scholarly journals Winter activity patterns of American martens (Martes americana): rejection of the hypothesis of thermal-cost minimization

1997 ◽  
Vol 75 (5) ◽  
pp. 812-816 ◽  
Author(s):  
Gary S. Drew ◽  
John A. Bissonette
Keyword(s):  
Predation Risk ◽  
Cost Minimization ◽  
Activity Patterns ◽  
Martes Americana ◽  
Diel Activity ◽  
Foraging Efficiency ◽  
Behavioral Strategies ◽  
Vulnerability Hypothesis ◽  
Log Linear ◽  
American Martens

Despite their temperate to subarctic geographic range, American martens (Martes americana) possess a thermally inefficient morphology. The lack of morphological adaptations for reducing thermal costs suggests that marten may use behavioral strategies to optimize thermal budgets. During the winters of 1989–1990 and 1990–1991, we radio-collared and monitored the diel activity of 7 martens. A log-linear model suggested that the presence or absence of light was the only factor associated with marten activity patterns (p < 0.001). A regression of the percentage of active fixes on ambient temperature failed to detect an association (b = −4.45, p = 0.084, n = 12). Contents of marten scats suggested that their activity was consistent with the prey-vulnerability hypothesis. While martens must balance multiple life requisites, their activity patterns suggest that they accept increased thermal costs in order to increase foraging efficiency. However, the nocturnal activity of martens during winter was also consistent with the hypothesis that they may be able to limit their own exposure to predation risk. The nocturnal habits of Newfoundland martens in the winter were consistent with the hypothesis of avoidance of predation risk.

scholarly journals Nonconsumptive Effects of Predation and Impaired Chemosensory Risk Assessment on an Aquatic Prey Species

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Chris K. Elvidge ◽  
Grant E. Brown
Keyword(s):  
Risk Assessment ◽  
Predation Risk ◽  
Visual Information ◽  
Activity Patterns ◽  
Diel Activity ◽  
Nonconsumptive Effects ◽  
Diel Activity Patterns ◽  
Foraging Tactics ◽  
Transplant Experiments ◽  
Behavioural Strategies

Weak levels of acidity impair chemosensory risk assessment by aquatic species which may result in increased predator mortalities in the absence of compensatory avoidance mechanisms. Using replicate populations of wild juvenile Atlantic salmon (Salmo salar) in neutral and acidic streams, we conducted a series of observational studies and experiments to identify differences in behaviours that may compensate for the loss of chemosensory information on predation risk. Comparing the behavioural strategies of fish between neutral and acidic streams may elucidate the influence of environmental degradation on nonconsumptive effects (NCEs) of predation. Salmon in acidic streams are more active during the day than their counterparts in neutral streams, and are more likely to avoid occupying territories offering fewer physical refugia from predators. Captive cross-population transplant experiments indicate that at equal densities, salmon in acidic streams do not demonstrate relative decreases in growth rate as a result of their different behavioural strategies. Instead, altering diel activity patterns to maximize visual information use and occupying relatively safer territories appear sufficient to offset increased predation risk in acidic streams. Additional strategies such as elevated foraging rates during active periods or adopting riskier foraging tactics are necessary to account for the observed similarities in growth rates.

Predation risk increases intraspecific heterogeneity in white-tailed deer diel activity patterns

2020 ◽  
Author(s):  
Daniel A Crawford ◽  
L Mike Conner ◽  
Gail Morris ◽  
Michael J Cherry
Keyword(s):  
Predation Risk ◽  
Prey Species ◽  
Activity Patterns ◽  
Camera Traps ◽  
Diel Activity ◽  
Intraspecific Interactions ◽  
Temporal Partitioning ◽  
Diel Activity Patterns ◽  
Predator Exclusion ◽  
And Control

