Bad news for bobtails: understanding predatory behaviour of a resource-subsidised corvid towards an island endemic reptile

2018 ◽  
Vol 45 (7) ◽  
pp. 595
Author(s):  
W. Oversby ◽  
S. M. Ferguson ◽  
R. A. Davis ◽  
P. W. Bateman
Keyword(s):  
Human Activity ◽  
Large Population ◽  
Camera Traps ◽  
Bad News ◽  
Human Settlement ◽  
Tourism Impacts ◽  
Predatory Behaviour ◽  
Predator Prey ◽  
Island Endemic ◽  
Predation Rates

Context Resource subsidisation as a result of urbanisation and other human activity can have positive impacts for some opportunistic predators. Many species of corvid have benefitted from the expansion of human-dominated habitats; however, their impacts on co-occurring prey fauna are generally poorly understood. Aims We aimed to test the hypothesis that urbanisation associated with tourism impacts the predator–prey relationship between Australian ravens, or wardongs (Corvus coronoides), a ubiquitous corvid of southern Australia, and Rottnest Island bobtails (Tiliqua rugosa konowi), a subspecies of bobtail lizard isolated to a small (19km2) island off the coast of Western Australia. Methods Using clay model lizards and camera traps, we assessed the wardongs’ attack rates by distance from the settlement and by whether the model was in closed or open habitat. Key Results We found that while wardongs preyed upon Rottnest Island bobtails, predation was not affected by proximity to human settlement despite the highest number of wardongs being found there. Models in closed vegetation were attacked by wardong significantly more than were those in open vegetation. Implications Increased predation rates in closed vegetation suggests that current revegetation efforts on the island may be increasing the availability of preferred hunting habitat for the wardong. This finding may influence decisions by management on whether to control the large population of wardongs on the island.

Zooming in on mechanistic predator–prey ecology: Integrating camera traps with experimental methods to reveal the drivers of ecological interactions

2020 ◽  
Vol 89 (9) ◽  
pp. 1997-2012 ◽  
Author(s):  
Justine A. Smith ◽  
Justin P. Suraci ◽  
Jennifer S. Hunter ◽  
Kaitlyn M. Gaynor ◽  
Carson B. Keller ◽  
...  
Keyword(s):  
Experimental Methods ◽  
Camera Traps ◽  
Ecological Interactions ◽  
Predator Prey

Vervet monkey (Chlorocebus pygerythrus) alarm calls to leopards (Panthera pardus) function as a predator deterrent

Behaviour ◽  
2016 ◽  
Vol 153 (5) ◽  
pp. 591-606 ◽  
Author(s):  
Lynne A. Isbell ◽  
Laura R. Bidner
Keyword(s):  
Alarm Call ◽  
Vervet Monkey ◽  
Camera Traps ◽  
Alarm Calls ◽  
Gps Data ◽  
Vervet Monkeys ◽  
Panthera Pardus ◽  
Predator Prey ◽  
Gps Collars ◽  
Chlorocebus Pygerythrus

Behavioural predator–prey interactions are difficult to study, especially when predators avoid humans. To gain greater understanding of their dynamism, we conducted a 14-month field study in which we minimized human presence by employing acoustic recorders and camera traps, along with GPS collars deployed on vervet monkeys (Chlorocebus pygerythrus) and leopards (Panthera pardus) in Laikipia, Kenya. Recordings at the vervets’ sleeping site revealed that they gave ‘leopard’ alarm calls most frequently near dusk and dawn, whereas photographs showed that leopards approached vervets more closely at night, when the monkeys alarm-called less often. GPS data showed that after vervets alarm-called, leopards within 200 m quickly moved away, changing direction, but when vervets did not alarm-call, leopards continued moving forward. These results reveal that vervets’ leopard alarm calls function as a predator deterrent in addition to a conspecific warning call.

scholarly journals Wariness of coyotes to camera traps relative to social status and territory boundaries

