Long- versus short-range foraging strategies of hoary (Lasiurus cinereus) and silver-haired (Lasionycteris noctivagans) bats and the consequences for prey selection

1985 ◽  
Vol 63 (11) ◽  
pp. 2507-2515 ◽  
Author(s):  
Robert M. R. Barclay
Keyword(s):  
Short Range ◽  
Prey Availability ◽  
Prey Selection ◽  
Foraging Strategy ◽  
Foraging Strategies ◽  
Lasiurus Cinereus ◽  
Echolocation Calls ◽  
Straight Line ◽  
Lasionycteris Noctivagans ◽  
Selection Of

Habitat use, temporal activity, foraging behaviour, and prey selection of hoary bats (Lasiurus cinereus) and silver-haired bats (Lasionycteris noctivagans) were studied at Delta Marsh, Manitoba. Bat activity was assessed by monitoring echolocation calls with ultrasonic detectors. Prey availability was determined using sticky and Malaise traps and dietary information was obtained from fecal analysis. Both species were active all night and foraged primarily in the lee of a narrow forested ridge. Lasionycteris noctivagans foraged in a manner that indicates that it detects and pursues prey over short distances. These bats fly slowly, are highly manoeuverable, and were commonly observed feeding on swarms of insects in small clearings. They use echolocation calls that support the notion of a short-range foraging strategy and feed opportunistically on whatever insects are available. Lasiurus cinereus, on the other hand, uses a long-range prey detection and pursuit foraging strategy. They fly rapidly along straight line paths in open areas and use echolocation calls designed to detect insects at a distance. The diet consists primarily of large insects (moths, beetles, and dragonflies), but the bats nonetheless feed opportunistically. The foraging strategy likely restricts the availability and profitability of small insects as prey.

The echolocation calls of hoary (Lasiurus cinereus) and silver-haired (Lasionycteris noctivagans) bats as adaptations for long- versus short-range foraging strategies and the consequences for prey selection

1986 ◽  
Vol 64 (12) ◽  
pp. 2700-2705 ◽  
Author(s):  
Robert M. R. Barclay
Keyword(s):  
Prey Selection ◽  
Foraging Strategy ◽  
Prey Detection ◽  
Constant Frequency ◽  
Insectivorous Bats ◽  
Lasiurus Cinereus ◽  
Echolocation Calls ◽  
Close Range ◽  
Search Approach ◽  
Lasionycteris Noctivagans

Amongst aerial-feeding insectivorous bats, differences in the design of echolocation calls appear to be associated with differences in foraging strategy. Recordings and observations of hoary (Lasiurus cinereus) and silver-haired (Lasionycteris noctivagans) bats in Manitoba, Canada, support such an association. Lasionycteris noctivagans use multiharmonic search–approach calls with an initial frequency sweep and a constant frequency tail. Such calls are suited for bats foraging in the open but near obstacles, and pursuing prey detected at relatively close range. This is the foraging strategy employed by this relatively slow, manoeuverable species. Lasiurus cinereus employ single harmonic search–approach calls that are low (20–17 kHz), essentially constant frequency signals. Calls of this design are suited for long-range target detection in open air situations, the foraging strategy used by L. cinereus. Differences in call design may explain dietary differences between the two species. Lasiurus cinereus consistently prey on large insects. The low, constant frequency design of their calls means that small insects are detectable only at close range and are thus difficult for this fast-dying bat to catch. The broad-band calls used by L. noctivagans do not restrict prey detection and these bats prey on a wider range of insects. Similar restrictions on prey detection, caused by echolocation call specializations, may be important in producing what might otherwise be considered active prey selection by some insectivorous bats.

