Anti-predator behaviour of Sahamalaza sportive lemurs, Lepilemur sahamalazensis, at diurnal sleeping sites

In response to predation pressure by raptors, snakes, and carnivores, primates employ anti-predator behaviours such as avoiding areas of high predation risk, cryptic behaviour and camouflage, vigilance and group formation (including mixedspecies associations), and eavesdropping on other species’ alarm calls. After detecting a predator, primates can produce alarm calls, show predator-specific escape strategies or even mob the predator. It remains unclear how solitary nocturnal primates respond to diurnal predation pressure while they sleep or rest. The aim of this study was to investigate the diurnal anti-predator behaviour of the nocturnal and solitary Sahamalaza sportive lemur, Lepilemur sahamalazensis, which regularly rests in exposed locations. We observed the responses of 32 Sahamalaza sportive lemurs to playbacks of territorial calls of an aerial predator (Madagascar harrier hawk), mating calls of a terrestrial predator (fossa), and the contact calls of a medium-sized bird (crested coua) as a control, at different diurnal sleeping sites. Lemurs never showed a flight response after replays of predator or control calls, but regularly froze after harrier hawk calls. Lemurs scanned the sky immediately after playback of harrier hawk calls, and the ground or trees after fossa calls. Lemur vigilance increased significantly after both predator calls. After crested coua calls the animals became significantly less vigilant, suggesting that contact calls of this bird serve as indicators of predator absence. We found no response differences between different types of sleeping sites. Our results show that resting Sahamalaza sportive lemurs recognise predator vocalisations as indicators of increased predation risk, discern vocalizations of different predators, and employ anti-predator behaviours specific for different predator classes. Their behavioural responses while resting or sleeping are comparable to those of active primates, and their response rate of 80% shows that this solitary and nocturnal primate is constantly aware of its environment.

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Habitat as a source of intrapopulational variation of ornament size in Galápagos lava lizards (Microlophus albemarlensis complex)

Amphibia-Reptilia ◽

10.1163/156853808784125081 ◽

2008 ◽

Vol 29 (2) ◽

pp. 278-283 ◽

Cited By ~ 3

Author(s):

Mark Jordan ◽

Howard Snell ◽

Jennifer Hollis ◽

Paul Stone

Keyword(s):

Predation Risk ◽

Body Mass ◽

Predator Avoidance ◽

Habitat Structure ◽

Predation Pressure ◽

Residual Body ◽

Galápagos Islands ◽

Vegetative Cover ◽

High Predation ◽

Intrapopulational Variation

Abstract Gradients in habitat structure are expected to influence the outcome of selection on traits that contribute to communicative display. Galápagos lava lizards (Microlophus albemarlensis complex) on Isla Plaza Sur in the Galápagos Islands occur across a gradient of vegetative cover. Previous work in this population has shown that traits associated with predator avoidance are magnified in habitats with low vegetative cover. This pattern suggests that predation pressure differs by habitat and thus, may act to select against the elaboration of ornamentation. We measured the size of the chin patch, an ornament known to be used in intraspecific signaling, to test this hypothesis. The area of the chin patch was dependent on both snout-vent length and residual body mass. In contrast to expectation, males had larger chin patches in the sparsely vegetated habitat suggested to have high predation risk. This result raises questions about the presumed survival cost of ornament elaboration.

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Trophic shift and the origin of birds

10.1101/2020.08.18.256131 ◽

2020 ◽

Author(s):

Yonghua Wu

Keyword(s):

Predation Risk ◽

Digestive System ◽

Predation Pressure ◽

Flapping Flight ◽

Foraging Efficiency ◽

Fat Digestion ◽

Trophic Shift ◽

High Predation ◽

High Predation Pressure ◽

Selection Of

AbstractBirds are characterized by evolutionary specializations of both locomotion (e.g., flapping flight) and digestive system (toothless, crop, and gizzard), while the potential selection pressures responsible for these evolutionary specializations remain unclear. Here we used a recently developed molecular phyloecological method to reconstruct the diets of the ancestral archosaur and of the common ancestor of living birds (CALB). Our results showed that the ancestral archosaur exhibited a predominant Darwinian selection of protein and fat digestion and absorption, whereas the CALB showed a marked enhanced selection of carbohydrate and fat digestion and absorption, suggesting a trophic shift from carnivory to herbivory (fruit, seed, and/or nut-eater) at the archosaur-to-bird transition. The evolutionary shift of the CALB to herbivory may have essentially made them become a low-level consumer and, consequently, subject to relatively high predation risk from potential predators such as gliding maniraptorans, from which birds descended. Under the relatively high predation pressure, ancestral birds with gliding capability may have then evolved not only flapping flight as a possible anti-predator strategy against gliding predatory maniraptorans but also the specialized digestive system as an evolutionary tradeoff of maximizing foraging efficiency and minimizing predation risk. Our results suggest that the powered flight and specialized digestive system of birds may have evolved as a result of their tropic shift-associated predation pressure.

