scholarly journals Delayed effects of prey fish quality and winter temperature during the birth year on adult size and reproductive rate of Baltic grey seals

2019 ◽  
Vol 65 (1) ◽  
pp. 117-126
Author(s):  
Kaarina Kauhala ◽  
Mika Kurkilahti
Keyword(s):  
Body Size ◽  
Body Condition ◽  
Birth Rate ◽  
Reproductive Rate ◽  
Winter Temperature ◽  
Clupea Harengus ◽  
Adult Size ◽  
Prey Fish ◽  
Fish Quality ◽  
Delayed Effects

Abstract Environmental conditions of mammalian juveniles may have delayed effects on their life histories and fitness, such as body size or reproductive rate later in their lives. In the present study, we tested this hypothesis on Baltic grey seals (Halichoerus grypus) and examined (1) the possible effects of prey fish quality and winter temperature on body condition of grey seal pups of both sexes and (2) the possible delayed impacts of pup environment on the body size and birth rate of adult grey seals. Body condition (blubber thickness) of especially female pups in April–May correlated negatively with winter temperatures, and body condition of male pups correlated positively with prey fish quality (herring Clupea harengus and sprat Sprattus sprattus weight). Males reached the asymptotic length at the age of 10.3 years, and body length of adult males (≥ 10 years old) was positively related to herring and sprat weight in their birth year. Females reached the asymptotic length at the age of 5.9 years. Birth rate of females (age 7–24 years) was negatively related to winter temperature in their birth year. We conclude that both changes in prey fish quality and climate may affect body condition of pups and thus also cause delayed effects on adult fitness: body size and reproductive rate of Baltic grey seals.

scholarly journals Age of maturation and behavioral tactics in male yellow ground squirrel Spermophilus fulvus during mating season

2014 ◽  
Vol 60 (6) ◽  
pp. 700-711 ◽  
Author(s):  
Nina A. Vasilieva ◽  
Ekaterina V. Pavlova ◽  
Sergey V. Naidenko ◽  
Andrey V. Tchabovsky
Keyword(s):  
Body Size ◽  
Ground Squirrel ◽  
Life History Theory ◽  
Social Activity ◽  
Indirect Evidence ◽  
Adult Size ◽  
Adult Males ◽  
Mating Season ◽  
Active Season ◽  
Good Physical Condition

Abstract Life-history theory predicts that in hibernators age of maturation is related positively to body size and negatively to the duration of active season aboveground. Yellow souslik is a large-sized ground squirrel with long hibernation, which suggests late maturation. We used four-year field observations of marked individuals to determine the age of maturation in males through analysis of age-dependent variation in body size, mass, androgen status, timing of spring emergence, ranging patterns and social behavior during the mating season. Yearling males were smaller, lighter, had lower level of fecal testosterone, emerged later and had smaller home ranges than older males. Social activity and the number of females encountered did not differ between age classes. After the second hibernation none of the studied parameters varied with age. Cluster analysis revealed two behavioral tactics: “active” males (adults only) emerged earlier, ranged more widely, initiated more contacts, encountered more females and were heavier than “passive” males (both yearling and adult). Thus, males of S. fulvus reached adult size and matured after two hibernations, which is relatively fast for such a big species with short active period. Indirect evidence for copulations and high variation among yearlings in all parameters suggest that some of them might successfully compete with adults. Active tactic of wandering and searching for females is energetically costly, and probably only adult males in good physical condition can afford it, whereas passive tactic of residing is energy saving and good for adults in poor condition and for yearlings that are continuing to grow.

scholarly journals Life history and habitat do not mediate temporal changes in body size due to climate warming in rodents

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9792
Author(s):  
Aluwani Nengovhela ◽  
Christiane Denys ◽  
Peter J. Taylor
Keyword(s):  
Life History ◽  
Body Size ◽  
Climate Warming ◽  
Life History Traits ◽  
Vegetation Type ◽  
Reproductive Rate ◽  
Temporal Changes ◽  
Temporal Response ◽  
Extrinsic Factors ◽  
African Species

