scholarly journals Native reptiles alter their foraging in the presence of the olfactory cues of invasive mammalian predators

2018 ◽  
Vol 5 (10) ◽  
pp. 180136 ◽  
Author(s):  
C. Webster ◽  
M. Massaro ◽  
D. R. Michael ◽  
D. Bambrick ◽  
J. L. Riley ◽  
...  
Keyword(s):  
Rapid Evolution ◽  
Recognition System ◽  
Extinction Rate ◽  
Feral Cat ◽  
Terrestrial Vertebrate ◽  
Invasive Predators ◽  
Y Maze ◽  
Grey Kangaroo ◽  
Reptile Species ◽  
Mammalian Predators

Invasive mammalian predators are linked to terrestrial vertebrate extinctions worldwide. Prey naïveté may explain the large impact invasive predators have on native prey; prey may fail to detect and react appropriately to the cues of novel predators, which results in high levels of depredation. In Australia, the feral cat ( Felis catus ) and the red fox ( Vulpes vulpes ) are implicated in more than 30 animal extinctions and the naïveté of native prey is often used to explain this high extinction rate. Reptiles are one group of animals that are heavily preyed upon by F. catus and V. vulpes . However, very few studies have examined whether reptiles are naive to their cues. In this study, we examine the ability of two native reptile species ( Morethia boulengeri and Christinus marmoratus ) to detect and distinguish between the chemical cues of two invasive predators ( V. vulpes and F. catus ) and three native predators (spotted-tailed quoll, Dasyurus maculatus; dingo, Canis lupus dingo ; eastern brown snake, Pseudonaja textilis ), as well as two non-predator controls (eastern grey kangaroo, Macropus giganteus and water). We conducted experiments to quantify the effects of predator scents on lizard foraging (the amount of food eaten) during 1 h trials within Y-maze arenas. We found both study species reduced the amount they consumed when exposed to predator scents—both native and invasive—indicating that these species are not naive to invasive predators. An evolved generalized predator-recognition system, rapid evolution or learned behaviour could each explain the lack of naïveté in some native Australian reptiles towards invasive predators.

scholarly journals Invasive predators and global biodiversity loss

2016 ◽  
Vol 113 (40) ◽  
pp. 11261-11265 ◽  
Author(s):  
Tim S. Doherty ◽  
Alistair S. Glen ◽  
Dale G. Nimmo ◽  
Euan G. Ritchie ◽  
Chris R. Dickman
Keyword(s):  
At Risk ◽  
Biodiversity Loss ◽  
Irreversible Loss ◽  
Critically Endangered Species ◽  
Invasive Predators ◽  
Evolutionary Distinctiveness ◽  
Reptile Species ◽  
Mammalian Predators ◽  
Global Biodiversity ◽  
The Impact

Invasive species threaten biodiversity globally, and invasive mammalian predators are particularly damaging, having contributed to considerable species decline and extinction. We provide a global metaanalysis of these impacts and reveal their full extent. Invasive predators are implicated in 87 bird, 45 mammal, and 10 reptile species extinctions—58% of these groups’ contemporary extinctions worldwide. These figures are likely underestimated because 23 critically endangered species that we assessed are classed as “possibly extinct.” Invasive mammalian predators endanger a further 596 species at risk of extinction, with cats, rodents, dogs, and pigs threatening the most species overall. Species most at risk from predators have high evolutionary distinctiveness and inhabit insular environments. Invasive mammalian predators are therefore important drivers of irreversible loss of phylogenetic diversity worldwide. That most impacted species are insular indicates that management of invasive predators on islands should be a global conservation priority. Understanding and mitigating the impact of invasive mammalian predators is essential for reducing the rate of global biodiversity loss.

Evolution or Extinction: Might Zooplankton Adaptively Respond to the Novel Invasive Predator Bythotrephes longimanus?