Bats of Kootenay, Glacier, and Mount Revelstoke national parks in Canada: identification by echolocation calls, distribution, and biology

1983 ◽  
Vol 61 (11) ◽  
pp. 2503-2508 ◽  
Author(s):  
M. B. Fenton ◽  
H. G. Merriam ◽  
G. L. Holroyd
Keyword(s):  
British Columbia ◽  
National Parks ◽  
National Park ◽  
Myotis Lucifugus ◽  
Glacier National Park ◽  
Lasiurus Cinereus ◽  
Echolocation Calls ◽  
Bat Activity ◽  
Lasionycteris Noctivagans ◽  
The Town

We studied the behaviour, echolocation calls, and distribution of bats in Kootenay, Glacier, and Mount Revelstoke national parks in British Columbia, Canada. Presented here are keys for identification of nine species of bats by their echolocation calls as rendered by two different bat-detecting systems. The species involved include Myotis lucifugus, M. evotis, M. volans, M. septentrionalis, M. californicus, Lasionycteris noctivagans, Eptesicus fuscus, Lasiurus cinereus, and L. borealis. The distribution of these species within the three parks was assessed by capturing bats in traps and mist nets and by monitoring of their echolocation calls. Most of the species exploited concentrations of insects around spotlights, providing convenient foci of activity for assessing distribution. Although most species of Myotis were commonly encountered away from the lights, Lasiurus cinereus in Kootenay National Park was only regularly encountered feeding on insects at lights. This species was not detected in Glacier National Park, and although we regularly encountered it in the town of Revelstoke, it was rarely encountered in Mount Revelstoke National Park. Another focus of bat activity was small pools in cedar forest in Mount Revelstoke National Park. This involved high levels of Myotis spp. activity at dusk as the bats came to the pools to drink.

Feeding behaviour of the common dolphinfish Coryphaena hippurus: older fish use more complex foraging strategies

2015 ◽  
Vol 95 (6) ◽  
pp. 1277-1284 ◽  
Author(s):  
José De Anchieta C.C. Nunes ◽  
Renato H. A. Freitas ◽  
José A. Reis-Filho ◽  
Miguel Loiola ◽  
Cláudio L.S. Sampaio
Keyword(s):  
Feeding Behaviour ◽  
Visual Cues ◽  
Prey Availability ◽  
Learning Experience ◽  
Foraging Strategy ◽  
Foraging Strategies ◽  
Size Classes ◽  
Coryphaena Hippurus ◽  
The Common ◽  
Floating Objects

The common dolphinfish (Coryphaena hippurus) is widely distributed and represents an important part of the currently exploited fishery resources. This species’ feeding behaviour, however, is poorly understood. This study aimed to investigate the feeding behaviour of dolphinfish and the effect of body size (and the consequently aggregated learning experience) on the strategies used for capturing their prey. Observations were made from an oil platform in north-eastern Brazil. Dolphinfish length was visually estimated and classified into three size classes. The following foraging strategies were observed in our study: ‘active chasing’, ‘leaping out’, ‘swimming in circles’, ‘surf’, ‘using floating objects’ and ‘cleaning turtle carapaces’. The most frequently used foraging strategy was ‘active chasing’, suggesting a strong preference of dolphinfish in using visual cues during predation. Smaller size-classes of dolphinfish did not perform the ‘swimming in circles’ and ‘surf’ strategy, probably due to a lack of learning experience, since further social interactions could be needed in order to show this strategy. Smaller dolphinfish regularly showed the ‘using floating objects’ as a foraging strategy, probably reflecting an opportunistic behaviour. The smallest individuals were using more simple strategies, to chase smaller prey that could have different and less complex escape strategies. It indicates learning experience could play an important role into the dolphinfish ontogeny, moving towards more complex foraging strategies throughout their lives. Independently of the age class, the dolphinfish displayed a varied repertory of foraging strategies, maximizing hunting success in the open ocean, a hostile pelagic environment with a low prey availability.

