Further development of the Spalinger-Hobbs mechanistic foraging model for free-ranging moose

1999 ◽  
Vol 77 (10) ◽  
pp. 1505-1512 ◽  
Author(s):  
John Pastor ◽  
Katie Standke ◽  
Keith Farnsworth ◽  
Ron Moen ◽  
Yosef Cohen
Keyword(s):  
Mechanistic Model ◽  
Sequence Length ◽  
Intake Rate ◽  
Frequency Distributions ◽  
Bite Size ◽  
Bite Rate ◽  
Independent Events ◽  
Epilobium Angustifolium ◽  
Free Ranging ◽  
Further Development

Spalinger and Hobbs proposed a mechanistic model of forage intake based on the mutually exclusive actions of biting and chewing. A necessary consequence of this model is that an animal postpones the intake of more food by biting when it is processing food by chewing. In previous work, the Spalinger-Hobbs model successfully predicted short-term intake in controlled experiments. Application of the model to an entire foraging bout requires the following assumptions: (i) biting and chewing are independent events; (ii) there are no periodicities in the length of consecutive bite or chew sequences; (iii) the average bite size is constant; and (iv) the bite rate does not change with the number of bites in the sequence. To test these assumptions, we videotaped entire foraging bouts of two free-ranging moose (Alces alces) feeding on dense swards of Epilobium angustifolium in midsummer. From these videotapes, we measured the time spent biting and chewing, the rates of biting and chewing, the frequency distributions of consecutive bite and chew sequences, and lengths of E. angustifolium shoots above the point of cropping. Plant samples were collected in order to determine bite mass. A total of 1050 bites and chews were analyzed for moose 1 and 1925 bites and chews for moose 2. For both moose, three chewing events occurred, on average, for each bite event. Given this 1:3 bite:chew ratio, the frequency distributions of consecutive bite and chew sequences were as expected from a geometric distribution of independent events. There were no time-series correlations or dominating frequencies in the lengths of bite and chew sequences. These findings fulfill the first three assumptions required to extend the Spalinger-Hobbs model to entire foraging bouts. However, the fourth assumption was not fulfilled, in that time spent per bite increased asymptotically with bite-sequence length. We therefore incorporated the effect of bite-sequence length on bite rate into the Spalinger-Hobbs model. The new model predicts that to simultaneously maximize the marginal intake rate with respect to both bite rate and bite mass, a moose should take single bites most often and bite mass should be approximately 3.6 g. Eighty-two percent of bite sequences were composed of single bites for both moose, and we and others independently observed a bite size of 3.24-3.75 g for free-ranging moose. These observations lend credibility to our modified model.

scholarly journals Winter foraging dynamics of woodland caribou in an artificial landscape

Rangifer ◽  
1996 ◽  
Vol 16 (4) ◽  
pp. 235
Author(s):  
Eric M. Rominger ◽  
Charles T. Robbins
Keyword(s):  
Forest Management ◽  
Intake Rate ◽  
Woodland Caribou ◽  
Bite Size ◽  
Bite Rate ◽  
Factors Influencing ◽  
Winter Foraging

The data suggest that arboreal lichen biomass and/or bite size are primary factors influencing intake rate. Caribou did not increase bite rate to compensate for smaller bite sizes or decreased biomass. Forest management should enhance lichen production to maximize intake rates for woodland caribou.

Effect of species composition and sward structure on the ingestive behaviour of cattle and sheep grazing South African sourveld

1996 ◽  
Vol 127 (2) ◽  
pp. 271-280 ◽  
Author(s):  
P. J. O'Reagain ◽  
B. C. Goetsch ◽  
R. N. Owen-Smith
Keyword(s):  
Species Composition ◽  
Plant Height ◽  
Functional Response ◽  
Major Effect ◽  
Intake Rate ◽  
Sheep Grazing ◽  
Bite Size ◽  
Ingestive Behaviour ◽  
Cattle And Sheep ◽  
Sward Structure

SUMMARYThe effects of species composition and sward structure on the ingestive behaviour of cattle and sheep grazing a mesic, low quality grassland in South Africa were investigated over the 1990–93 grazing seasons. Species composition had a significant (P < 0·05) effect on sheep bite size and on cattle and sheep bite rates but had no effect on dry matter intake rate (IR). Species composition could, however, affect IR over longer grazing periods than those used in the experiment.Sward structure had a major effect on ingestive behaviour. Cattle and sheep bite rates and cattle grazing time, were negatively correlated (P < 0·05) with plant height but positively correlated (P < 0·05) with sward greenness. Bite size and hence IR in cattle and sheep were strongly correlated (P < 0·001) with plant height. Cattle IR increased from 6 to 20g/min over the range of heights encountered and appeared to reach an asymptote at a plant height of 20–25 cm. Sheep IR, expressed per unit of body mass, increased from 0·01 to an asymptote or maximum of 0·13 g/min/kg at plant heights of 10–15 cm. For sheep there was evidence of a non-asymptotic functional response at some sites with IR being maximized at certain sward heights but declining thereafter. This suggests the possible existence of a third, quality dimension to the functional response on these low-quality grasslands.