2003 ◽  
Vol 81 (12) ◽  
pp. 2015-2025 ◽  
Author(s):  
Eveline S Séquin ◽  
Michael M Jaeger ◽  
Peter F Brussard ◽  
Reginald H Barrett
Keyword(s):  
Social Status ◽  
Human Activity ◽  
Canis Latrans ◽  
Primary Objective ◽  
Vantage Point ◽  
Camera Traps ◽  
Approach Response ◽  
Human Presence ◽  
Camera Systems ◽  
Set Up

The primary objective of this study was to develop a better understanding of coyote (Canis latrans) wariness particularly as it related to social status. We determined that territory status (controlling alpha, resident beta, or nonterritorial transient) affected vulnerability to photo-capture by infrared-triggered camera systems. All coyotes were wary of cameras, leading to relatively low numbers of photo-captures, most of which occurred at night. Alphas were significantly underrepresented in photographs and were never photo-captured inside their own territories. Betas were photographed inside and outside their territories, whereas transients were most often photographed on edges of territories. Both alphas and betas were photographed more often on territorial edges when outside their territories. We next addressed the question of how alphas were better able to avoid photo-capture. Alphas tracked human activity within their territories and presumably learned the locations of cameras as they were being set up. They did this either by approaching our location directly or by moving to a vantage point from where they could observe us. Betas and transients either withdrew or did not respond to human activity. Trials in which a dog was present were more likely to elicit an approach response from alphas. Avoidance of camera stations and the tracking of human activity implied wariness toward objects or locations resulting from their learned association with human presence rather than neophobia toward the objects themselves.

Differences in activity patterns of the Neotropical otter Lontra longicaudis between rivers of two Brazilian ecoregions

2016 ◽  
Vol 32 (2) ◽  
pp. 170-174 ◽  
Author(s):  
Marcelo Lopes Rheingantz ◽  
Caroline Leuchtenberger ◽  
Carlos André Zucco ◽  
Fernando A.S. Fernandez
Keyword(s):  
Atlantic Forest ◽  
Human Activity ◽  
Activity Patterns ◽  
Kernel Density ◽  
Camera Trap ◽  
Camera Traps ◽  
Use Of Time ◽  
Activity Behaviour ◽  
Lontra Longicaudis

Abstract:Circadian use of time is an important, but often neglected, part of an animal's niche. We compared the activity patterns of the Neotropical otter Lontra longicaudis in two different areas in Brazil using camera traps placed at the entrance of holts. We obtained 58 independent photos in the Atlantic Forest (273 camera trap-days) and 46 photos in Pantanal (300 camera trap-days). We observed different kernel density probabilities on these two areas (45.6% and 14.1% overlap between the 95% and 50% density isopleths respectively). We observed the plasticity in Neotropical otter activity behaviour with different activity patterns in the two areas. In the Pantanal, the Neotropical otter selected daylight (Ivlev = 0.23) and avoided night (Ivlev = −0.44), while in the Atlantic Forest it selected dawn (Ivlev = 0.24) and night (Ivlev = 0.14), avoiding daylight (Ivlev = −0.33). We believe that this pattern can be due to human activity or shifts in prey activity.

scholarly journals Association between shell morphology of micro-land snails (genus Plectostoma) and their predator’s predatory behaviour

2013 ◽  
Author(s):  
Thor-Seng Liew ◽  
Menno Schilthuizen
Keyword(s):  
Land Snails ◽  
Shell Morphology ◽  
Ecological Interactions ◽  
Predatory Behaviour ◽  
Predator Prey ◽  
Resting Behaviour ◽  
Biological Form ◽  
Predation Costs ◽  
Selection Of ◽  
Thickness Shell