2018 ◽  
Author(s):  
Emma Bloomfield
Keyword(s):  
Vertical Migration ◽  
Diel Vertical Migration ◽  
Prey Species ◽  
Rapid Evolution ◽  
Freshwater Ecosystems ◽  
Bythotrephes Longimanus ◽  
Economic Implications ◽  
Invasive Predators ◽  
Invasive Predator ◽  
Introduced Predators

Invasive predators are a large and growing threat to species diversity and human well-being. One of the reasons invasive predators have a negative impact is that native prey species do not possess appropriate anti-predator defenses. However, rapid evolution may allow prey species to respond adaptively to introduced predators. When this occurs the impacts of invasive predators are mitigated. An invasive predator that is of concern in North America is the spiny water flea, Bythotrephes longimanus. It disrupts freshwater ecosystems through voracious consumption of zooplankton. Declines in zooplankton abundance and richness reduce water quality and recreational fishing opportunities. However, a species of zooplankton, Daphnia mendotae has been found to adaptively respond to B. longimanus. This adaptation is diel vertical migration, the behavioral change of occupying a lower position in the water column during the day to reduce predation risk. Despite the ecological and economic implications of this behavior in response to B. longimanus, it has only been studied in a few lakes. This study investigated adaptive diel vertical migration in D. mendotae from multiple lakes. This was done by measuring the vertical position of D. mendotae in artificial water columns. It was hypothesized that D. mendotae from lakes that have been invaded by B. longimanus will exhibit diel vertical migration in the presence of B. longimanus. If this hypothesis is supported, rapid evolution of diel vertical migration can be established as a widespread response. This would strengthen understanding of rapid evolution and allow lakes more vulnerable to B.longimanus to be identified.

scholarly journals Seasonal and spatial shifts in feral cat predation on native seabirds vs. non-native rats on Mikura Island, Japan

2020 ◽  
Author(s):  
Sarara Azumi ◽  
Yuya Watari ◽  
Nariko Oka ◽  
Tadashi Miyashita
Keyword(s):  
Native Species ◽  
Control Strategies ◽  
Interspecific Interactions ◽  
Rattus Rattus ◽  
Large Body ◽  
Effective Control ◽  
Alternative Prey ◽  
Feral Cat ◽  
Feral Cats ◽  
Invasive Predators

Abstract Understanding how invasive predators impact native species is essential for the development of effective control strategies, especially in insular environments where alternative non-native prey species exist. We examined seasonal and spatial shifts in diet of feral cat Felis silvestris catus focusing on the predation on native streaked shearwaters, Calonectris leucomelas, and introduced rats, Rattus rattus and R. norvegicus, which are alternative prey to shearwaters, on Mikura Island, Japan. Streaked shearwaters breed at low elevations on the island from spring to autumn, whereas rats inhabit the island throughout the year, which makes them an alternative prey when native shearwaters are absent. Fecal analysis revealed that feral cats dramatically shifted their diets from introduced rats in winter to streaked shearwaters in seabird-season in low elevation areas of the island, while cats preyed on rats throughout the year at high altitudes on the island. This finding suggests that feral cats selectively prey on shearwaters. This is probably because of their large body size and less cautious behavior, and because introduced rats sustain the cat population when shearwaters are absent. The number of streaked shearwaters killed was estimated to be 313 individuals per cat per year, which represents an indication of top-down effects of feral cats on streaked shearwaters. Further studies on the demographic parameters and interspecific interactions of the three species are required to enable effective cat management for the conservation of streaked shearwaters on this island.

Living with the enemy: a threatened prey species coexisting with feral cats on a fox-free island

2020 ◽  
Vol 47 (8) ◽  
pp. 633
Author(s):  
Vivianna Miritis ◽  
Anthony R. Rendall ◽  
Tim S. Doherty ◽  
Amy L. Coetsee ◽  
Euan G. Ritchie
Keyword(s):  
Native Species ◽  
Prey Species ◽  
Occupancy Models ◽  
Feral Cat ◽  
Terrestrial Mammals ◽  
Invasive Predators ◽  
Eastern Australia ◽  
Conservation Actions ◽  
Temporal Interactions ◽  
The Impact

