Haemoproteusinfected birds have increased lifetime reproductive success

Parasitology ◽  
2015 ◽  
Vol 142 (8) ◽  
pp. 1033-1043 ◽  
Author(s):  
M. ZYLBERBERG ◽  
E. P. DERRYBERRY ◽  
C. W. BREUNER ◽  
E. A. MACDOUGALL-SHACKLETON ◽  
J. M. CORNELIUS ◽  
...  

SUMMARYThe impact of haematozoan infection on host fitness has received substantial attention since Hamilton and Zuk posited that parasites are important drivers of sexual selection. However, short-term studies testing the assumption that these parasites consistently reduce host fitness in the wild have produced contradictory results. To address this complex issue, we conducted a long-term study examining the relationship between naturally occurring infection withHaemoproteusandPlasmodium, and lifetime reproductive success and survival of Mountain White-crowned Sparrows. Specifically, we tested the hypothesis that birds infected with haematozoan parasites have reduced survival (as determined by overwinter return rates) and reproductive success. Contrary to expectation, there was no relationship betweenHaemoproteusandPlasmodiuminfection and reproduction or survival in males, nor was there a relationship betweenPlasmodiuminfection and reproduction in females. Interestingly,Haemoproteus-infected females had significantly higher overwinter return rates and these females fledged more than twice as many chicks during their lifetimes as did uninfected females. We discuss the impact of parasitic infections on host fitness in light of these findings and suggest that, in the case of less virulent pathogens, investment in excessive immune defence may decrease lifetime reproduction.

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e2904 ◽  
Author(s):  
Robert F. Lynch ◽  
Emily C. Lynch

BackgroundDemonstrating the impact that parents have on the fitness of their children is a crucial step towards understanding how parental investment has affected human evolution. Parents not only transfer genes to their children, they also influence their environments. By analyzing reproductive patterns within and between different categories of close relatives, this study provides insight into the genetic and environmental effects that parents have on the fitness of their offspring.MethodsWe use data spanning over two centuries from an exceptionally accurate Icelandic genealogy, Íslendingabók, to analyze the relationship between the fertility rates of close relatives. Also, using genetic data, we determine narrow sense heritability estimates (h2) to further explore the genetic impact on lifetime reproductive success. Finally, we construct four simulations to model the expected contribution of genes and resources on reproductive success.ResultsThe relationship between the reproduction of all full sibling pairs was significant and positive across all birth decades (r = 0.19) while the reproductive relationship between parents and offspring was often negative across many decades and undetectable overall (r = 0.00) (Fig. 1 and Table 1). Meanwhile, genetic data among 8,456 pairs of full siblings revealed a narrow sense heritability estimate (h2) of 0.00 for lifetime reproductive success. A resources model (following the rule that resources are transmitted from parents to children, distributed equally among siblings, and are the only factor affecting reproductive success) revealed a similar trend: a negative relationship between parent and offspring reproduction (r =  − 0.35) but a positive relationship among full siblings (r = 0.28). The relationship between parent and offspring lifetime reproductive success (LRS) and full sibling LRS was strongly and positively correlated across time (r = 0.799,p < 0.001). Similarly, the LRS among full siblings was positively correlated with both the LRS among half siblings (r = 0.532,p = 0.011) and the relationship between the LRS of aunts and uncles with their nieces and nephews (r = 0.438,p = 0.042).DiscussionWe show that an individual’s lifetime reproductive success is best predicted by the reproduction of their full and half siblings, but not their parents, grandparents or aunts and uncles. Because all siblings share at least one parent, we believe parental investment has had an important impact on fitness. Overall, these results indicate that direct parental investment, but not genes, is likely to have had an important and persistent impact on lifetime reproductive success across more than two centuries of Icelandic history.