The influence of structural clutter on activity patterns of insectivorous bats

1997 ◽  
Vol 75 (1) ◽  
pp. 131-136 ◽  
Author(s):  
R. M. Brigham ◽  
S. D. Grindal ◽  
M. C. Firman ◽  
J. L. Morissette
Keyword(s):  
Prey Availability ◽  
Activity Patterns ◽  
Three Dimensional ◽  
Habitat Type ◽  
Habitat Choice ◽  
Insectivorous Bats ◽  
Lasiurus Cinereus ◽  
Direct Contrast ◽  
And Control ◽  
Lasionycteris Noctivagans

We experimentally tested the hypothesis that three-dimensional structural clutter is a major factor affecting habitat choice by insectivorous bats. To do this we artificially increased clutter at two sites used by bats without affecting prey availability. Our measure of available insect prey did not differ between treatment and control sites, indicating that only the spatial complexity of the habitat type was manipulated. Artificial clutter negatively affected foraging activity by small bats (Myotis spp.), supporting the hypothesis that physical clutter does affect foraging by bats. In direct contrast to our expectation, large bats (Eptesicus fuscus, Lasiurus cinereus, Lasionycteris noctivagans) were apparently unaffected by the clutter treatment. We suggest that this may be an artifact of our experimental design, because our ultrasonic detectors probably recorded large bats flying above the artificial clutter.

The diet of the insectivorous Hawaiian hoary bat (Lasiurus cinereus semotus) in an open and a cluttered habitat

1999 ◽  
Vol 77 (10) ◽  
pp. 1603-1608 ◽  
Author(s):  
David S Jacobs
Keyword(s):  
Foraging Strategy ◽  
Foraging Efficiency ◽  
Insect Fauna ◽  
Detection Range ◽  
Lasiurus Cinereus ◽  
Echolocation Calls ◽  
Insect Prey ◽  
Open Habitat ◽  
Hoary Bat ◽  
Lasiurus Cinereus Semotus

The Hawaiian hoary bat, Lasiurus cinereus semotus, foraged in both an open and a cluttered habitat. In the cluttered habitat it used slow, manoeuvring flight. In the open habitat it used rapid, less manoeuvring flight with echolocation calls of higher frequency than in the cluttered habitat. The combination of faster flight with higher frequency echolocation calls means that it should detect insect prey too late to manoeuvre for capture unless it preyed on relatively larger insects in the open habitat. The mean size of dietary items should therefore be greater in the open habitat than in the cluttered habitat. There should also be a greater preponderance of larger insects in the open than in the cluttered habitat to ensure that the use of rapid flight with higher frequency echolocation calls is efficient. I tested these predictions by comparing the diets and insect fauna in one open site with those in one closed site on the island of Hawai'i. As predicted, the dietary items were larger (t = 60.9, df = 259, p < 0.00001) in the open habitat (length = 18.9 ± 1.3 mm (mean ± SD); range 14-24 mm) than in the cluttered habitat (6.5 ± 1.6 mm; range 4-15 mm). In the cluttered habitat 86% of the insects fell into the three smallest length categories, while 52% of the insects in the open habitat fell into the two largest length categories. The preponderance of larger insects in the open habitat, with the consequent increase in detection range, enabled the bats to increase their flight speed despite their use of higher frequency echolocation calls. Rapid flight increases the rate at which insect prey are encountered and improves the foraging efficiency of bats. This provides evidence that bats are capable of altering their foraging strategy in response to prey characteristics and not just to the physical environment.

scholarly journals Chemical Cues from Entomopathogenic Nematodes Vary Across Three Species with Different Foraging Strategies, Triggering Different Behavioral Responses in Prey and Competitors

2021 ◽  
Author(s):  
John M. Grunseich ◽  
Natalie M. Aguirre ◽  
Morgan N. Thompson ◽  
Jared G. Ali ◽  
Anjel M. Helms
Keyword(s):  
Entomopathogenic Nematodes ◽  
Chemical Cues ◽  
Prey Availability ◽  
Foraging Strategy ◽  
Foraging Strategies ◽  
Predator Species ◽  
Hunting Strategies ◽  
Prey Behavior ◽  
Cucumber Beetle ◽  
Predator Foraging

