Life history and reproductive ecology of White's skink, Egernia whitii

2005 ◽  
Vol 53 (6) ◽  
pp. 353 ◽  
Author(s):  
DG Chapple
Keyword(s):  
Life History ◽  
Litter Size ◽  
Reproductive Ecology ◽  
Climatic Conditions ◽  
Colour Pattern ◽  
Offspring Size ◽  
Adult Sex Ratio ◽  
Pattern Polymorphism ◽  
Comparison Of The Results ◽  
Colour Morphs

The life history and reproductive ecology of White’s skink, Egernia whitii, was examined in a population in the Australian Capital Territory using both field and genetic studies. Colour pattern polymorphism was evident within the population, with both patterned and plain-back morphs present. Lizards typically took 3 years to reach sexual maturity, with the size at maturity being ~75 mm snout–vent length (SVL) in both sexes. There was an even overall adult sex ratio, although a slight female-bias was evident in plain-back individuals. Sexual dimorphism was evident, with males having longer and wider heads, and females having larger body size. Females generally bred annually, with mating occurring in September–October and parturition in late January–February, although the litter was produced over several days (2–10 days, mean 4 days). Litter size ranged from one to four (mean of 2.5). There was a significant relationship between maternal SVL and both litter size and relative clutch mass, but these trends were not consistent between colour morphs. An inverse relationship between litter size and offspring size (SVL and mass) was found. Comparison of the results with previous investigations of E. whitii indicates substantial geographic variation in life-history traits that is presumably associated with latitudinal variation in climatic conditions.

scholarly journals Trade-off between offspring mass and number: the lightest offspring bear the costs

2020 ◽  
Vol 16 (2) ◽  
pp. 20190707
Author(s):  
Joanie Van de Walle ◽  
Andreas Zedrosser ◽  
Jon E. Swenson ◽  
Fanie Pelletier
Keyword(s):  
Life History ◽  
Litter Size ◽  
Phenotypic Variation ◽  
Reproductive Strategy ◽  
Life History Theory ◽  
Brown Bear ◽  
Offspring Size ◽  
Trade Off ◽  
The Relationship

Life-history theory predicts a trade-off between offspring size and number. However, the role of intra-litter phenotypic variation in shaping this trade-off is often disregarded. We compared the strength of the relationship between litter size and mass from the perspective of the lightest and the heaviest yearling offspring in 110 brown bear litters in Sweden. We showed that the mass of the lightest yearlings decreased with increasing litter size, but that the mass of the heaviest yearling remained stable, regardless of litter size. Consistent with a conservative reproductive strategy, our results suggest that mothers maintained a stable investment in a fraction of the litter, while transferring the costs of larger litter size to the remaining offspring. Ignoring intra-litter phenotypic variation may obscure our ability to detect a trade-off between offspring size and number.

scholarly journals Evolution and maintenance of colour pattern polymorphism in Liopholis (Squamata:Scincidae)

2008 ◽  
Vol 56 (2) ◽  
pp. 103 ◽  
Author(s):  
David G. Chapple ◽  
Mark N. Hutchinson ◽  
Brad Maryan ◽  
Mike Plivelich ◽  
Jennifer A. Moore ◽  
...  
Keyword(s):  
Relative Abundance ◽  
Arid Zone ◽  
Colour Pattern ◽  
Future Studies ◽  
Alpine Regions ◽  
Subsequent Loss ◽  
Pattern Polymorphism ◽  
Colour Morphs ◽  
Species Being ◽  
Latitudinal Band

We examined the evolution and maintenance of colour pattern polymorphism in an Australian lineage of scincid lizards, the genus Liopholis. Liopholis comprises 11 species, with representatives in both the temperate zone and arid zone. Specimens from all major Australian museums were examined to characterise colour pattern polymorphism within Liopholis, and investigate geographic variation in the relative abundance of morphs within polymorphic species. We used a previously published phylogeny for Liopholis to investigate the evolution and maintenance of colour pattern polymorphism within the group. Five species were found to exhibit colour pattern polymorphism (L. margaretae margaretae Storr, L. m. personata Storr, L. montana Donnellan et al., L. multiscutata Mitchell & Behrndt, L. pulchra Werner, L. whitii Lacépède), with six species being monomorphic (L. guthega Donnellan et al., L. inornata Rosén, L. kintorei Stirling & Zietz, L. modesta Storr, L. slateri Storr, L. striata Sternfeld). Three colour morphs occur in L. whitii, with the relative abundance of each varying significantly among latitudes. The patterned morph is most common, while the incidence of the plain-back morph decreases at latitudes higher than 35°S. The L. whitii patternless morph occurs only within a narrow latitudinal band (34–38°S). In L. multiscutata, the relative abundance of the patterned (~89–93%) and patternless morph (~7–11%) is consistent across regions, except for the Nullarbor Plain region where the patternless morph is more common (~39%). Our analyses suggest a single origin of colour pattern polymorphism in Liopholis, followed by the subsequent loss of polymorphism on four occasions. The secondary loss of polymorphism might be associated with climate or habitat, possibly as the result of shifts into the arid zone or alpine regions of Australia. This study provides the necessary framework for future studies of colour pattern polymorphism in Liopholis.