Abstract ContextFeral domestic cats (Felis catus) have contributed to substantial loss of Australian wildlife, particularly small- and medium-sized terrestrial mammals. However, mitigating cat impacts remains challenging. Understanding the factors that facilitate coexistence between native prey and their alien predators could aid better pest management and conservation actions. AimsWe estimated feral cat density, examined the impact of habitat cover on long-nosed potoroos (Potorous tridactylus tridactylus), and assessed the spatial and temporal interactions between cats and potoroos in the ‘Bluegums’ area of French Island, south-eastern Australia. Materials and methodsWe operated 31 camera stations across Bluegums for 99 consecutive nights in each of winter 2018 and summer 2018/19. We used a spatially explicit capture–recapture model to estimate cat density, and two-species single-season occupancy models to assess spatial co-occurrence of cats and potoroos. We assessed the influence of vegetation cover and cat activity on potoroo activity by using a dynamic occupancy model. We also used image timestamps to describe and compare the temporal activities of the two species. Key resultsBluegums had a density of 0.77 cats per km2 across both seasons, although this is a conservative estimate because of the presence of unidentified cats. Cats and long-nosed potoroos were detected at 94% and 77% of camera stations, respectively. Long-nosed potoroo detectability was higher in denser vegetation and this pattern was stronger at sites with high cat activity. Cats and potoroos overlapped in their temporal activity, but their peak activity times differed. Conclusions Feral cat density at Bluegums, French Island, is higher than has been reported for mainland Australian sites, but generally lower than in other islands. Long-nosed potoroos were positively associated with cats, potentially indicating cats tracking potoroos as prey or other prey species that co-occur with potoroos. Temporal activity of each species differed, and potoroos sought more complex habitat, highlighting possible mechanisms potoroos may use to reduce their predation risk when co-occurring with cats. ImplicationsOur study highlighted how predator and prey spatial and temporal interactions, and habitat cover and complexity (ecological refuges), may influence the ability for native prey to coexist with invasive predators. We encourage more consideration and investigation of these factors, with the aim of facilitating more native species to persist with invasive predators or be reintroduced outside of predator-free sanctuaries, exclosures and island safe havens.

How many reptiles are killed by cats in Australia?

2018 ◽  
Vol 45 (3) ◽  
pp. 247 ◽  
Author(s):  
J. C. Z. Woinarski ◽  
B. P. Murphy ◽  
R. Palmer ◽  
S. M. Legge ◽  
C. R. Dickman ◽  
...  
Keyword(s):  
Population Size ◽  
Arid Regions ◽  
Predation Rate ◽  
Population Viability ◽  
Natural Environments ◽  
Feral Cat ◽  
Feral Cats ◽  
Reptile Species ◽  
Conservation Concern ◽  
The Impact

Context Feral cats (Felis catus) are a threat to biodiversity globally, but their impacts upon continental reptile faunas have been poorly resolved. Aims To estimate the number of reptiles killed annually in Australia by cats and to list Australian reptile species known to be killed by cats. Methods We used (1) data from >80 Australian studies of cat diet (collectively >10 000 samples), and (2) estimates of the feral cat population size, to model and map the number of reptiles killed by feral cats. Key results Feral cats in Australia’s natural environments kill 466 million reptiles yr–1 (95% CI; 271–1006 million). The tally varies substantially among years, depending on changes in the cat population driven by rainfall in inland Australia. The number of reptiles killed by cats is highest in arid regions. On average, feral cats kill 61 reptiles km–2 year–1, and an individual feral cat kills 225 reptiles year–1. The take of reptiles per cat is higher than reported for other continents. Reptiles occur at a higher incidence in cat diet than in the diet of Australia’s other main introduced predator, the European red fox (Vulpes vulpes). Based on a smaller sample size, we estimate 130 million reptiles year–1 are killed by feral cats in highly modified landscapes, and 53 million reptiles year–1 by pet cats, summing to 649 million reptiles year–1 killed by all cats. Predation by cats is reported for 258 Australian reptile species (about one-quarter of described species), including 11 threatened species. Conclusions Cat predation exerts a considerable ongoing toll on Australian reptiles. However, it remains challenging to interpret the impact of this predation in terms of population viability or conservation concern for Australian reptiles, because population size is unknown for most Australian reptile species, mortality rates due to cats will vary across reptile species and because there is likely to be marked variation among reptile species in their capability to sustain any particular predation rate. Implications This study provides a well grounded estimate of the numbers of reptiles killed by cats, but intensive studies of individual reptile species are required to contextualise the conservation consequences of such predation.

