Factors affecting abandonment and adoption of young in common eiders and other waterfowl: a comment

1995 ◽  
Vol 73 (8) ◽  
pp. 1575-1577 ◽  
Author(s):  
Hannu Pöysä
Keyword(s):  
Survival Rate ◽  
Final Decision ◽  
Somateria Mollissima ◽  
Factors Affecting ◽  
Lower Survival Rate ◽  
Investment Theory ◽  
Common Eiders ◽  
Parental Investment Theory ◽  
Brood Success ◽  
Care Period

Factors affecting abandonment and adoption of young have been studied extensively in waterfowl. Several hypotheses have been advanced to account for these behaviours, and Bustnes and Erikstad (J.O. Bustnes and K.E. Erikstad. 1991. Can. J. Zool. 69: 1538–1545) recently evaluated these in common eiders (Somateria mollissima). They found, among other things, that young of "abandoners" had a lower survival rate than young of "tenders," but were not able to accurately time the mortality of ducklings. I propose a hypothesis based on brood success and parental investment theory to explain why some parents abandon their young exceptionally early and why some parents tend their own as well as foreign young. According to the hypothesis, parents provide relatively less care for offspring that are surviving less than average during the parental care period. The low survival of the young of abandoners while they are still with their own mother may have influenced the final decision of common eider females to abandon their broods early.

Parental care in the common eider (Somateria mollissima): factors affecting abandonment and adoption of young

1991 ◽  
Vol 69 (6) ◽  
pp. 1538-1545 ◽  
Author(s):  
Jan O. Bustnes ◽  
Kjell E. Erikstad
Keyword(s):  
Parental Care ◽  
Somateria Mollissima ◽  
Factors Affecting ◽  
Lower Survival Rate ◽  
Duckling Survival ◽  
Energetic Stress ◽  
Lower Body Weight ◽  
Common Eiders ◽  
The Common ◽  
Individual Strategies

Parental care in common eiders (Somateria mollissima) was studied during three field seasons in northern Norway. Forty-two percent of the females were found to abandon their brood. Abandonment and tending of broods and crèches were not obligate individual strategies, but changed between years. Females abandoning their young laid smaller clutches and had a lower body weight at hatching than brood- and crèche-tending females, indicating that they were in poor body condition. This supports the hypothesis that abandoning the brood is a salvage strategy in which energetic stress limits females' ability to care for their young. Young of "abandoners" seemed to have a lower survival rate than young of "tenders," which suggests a reproductive cost of abandoning the young. Forty-seven percent of tagged ducklings were found with females other than their mother. Twenty-seven percent of the brood- and crèche-tending females lost young to other females, but never more than one duckling. Adoptions of foreign ducklings, above the normal brood size of four, did not lead to greater parental effort, and duckling survival was similar among broods and crèches of different sizes. This suggests that adoptions may be of neutral adaptive value. Two females often formed stable crèches, but duckling survival was not significantly different from that in broods and crèches with single females.

Genetic and non-genetic factors affecting pre-weaning survivability in kids

1990 ◽  
Vol 51 (3) ◽  
pp. 559-564 ◽  
Author(s):  
D. K. Singh ◽  
H. R. Mishra ◽  
C. S. P. Singh
Keyword(s):  
Birth Weight ◽  
Survival Rate ◽  
Linear Relationship ◽  
Survival Rates ◽  
Genetic Group ◽  
Season Of Birth ◽  
Factors Affecting ◽  
Lower Survival Rate ◽  
Filial Generation ◽  
Group Sex

ABSTRACTThe present study was carried out on 1243 kids (379 Black Bengal; 568 Jamunapari × Black Bengal and 296 Beetal × Black Bengal) born between 1981 and 1986. Data were analysed to study the influence of genetic group, sex, season of birth, type of birth, birth weight, dam's weight at kidding, filial generation and parity of dam (as covariate) on survivability of kids during the pre-weaning period (0 to 90 days of age). The overall survival rates during 0 to 15, 16 to 30, 31 to 60, 61 to 90 and 0 to 90 days of age were 81·68 (s.e. 2·89), 95·55 (s.e. 2·00), 90·77 (s.e. 2·33), 93·31 (s.e. 2·59) and 69·94 (s.e. 3·65) % respectively. Variation in survival rates from 0 to 15 days of age was significant due to genetic group (P < 0·01), birth weight (P < 0·01), dam's weight at kidding and parity of dams as a covariate (P < 0·05). Season of birth (P < 0·05), weight of kids (P < 0·01) and dam's weight at kidding (P < 0·01) had significant effects on survival rate during 0 to 90 days of age. Sex and type of birth had no significant effect on survival rates. The interaction effects of genetic groups with season of birth and sex on pre-weaning survival rates were not significant in all ages except the effect between genetic group and sex during 31 to 60 days of age. An improvement in survival rates during the period of study was noticed with the increase in filial generation number from Fj to F3, although the difference was not significant except from 61 to 90 days of age (P < 0·05). Birth weight of kids had a positive linear relationship with survivability during the pre-weaning period. Summer-born kids had a significantly lower survival rate than those born in the winter and monsoon periods from 16 to 30, 61 to 90 and from 0 to 90 days of age. A negative linear relationship was observed between dam's weight at kidding and survival rates of kids from 0 to 90 days of age except the 25 to 30 kg dams deviate. Heritability estimates of survival rates during pre-weaning periods were not significantly different from zero, indicating that improvement by simple selection is probably limited.