scholarly journals Canopy structure, ingestive behavior and displacement patterns of beef heifers grazing warm-season pastures

2016 ◽  
Vol 68 (2) ◽  
pp. 457-465 ◽  
Author(s):  
C.L. Glienke ◽  
M.G. Rocha ◽  
L. Pötter ◽  
D. Roso ◽  
D.B. Montagner ◽  
...  
Keyword(s):  
Pearl Millet ◽  
Canopy Structure ◽  
Neutral Detergent Fiber ◽  
Ingestive Behavior ◽  
Displacement Rate ◽  
Compensatory Mechanism ◽  
Intake Rate ◽  
Beef Heifers ◽  
Data Set ◽  
Bite Rate

Analyses in a data set of six experiments (n=436) was performed with the aim of characterizing canopy structure and forage intake patterns of beef heifers grazing on Pearl millet (Pennisetum americanum), Alexandergrass (Urochloa plantaginea) and Coastcross (Cynodon dactylon). Forage and leaf lamina mass were similar among species, 3001.4 and 668.1kg of DM/ha, respectively, while leaf:stem ratio of canopy vertical strata was different. Intake rate (12g DM/minute), bite mass (0.343g DM/bite) and bite rate (36.6bites per minute) were similar in Pearl millet and Alexandergrass. In Pearl millet, neutral detergent fiber content (56.1%) in forage as grazed, grazing time (518.9 minutes/day) and displacement rate (8.8 steps/minute) were lower. Increased grazing time (639 minutes/day) represented the main compensatory mechanism for smaller bite masses (0.234g DM/bite) and reduced intake rates (8.8 grams of DM/minutes) in Coastcross. Bite rate variations happened as a response to constraints imposed by canopy structure. Surface utilization on Alexandergrass and Coastcross was increased by greater number of feeding stations visited and displacement rate. Ingestive behavior components of beef heifers are affected by differences in the canopy structure of Pearl millet, Alexandergrass and Coastcross.

Integrating behavior and cardiovascular responses: posture and locomotion. I. Static analysis

1993 ◽  
Vol 265 (6) ◽  
pp. R1458-R1468 ◽  
Author(s):  
O. A. Smith ◽  
C. A. Astley ◽  
F. A. Spelman ◽  
E. V. Golanov ◽  
V. G. Chalyan ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Blood Flow ◽  
Computer Control ◽  
Cardiovascular Responses ◽  
Papio Hamadryas ◽  
Code Generator ◽  
Frequency Distributions ◽  
Arterial Blood ◽  
Free Ranging

Heart rate, arterial blood pressure, and renal and mesenteric or femoral blood flow were telemetered from 11 Papio hamadryas in an untethered free-ranging situation. The animals' behavior was recorded on videotape, and the cardiovascular (CV) data were recorded on the audio channels of the tape. The behavior was coded, and the codes were linked to the CV data via a time-code generator and computer control. The CV data were digitized into 1-s intervals, and the static relations between CV measures and the postures/locomotions (P/Ls) associated with the behavior were analyzed. The total frequency distributions for heart rate, blood pressure, and renal conductance approximated Gaussian distributions, whereas femoral conductance was positively skewed. The distribution for renal conductance suggested that during normal waking conditions the kidney is not maximally dilated and may increase or decrease its blood flow. All distributions were highly influenced by the Sit category, which occupied 80% of the total time. The CV measures for all P/Ls had wide ranges, and the CV values associated with each P/L overlapped those for the other P/Ls. The heart rate and renal conductance associated with the various P/Ls showed the largest deviations from the grand means and therefore contributed the most to the ability to discriminate one P/L from another. Blood pressure varied little from one P/L to another. The patterns of CV variables served to distinguish particular P/Ls very effectively. The frequency distributions were separated best when they were parceled on the basis of the intensity of behavior associated with a particular P/L. These variations in intensity were the major cause of the overlaps in the frequency distributions associated with P/Ls.