Predator-prey interactions are among the main ecological interactions that shape the diversity of biological form. In many cases, the evolution of the mollusc shell form is presumably driven by predation. However, the adaptive significance of several uncommon, yet striking, shell traits of land snails are still poorly known. These include the distorted coiled “tuba” and the protruded radial ribs that can be found in micro-landsnails of the genus Plectostoma. Here, we experimentally tested whether these shell traits may act as defensive adaptations against predators. First, we identified the predators, namely, Atopos slugs and Pteroptyx beetle larvae, and their predatory strategies towards Plectostoma snails. Then, we characterised and quantified the possible anti-predation behaviour and shell traits of Plectostoma snails both in terms of their properties and efficiencies in defending against the Atopos slug predatory strategies, namely, shell-apertural entry and shell-drilling. The results showed that Atopos slugs would first attack the snail by shell-apertural entry, and, should this fail, shift to the energetically more costly shell-drilling strategy. We found that the shell tuba of Plectostoma snails is an effective defensive trait against shell-apertural entry attack. None of the snail traits, such as resting behaviour, shell thickness, shell tuba shape, shell rib density and intensity can protect the snail from the slug’s shell-drilling attack. However, these traits could increase the predation costs to the slug. Further analysis on the shell traits revealed that the lack of effectiveness these anti-predation shell traits may be caused by a functional trade-off between shell traits under selection of two different predatory strategies. Lastly, we discuss our results in the framework of Red Queen predator-prey coevolution and escalation, and propose several key elements for future study.

scholarly journals Predation by invasive Platydemus manokwari flatworms: a laboratory study

2019 ◽  
Vol 54 (1) ◽  
pp. 47-60 ◽  
Author(s):  
Justin Gerlach
Keyword(s):  
Laboratory Study ◽  
Climatic Factors ◽  
Generalist Predator ◽  
Predatory Behaviour ◽  
Chemical Defences ◽  
The Pacific ◽  
The Pacific Ocean ◽  
The Tropics ◽  
Air Circulation ◽  
Predation Rates

Abstract Platydemus manokwari de Beauchamp, 1963 is an invasive flatworm found on islands in the tropics, especially in the Pacific Ocean. It has been implicated in the decline of several snail populations, including the extinction of some Partula species. Its predatory behaviour was investigated to quantify predation rates and elucidate climatic influences. This laboratory study of the invasive flatworm confirms earlier reports that P. manokwari is a generalist predator of snails. It prefers small prey and avoids species defended by copious mucus, chemical defences or a tough integument. Prey are found by following damp mucus trails up to 15 h old. Flatworm activity is limited by temperature and humidity, with peak feeding at 24–30°C and 85–95% humidity. This determines the geographical spread of the species and probably also the effectiveness of arboreal predation. Aboveground air circulation leads to drying, reducing the ability of the flatworms to locate trails and remain active high off the ground. Local climatic factors may dictate how significantly P. manokwari affects snail populations.

Indirect effects in predator-prey interaction: development and predation rates by immature Neoseiulus cucumeris increased by odour from its prey (Tyrophagus putrescentiae)

2020 ◽  
Vol 25 (7) ◽  
pp. 1247-1256
Author(s):  
Xin-yao Gu ◽  
Guang-yun Li ◽  
Zhi-qiang Zhang
Keyword(s):  
Indirect Effects ◽  
Survival Rates ◽  
Predatory Mites ◽  
Tyrophagus Putrescentiae ◽  
Neoseiulus Cucumeris ◽  
Predator Prey ◽  
Factitious Prey ◽  
Consumption Rates ◽  
Prey Interaction ◽  
Predation Rates

Predator-prey interactions have long been of great interest to ecologists. Although the direct consumptive effects have received extensive research, indirect influences of odour derived from their conspecifics and prey on predators have largely been underestimated and overlooked. In this study, the indirect effects of predator-prey interactions were determined with predatory mites Neoseiulus cucumeris and its factitious prey Tyrophagus putrescentiae. The responses of immature N. cucumeris to mixed odour with their conspecifics and prey were determined in a laboratory experiment. Our results showed that the mixed odour with their conspecifics did not demonstrate any obvious influences on the survival rates, developmental periods, predation rates and activities of the predatory mites. Intriguingly, the predators prolonged their protonymphal stage and consumed more prey eggs when exposed to mixed odour with their prey. Our results indicated that the mixed odour with their conspecifics was weak and its influence was insignificant for this species, but the prey odour showed a signifcant influence on the growth and consumption rates of immature predators, which highlighted that the indirect influences of predator-prey interactions on the predator were substantial and cannot be neglected.