scholarly journals Preoperative C-reactive protein as a prognostic factor in stage IV colorectal cancer

2021 ◽  
Author(s):  
Hiroka Kondo ◽  
Yasumitsu Hirano ◽  
Toshimasa Ishii ◽  
Shintaro Ishikawa ◽  
Takatsugu Fujii ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Survival Rate ◽  
Stage Iv ◽  
Time Frame ◽  
Long Term Results ◽  
Factors Affecting ◽  
Lower Survival Rate ◽  
Reactive Protein ◽  
Stage Iv Colorectal Cancer ◽  
Colorectal Cancer Patients

Background A prognosis for stage IV colorectal cancer is generally poor. As a result, the development of an appropriate treatment strategy for each individual with this disease within a limited time frame is important. Few studies have been made of CRP in stage IV cases of colorectal cancer so it is unclear whether CRP is a useful prognostic marker for this disease. Thus, the purpose of this study was to clarify the relationship between the preoperative CRP level and the prognosis of stage IV colorectal cancer. Patients and methods Between April 2007 and December 2015, 384 patients with stage IV colorectal cancer who underwent primary resection were included. Patients were divided into high (HCG) and low (LCG) CRP groups based on a preoperative CRP cut-off value of ≥1.0 mg/dL. Postoperative short- and long-term results were examined retrospectively. Results The 5-year survival rate was 24.6% for HCG and 36.7% for LCG, indicating the survival rate for HCG was lower. The study was limited to patients who were unable to undergo R0 surgery. Preoperative CEA levels were higher in HCG while the postoperative chemotherapy induction rate was lower. HCG also showed a significantly lower survival rate than LCG. Multivariate analysis showed that CRP levels above 1.0 mg/dL, poorly differentiated histopathology, and the absence of chemotherapy were risk factors affecting overall survival. Conclusion These results suggest that the preoperative CRP level may be a useful biomarker for the prognosis of incurable stage IV colorectal cancer.

Gender differences in abdominal aortic aneurysm therapy – a systematic review

VASA ◽  
2018 ◽  
Vol 47 (4) ◽  
pp. 267-272 ◽  
Author(s):  
Konstanze Stoberock ◽  
Tilo Kölbel ◽  
Gülsen Atlihan ◽  
Eike Sebastian Debus ◽  
Nikolaos Tsilimparis ◽  
...  
Keyword(s):  
Gender Differences ◽  
Abdominal Aortic Aneurysm ◽  
Survival Rate ◽  
Aortic Aneurysm ◽  
Endovascular Treatment ◽  
Aortic Aneurysms ◽  
Lower Survival Rate ◽  
Lower Survival ◽  
Abdominal Aortic ◽  
Risk Of Rupture

Abstract. This article analyses if and to what extent gender differences exist in abdominal aortic aneurysm (AAA) therapy. For this purpose Medline (PubMed) was searched from January 1999 to January 2018. Keywords were: “abdominal aortic aneurysm”, “gender”, “prevalence”, “EVAR”, and “open surgery of abdominal aortic aneurysm”. Regardless of open or endovascular treatment of abdominal aortic aneurysms, women have a higher rate of complications and longer hospitalizations compared to men. The majority of studies showed that women have a lower survival rate for surgical and endovascular treatment of abdominal aneurysms after both elective and emergency interventions. Women receive less surgical/interventional and protective medical treatment. Women seem to have a higher risk of rupture, a lower survival rate in AAA, and a higher rate of complications, regardless of endovascular or open treatment. The gender differences may be due to a higher age of women at diagnosis and therapy associated with higher comorbidity, but also because of genetic, hormonal, anatomical, biological, and socio-cultural differences. Strategies for treatment in female patients must be further defined to optimize outcome.

scholarly journals THE FUTURE OF PASSENGER AIR TRANSPORT – VERY LARGE AIRCRAFT AND OUT KEY HUMAN FACTORS AFFECTING THE OPERATION AND SAFETY OF PASSENGER AIR TRANSPORT

