Vulnerability To Predation in Baboon Populations

Behaviour ◽  
1994 ◽  
Vol 131 (3-4) ◽  
pp. 293-304 ◽  
Author(s):  
Guy Cowlishaw

AbstractThis study investigates patterns of predation in Papio baboon populations across Africa. Using anecdotal reports collated from the primate and predator literature, the following analyses are conducted. First, the primary predators of baboons are identified. These are shown to be the terrestrial carnivores; in order of importance leopards, lions and hyena. Second, patterns of large felid predation on baboons are investigated in detail. In terms of prey selection, leopards are more likely to take (1) adults than juveniles and (2) males than females. While lion attacks are strictly diurnal, leopards will attack during both the day and night. However, both predators are usually limited to conducting attacks when and/or where visibility is limited. Leopards were about twice as successful as lions at hunting baboons. Nocturnal leopard hunts were more successful than diurnal hunts when twilight cases were excluded; in relation to this, leopard attacks at sleeping sites were more likely to end in prey capture than attacks at waterholes. Finally, patterns of baboon retaliation against predators revealed that males are more likely to retaliate than females and that such behaviour effectively deters predators. Males are particularly aggressive towards leopards, where in 4/11 cases the leopard was killed. These results may help to resolve a number of outstanding controversies regarding the nature of predation risk in baboons, indicating that diurnal predation is a substantial threat, that males are effective at deterring several predator species, particularly leopards, and that predators will successfully attack and capture males.

2001 ◽  
Vol 204 (17) ◽  
pp. 3039-3051 ◽  
Author(s):  
Peter C. Wainwright ◽  
Lara A. Ferry-Graham ◽  
Thomas B. Waltzek ◽  
Andrew M. Carroll ◽  
C. Darrin Hulsey ◽  
...  

SUMMARYWe characterized prey-capture strategies in seven species of cichlid fishes representing diverse trophic habits and anticipated feeding abilities. The species examined were Petenia splendida, Cichla ocellaris, Cichlasoma minckleyi, Astronotus ocellatus, Crenicichla geayi, Heros severus (formerly Cichlasoma severum) and Cyprichromis leptosoma. Three individuals per species were filmed with video at 500Hz as they captured live adult Artemia sp. and Poecilia reticulata. For each feeding sequence, we measured the contribution of predator movement towards the prey (i.e. ram) and the movement of prey towards the predator due to suction. The use of ram differed significantly among prey types and predator species, varying as much as sixfold across predator species. High values of ram resulted in high attack velocities. Jaw protrusion contributed as much as 50% to overall ram values in some species, verifying its role in enhancing attack velocity. Suction distance did not vary significantly among species. Diversity in prey-capture behavior was therefore found to reflect differences among species in the strategy used to approach prey. Limited variation in the distance from which prey were sucked into the mouth is interpreted as the result of an expected exponential decline in water velocity with distance from the mouth of the suction-feeding predator. We propose that this relationship represents a major constraint on the distance over which suction feeding is effective for all aquatic-feeding predators.


2020 ◽  
Vol 131 (1) ◽  
pp. 203-219
Author(s):  
Thays Jucá ◽  
Sarah Boyle ◽  
Gitana Cavalcanti ◽  
Thiago Cavalcante ◽  
Pavel Tomanek ◽  
...  

Abstract Predation risk is important in influencing animal behaviour. We investigated how the choice of nocturnal sleeping and diurnal resting sites by two species of primates was influenced by the most likely forms of attack (diurnal raptors and nocturnal felids). We recorded vertical and horizontal patterns of occupancy for 47 sleeping and 31 resting sites, as well as the presence of lianas or vines on trees. We compared the heights of trees used as resting or sleeping sites by the monkeys with those of 200 forest trees that the monkeys did not use. Trees used as nocturnal sleeping sites were taller than those used as diurnal resting sites, and taller than trees that the monkeys did not use. However, while trees used as diurnal resting sites were not significantly taller than non-used trees, diurnal resting sites were located on branches closer to the ground, closer to the main trunk of the tree and in trees with more lianas/vines than nocturnal sleeping sites. The differences in site location can be explained by the type of predator most likely to attack at a particular time: raptors in the day and felids at night.