Investigation of alternative baits for rabbit control, and the examination of the distribution and longevity of 1080 in One-shot oats

2003 ◽  
Vol 30 (6) ◽  
pp. 573 ◽  
Author(s):  
Laurie E. Twigg ◽  
Tim J. Lowe ◽  
Winifred E. Kirkpatrick ◽  
Gary R. Martin
Keyword(s):  
Active Ingredient ◽  
Vacuum Impregnation ◽  
Uniform Size ◽  
Control Programs ◽  
Grain Products ◽  
Individual Grains ◽  
Free Ranging ◽  
The Impact ◽  
Further Development ◽  
Nominal Amount

The use of 1080-poisoned oats in rabbit-control programs has become less effective in some areas of Australia. Consequently, factors likely to influence the effectiveness of this bait, and alternative grain products for rabbit control, were investigated. Vacuum impregnation rates with 1080 (sodium monofluoroacetate) for malted and unmalted barley were such that all barley products tested could be used as bait material in conventional rabbit-control programs where individual grains need to contain ~0.02–0.04 mg of 1080. In contrast, only the impregnation rates for malted barley (3.2 mg per grain) showed sufficient promise that this product could be considered for further development for use in 'One-shot' rabbit-control programs (poison grains nominally need to contain 4.5 mg 1080). Compared with oats, non-toxic malted and unmalted barley were equally acceptable food items to free-ranging rabbits. The addition of salt (NaCl, 0.9%) did not enhance the consumption of bait (oats and malted barley).1080 was not uniformly distributed throughout the poisoned One-shot oats, with 80% of the active ingredient in the husk, and 20% in the kernel. The size of oat also influenced impregnation rates, with the larger grains containing more 1080. Dehusking of the oats by rabbits (i.e. only the kernel was consumed) occurred in ~84% of cases examined (n = 31 food stations). As little as 6 mm of rainfall resulted in the total loss of detectable amounts of 1080 in One-shot oats collected over 41 days from a standard bait trail laid on sandy soil during summer. The impact of the above on rabbit-control programs could be potentially overcome (partially or wholly) by: the development and inclusion of barley products as bait, the alternation of conventional and One-shot baiting techniques in control programs, the responsible inclusion of a chronic poison (e.g. anticoagulant, pindone) in baiting programs, and ensuring that all poison grains in any bait are of uniform size and contain as close as possible to the nominal amount of active ingredient.

Mechanics of browsing in dense food patches: effects of plant and animal morphology on intake rate

1992 ◽  
Vol 70 (9) ◽  
pp. 1743-1752 ◽  
Author(s):  
Lisa A. Shipley ◽  
Donald E. Spalinger
Keyword(s):  
Functional Response ◽  
Rangifer Tarandus ◽  
Asymptotic Relation ◽  
Acer Rubrum ◽  
Neutral Detergent Fiber ◽  
Intake Rate ◽  
Red Maple ◽  
Bite Size ◽  
Snowshoe Hares ◽  
Asymptotic Function

There appear to be two dominant forms of the functional response of vertebrate herbivores, corresponding to animals foraging in spatially concentrated or spatially dispersed food patches. We examine the factors contributing to the functional response of herbivores feeding on spatially concentrated browses. Specifically, we tested the hypothesis that the instantaneous intake rate of four boreal browsers (moose, Alces alces, woodland caribou, Rangifer tarandus caribou, white-tailed deer, Odocoileus virginianus, and snowshoe hares, Lepus americanus) feeding on red maple (Acer rubrum) browse is an asymptotic function of the size of bite obtainable by the herbivore. Based on this functional response model, we also hypothesized that (i) cropping rate of the herbivores would decline curvilinearly with bite size, (ii) intake rate would decline with increasing fibrousness (measured, as the neutral detergent fiber of the foods consumed), and (iii) maximum intake rate would scale as the 2/3 power of herbivore body mass (BM). Intake rates of all animals increased 2- to 10-fold with increasing bite size of stems and leaves, and conformed to the hypothesized asymptotic relation. Similarly, cropping rate declined curvilinearly with increasing bite size, and intake rate declined with increasing fibrousness of foods consumed. Maximum intake rate scaled with BM0.76, not significantly different from the hypothesized exponent of 0.67. These data support the hypothesis that bite size affects intake rate by controlling the ratio of cropping and chewing, and that the asymptotic intake rate of herbivores is related to the food processing capability of the mouth.