AbstractChemical cues play important roles in predator–prey interactions. Semiochemicals can aid predator foraging and alert prey organisms to the presence of predators. Previous work suggests that predator traits differentially influence prey behavior, however, empirical data on how prey organisms respond to chemical cues from predator species with different hunting strategies, and how foraging predators react to cues from potential competitors, is lacking. Furthermore, most research in this area has focused on aquatic and aboveground terrestrial systems, while interactions among belowground, soiling-dwelling organisms have received relatively little attention. Here, we assessed how chemical cues from three species of entomopathogenic nematodes (EPNs), each with a different foraging strategy, influenced herbivore (cucumber beetle) and natural enemy (EPN) foraging behavior. We predicted these cues could serve as chemical indicators of increased predation risk, prey availability, or competition. Our findings revealed that foraging cucumber beetle larvae avoided chemical cues from Heterorhabditis bacteriophora (active-foraging cruiser EPNs), but not Steinernema carpocapsae (ambusher EPNs) or Steinernema riobrave (intermediate-foraging EPNs). In contrast, foraging H. bacteriophora EPNs were attracted to cues produced by the two Steinernema species but not conspecific cues. Notably, the three EPN species produced distinct blends of olfactory cues, with only a few semi-conserved compounds across species. These results indicate that a belowground insect herbivore responds differently to chemical cues from different EPN species, with some EPN species avoiding prey detection. Moreover, the active-hunting EPNs were attracted to heterospecific cues, suggesting these cues indicate a greater probability of available prey, rather than strong interspecific competition.

Diet composition and prey selection of vendace Coregonus albula in the mesotrophic, temperate Lake Ostrowite (Northern Poland)

2008 ◽  
Vol 37 (1) ◽  
Author(s):  
Tomasz Kakareko ◽  
Paweł Napiórkowski ◽  
Jacek Kozłowski
Keyword(s):  
Diet Composition ◽  
Prey Selection ◽  
Temperate Lake ◽  
Coregonus Albula ◽  
Northern Poland ◽  
Mesotrophic Lake ◽  
Selection Of

Diet composition and prey selection of vendaceLake Ostrowite is a mesotrophic lake in Northern Poland 280.7 ha in area and 43 m deep at its deepest point. To study vendace (

scholarly journals Be different to be better: the effect of personality on optimal foraging with incomplete knowledge

2021 ◽  
Author(s):  
Poppy M. Jeffries ◽  
Samantha C. Patrick ◽  
Jonathan R. Potts
Keyword(s):  
Optimal Foraging ◽  
Optimal Foraging Theory ◽  
Foraging Strategy ◽  
Foraging Strategies ◽  
Partial Knowledge ◽  
Marginal Value ◽  
Animal Populations ◽  
Plausible Mechanism ◽  
Insight Into ◽  
Modelling Approach

AbstractMany animal populations include a diversity of personalities, and these personalities are often linked to foraging strategy. However, it is not always clear why populations should evolve to have this diversity. Indeed, optimal foraging theory typically seeks out a single optimal strategy for individuals in a population. So why do we, in fact, see a variety of strategies existing in a single population? Here, we aim to provide insight into this conundrum by modelling the particular case of foraging seabirds, that forage on patchy prey. These seabirds have only partial knowledge of their environment: they do not know exactly where the next patch will emerge, but they may have some understanding of which locations are more likely to lead to patch emergence than others. Many existing optimal foraging studies assume either complete knowledge (e.g. Marginal Value Theorem) or no knowledge (e.g. Lévy Flight Hypothesis), but here we construct a new modelling approach which incorporates partial knowledge. In our model, different foraging strategies are favoured by different birds along the bold-shy personality continuum, so we can assess the optimality of a personality type. We show that it is optimal to be shy (resp. bold) when living in a population of bold (resp. shy) birds. This observation gives a plausible mechanism behind the emergence of diverse personalities. We also show that environmental degradation is likely to favour shyer birds and cause a decrease in diversity of personality over time.