Reproductive Ecology of The Allied Rock-wallaby, Petrogale assimilis.

1996 ◽  
Vol 19 (2) ◽  
pp. 209
Author(s):  
R. Delaney
Keyword(s):  
Life History ◽  
Sex Ratio ◽  
Sexual Maturity ◽  
Post Partum ◽  
Reproductive Ecology ◽  
Oestrous Cycle ◽  
Embryonic Diapause ◽  
Minimum Age

Petrogale assimilis has a typical life history and reproductive ecology for a macropodid of its size. Both sexes are capable of reproducing continuously; gestation is about the same length as the oestrous cycle (approximately one month); a single young is born and, a post-partum oestrus and embryonic diapause probably occurs. The sex ratio of young is unbiased. Pouch young remain permanently attached to the teat until 110 - 143 days (n=11). Permanent exit from the pouch occurs at 180 - 231 days (mean=201 days, n=25), and weaning occurs between 267 - 387 days (n=5). Sexual maturity occurs at a minimum age of 17.5 months in females and 23 months in males.

Barriers to salmon migration impact body condition, offspring size, and life history variation in an avian consumer

Ecography ◽  
2016 ◽  
Vol 39 (11) ◽  
pp. 1056-1065 ◽  
Author(s):  
Christopher M. Tonra ◽  
Kimberly Sager-Fradkin ◽  
Peter P. Marra
Keyword(s):  
Life History ◽  
Body Condition ◽  
Offspring Size ◽  
Life History Variation

Reproductive Ecology and Life History of Female Sonoran Desert Tortoises (Gopherus morafkai)

2018 ◽  
Vol 32 (1) ◽  
pp. 34-50 ◽  
Author(s):  
Roy C. Averill-Murray ◽  
Terry E. Christopher ◽  
Brian T. Henen
Keyword(s):  
Life History ◽  
Sonoran Desert ◽  
Reproductive Ecology ◽  
Gopherus Morafkai ◽  
History Of

scholarly journals Codling-moth Investigations of the State Entomologist's Office

1922 ◽  
Vol 14 (1-10) ◽  
pp. 219-289 ◽  
Author(s):  
P. A. Glenn
Keyword(s):  
Life History ◽  
Codling Moth ◽  
Climatic Conditions ◽  
The State ◽  
Accurate Data ◽  
Rate Of Development ◽  
History Of ◽  
Seasonal History

To secure accurate data in regard to the life history and the seasonal history of the codling-moth in Illinois, and the relation of climatic conditions to the rate of development and the time of appearance of the various stages of the insect, an investigation was begun in the spring of 1915 under the direction of Doctor S. A. Forbes, then State Entomologist.

Clutch Mass, Offspring Mass, and Clutch Size: Body Mass Scaling and Taxonomic and Environmental Variation

2018 ◽  
pp. 68-97
Author(s):  
Douglas S. Glazier
Keyword(s):  
Life History ◽  
Body Size ◽  
Clutch Size ◽  
Body Mass ◽  
Life History Evolution ◽  
Offspring Size ◽  
Egg Mass ◽  
Mass Scaling ◽  
Scaling Relationships ◽  
Clutch Mass

In this chapter, I show how clutch mass, offspring (egg) mass, and clutch size relate to body mass among species of branchiopod, maxillipod, and malacostracan crustaceans, as well as how these important life history traits vary among major taxa and environments independently of body size. Clutch mass relates strongly and nearly isometrically to body mass, probably because of physical volumetric constraints. By contrast, egg mass and clutch size relate more weakly and curvilinearly to body mass and vary in inverse proportion to one another, thus indicating a fundamental trade-off, which occurs within many crustacean taxa as well. In general, offspring (egg) size and number and their relationships to body mass appear to be more ecologically sensitive and evolutionarily malleable than clutch mass. The body mass scaling relationships of egg mass and clutch size show much more taxonomic and ecological variation (log-log scaling slopes varying from near 0 to almost 1 among major taxa) than do those for clutch mass, a pattern also observed in other animal taxa. The curvilinear body mass scaling relationships of egg mass and number also suggest a significant, size-related shift in how natural selection affects offspring versus maternal fitness. As body size increases, selection apparently predominantly favors increases in offspring size and fitness up to an asymptote, beyond which increases in offspring number and thus maternal fitness are preferentially favored. Crustaceans not only offer excellent opportunities for furthering our general understanding of life history evolution, but also their ecological and economic importance warrants further study of the various factors affecting their reproductive success.