Temporal changes in body size have been documented in a number of vertebrate species, with different contested drivers being suggested to explain these changes. Among these are climate warming, resource availability, competition, predation risk, human population density, island effects and others. Both life history traits (intrinsic factors such as lifespan and reproductive rate) and habitat (extrinsic factors such as vegetation type, latitude and elevation) are expected to mediate the existence of a significant temporal response of body size to climate warming but neither have been widely investigated. Using examples of rodents, we predicted that both life history traits and habitat might explain the probability of temporal response using two tests of this hypothesis. Firstly, taking advantage of new data from museum collections spanning the last 106 years, we investigated geographical and temporal variation in cranial size (a proxy for body size) in six African rodent species of two murid subfamilies (Murinae and Gerbillinae) of varying life history, degree of commensality, range size, and habitat. Two species, the commensal Mastomys natalensis, and the non-commensal Otomys unisulcatus showed significant temporal changes in body size, with the former increasing and the latter decreasing, in relation with climate warming. Commensalism could explain the increase in size with time due to steadily increasing food availability through increased agricultural production. Apart from this, we found no general life history or habitat predictors of a temporal response in African rodents. Secondly, in order to further test this hypothesis, we incorporated our data into a meta-analysis based on published literature on temporal responses in rodents, resulting in a combined dataset for 50 species from seven families worldwide; among these, 29 species showed no significant change, eight showed a significant increase in size, and 13 showed a decline in size. Using a binomial logistic regression model for these metadata, we found that none of our chosen life history or habitat predictors could significantly explain the probability of a temporal response to climate warming, reinforcing our conclusion based on the more detailed data from the six African species.

The effect of body size and body condition on the ovulation rate of ewes

1977 ◽  
Vol 24 (3) ◽  
pp. 377-385 ◽  
Author(s):  
M. J. Ducker ◽  
J. S. Boyd
Keyword(s):  
Body Size ◽  
Breeding Season ◽  
Body Condition ◽  
Live Weight ◽  
Ovulation Rate ◽  
Subjective Measure ◽  
Body Dimensions ◽  
The Mean ◽  
Per Se ◽  
Linear Body

SUMMARYBody size was estimated for 255 Greyface ewes using five linear body dimensions. On the basis of this calculated measure combined with a subjective measure of body size 50 small and 50 large ewes were selected for use in the experiment. Precise ovulation data were obtained by endoscopy and this technique allowed the ewes to be mated subsequently.Body size did not affect the mean ovulation rate of the ewes although, at the same level of body condition, the large ewes were 25% heavier than the small ewes. The ovulation rates and the numbers of lambs born were influenced by changes in live weight and body condition. For these reasons live weight per se was not a good indicator of ovulation rate as ewe live weight was a combination of both body size and body condition. At the same live weight small ewes in improving body condition had a significantly higher ovulation rate than large ewes in reducing body condition.The onset of the breeding season of the ewes was not affected by their body size. The mean date of onset of oestrous activity for both large and small ewes was 17 October 1972 at a latitude 55° 52′ N.

Comparing three body condition indices in amphibians: a case study of yellow-bellied toad Bombina variegata

2010 ◽  
Vol 31 (4) ◽  
pp. 558-562 ◽  
Author(s):  
Rodica Plăiaşu ◽  
Tibor Hartel ◽  
Raluca Ioana Băncilă ◽  
Dan Cogălniceanu ◽  
Joost Smets
Keyword(s):  
Body Size ◽  
Body Condition ◽  
Condition Index ◽  
Quality Parameters ◽  
Direct Measurements ◽  
Wide Range ◽  
Bombina Variegata ◽  
Condition Indices ◽  
Three Body

AbstractBody condition is important because it is correlated with population and habitat quality parameters. Since the direct measurements are either lethal or unreliable, a wide range of non-lethal body condition indices has been proposed. The aim of our study was to apply and compare three body condition indices (Fulton's index, relative body condition mass index and residual index) using body size indicator – body mass data for 24 populations of the yellow bellied toad (Bombina variegata). The condition index should be independent of body size indicator, in this case snout vent length (SVL). Therefore we tested all three indices for the statistical independence of SVL and for the normality of distribution. Fulton's index violated the independence assumption, whereas the relative body condition mass index did not have a normal distribution. Residual index was found both independent of SVL and normally distributed. Moreover, the residual index highlighted biological significant differences on the basis of altitude and season. Our results recommend the residual index as a useful tool in amphibian monitoring and conservation.

