Relationships between rainfall, nesting habitat and fecundity of Caiman crocodilus yacare in the Pantanal, Brazil

1995 ◽  
Vol 11 (3) ◽  
pp. 351-358 ◽  
Author(s):  
Zilca Campos ◽  
William Magnusson
Keyword(s):  
Clutch Size ◽  
Egg Size ◽  
Water Bodies ◽  
Female Size ◽  
Strong Positive Correlation ◽  
Nesting Habitat ◽  
Caiman Crocodilus ◽  
Female Body Size ◽  
Intermittent Rivers ◽  
Hatchling Size

ABSTRACTDifferences in rainfall between years influenced the proportions of different types of nesting habitats of Caiman crocodilus yacare available near water bodies in a region of intermittent rivers (Campo Dora Ranch). In contrast, rainfall had little effect on the proximity of nesting habitat to water bodies in a region of isolated lakes (Nhumirim Ranch). There was a strong positive correlation between female body size and clutch size Snout-vent lengths of females on Campo Dora Ranch were significantly larger than those from Nhumirim Ranch which probably accounts for the larger mean clutch size than in the region of isolated lakes. Hatchling size was correlated with egg size, but there was no relationship between egg size and female size or egg size and clutch size.

Clutch and egg size of the tropical lizard Tropidurus torquatus (Tropiduridae) along its geographic range in coastal eastern Brazil

2008 ◽  
Vol 86 (12) ◽  
pp. 1376-1388 ◽  
Author(s):  
M. C. Kiefer ◽  
M. Van Sluys ◽  
C. F.D. Rocha
Keyword(s):  
Body Size ◽  
Clutch Size ◽  
Female Body ◽  
Egg Size ◽  
Reproductive Investment ◽  
Geographic Range ◽  
Minimum Size ◽  
Brazilian Coast ◽  
Female Body Size ◽  
Almost All

The tropidurid lizard Tropidurus torquatus (Wied, 1820) has a set of populations inhabiting coastal sand dune habitats (“restinga”) along the eastern Brazilian coast. Despite its wide geographic range, there is no information about geographic variation in reproductive features among its populations. In the present study we compared some reproductive aspects of females in 10 coastal populations of T. torquatus, aiming to evaluate to what extension they vary geographically. The minimum size at maturity was relatively similar to most populations, but mean female body size had a considerable variation. Clutch size of almost all coastal populations of T. torquatus had little variation and was composed predominantly of two eggs. Interpopulational variation in the mean egg volume was relatively wide and strongly influenced by the variation in mean female body size. The data of the present study indicated that females of almost all coastal populations of T. torquatus produce, predominantly, clutches with two eggs and invest more energy in egg size instead of clutch size, probably as a consequence of morphological and environmental factors. The increased reproductive investment in egg size was confirmed by the values obtained for the relative clutch mass, which remained relatively constant along the coastal geographic distribution of T. torquatus.

Within-clutch egg-size variation in a subsocial bug: the positional effect hypothesis

2006 ◽  
Vol 84 (11) ◽  
pp. 1540-1544 ◽  
Author(s):  
Shin-ichi Kudo
Keyword(s):  
Predation Risk ◽  
Clutch Size ◽  
Egg Size ◽  
Size Variation ◽  
Instar Nymph ◽  
Offspring Size ◽  
Egg Mass ◽  
Female Body Size ◽  
Positional Effect ◽  
Effect Hypothesis

