Electroreception and the feeding behaviour of platypus ( Ornithorhynchus anatinus : Monotremata: Mammalia)

1995 ◽  
Vol 347 (1322) ◽  
pp. 359-381 ◽  
Keyword(s):  
Feeding Behaviour ◽  
Electrical Pulse ◽  
Feeding Strategies ◽  
Directional Sensitivity ◽  
Electrical Noise ◽  
Faraday Cage ◽  
Electrical Fields ◽  
Ornithorhynchus Anatinus ◽  
First Time ◽  
Freshwater River

It has previously been shown that platypus are sensitive to small electrical fields. It was predicted that platypus use their electrosensitivity to locate the source of foodstuffs on the bottom of the freshwater river systems in which they live, because the platypus are nocturnal, and close their eyes, ears and nostrils while underwater. In this paper we demonstrate for the first time that platypus are indeed sensitive to electrical waveforms that imitate the electromyogenic potential’s of fleeing prey, and following stimulation show interest in area surrounding the electrodes. We also show that platypus respond with a reflex after stimulation with a square wave, and show that this reflex is directionally tuned to the origin of the electrical pulse, with a preferential sensitivity axis 40 times more sensitive than non-preferred axes. The strong directional sensitivity explains previous discrepancies in the lowest threshold for platypus electroreception, which we find to be 50 μV cm -1 . Platypus are also sensitive to galvanic fields. We present the data in the light of standardized feeding strategies of the platypus, and discuss the integration of the findings into these feeding strategies. We surrounded our platypus enclosure with a Faraday cage, thereby eliminating excess electrical noise, a suggested new addition to the husbandry regime of platypus.

The influence of feeding strategies on the attendance of cows to an automatic milking system, and their effects on lying and feeding behaviour

1996 ◽  
Vol 1996 ◽  
pp. 78-78
Author(s):  
N.B. Prescott ◽  
T.T.F. Mottram ◽  
A.J.F. Webster
Keyword(s):  
Feeding Behaviour ◽  
The Other ◽  
Feeding Strategies ◽  
Alternative Design ◽  
Milk Cows ◽  
Automatic Milking System ◽  
Automatic Milking ◽  
Effect Of Feeding

An automatic milking system (AMS) has the potential to milk cows when the cow chooses. However cows must attend the system at an appropriate frequency. The provision of food in the AMS is a robust, way of luring cows into the system. The system can be arranged such that the cows have to visit the AMS to access food in the exit area the other side. Here they can be fed forage or concentrate. It has been shown that feeding cows forage as a lure can result in modified forage feeding behaviour, and this may be to the detriment of the cows (Winter, 1993, Ketelaar-de-Lauwere, 1992). Feeding concentrate in the exit area may be an alternative design if the level of attendance generated is high enough. Cows can also be fed concentrate in the milking stall of the AMS. The aim of this experiment was to compare die effects of feeding forage or concentrate in the exit area and the effect of feeding or not feeding concentrate in the milking stall on attendances, and lying and feeding behaviour.

Tunneling and Percolation Behavior in Granular Metals

1990 ◽  
Vol 195 ◽  
Author(s):  
I. Balberg ◽  
N. Wagner ◽  
Y. Goldstein ◽  
S.Z. Weisz
Keyword(s):  
Computer Simulation ◽  
Critical Behavior ◽  
Quantum Mechanical ◽  
Electrical Noise ◽  
Quantum Mechanical Tunneling ◽  
Percolation Process ◽  
Percolation Behavior ◽  
Metallic Grains ◽  
First Time ◽  
Special Case

ABSTRACTThe nature of the percolation process in granular metals is examined for the first time by a computer simulation of a system of metallic grains embedded in an insulating matrix. Assuming that the intergrain conduction is due to quantum mechanical tunneling it is found that a percolation-like critical behavior of the conductivity is obtained, but that a percolation universal behavior will be found only in a very special case. In contrast, the behavior of the electrical noise does not deviate substantially from the universal one. Comparison of these results with recent experimental observations suggests that in the metallic range, both transport properties are controlled by the continuous metallic network rather than by intergrain tunnelin.. We propose that the metallic network resembles the previously studied system of ‘inverted random voids’.

Aspects of Lactation in the Platypus, Ornithorhynchus anatinus (Monotremata), in Waters of Eastern New South Wales.

