Avian Egg Morphometrics - Allometric Models of Egg Volume, Clutch Volume and Shape

1994 ◽  
Vol 42 (3) ◽  
pp. 307 ◽  
Author(s):  
PD Olsen ◽  
RB Cunningham ◽  
CF Donnelly

This paper describes three comprehensive new models of the allometric relationships between egg volume, clutch volume and shape, and body weight. Mean egg dimensions, clutch sizes and adult body weights were obtained for 326 species, mainly of four bird types: raptors (including owls), shorebirds, frogmouths (including nightjars), and storks (including the New World vultures). These are groups in which there is a wide range of body sizes and of sexual dimorphism in body size (in direction and degree). Female body weight alone accounted for 92% of the variation in egg volume. Sexual dimorphism in body size, phylogenetic relationship, and clutch size were significant contributors to the model of egg volume; their addition increased the explained variance to over 98%. The model was curvilinear (quadratic) in form, rather than linear as assumed in previous models. Larger species laid smaller eggs than expected under a simple power function. For the fitted model, within bird types, generic groupings had parallel curvilinear slopes but differing intercepts. Between bird types, the slopes differed. Clutch volume was scaled to body weight; all the bird types had a common slope, which was curvilinear. Body weight and dimorphism accounted for 89.5% of the variation in clutch volume. For all bird types, eggs became proportionally longer in shape as body weight increased, according to a simple power law. The relevance of these relationships to hypotheses on the evolution and adaptive significance of sexual dimorphism and to the trade-off between egg size and clutch size is discussed briefly.

1988 ◽  
Vol 3 (3) ◽  
pp. 193-196 ◽  
Author(s):  
S. Barni ◽  
P. Lissoni ◽  
S. Crispino ◽  
F. Rovelli ◽  
G. Esposti ◽  
...  

Melatonin secretion is often enhanced in patients with cancer. In the light of a reported correlation between melatonin levels and body size, we investigated blood levels of this pineal hormone in a group of 72 patients affected by cancer, 30 of whom had body weight within the normal range, 30 were obese and the last 12 cases had body weight below the normal range, in order to establish whether in fact melatonin blood concentrations were related to body size. Melatonin levels were high in 19/72 patients (26%). The mean levels of the pineal hormone were similar in patients with normal, low and high body weight. Finally, there was no significant correlation between melatonin values and body weight, height or surface. Melatonin secretion thus does not appear to be influenced by body size in cancer patients.


2014 ◽  
Vol 10 (6) ◽  
pp. 20140261 ◽  
Author(s):  
John P. DeLong

The parameters that drive population dynamics typically show a relationship with body size. By contrast, there is no theoretical or empirical support for a body-size dependence of mutual interference, which links foraging rates to consumer density. Here, I develop a model to predict that interference may be positively or negatively related to body size depending on how resource body size scales with consumer body size. Over a wide range of body sizes, however, the model predicts that interference will be body-size independent. This prediction was supported by a new dataset on interference and consumer body size. The stabilizing effect of intermediate interference therefore appears to be roughly constant across size, while the effect of body size on population dynamics is mediated through other parameters.


2008 ◽  
Vol 25 (2) ◽  
pp. 370-372 ◽  
Author(s):  
Carlos Frederico Duarte Rocha

In this study 57 specimens of the lizard Ameiva ameiva (Linnaeus, 1758) collected in the restinga at Barra de Maricá, in the state of Rio de Janeiro, southeastern Brazil, were analyzed to investigate size relations and reproduction (in females) and sexual dimorphism of this population. We answered the following questions: 1) what is the minimum reproductive body size in females? 2) what is the average clutch size and 3) how is clutch size related to body size? 4) Are body and head sizes sexually dimorphic? Mean clutch size was 6.7 ± 2.1 eggs and was positively correlated with female body size. Sexual dimorphism favoring males was found: adult mean snout-vent length was great in males (124.2 ± 17.8 mm) than females (96.5 ± 23.1 mm SVL), and males were larger with respect to head width and length, and body mass. Thus, despite the marked seasonality at Barra de Maricá, A. ameiva has an extended reproductive period. Also, intrasexual selection may have acted on females to produce larger clutches, and on males, favoring larger males.


