scholarly journals Predicting the ecological impacts of a new freshwater invader: functional responses and prey selectivity of the ‘killer shrimp’,Dikerogammarus villosus, compared to the nativeGammarus pulex

2013 ◽  
Vol 59 (2) ◽  
pp. 337-352 ◽  
Author(s):  
Jennifer A. Dodd ◽  
Jaimie T. A. Dick ◽  
Mhairi E. Alexander ◽  
Calum MacNeil ◽  
Alison M. Dunn ◽  
...  
Keyword(s):  
Ecological Impacts ◽  
Prey Selectivity ◽  
Functional Responses ◽  
Dikerogammarus Villosus

Ecological impacts of an invasive predator explained and predicted by comparative functional responses

2012 ◽  
Vol 15 (4) ◽  
pp. 837-846 ◽  
Author(s):  
Jaimie T. A. Dick ◽  
Kevin Gallagher ◽  
Suncica Avlijas ◽  
Hazel C. Clarke ◽  
Susan E. Lewis ◽  
...  
Keyword(s):  
Ecological Impacts ◽  
Functional Responses ◽  
Invasive Predator

Prey selectivity of wolves in Banff National Park. I. Prey species

1993 ◽  
Vol 71 (1) ◽  
pp. 130-139 ◽  
Author(s):  
David J. Huggard
Keyword(s):  
National Park ◽  
Prey Type ◽  
Prey Selectivity ◽  
Functional Responses ◽  
Encounter Rates ◽  
Factors Affecting ◽  
Habitat Overlap ◽  
Banff National Park ◽  
Mountain Goats ◽  
Number Of Individuals

I examined the components generating selectivity in wolves preying on five ungulate species in Banff National Park, Alberta. Overall selectivity for elk and deer species, and apparent avoidance of bighorn sheep and mountain goats, were due primarily to lower habitat overlap of wolves with the latter two species, and therefore lower encounter rates. For social ungulates, I argue that the herd should be considered the unit of encounter, with encounter rates proportional to the number of herds rather than the number of individuals. However, large herds predictably associated with certain areas may be visited intentionally by wolves, increasing effective encounter rates. Foraging theory suggests that all ungulate prey should be equally profitable to wolves upon encounter and therefore the factors affecting encounter rates are critical in determining prey selectivity. A simple model incorporating different habitat overlap, herd sizes, and predictable herds predicts qualitatively different functional responses of wolves to changes in density of the different prey types. The model also demonstrates how apparent selectivity for a prey type can result from the different ways in which prey are encountered.

scholarly journals Comparison of the functional responses of invasive and native amphipods

2007 ◽  
Vol 4 (2) ◽  
pp. 166-169 ◽  
Author(s):  
Loic Bollache ◽  
Jaimie T.A Dick ◽  
Keith D Farnsworth ◽  
W. Ian Montgomery
Keyword(s):  
Invasive Species ◽  
North America ◽  
Invasion Biology ◽  
Type Ii ◽  
Trophic Groups ◽  
Functional Responses ◽  
Dikerogammarus Villosus

While we can usually understand the impacts of invasive species on recipient communities, invasion biology lacks methodologies that are potentially more predictive. Such tools should ideally be straightforward and widely applicable. Here, we explore an approach that compares the functional responses (FRs) of invader and native amphipod crustaceans. Dikerogammarus villosus is a Ponto-Caspian amphipod currently invading Europe and poised to invade North America. Compared with other amphipods that it actively replaces in freshwaters, D. villosus exhibited significantly greater predation, consuming significantly more prey with a higher type II FR. This corroborates the known dramatic field impacts of D. villosus on invaded communities. In another species, FRs were nearly identical in invasive and native ranges. We thus propose that if FRs of other taxa and trophic groups follow such general patterns, this methodology has potential in predicting future invasive species impacts.

scholarly journals Assessing the relative potential ecological impacts and invasion risks of emerging and future invasive alien species

NeoBiota ◽  
2018 ◽  
Vol 40 ◽  
pp. 1-24 ◽  
Author(s):  
James W.E. Dickey ◽  
Ross N. Cuthbert ◽  
Michael Rea ◽  
Ciaran Laverty ◽  
Kate Crane ◽  
...  
Keyword(s):  
Alien Species ◽  
Attack Rate ◽  
Feeding Rate ◽  
Invasive Alien Species ◽  
Propagule Pressure ◽  
Ecological Impacts ◽  
Economic Damage ◽  
Functional Responses ◽  
Invasion Risk ◽  
Pet Trade