1983 ◽  
Vol 31 (6) ◽  
pp. 881 ◽  
Author(s):  
TR Grant ◽  
M Griffiths ◽  
RMC Leckie
Keyword(s):  
New South ◽  
New South Wales ◽  
Young Leave ◽  
South Wales ◽  
Ornithorhynchus Anatinus ◽  
Significant Difference ◽  
Lactating Females ◽  
One Year ◽  
The One ◽  
First Time

Female platypuses captured in waters of eastern New South Wales were found to be lactating between the months of October and March. Lactating females were most numerous in December, accounting for 64% of females captured. Non-lactating females were taken in all months, indicating that not all females breed successfully every year. There was no significant difference between the fatty acid complement of milk taken from a platypus lactating very late in the season and those of others sampled in December at the peak of the lactation season. Some evidence exists that females do not become reproductive until at least their second year of life. Some females were found lactating in consecutive years, and others lactated one year and not in the one following. Animals of over 9 years of age are known to breed. Most juveniles were captured in February, March and April, and it is suggested that the young leave the breeding burrows for the first time in late January through to March, and become independent from their mothers, who are ceasing lactation at that time.

scholarly journals Diurnal feeding strategies of the Ferruginous Duck (Aythya nyroca) in Lake Tonga (Northeastern Algeria)

2019 ◽  
Vol 27 (1) ◽  
pp. 85-98 ◽  
Author(s):  
Khalil Draidi ◽  
Badis Bakhouche ◽  
Naouel Lahlah ◽  
Imed Djemadi ◽  
Mourad Bensouilah
Keyword(s):  
Feeding Behaviour ◽  
Foraging Behaviour ◽  
Time Budget ◽  
Search Time ◽  
Environmental Parameters ◽  
Feeding Strategies ◽  
A Minor ◽  
Northeastern Algeria ◽  
Foraging Time ◽  
Minor Activity

Abstract Although the Ferruginous Duck (Aythya nyroca) has thoroughly been studied, the foraging behaviour of this species is still not completely known. In the present paper we studied the diurnal feeding behaviour of ducks. We monitored the annual cycle of birds through two fieldtrips per month. The instantaneous behaviour of birds was recorded in regular 30-minute intervals from 7 a.m. to 4:30 p.m., amounting a total of 456 observation hours. Food searching activity corresponds to a quarter of the total diurnal time budget of the Ferruginous Duck. Foraging behaviour was classified into five categories dominated by the “diving”, which is almost 45.61% of the total search time. Foraging activities at the water surface considered to be secondary activities, including feeding by “bill”, “neck and head”, and “beak and head” in a rate of 19.86%, 14.53%, and 13.98%, respectively. The “toggle” remains a minor activity and represents only 5.99% of foraging time. The feeding behaviour of this species correlated to several environmental parameters (rainfall, temperature and wind velocity), and linked to the group size of ducks visiting the lake. Regarding the food intensity, our results show the highest values for “bill and head” behaviour. “Diving” has the longest feeding interval (16.16±14.1 minutes), while foraging by “bill” has the shortest (0.69 ± 0.48 minutes).

All post- Cambrian ichnospecies of Psammichnites Torell, 1870 belong to Olivellites Fenton and Fenton, 1937a

2021 ◽  
pp. SP522-2021-102
Author(s):  
Pablo J. Pazos ◽  
Carolina Gutiérrez
Keyword(s):  
Feeding Behavior ◽  
Tidal Flat ◽  
Host Rock ◽  
Mass Extinction ◽  
Feeding Behaviour ◽  
Late Ordovician ◽  
Feeding Strategies ◽  
Bathymetric Range ◽  
The Usa

AbstractThe ichnogenus Psammichnites herein restricted to Psammichnites gigas is based on comparison of morphology, feeding behaviour, contrast between the burrows and the host rock and possible producers. The record of siphonal activity as a “snorkel device” is discussed. The diagnosis of the ichnogenus Olivellites now is amended and includes all the records of Psammichnites in the post-Cambrian. Olivellites is now documented in successions other than the classical tidal flat deposits facies of the Carboniferous of the USA. We propose that the producer of Olivellites was an animal with capacity for displacement to different shallow infaunal levels for different feeding strategies. An interpretation of detritus feeding behavior with sediment displacement (pasichnia) is favoured here. The producer of Olivellites was likely to have been a bivalved mollusc that evolved after the Late Ordovician mass extinction. It was euryhaline and lived in a broad bathymetric range, and is recorded in temperate to glacially related successions. The material of Olivellites implexus from western Argentina is the youngest record of the ichnogegenus from Western Gondwana.

