INDIVIDUAL VARIATION IN THE ACOUSTIC BEHAVIOUR OF THE ADULT MALE LEOPARD SEAL, HYDRURGA LEPTONYX

Behaviour ◽  
2002 ◽  
Vol 139 (10) ◽  
pp. 1267-1286 ◽  
Author(s):  
Douglas Cato ◽  
Tracey Rogers

AbstractVocalisations and vocalising bouts of adult male leopard seals recorded from the Prydz Bay region, East Antarctica, were compared to determine whether they showed individual variability. There were distinct individual patterns in the sequence of vocalisations within vocalising bouts. A sequence could be reliably ascribed to a particular individual with a high degree (83%) of certainty. Such sequences may carry information about the identity of the caller. Acoustic characteristics of the two most commonly used vocalisations, the high and low double trills, showed weak within individual variation. Although differences were observed among individuals in the high double trill few were observed in the low double trill consequently the low double trills of some individuals could not be reliably ascribed to any particular seal. For many species, individual variation occurs in acoustic characteristics of specific vocalisations rather than in the sequence in which the vocalisations are produced. The acoustic displays of solitary species such as the leopard seal, are constrained by the difficulties of detecting and recognising the signal at a distance. Vocalisation sequences may be less adversely affected by signal degradation and so could be effective for communicating information over distance. It has been suggested that individual acoustic variation is found primarily in gregarious species however findings from the current study suggest that solitary animals using long-range underwater acoustic displays may convey individual variability in their vocalising sequence patterns.

2021 ◽  
Vol 8 (2) ◽  
Author(s):  
Denis Goncharov ◽  
Richard Policht ◽  
Lucie Hambálková ◽  
Viktor Salovarov ◽  
Vlastimil Hart

Based on their phylogenetic position, Nearctic ground squirrels are closest relatives to the long-tailed ground squirrel Urocitellus undulates even though it has Palaearctic distribution. We aimed to investigate the variability of alarm calls of the long-tailed ground squirrel to test the individual variation in alarm calls. This species is known to produce two types of alarm calls: whistle alarms and wideband calls. Although ground squirrels are a model group for the study of vocal individuality, this phenomenon has not yet been studied in a species producing two such completely different types of alarms. Most of ground squirrel species produce either whistle or wideband alarms and this species represents a unique model for testing the degree of individual variability depending on completely different acoustic structures. We analysed 269 whistle alarms produced by 13 individuals and 591 wideband alarms from 25 individuals at the western part of Lake Baikal. A discriminant function analysis (DFA) assigned 93.5% (88.9%, cross-validated result) of whistle alarms to the correct individual and 91.4% (84%) of wideband alarms. This is the first evidence of individual variation in wideband alarms compared with whistle alarms and occurrence of vocal individuality in two warning signals of a completely different acoustic structure produced by a ground squirrel.


2019 ◽  
Vol 42 ◽  
Author(s):  
Emily F. Wissel ◽  
Leigh K. Smith

Abstract The target article suggests inter-individual variability is a weakness of microbiota-gut-brain (MGB) research, but we discuss why it is actually a strength. We comment on how accounting for individual differences can help researchers systematically understand the observed variance in microbiota composition, interpret null findings, and potentially improve the efficacy of therapeutic treatments in future clinical microbiome research.


1986 ◽  
Vol 56 (03) ◽  
pp. 371-375 ◽  
Author(s):  
Peretz Weiss ◽  
Hillel Halkin ◽  
Shlomo Almog