Abstract Prey species often mitigate predation risk through alteration of spatiotemporal diel activity patterns whereby prey access high-quality resources in risky areas during predator downtimes. However, dominance hierarchies exist in some prey species, and temporal partitioning is a mechanism thought to reduce aggressive intraspecific interactions. How demographic-specific responses to predation risk influence intraspecific temporal partitioning in prey are largely unknown and could be key to understanding the effects of predators on intraspecific interactions in prey. To assess the effects of predation risk on intraspecific interactions in white-tailed deer (Odocoileus virginianus), we monitored deer diel activity during the fawning season in four pairs of predator exclusion and control plots (~40 ha) from 2015 to 2018 using 16 camera traps. We examined the effect of predation risk on diel activity of males, females, and nursery groups by comparing the within-group coefficient of activity overlap (d̂) across predator exclusion and control plots. We then examined within-treatment activity overlap between groups in the predator exclosure and control plots. All groups maintained different diel activity patterns in safe and risky areas. Unconstrained by predation risk, all groups behaved more similarly, and interspecific group overlap was greater in the predator exclusion plots than control plots. Male-nursery group overlap exhibited the strongest treatment effect, increasing 24% in predator exclusion plots (d̂ = 0.91, confidence interval [CI]: 0.87–0.95) relative to control plots (d̂ = 0.67, CI: 0.57–0.76). Our results suggest predators increase heterogeneity in prey behavior and may be important drivers of behavioral processes, such as temporal partitioning, that minimize antagonistic intraspecific interactions of prey.

scholarly journals Diel patterns of foraging and microhabitat use by sympatric rainbow trout and bull trout: implications for adaptive differentiation and instream flow assessment

2021 ◽  
Author(s):  
Sean M. Naman ◽  
Jordan S Rosenfeld ◽  
Alecia S. Lannan
Keyword(s):  
Rainbow Trout ◽  
Habitat Use ◽  
Predation Risk ◽  
Habitat Suitability ◽  
Diel Activity ◽  
Foraging Efficiency ◽  
Bull Trout ◽  
Flow Management ◽  
Habitat Suitability Models ◽  
Trade Offs

Salmonids make flexible and adaptive trade-offs between foraging efficiency and predation risk that result in variable patterns of diel activity and habitat use. However, it remains unclear: (1) how patterns differ among salmonid species; and (2) how this affects the interpretation of habitat suitability models that inform instream flow management. We combined snorkel observations with experimental additions of cover to investigate how predation risk, cover, and bioenergetics affect diel activity and habitat use patterns by sympatric rainbow trout and bull trout in the Skagit River, BC, Canada. Both species foraged primarily at dusk, supporting the well-described trade-off between foraging efficiency and predation risk. However, only rainbow trout responded to cover additions, suggesting that risk tolerance and the nature of foraging-predation risk trade-offs differ between species. Diel shifts in activity and habitat use also substantially altered predictions of habitat suitability models, with potentially large consequences for flow management.

scholarly journals Vigilance and predation risk in Gunnison's prairie dogs (Cynomys gunnisoni)

2002 ◽  
Vol 80 (7) ◽  
pp. 1197-1203 ◽  
Author(s):  
J L Verdolin ◽  
C N Slobodchikoff
Keyword(s):  
Predation Risk ◽  
Colony Size ◽  
Perceived Risk ◽  
Group Living ◽  
Prairie Dogs ◽  
Foraging Efficiency ◽  
Individual Risk ◽  
Behavioral Strategies ◽  
Cynomys Gunnisoni ◽  
Gunnison's Prairie Dogs

Group living in animals is believed to confer advantages related to a decrease in predation risk and an energetic trade-off between vigilance and foraging efficiency. Eight Gunnison's prairie dog, Cynomys gunnisoni, colonies in Flagstaff, Arizona (elevation 2300 m), were studied from April to August 2000 to examine the adaptive significance of colonial living in the context of predation risk and antipredator behavioral strategies. Each colony was sampled once every 10 days for a period of 3 h. Upright and quadrepedal vigilance was recorded using scan samples. All predation events were recorded. Results suggest that vigilant behavior in Gunnison's prairie dogs is an antipredator strategy because the animals oriented more frequently towards the periphery of the colony while vigilant. Gunnison's prairie dogs engaged in posting, an upright bipedal posture, more frequently than scanning, a quadrepedal posture. Furthermore, there was no relationship between either form of vigilance and population size. The proportion of animals vigilant decreased significantly only on the two smallest colonies as colony size increased. On larger colonies there was no relationship between the proportion of animals vigilant and colony size. The lack of change in the proportion of animals vigilant in larger populations may be a function of perceived risk rather than actual individual risk.