Effects of initial (larval) size and host body temperature on growth in trematodes

2003 ◽  
Vol 81 (4) ◽  
pp. 574-581 ◽  
Author(s):  
Robert Poulin ◽  
A David M. Latham
Keyword(s):  
Body Size ◽  
Body Temperature ◽  
Adult Stage ◽  
Species Variation ◽  
Adult Size ◽  
Model Group ◽  
Larval Size ◽  
Relative Growth ◽  
Host Body ◽  
Adult Body

For ectotherms, temperature is an important correlate of variation in body size within species. Variation in body size among related species could also be attributable in part to temperature if the different species grow under different thermal regimes. The roles of both initial (larval) size and host body temperature on final (adult) size of parasitic trematodes were investigated in a comparative analysis. Trematodes are a good model group for such a study, with almost half of known species growing at high and constant temperatures in endothermic vertebrates and the rest at lower and fluctuating temperatures in ectothermic vertebrates. The relative growth of trematodes, i.e., their growth relative to the size of their larvae, varied greatly among species. Increases in body size from the cercarial larval stage to the adult stage averaged almost 40-fold (maximum 1300-fold), whereas increases in size from the metacercarial stage to the adult stage averaged 6-fold (maximum 110-fold). There were no differences between trematodes in ectothermic hosts and trematodes in endothermic hosts with respect to these measures of relative growth, however, which suggests that host type and the thermal regime provided by the host have no effect on the growth of trematodes from larval to adult stages. In contrast, the final (adult) body size of trematodes appears to be determined to some extent by their initial (larval) size, independently of the type of host in which they developed.

Phenotypic indicators of developmental instability in an endemic amphibian from an altered landscape (Monegros, NE Spain)

2013 ◽  
Vol 34 (4) ◽  
pp. 505-516 ◽  
Author(s):  
Carmen Burghelea ◽  
Dragos Zaharescu ◽  
Antonio Palanca
Keyword(s):  
Body Size ◽  
Body Condition ◽  
Habitat Degradation ◽  
Great Sensitivity ◽  
Rice Fields ◽  
Land Disturbance ◽  
Agricultural Conversion ◽  
Highly Sensitive ◽  
Pelophylax Perezi ◽  
Ne Spain

The great sensitivity of amphibians to land disturbance is one of the main causes that contributed to their worldwide decline. One fundamental approach in assessing amphibian ability to reflect habitat degradation is to measure their phenotypic changes in contrasting environments. We examined the extent to which several morphological traits of the endemic anuran Pelophylax perezi responded to agricultural conversion in Monegros, an arid region in NE Spain. Specifically, we determined how body size, body mass, body condition (BC) and fluctuating asymmetry (FA) of different frog classes varied among habitats with different degree of management, i.e. rice fields vs. control ponds (i.e. small reservoirs). Pelophylax perezi juveniles showed a decrease in size and mass in rice fields, revealing that early life stages are generally more susceptible to habitat alteration. Adult body condition, on the other hand, increased significantly in cultivated habitats, which apparently indicates a good fitness in this size class. Nonetheless, skeletal asymmetry of both, juveniles and adults was significantly higher in rice fields. Moreover, during postmetamorphic development FA increased significantly towards adult stage indicating that the development controlling mechanisms were not able to buffer the stress induced by land use change. Among traits, humerus, radio-ulna and metatarsal were highly sensitive in terms of expressing significant FA differences between habitats, contrary to tibio-fibula, whose precise symmetry is essential for animal locomotion. The former bones have therefore the potential to be used as sensitive indicators of stress in amphibians. FA showed no relationship with body condition. This, together with the previous results demonstrates that FA is able to capture habitat stress more reliably than the morphological estimates such as body size, mass and BC. Therefore, FA is a useful morphological tool, highly recommended to monitor stress levels in amphibian populations.