SummaryWithin-individual variation over time in the clearance (Cl) and effect (PT%) of warfarin, was measured in 25 inpatients (group I) studied after standard single or individualized split loading doses and 1-3 times (n = 16) 8-16 weeks later during maintenance. Mean Cl (2.5 α 0.9 ml/min) was similar in both phases but significant changes occurred in 6/16 patients, exceeding those expected from within-individual variation alone (defined by its 95% tolerance limits -24% to +62%). Initial PT% (21 α 5) was unaffected by dosing schedule, total or free plasma warfarin, varying between patients by only 18-24%. Mean initial and maintenance dose-PT% ratios (8.2 mg/d: 21% and 4.1 mg/d: 40%) were similar but significant changes in sensitivity to warfarin occurred in 4/16 patients. In group I and 64 other outpatients on maintenance therapy, between-individual variability was 36-52% for Cl and 49-56% for effect. PT% correlated best (r = 0.56) with free and total plasma warfarin but poorly with dose (r = 0.29), with only 30% of PT% variance explained at best, due to high between patient variability.Warfarin dose prediction whether based on extrapolation from initial effects to the maintenance phase, or on iterative methods not allowing for between- or within-patient variation in warfarin clearance or effect which may occur independently over time, have not improved on empirical therapy. This, due to the elements of biological variability as well as the intricacy of the warfarin - prothrombin complex interaction not captured by any kinetic-dynamic model used for prediction to date.


2019 ◽  
Author(s):  
Vera Weisbecker ◽  
Thomas Guillerme ◽  
Cruise Speck ◽  
Emma Sherratt ◽  
Hyab Mehari Abraha ◽  
...  

AbstractBackgroundWithin-species skull shape variation of marsupial mammals is widely considered low and strongly size-dependent (allometric), possibly due to developmental constraints arising from the altricial birth of marsupials. However, species whose skulls are impacted by strong muscular stresses – particularly those produced through mastication of tough food items – may not display such intrinsic patterns very clearly because of the known plastic response of bone to muscle activity of the individual. In such cases, shape variation should not be dominated by allometry; ordination of shape in a geometric morphometric context through principal component analysis (PCA) should reveal main variation in areas under masticatory stress (incisor region/zygomatic arches/mandibular ramus); but this main variation should emerge from high individual variability and thus have low eigenvalues.ResultsWe assessed the evidence for high individual variation through 3D geometric morphometric shape analysis of crania and mandibles of thre species of grazing-specialized wombats, whose diet of tough grasses puts considerable strain on their masticatory system. As expected, we found little allometry and low Principal Component 1 (PC1) eigenvalues within crania and mandibles of all three species. Also as expected, the main variation was in the muzzle, zygomatic arches, and masticatory muscle attachments of the mandibular ramus. We then implemented a new test to ask if the landmark variation reflected on PC1 was reflected in individuals with opposite PC1 scores and with opposite shapes in Procrustes space. This showed that correspondence between individual and ordinated shape variation was limited, indicating high levels of individual variability in the masticatory apparatus.DiscussionOur results are inconsistent with hypotheses that skull shape variation within marsupial species reflects a constraint pattern. Rather, they support suggestions that individual plasticity can be an important determinant of within-species shape variation in marsupials (and possibly other mammals) with high masticatory stresses, making it difficult to understand the degree to which intrinsic constraint act on shape variation at the within-species level. We conclude that studies that link micro- and macroevolutionary patterns of shape variation might benefit from a focus on species with low-impact mastication, such as carnivorous or frugivorous species.


2016 ◽  
pp. 24 ◽  
Author(s):  
Malini Suchak ◽  
Michael Piombino ◽  
Kalina Bracco

Colony housing of cats allows shelters to maximize the number of cats housed in limited space. Most research on colony-housed cats examines stress in relation to group size or enclosure size.  While this is important for evaluating welfare, it is equally important to understand how cats are interacting socially in these colonies. We observed 259 adult cats housed in groups of two to eight individuals. Scan samples were used to assess how frequently individual cats were in close proximity to other cats. These data were used to measure individual differences in sociability and patterns of proximity to certain partners. We used information about the past history of the cat, which was collected upon admission to the shelter to identify predictors of time spent in proximity. There was a high degree of inter-individual variability in sociability. Strays tended to spend less time in proximity to other cats, and this effect was most pronounced in females.However, none of the information collected upon admission predicted patterns of proximity to certain partners, or which cats spent time in association witheach other. Future studies should explore the implications of differences in sociability by associating observations of social behavior and stress behaviors.