Ocurrence and independent evolution of bilateral ear asymmetry in owls and implications on owl taxonomy

1977 ◽  
Vol 280 (973) ◽  
pp. 375-408 ◽  
Keyword(s):  
Selection Pressure ◽  
Food Selection ◽  
Spectral Composition ◽  
Directional Sensitivity ◽  
Bilateral Asymmetry ◽  
High Frequencies ◽  
Vertical Error ◽  
Localization Ability ◽  
First Time ◽  
Vertical Localization

On the basis of the literature and my own examination of living and/or dead but fresh owls of 16 species, bilateral asymmetry of external ears in owls is surveyed and ear structure briefly described. Consideration of the probability of origin of various structural similarities and dissimilarities in the ear leads to the conclusion that ear asymmetry has evolved independently in at least five lines, represented by the respective genera (1) Tyto , (2) Phodilus , (3) Bubo , Ciccaba , Strix , (4) Rhinoptynx , Asio , Pseudoscops , and (5) Aegolius . Bubo , Ciccaba , and Strix probably represent more than one line of origin of ear asymmetry. Available evidence suggests that bilateral ear asymmetry in owls serves to make the vertical directional sensitivity patterns different between the two ears for high frequencies, thus making possible vertical localization based on binaural comparison of intensity and spectral composition of sound. When an owl localizes prey by hearing, the direction of the source usually forms a shallow angle with the ground. Therefore, a certain angle of error usually converts into a longer distance along the ground for a vertical error than for a horizontal error. This is a crucial factor that calls for good vertical localization ability of owls which rely on hearing for localization of food. Selection pressure for improvement of the ability of vertical localization of sound is believed to lie behind the evolution of all types of bilateral ear asymmetry in owls. On the basis of comparative ear structure the current subdivision of family Strigidae into subfamily Buboninae and Striginae is rejected. The external ears of Rhinoptynx and Pseudoscops are described for the first time and shown to be very similar to those of Asio otus , demonstrating affinity between these three genera.

scholarly journals The Joint Effect of pH Gradient and Glucose Feeding on the Growth Kinetics of Lactococcus lactis CECT 539 in Glucose-Limited Fed-Batch Cultures

2019 ◽  
Vol 68 (2) ◽  
pp. 269-280
Author(s):  
MÓNICA COSTAS MALVIDO ◽  
ELISA ALONSO GONZÁLEZ ◽  
RICARDO J. BENDAÑA JÁCOME ◽  
NELSON PÉREZ GUERRA
Keyword(s):  
Lactococcus Lactis ◽  
Viable Cell ◽  
Product Formation ◽  
Ph Gradient ◽  
Feeding Strategies ◽  
Fed Batch ◽  
Batch Cultures ◽  
Cell Counts ◽  
First Time ◽  
Kinetics Of

Two glucose-limited realkalized fed-batch cultures of Lactococcus lactis CECT 539 were carried out in a diluted whey medium (DW) using two different feeding media. The cultures were fed a mixture of a 400 g/l concentrated lactose and a concentrated mussel processing waste (CMPW, 101.72 g glucose/l) medium (fermentation I) or a CMPW medium supplemented with glucose and KH2PO4 up to concentrations of 400 g glucose/l and 3.21 g total phosphorus/l, respectively (fermentation II). For an accurate description and a better understanding of the kinetics of both cultures, the growth and product formation by L. lactis CECT 539 were both modelled, for the first time, as a function of the amounts of glucose (G) added and the pH gradient (VpH) generated in every realkalization and feeding cycle, by using an empirical polynomial model. With this modeling procedure, the kinetics of biomass, viable cell counts, nisin, lactic acid, acetic acid and butane-2,3-diol production in both cultures were successfully described (R2 values > 0.970) and interpreted for the first time. In addition, the optimum VpH and G values for each product were accurately calculated in the two realkalized fed-batch cultures. This approach appears to be useful for designing feeding strategies to enhance the productions of biomass, bacteriocin, and metabolites by the nisin-producing strain in wastes from the food industry.

scholarly journals Preliminary trophic analysis of leaf-mining Nepticulidae: pronounced feeding strategies in Middle and South America?

Biologija ◽  
2017 ◽  
Vol 62 (4) ◽  
Author(s):  
Andrius Remeikis ◽  
Arūnas Diškus ◽  
Jonas R. Stonis
Keyword(s):  
South America ◽  
Host Plant ◽  
Trophic Relationships ◽  
Feeding Strategies ◽  
Current Analysis ◽  
Paper Briefly ◽  
Leaf Mining ◽  
The Caribbean ◽  
First Time ◽  
Trophic Analysis

The paper briefly analyzes trophic relationships of Nepticulidae occurring in Middle and South America (the Neotropical and Ando-Patagonian regions) for the  first time. The  results show some peculiar features, including unexpectedly large percentage of taxa trophically associated with Asterales (Asteraceae) and Lamiales plants. However, because of insufficient sampling in most regions of the Caribbean and Middle and South America as well as the  fact that only 50% of analyzed taxa are known in host-plant records, the  results of current analysis should be treated as preliminary.

scholarly journals Comparative study of feeding behaviour of five Mugilidae species juveniles from two estuarine systems in the North Aegean Sea

