Beak marks on the wings of butterflies and predation pressure in the field

2014 ◽  
Vol 17 (4) ◽  
pp. 371-375 ◽  
Author(s):  
Masato Ota ◽  
Masahide Yuma ◽  
Yoshito Mitsuo ◽  
Yuki Togo
Keyword(s):  
Predation Pressure

scholarly journals Effects of predation pressure and resource use on morphological divergence in omnivorous prey fish

2013 ◽  
Vol 13 (1) ◽  
pp. 132 ◽  
Author(s):  
Kristin Scharnweber ◽  
Kozo Watanabe ◽  
Jari Syväranta ◽  
Thomas Wanke ◽  
Michael T Monaghan ◽  
...  
Keyword(s):  
Resource Use ◽  
Predation Pressure ◽  
Morphological Divergence ◽  
Prey Fish

Arm regeneration in Mississippian crinoids: evidence of intense predation pressure in the Paleozoic?

Paleobiology ◽  
2005 ◽  
Vol 31 (1) ◽  
pp. 151-164 ◽  
Author(s):  
Forest J. Gahn ◽  
Tomasz K. Baumiller
Keyword(s):  
Predation Pressure

Postautotomy tail movement differs between colour morphs of the red-backed salamander (Plethodon cinereus)

2017 ◽  
Vol 38 (3) ◽  
pp. 395-399 ◽  
Author(s):  
Banan W. Otaibi ◽  
Quincey K. Johnson ◽  
Bradley J. Cosentino
Keyword(s):  
Natural Selection ◽  
Genetic Correlation ◽  
Behavioural Response ◽  
Plethodon Cinereus ◽  
Predation Pressure ◽  
Tail Autotomy ◽  
Tail Movement ◽  
Colour Morphs ◽  
Defensive Mechanism

Striped and unstriped colour morphs of the eastern red-backed salamander,Plethodon cinereus, vary in their pre-attack behavioural response to predators, but it is unknown whether the morphs vary in post-attack strategies. Both morphs employ tail autotomy, a post-attack defensive mechanism enabling an individual to release a portion of their tail to facilitate escape from predation. Postautotomy tail movement diverts attention of a predator away from the individual’s body, so natural selection should favor vigorous tail movement in both colour morphs ofP. cinereus. We compared the degree of postautotomy tail movement between morphs following simulated predation. Striped individuals exhibited substantially longer and faster tail movement than unstriped individuals. Divergence in postautotomy tail movement may be a direct evolved response to variable predation pressure between colour morphs. Alternatively, tail movement may be constrained in the unstriped morph due to a genetic correlation with colouration (e.g., pleiotropy).

Vigilance and foraging patterns of American elk during the rut in habitats with and without predators

2003 ◽  
Vol 81 (2) ◽  
pp. 266-271 ◽  
Author(s):  
Jerry O Wolff ◽  
Toni Van Horn
Keyword(s):  
Cervus Elaphus ◽  
National Park ◽  
Forest Cover ◽  
Hot Springs ◽  
Rocky Mountain ◽  
Predation Pressure ◽  
Risk Avoidance ◽  
Foraging Patterns ◽  
Survival And Reproduction ◽  
Free Environment

Animal behavior is often optimized as a trade-off between survival and reproduction. During the breeding season, mammals tend to maximize their reproductive effort within the constraints of predation pressure. When predation pressure is reduced, greater effort can be allocated to reproductive behavior and less to vigilance and predator avoidance. The objective of this study was to test the hypothesis that elk, Cervus elaphus, in Yellowstone National Park (YNP), with predators, would spend more time in vigilance and risk-avoidance behavior than would elk in Rocky Mountain National Park (RMNP), a predator-free environment. We further predicted that elk at Mammoth Hot Springs (MAM) in YNP would behave similarly to those at RMNP because predators were absent in that area of the park. Cow elk in YNP spent more time in vigilance and less in foraging during activity periods than did cows in RMNP or MAM. Also, elk in YNP retreated to forest cover during the midday inactive period, whereas elk in RMNP and MAM remained in open habitat. Vigilance was not correlated with group size at either site. Cows with calves spent more time in vigilance and less in foraging than did cows without calves in RMNP and YNP. Bull elk spent most of their time in courtship at all sites, but foraged more at RMNP than in YNP or MAM. Mean harem sizes were similar among the three sites: 17.0 in RMNP, 15.7 in YNP, and 19.0 in MAM. The proportion of cows with calves was significantly lower in the area with predators, YNP (0.10), than in the predator-free areas (0.24 in RMNP and 0.37 in MAM), probably because of greater calf mortality in YNP. Elk in YNP behaved in accordance with a predation risk, whereas those in RMNP and MAM showed less vigilance behavior.

scholarly journals Social transmission in the wild can reduce predation pressure on novel prey signals

