Optimal egg size in a suboptimal environment: reproductive ecology of female Sonora mud turtles (Kinosternon sonoriense) in central Arizona, USA

2012 ◽  
Vol 33 (2) ◽  
pp. 161-170 ◽  
Author(s):  
Jeffrey E. Lovich ◽  
Sheila V. Madrak ◽  
Charles A. Drost ◽  
Anthony J. Monatesti ◽  
Dennis Casper ◽  
...  
Keyword(s):  
Clutch Size ◽  
Egg Size ◽  
Carapace Length ◽  
Reproductive Ecology ◽  
X Ray ◽  
Adult Females ◽  
Aperture Width ◽  
Montezuma Well ◽  
Morphological Constraint ◽  
Central Arizona

We studied the reproductive ecology of female Sonora mud turtles (Kinosternon sonoriense) at Montezuma Well, a chemically-challenging natural wetland in central Arizona, USA. Females matured between 115.5 and 125 mm carapace length (CL) and 36-54% produced eggs each year. Eggs were detected in X-radiographs from 23 April-28 September (2007-2008) and the highest proportion (56%) of adult females with eggs occurred in June and July. Clutch frequency was rarely more than once per year. Clutch size was weakly correlated with body size, ranged from 1-8 (mean = 4.96) and did not differ significantly between years. X-ray egg width ranged from 17.8-21.7 mm (mean 19.4 mm) and varied more among clutches than within. Mean X-ray egg width of a clutch did not vary significantly with CL of females, although X-ray pelvic aperture width increased with CL. We observed no evidence of a morphological constraint on egg width. In addition, greater variation in clutch size, relative to egg width, suggests that egg size is optimized in this hydrologically stable but chemically-challenging habitat. We suggest that the diversity of architectures exhibited by the turtle pelvis, and their associated lack of correspondence to taxonomic or behavioral groupings, explains some of the variation observed in egg size of turtles.

Reproductive ecology of the painted turtle (Chrysemys picta marginata) in southwestern Quebec

1986 ◽  
Vol 64 (4) ◽  
pp. 914-920 ◽  
Author(s):  
Elaine Christens ◽  
J. Roger Bider
Keyword(s):  
Body Size ◽  
Clutch Size ◽  
Egg Size ◽  
Reproductive Ecology ◽  
Substantial Reduction ◽  
Chrysemys Picta ◽  
Painted Turtle ◽  
X Ray ◽  
Painted Turtles ◽  
Old Females

The reproductive ecology of painted turtles (Chrysemys picta marginata) was studied over 3 years (1983–1985) in southwestern Quebec. We used X-ray photography to determine clutch size, egg size, and clutch frequency in conjunction with radiotelemetry to determine when and where the eggs were being deposited. Data on nesting frequency indicated that between 40 and 80% of the 7- to 11-year-old females reproduce each year. All females > 11 years of age reproduced each year and exhibited a substantial reduction in growth compared with younger adult females. The percentage of those females that layed two clutches in a season ranged from 5 to 32%. There was no difference in the size of the first and second clutches or those produced by females only laying one clutch. The average clutch size was found to be 9.2 (range, 5–12) eggs. There was no significant relationship between clutch size and body size, between clutch size and age, or between clutch size and egg size. There was a significant positive linear relationship between egg size and body size. Age-specific fecundity increased up to 20 years of age and then decreased. When compared to studies of more southern populations of painted turtles, the major reproductive strategy for this population seems to be to produce a larger number of large eggs per clutch.

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.

Parental Investment in Clutch Size and Egg Size in the Ural Owl Strix uralensis

1986 ◽  
Vol 17 (4) ◽  
pp. 309 ◽  
Author(s):  
Hannu Pietiainen ◽  
Pertti Saurola ◽  
Risto A. Vaisanen
Keyword(s):  
Clutch Size ◽  
Parental Investment ◽  
Egg Size ◽  
Ural Owl

scholarly journals Male harassment leads to fitness costs for females by disrupting oviposition site preferences