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Acoustic communication in the Red-vented Bulbul Pycnonotus cafer

Anais da Academia Brasileira de Ciências ◽

10.1590/s0001-37652004000200024 ◽

2004 ◽

Vol 76 (2) ◽

pp. 350-358 ◽

Cited By ~ 9

Author(s):

Anil Kumar

Keyword(s):

Acoustic Communication ◽

Wide Band ◽

Predation Pressure ◽

Alarm Calls ◽

Type I ◽

Structural Variations ◽

Pair Bonds ◽

Contact Calls ◽

Pycnonotus Cafer ◽

Context Specific

This paper deals with acoustic communication in the Red-vented Bulbul Pycnonotus cafer. This species emits a high variety of vocal signals that can be classified on the basis of their acoustical features and context of production. Individuals sang throughout the year and most songs were discrete and stereotyped. The songs were composed of strophes (phrases) with minor structural variations of elements that were preceded and followed by a temporal gap (3 to 12s). Most strophes were composed of 2 to 6 elements that were often dissimilar in structure and ranging from 0.98 to 4.5 kHz. The biological function of the song appeared to be to maintain pair bonds and to synchronize breeding activities. Different types of context-specific calls were identified. Individuals produced Type-I alarm calls (fast and wide-band, 1.03 to 6.36 kHz) under low predation pressure andType-II calls (narrowfrequency range, 1.37 to 3.39 kHz) under high predation pressure. Roosting calls were fast and wide-band signals phonetically similar to Type-I alarm calls. Three types of begging/contact calls were recorded in nestlings/fledglings. Greeting calls and flight calls were composed of complex phrases, like song, but were short and used for proximate functions.

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Molecular phyloecology suggests a trophic shift concurrent with the evolution of the first birds

Communications Biology ◽

10.1038/s42003-021-02067-4 ◽

2021 ◽

Vol 4 (1) ◽

Author(s):

Yonghua Wu

Keyword(s):

Predation Risk ◽

Digestive System ◽

Common Ancestor ◽

Predation Pressure ◽

Flapping Flight ◽

Foraging Efficiency ◽

Trophic Shift ◽

High Predation ◽

The Common ◽

High Predation Pressure

AbstractBirds are characterized by evolutionary specializations of both locomotion (e.g., flapping flight) and digestive system (toothless, crop, and gizzard), while the potential selection pressures responsible for these evolutionary specializations remain unclear. Here we used a recently developed molecular phyloecological method to reconstruct the diets of the ancestral archosaur and of the common ancestor of living birds (CALB). Our results suggest a trophic shift from carnivory to herbivory (fruit, seed, and/or nut eater) at the archosaur-to-bird transition. The evolutionary shift of the CALB to herbivory may have essentially made them become a low-level consumer and, consequently, subject to relatively high predation risk from potential predators such as gliding non-avian maniraptorans, from which birds descended. Under the relatively high predation pressure, ancestral birds with gliding capability may have then evolved not only flapping flight as a possible anti-predator strategy against gliding predatory non-avian maniraptorans but also the specialized digestive system as an evolutionary tradeoff of maximizing foraging efficiency and minimizing predation risk. Our results suggest that the powered flight and specialized digestive system of birds may have evolved as a result of their tropic shift-associated predation pressure.

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High predation risk for a small mammal: the eastern pygmy-possum (Cercartetus nanus)

Australian Mammalogy ◽

10.1071/am12034 ◽

2013 ◽

Vol 35 (2) ◽

pp. 149 ◽

Cited By ~ 5

Author(s):

Bradley Law ◽

Mark Chidel ◽

Alf Britton

Keyword(s):

Predation Risk ◽

Small Mammal ◽

High Predation ◽

Cercartetus Nanus

We report high rates of predation within a population of eastern pygmy-possum (Cercartetus nanus) near Sydney, observed during a study of the impacts of logging on the species. Predation by reptiles was observed on six of 61 radio-tracked pygmy-possums, while two were suspected of being taken by raptors. We further investigated predation by sooty owls (Tyto tenebricosa) by identifying remains in pellets. Pygmy-possums comprised 15% of the 126 dietary items identified. Predation occurred at both logged and unlogged sites in our study. We suggest that documented high rates of predation in our study could make the species vulnerable to altered predation regimes, such as influxes of feral predators, and highlight the need for a better understanding of any influence of logging on predator activity.

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

Biological Conservation ◽

10.1016/j.biocon.2018.02.030 ◽

2018 ◽

Vol 221 ◽

pp. 67-77 ◽

Cited By ~ 2

Author(s):

Emily A. Goldstein ◽

Melissa J. Merrick ◽

John L. Koprowski

Keyword(s):

Predation Pressure ◽

High Predation ◽

High Predation Pressure

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Being hunted high and low: do differences in nocturnal sleeping and diurnal resting sites of howler monkeys (Alouatta nigerrima and Alouatta discolor) reflect safety from attack by different types of predator?

Biological Journal of the Linnean Society ◽

10.1093/biolinnean/blaa102 ◽

2020 ◽

Vol 131 (1) ◽

pp. 203-219

Author(s):

Thays Jucá ◽

Sarah Boyle ◽

Gitana Cavalcanti ◽

Thiago Cavalcante ◽

Pavel Tomanek ◽

...

Keyword(s):

Predation Risk ◽

Animal Behaviour ◽

Forest Trees ◽

Site Location ◽

Howler Monkeys ◽

Main Trunk ◽

Resting Sites ◽

Different Types ◽

Sleeping Sites ◽

Low Do

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.

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