2020 ◽  
Vol 117 (9) ◽  
pp. 4809-4814 ◽  
Author(s):  
Svenja B. Kroeger ◽  
Daniel T. Blumstein ◽  
Kenneth B. Armitage ◽  
Jane M. Reid ◽  
Julien G. A. Martin

Annual reproductive success and senescence patterns vary substantially among individuals in the wild. However, it is still seldom considered that senescence may not only affect an individual but also affect age-specific reproductive success in its offspring, generating transgenerational reproductive senescence. We used long-term data from wild yellow-bellied marmots (Marmota flaviventer) living in two different elevational environments to quantify age-specific reproductive success of daughters born to mothers differing in age. Contrary to prediction, daughters born to older mothers had greater annual reproductive success on average than daughters born to younger mothers, and this translated into greater lifetime reproductive success. However, in the favorable lower elevation environment, daughters born to older mothers also had greater age-specific decreases in annual reproductive success. In the harsher higher elevation environment on the other hand, daughters born to older mothers tended to die before reaching ages at which such senescent decreases could be observed. Our study highlights the importance of incorporating environment-specific transgenerational parent age effects on adult offspring age-specific life-history traits to fully understand the substantial variation observed in senescence patterns in wild populations.


2015 ◽  
Vol 15 (6) ◽  
pp. 1425-1432 ◽  
Author(s):  
C. Salvinelli ◽  
A. C. Elmore

Poor water quality is a major contributing factor to disease in developing countries. Silver-coated ceramic pot filters (CPFs) are a relatively common form of household water treatment system (HWTS) representing an effective and sustainable technology for poor communities. Water production seems to be the major limiting factor of the CPF's lifetime and sustainability since low flow rates do not produce an adequate daily volume of treated water. This paper describes a long-term study of CPF flow rates under controlled conditions using three different water sources. The relationship between water characteristics and flow rate was assessed with the intent of identifying the principal parameters that impact CPF water production. The study concluded that turbidity seems to be the principal indicator in determining CPF lifetime in terms of quantity of treated water. There is no evidence that biological activity also contributes to premature failure of CPFs and the data did not indicate that chemical precipitation is responsible for the filter clogging. Manufacturers commonly conduct initial flow rate tests using clear water as a measure of quality assurance. However, the relationship between initial flow rate and average flow rate during the lifetime of the CPF should be further studied.


2014 ◽  
Vol 92 (5) ◽  
pp. 405-415 ◽  
Author(s):  
Pamela Parker ◽  
John M. Maniscalco

We conducted a long-term study to assess how tenure and territorial behaviors influence reproductive success among male Steller sea lions (Eumetopias jubatus (Schreber, 1776)). Copulations by males (n = 44) that maintained territories on a rookery in the Gulf of Alaska from 2001 to 2009 were observed using a remote video system. Approximately half of postpartum females copulated with a male in a different territory from where they gave birth. Nearly two-thirds of territorial males with known tenure were unsuccessful in copulating during their first year. Number of copulations for territorial males increased from acquisition year to year 2 with no change in subsequent years. Cluster analysis of tenure and territorial tactic variables for 15 males with observed lifetime reproductive success was used to describe multiple reproductive strategies. Characteristics of the two most successful strategies were the following: (i) males typically copulated in their first year, retained the same territories for 3–5 years, and occupied centrally located coastal territories where the highest percentage of females gave birth and (ii) males did not copulate until at least their third year and occupied peripheral territories with fewer births for a longer tenure of 7–8 years. Results indicated that lifetime reproductive success was not achieved solely by time on the breeding area; rather, it was achieved from a combination of tenure and territorial tactics.


2016 ◽  
pp. 59-70
Author(s):  
Ninh Le Khuong ◽  
Nghiem Le Tan ◽  
Tho Huynh Huu

This paper aims to detect the impact of firm managers’ risk attitude on the relationship between the degree of output market uncertainty and firm investment. The findings show that there is a negative relationship between these two aspects for risk-averse managers while there is a positive relationship for risk-loving ones, since they have different utility functions. Based on the findings, this paper proposes recommendations for firm managers to take into account when making investment decisions and long-term business strategies as well.