ARCTIC ◽  
2021 ◽  
Vol 74 (1) ◽  
pp. 22-29
Author(s):  
Kevin G. Young ◽  
Lisa V. Kennedy ◽  
Paul A. Smith ◽  
Erica Nol

When monitoring the breeding ecology of birds, the causes and times of nest failure can be difficult to determine. Cameras placed near nests allow for accurate monitoring of nest fate, but their presence may increase the risk of predation by attracting predators, leading to biased results. The relative influence of cameras on nest predation risk may also depend on habitat because predator numbers or behaviour can change in response to the availability or accessibility of nests. We evaluated the impact of camera presence on the predation rate of artificial nests placed within mesic tundra habitats used by Arctic-breeding shorebirds. We deployed 94 artificial nests, half with cameras and half without, during the shorebird-nesting season of 2015 in the East Bay Migratory Bird Sanctuary, Nunavut. Artificial nests were distributed evenly across sedge meadow and supratidal habitats typically used by nesting shorebirds. We used the Cox proportional hazards model to assess differential nest survival in relation to camera presence, habitat type, placement date, and all potential interactions. Artificial nests with cameras did not experience higher predation risk than those without cameras. Predation risk of artificial nests was related to an interaction between habitat type and placement date. Nests deployed in sedge meadows and in supratidal habitats later in the season were subject to a higher risk of predation than those deployed in supratidal habitats early in the season. These differences in predation risk are likely driven by the foraging behaviour of Arctic fox (Vulpes lagopus), a species that accounted for 81% of observed predation events in this study. Arctic fox prey primarily on Arvicoline prey and goose eggs at this site and take shorebird nests opportunistically, perhaps more often later in the season when their preferred prey becomes scarcer. This study demonstrates that, at this site, cameras used for nest monitoring do not influence predation risk. Evaluating the impact of cameras on predation risk is critical prior to their use, as individual study areas may differ in terms of predator species and behaviour.


Author(s):  
Harish Prakash ◽  
Stefan Greif ◽  
Yossi Yovel ◽  
Rohini Balakrishnan

Prey signalling in aggregation become more conspicuous with increasing numbers and tend to attract more predators. Such grouping may, however, benefit prey by lowering the risk of being captured due to the predator's difficulty in targeting individuals. Previous studies have investigated anti-predatory benefits of prey aggregation using visual predators, but it is unclear whether such benefits are gained in an auditory context. We investigated whether katydids of the genus Mecopoda gain protection from their acoustically eavesdropping bat predator, Megaderma spasma, when calling in aggregation. In a choice experiment, bats approached calls of prey aggregations more often than those of prey calling alone, indicating that prey calling in aggregation are at higher risk. In prey capture tasks, however, the average time taken, and the number of flight passes made by bats before capturing a katydid, were significantly higher for prey calling in aggregation as compared to calling alone, indicating that prey face lower predation risk when calling in aggregation. Another common anti-predatory strategy, calling from within vegetation, increased the time taken by bats to capture katydids calling alone but did not increase the time taken to capture prey calling from aggregations. The increased time taken to capture a prey calling in aggregation compared to solitary calling prey offers an escape opportunity, thus providing prey signalling acoustically in aggregations with anti-predatory benefits. For bats, greater detectability of calling prey aggregations is offset by lower foraging efficiency, and this trade-off may shape predator foraging strategies in natural environments.


2008 ◽  
Vol 4 (6) ◽  
pp. 663-666 ◽  
Author(s):  
Otto Seppälä ◽  
Jukka Jokela

Trophically transmitted parasites often alter their intermediate host's phenotype, thereby predisposing hosts to increased predation. This is generally considered to be a parasite strategy evolved to enhance transmission to the next host. However, the adaptive value of host manipulation is not clear, as it may be associated with costs, such as increased susceptibility to predator species that are unsuitable next hosts for the parasites. Thus, it has been proposed that, to be adaptive, manipulation should be specific by predisposing hosts more strongly to predation by target hosts (next host in the life cycle) than to non-hosts. Here we formally evaluate this prediction, and show that manipulation does not have to be specific to be adaptive. However, when manipulation is nonspecific, it needs to effectively increase the overall predation risk of infected hosts if it is to increase the parasite transmission probability. Thus, when initial predation risk is low, even highly nonspecific manipulation strategies can be adaptive. However, when initial predation risk is high, manipulation needs to be more specific to increase parasite transmission success. Therefore, nonspecific host manipulation may evolve in nature, but the adaptive value of a certain manipulation strategy can vary among different parasite populations depending on the variation in initial predation risk.