Invasive alien species (IAS) cause myriad negative impacts, such as ecosystem disruption, human, animal and plant health issues, economic damage and species extinctions. There are many sources of emerging and future IAS, such as the poorly regulated international pet trade. However, we lack methodologies to predict the likely ecological impacts and invasion risks of such IAS which have little or no informative invasion history. This study develops the Relative Impact Potential (RIP) metric, a new measure of ecological impact that incorporates per capita functional responses (FRs) and proxies for numerical responses (NRs) associated with emerging invaders. Further, as propagule pressure is a determinant of invasion risk, we combine the new measure of Pet Propagule Pressure (PPP) with RIP to arrive at a second novel metric, Relative Invasion Risk (RIR). We present methods to calculate these metrics and to display the outputs on intuitive bi- and triplots. We apply RIP/RIR to assess the potential ecological impacts and invasion risks of four commonly traded pet turtles that represent emerging IAS: Trachemysscriptascripta, the yellow-bellied slider; T.s.troostii, the Cumberland slider; Sternotherusodoratus, the common musk turtle; and Kinosternonsubrubrum, the Eastern mud turtle. The high maximum feeding rate and high attack rate of T.s.scripta, combined with its numerical response proxies of lifespan and fecundity, gave it the highest impact potential. It was also the second most readily available according to our UK surveys, indicating a high invasion risk. Despite having the lowest maximum feeding rate and attack rate, S.odoratus has a high invasion risk due to high availability and we highlight this species as requiring monitoring. The RIP/RIR metrics offer two universally applicable methods to assess potential impacts and risks associated with emerging and future invaders in the pet trade and other sources of future IAS. These metrics highlight T.s.scripta as having high impact and invasion risk, corroborating its position on the EU list of 49 IAS of Union Concern. This suggests our methodology and metrics have great potential to direct future IAS policy decisions and management. This, however, relies on collation and generation of new data on alien species functional responses, numerical responses and their proxies, and imaginative measures of propagule pressure.

scholarly journals Comparative Functional Responses Predict the Invasiveness and Ecological Impacts of Alien Herbivorous Snails

PLoS ONE ◽  
2016 ◽  
Vol 11 (1) ◽  
pp. e0147017 ◽  
Author(s):  
Meng Xu ◽  
Xidong Mu ◽  
Jaimie T. A. Dick ◽  
Miao Fang ◽  
Dangen Gu ◽  
...  
Keyword(s):  
Ecological Impacts ◽  
Functional Responses

scholarly journals Existing and emerging high impact invasive species are characterized by higher functional responses than natives

2014 ◽  
Vol 10 (2) ◽  
pp. 20130946 ◽  
Author(s):  
Mhairi E. Alexander ◽  
Jaimie T. A. Dick ◽  
Olaf L. F. Weyl ◽  
Tamara B. Robinson ◽  
David M. Richardson
Keyword(s):  
Invasive Species ◽  
Micropterus Salmoides ◽  
Clarias Gariepinus ◽  
Research Priorities ◽  
Ecological Impacts ◽  
Feeding Rates ◽  
Functional Responses ◽  
Native Communities ◽  
Prey Handling ◽  
Invader Impact

Predicting ecological impacts of invasive species and identifying potentially damaging future invaders are research priorities. Since damage by invaders is characterized by their depletion of resources, comparisons of the ‘functional response’ (FR; resource uptake rate as a function of resource density) of invaders and natives might predict invader impact. We tested this by comparing FRs of the ecologically damaging ‘world's worst’ invasive fish, the largemouth bass ( Micropterus salmoides ), with a native equivalent, the Cape kurper ( Sandelia capensis ), and an emerging invader, the sharptooth catfish ( Clarias gariepinus ), with the native river goby ( Glossogobius callidus ), in South Africa, a global invasion hotspot . Using tadpoles ( Hyperolius marmoratus ) as prey, we found that the invaders consumed significantly more than natives. Attack rates at low prey densities within invader/native comparisons reflected similarities in predatory strategies; however, both invasive species displayed significantly higher Type II FRs than the native comparators. This was driven by significantly lower prey handling times by invaders, resulting in significantly higher maximum feeding rates. The higher FRs of these invaders are thus congruent with, and can predict, their impacts on native communities. Comparative FRs may be a rapid and reliable method for predicting ecological impacts of emerging and future invasive species.