scholarly journals Rain reverses diel activity rhythms in an estuarine teleost

2013 ◽  
Vol 280 (1750) ◽  
pp. 20122363 ◽  
Author(s):  
Nicholas L. Payne ◽  
Dylan E. van der Meulen ◽  
Ruan Gannon ◽  
Jayson M. Semmens ◽  
Iain M. Suthers ◽  
...  
Keyword(s):  
Predation Risk ◽  
Environmental Variability ◽  
Activity Rhythm ◽  
Adaptive Significance ◽  
Diel Activity ◽  
Foraging Efficiency ◽  
Aquatic Animal ◽  
Diurnal Activity ◽  
Activity Rhythms ◽  
Trade Offs

Activity rhythms are ubiquitous in nature, and generally synchronized with the day–night cycle. Several taxa have been shown to switch between nocturnal and diurnal activity in response to environmental variability, and these relatively uncommon switches provide a basis for greater understanding of the mechanisms and adaptive significance of circadian (approx. 24 h) rhythms. Plasticity of activity rhythms has been identified in association with a variety of factors, from changes in predation pressure to an altered nutritional or social status. Here, we report a switch in activity rhythm that is associated with rainfall. Outside periods of rain, the estuarine-associated teleost Acanthopagrus australis was most active and in shallower depths during the day, but this activity and depth pattern was reversed in the days following rain, with diurnality restored as estuarine conductivity and turbidity levels returned to pre-rain levels. Although representing the first example of a rain-induced reversal of activity rhythm in an aquatic animal of which we are aware, our results are consistent with established models on the trade-offs between predation risk and foraging efficiency.

Activity patterns of wild Bactrian camels (Camelus bactrianus) in the northern piedmont of the Altun Mountains, China

2015 ◽  
Vol 65 (3-4) ◽  
pp. 209-217 ◽  
Author(s):  
Yadong Xue ◽  
Diqiang Li ◽  
Wenfa Xiao ◽  
Fang Liu ◽  
Yuguang Zhang ◽  
...  
Keyword(s):  
Seasonal Variation ◽  
Endangered Species ◽  
Activity Patterns ◽  
Relative Activity ◽  
Diel Activity ◽  
Arid Areas ◽  
Critically Endangered Species ◽  
Camelus Bactrianus ◽  
Diel Activity Patterns ◽  
Bactrian Camels

There are significant gaps in our knowledge of wild camel ecology; especially the activity patterns that allow them to adapt to desert environments. The wild Bactrian camel (Camelus bactrianus) is a critically endangered species that survives in the extreme desert conditions of Central Asia. We conducted camera trapping surveys at seven watering sites in the northern piedmont of the Altun Mountains from 2010 to 2012. We analyzed the frequency of photo-captures to elucidate the wild camels’ diel activity patterns, and the seasonal variation in their activity at watering sites. We found that these wild camels were predominantly diurnal at watering sites, with an increase in relative activity from sunrise, reaching a peak toward midday, and then gradually decreasing in activity until sunset. The camels visited watering sites more often in winter than in summer. These results provide a guide for water development in the conservation of ungulates in arid areas.

scholarly journals Effects of human settlement and roads on diel activity patterns of elephants (Loxodonta africana )

2018 ◽  
Vol 56 (4) ◽  
pp. 872-881 ◽  
Author(s):  
Kaitlyn M. Gaynor ◽  
Paola S. Branco ◽  
Ryan A. Long ◽  
Dominique D. Gonçalves ◽  
Petter K. Granli ◽  
...  
Keyword(s):  
Activity Patterns ◽  
Loxodonta Africana ◽  
Diel Activity ◽  
Human Settlement ◽  
Diel Activity Patterns

scholarly journals Activity patterns of the small and medium felid (Mammalia: Carnivora: Felidae) guild in northeastern India