2020 ◽  
Vol 31 (3) ◽  
pp. 611-617
Author(s):  
Elisabeth Bacon ◽  
Flavia Barbosa
Keyword(s):  
Clutch Size ◽  
Sexual Conflict ◽  
Egg Size ◽  
Callosobruchus Maculatus ◽  
Optimal Number ◽  
Oviposition Site ◽  
Fitness Costs ◽  
Male Harassment ◽  
Oviposition Substrate ◽  
Pinto Beans

Abstract In many species, a difference in the optimal number of copulations for males and females leads to sexual conflict. This is well documented in the bean beetle Callosobruchus maculatus, where both sexes mate multiply and females incur fitness costs from injuries caused by the male genitalia. Here, we demonstrate that sexual conflict also decreases female fitness due to male harassment. We hypothesized that harassment costs would come as 1) decreased clutch size, egg size, or both and by 2) disruption of female preference for higher-quality oviposition substrate. Mated females were housed with two bean types—cowpeas, their preferred natal hosts, and toxic pinto beans. They were then submitted to either no, moderate, or high male harassment in the oviposition site. Females under harassment produced smaller clutch sizes but not smaller eggs, resulting in the absence of an egg-size/clutch-size trade-off. Additionally, females did not exhibit a preference for their natal cowpeas hosts over toxic pinto beans when males were present at the oviposition site, although they do so when harassing males are not present. Harassment disrupted female responses to variation in oviposition substrate quality, resulting in considerable fitness consequences in the form of lower offspring production and survival.

Annual variations in reproductive characteristics of painted turtles (Chrysemys picta)

1986 ◽  
Vol 64 (5) ◽  
pp. 1148-1151 ◽  
Author(s):  
Lin Schwarzkopf ◽  
Ronald J. Brooks
Keyword(s):  
Body Size ◽  
Clutch Size ◽  
Repeated Measures ◽  
Egg Size ◽  
Annual Variation ◽  
Egg Mass ◽  
Annual Variations ◽  
Painted Turtles ◽  
Sources Of Variation ◽  
Clutch Mass

In Algonquin Park, Ontario, body size and clutch characteristics were recorded for 51 female painted turtles (Chrysemyspicta) in 1983, 61 in 1984, and 24 in 1985. Clutch size, clutch mass, and egg width correlated significantly with body size (carapace length) in all 3 years. Egg length and egg mass were significantly related to body size in 1984 and 1985, but not in 1983. There were no significant correlations of egg width or egg mass to clutch size. For a group of the same individuals compared by repeated-measures ANOVA, mean clutch mass and mean egg size, but not mean clutch size, varied significantly among years. Correlation of egg size with body size, lack of correlation between egg size and clutch size, and annual variation in egg size, but not clutch size, all fail to support current versions of optimal egg size theory. Twenty-six females nested in both 1983 and 1984 and 11 females nested in both 1984 and 1985. Fourteen females nested twice in 1 year: six in 1983 and eight in 1984. Between 43 and 73% of adult females nested in a given year and 12–13% nested twice in a single season. These estimates are similar to those reported for other populations of this species. It appears that variations in both clutch size (frequency) and egg size are important sources of variation in reproductive output.

Annual variation in common eider egg size: effects of temperature, clutch size, laying date, and laying sequence

1995 ◽  
Vol 73 (9) ◽  
pp. 1579-1587 ◽  
Author(s):  
Gregory J. Robertson
Keyword(s):  
Clutch Size ◽  
Egg Size ◽  
Annual Variation ◽  
Size Variation ◽  
Egg Laying ◽  
Laying Date ◽  
Somateria Mollissima ◽  
Ambient Temperatures ◽  
Common Eiders ◽  
N 93

Annual variation in volumes of eggs laid by common eiders (Somateria mollissima sedentaria) nesting at La Pérouse Bay, Manitoba (58°43′N, 93°27′W), was studied over 3 years (1991–1993). Temperatures during the egg-laying period were higher in 1991 than in 1992 and 1993. However, the eiders began nesting in 1993 at the same time as in 1991, whereas in 1992 the eiders began laying approximately 2 weeks later. Eiders laid significantly smaller clutches in 1992 than in the other 2 years. Egg size did not correlate with clutch size or laying date in any year. However, eiders laid smaller eggs in 1992 and 1993 than in 1991. In five egg clutches, the pattern of intraclutch egg-size variation was different among years. The last laid eggs of five egg clutches were disproportionately smaller in 1992 and 1993 (cold years) than those laid in 1991. Minimum daily temperatures before the egg-laying period (during rapid yolk development) were positively correlated with egg size. However, this effect was not significant when year and egg sequence were controlled for. Egg-size variation was correlated with the overall ambient temperatures during the laying period, whereas annual clutch-size variation was correlated with laying date, suggesting that the proximate mechanisms affecting clutch and egg size are different.

