Site fidelity of Weddell seals: the effects of sex and age

2007 ◽  
Vol 19 (2) ◽  
pp. 149-155 ◽  
Author(s):  
Michael F. Cameron ◽  
Donald B. Siniff ◽  
Kelly M. Proffitt ◽  
Robert A. Garrott
Keyword(s):  
Life History ◽  
Site Fidelity ◽  
Life History Strategy ◽  
Reproductive Rate ◽  
Weddell Seals ◽  
Adult Females ◽  
Males And Females ◽  
A Site ◽  
Traditional Breeding

AbstractSite fidelity is believed to be an important life history strategy for Weddell seals (Leptonychotes weddellii), that return to traditional breeding colonies each spring. We examined four hypotheses concerning their fidelity to these colonies: 1) fidelity is stronger to natal sites (natal fidelity) than to other sites, 2) females exhibit greater site fidelity than males, 3) site fidelity for both sexes increases with age, 4) site fidelity in adult females is related to their reproductive status and their total number of offspring. Analysis of a long-term tagging database from McMurdo Sound did not support hypotheses 1 and 2. Although animals did express fidelity to specific sites over their lifetime (χ2 tests, P < 0.05), fidelity to natal colonies was lower than to other sites (χ2 test, P < 0.05). There were no differences in site fidelity between males and females (χ2 tests, P > 0.05). Hypothesis 3 was supported. Since the probability of a returning seal occupying the same colony as the previous year increased with age among both sexes to about age 12. Finally, in support of hypothesis 4, females with a higher degree of site fidelity were more likely to both have a higher reproductive rate and return to a site where they have previously given birth.

Reintroduction of the greater bilby, Macrotis lagotis (Reid) (Marsupialia : Thylacomyidae), to northern South Australia: survival, ecology and notes on reintroduction protocols

2003 ◽  
Vol 30 (1) ◽  
pp. 15 ◽  
Author(s):  
K. E. Moseby ◽  
E. O'Donnell
Keyword(s):  
Site Fidelity ◽  
South Australia ◽  
Home Range Size ◽  
Home Ranges ◽  
Radio Tracking ◽  
Significant Preference ◽  
Adult Females ◽  
Males And Females ◽  
Food Reserves

Nine bilbies were reintroduced to a 14-km2 reserve free of rabbits, cats and foxes in South Australia in April 2000. The survival, growth and ecology of the population were studied for 17 months after release by means of radio-tracking and trapping. Reproduction was continuous over the study period, with juveniles successfully recruited into the population. Home-range size of female bilbies averaged 0.18 km2 and was significantly smaller than home ranges of males, which averaged 3.16 km2. Wild-born subadults had smaller home ranges than adults. While male home ranges, and male and female home ranges overlapped considerably, females appeared to maintain areas discrete from other adult females. Bilbies showed a significant preference for dune habitat. As swale habitat appears too hard for burrow construction and males moved greater distances from diurnal burrows than females, males are likely to access food reserves that are under-used by females. Both males and females reused at least 30% of their burrows, and females displayed long-term site fidelity. The release was considered successful and suggests that despite historical damage from rabbits and stock, bilbies are able to successfully recolonise parts of their former range in arid South Australia once rabbits, cats and foxes are removed.

scholarly journals Live Fast, Die Young, and Sleep Later: Life History Strategy and Human Sleep Behavior

2020 ◽  
Author(s):  
Vahe Dishakjian ◽  
Daniel M T Fessler ◽  
Adam Maxwell Sparks
Keyword(s):  
Life History ◽  
Individual Differences ◽  
Sleep Duration ◽  
Sleep Onset ◽  
Life History Strategy ◽  
The Body ◽  
Equation Modeling ◽  
Sleep Onset Latency ◽  
Sleep Behaviors