Oecologia ◽  
2004 ◽  
Vol 139 (1) ◽  
pp. 117-122 ◽  
Author(s):  
Heather D. Vance-Chalcraft ◽  
Daniel A. Soluk ◽  
Nicholas Ozburn

Animals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 428
Author(s):  
Mᵃ Carmen Hernández ◽  
Denise M. Jara-Stapfer ◽  
Ana Muñoz ◽  
Cristian Bonacic ◽  
Isabel Barja ◽  
...  

Ecologically based rodent management strategies are arising as a sustainable approach to rodent control, allowing us to preserve biodiversity while safeguarding human economic activities. Despite predator signals being known to generally repel rodents, few field-based studies have compared the behavioral effects of several predators on different prey species, especially in Neotropical ecosystems. Here, we used camera traps to study the behavior of rodent species native to the Chilean temperate forest (Abrothrix spp., long-tailed pygmy rice rat Oligoryzomys longicaudatus) and an introduced rodent (black rat Rattus rattus). Using playbacks of raptor calls, we experimentally exposed rodents to three predation risk treatments: austral pygmy owl calls (Glaucidium nana), rufous-legged owl calls (Strix rufipes) and a control treatment (absence of owl calls). We evaluated the effects of the treatments on the time allocated to three behaviors: feeding time, locomotor activity and vigilance. Moonlight and vegetation cover were also considered in the analyses, as they can modify perceived predation risk. Results showed that predator calls and environmental factors modified prey behavior depending not only on the predator species, but also on the rodent species. Consequently, owl playbacks could be regarded as a promising rodent control tool, knowing that future studies would be critical to deeply understand differences between species in order to select the most effective predator cues.


Author(s):  
Christine A. Sundermann

Discophrya collini, a suctorian ciliate, subsists on live prey (i.e. Tetrahymena) which is captured and ingested through tentacles. The tentacles are characterized by a swelling or knob at the distal ends which contain extrusive organelles termed haptocysts that assist in prey capture and/or attachment. Prey selection is rather specific, only certain ciliated species are recognized as food. Other ciliates, flagellates, and Discophrya's own ciliated larvae for instance, can make contact with tentacles and remain unharmed. This study was undertaken to investigate and compare Discophrya's surface topography associated with the following: a) cell body, b) tentacle shaft, and c) tentacle knob. Cell surface properties have been characterized in numerous animal cell types but discovery of marked variation in different regions of a particular cell has been infrequent.


Parasitology ◽  
2008 ◽  
Vol 135 (10) ◽  
pp. 1143-1150 ◽  
Author(s):  
P. H. L. LAMBERTON ◽  
C. A. DONNELLY ◽  
J. P. WEBSTER

SUMMARYThe hypothesis that the parasiteToxoplasma gondiimanipulates the behaviour of its intermediate rat host in order to increase its chance of being predated specifically by its feline definitive host, rather than a non-definitive host predator species, was tested. The impact of a range of therapeutic drugs, previously demonstrated to be effective in preventing the development ofT. gondii-associated behavioural and cognitive alterations in rats, on definitive-host predator specificity was also tested. Using a Y-shaped maze design, we demonstrated thatT. gondii-associated behavioural changes, apparently aimed to increase predation rate, do appear to be specific to that of the feline definitive host – there were significant and consistent differences between the (untreated) infected and uninfected rats groups whereT. gondii-infected rats tended to choose the definitive host feline-predator-associated maze arm and nest-box significantly more often than a maze arm or nest-box treated with non-definitive host predator (mink) odour. Drug treatment of infected rats prevented any such host-specificity from being displayed. We discuss our results in terms of their potential implications both forT. gondiiepidemiology and the evolution of parasite-altered behaviour.


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