A baseline terrestrial vertebrate fauna survey of Pullen Pullen; a significant conservation reserve in south-west Queensland

2020 ◽  
Author(s):  
S.G. Kearney ◽  
P.L. Kern ◽  
A.S. Kutt
Keyword(s):  
Adaptive Management ◽  
Ground Cover ◽  
Short Paper ◽  
Important Reserve ◽  
Terrestrial Vertebrate ◽  
South West ◽  
Reptile Species ◽  
Sminthopsis Macroura ◽  
Surrounding Landscape ◽  
Grassland Habitats

Arid and desert landscapes are characterised as boom-bust systems, and sometimes its fauna can remain cryptic or hidden. This short paper reports the results of baseline monitoring of the terrestrial fauna in the Bush Heritage Pullen Pullen reserve in south-west Queensland, most notable for the presence of the night parrot Pezoporus occidentalis. We conducted two fauna surveys over 22 sites representing Spinifex grasslands, and Mitchell and Chenopod grassland habitats in 2018 and 2019, using pitfall, funnel and Elliott traps, and active searching. A total of eight mammal and 28 reptile species comprising 730 records were documented, as well as eight additional incidental species. Frequently recorded species were Ctentous lateralis, Ctenotus pantherinus, Gehyra versicolor, Tachyglossus aculeatus, Sminthopsis macroura, Pseudomys desertor. Fourteen of the species recorded were highly variable in abundance from one survey to the next. The fauna of the Spinifex grasslands, and Mitchell and Chenopod grassland sites was compositionally very different, and the extent of ground cover or Triodia in the surrounding landscape predicted the abundance of some mammals (i.e. Pseudomys desertor) and reptiles ( Delma nasuta, Ctenotus pulchellus, Cyclodomorphus melanops). These data provide a baseline for future monitoring on this important reserve, and an opportunity to enhance or increase the survey scope via additional sites and a future more adaptive management and question-driven approach.

scholarly journals Edge Artificial Intelligence: Real-Time Noninvasive Technique for Vital Signs of Myocardial Infarction Recognition Using Jetson Nano

2021 ◽  
Vol 2021 ◽  
pp. 1-19
Author(s):  
H. M. Mohan ◽  
S. Anitha ◽  
Rifai Chai ◽  
Sai Ho Ling
Keyword(s):  
Myocardial Infarction ◽  
Real Time ◽  
Performance Metrics ◽  
Color Image ◽  
Learning Algorithm ◽  
Rapid Evolution ◽  
Vital Signs ◽  
Recognition System ◽  
Single Shot ◽  
Noninvasive Technique

The history of medicine shows that myocardial infarction is one of the significant causes of death in humans. The rapid evolution in autonomous technologies, the rise of computer vision, and edge computing offers intriguing possibilities in healthcare monitoring systems. The major motivation of the work is to improve the survival rate during a cardiac arrest through an automatic emergency recognition system under ambient intelligence. We present a novel approach to chest pain and fall posture-based vital sign detection using an intelligence surveillance camera to address the emergency during myocardial infarction. A real-time embedded solution persuaded from “edge AI” is implemented using the state-of-the-art convolution neural networks: single shot detector Inception V2, single shot detector MobileNet V2, and Internet of Things embedded GPU platform NVIDIA’s Jetson Nano. The deep learning algorithm is implemented for 3000 indoor color image datasets: Nanyang Technological University Red Blue Green and Depth, NTU RGB + D dataset, and private RMS dataset. The research mainly pivots on two key factors in creating and training a CNN model to detect the vital signs and evaluate its performance metrics. We propose a model, which is cost-effective and consumes low power for onboard detection of vital signs of myocardial infarction and evaluated the metrics to achieve a mean average precision of 76.4% and an average recall of 80%.

Influence of landscape structure on invasive predators: feral cats and red foxes in the brigalow landscapes, Queensland, Australia

2012 ◽  
Vol 39 (8) ◽  
pp. 661 ◽  
Author(s):  
Cameron A. Graham ◽  
Martine Maron ◽  
Clive A. McAlpine
Keyword(s):  
Landscape Structure ◽  
Red Fox ◽  
Agricultural Landscapes ◽  
Habitat Types ◽  
Red Foxes ◽  
Detection Rates ◽  
Feral Cat ◽  
Invasive Predators ◽  
Invasive Predator ◽  
A Site