An investigation of factors influencing erythrocyte morphology of red-backed salamanders (Plethodon cinereus)

2009 ◽  
Vol 59 (2) ◽  
pp. 201-209 ◽  
Author(s):  
John Maerz ◽  
Joseph Milanovich ◽  
Andrew Davis ◽  
Jayna DeVore
Keyword(s):  
Body Size ◽  
Body Condition ◽  
Oxygen Demand ◽  
Plethodon Cinereus ◽  
Future Research ◽  
Health State ◽  
Erythrocyte Morphology ◽  
Size And Shape ◽  
Plethodontid Salamanders ◽  
Body Sizes

AbstractAmphibians have long been known to display wide variation in erythrocyte morphology across species, but within species there has been little attention given to individual variation in red blood cell morphology. We captured 49 red-backed salamanders (Plethodon cinereus) from central Pennsylvania, USA and used image analysis procedures to measure erythrocyte morphology (size and shape) on blood smears made from all individuals. We then statistically examined whether variation in snout-vent-length, sex, tail loss, or capture location influenced these cell variables. Only snout-vent-length affected erythrocyte size and shape, with increasing body sizes associated with increasing cell areas and increasingly rounder cells. Further, erythrocyte shape was also associated with a measure of body condition that was corrected for body size, such that individuals with high body condition scores had rounder cells. Given the oxygen-carrying role of erythrocytes in all vertebrates, we suspect this discovery is related to size-related changes in oxygen demand, since total oxygen consumption increases with body size in an allometric manner. While our results warrant further investigation to understand the mechanism, the association we found between cell roundness and both body size and condition nevertheless indicates this parameter could be used to assess the health state of plethodontid salamanders in future research, provided non-destructive sampling is employed. Our results also underscore the value of hematological investigations in the study of animal biology.

The effects of components of body weight on reproductive efficiency in the Merino ewe

1972 ◽  
Vol 78 (2) ◽  
pp. 245-249 ◽  
Author(s):  
J. C. Guerra ◽  
C. J. Thwaites ◽  
T. N. Edey
Keyword(s):  
Body Weight ◽  
Body Size ◽  
Linear Regression ◽  
Body Condition ◽  
Experimental Period ◽  
Ovulation Rate ◽  
Reproductive Efficiency

SUMMARYGroups of mature Merino ewes selected on the basis of either large or small bodysize were differentially fed during a pre-experimental period to produce subgroups of high and low body condition. These levels of body condition were maintained for 2 weeks before mating and for the first 5 weeks of gestation. Thereafter, the four subgroups grazed together until lambing.Big ewes had more multiple ovulations than small ewes (14/41 υ 6/53; P < 0·01), and there was a significant linear regression of ovulation rate on body size. Body condition was positively related to the incidence of multiple ovulations, but the regression of ovulation rate on body condition at mating failed to reach significance. Body weight was significantly related to both ovulation rate and the incidence of multiple ovulations, and proved to be a more effective predictor of ovulation rate than either body size or condition.These results make it clear that size and condition, the two components of body weight, each have a considerable independent influence on some aspects of reproduction, and that the precision of some experiments and the effectiveness of some production routines could be improved by considering them separately.

New smallest specimen of the pterosaurPteranodonand ontogenetic niches in pterosaurs

2017 ◽  
Vol 92 (2) ◽  
pp. 254-271 ◽  
Author(s):  
S. Christopher Bennett
Keyword(s):  
Body Size ◽  
Parental Care ◽  
Large Body ◽  
Taxonomic Diversity ◽  
Ecological Niches ◽  
Adult Size ◽  
Niobrara Formation ◽  
Large Body Size ◽  
Juvenile Specimen

AbstractA new juvenile specimen ofPteranodonfrom the Smoky Hill Chalk Member of the Niobrara Formation of western Kansas had an estimated wingspan in life of 1.76 m, ~45% smaller than the smallest previously known specimens, but does not differ in morphology from larger specimens. Its presence indicates that juveniles were capable of flying long distances, so it falsifies the interpretation ofPteranodonas growing rapidly to adult size under parental care before flying. Instead juveniles were precocial, growing more slowly to adult size while flying and feeding independently for several years before going to sea. Because juveniles are otherwise unknown in the Smoky Hill Chalk Member, they must have occupied different environments and ecological niches than adults; thusPteranodonexhibited ontogenetic niches. Evidence is presented that most other pterosaurs (e.g.,Rhamphorhynchus,Pterodactylus,Anhanguera) also exhibited various ontogenetic niches, which, along with their large body size, suggests that pterosaur taxonomic diversity was rather low, like that of crocodilians.

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