Effects of reproduction on maternal survival and subsequent reproduction in northern Peromyscus maniculatus

1992 ◽  
Vol 70 (6) ◽  
pp. 1129-1134 ◽  
Author(s):  
John S. Millar ◽  
Elissa M. Derrickson ◽  
S. T. P. Sharpe

Female survival, number of young weaned, and offspring survival were documented for 130 individual Peromyscus maniculatus in the Kananaskis Valley, southwestern Alberta. Reproductive success was highly variable, ranging from 0 to 19 young per female at weaning and from 0 to 12 young per female at the end of the breeding season. Breeding success was not related to body size of the female prior to breeding, and the commitment to reproductive processes had no negative effects on female survival or the survival of the offspring. Most of the variation in reproductive success was attributable to female survival. Females that survived the entire breeding season weaned, on average, twice as many young as females that did not survive the breeding season. We suggest that physiological and behavior compensation and local habitat effects mask potential costs of reproduction during the breeding season. We speculate that any negative effects of high reproductive success may be evident during the nonbreeding season, or prior to breeding in the spring.

Science ◽  
2019 ◽  
Vol 363 (6427) ◽  
pp. 631-635 ◽  
Author(s):  
Maria Paniw ◽  
Nino Maag ◽  
Gabriele Cozzi ◽  
Tim Clutton-Brock ◽  
Arpat Ozgul

Species in extreme habitats increasingly face changes in seasonal climate, but the demographic mechanisms through which these changes affect population persistence remain unknown. We investigated how changes in seasonal rainfall and temperature influence vital rates and viability of an arid environment specialist, the Kalahari meerkat, through effects on body mass. We show that climate change–induced reduction in adult mass in the prebreeding season would decrease fecundity during the breeding season and increase extinction risk, particularly at low population densities. In contrast, a warmer nonbreeding season resulting in increased mass and survival would buffer negative effects of reduced rainfall during the breeding season, ensuring persistence. Because most ecosystems undergo seasonal climate variations, a full understanding of species vulnerability to global change relies on linking seasonal trait and population dynamics.


2013 ◽  
Vol 91 (2) ◽  
pp. 64-70 ◽  
Author(s):  
A.A. Cohen ◽  
R. Bowman ◽  
R.K. Boughton ◽  
E. Bridge ◽  
R.S. Heiss ◽  
...  

The relationship between individual fitness and antioxidants and oxidative stress has come under increasing scrutiny of late. In particular, associations between oxidative balance indicators and reproductive success in the wild have been inconsistent in the limited prior work on this topic. Studies spanning multiple seasons and antioxidant types are particularly lacking. Here, we examined associations between reproductive success over two breeding seasons and several metrics of circulating antioxidants (antioxidant capacity, uric acid, carotenoids, and vitamin E, measured in the intervening nonbreeding season) in Florida Scrub-Jays (Aphelocoma coerulescens (Bosc, 1795)). We found that carotenoid levels in the nonbreeding season were negatively associated with reproductive success in the preceding breeding season but unassociated with that in the subsequent breeding season. This correlation may be driven by the cost of reproduction (i.e., carotenoid depletion while breeding) or some other unmeasured and intercorrelated variable such as diet. Antioxidant capacity, uric acid, and vitamin E were not associated with reproductive success. These data are consistent with an emerging theme in physiological ecology: that antioxidants and oxidative stress are but one part of a suite of integrative physiological systems that interact and trade-off in complex ways, making full understanding of their ecological roles challenging.


2020 ◽  
Vol 19 (2) ◽  
pp. 86-96
Author(s):  
Isaac A. Lindquist ◽  
Emily E. Adams ◽  
Joseph A. Allen

Abstract. Most employees participate in workplace meetings, and their experiences in meetings can vary greatly, which can lead to positive or negative effects on both job attitudes and behavior. In this study, we examined the effect that a meeting attendee’s competence in the meeting topic had on their participation in the meeting and their perception of meeting effectiveness. Results indicated those with higher levels of competence in the meeting topic were more likely to participate and through participation found their meeting more effective; this relationship was stronger when employee dissent in the meetings was high. Leaders should ensure that those who are present in a meeting are competent in the topic of the meeting and encourage them to participate.


