Monogamy in the European Starling

Behaviour ◽  
1992 ◽  
Vol 120 (3-4) ◽  
pp. 262-285 ◽  
Author(s):  
Innes Cuthill ◽  
Jonathan Wright
Keyword(s):  
Body Size ◽  
Experimental Studies ◽  
Nest Defence ◽  
Female Size ◽  
European Starlings ◽  
Male And Female ◽  
Female Body Size ◽  
Relative Contribution ◽  
Provisioning Rate ◽  
Male Display

AbstractRecent theoretical and experimental studies appear to provide a comprehensive explanation for the evolutionary, and short-term, stability of biparental care in birds. However, much of the intraspecific variation in the absolute and relative contribution by the male and female remains to be explained. Most studies of the natural variation across pairs reveal positive correlations between the level of male and female nest defence or brood provisioning, but some species show negative relations, or between-season variability in the direction of the relationship. This study examines the determinants of male and female provisioning rate in monogamous European starlings (Sturnus vulgaris), in terms of the patterns of male display, pairing patterns, laying phenology and clutch attributes. There was assortative pairing by body size and, controlling for female body size, larger males attracted relatively fecund mates. Males that sang relatively more, controlling for these body size effects, were paired with females that laid earlier. Female nest provisioning rates to experimentally standardized broods were positively correlated with female size, but male provisioning rates were unrelated to either song or any other attributes of themselves or their mates.

scholarly journals Golden Orbweavers Ignore Biological Rules: Phylogenomic and Comparative Analyses Unravel a Complex Evolution of Sexual Size Dimorphism

2018 ◽  
Author(s):  
Matjaž Kuntner ◽  
Chris A. Hamilton ◽  
Cheng Ren-Chung ◽  
Matjaž Gregorič ◽  
Nik Lupše ◽  
...  
Keyword(s):  
Body Size ◽  
Female Body ◽  
Sexual Size Dimorphism ◽  
Female Size ◽  
Male And Female ◽  
Size Dimorphism ◽  
Female Body Size ◽  
Size Evolution ◽  
Web Size ◽  
Cope’S Rule

AbstractInstances of sexual size dimorphism (SSD) provide the context for rigorous tests of biological rules of size evolution, such as Cope’s Rule (phyletic size increase), Rensch’s Rule (allometric patterns of male and female size), as well as male and female body size optima. In certain spider groups, such as the golden orbweavers (Nephilidae), extreme female-biased SSD (eSSD, female:male body length ≥ 2) is the norm. Nephilid genera construct webs of exaggerated proportions which can be aerial, arboricolous, or intermediate (hybrid). First, we established the backbone phylogeny of Nephilidae using 367 Anchored Hybrid Enrichment (AHE) markers, then combined these data with classical markers for a reference species-level phylogeny. Second, we used the phylogeny to test Cope and Rensch’s Rules, sex specific size optima, and the coevolution of web size, type, and features with female and male body size and their ratio, SSD. Male, but not female, size increases significantly over time, and refutes Cope’s Rule. Allometric analyses reject the converse, Rensch’s Rule. Male and female body sizes are uncorrelated. Female size evolution is random, but males evolve towards an optimum size (3.2–4.9 mm). Overall, female body size correlates positively with absolute web size. However, intermediate sized females build the largest webs (of the hybrid type), giant female Nephila and Trichonephila build smaller webs (of the aerial type), and the smallest females build the smallest webs (of the arboricolous type). We propose taxonomic changes based on the criteria of clade age, monophyly and exclusivity, classification information content, diagnosability, and arachnological community practice. We resurrect the family Nephilidae Simon 1894 that contains Clitaetra Simon 1889, the Cretaceous Geratonephila Poinar & Buckley 2012, Herennia Thorell 1877, Indoetra Kuntner 2006, new rank, Nephila Leach 1815, Nephilengys L. Koch 1872, Nephilingis Kuntner 2013, and Trichonephila Dahl 1911, new rank. We propose the new clade Orbipurae to contain Araneidae Clerck 1757, Phonognathidae Simon 1894, new rank, and Nephilidae. Nephilid female gigantism is a phylogenetically-ancient phenotype (over 100 ma), as is eSSD, though their magnitudes vary by lineage and, to some extent, biogeographically.

