (based on previous studies). We measured the time required to perform the righting maneuver as a measure of the potential risk incurred when returning to activity. The hiding time with the shell aperture down was not affected by shell species. The requirement to carry out a righting maneuver lengthened the hiding time, which varied in the different shell species according to the time required to recover the natural position. The potential risks associated with the righting time, the protection offered by the shells, and the resource value played an important role in the hiding time of the crabs using different shells. This study shows that hermit crabs are aware of the attributes of the shell and use this information to make decisions about how long to stay hidden after being threatened.

scholarly journals Prey synchronize their vigilant behaviour with other group members

2007 ◽  
Vol 274 (1615) ◽  
pp. 1287-1291 ◽  
Author(s):  
Olivier Pays ◽  
Pierre-Cyril Renaud ◽  
Patrice Loisel ◽  
Maud Petit ◽  
Jean-François Gerard ◽  
...  
Keyword(s):  
Predation Risk ◽  
Group Size ◽  
Prey Species ◽  
Group Members ◽  
The Individual ◽  
The Cost ◽  
Group Member

It is generally assumed that an individual of a prey species can benefit from an increase in the number of its group's members by reducing its own investment in vigilance. But what behaviour should group members adopt in relation to both the risk of being preyed upon and the individual investment in vigilance? Most models assume that individuals scan independently of one another. It is generally argued that it is more profitable for each group member owing to the cost that coordination of individual scans in non-overlapping bouts of vigilance would require. We studied the relationships between both individual and collective vigilance and group size in Defassa waterbuck, Kobus ellipsiprymnus defassa , in a population living under a predation risk. Our results confirmed that the proportion of time an individual spent in vigilance decreased with group size. However, the time during which at least one individual in the group scanned the environment (collective vigilance) increased. Analyses showed that individuals neither coordinated their scanning in an asynchronous way nor scanned independently of one another. On the contrary, scanning and non-scanning bouts were synchronized between group members, producing waves of collective vigilance. We claim that these waves are triggered by allelomimetic effects i.e. they are a phenomenon produced by an individual copying its neighbour's behaviour.

Developmental costs of yellow colouration in fire salamanders and experiments to test the efficiency of yellow as a warning colouration

2020 ◽  
Vol 41 (3) ◽  
pp. 373-385 ◽  
Author(s):  
Barbara A. Caspers ◽  
E. Tobias Krause ◽  
Isabelle Hermanski ◽  
Christopher Wiesbrock ◽  
Friedrich-Wilhelm Kastrup ◽  
...  
Keyword(s):  
Predation Risk ◽  
Carabid Beetles ◽  
Colour Pattern ◽  
Natural Habitats ◽  
Yellow Colour ◽  
Risk Of Predation ◽  
Fire Salamander ◽  
Food Conditions ◽  
In Fire ◽  
Salamander Larvae

Abstract Warning colouration reduces predation risk by signalling or mimicking the unpleasantness of prey and therefore increases survival. We tested in two experiments the evolutionary costs and benefits of the yellow colour pattern in fire salamanders (Salamandra salamandra), which display a yellow/black colour pattern usually associated with toxic alkaloids. Our first experiment aimed to test whether the development of colouration is condition dependent and thus related to developmental costs, i.e. influenced by resource availability during the developmental process. Therefore, we reared fire salamander larvae under different nutritional conditions and compared the relative amount of yellow they developed after metamorphosis. Fire salamander larvae reared under limited food conditions had a lower proportion of yellow following metamorphosis than control larvae reared under superior food conditions. In a second experiment we tested whether the proportion of yellow has an impact on the risk of being attacked using artificial models. We tested, in salamander-free and salamander-occupied natural habitats, whether artificial clay models with different proportions of yellow and black receive different attack rates from potential predators (birds, mammals, insects). In clay models the proportion of yellow and the site had a significant effect on predation risk. Models with larger amounts of yellow had fewer bite marks from predators such as carabid beetles and birds, but only in sympatry with salamanders. In conclusion, the early expression of conspicuous colouration seems to be condition dependent and therefore potentially costly. Furthermore, the yellow colouration of fire salamanders act as a signal that potentially reduces their risk of being attacked by predators. Thus, the yellow colouration of fire salamanders seems to represent an adaptive trait that reduces the risk of predation, which can be expressed in higher quantity by individuals of a certain condition.

scholarly journals Risk of social colours in an agamid lizard: implications for the evolution of dynamic signals

2019 ◽  
Vol 15 (5) ◽  
pp. 20190207 ◽  
Author(s):  
Madhura S. Amdekar ◽  
Maria Thaker
Keyword(s):  
Natural Selection ◽  
Social Interactions ◽  
Predation Risk ◽  
Colour Pattern ◽  
Male Aggression ◽  
Visual Systems ◽  
In The Wild ◽  
Predation Costs ◽  
Colour Patterns ◽  
Ecological Cost

The forces of sexual and natural selection are typically invoked to explain variation in colour patterns of animals. Although the benefits of conspicuous colours for social signalling are well documented, evidence for their ecological cost, especially for dynamic colours, remains limited. We examined the riskiness of colour patterns of Psammophilus dorsalis , a species in which males express distinct colour combinations during social interactions. We first measured the conspicuousness of these colour patterns on different substrates based on the visual systems of conspecifics and predators (bird, snake, canid) and then quantified actual predation risk on these patterns using wax/polymer lizard models in the wild. The black and red male state exhibited during courtship was the most conspicuous to all visual systems, while the yellow and orange male aggression state and the brown female colour were least conspicuous. Models bearing the courtship colour pattern experienced the highest predator attacks, irrespective of the substrate they were placed on. Thus, social colours of males are not only conspicuous but also risky. Using physiological colours to shift in and out of conspicuous states may be an effective evolutionary solution to balance social signalling benefits with predation costs.

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