Nutrients ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 2026
Author(s):  
Karen Elizabeth Charlton ◽  
Aletta Elisabeth Schutte ◽  
Leanda Wepener ◽  
Barbara Corso ◽  
Paul Kowal ◽  
...  

Given a global focus on salt reduction efforts to reduce cardiovascular risk, it is important to obtain accurate measures of salt intake on a population level. This study determined firstly whether adjustment for intra-individual variation in urinary sodium (Na) excretion using three repeated 24 h collections affects daily estimates and whether the use of repeated spot urine samples results in better prediction of 24 h Na compared to a single collection. Twenty three community-dwelling men and women from South Africa (mean age 59.7 years (SD = 15.6)) participating in the World Health Organization Study on global AGEing and adult health (WHO-SAGE) Wave 3 study collected 24 h and spot early morning urine samples over three consecutive days to assess urinary Na excretion. INTERSALT, Tanaka, and Kawasaki prediction equations, with either average or adjusted spot Na values, were used to estimate 24 h Na and compared these against measured 24 h urinary Na. Adjustment was performed by using the ratio of between-person (sb) and total (sobs) variability obtained from repeated measures analysis of variance. Sensitivity of the equations to predict daily urinary Na values below 5 g salt equivalent was calculated. The sb/sobs for urinary Na using three repeated samples for spot and 24 h samples were 0.706 and 0.798, respectively. Correction using analysis of variance for 3 × 24 h collections resulted in contraction of the upper end of the distribution curve (90th centile: 157 to 136 mmoL/day; 95th centile: 220 to 178 mmoL/day). All three prediction equations grossly over-estimated 24 h urinary Na excretion, regardless of whether a single spot urine or repeated collections corrected for intra-individual variation were used. Sensitivity of equations to detect salt intake equivalent values of ≤5 g/day was 13% for INTERSALT, while the other two equations had zero sensitivity. Correcting for intra-individual variability in Na excretion using three 24 h urine collections contracted the distribution curve for high intakes. Repeated collection of spot samples for urinary Na analysis does not improve the accuracy of predicting 24 h Na excretion. Spot urine samples are not appropriate to detect participants with salt intakes below the recommended 5 g/day.


Author(s):  
C. Terlouw ◽  
A.B. Lawrence ◽  
A.W. Illius

Animals show considerable individual variation in many behaviour patterns such as feeding and mating behaviour. Often, this individual variability is ignored in favour of a more general description of the population. However, this may mask important information regarding the causes and functions of this individual variability. Behavioural work on other species has suggested that individuals tend to respond actively or passively to environmental challenge. It is of interest to know if a similar dimension of responsiveness exists in pigs as it may serve, amongst other things, to explain the considerable individual variability in pigs responses to putitive stresses such as tethered housing. This paper describes a series of tests made of behavioural responsiveness in pigs to assess the extent of consistent variability in individuals responses to a wide variety of environmental challenges.The subjects were two groups [Group A and B: n = 26 and 36 respectively) of modern hybrid non-pregnant gilts [Cotswold Pig Development Company Ltd, UK). Initially, the gilts were subjected to a number of tests of behavioural responsiveness at the Cotswold unit.


Behaviour ◽  
2001 ◽  
Vol 138 (5) ◽  
pp. 629-648 ◽  
Author(s):  
Robert Dallmann ◽  
Thomas Geissmann