2017 ◽  
Vol 12 ◽  
pp. 104
Author(s):  
Petra Skolilova
Keyword(s):  
Human Factors ◽  
Human Error ◽  
Operating Cost ◽  
Aircraft Design ◽  
Air Transport ◽  
Final Decision ◽  
Factors Affecting ◽  
Fuel Burn ◽  
The Future ◽  
The Impact

The article outlines some human factors affecting the operation and safety of passenger air transport given the massive increase in the use of the VLA. Decrease of the impact of the CO2 world emissions is one of the key goals for the new aircraft design. The main wave is going to reduce the burned fuel. Therefore, the eco-efficiency engines combined with reasonable economic operation of the aircraft are very important from an aviation perspective. The prediction for the year 2030 says that about 90% of people, which will use long-haul flights to fly between big cities. So, the A380 was designed exactly for this time period, with a focus on the right capacity, right operating cost and right fuel burn per seat. There is no aircraft today with better fuel burn combined with eco-efficiency per seat, than the A380. The very large aircrafts (VLAs) are the future of the commercial passenger aviation. Operating cost versus safety or CO2 emissions versus increasing automation inside the new generation aircraft. Almost 80% of the world aircraft accidents are caused by human error based on wrong action, reaction or final decision of pilots, the catastrophic failures of aircraft systems, or air traffic control errors are not so frequent. So, we are at the beginning of a new age in passenger aviation and the role of the human factor is more important than ever.

scholarly journals Herd immunity drives the epidemic fadeout of avian cholera in Arctic-nesting seabirds

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jacintha G. B. van Dijk ◽  
Samuel A. Iverson ◽  
H. Grant Gilchrist ◽  
N. Jane Harms ◽  
Holly L. Hennin ◽  
...  
Keyword(s):  
Colony Size ◽  
Pasteurella Multocida ◽  
Herd Immunity ◽  
Reproductive Number ◽  
Somateria Mollissima ◽  
Common Eiders ◽  
Serological Status ◽  
Antibody Titers ◽  
Avian Cholera

AbstractAvian cholera, caused by the bacterium Pasteurella multocida, is a common and important infectious disease of wild birds in North America. Between 2005 and 2012, avian cholera caused annual mortality of widely varying magnitudes in Northern common eiders (Somateria mollissima borealis) breeding at the largest colony in the Canadian Arctic, Mitivik Island, Nunavut. Although herd immunity, in which a large proportion of the population acquires immunity to the disease, has been suggested to play a role in epidemic fadeout, immunological studies exploring this hypothesis have been missing. We investigated the role of three potential drivers of fadeout of avian cholera in eiders, including immunity, prevalence of infection, and colony size. Each potential driver was examined in relation to the annual real-time reproductive number (Rt) of P. multocida, previously calculated for eiders at Mitivik Island. Each year, colony size was estimated and eiders were closely monitored, and evaluated for infection and serological status. We demonstrate that acquired immunity approximated using antibody titers to P. multocida in both sexes was likely a key driver for the epidemic fadeout. This study exemplifies the importance of herd immunity in influencing the dynamics and fadeout of epidemics in a wildlife population.

scholarly journals Parental investment in child health in sub-Saharan Africa: a cross-national study of health-seeking behaviour

2016 ◽  
Vol 3 (2) ◽  
pp. 150460 ◽  
Author(s):  
Caroline Uggla ◽  
Ruth Mace
Keyword(s):  
Health Status ◽  
Child Health ◽  
Birth Order ◽  
Parental Investment ◽  
Sub Saharan Africa ◽  
Health Seeking Behaviour ◽  
Health Seeking ◽  
Investment Theory ◽  
Parental Investment Theory ◽  
Sub Saharan

Parents face trade-offs between investing in child health and other fitness enhancing activities. In humans, parental investment theory has mostly been examined through the analysis of differential child outcomes, with less emphasis on the actions parents take to further a particular offspring’s condition. Here, we make use of household data on health-seeking for children in a high mortality context where such behaviours are crucial for offspring survival. Using Demographic and Health Survey (DHS) data from 17 sub-Saharan African countries, we examine whether maternal factors (age, health, marital status) and child factors (birth order, health, sex, age) independently influence parental investment in health-seeking behaviours: two preventative behaviours (malaria net use and immunization) and two curative ones (treating fever and diarrhoea). Results indicate that children with lower birth order, older mothers and mothers with better health status have higher odds of investment. The effects of a child’s sex and health status and whether the mother is polygynously married vary depending on the type of health-seeking behaviour (preventative versus curative). We discuss how these results square with predictions from parental investment theory pertaining to the state of mothers and children, and reflect on some potential mechanisms and directions for future research.

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