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Liisa Hämäläinen ◽  
William Hoppitt ◽  
Hannah M. Rowland ◽  
Johanna Mappes ◽  
Anthony J. Fulford ◽  
...  
Keyword(s):  
Evolutionary Dynamics ◽  
Parus Major ◽  
Predation Pressure ◽  
Social Transmission ◽  
Blue Tit ◽  
Cyanistes Caeruleus ◽  
Novel Approach ◽  
Transmission Of Information ◽  
In The Wild ◽  
Animal Communities

AbstractSocial transmission of information is taxonomically widespread and could have profound effects on the ecological and evolutionary dynamics of animal communities. Demonstrating this in the wild, however, has been challenging. Here we show by field experiment that social transmission among predators can shape how selection acts on prey defences. Using artificial prey and a novel approach in statistical analyses of social networks, we find that blue tit (Cyanistes caeruleus) and great tit (Parus major) predators learn about prey defences by watching others. This shifts population preferences rapidly to match changes in prey profitability, and reduces predation pressure from naïve predators. Our results may help resolve how costly prey defences are maintained despite influxes of naïve juvenile predators, and suggest that accounting for social transmission is essential if we are to understand coevolutionary processes.

Low survival, high predation pressure present conservation challenges for an endangered endemic forest mammal

2018 ◽  
Vol 221 ◽  
pp. 67-77 ◽  
Author(s):  
Emily A. Goldstein ◽  
Melissa J. Merrick ◽  
John L. Koprowski
Keyword(s):  
Predation Pressure ◽  
High Predation ◽  
High Predation Pressure

Prey Aggregation Is Correlated with Increased Predation Pressure in Lake Fish Communities

1993 ◽  
Vol 50 (1) ◽  
pp. 66-73 ◽  
Author(s):  
Mark R. S. Johannes
Keyword(s):  
Population Level ◽  
Time Of Day ◽  
Predation Pressure ◽  
Predator Density ◽  
Prey Fish ◽  
Treatment Combination ◽  
Golden Shiner ◽  
Fish Aggregation ◽  
Lake Fish Communities ◽  
Lake Fish

Aggregations of prey fish, golden shiner (Notemigonus crysoleucas), were examined during 7 yr of predator manipulations in two lakes to determine whether they responded to changes in predation pressure and varied with time-of-day, age, and habitat. Regression analysis was used to examine aggregation in 12 replicate prey densities from two time periods, two ages, two habitats, three sample series, and seven predator densities. Aggregation was assessed as the variance of mean densities for each treatment combination. Multiple regression and ANCOVA analyses indicated that (1) golden shiner aggregated more during day than night, (2) their aggregation was positively related to predator density, (3) young shiner aggregated more than older ones at low predator densities, and (4) aggregation in older shiner was more responsive to increased predator densities than aggregation in younger shiner. These results provide empirical evidence that golden shiner aggregation patterns respond to predation pressure and the response varies with time and age. These results also suggest that variance in net catches can provide an index of fish aggregation and that aggregation observed at the population level is not solely dependent on species and density, but is a behavioural response mediated by several factors including predators.

The yellow-legged gull as a predator of lizards in Balearic Islands

2014 ◽  
Vol 35 (2) ◽  
pp. 207-213 ◽  
Author(s):  
Valentín Pérez-Mellado ◽  
Mario Garrido ◽  
Zaida Ortega ◽  
Ana Pérez-Cembranos ◽  
Abraham Mencía
Keyword(s):  
Balearic Islands ◽  
Predation Pressure ◽  
Vertebrate Species ◽  
Sources Of Information ◽  
Mediterranean Islands ◽  
Lizard Species ◽  
Podarcis Lilfordi ◽  
Larus Michahellis ◽  
Plasticine Models ◽  
Different Sources

Lizards and gulls cohabit in several Mediterranean islands. The yellow-legged gull, Larus michahellis, was found to prey several vertebrate species. However, precise information about the interaction between gulls and other vertebrates, particularly with lizards is still scarce. The Balearic lizard, Podarcis lilfordi, shares several coastal islets with the yellow-legged gull. Using two different sources of information, we studied the interaction of both species in Colom Island (Menorca, Balearic Islands, Spain). We studied the diet of the yellow-legged gull and learnt that the Balearic lizard is not a common prey of the yellow-legged gull. On the other hand, we studied the potential predation pressure of gulls on lizards, using plasticine models of lizards. We did two different experiments from which we can conclude that yellow-legged gulls rarely attack lizards and, consequently, cannot be considered a major threat for this endemic lizard species, at least in the population under study. Finally, we obtained evidence that plasticine models can only be employed with caution to assess predation pressure of opportunistic scavengers, much as gulls are. The majority of marks on models were not the consequence of true attacks by gulls, but the result of ground exploratory behaviour of gulls in search of any edible matter. Therefore, contrary to popular belief, in the case of the yellow-legged gull, the proportion of marked models would be an indication of ground-based wandering activity, rather than a result of its predation pressure on lizards.

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