Abstract Background and objectives Life History Theory (LHT) describes trade-offs that organisms make with regard to three investment pathways: growth, maintenance, and reproduction. In light of the reparative functions of sleep, we examine sleep behaviors and corresponding attitudes as proximate manifestations of an individual’s underlying relative prioritization of short-term reproduction versus long-term maintenance. Methodology We collected survey data from 568 participants across two online studies having different participant pools. We use a mixture of segmented and hierarchical regression models, structural equation modeling, and machine learning to infer relationships between sleep duration/quality, attitudes about sleep, and biodemographic/psychometric measures of life history strategy (LHS). Results An age-mediated U- or V-shaped relationship appears when LHS is plotted against habitual sleep duration, with the fastest strategies occupying the sections of the curve with the highest mortality risk: &lt; 6.5 hours (short sleep) and &gt; 8.5 hours (long sleep). LH “fastness” is associated with increased sleepiness and worse overall sleep quality: delayed sleep onset latency, more wakefulness after sleep onset, higher sleep-wake instability, and greater sleep duration variability. Hedonic valuations of sleep may mediate the effects of LHS on certain sleep parameters. Conclusions and implications The costs of deprioritizing maintenance can be parameterized in the domain of sleep, where “life history fastness” corresponds with sleep patterns associated with greater senescence and mortality. Individual differences in sleep having significant health implications can thus be understood as components of lifelong trajectories likely stemming from calibration to developmental circumstances. Relatedly, hedonic valuations of sleep may constitute useful avenues for non-pharmacological management of chronic sleep disorders. LAY Summary Sleep is essential because it allows the body to repair and maintain itself. But time spent sleeping is time that cannot be spent doing other things. People differ in how much they prioritize immediate rewards, including sociosexual opportunities, versus long-term goals. In this research, we show that individual differences in sleep behaviors, and attitudes toward sleep, correspond with psychological and behavioral differences reflecting such differing priorities. Orientation toward sleep can thus be understood as part of the overall lifetime strategies that people pursue.

Variation in Women’s Mate Preferences Over the Development of a Monogamous Relationship Corresponds with Changes in Men’s Life History Strategy (Author's Accepted Version)

2019 ◽  
Author(s):  
Rebecca Owens ◽  
Helen Driscoll ◽  
Daniel Farrelly
Keyword(s):  
Life History ◽  
Life History Theory ◽  
Life History Strategy ◽  
Mate Preferences ◽  
Mating Strategies ◽  
Mating Effort ◽  
Monogamous Relationship ◽  
Parenting Effort ◽  
The Relationship

Much research has examined how men’s mating strategies change over the development of a relationship consistent with predictions from Life History Theory. Specifically, research shows both physiological and behavioural indicators of mating effort decrease once men are mated, and further once they become fathers, unless they remain engaged in mating effort. This switch from mating to parenting effort is sexually selected, and therefore the corresponding shifts in women should be examined, though to date, women’s short- or long-term mate preferences have been studied as separate entities rather than as a transition from short- to long- term. We examined how women’s mate preferences changed over the development of a relationship, to see if they varied consistently with what is known about variation in men’s mating effort. Vignettes detailed four key milestones in the development of a relationship and women rated the importance of the man at each stage displaying indicators of mating or parenting effort. Women increasingly prioritised indicators of parenting effort in men as the relationship developed, consistent with what is known about men’s reduction in mating effort in favour of parenting effort over the development of a relationship. The results support predictions from Life History Theory and highlight the interacting mutually reinforcing nature of sexually selected behaviours.

scholarly journals NATURAL HISTORY OF DEKAY’S BROWNSNAKE, STORERIA DEKAYI (HOLBROOK, 1836), AT A SITE IN NORTHWESTERN PENNSYLVANIA

2014 ◽  
pp. 28-39
Author(s):  
Brian S. Gray
Keyword(s):  
Population Structure ◽  
Site Fidelity ◽  
Additional Data ◽  
Tail Length ◽  
Adult Males ◽  
Morphometric Data ◽  
Erie County ◽  
Adult Females ◽  
History Of ◽  
A Site

A population of Dekay’s Brownsnake, Storeria dekayi was studied using mark-recapture techniques in Erie County, Pennsylvania, USA during the spring, summer and autumn of 2012. Morphometric data were similar to that reported for the species, with adult females averaging larger and more massive than adult males. However, sexual dimorphism in snout-vent length (SVL) and total length (TL) was not significantly different (P>0.05) in juveniles, although relative tail length (tl/TL) was dimorphic. Relative tail length in both juveniles and adults was greater in males (tl/TL = 0.22-0.27) than females (tl/TL = 0.18-0.23). Storeria dekayi were active from 21 March through 22 October, and displayed a bimodal activity pattern, with peaks in April and August. Using the Schnabel and the Schumacher-Eschmeyer methods, population size was estimated to be 122 ± 19 and 130 ± 35 individuals, respectively. Density was estimated to be 244 and 260 snakes/ha, and biomass 1.60 and 1.71 kg/ha. Additional data regarding population structure, mortality, diet, reproduction, body temperature, movements and site fidelity are also presented.

scholarly journals A complex interplay between balancing selection and introgression maintains a genus-wide alternative life-history strategy.

