Acoustic basis for fish prey selection by echolocating odontocetes

2004 ◽  
Vol 116 (4) ◽  
pp. 2503-2504
Author(s):  
Whitlow W. L. Au ◽  
Kelly J. Benoit‐Bird ◽  
Ronald Kastelein ◽  
Sander van de Heul
Keyword(s):  
Prey Selection ◽  
Fish Prey

Diel feeding and prey selection of three size classes of shortfinned eel (Anguilla australis) in New Zealand

1998 ◽  
Vol 49 (5) ◽  
pp. 421 ◽  
Author(s):  
P. M. Sagar ◽  
G. J. Glova
Keyword(s):  
New Zealand ◽  
Prey Selection ◽  
Microhabitat Use ◽  
Night Time ◽  
Fish Prey ◽  
Size Classes ◽  
Anguilla Australis ◽  
Selection Indices ◽  
Feeding Periodicity ◽  
Selection Of

Benthic macroinvertebrates and three size classes of shortfinned eel (Anguilla australis, Anguillidae) were sampled in a lowland New Zealand stream over a 24-h period in summer to investigate diel feeding periodicity and prey selection. Fish of all three size classes fed mostly from post-dusk to dawn, with larger fish tending to consume a greater proportion of their prey during night-time. The number of prey taxa consumed increased with increasing size of fish. Prey selection indices indicated that: (1) the smallest eels (80–100 mm total length, TL) preferentially consumed ostracods (Crustacea) and larvae of Chironomidae (Diptera) and Psilochorema sp. (free-living Trichoptera); (2) medium-sized eels (101–199 mm TL) preferred larvae of Chironomidae, and Costachorema sp., Hydrobiosis sp. and Psilochorema sp.; and (3) large eels (200–300 mm TL) preferred ostracods, Psilochorema sp. and Hudsonema amabilis (cased Trichoptera). Eels of all size classes showed selection for soft-bodied or easily broken prey over those with hard cases which would have been more difficult to digest. There was considerable overlap in the diets of medium and large eels. Differences in the timing of feeding between the three size classes of eel are explained in terms of microhabitat use; differences in diet are explained in terms of prey size, and are also related to eel size.

Fish Prey Selection by the Common KingfisherAlcedo atthisin Northern Iberia

2012 ◽  
Vol 47 (2) ◽  
pp. 169-177 ◽  
Author(s):  
Antonio Vilches ◽  
Rafael Miranda ◽  
Juan Arizaga
Keyword(s):  
Prey Selection ◽  
Fish Prey ◽  
The Common

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.

Foraging by a young-of-the-year piscivore: the role of predator size, prey type, and density

2005 ◽  
Vol 62 (10) ◽  
pp. 2330-2342 ◽  
Author(s):  
Tracy L Galarowicz ◽  
David H Wahl
Keyword(s):  
Benthic Invertebrates ◽  
Prey Selection ◽  
Handling Time ◽  
Prey Type ◽  
Benthic Invertebrate ◽  
Ontogenetic Changes ◽  
Functional Responses ◽  
Fish Prey ◽  
Young Of The Year ◽  
Diet Shifts

Young-of-the-year piscivores undergo ontogenetic diet shifts, but mechanisms influencing prey selection and implications for growth are unclear. We examined foraging and growth of 20- to 150-mm walleye (Sander vitreus) fed either zooplankton, benthic invertebrates, or fish over a range of prey densities in the laboratory. The number of each prey type consumed was influenced by walleye size and prey density. Walleye exhibited type II functional responses on each prey type; attack coefficients were constant across zooplankton and fish densities but decreased with benthic invertebrate densities. Handling time estimates were greater for fish than for other prey types but similar for zooplankton and benthos. Foraging efficiencies on zooplankton and benthic invertebrates increased with walleye size but were variable for fish prey. The smallest walleye size class (20 mm) had similar energy return (J·min–1) and growth (g·day–1) on zooplankton, benthic invertebrates, and fish. For larger walleye, both energy return and growth were highest on fish, intermediate on benthic invertebrates, and lowest on zooplankton. Diet shifts of juvenile piscivores and, consequently, growth can be explained by ontogenetic changes in foraging abilities and prey densities.