Author(s):  
Pham Thu Huong ◽  
Jacob Cherian ◽  
Nguyen Thi Hien ◽  
Muhammad Safdar Sial ◽  
Sarminah Samad ◽  
...  

The present study aims to determine the impact of green innovation (GI) on the overall performance of an organization while keeping the variable of environmental management (EM) as a moderator. We used a dataset consisting of four data years, from 2014 to 2017, of A-share companies listed on the Shanghai Stock Exchange (SSE). The concept of green innovation refers to the use of advancements in technology that enable savings in energy, along with the recycling of waste material. When advanced technology is utilized in the production process, the products are referred to as green products and the whole process of adopting such technologies and product design is referred to as “Corporate Environmental Management”. Such innovations improve the overall financial performance of companies as it enables them to improve their social image by reducing their carbon footprint and ensures their long-term sustainability. The main issue is the limited focus and attention given to the topic, from the perspective of companies. This research focuses on the impact of green innovation and the importance of environmental management for the sustainability of companies. Our findings suggest that the relationship between green innovation and the performance of the company is positive and verifies the existence of moderating effects of environmental management on the relationship between green innovation and firm performance. Implications are given to academia and practitioners.


2011 ◽  
Vol 279 (1733) ◽  
pp. 1560-1566 ◽  
Author(s):  
Lee Koren ◽  
Shinichi Nakagawa ◽  
Terry Burke ◽  
Kiran K. Soma ◽  
Katherine E. Wynne-Edwards ◽  
...  

Potential mechanistic mediators of Darwinian fitness, such as stress hormones or sex hormones, have been the focus of many studies. An inverse relationship between fitness and stress or sex hormone concentrations has been widely assumed, although empirical evidence is scarce. Feathers gradually accumulate hormones during their growth and provide a novel way to measure hormone concentrations integrated over time. Using liquid chromatography–tandem mass spectrometry, we measured testosterone, corticosterone and cortisol in the feathers of house sparrows ( Passer domesticus ) in a wild population which is the subject of a long-term study. Although corticosterone is considered the dominant avian glucocorticoid, we unambiguously identified cortisol in feathers. In addition, we found that feathers grown during the post-nuptial moult in autumn contained testosterone, corticosterone and cortisol levels that were significantly higher in birds that subsequently died over the following winter than in birds that survived. Thus, feather steroids are candidate prospective biomarkers to predict the future survival of individuals in the wild.


2021 ◽  
Vol 4 (7) ◽  
pp. 4-19
Author(s):  
Akmal Baltayevich Allakuliev ◽  

The article examines the interaction of the country's GDP with the state budget in the short and long term, the impact of the macro-fiscal mechanism on the country's economic growth on the example of Uzbekistan.The aim of the study is to identify dynamic correlations between the country's state budget expenditures and the economic growth of the macro-fiscal mechanism in the short and long term, as well as to analyze the approximation or rate of return of GDP and the state budget to equilibrium during various macroeconomic shocks. and hesitation.The scientific novelties of the research are:


2016 ◽  
Vol 31 (2) ◽  
pp. 312-324 ◽  
Author(s):  
Javier González-Benito ◽  
Gustavo Lannelongue ◽  
Luis Miguel Ferreira ◽  
Carmen Gonzalez-Zapatero

Purpose – The purpose of this paper is to analyse the relationship between the environmental management of purchases and firm performance. The authors examine the moderating role played by two variables: the establishment of long-term relationships with suppliers and the strategic integration of the purchasing function. Design/methodology/approach – The authors conduct an empirical study on a sample of 100 Portuguese firms. Findings – Evidence reveals that green purchasing management improves the performance of the purchasing function, although the impact is greater when the organisation forges lasting alliances with its suppliers. Originality/value – This paper contributes to the study of the consequences of introducing environmental practices into the purchasing function, especially with regards to the formation of a panel of sustainable suppliers. Specifically, this research provides evidence to show that the implementation of those practices has positive impacts on the operating performance of the purchasing function and that the said effect is greater when a firm establishes long-term relationships with its suppliers.


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