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

State-shifts of lion prey selection in the Kruger National Park

2017 ◽  
Vol 44 (1) ◽  
pp. 28 ◽  
Author(s):  
N. T. Maruping-Mzileni ◽  
P. J. Funston ◽  
S. M. Ferreira
Keyword(s):  
National Park ◽  
Prey Selection ◽  
Management Strategies ◽  
Stable State ◽  
Kruger National Park ◽  
Ecological Processes ◽  
Policy Makers ◽  
Predator Prey ◽  
Key Indicator ◽  
Management Interventions

Aims Indicators of pending state-shifts carry value for policy makers. Predator–prey relations reflect key ecological processes that shape ecosystems. Variance in predator–prey relations may serve as a key indicator of future state-shifts. Methods Lion (Panthera leo) diet in the Kruger National Park was evaluated as such an indicator. Over the three-decade time span reviewed, variance in diet in relation to rainfall, prey abundance, management strategies and disease emergence were reviewed. Key results Rainfall patterns, both seasonal and cyclical, were identified as key drivers of predator–prey selection. However, the intensity of management in the form of artificial waterpoints overrode and confounded natural process. The results suggest that savanna systems are stable and punctuated by climatic events in the form of extreme above-average rainfall that temporarily destabilises the system. However, droughts are a cyclical part of the savanna system. Conclusion Lion prey selection did fluctuate with changing environmental conditions. Abrupt state shifts did occur; however, the ecosystem returned to a stable state. Implications State shifts in ecosystems pose key challenges to conservation managers. State shifts appear to be primarily associated with management interventions and environmental factors.

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.

Prey Selection, Vertical Migrations and the Impacts of Harvesting Upon the Population Dynamics of a Predator-Prey System

2007 ◽  
Vol 69 (6) ◽  
pp. 1827-1846 ◽  
Author(s):  
Helen J. Edwards ◽  
Calvin Dytham ◽  
Jonathan W. Pitchford ◽  
David Righton
Keyword(s):  
Population Dynamics ◽  
Prey Selection ◽  
Predator Prey ◽  
Prey System

Frequency-dependent prey selection by larvae of Toxorhynchites splendens (Diptera: Culicidae)

1996 ◽  
Vol 86 (6) ◽  
pp. 633-639 ◽  
Author(s):  
D. Dominic Amalraj ◽  
P. K. Das
Keyword(s):  
Aedes Aegypti ◽  
Foraging Behaviour ◽  
Anopheles Stephensi ◽  
Prey Size ◽  
Prey Selection ◽  
Fourth Instar ◽  
Frequency Dependent ◽  
Size Selection ◽  
The Stability

AbstractThe foraging behaviour of frequency-dependent prey selection by larval instars of Toxorhynchites splendens (Wiedemann) was studied in the laboratory. Prey size selection (second vs fourth instars of Aedes aegypti Linnaeus or Anopheles stephensi Liston) by third and fourth instar predators was frequency-dependent. However, in the case of second instar predators, prey size selection was not frequency-dependent and the predator preferred second instar to fourth instar prey. When offered second instars of Aedes aegypti and Anopheles stephensi the preference for one species over the other was frequency-dependent in all the three predator instars. The role of frequency-dependent prey selection in the stability of prey—predator interaction at low equilibrium levels is discussed.

Prey selection by harbour seals, Phoca vitulina, in relation to variations in prey abundance

1997 ◽  
Vol 75 (9) ◽  
pp. 1508-1518 ◽  
Author(s):  
Dominic J. Tollit ◽  
Paul M. Thompson ◽  
Simon P. R. Greenstreet
Keyword(s):  
Diet Composition ◽  
Prey Size ◽  
Prey Selection ◽  
Phoca Vitulina ◽  
Correction Factors ◽  
Fish Prey ◽  
Size Selection ◽  
Harbour Seals ◽  
Moray Firth ◽  
Time Periods

This study compared the composition of the diet of harbour seals (Phoca vitulina) feeding in the Moray Firth, Scotland, with the abundance of their fish prey estimated from dedicated fishery surveys in January 1992 and 1994 and June 1992. Prey-size selection was also examined in these three time periods and in January 1991. In each period, the most abundant fish species contributed most to the diet. However, the relative abundances of the remaining species in the sea showed little similarity to their contribution to the seals' diet. Diet composition was almost totally dominated by either pelagic species or species dwelling on or strongly associated with the seabed, depending upon the relative abundance of pelagic schooling prey. Most fish consumed were 10–16 cm in length, although larger cod and herring were taken. With the exception of cod, the extent of size selection was dependent upon the use of correction factors that accounted for otolith erosion due to digestion.

Negative frequency-dependent prey selection by wolves and its implications on predator–prey dynamics

2021 ◽  
Vol 179 ◽  
pp. 247-265
Author(s):  
Sarah R. Hoy ◽  
Daniel R. MacNulty ◽  
Matthew C. Metz ◽  
Douglas W. Smith ◽  
Daniel R. Stahler ◽  
...  
Keyword(s):  
Prey Selection ◽  
Frequency Dependent ◽  
Predator Prey

A laboratory study of the feeding behavior of the rhabdocoel Mesostoma ehrenbergii on pond Cladocera

1982 ◽  
Vol 60 (6) ◽  
pp. 1305-1307 ◽  
Author(s):  
Steven S. Schwartz ◽  
Paul D. N. Hebert
Keyword(s):  
Feeding Behavior ◽  
Laboratory Study ◽  
Size Dependent ◽  
Prey Behavior ◽  
Cladoceran Species ◽  
Predation Rates

The predation rates of the rhabdocoel Mesostoma ehrenbergii were determined on a number of cladoceran species. Two means of capturing prey are employed by the flatworm but only active predation was explored in these experiments. It was found that this flatworm is a size-dependent predator with a preference for prey of about 1.2 mm. It was also observed that prey behavior was not an important factor in determining susceptibility to predation. M. ehrenbergii is a voracious predator; individuals consume more than 10 prey/day.