Foraging behavior, morphology, and life history variation determine the ontogeny of piscivory in two closely related predators

2005 ◽  
Vol 62 (9) ◽  
pp. 2010-2020 ◽  
Author(s):  
Brian DS Graeb ◽  
Tracy Galarowicz ◽  
David H Wahl ◽  
John M Dettmers ◽  
Mathew J Simpson
Keyword(s):  
Life History ◽  
Feeding Behavior ◽  
Yellow Perch ◽  
Prey Selection ◽  
Early Life History ◽  
Generalist Predators ◽  
Life History Variation ◽  
Bioenergetic Model ◽  
Fish Prey ◽  
Lower Growth

The ontogeny of piscivory is an important process during the early life history of many fishes, and why ontogenetic patterns of closely related species vary is unclear. We experimentally evaluated the importance of several factors that can determine the switch to piscivory in two predators with different dietary ontogenies: walleye (Sander vitreus), a specialist piscivore, and yellow perch (Perca flavescens), a dietary generalist. We conducted growth and prey selection experiments across several sizes of both predators using fish, zooplankton, and benthic invertebrates as prey. Walleye exhibited piscivorous feeding behavior throughout all size classes (20–80 mm), whereas yellow perch were generalist predators, showing negative to neutral selection for fish prey and lower growth than walleye when feeding on fish. Walleye foraged more efficiently than yellow perch on all prey types, in part because gape widths of walleye increased more quickly with size. Bioenergetic model simulations showed that walleye grew slower than yellow perch when the proportion of fish was low in diets, but walleye growth was faster than yellow perch on a diet dominated by fish. Feeding behavior, morphology, and life history patterns likely work in combination, allowing walleye to switch to piscivory earlier than yellow perch.

scholarly journals Fish size selection and diet composition of Eurasian otters (Lutra lutra) in salmonid streams: Picky gourmets rather than opportunists?

2019 ◽  
pp. 29 ◽  
Author(s):  
Marcia Sittenthaler ◽  
Lucia Koskoff ◽  
Kurt Pinter ◽  
Ursula Nopp-Mayr ◽  
Rosemarie Parz-Gollner ◽  
...  
Keyword(s):  
Diet Composition ◽  
Multiple Stressors ◽  
Prey Selection ◽  
Temporal Variations ◽  
Salmonid Fish ◽  
Habitat Characteristics ◽  
Lutra Lutra ◽  
Fish Prey ◽  
Dietary Analysis ◽  
Size Selection

Knowledge on predator diet and drivers of prey selection is particularly of interest for an efficient management of predator and prey populations where predators potentially compete with humans for resources. Actual or perceived predation by Eurasian otter (Lutra lutra) on fish stocks generates conflicts in many countries. Recently, conflicts are heating up in riverine habitats, where multiple stressors affect stream fish populations. We combined dietary analysis of otter faeces and prey fish availability in three Austrian streams to assess spatial and seasonal differences in diet composition, the extent of (salmonid) fish consumption and the selection for specific salmonid fish sizes relative to their availability. Otters in upper reaches of temperate salmonid streams occupied a narrow trophic niche. Overall, otters fed predominantly on fish with salmonids dominating diet, both in terms of frequency and ingested biomass measures. Within the category of salmonids, otters selected for specific size classes. Concurrently, otters also displayed an opportunistic feeding behaviour, and seasonally and locally non-fish prey and other fish species than salmonids became key resources. Diet composition and salmonid size selection varied significantly within and between streams, which we relate to spatio-temporal variations of prey community composition and stream-specific habitat characteristics affecting prey vulnerability.

Efficiencies of benthic and pelagic trophic pathways in a subalpine lake

2006 ◽  
Vol 63 (12) ◽  
pp. 2608-2620 ◽  
Author(s):  
M Jake Vander Zanden ◽  
Sudeep Chandra ◽  
Sang-Kyu Park ◽  
Yvonne Vadeboncoeur ◽  
Charles R Goldman
Keyword(s):  
Stable Isotope ◽  
Secondary Production ◽  
Stable Carbon Isotopes ◽  
Prey Selection ◽  
Foraging Efficiency ◽  
Fish Prey ◽  
Algal Production ◽  
Trophic Pathways ◽  
Castle Lake ◽  
Flow Pathways

Although the study of lakes has traditionally focused on pelagic production pathways, recent stable isotope and diet evidence indicates that benthic algal production is an important contributor to fish production. This has led to the suggestion that energy may be more efficiently passed along benthic food chains relative to their pelagic counterparts. To test this idea, we combined stable isotope based assessments of energy flow pathways with estimates of pelagic- and benthic-based primary and secondary production in Castle Lake, California. Approximately 50% of whole-lake primary production and 30% of whole-lake secondary production occurred in benthic habitats. Stable carbon isotopes and dietary data indicated that fish were predominantly supported by benthic (63%) and terrestrial (24%) secondary production. Ecological efficiencies (algal production / invertebrate production) were low in Castle Lake (<3%), though zoobenthic production was more efficiently passed to fish than was zooplankton production. The larger size of benthic prey relative to pelagic prey may affect fish prey selection and foraging efficiency, resulting in differences in ecological efficiency between pelagic and benthic trophic pathways.

Discrimination of fish prey by human listeners using dolphin and porpoise echolocation signals

2011 ◽  
Author(s):  
Caroline M. DeLong ◽  
Irene Kannyo ◽  
Kelly J. Benoit-Bird ◽  
Whitlow W. L. Au
Keyword(s):  
Fish Prey

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 (

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