scholarly journals Human Activity Helps Prey Win the Predator-Prey Space Race

PLoS ONE ◽  
2011 ◽  
Vol 6 (3) ◽  
pp. e17050 ◽  
Author(s):  
Tyler B. Muhly ◽  
Christina Semeniuk ◽  
Alessandro Massolo ◽  
Laura Hickman ◽  
Marco Musiani
Keyword(s):  
Human Activity ◽  
Predator Prey ◽  
Space Race

Predatory Feeding Behavior of Epischura lacustris (Copepoda, Calanoida) and Prey Defense

1981 ◽  
Vol 38 (3) ◽  
pp. 275-279 ◽  
Author(s):  
C. Kim Wong
Keyword(s):  
Feeding Behavior ◽  
Prey Selection ◽  
Encounter Rate ◽  
Predator Prey ◽  
Bosmina Longirostris ◽  
Size Selection ◽  
Behavioral Preference ◽  
Ceriodaphnia Reticulata ◽  
Predation Rates

The predatory feeding behavior of Epischura lacustris on Bosmina longirostris and Ceriodaphnia reticulata was investigated. Epischura rarely killed Bosmina > 0.40 mm in length, but below this threshold there was no size selection because predation rates were affected mainly by encounter rate and ingestion probability. When presented with Bosmina and Ceriodaphnia, Epischura fed at higher rates on Bosmina which were more easily captured. Epischura showed no true behavioral preference or switching, and its diet included all the prey it could detect, capture, and ingest successfully. Previous diet had no effect on prey selection. Predation rates on Bosmina were not affected by the presence of algal food.Key words: predatory copepod, predator–prey interactions, size selection, switching, prey defense

scholarly journals Do functional traits improve prediction of predation rates for a disparate group of aphid predators?

2008 ◽  
Vol 98 (6) ◽  
pp. 587-597 ◽  
Author(s):  
J.R. Bell ◽  
A. Mead ◽  
D.J. Skirvin ◽  
K.D. Sunderland ◽  
J.S. Fenlon ◽  
...  
Keyword(s):  
Functional Groups ◽  
Functional Traits ◽  
Null Model ◽  
Predation Rate ◽  
Procrustes Analysis ◽  
Predatory Behaviour ◽  
Aphid Predators ◽  
Taxonomic Approach ◽  
Predation Rates ◽  
The Way

AbstractAphid predators are a systematically disparate group of arthropods united on the basis that they consume aphids as part of their diet. In Europe, this group includes Araneae, Opiliones, Heteroptera, chrysopids, Forficulina, syrphid larvae, carabids, staphylinids, cantharids and coccinellids. This functional group has no phylogenetic meaning but was created by ecologists as a way of understanding predation, particularly for conservation biological control. We investigated whether trait-based approaches could bring some cohesion and structure to this predator group. A taxonomic hierarchy-based null model was created from taxonomic distances in which a simple multiplicative relationship described the Linnaean hierarchies (species, genera, etc.) of fifty common aphid predators. Using the same fifty species, a functional groups model was developed using ten behavioural traits (e.g. polyphagy, dispersal, activity, etc.) to describe the way in which aphids were predated in the field. The interrelationships between species were then expressed as dissimilarities within each model and separately analysed using PROXSCAL, a multidimensional scaling (MDS) program. When ordinated using PROXSCAL and then statistically compared using Procrustes analysis, we found that only 17% of information was shared between the two configurations. Polyphagy across kingdoms (i.e. predatory behaviour across animal, plant and fungi kingdoms) and the ability to withstand starvation over days, weeks and months were particularly divisive within the functional groups model. Confirmatory MDS indicated poor prediction of aphid predation rates by the configurations derived from either model. The counterintuitive conclusion was that the inclusion of functional traits, pertinent to the way in which predators fed on aphids, did not lead to a large improvement in the prediction of predation rate when compared to the standard taxonomic approach.

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