Sex and size affecting time allocations for activities in Uca annulipes (H. Milne Edwards, 1837)

Crustaceana ◽  
2016 ◽  
Vol 89 (6-7) ◽  
pp. 759-773 ◽  
Author(s):  
Fahmida Wazed Tina ◽  
Mullica Jaroensutasinee ◽  
Krisanadej Jaroensutasinee
Keyword(s):  
Body Size ◽  
Female Body ◽  
Feeding Rate ◽  
Small Male ◽  
Fiddler Crabs ◽  
Male And Female ◽  
Negatively Associated ◽  
Female Body Size ◽  
Uca Annulipes

We investigated the amount of time that large and small, male and female fiddler crabsUca annulipes(H. Milne Edwards, 1837) spent on feeding, walking, standing, grooming, burrowing, inside burrows, fighting, and courtship waving. We video-recorded the activities of 45 males (22 small and 23 large), and 39 females (19 small and 20 large) each for 5 min, and calculated the percentage of time spent on each activity/crab. Our results showed that both sexes spent more time on feeding than on other activities. Males spent more time on building burrows, walking, and grooming than females, and females spent more time inside burrows than males. Smaller males spent more time on feeding, and less time on building burrows and on waving than larger ones. There were no relations between female body size and activities. Feeding rate/feeding claw was higher in males than in females, and crab body size was negatively associated with feeding rate/min.

Differences Between Male and Female Preferences for Female Body Size

1990 ◽  
Vol 25 (3) ◽  
pp. 314-317 ◽  
Author(s):  
Gail F. Huon ◽  
Sue E. Morris ◽  
Laurence B. Brown
Keyword(s):  
Body Size ◽  
Female Body ◽  
Male And Female ◽  
Female Body Size ◽  
Female Preferences

Egg burial depth by sockeye salmon (Oncorhynchus nerka): implications for survival of embryos and natural selection on female body size

1999 ◽  
Vol 77 (5) ◽  
pp. 836-841 ◽  
Author(s):  
Ryan P Steen ◽  
Thomas P Quinn
Keyword(s):  
Body Size ◽  
Female Body ◽  
Sockeye Salmon ◽  
Oncorhynchus Nerka ◽  
Female Size ◽  
Burial Depth ◽  
Female Body Size ◽  
Substrate Level ◽  
The Relationship ◽  
Stream Bed

We studied the relationship between female sockeye salmon (Oncorhynchus nerka) body size and egg burial depth in a small Alaskan stream to better understand the ways in which stream-bed scour or digging by other females might destroy embryos. Two different measurements of egg burial depth were taken: depth from the original stream-bed surface to the top of the egg pocket and depth from the disturbed substrate directly above the egg pocket to the top of the egg pocket. The former may represent the depth to which stream-bed scouring would have to go to reach the eggs, but the latter represents the depth to which a second female would have to dig to disturb the egg pocket. Larger females buried their eggs deeper, relative to the original substrate level, than smaller females. This suggests that streams with frequent scour events would select for larger females. However, mean depth from the disturbed substrate level was significantly shallower than mean depth from the original stream-bed level, suggesting that even the smallest females could dig deep enough to disturb the egg pockets of the largest females. Finally, the egg burial depth - fish size relationship that we observed was compared with published data on other salmonid species, revealing considerable variation but a clear positive relationship between female size and burial depth. Because embryonic survival is affected by scour and nest disturbance, and because changes in fish body size, density, and flow regime can affect the vulnerability of embryos to such mortality, we recommend further, standardized measurements of the relationship between egg burial depth and female body size.

EXPERIMENTAL EVIDENCE FOR THE COST OF POLYGYNY IN THE RED-WINGED BLACKBIRD AGELAIUS PHOENICEUS

Behaviour ◽  
2000 ◽  
Vol 137 (9) ◽  
pp. 1153-1173 ◽  
Author(s):  
Stanislav Pribil
Keyword(s):  
Body Size ◽  
Reproductive Success ◽  
Experimental Studies ◽  
Agelaius Phoeniceus ◽  
Lower Survival ◽  
Harem Size ◽  
Fledgling Survival ◽  
Provisioning Rate ◽  
The Difference ◽  
The Cost

AbstractI examined the effect of harem size on female reproductive success in the red - winged blackbird (Agelaius phoeniceus) in Ontario while controlling for the confounding effects of territory and male quality. Male territories were matched by their quality and harem sizes were manipulated by selective removal of females. The removals created monogamous and bigamous harems. Bigamous females fledged significantly fewer young than monogamous females, mainly due to higher predation on their nests. Young of the bigamous females were fed less frequently than young of the monogamous females (mainly due to reduced male assistance), but the difference was not significant. There was a positive relationship between parental provisioning rate and nestling body size. Young of the bigamous females fledged at smaller body size than young of the monogamous females. Because fledgling body size is related to post - fledgling survival, young of the bigamous females presumably experienced lower survival than young of the monogamous females. The lower number of fledglings, combined with their lower survival, suggests that the bigamous females produced fewer descendants than the monogamous females. I conclude that polygyny is costly to females in this population of the red - winged blackbird. Previous experimental studies demonstrated that females in this population prefer to settle with unmated males rather than already - mated males. In light of the present findings, the preferences appear adaptive, as they reduce the cost of polygyny. In Pennsylvania, Searcy (1988) reported that females settle independently of harem size and that harem size has no effect on their reproductive success. A comparison of the Ontario and Pennsylvania populations suggest that there are geographic differences in the effect of harem size on both female preferences and reproductive success.

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.

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