Context Invasive mammalian predators are often associated with fragmented landscapes, and can compound the impacts of habitat loss and fragmentation on native fauna. Knowledge of how invasive predators are influenced by different landscape structures can assist in the mitigation of their impacts. Aims The aim of the present study was to investigate the influence of landscape structure and site-scale habitat attributes on the frequency of feral-cat and red-fox detections in fragmented agricultural landscapes. Methods Field surveys of the frequency of red-fox and feral-cat visitation at a site scale were stratified for six different habitat types in six study subregions. The habitat types were large remnant patch interior, large remnant patch edge, small remnant patch, roadside verge, regrowth patch and open agricultural land adjacent to a remnant patch. Sites were centred in a 1-km buffer area from which landscape composition and configuration were calculated. We applied a generalised linear model and an information-theoretic approach to determine the effect size and importance and rank of the explanatory variables on red-fox, feral-cat and pooled cat and fox detection rates. Key results The most important factors influencing detection rates had a positive effect and included: the dominance of cropping in the landscape (cat, fox, pooled cat and fox); and the density of vegetation at a site scale (fox, pooled cat and fox). The number of native habitat patches was also an important factor in the models of red foxes and pooled invasive predators. Conclusion Spatially heterogeneous cropping landscapes incur higher rates of invasive-predator detections than do intact native-woodland and pasture landscapes at the 1-km scale. At a site scale, elevated invasive-predator detections occurred at sites with dense vegetation, characteristic of narrow woodland and the edges of large woodland patches. Implications The research findings highlight that vertebrate pest management needs to target highly fragmented agricultural landscapes that are more likely to have elevated levels of invasive-predator activity. Landscape restoration efforts need to consider the redesign of landscapes to make them less suitable for predators and more hospitable for native wildlife.

Small mustelids in New Zealand: invasion ecology in a different world

2018 ◽  
Author(s):  
Carolyn M. King ◽  
Grant Norbury ◽  
Andrew J. Veale
Keyword(s):  
Biological Control ◽  
New Zealand ◽  
Population Biology ◽  
Predator Prey ◽  
Invasive Predators ◽  
Mammalian Predators ◽  
Size Population ◽  
Mustela Furo ◽  
Predatory Impact ◽  
Small Mustelids

This chapter reviews the ecology of the three species of small mustelids introduced into New Zealand: the ferret (Mustela furo), the stoat (M. erminea) and the weasel (M. nivalis), for biological control of rabbits. New Zealand offers a mosaic of environments totally different from those in which the three species evolved, including a diminishing array of endemic fauna especially vulnerable to mammalian predators. Mustelids in New Zealand display significant adaptive flexibility in diet, habitat selection, co-existence, dispersal, body size, population biology and predatory impact, with results contrasting with those observable in their northern-hemisphere ancestors. These evolutionary and ecological responses by mustelids to new opportunities are of considerable interest to evolutionary ecologists, especially those interested in competition and predator-prey relationships. Likewise, the need to protect New Zealand’s native fauna has stimulated extensive research on alternative options for mitigating the effects of invasive predators, applicable to pest management problems in other countries.

The Glissonian Approach of the Hilum

Swiss Surgery ◽  
1999 ◽  
Vol 5 (3) ◽  
pp. 143-146 ◽  
Author(s):  
Launois ◽  
Maddern ◽  
Tay
Keyword(s):  
Portal Vein ◽  
Hepatic Artery ◽  
Posterior Approach ◽  
Hepatic Duct ◽  
Rapid Evolution ◽  
Hepatic Tissue ◽  
Detailed Knowledge ◽  
Porta Hepatis ◽  
Liver Segment ◽  
Glissonian Approach

The detailed knowledge of the segmental anatomy of the liver has led to a rapid evolution in resectional surgery based on the intrahepatic distribution of the portal trinity (the hepatic artery, hepatic duct and portal vein). The classical intrafascial or extrahepatic approach is to isolate the appropriate branch of the portal vein, hepatic artery and the hepatic duct, outside the liver substance. Another method, the extrafascial approach, is to dissect the whole sheath of the pedicle directly after division of a substantial amount of the hepatic tissue to reach the pedicle, which is surrounded by a sheath, derived from Glisson's capsule. This Glissonian sheath encloses the portal trinity. In the transfissural or intrahepatic approach, these sheaths can be approached either anteriorly (after division of the main, right or umbilical fissure) or posteriorly from behind the porta hepatis. We describe the technique for approaching the Glissonian sheath and hence the hepatic pedicle structures and their branches by the intrahepatic posterior approach that allows early delineation of the liver segment without the need for ancillary techniques. In addition, the indications for the use of this technique in the technical and oncologic settings are also discussed.

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