scholarly journals Diving deep into trouble: the role of foraging strategy and morphology in adapting to a changing environment

2020 ◽  
Vol 8 (1) ◽  
Author(s):  
Monique Ladds ◽  
David Rosen ◽  
Carling Gerlinsky ◽  
David Slip ◽  
Robert Harcourt
Keyword(s):  
Foraging Strategy ◽  
Central Place ◽  
Dive Duration ◽  
Foraging Strategies ◽  
Body Morphology ◽  
Sea Lions ◽  
Fur Seals ◽  
Adequate Food ◽  
Physiological Capacity ◽  
Total Body Oxygen

Abstract Physiology places constraints on an animal’s ability to forage and those unable to adapt to changing conditions may face increased challenges to reproduce and survive. As the global marine environment continues to change, small, air-breathing, endothermic marine predators such as otariids (fur seals and sea lions) and particularly females, who are constrained by central place foraging during breeding, may experience increased difficulties in successfully obtaining adequate food resources. We explored whether physiological limits of female otariids may be innately related to body morphology (fur seals vs sea lions) and/or dictate foraging strategies (epipelagic vs mesopelagic or benthic). We conducted a systematic review of the increased body of literature since the original reviews of Costa et al. (When does physiology limit the foraging behaviour of freely diving mammals? Int Congr Ser 2004;1275:359–366) and Arnould and Costa (Sea lions in drag, fur seals incognito: insights from the otariid deviants. In Sea Lions of the World Fairbanks. Alaska Sea Grant College Program, Alaska, USA, pp. 309–324, 2006) on behavioural (dive duration and depth) and physiological (total body oxygen stores and diving metabolic rates) parameters. We estimated calculated aerobic dive limit (cADL—estimated duration of aerobic dives) for species and used simulations to predict the proportion of dives that exceeded the cADL. We tested whether body morphology or foraging strategy was the primary predictor of these behavioural and physiological characteristics. We found that the foraging strategy compared to morphology was a better predictor of most parameters, including whether a species was more likely to exceed their cADL during a dive and the ratio of dive time to cADL. This suggests that benthic and mesopelagic divers are more likely to be foraging at their physiological capacity. For species operating near their physiological capacity (regularly exceeding their cADL), the ability to switch strategies is limited as the cost of foraging deeper and longer is disproportionally high, unless it is accompanied by physiological adaptations. It is proposed that some otariids may not have the ability to switch foraging strategies and so be unable adapt to a changing oceanic ecosystem.

Separation of active and passive components of short-range stiffness of muscle

1977 ◽  
Vol 232 (1) ◽  
pp. 45-49 ◽  
Author(s):  
D. L. Morgan
Keyword(s):  
Short Range ◽  
Muscle Tension ◽  
Isometric Tension ◽  
Incomplete Fusion ◽  
Low Frequencies ◽  
Passive Components ◽  
Stimulus Rate ◽  
Straight Line ◽  
Wide Range ◽  
Tendon Compliance

The short-range stiffness of smoothly but submaximally contracting isometric soleus muscles of anesthetised cats was measured by applying small fast stretches. The ratio of isometric tension to stiffness was plotted against tension over a wide range of muscle lengths and stimulus rates. The results fitted a straight line well, as predicted from crossbridge theory, showing the stiffness to be a function of tension only, independent of the combination of length and stimulus rate used to generate the tension. The major deviation from this line was attributed to incomplete fusion at low frequencies of stimulation. Values believed to be tendon compliance and crossbridge tension per unit of stiffness were found from the graph, and the tendon compliance correlated with the maximum muscle tension. Shortening the tendon by attaching nearer to the muscle changed the results in a manner consistent with the theory, provided that appropriate precautions were taken against slippage.

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