scholarly journals Pushing the switch: functional responses and prey switching by invasive lionfish may mediate their ecological impact

2021 ◽  
Author(s):  
Monica McCard ◽  
Josie South ◽  
Ross N. Cuthbert ◽  
James W. E. Dickey ◽  
Nathan McCard ◽  
...  
Keyword(s):  
Functional Response ◽  
Prey Species ◽  
Effective Means ◽  
Ecological Impact ◽  
Artemia Salina ◽  
Ecological Impacts ◽  
Feeding Rates ◽  
Functional Responses ◽  
Prey Switching ◽  
Frequency Dependent

AbstractBiodiversity is declining on a global scale and the spread of invasive alien species (IAS) is a major driver, particularly through predatory impacts. Thus, effective means of assessing and predicting the consequences of IAS predation on native prey population stability remains a vital goal for conservation. Here, we applied two classic ecological concepts, consumer functional response (FR) and prey switching, to predict and understand the ecological impacts of juveniles of the lionfish (Pterois volitans), a notorious and widespread marine invader. Functional responses and prey switching propensities were quantified towards three representative prey species: Artemia salina, Palaemonetes varians, and Gammarus oceanicus. Lionfish exhibited potentially destabilising Type II FRs towards individual prey species, owing to high consumption rates at low prey densities, whilst FR magnitudes differed among prey species. Functional response attack rates (a) were highest, and handling times (h) lowest, towards A. salina, followed by P. varians and then G. oceanicus. Maximum feeding rates (1/h) and functional response ratios (FRR; a/h) also followed this impact gradient for the three prey species. Lionfish, however, displayed a potentially population stabilising prey switching propensity (i.e. frequency-dependent predation) when multiple prey species were presented simultaneously, where disproportionately less of rare prey, and more of abundant prey, were consumed. Whilst FR and FRR magnitudes indicate marked per capita lionfish predatory impacts towards prey species, a strong prey switching propensity may reduce in-field impacts by offering low density prey refuge in biodiverse communities. Our results thus corroborate field patterns documenting variable impacts of lionfish, with prey extirpations less likely in diverse communities owing to frequency-dependent predation.

scholarly journals Warming mediates intraspecific multiple predator effects from an invasive crustacean

2021 ◽  
Vol 168 (3) ◽  
Author(s):  
Ross N. Cuthbert ◽  
Ryan J. Wasserman ◽  
Tatenda Dalu ◽  
Elizabeta Briski
Keyword(s):  
Alien Species ◽  
Trophic Interactions ◽  
Invasive Alien Species ◽  
Ecological Impacts ◽  
Feeding Rates ◽  
Functional Responses ◽  
Multiple Predator Effects ◽  
Predator Interactions ◽  
The Impact ◽  
Predator Effects

AbstractInvasive alien species impacts might be mediated by environmental factors such as climatic warming. For invasive predators, multiple predator interactions could also exacerbate or dampen ecological impacts. These effects may be especially pronounced in highly diverse coastal ecosystems that are prone to profound and rapid regime shifts. We examine emergent effects of warming on the strength of intraspecific multiple predator effects from a highly successful invasive gammarid Gammarus tigrinus, using a functional response approach towards larval chironomids (feeding rates under different prey densities). Single predator maximum feeding rates were three-times higher at 24 °C compared to 18 °C overall, with potentially prey destabilising type II functional responses exhibited. However, pairs of gammarids exhibited intraspecific multiple predator effects that were in turn mediated by temperature regime, whereby synergisms were found at the lower temperature (i.e. positive non-trophic interactions) and antagonisms detected at the higher temperature (i.e. negative non-trophic interactions) under high prey densities. Accordingly, warming scenarios may worsen the impact of this invasive alien species, yet implications of temperature change are dependent on predator–predator interactions. Emergent effects between abiotic and biotic factors should be considered in ecological impact predictions across habitat types for invasive alien species.

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