2019 ◽  
Vol 11 (4) ◽  
pp. 13432-13447 ◽  
Author(s):  
Shomita Mukherjee ◽  
Priya Singh ◽  
André Pinto Silva ◽  
Chandan Ri ◽  
Kashmira Kakati ◽  
...  
Keyword(s):  
Activity Patterns ◽  
Regional Scale ◽  
Diel Activity ◽  
Point Scale ◽  
Clouded Leopard ◽  
Northeastern India ◽  
Additional Information ◽  
Extant Species ◽  
Diel Activity Patterns ◽  
Leopard Cat

Fifteen extant species of cats inhabit India, and the northeastern region of the country is among the richest with nine species.  Among these are the “standard four”, an assemblage of Clouded Leopard Neofelis nebulosa, Asiatic Golden Cat Catopuma temminckii, Marbled Cat Pardofelis marmorata, and Leopard Cat Prionailurus bengalensis, which also occur across southeastern Asia.  Within India, despite several surveys in this region, very little information exists on the ecology of this assemblage to explain their co-occurrence.  In this paper, we put together data from several independent camera trapping studies over 10 sites across northeastern India to examine and interpret diel activity patterns of this group.  While we present results for all the four species, we focus on two species, the Marbled Cat and Leopard Cat, which are of very similar body size and are potential competitors.  We used kernel density estimates to measure diel activity patterns of all four species and overlap in activity between Marbled Cat and Leopard Cat at the regional scale as well as the point scale.  We obtained 783 captures of the standard four from >27,500 trap nights.  The Asiatic Golden Cat and Marbled Cat were strongly diurnal, Clouded Leopard largely crepuscular and nocturnal, and Leopard Cat largely nocturnal.  The degree of overlap between Marbled Cat and Leopard Cat activity was low and in consensus with other studies across southeastern Asia.  We interpret this as the differing niche spaces of the two cats due to their specific pre-existing adaptations, not restricted to the effects of competition.  The point scale analysis when both cats are captured at the same location and separately show no shift in activity pattern, supporting our hypothesis of pre-existing differences in resources, such as food, playing a major role in facilitating co-existence.  Our study, however, is preliminary and additional information with robust analysis is required to test this finding.

scholarly journals Non-uniform evolutionary response of gecko eye size to changes in diel activity patterns

2018 ◽  
Vol 14 (5) ◽  
pp. 20180064 ◽  
Author(s):  
Lars Schmitz ◽  
Timothy E. Higham
Keyword(s):  
Phenotypic Diversity ◽  
Activity Patterns ◽  
Model Fitting ◽  
Regime Shifts ◽  
Least Square ◽  
Diel Activity ◽  
Relevant Variable ◽  
Eye Size ◽  
Evolutionary Response ◽  
Diel Activity Patterns

Geckos feature a large range of eye sizes, but what drives this phenotypic diversity is currently unknown. Earlier studies point towards diel activity patterns (DAPs) and locomotory mode, but phylogenetic comparative studies in support of the proposed adaptive mode of eye evolution are lacking. Here, we test the hypothesis of DAPs as the driver of eye size evolution with a dataset on 99 species of gecko. Results from phylogenetic generalized least-square analysis (PGLS) and multivariate model-fitting reveal smaller eyes in diurnal geckos consistent with different phenotypic optima. However, Bayesian analyses of selective regime shifts demonstrate that only two of nine transitions from nocturnal to diurnal activity are coupled with decreases in eye size, and two other regime shifts are not associated with DAP transitions. This non-uniform evolutionary response suggests that eye size is not the only functionally relevant variable. Evolutionary adaptations may therefore include different combinations of several traits (e.g. photoreceptors), all with the same functional outcome. Our results further demonstrate that DAP only partially explains eye size diversity in geckos. As open habitats favour the evolution of large eyes while obstructed habitats favour small eyes, the degree of habitat clutter emerges as another potential axis of eye diversification.

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