AbstractGibbon songs are known to include species- and sex-specific characteristics. It has been suggested frequently that these songs also exhibit a high degree of individuality, but quantifying individuality has rarely been attempted. Because the statistical methods used in earlier studies were highly dependent on sample size (Kruskal-Wallis one-way analysis of variance by ranks), it was not possible to compare results among studies directly. We introduce a mean pairwise difference (MPD) of scaled variables in order to quantify great-call variability and individuality. Because of its construction as simple normalised difference, the MPD is largely independent of sample size. This makes it possible to compare results directly with those of other studies on other populations or species. Even various levels of variability (intra- vs. inter-individual, intra- vs. inter-population variability) can be determined and compared with this method. In addition, the MPD can be calculated independently for any acoustic variable. This opens up a broad variety of research options in the area of comparative analysis of acoustic communication. For instance, variability in various parts of a phrase, in various parts of a song bout, in various contexts or in various seasons can be compared, and this is possible even if the variables under comparison are not the same. As an example we analysed female great-call phrases of wild silvery gibbons in Java (Indonesia). We found that inter-individual variability is significantly higher than intra-individual variability. This implies that females can be distinguished by their great-calls, although this was not examined during the present study. Additionally, variability of female songs was found to be significantly lower within one population than among any two populations. The various sections of the great-call differ in their variability. The first half of the great-call (excluding the introductory note) shows the highest potential for individual recognition.


Biomedicines ◽  
2020 ◽  
Vol 8 (2) ◽  
pp. 34 ◽  
Author(s):  
Candace R. Lewis ◽  
Katrin H. Preller ◽  
B. Blair Braden ◽  
Cory Riecken ◽  
Franz X. Vollenweider

Psilocybin is the psychoactive compound of mushrooms in the psilocybe species. Psilocybin directly affects a number of serotonin receptors, with highest affinity for the serotonin 2A receptor (5HT-2Ar). Generally, the effects of psilocybin, and its active metabolite psilocin, are well established and include a range of cognitive, emotional, and perceptual perturbations. Despite the generality of these effects, there is a high degree of inter-individual variability in subjective psilocybin experiences that are not well understood. Others have shown brain morphology metrics derived from magnetic resonance imaging (MRI) can predict individual drug response. Due to high expression of serotonin 2A receptors (5HT-2Ar) in the cingulate cortex, and its prior associations with psilocybin, we investigate if cortical thickness of this structure predicts the psilocybin experience in healthy adults. We hypothesized that greater cingulate thickness would predict higher subjective ratings in sub-scales of the Five-Dimensional Altered State of Consciousness (5D-ASC) with high emotionality in healthy participants (n = 55) who received oral psilocybin (either low dose: 0.160 mg/kg or high dose: 0.215 mg/kg). After controlling for sex, age, and using false discovery rate (FDR) correction, we found the rostral anterior cingulate predicted all four emotional sub-scales, whereas the caudal and posterior cingulate did not. How classic psychedelic compounds induce such large inter-individual variability in subjective states has been a long-standing question in serotonergic research. These results extend the traditional set and setting hypothesis of the psychedelic experience to include brain structure metrics.


2007 ◽  
Vol 363 (1497) ◽  
pp. 1699-1710 ◽  
Author(s):  
Gregory F Ball ◽  
Jacques Balthazart

Investigations of the cellular and molecular mechanisms of physiology and behaviour have generally avoided attempts to explain individual differences. The goal has rather been to discover general processes. However, understanding the causes of individual variation in many phenomena of interest to avian eco-physiologists will require a consideration of such mechanisms. For example, in birds, changes in plasma concentrations of steroid hormones are important in the activation of social behaviours related to reproduction and aggression. Attempts to explain individual variation in these behaviours as a function of variation in plasma hormone concentrations have generally failed. Cellular variables related to the effectiveness of steroid hormone have been useful in some cases. Steroid hormone target sensitivity can be affected by variables such as metabolizing enzyme activity, hormone receptor expression as well as receptor cofactor expression. At present, no general theory has emerged that might provide a clear guidance when trying to explain individual variability in birds or in any other group of vertebrates. One strategy is to learn from studies of large units of intraspecific variation such as population or sex differences to provide ideas about variables that might be important in explaining individual variation. This approach along with the use of newly developed molecular genetic tools represents a promising avenue for avian eco-physiologists to pursue.


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