Individual variation in vigilance in female eastern grey kangaroos

Dannock, R.J.; Blomberg, Simon P.; Goldizen, Anne W.

doi:10.1071/zo12122

Cited by 10 publications

(7 citation statements)

References 49 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Type C, in which vigilance decreases more rapidly with group size for individuals facing high risk, was not expected and indeed was only found in a few cases. In one such case, female eastern grey kangaroos ( Macropus giganteus ) decreased their vigilance in larger groups more rapidly when facing threats from males (Dannock, Blomberg, & Goldizen, ), suggesting that males might be more threatening when females are in small groups. Unexpected results such as this should spur the development of social vigilance models.…”

Section: Discussionmentioning

confidence: 99%

On how risk and group size interact to influence vigilance

Beauchamp¹

2019

Biological Reviews

View full text Add to dashboard Cite

Vigilance allows animals to monitor their surroundings for signs of danger associated with predators or rivals. As vigilance is costly, models predict that it should increase when the risk posed by predators or rivals increases. In addition, vigilance is expected to decrease in larger groups that provide more safety against predators. Risk and group size are thus two key determinants of vigilance. Together, they could have additive or interactive effects. If risk and group size interacted, the magnitude of the group-size effect on vigilance would vary depending on the level of risk experienced, implying that the benefits of sociality in terms of vigilance vary with risk. Depending on the model, vigilance is predicted to decrease more rapidly with group size at low risk or at high risk. Little work has focused directly on the interaction between risk and group size, making it difficult to understand under which conditions particular interactive effects arise and whether interactive effects are common in natural systems. I review the vast literature on vigilance in birds and mammals to assess whether interactive effects between risk and group size are common, and if present, which pattern occurs more frequently. In studies involving predation risk, the greatest proportion reported no statistically significant interactive effects. In other cases, vigilance decreased with group size more rapidly at low or high risk in a similar proportion of studies. In studies involving risk posed by rivals (social risk), most documented a more rapid decrease in vigilance with group size at low than at high risk, as predicted if the need to monitor rivals increases in larger groups. Low statistical power to detect interactive effects might have been an issue in several studies. The absence of interactive effects, on the other hand, might suggest constraints or limits on the ability of animals to adjust vigilance to current risk or group sizes. Interactive effects on vigilance have implications for the evolution of sociality and for our understanding of the phenotypic plasticity of predator-and competitor-induced defences and deserve more attention in future studies.

show abstract

Section: Discussionmentioning

confidence: 99%

On how risk and group size interact to influence vigilance

Beauchamp¹

2019

Biological Reviews

View full text Add to dashboard Cite

show abstract

“…Associations between females have been shown to be non-random , with some females having preferred associates (Best, Dwyer, Seddon, & Goldizen, 2014;Carter, MacDonald, Thomson, & Goldizen, 2009), showing that females differ in their patterns of sociability. In addition, between-individual variation in vigilance has been previously described (Carter, Pays, et al 2009;Dannock, Blomberg, & Goldizen, 2013) and related to boldness in eastern grey kangaroos, tending to support the behavioural hypothesis . Ecological drivers and individuals' characteristics such as group size, patch attractiveness and reproductive states have also been reported to shape feeding rates and/or vigilance in this species (e.g.…”

Section: Introductionsupporting

confidence: 53%

“…My MSc research showed that the absence of variation in total vigilance with group size in some studies of this species could be explained by the combination of a decrease in anti-predator vigilance and an increase in social vigilance as group size increases . Recent studies showed the existence of significant differences among individuals in eastern grey kangaroos' mean vigilance levels and in their adjustment of vigilance as group size increased (Carter et al 2009a, Dannock et al 2013. In their study, Carter et al (2009a) revealed that, among the same population, different females decreased, increased or did not exhibit any variation in their vigilance levels as group size increased.…”

Section: -2-1 Eastern Grey Kangaroosmentioning

confidence: 98%

How do herbivorous mammals adjust their trade-off between food and safety?

Favreau¹

View full text Add to dashboard Cite

Prey species foraging under a risk of predation have to trade between food acquisition and safety from predation in order to increase their fitness. This trade-off is commonly investigated by studying the trade-off between foraging and vigilance activities. However, vigilance and foraging can be affected by numerous environmental, social, and individual parameters which can also vary seasonally and differ between individuals from the same population. In this context, the overall objective of my PhD was to better understand how herbivorous prey animals manage the feeding/vigilance trade-off at a fine scale, considering the wide range of variables that may affect it, individual variation, and the different functions of vigilance, using female eastern grey kangaroos (Macropus giganteus) and impalas (Aepyceros melampus) as models.

show abstract

“…Recent studies have shown individual variation in vigilance behavior (Boujja‐Miljour et al., 2018; Dannock et al., 2013; Favreau et al., 2014; Rieucau et al., 2010). However, few studies have looked at the relationship between predator density, vigilance, and individual variation in vigilance behavior.…”

Section: Discussionmentioning

confidence: 99%

Heads up! Variation in the vigilance of foraging chipmunks in response to experimental manipulation of perceived risk

McWaters

Pangle

2021

Ethology

View full text Add to dashboard Cite

Vigilance is a behavior in which an organism is gaining information about its environment, often used for predator detection. Vigilance is influenced by the risk that an organism perceives. Animals may vary their use of vigilance behaviors by modifying not only the percent time they dedicate to vigilance, but also the duration of vigilance bouts, rate of vigilance bouts, and type of vigilance posture. Assuming these different vigilance tactics come at different costs to the individual, different sources of perceived risk should elicit specific vigilance strategies. Here, we experimentally altered the sight lines of foraging Eastern chipmunks (Tamias striatus). We carried out our field work in three locations in Michigan that vary from low (an island site) to high predator pressure. Our results show that chipmunks respond to changes in their immediate microhabitat by altering the rate of vigilance, regardless of predator density. On the other hand, chipmunks at sites with lower predator densities spend less time vigilant when compared to sites with higher predator densities and they utilize vigilance postures that decrease vigilance but do not completely halt feeding. Further research should aim to quantify costs and benefits of vigilance postures and strategies to further our understanding of how individuals balance the trade‐off between mortality and energy gain.

show abstract

Individual variation in vigilance in female eastern grey kangaroos

Cited by 10 publications

References 49 publications

On how risk and group size interact to influence vigilance

On how risk and group size interact to influence vigilance

How do herbivorous mammals adjust their trade-off between food and safety?

Heads up! Variation in the vigilance of foraging chipmunks in response to experimental manipulation of perceived risk

Contact Info

Product

Resources

About