If there are differences in predation risk among the offspring within a clutch, parents should allocate less resources to the offspring facing higher risk. Predation risk, and thus offspring size, may depend on the spatial position of individual offspring within a clutch. To test this positional effect hypothesis, I examined egg-size (egg-mass) variation in the subsocial bug Elasmucha signoreti Scott, 1874 (Hemiptera: Acanthosomatidae). In subsocial insects, including Elasmucha , in which females guard their clutches against predators by covering the clutch with their bodies, there are large differences in survival between offspring at the centre and at the periphery of the clutch. There was considerable variation in reproductive output among females; female body size was positively correlated with egg mass but not with clutch size. Females laid significantly lighter eggs in the peripheral, and thus more vulnerable, part of the clutch. No phenotypic trade-off between egg mass and clutch size was detected. Egg mass was positively correlated with hatched first-instar nymph mass. Thus, E. signoreti females seem to allocate their resources according to the different predation risks faced by the offspring within a clutch. I suggest that the positional effect hypothesis can generally be applicable to species whose females lay eggs in clutches and that the eggs suffer different mortality rates which depend on their spatial positions within the clutch.

Female reproductive characteristics of the Balkan wall lizard (Podarcis taurica) in the northwestern periphery of its range

2010 ◽  
Vol 5 (3) ◽  
pp. 391-395 ◽  
Author(s):  
Katarina Ljubisavljević ◽  
Georg Džukić ◽  
Miloš Kalezić
Keyword(s):  
Body Size ◽  
Clutch Size ◽  
Breeding Season ◽  
Egg Size ◽  
Reproductive Traits ◽  
Species Range ◽  
Trade Off ◽  
Female Body Size ◽  
Female Reproductive Traits ◽  
Gravid Females

AbstractWe present data on the female reproductive traits of the Balkan wall lizard in the Deliblato Sand, a large continental sandland in the Pannonian area in the northwestern periphery of the species range. The clutch and egg characteristics of the population were investigated on the basis of clutches laid in laboratory conditions by gravid females captured in one locality. Balkan wall lizards produced at least two clutches in a breeding season. Individual females laid clutches of commonly two (range 1–4) eggs. The female body size had no effect on clutch and egg size. There was no trade-off between egg size and clutch size.

scholarly journals ISOMETRY OF EGG SIZE IN A TEXAS POPULATION OF THE TURTLE STERNOTHERUS ODORATUS THAT EXHIBITS A NEARLY FIXED CLUTCH SIZE

2020 ◽  
pp. 13-17
Author(s):  
Peter V. Lindeman
Keyword(s):  
Body Size ◽  
Clutch Size ◽  
Egg Size ◽  
Female Body Size ◽  
Competing Demands ◽  
Sternotherus Odoratus ◽  
Central Texas ◽  
Relationship Of ◽  
The Relationship ◽  
Anatomical Constraints

In evaluating optimal egg-size theory and the effects of anatomical constraints on egg size in turtles, pivotal questions concern the significance of the relationship of egg size to female body size and whether the relationship is isometric or hypoallometric. In a central Texas population of the kinosternid turtle Sternotherus odoratus in which clutch size of a sample of turtles was nearly fixed (seven of eight females had two eggs while the largest female had three eggs), there was an isometric increase in egg width with body size among the females with two-egg clutches and significantly reduced egg width in the largest female’s three-egg clutch. Allometric analyses of populations that exhibit little variation in clutch size, as well as analysis of modal clutch sizes in populations with more variable clutch sizes, both have the potential to further illuminate the competing demands of increasing egg size vs. increasing clutch size as females grow larger, enabling them to optimize their reproductive output as it increases with body size.

scholarly journals Variations in the reproductive strategies of three populations of Phrynocephalus helioscopus in China

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5705
Author(s):  
Tao Liang ◽  
Lu Zhou ◽  
Wenfeng He ◽  
Lirong Xiao ◽  
Lei Shi
Keyword(s):  
Body Size ◽  
Clutch Size ◽  
Reproductive Strategies ◽  
Female Body ◽  
Egg Size ◽  
Reproductive Traits ◽  
Breeding Period ◽  
Female Body Size ◽  
Trade Offs ◽  
Morphological Constraint

