Open Access. Powered by Scholars. Published by Universities.®
- Institution
- Publication
- Publication Type
Articles 1 - 8 of 8
Full-Text Articles in Life Sciences
Reproductive Traits And Change In Body Shape Of Neonates In The Oak Forest Skink, Plestiodon Lynxe, Manuel Feria-Ortiz, Uri Omar García-Vázquez, Carlos Joaquín Pavón-Vázquez, Adrián Nieto-Montes De Oca
Reproductive Traits And Change In Body Shape Of Neonates In The Oak Forest Skink, Plestiodon Lynxe, Manuel Feria-Ortiz, Uri Omar García-Vázquez, Carlos Joaquín Pavón-Vázquez, Adrián Nieto-Montes De Oca
Publications and Research
Reproductive traits are critically important for understanding how organisms adapt to their respective environments. In this study, we provide information on relative litter mass (RLM) and other litter and neonate related characters of nine female Plestiodon lynxe captured in the field. We also recorded seven body dimensions in 16 neonates and 15 two-month juveniles, and on the basis of these dimensions we compared the body shape of these two age classes to detect changes in the proportions of body parts. The average litter size (4.55) is larger than that found in other viviparous species of Plestiodon, but smaller than …
Influence Of Testosterone On Male-Male Competition In The Red-Sided Garter Snake, Thamnophis Sirtalis Parietalis, Isabella M. G. Bukovich
Influence Of Testosterone On Male-Male Competition In The Red-Sided Garter Snake, Thamnophis Sirtalis Parietalis, Isabella M. G. Bukovich
Senior Honors Projects, 2020-current
Female mimicry in the red-sided garter snake, Thamnophis sirtalis parietalis, is described in several well-studied evolutionary advantages, but an aspect that remains elusive is how reproductive traits are linked to the 3-fold higher circulating androgens in males with this phenotype. In this study, we implanted male garter snakes (n=15 per group) with either a blank implant (SHAM; control) or a T implant, the latter simulating the female mimic phenotype. Following simulated low-temperature dormancy, males were scored for courtship intensity over three days of behavioral trials with females housed in the same facility. Males were sacrificed, and sperm were collected …
Practical Problems And Moral Discourses: An Ethnography Of Breastfeeding, Tara Ann Gallagher
Practical Problems And Moral Discourses: An Ethnography Of Breastfeeding, Tara Ann Gallagher
Theses and Dissertations
Universal and bioactive, breastfeeding is a burgeoning biocultural topic because it incorporates biological and social determinants of human behavior. The topic has amassed media attention framed as part of a bigger imagining of motherhood as an idealized state directed at the female body’s performance. This paper questions media and public policy’s role in the dissemination of culture and the symbolic value of breastmilk. This study examines breastfeeding discourses through the lens of an American, mostly white, Midwestern middle-class social structure. Using participant observation data of two postpartum support groups and semi-structured interviews with six primiparous mothers, my data suggests that …
Do Female Western Mosquitofish, Gambusia Affinis, Prefer Ornaments That Males Lack?, Scott L. Kight, Olga Degtyareva, Heather Fackelman, Ariel Casner
Do Female Western Mosquitofish, Gambusia Affinis, Prefer Ornaments That Males Lack?, Scott L. Kight, Olga Degtyareva, Heather Fackelman, Ariel Casner
Department of Biology Faculty Scholarship and Creative Works
Some species in the family Poeciliidae are known for extravagant male ornaments and courtship behavior (e.g. guppies), but the majority of poeciliids are characterized by coercive male copulation attempts that seem to circumvent female choice. In some lineages with male ornaments, female sensory bias may have preceded the evolution of corresponding male signals. We examined female preferences for colorful ornaments in Western mosquitofish, Gambusia affinis, in which males lack ornamentation and reproduce primarily through coercive mating attempts. We found that females exhibited a positional affinity for males that were artificially ornamented with blue coloration over males that had been …
The Reproductive Ecology Of The Timber Rattlesnake, Crotalus Horridus, In Northwestern Arkansas: Interactions Between Environment, Steroid Hormones, And Life History, Craig Michael Lind
The Reproductive Ecology Of The Timber Rattlesnake, Crotalus Horridus, In Northwestern Arkansas: Interactions Between Environment, Steroid Hormones, And Life History, Craig Michael Lind
Graduate Theses and Dissertations
In this dissertation I examined the relationship between individual energetic status, hormone production, and life history trait expression in field-active Timber Rattlesnakes, Crotalus horridus. In chapter one I reviewed what is known regarding these relationships in snakes and defined major research goals. In chapter two I described the seasonal profile of testosterone (T) and corticosterone (CORT) in relation to the breeding season and to individual energetic status in males. Results showed that the seasonal pattern of T production in C. horridus was different than other pit viper species with similar mating patterns. Testosterone was elevated in the months leading up …
Seasonality Of Conceptions Under Varying Conditions In A Rhesus Macaque Breeding Colony, Ryan Disney Patrick Dunk
Seasonality Of Conceptions Under Varying Conditions In A Rhesus Macaque Breeding Colony, Ryan Disney Patrick Dunk
Theses and Dissertations
Rhesus macaques (Macaca mulatta) are well documented as seasonal breeders. Despite this, little is known about what factors influence seasonal reproduction in rhesus. It has been proposed that rhesus are "relaxed income breeders" (Brockman and van Schaik, 2005), which means they respond to changes in photoperiod but endogenous cues can allow deviations from photoperiod-timed seasonality. This study presents the results of a natural experiment on the influence of different housing conditions (featuring different levels of environmental exposure) on the seasonal pattern of reproduction in rhesus. Once the number of attempts was controlled for, rhesus did not exhibit a seasonal distribution …
A Sex Difference In Seasonal Timing Of Birth In A Livebearing Fish, Eric T. Schultz
A Sex Difference In Seasonal Timing Of Birth In A Livebearing Fish, Eric T. Schultz
EEB Articles
Sex differences in seasonal timing include differences in hatch- or birth-date distribution and differences in the timing of migration or maturation such as protandrous arrival timing (PAT), which is early male arrival at breeding sites. I describe a novel form of protandrous arrival timing, as a sex difference in birth-date distribution in a live-bearing fish (Dwarf Perch, Micrometrus minimus). In this species, birth coincides with arrival at breeding sites because newborn males are sexually active. A series of samples of pregnant females and young of year was collected in Tomales Bay, CA. I analyzed the daily age record in otoliths …
Decreased Reproductive Investment Of Female Threespine Stickleback Gasterosteus Aculeatus Infected With The Cestode Schistocephalus Solidus: Parasite Adaptation, Host Adaptation, Or Side Effect?, Eric T. Schultz, Michelle Topper, David C. Heins
Decreased Reproductive Investment Of Female Threespine Stickleback Gasterosteus Aculeatus Infected With The Cestode Schistocephalus Solidus: Parasite Adaptation, Host Adaptation, Or Side Effect?, Eric T. Schultz, Michelle Topper, David C. Heins
EEB Articles
Parasitic infections may cause alterations in host life history, including changes in reproductive investment (absolute amount of energy allocated to reproduction) and reproductive effort (proportion of available energy allocated to reproduction). Such changes in host life history may reflect: 1) a parasite tactic: the parasite adaptively manipulates energy flow within the host so that the host is induced to make a reduction in reproductive effort and reproductive investment, making more energy available to the parasite; 2) no tactic: there is no change in host reproductive effort and reproductive investment simply decreases as a side effect of the parasite depleting host …