2012 ◽  
Vol 30 (15_suppl) ◽  
pp. TPS2622-TPS2622 ◽  
Author(s):  
Shruti Agrawal ◽  
Yan Feng ◽  
Georgia Kollia ◽  
Sally Saeger ◽  
Martin Ullmann ◽  
...  

TPS2622 Background: BMS-936558 is a fully human IgG4 monoclonal antibody targeted against human Programed Death-1 (PD1) receptor on activated T and B lymphocytes. Blocking of PD-1 prevents these activated cells from becoming anergic, thereby maintaining anti-tumor immunologic activity. Methods: The PK of BMS-936558 was characterized with data from a single ascending dose (SAD) and a multiple ascending dose (MAD) study in subjects with advanced solid malignancies. Subjects received a single IV infusion of 0.3 to 10 mg/kg BMS-936558 in the SAD study (MDX-1106-01 Study) and 0.1 to 10 mg/kg BMS-936558 every two weeks in the MAD study (MDX-1106-03/CA209003 Study). The PK of BMS-936558 was characterized by non-compartmental analysis of intensively sampled PK data from a SAD study, as well as by population PK analysis of available intensive and sparse PK data from the SAD and MAD studies, respectively. Results: The PK of BMS-936558 is linear in the studied dose range with dose-proportional increase in Cmax and AUC with low to moderate (20-44%) inter-subject variability. Geometric mean clearance ranged from 0.13 - 0.19 mL/h/kg, whereas mean volume of distribution ranged from 83 -113 mL/kg. The range of mean terminal elimination half-life of BMS-936558 is 17 to 25 days which is consistent with half-life of endogenous IgG4. BMS-936558 PK was adequately described by a linear two-compartment model, and there was no evidence of a contribution of target mediated drug disposition to drug elimination within tested dose range. Body weight and gender are potentially clinically significant covariate for both clearance and volume of distribution (> 20% effect); and baseline CRP, LDH, and albumin are potentially clinically significant covariates for CL. The body weight normalized dosing employed produces trough concentrations that are approximately constant over a wide range of body weights. Conclusions: The pharmacokinetics of BMS-936558 is dose-proportional and body weight normalized dosing is appropriate to ensure consistent exposure over a wide range of body weights.


2014 ◽  
Vol 86 (3) ◽  
pp. 1263-1272 ◽  
Author(s):  
DJAN ZANCHI-SILVA ◽  
DIVA M. BORGES-NOJOSA ◽  
CONRADO A.B. GALDINO

The reproductive ecology of Ameivula ocellifera was studied from September 2009 to August 2010 in a coastal area of the state of Ceará, Brazil. Females reproduced continuously throughout the year, with a peak at the end of the rainy season. Even though there was a predominance of pre-reproductive individuals in the sample, gonadal activity of males peaked synchronously to female reproduction. Mean clutch size was 1.98 ± 0.56 and positively associated with female body size, while mean egg volume was 510.54 ± 84.29 mm3 and unrelated to female body size. We did not find any association between clutch size and average egg volume.


1971 ◽  
Vol 76 (3) ◽  
pp. 433-441 ◽  
Author(s):  
R. J. Colyer

SUMMARYObservations were made on the development of the testes and epididymides of thirty-two Clun Forest ram lambs. There were no significant differences between the weights and volumes of the left and right testes and epididymides.The rate of increase in testicular and epididymal weights was linear up to a body weight of 46 lb (20·9 kg) followed subsequently by a significantly greater rate of increase at higher body weights. Similar patterns of growth occurred in relation to age, although at a given age there was a wide range of testicular and epididymal weights. There was a close relationship between the development of the testis and the epididymis at body weights greater than 46 lb (20·9 kg).There were two distinct phases in the dimensional growth of the testis. Increases in testicular length and breadth proceeded at much the same rate at testis weights of below 20 g. During the subsequent phase testicular length increased at a significantly greater rate than testis breadth.