2016 ◽  
Vol 98 (2) ◽  
pp. 283-297 ◽  
Author(s):  
Ioanna Salvarina ◽  
Emmanuil Koutrakis ◽  
Ioannis Leonardos
Keyword(s):  
Feeding Behaviour ◽  
Juvenile Fish ◽  
General Pattern ◽  
Aegean Sea ◽  
Trophic Levels ◽  
Feeding Strategies ◽  
Estuarine System ◽  
North Aegean ◽  
Estuarine Systems ◽  
North Aegean Sea

Food is an important factor for the survival of juvenile fish. Knowledge of the diet of co-existing species helps clarify their relationships with each other. A number of Mugilidae species are known to co-exist in estuarine systems, raising the question of whether they compete for food resources. The feeding behaviours of five juvenile Mugilidae species were studied in the estuaries of Strymonikos (North Aegean Sea) using stomach content analysis. It was found that the species Chelon labrosus, Liza saliens and Mugil cephalus presented high feeding activity during summer and autumn and L. ramada and L. aurata during winter and spring. The diet overlap between the species was generally moderate to low and the pair L. saliens – M. cephalus exhibited the highest overlap in Richios estuarine system. The species do not appear to compete for common resources, probably because there is not always a spatiotemporal overlap, enough food is available or they exploit different resources. Four out of the five species exhibited similar patterns of feeding strategies with varying levels of specialization at an individual level and a rather generalized pattern at the population level. This more generalized feeding strategy may permit them to co-exist. Only M. cephalus showed a more specialized feeding behaviour, with a strong preference for microalgae. The absence of a general pattern for the trophic levels according to seasons, sizes or locations, also imply the opportunistic character of the species. Both season and fish size influenced the variation in the diet composition.

Revision of the Australian Ascidae (Acarina : Mesostigmata)

1998 ◽  
Vol 12 (1) ◽  
pp. 1 ◽  
Author(s):  
R. B. Halliday ◽  
D. E. Walter ◽  
E. E. Lindquist
Keyword(s):  
New Species ◽  
Feeding Behaviour ◽  
Australian Species ◽  
The World ◽  
First Time

Ascid mites are an important component of the predatory meiofauna in soil, onvegetation, and in association with other animals, yet the Australian fauna isalmost unknown. At least 15 genera of ascid mites occur in Australia, of which14 genera and 26 species are treated in this paper. Four of these genera(Gamasellodes, Hoploseius,Platyseius,Xenoseius) are hererecorded from Australia for the first time. Six new species are described[Antennoseius(Antennoseius)lobochelus, sp.nov., Arctoseius memnon, sp. nov.,Gamasellodes plaire, sp. nov.,Platyseius cupensis, sp.nov., Xenoseius elizae, sp. nov., andZerconopsis pristis, sp. nov.], and six otherspecies are reported from Australia for the first time[Arctoseius semiscissus(Berlese),Gamasellodes rectiventris Lindquist,Proctolaelaps aurora(Vitzthum),Proctolaelaps bickleyi(Bram), Proctolaelaps lobatus De Leon, andProtogamasellus massula (Athias-Henriot)].Proctolaelaps nesbitti (Womersley) is removed fromsynonymy with P. pygmaeus (MÜller). Lectotypes aredesignated for Proctolaelaps antennatusKarg andP. australis Stone.P. antennatushas wrongly been recorded from Australia, and is known only from New Zealand.The first observations of feeding behaviour of mites in the generaIphidozercon, Xenoseius andZerconopsis confirm that nematophagy is prevalent amongsoil Ascidae. Keys to the world genera and Australian species areprovided.Protogamasellopsis Evans and Purvis istransferred to the Rhodacaridae, TangarorellusLuxton toan unspecified family in the Rhodacaroidea, andLindquistoseius Genis, Loots & Ryke to theOlogamasidae. OrolaelapsDeLeon is removed from synonymywith Melichares Hering. The following new synonymies areproposed: Arctoseius bicuspidatus Willmann, 1949 andArctoseius limburgensis Nesbitt, 1954 =Arctoseius semiscissus (Berlese, 1892);Cheiroseius (Posttrematus) Karg,1981 = EpiseiusHull,1918;Iphidozercon californicus Chant,1963,Leioseius (Arctoseius)elegans Bernhard, 1963 andIphidozercon variolatus Ishikawa, 1969=Iphidozercon corticalisEvans, 1958;Garmania longipilis Chant, 1958=Proctolaelaps aurora(Vitzthum, 1925);Proctolaelaps lewisi Garman & McGregor, 1956= P. utahensis Chant, 1958;Lasioseius convivavar.laevisternus Berlese, 1916a =Proctolaelaps pygmaeus(MÜller,1859);Neojordensia lativentris Karg, 1982 =Africoseius areolatus Krantz, 1962.

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