GIS Business ◽  
2019 ◽  
Vol 14 (6) ◽  
pp. 656-666
Author(s):  
Dr. Entisar Al-Obaidi

Media refers to the channels of communication through which we distribute news, education, movies, music, advertising messages and other information. It includes physical and online newspapers and magazines, television, radio, telephone, the Internet, fax and billboards, are a dominant force in lives of children. Although television is remaining the predominant medium for children and adolescents, the new technologies are become more popular. We have to concern about the potential harmful effects of media "messages and images"; however, the positive and negative effects of media should be recognized. Parents have to establish the plan for all media in family home. Media that are influences on children should be recognized by "schools, policymakers, product advertisers, and entertainment producers".


2020 ◽  
Vol 98 (Supplement_3) ◽  
pp. 162-162
Author(s):  
Nayan Bhowmik ◽  
Kris A Ringwall ◽  
Carl R Dahlen ◽  
Kendall C Swanson ◽  
Jeffrey A Clapper ◽  
...  

Abstract Leptin is a 16-kDa-peptide hormone product of the leptin gene (LEP) that is predominantly synthesized by adipose tissues and has known involvement in regulation of feed intake, energy expenditure, reproduction, and immune functions. The objective was to determine the association of leptin genotype (LEP c.73C >T), leptin diplotype (LEPD) and plasma leptin hormone (LEPH) concentration with growth, feed intake, feed efficiency, and behavior characteristics in developing beef heifers. A total of 336 commercial beef heifers were genotyped for the LEP c.73C >T marker. Four single nucleotide polymorphism markers including LEP c.73C >T, ARS-BFGL-NGS-59298 (intron 1), BovineHD0400026029 (upstream) and BovineHD0400026063 (downstream) of LEP were considered for haplotype analysis. Eleven LEPD were identified for this study using parsimony-based analyses. Circulating levels of LEPH were measured on 333 heifers prior to their first breeding season and used to assign low or high concentration group based on population median. Data were analyzed using the mixed procedure of SAS for repeated measures, fixed effects of ancestral breed group (n = 4), dam age category (n = 4), frame size group (n = 4), project cycle nested within birth year (n = 6), week of feed trial × year, LEP (n = 3) or LEPD (n = 11) or LEPH (n = 2), as well as week × LEPH (only for LEPH). There were no significant differences between LEP genotypes (P ≥ 0.11) or LEPD (P ≥ 0.33) for any of the studied traits. Heifers with low LEPH ate fewer meals per day (P = 0.02) and had more DMI per meal (P = 0.04) compared to those with high plasma leptin. Further research is needed to better understand plasma LEPH concentration and its role in feeding behavior attributes. However, circulatory LEPH before the breeding season may serve as a predictor for feeding behavior.


Ibis ◽  
2021 ◽  
Author(s):  
Joy Coppes ◽  
Jim‐Lino Kämmerle ◽  
Karl‐Eugen Schroth ◽  
Veronika Braunisch ◽  
Rudi Suchant

Author(s):  
Anke Kloock ◽  
Lena Peters ◽  
Charlotte Rafaluk-Mohr

In most animals, female investment in offspring production is greater than for males. Lifetime reproductive success (LRS) is predicted to be optimized in females through extended lifespans to maximize reproductive events by increased investment in immunity. Males, however, maximize lifetime reproductive success by obtaining as many matings as possible. In populations consisting of mainly hermaphrodites, optimization of reproductive success may be primarily influenced by gamete and resource availability. Microbe-mediated protection (MMP) is known to affect both immunity and reproduction, but whether sex influences the response to MMP remains to be explored. Here, we investigated the sex-specific differences in survival, behavior, and timing of offspring production between feminized hermaphrodite (female) and male Caenorhabditis elegans following pathogenic infection with Staphylococcus aureus with or without MMP by Enterococcus faecalis. Overall, female survival decreased with increased mating. With MMP, females increased investment into offspring production, while males displayed higher behavioral activity. MMP was furthermore able to dampen costs that females experience due to mating with males. These results demonstrate that strategies employed under pathogen infection with and without MMP are sex dependent.


2018 ◽  
Vol 9 (2) ◽  
pp. 507-518
Author(s):  
Andrew R. Meyers ◽  
Scott A. Carleton ◽  
William R. Gould ◽  
Clay T. Nichols ◽  
David A. Haukos ◽  
...  