Prey Selection by Freshwater Predators with Different Foraging Strategies

1985 ◽  
Vol 42 (11) ◽  
pp. 1720-1732 ◽  
Author(s):  
Scott D. Cooper ◽  
Daniel W. Smith ◽  
James R. Bence
Keyword(s):  
Prey Selection ◽  
Foraging Strategies ◽  
Foraging Mode ◽  
Encounter Rates ◽  
Predator Prey ◽  
Anax Junius ◽  
Odonate Larvae ◽  
Selection For ◽  
Predator Foraging ◽  
Pachydiplax Longipennis

We observed several freshwater predators, including the odonate larvae Pachydiplax longipennis and Anax junius, the hemipterans Notonecta unifasciata and Buenoa scimitra, the dytiscid larva Acilius semisulcatus, and juvenile Gambusia affinis, feeding on a variety of microcrustacean prey and determined the frequency of the component parts of predator–prey interactions (encounter, attack, capture, ingestion). Encounter rates were the most important determinant of predator selectivity when predators were presented with a variety of microcrustacean prey. When only copepod species were used as prey, however, both encounter rates and capture success were important in determining predator diets. We used our data to test hypotheses concerning relationships between predator foraging mode and patterns of prey selection: mobile predators exhibited stronger selection for sedentary prey than did sit-and-wait predators; our own and literature data also indicated that macroinvertebrate sit-and-wait predators are better able to capture, and have higher selectivity for evasive prey than do mobile predators. A predator's attack acceleration, however, may be a better predictor of its selectivity for evasive versus nonevasive prey than its mean swimming speed.

scholarly journals Selective Feeding by a Predatory Sea Star Across a Depth Gradient in Northern Patagonia, Chile

2021 ◽  
Vol 8 ◽  
Author(s):  
Ignacio Garrido ◽  
Luis Miguel Pardo ◽  
Ladd E. Johnson ◽  
Dirk Schories
Keyword(s):  
Feeding Behavior ◽  
Prey Selection ◽  
Feeding Strategy ◽  
Benthic Communities ◽  
Generalist Predator ◽  
Subtidal Zone ◽  
Polar Regions ◽  
Depth Gradient ◽  
Sea Star ◽  
Sea Stars

Sea stars often function as keystone predators in food webs of intertidal and subtidal communities, especially in temperate and sub-polar regions. In South America the sea star Cosmasterias lurida is distributed along both the Atlantic and Pacific coasts of Patagonia and is one of the most conspicuous and abundant benthic predators in the shallow subtidal zone (<25 m). Its feeding strategy and prey selection are, however, still poorly known. This study describes the feeding behavior of C. lurida at a site in the Seno del Reloncaví (Chile), assessing its abundance, size and prey selection in the field relative to observed prey abundance and size along a bathymetric gradient. We hypothesized that C. lurida is a generalist predator, feeding on suitable prey according to their availability. However, we found that this predator only consumed a limited number (7 of 48) of potential prey species, primarily the slipper limpets Crepipatella spp. and the mussels Aulacomya ater and Mytilus chilensis. Electivity analysis revealed a clear preference for one mussel (A. ater) but not the other (M. chilensis) as well as depth-dependent selectivity for the slipper limpets, which changed from avoidance to preference with increasing depth. Sea star densities varied with depth, peaking between depths of 5 and 10 m, but the size of sea stars and the size of their prey did not vary significantly along a depth gradient. No significant correlations were found with the most commonly selected prey. These results would indicate that while this predator may be a generalist–opportunist, its feeding behavior is context-dependent and its high selectivity for certain species suggests that this sea star plays a key role structuring subtidal benthic communities in Patagonia.

scholarly journals Climate induced wolf prey selection in Yellowstone National Park, 1995-2015

2016 ◽  
Author(s):  
Douglas W Smith ◽  
Matthew Metz ◽  
Chris Wilmers ◽  
Daniel Stahler ◽  
Chris Geremia
Keyword(s):  
Yellowstone National Park ◽  
National Park ◽  
Prey Selection ◽  
Selective Advantage ◽  
Late Winter ◽  
Age Classes ◽  
Predator Prey ◽  
Wolf Predation ◽  
Management Objectives

Prey selection by wolves has been a fundamental and long-term topic of interest for wolf-prey studies. Virtually all studies conclude the selectivity of wolf predation and typically identify what made an individual vulnerable. Vulnerability, however, varies for multiple reasons and emerging research is discovering climate induced effects on prey forage altering condition and selective advantage of migration. We present data from a twenty year study of wolf-elk predation in Yellowstone National Park (YNP) which found bull elk killed more frequently in early winter after years with less snowfall compared to years with normal snowfall. Snowfall impacted summer forage, which impacted bull elk condition going into the autumn rut, which weakened elk prematurely post-rut causing them to be selected by wolves in early rather than late winter, and possibly caused more bulls to be killed overall. Bull elk ratios have declined over the last 20 years (from 40-60 to 10-15 bulls/100 cows; lower outside YNP), which has led to calls for a reduced human harvest on bulls which has been met with significant resistance. Understanding the interaction between climate, forage and wolf predation on bull elk (and other sex/age classes) will help guide management decisions and potentially sustain hunting of bulls in the long term as well as protect natural management objectives within YNP. Results will be of widespread value as they may suggest changing predator-prey dynamics across North America by making some otherwise healthy prey vulnerable to predation.

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