1999 ◽  
Vol 20 (4) ◽  
pp. 377-389 ◽  
Author(s):  
J. Scott Keogh ◽  
V. Wallach

AbstractWe quantified sexual dimorphism and allometric changes in the lung morphology of 160 juvenile and adult specimens of prairie rattlesnake, Crotalus viridis viridis, from a single population. In virtually all lung components, those of males are located more posteriorly than are those of females of the same body size. Males display a longer vascular component than females but there is no sexual dimorphism in size of the avascular component. Thus, males generally have longer lungs than do females at all body sizes. With increasing body size, the lung components are found more anteriorly, relative length of the vascular lung decreases, and relative length of the avascular lung increases in both sexes. However, total lung length increases isometrically with body size. These sexual and allometric differences suggest that intraspecific variation should be taken into account when lung size characters are used in snake systematic studies.


2006 ◽  
Vol 27 (1) ◽  
pp. 37-46 ◽  
Author(s):  
Lígia Pizzatto ◽  
Otavio Marques

AbstractSexual maturity, sexual dimorphism, reproductive output, and parasitism of the colubrid snake Liophis miliaris were compared among populations inhabiting four regions of Brazil: (1) northern coastal Atlantic forest, (2) southern coastal Atlantic forest, (3) northern inland Atlantic forest (4) southern inland Atlantic forest. Females delayed maturity and attained larger body sizes than males in all regions. Males and females from northern Atlantic forest were smaller and attained maturity with a smaller body size than males of other regions. The sexual size dimorphism index ranged from 0.19 to 0.23 and was lowest in the northern Atlantic forest. There was no sexual dimorphism in head length in any of the populations studied. Clutch size was similar in all populations and increased with maternal body size. The reproductive frequency was lower in the northern coastal Atlantic forest and in contrast to the other regions, tended to increase with female body size. The nematoda Ophidiascaris sp. and cystacanths of Oligacanthorynchus spira (Acanthocephala) occurred equally in both sexes. Fewer snakes from the northern coastal Atlantic forest were infested by parasites compared to the other regions and parasitism apparently did not influence reproduction.


1990 ◽  
Vol 68 (4) ◽  
pp. 672-677 ◽  
Author(s):  
Jeffrey E. Lovich ◽  
Carl H. Ernst ◽  
John F. McBreen

Growth in the wood turtle (Clemmys insculpta) is described using the von Bertalanffy growth model and nonlinear regression. Growth in both sexes is similar until about 160 mm plastron length. Males grew at a faster rate after this size. Males appear to mature at a larger size and later age than females, although age-specific body size is highly variable. Sexual size dimorphism, in carapace length, is pronounced, with males attaining mean body sizes significantly larger (1.07–1.10 times) than those of adult females. Plastron length is an inappropriate measure of sexual size dimorphism because of the development of plastral concavity in males. Females tend to predominate in samples, possibly owing to differential maturity of the sexes. The direction of sexual size dimorphism may be maintained by intrasexual competition among males for access to females. Data for several adults captured at intervals of from 9 to 20 years support the concept of indeterminate growth.


1960 ◽  
Vol 199 (5) ◽  
pp. 863-866
Author(s):  
Charles A. Winter ◽  
Lars Flataker

Fasted rats trained to climb a rope for a food reward were capable of carrying added weights approximately equal to their own body weights. The logclimbing time in seconds was linearly related to the total weight of the animal plus added load within a narrow range of body weight. When correction was made for skeletal muscle mass, the rate of work performance in gram-meters per long second per gram muscle was essentially the same over a wide range of body weights and of added load. Work performance as measured by this preparation was sensitive to changes in glucocorticoid levels, and was increased by cortisone or hydrocortisone in either intact or adrenalectomized animals, and was decreased by adrenal insufficiency.


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