Background Egg size and clutch size are key life history traits. During the breeding period, it is possible for females to increase their reproductive output either by increasing the number of eggs if the optimal egg size (OES) is maintained, or by increasing the allocation of energy to each egg. However, the strategies adopted are often influenced by animals’ morphology and environment. Methods Here, we examined variation in female morphological and reproductive traits, tested for trade-offs between egg size and clutch size, and evaluated the relationship between egg size and female morphology in three populations of Phrynocephalus helioscopus. Results Female body size, egg size, and clutch size were larger in the Yi Ning (YN) and Fu Yun (FY) populations than in the Bei Tun (BT) population (the FY and YN populations laid more, and rounder eggs). Egg size was independent of female body size in two populations (BT and FY), even though both populations had an egg-size/clutch size trade-off. In the YN population, egg size and clutch size were independent, but egg size was correlated with female body size, consistent with the hypothesis of morphological constraint. Conclusions Our study found geographical variation in body size and reproductive strategies of P. helioscopus. Egg size was correlated with morphology in the larger-bodied females of the YN population, but not in the smaller-bodied females of the BT population, illustrating that constraints on female body size and egg size are not consistent between populations.

scholarly journals Reproductive ecology and territorial behavior of Boana goiana (Anura: Hylidae), a gladiator frog from the Brazilian Cerrado

2021 ◽  
Vol 38 ◽  
pp. 1-12
Author(s):  
Tailise M. Dias ◽  
Cynthia P.A. Prado ◽  
Rogério P. Bastos
Keyword(s):  
Clutch Size ◽  
Egg Size ◽  
Reproductive Ecology ◽  
Territorial Behavior ◽  
Female Size ◽  
Behavioral Strategies ◽  
Brazilian Cerrado ◽  
Male Size ◽  
Multiple Spawning ◽  
Low Incidence

Anuran males and females adopt different reproductive and behavioral strategies in different contexts. We investigated the reproductive ecology and territorial behavior of the treefrog Boana goiana (B. Lutz, 1968) from the Brazilian Cerrado. We hypothesized that competitor density/proximity would increase the behavioral responses of B. goiana males, and that mating would be assortative. We also tested if the number of eggs correlates with female size and if there is a trade-off between clutch size and egg size. We conducted two territoriality experiments to test the effects of male size, competitor proximity and competitor density. Larger males called more in the presence of a second male. In the second experiment, the largest males emitted more calls and the distance to the nearest male increased as resident males called more. In both experiments, the number of calls was influenced by either male size or spacing between males. Some males behaved as satellites, probably to avoid fights. Our analyses indicate that females choose males with similar sizes to their own, corroborating our hypothesis of size-assortative mating. We found no relationships between female size and clutch size/volume, and between egg size and number of eggs per clutch. We also report multiple spawning for this species. The low incidence of physical combats and the spacing pattern indicate that this species relies almost solely on calls to resolve contests, which could be explained by low motivation, or simply because males avoid combats to decrease injury risks. Thus, acoustic or even multimodal communication seems crucial for social interactions of B. goiana.

Breeding traits of Hermann's tortoise Testudo hermanni hermanni in two western populations

2007 ◽  
Vol 28 (1) ◽  
pp. 77-85 ◽  
Author(s):  
Marc Cheylan ◽  
Jean Pierre Nougarède ◽  
Aurelio Marín ◽  
Albert Bertolero
Keyword(s):  
Body Size ◽  
Clutch Size ◽  
Female Body ◽  
Egg Production ◽  
Reproductive Traits ◽  
Ebro Delta ◽  
Female Size ◽  
Female Body Size ◽  
Testudo Hermanni ◽  
Testudo Hermanni Hermanni