2021 ◽  
Author(s):  
kalle tunström ◽  
Alyssa Woronik ◽  
Joseph J Hanly ◽  
Pasi Rastas ◽  
Anton Chichvarkhin ◽  
...  
Keyword(s):  
Life History ◽  
Life Histories ◽  
Balancing Selection ◽  
Genetic Locus ◽  
Regulatory Region ◽  
Life History Strategy ◽  
Life History Strategies ◽  
Pigment Synthesis ◽  
Evolutionary Forces

Alternative life-history strategies (ALHS) are genetic polymorphisms generating phenotypes differing in life histories that generally arise due to metabolic resource allocation tradeoffs. Althouigh ALHS are often be limited to a single sex or populations of a species, they can, in rare cases, be found among several species across a genus. In the butterfly genus Colias, at least a third of the species have a female limited ALHS called Alba. While many females develop brightly pigmented wings, Alba females reallocate nitrogen resources used in pigment synthesis to reproductive development, producing white-winged, more fecund females. Whether this ALHS evolved once or many times, and whether it has moved among species via introgression or been maintained via long-term balancing selection, has not been established. Answering these questions presents an opportunity to investigate the genetic basis and evolutionary forces acting upon ALHS, which have rarely been studied at a genus level. Here we identify the genetic locus of Alba in a second Colias species, allowing us to compare this with previous results in a larger phylogenetic context. Our findings suggest Alba has a singular origin and has been maintained in Colias through a combination of balancing selection and introgression for nearly one million years and at least as many generations. Finally, using CRISPR/Cas9 deletions in the cis-regulatory region of the Alba allele, we demonstrate that the Alba allele is a modular enhancer for the BarH1 gene and is necessary for the induction of the ALHS, which potentially facilitates its long-term persistence in the genus.

scholarly journals Coevolution between life-history and metabolic rate depends on ontogenetic stage

2019 ◽  
Author(s):  
Will Sowersby ◽  
Sergey Morozov ◽  
Simon Eckerström-Liedholm ◽  
Philipp Lehmann ◽  
Piotr K. Rowiński ◽  
...  
Keyword(s):  
Life History ◽  
Metabolic Rate ◽  
Life History Traits ◽  
Life History Strategy ◽  
Reproductive Rate ◽  
Annual Species ◽  
Pace Of Life ◽  
Ontogenetic Stages ◽  
Trade Offs ◽  
Ephemeral Pools

AbstractMetabolic rate is considered to determine the energetic investment placed into life-history traits, regulating the speed of an organism’s life-cycle and forming the so called “pace-of-life”. However, how metabolic rate and life-history traits co-evolve remains unclear. For instance, the energetic demands of life-history traits, including the number of energy allocation trade-offs, is unlikely to remain constant over ontogeny. Therefore, the predicted coevolution between metabolic rate and life-history could be specific to particular ontogenetic stages, rather than a stable property of an organism. Here, we test the ontogenetic dependency of the coevolution between metabolic rate and the pace of life-history, under strictly standardized conditions using 30 species of killifish, which are either annual species adapted to ephemeral pools or non-annual species inhabiting more permanent waterbodies. Standard metabolic rates were estimated at three ontogenetic stages, together with relevant life-history traits, i.e. growth (juveniles), maturity (young adults), and reproductive rate (reproductive adults). Life-history traits largely followed predicted pace-of-life patterns, with overall faster/higher rates in annual species. The divergences in life-history traits across species tended to increase over ontogeny, being smallest during juvenile growth and largest in reproductive adults. However, associations between life-history strategy and metabolic rate followed a reversed pattern, being strongest in juveniles, but lowest in reproductive adults. Our results are concordant with the number of energetic trade-offs increasing over ontogeny, which results in a stronger covariation between physiology and life-history traits earlier in ontogeny.

scholarly journals The bacterial endosymbiontWolbachiaincreases reproductive investment and accelerates the life cycle of ant colonies

2019 ◽  
Author(s):  
Rohini Singh ◽  
Timothy A. Linksvayer
Keyword(s):  
Life History ◽  
Life Cycle ◽  
Life History Strategy ◽  
Reproductive Investment ◽  
Ant Colonies ◽  
Eusocial Insects ◽  
History Of ◽  
Young Life ◽  
Colony Level

AbstractWolbachiais a widespread group of maternally-transmitted endosymbiotic bacteria that often manipulates the reproductive strategy and life history of its solitary hosts to enhance its own transmission.Wolbachiaalso commonly infects eusocial insects such as ants, although the effects of infection on social organisms remain largely unknown. We tested the effects of infection on colony-level reproduction and life history traits in the invasive pharaoh ant,Monomorium pharaonis. First we compared the reproductive investment of infected and uninfected colonies with queens of three discrete ages, and we found that infected colonies had increased reproductive investment. Next, we compared the long-term growth and reproduction of infected and uninfected colonies across their life cycle, and we found that infected colonies had increased colony-level growth and early colony reproduction. These colony-level effects ofWolbachiainfection seem to result because of a ‘live fast, die young’ life history strategy of infected queens. Such accelerated colony life cycle is likely beneficial for both the host and the symbiont and may have contributed to success of the highly invasive pharaoh ant.

Sign in / Sign up

Export Citation Format

Share Document