Scale Composition and Item Analysis of the Communication Profile for the Hearing Impaired

1986 ◽  
Vol 29 (4) ◽  
pp. 515-535 ◽  
Author(s):  
Marilyn E. Demorest ◽  
Sue Ann Erdman
Keyword(s):  
Medical Center ◽  
Item Analysis ◽  
Hearing Impaired ◽  
Walter Reed Army Medical ◽  
Final Phase ◽  
Self Assessment ◽  
Communication Performance ◽  
Frequency Distributions ◽  
Further Development ◽  
Scale Composition

The Communication Profile for the Hearing Impaired (CPHI) is a self-assessment inventory that provides 25 scores describing the Communication Performance, Communication Environment, Communication Strategies, and Personal Adjustment of hearing-impaired adults (Demorest & Erdman, 1986). Description of the content and measurement objective for each scale is given and an analysis of the psychometric properties of the 145 items in the CPHI is presented. Results are based on a sample of 433 active-duty military personnel tested at Walter Reed Army Medical Center during the final phase of CPHI development. Included are frequency distributions, descriptive statistics, item-total correlations, and factor structure of the items within each scale and across scales within each of the areas assessed by the CPHI. Applications of these data in clinical interpretation, construct validation, and further development of the CPHI scales are discussed.

scholarly journals Forage intake processes by goats on a massai grass pasture with different sward heights

2016 ◽  
Vol 37 (6) ◽  
pp. 4339
Author(s):  
Marcônio Martins Rodrigues ◽  
Maria Elizabete Oliveira ◽  
Tânia Maria Leal ◽  
Raniel Lustosa Moura ◽  
Daniel Louçana da Costa Araújo ◽  
...  
Keyword(s):  
Crude Protein ◽  
Leaf Blade ◽  
Intake Rate ◽  
Crude Protein Content ◽  
Intake Process ◽  
Bite Rate ◽  
Sward Height ◽  
Morphological Composition ◽  
Reduced Crude Protein ◽  
Forage Intake

The objective of this study was to evaluate the forage-intake process of goats feeding on Massai grass pastures with different heights (40, 50, 60, and 70 cm). The experimental design was completely randomized, with treatments corresponding to four sward heights with two replicates over time and space. Collected data were related to the forage-intake process and the chemical and morphological composition of the pasture. Grazing trials (45 min) were performed with four Anglo-Nubian crossbred goats. Total forage mass intake, bite mass, and intake rate were expressed in relation to animal weight. Pasture density, forage mass, and leaf blade increased as forage height increased. The chemical composition of forage at the evaluated heights was similar, except for reduced crude protein content at 70-cm height. Bite rate, intake rate, and time per bite had a quadratic relationship with increasing sward height. The greatest intake rate was observed at 54.7 cm of height, with 0.136 g DM min-1 kg-1 LW. Bite rate exhibited a linear and positive correlation with increase in intake. At the 50-cm height, goats harvested a mass of 3.65 g DM bite-1 kg-1 LW, when they performed 34.5 bites per minute. Adult goats had a greater forage intake on 50-cm high Massai grass pastures because they could obtain a greater bite mass in a shorter time per bite.

scholarly journals On the verge of life: Distribution of nucleotide sequences in viral RNAs

2021 ◽  
Author(s):  
Mykola Husev ◽  
Andrij Rovenchak
Keyword(s):  
Rna Viruses ◽  
Nucleotide Sequences ◽  
Sequence Length ◽  
Life Distribution ◽  
Frequency Distributions ◽  
Classification Of Diseases ◽  
Negative Hypergeometric Distribution ◽  
Human Coronaviruses ◽  
Best Fit

Abstract The aim of the study is to analyze viruses using parameters obtained from distributions of nucleotide sequences in the viral RNA. Seeking for the input data homogeneity, we analyze single-stranded RNA viruses only. Two approaches are used to obtain the nucleotide sequences; In the first one, chunks of equal length (four nucleotides) are considered. In the second approach, the whole RNA genome is divided into parts by adenine or the most frequent nucleotide as a "space''. Rank--frequency distributions are studied in both cases. The defined nucleotide sequences are signs comparable to a certain extent to syllables or words as seen from the nature of their rank--frequency distributions. Within the first approach, the P\'olya and the negative hypergeometric distribution yield the best fit. For the distributions obtained within the second approach, we have calculated a set of parameters, including entropy, mean sequence length, and its dispersion. The calculated parameters became the basis for the classification of viruses. We observed that proximity of viruses on planes spanned on various pairs of parameters corresponds to related species. In certain cases, such a proximity is observed for unrelated species as well calling thus for the expansion of the set of parameters used in the classification. We also observed that the fourth most frequent nucleotide sequences obtained within the second approach are of different nature in case of human coronaviruses (different nucleotides for MERS, SARS-CoV, and SARS-CoV-2 versus identical nucleotides for four other coronaviruses). We expect that our findings will be useful as a supplementary tool in the classification of diseases caused by RNA viruses with respect to severity and contagiousness.

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