Abstract The lesser prairie-chicken Tympanuchus pallidicinctus has experienced significant declines in distribution and abundance since the early 1900s. A severe and prolonged drought from 2009 to 2013 resulted in further declines in population numbers and despite improved environmental and habitat conditions since 2013, populations of lesser prairie chickens have shown little improvement. To investigate whether breeding season survival of lesser prairie-chickens in eastern New Mexico could be driving this response, we developed the following objectives: 1) estimate male and female breeding-season survival; 2) determine whether male and female survival varies temporally among lekking, nesting, and brood-rearing periods; and 3) determine cause-specific mortality during the breeding season. We captured and radiocollared 76 lesser prairie-chickens (50 male, 26 female) during spring of 2014 and 2015 and estimated their survival throughout the breeding season (15 March–31 August). Male survival was nearly double that of females in both years (0.79–0.81 and 0.38–0.45, respectively). Males had similar survival across all periods (lekking, postlekking, late summer: 0.89–0.95). Females had the greatest period-specific survival during lekking and brood rearing (0.87 ± 0.08 and 0.85 ± 0.10, respectively) relative to the nesting period (0.58 ± 0.11). Mammalian predation was the primary cause of mortality in both years. Our results indicate that in New Mexico 1) lesser prairie-chicken breeding season survival was consistent with geographically similar studies, 2) females have lower survival during the nesting period, and 3) female lesser prairie-chicken survival was lower than male survival regardless of time period. Management actions that provide and protect high-quality nesting habitat may help ensure that female survival is maximized during the nesting period.


2004 ◽  
Vol 61 (11) ◽  
pp. 2135-2143 ◽  
Author(s):  
Nathan J Dorn ◽  
Gary G Mittelbach

While crayfish are traditionally considered fish prey, they are capable of feeding on substrate-bound fish eggs and their introductions have been blamed for the decline in fish populations in Europe and North America. To investigate their potential effects on fish reproductive success we measured the effects of a native crayfish (Orconectes virilis) on the reproductive success of two substrate-nesting sunfish, pumpkinseed (Lepomis gibbosus) and bluegill (Lepomis macrochirus), in replicated pond experiments. Crayfish were observed feeding on eggs in both experiments. Crayfish presence delayed successful reproduction by pumpkinseeds in densely vegetated ponds, resulting in lower young-of-the-year biomass in ponds with crayfish. In the second experiment, with bluegills in less-vegetated ponds, crayfish prevented successful reproduction entirely. However, when we added crayfish-proof exclosures to the crayfish ponds late in the summer, bluegills located the crayfish-free habitat and successfully reproduced inside the exclosures (1 month after first successful reproduction in control ponds). The results of these experiments demonstrate the potential strong negative effects of crayfish on sunfish reproduction and suggest that the spatial distribution of crayfish and other egg predators may influence fish nesting behaviors and habitat choices. Further studies are needed to determine the magnitude of crayfish effects in natural lakes and ponds where sunfish and crayfish co-occur.


Author(s):  
Leidy Alejandra Barragan Contreras ◽  
Rafael Antelo ◽  
Adolfo Amezquita

Testosterone is a steroid hormone involved in the expression of many morphological, physiological, and behavioral traits that arguably affect reproductive success. The evidence for that link is, however, incomplete or absent in the research on crocodylian species. Testosterone levels are also known to change throughout the breeding season, often on an hourly basis, which may further complicate studying their relationship with breeding success. We tested here whether baseline testosterone levels, measured out of the breeding season, are correlated with morphometry and reproductive success in Caiman crocodilus (LINNAEUS, 1758). Paternity tests, based on the amplification and genotyping of eight fluorochrome labeled microsatellites, failed to support a continuous relationship between these variables. Although adult males of all sizes contribute to reproduction, paternity was overrepresented in a few males with high values of maleness index (bigger males), supporting a despotic or pyramidal hierarchy among males. Maternity assignments supported the existence of multiple paternity, a phenomenon previously attributed in this species to the lack of large males caused by human hunting. The idea of larger males having more offspring is widespread in crocodylians, but to our knowledge, this is the first investigation that prove this dogma.


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