Environmental, ontogenetic, and genetic variation in egg size of Pied Flycatchers

1993 ◽  
Vol 71 (8) ◽  
pp. 1534-1542 ◽  
Author(s):  
Jaime Potti
Keyword(s):  
Clutch Size ◽  
Egg Size ◽  
Relative Volume ◽  
Laying Date ◽  
Territory Quality ◽  
Trade Off ◽  
Nest Boxes ◽  
Female Condition ◽  
Almost All ◽  
Breeding Seasons

Ontogenetic, genetic, and environmental variation in egg length, breadth, and volume were investigated in the Pied Flycatcher across four breeding seasons in central Spain. Egg length and breadth were poorly correlated and did not vary with laying date. There was an indication of decreasing egg breadth with increasing clutch size that may indicate a trade-off between both variables. Egg size increased with female condition and, independently, with territory quality. Mean egg size decreased with advancing female age, which is perhaps related to the increase of clutch size with age in this species. There were high, significant repeatabilities of almost all egg dimensions, including relative volumes of first and last eggs, among females, both within and between years. Also, nest boxes were repeatable in the relative volume of the last eggs of (different) females laying in them, suggesting an influence of territory quality on relative egg size. Territory quality also had positive influences on some egg measurements that were independent of female condition. Heritability, estimated by mother–daughter regression, was significant only for egg length. These results are discussed in relation to proximate constraints on egg formation, predictions from the brood-survival hypothesis, and a possible trade-off between clutch and egg sizes.

Egg size and clutch size in three species of Nihonotrypaea (Decapoda: Thalassinidea: Callianassidae) from western Kyushu, Japan

2006 ◽  
Vol 86 (1) ◽  
pp. 103-111 ◽  
Author(s):  
K. Kubo ◽  
K. Shimoda ◽  
A. Tamaki
Keyword(s):  
Clutch Size ◽  
Egg Size ◽  
Relative Size ◽  
Size Variation ◽  
Middle Part ◽  
Reproductive Period ◽  
Late Winter ◽  
Estuarine System ◽  
Ariake Sound ◽  
Interspecific Comparisons

Three species of the callianassid genus Nihonotrypaea occur in the Ariake Sound estuarine system, southern Japan; they consist of two tidal-flat species (N. harmandi; N. japonica) and one boulder-beach species (N. petalura), with maximum population densities of 1440, 343, and 12 ind m−2, respectively. Nihonotrypaea harmandi and N. petalura are distributed along the coastline from the outermost part of the sound to the open sea, while N. japonica occurs in the middle part of the sound. Nihonotrypaea japonica has an extended reproductive period from late winter to autumn, while those of the other species are from late spring or summer to autumn. Interspecific comparisons were made for recently laid egg size (as volume) and clutch size (as number of eggs per female). Only in N. japonica was a seasonal egg size variation observed, being significantly larger in winter to spring (mean=0.106 mm3) than in summer (0.080 mm3). By contrast, clutch size was significantly smaller in winter to spring, resulting in nearly the same clutch volume per female (product of the mean egg volume and clutch size) between the seasons. Among the three species, the egg size was ordered as N. japonica (overall mean volume through the seasons=0.092 mm3)>>N. petalura (0.057 mm3)>N. harmandi (0.054 mm3). The clutch size was ordered as N. harmandi>N. petalura≈N. japonica. The clutch volume was ordered as N. japonica≈N. harmandi>N. petalura. The smallest clutch volume value for N. petalura female showed an opposite trend to the relative size of the major cheliped found in a previous study.

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