scholarly journals Effects of life history stage and climatic conditions on fecal egg counts in plains zebras (Equus quagga) in the Serengeti National Park

2020 ◽  
Vol 119 (10) ◽  
pp. 3401-3413
Author(s):  
Peter A. Seeber ◽  
Tetiana A. Kuzmina ◽  
Alex D. Greenwood ◽  
Marion L. East
Keyword(s):  
Life History ◽  
Environmental Conditions ◽  
National Park ◽  
Climatic Conditions ◽  
Life History Stage ◽  
Gastrointestinal Parasite ◽  
Serengeti Ecosystem ◽  
Life History Stages ◽  
Lactating Females ◽  
Host Life

Abstract In wildlife, endoparasite burden can be affected by host life history stage, environmental conditions, host abundance, and parasite co-infections. We tested the effects of these factors on gastrointestinal parasite infection in plains zebras (Equus quagga) in the Serengeti ecosystem, Tanzania, using fecal egg counts of two nematode families (Strongylidae and Ascarididae) and the presence/absence of cestode (Anoplocephalidae) eggs. We predicted higher egg counts of Strongylidae and Ascarididae, and increased likelihood of Anoplocephalidae infection in individuals (1) during energetically costly life history stages when resource allocation to immune processes may decrease and in young zebras after weaning because of increased uptake of infective stages with forage, (2) when climatic conditions facilitate survival of infective stages, (3) when large zebra aggregations increase forage contamination with infective stages, and (4) in individuals co-infected with more than one parasite group as this may indicate reduced immune competence. Strongylidae egg counts were higher, and the occurrence of Anoplocephalidae eggs was more likely in bachelors than in band stallions, whereas Ascarididae egg counts were higher in band stallions. Strongylidae and Ascarididae egg counts were not increased in lactating females. Strongylidae egg counts were higher in subadults than in foals. Regardless of sex and age, Ascarididae infections were more likely under wet conditions. Co-infections did not affect Strongylidae egg counts. Ascarididae egg counts in adult females were higher when individuals were co-infected with Anoplocephalidae. We present evidence that parasite burdens in plains zebras are affected by life history stage, environmental conditions, and co-infection.

scholarly journals Association of gdf9 Gene Polymorphisms With Litter Size in Indigenous Sheep of Bangladesh

2020 ◽  
Vol 7 (2) ◽  
pp. 283-292
Author(s):  
Faruk Hossain ◽  
Sharmin Akter Suma ◽  
Mohammad Shamsul Alam Bhuiyan
Keyword(s):  
Gene Polymorphism ◽  
Litter Size ◽  
Gene Polymorphisms ◽  
Climatic Conditions ◽  
Animal Protein ◽  
Selection Program ◽  
Indigenous Sheep ◽  
Gdf9 Gene

Sheep in Bangladesh are well known as efficient users of low quality roughages, welladapted to hot and humid agro-climatic conditions, capable of bi-annual lambing withmultiple births and resistant to common prevalent diseases. They play an important role inthe supply of animal protein. Present study aimed to investigate possible association ofGDF9 gene polymorphisms with litter size. A total of 126 DNA samples extracted from theblood of indigenous sheep from 5 locations namely Tangail, Noakhali, Naogaon,Gaibandha and Satkhira with known litter size were used to study the association ofGDF9 polymorphism by PCR based RFLP method. Two polymorphic regions of GDF9(FecG1 and FecG8) were amplified by PCR, digested with respective restriction enzymesand 126 sheep were genotyped. Current study revealed that genotype and allelefrequency for FecG1 varied among the sheep from different locations. The genotype (GG,AG, AA) frequency were 51.59%, 45.24% and 3.17% and the allele (G and A) frequenciesin the overall population were 74.21% and 25.79%, respectively. There was a significantassociation of FecG1 of GDF9 gene polymorphism with litter size. The homozygous GGgenotype had the lowest litter size (1.59±0.09; n=65) and homozygous AA genotype hadthe highest litter size (2.00±0.41; n=4). No genotypic variations were found for FecG8.Findings of this study specially the polymorphism of FecG1 together with genotyping ofsome sheep could be utilized in the selection program to increase the lamb productionpotentiality of indigenous sheep of Bangladesh. Res. Agric., Livest. Fish.7(2): 283-292,  August 2020

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