AbstractOver a period of two years we used radiology to investigate breeding traits in females of two western populations of the threatened Hermann's tortoise Testudo hermanni hermanni. The main purpose of the study was to see if reproductive traits – clutch size, clutch frequency, annual egg production and egg width – varied between populations in Corsica (France) and the Ebro Delta (Spain), and if these traits were affected by female body size and amounts of spring rainfall. All the breeding traits analysed were greater in the Corsican population than in the Ebro Delta population. These differences were also significant when we used female body size as a covariable. In both populations the amount of spring rainfall affected breeding traits but not clutch size. Nevertheless, only in the Corsican population did clutch frequency, annual egg production and egg width increase significantly in the year with a wet spring. Contrary to the predictions of Optimal Propagule Size theory, we found that egg size and clutch size increased with female size, and that both variables were independent. On the other hand, clutch frequency was not related to female body size. Thus, in the Hermann's tortoise, as clutch size did not change between years and clutch frequency was independent of female size, all females are able to increase their reproductive output in years with favourable conditions by increasing their clutch frequency. Nevertheless, other factors besides female size and rainfall may influence in a highly complex way variability in breeding traits among populations.

scholarly journals Relationships among female body size, clutch size, and egg size in captiveDeinagkistrodon acutus

2013 ◽  
Vol 33 (6) ◽  
pp. 1778-1783 ◽  
Author(s):  
胡明行 HU Minghang ◽  
谭群英 TAN Qunying ◽  
杨道德 YANG Daode
Keyword(s):  
Body Size ◽  
Clutch Size ◽  
Female Body ◽  
Egg Size ◽  
Female Body Size

scholarly journals Reproductive trade-offs of the estuarine copepod Eurytemora affinis under different thermal and haline regimes

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Anissa Souissi ◽  
Jiang-Shiou Hwang ◽  
Sami Souissi
Keyword(s):  
Clutch Size ◽  
Egg Size ◽  
Abiotic Factors ◽  
Negative Relationship ◽  
Cold Temperature ◽  
Female Size ◽  
Eurytemora Affinis ◽  
Trade Off ◽  
Trade Offs ◽  
Higher Temperature

AbstractCopepod females invest a quantity of resources in their reproduction. Depending on several biotic and abiotic factors and their evolutionary history a trade-off can be commonly observed between producing a large number of smaller offspring or a small number of larger offspring. In this study, a multi-generational approach was applied to determine whether a trade-off between clutch size and egg size existed in the copepod Eurytemora affinis under different controlled conditions of temperature and salinity. This protocol was based on the follow-up of reproductive (Clutch Size ‘CS’, Egg Diameter ‘ED’) and morphological (Prosome Length ‘PL’) traits during several generations. Copepods were acclimated to cold (7 °C) and warm (20 °C) temperatures, and then their reproductive output was tested at the higher temperature of 24 °C. CS and ED were positively correlated to PL, so as a first step linear regressions between each reproductive trait and female PL were performed. The residuals from the regression lines of CS and ED with PL were calculated to remove the effect of female size. When the normalized data (residuals) of CS and ED plotted together a negative relationship between egg size and egg number revealed the existence of a trade-off. Copepod populations initially acclimated to cold temperature are commonly characterized by relatively smaller CS and larger ED. Conversely, warm temperature adapted females produced relatively larger CS and smaller ED. After transfer to a temperature of 24 °C, the ED did not change but the CS showed high variability indicating stressful conditions and no trade-off was observed. These observations suggest that E. affinis is able to modulate its reproduction depending on the encountered temperature. It seems that this copepod species can shift between a K- and an r-strategy in response to colder or warmer conditions. In a late winter-early spring like cold temperature, copepod females seem to invest more on offspring quality by producing relatively larger eggs. This ecological strategy ensures a high recruitment of the spring generation that is responsible for the strength of the maximum population size usually observed in late spring-early summer (May–June). To the contrary, at summer-like temperature, where the population density decreases significantly in the Seine estuary, copepod females seem to switch from K to r strategy by favoring offspring number compared to offspring size. Finally, the use of a higher temperature of 24 °C seems to disrupt the observed reproductive trade-off even after several generations. These results suggest that a switching between K- or r-strategy of E. affinis depends highly on temperature effects. The effect of salinity increase during a summer-like temperature of 20 °C as well as after transfer to 24 °C decreased PL and CS but the ED did not change significantly.

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