scholarly journals King Eider (Somateria Spectabilis) Brood Ecology: Correlates of Duckling Survival

The Auk ◽  
2007 ◽  
Vol 124 (2) ◽  
pp. 606-618
Author(s):  
Katherine R. Mehl ◽  
Ray T. Alisauskas
Keyword(s):  
Population Dynamics ◽  
Complete Loss ◽  
Female Size ◽  
Apparent Survival ◽  
Nest Failure ◽  
Hatch Date ◽  
King Eider ◽  
Somateria Spectabilis ◽  
Duckling Survival ◽  
Insight Into

AbstractEvents during duckling growth can influence waterfowl population dynamics. To gain insight into King Eider (Somateria spectabilis) brood ecology, we monitored 111 and 46 individually marked ducklings from broods of 23 and 11 radiomarked King Eiders during 2000 and 2001, respectively. We used capture-mark-resight data to model apparent survival of King Eider ducklings and broods, and multistratum analysis to estimate probabilities of (1) movement among habitats and (2) apparent survival of ducklings that used various habitats. In addition, we recorded length of stay for 7 and 18 radiomarked females with failed nesting attempts during 2000 and 2001, respectively. Complete loss of individual broods accounted for 84% of all duckling mortality (106 of 126 mortalities), with most brood loss (74%; 17 of 23 broods lost) within the first two days after hatch. Estimated apparent survival of ducklings to 24 days of age was 0.10 (95% CI: 0.05 to 0.15). Apparent survival of broods was estimated to be 0.31 (95% CI: 0.13 to 0.50). Our data suggested an interaction between female size and hatch date, whereby larger females whose ducklings also hatched earlier raised more ducklings than either small females or those with ducklings that hatched later. Overland brood movements ≥1 km occurred in both years, and survival was greatest for ducklings on smaller ponds away from the central nesting area at Karrak Lake, Nunavut. Females that experienced nest failure and total brood loss left the study area earlier than females with surviving ducklings.Écologie d'élevage des couvées de Somateria spectabilis : Corrélations avec la survie des canetons

scholarly journals Effects of Intrinsic and Extrinsic Factors on Survival of White-Winged Scoter (Melanitta Fusca Deglandi) Ducklings

The Auk ◽  
2006 ◽  
Vol 123 (1) ◽  
pp. 67-81
Author(s):  
Joshua J. Traylor ◽  
Ray T. Alisauskas
Keyword(s):  
Body Condition ◽  
Female Size ◽  
Hatch Date ◽  
Extrinsic Factors ◽  
Intrinsic Factors ◽  
Brood Survival ◽  
Duckling Survival ◽  
Offspring Sex ◽  
Melanitta Fusca ◽  
Favorable Weather

AbstractIn waterfowl, offspring survival and the effects of extrinsic (i.e. weather, hatching date) and intrinsic (i.e. physical and nutritional traits of individual females and ducklings, brood sizes) factors on it are poorly understood. In 2000 and 2001, we estimated duckling and brood survival of White-winged Scoters (Melanitta fusca deglandi) at Redberry Lake, Saskatchewan, Canada, to 30 days of age to examine relationships between duckling survival and (1) hatch date, (2) initial brood size at hatch, (3) duckling size and body condition at hatch, (4) offspring sex, (5) maternal female size and body condition at hatch, and (6) weather. We estimated survival with Cormack-Jolly-Seber models, in program MARK, from observations of individually marked adult females (n = 94) and ducklings (n = 664). Most mortality (i.e. 0.80 and 0.95 for each year, respectively) occurred within six days of hatch in both years. Duckling survival probability decreased with advancing hatch date; increased with larger initial brood sizes; was higher for larger, better-conditioned ducklings; and increased with favorable weather. Brood survival decreased with advancing hatch date, increased with larger initial brood sizes, and increased with favorable weather. For 2000 and 2001, our models predict survival probabilities of ducklings (0.0061 and 0.0027, respectively) and broods (0.015 and 0.00048, respectively) that are lower than any previously reported. We suspect that intense gull (Larus spp.) predation shortly after hatch had the largest influence on duckling survival, though results also underscore the significance of intrinsic factors.Effets des Facteurs Intrinsèques et Extrinsèques sur la Survie les Jeunes de Melanitta fusca deglandi

Population dynamics of Stenothoe valida Dana, 1852 (Amphipoda, Stenothoidae) at Cheongsapo beach of Busan, Republic of Korea

Crustaceana ◽  
2021 ◽  
Vol 94 (4) ◽  
pp. 413-429
Author(s):  
Ye Ji Lee ◽  
Won Gyu Park
Keyword(s):  
Population Dynamics ◽  
Life History ◽  
Sex Ratio ◽  
Brood Size ◽  
Ovigerous Female ◽  
Seasonal Pattern ◽  
Recruitment Rate ◽  
Republic Of Korea ◽  
Female Size ◽  
History Of

Abstract The population dynamics of Stenothoe valida Dana, 1852 were studied at Cheongsapo beach of Busan, Republic of Korea, from March 2019 to March 2020. Sampling was conducted once a month at low tide during spring tides. Specimens were grouped by the cephalic length at 0.025 mm intervals, and classified into four categories: females, ovigerous females, males and juveniles. The sex ratio, defined as females : total males + females, exceeded 0.5 during most of the study period. Brood size was significantly coupled with ovigerous female size. Two to four cohorts appeared at each study period. New cohorts occurred at almost every sampling except in the samples Jun-2, and Nov-2. Life span was estimated at 1-2 months. The juvenile ratio, the ratio of ovigerous females, and the recruitment rate estimated by FiSAT were commonly high in summer and winter. The life history of S. valida was not coupled with water temperature, but had a strong seasonal pattern.

scholarly journals Gaining insight into transcriptome‐wide RNA population dynamics through the chemistry of 4‐thiouridine

2018 ◽  
Vol 10 (1) ◽  
pp. e1513 ◽  
Author(s):  
Erin E. Duffy ◽  
Jeremy A. Schofield ◽  
Matthew D. Simon
Keyword(s):  
Population Dynamics ◽  
Insight Into ◽  
Gaining Insight

scholarly journals Host Resistance, Genomics and Population Dynamics in a Salmonella Enteritidis and Phage System

Viruses ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 188 ◽  
Author(s):  
Angela Holguín ◽  
Pablo Cárdenas ◽  
Catalina Prada-Peñaranda ◽  
Laura Rabelo Leite ◽  
Camila Buitrago ◽  
...  
Keyword(s):  
Population Dynamics ◽  
Bacterial Infections ◽  
Salmonella Enteritidis ◽  
Phage Therapy ◽  
Salmonella Enterica Serovar Enteritidis ◽  
Antagonistic Coevolution ◽  
Bacterial Dynamics ◽  
Subsequent Time ◽  
Insight Into ◽  
Time Point

Bacteriophages represent an alternative solution to control bacterial infections. When interacting, bacteria and phage can evolve, and this relationship is described as antagonistic coevolution, a pattern that does not fit all models. In this work, the model consisted of a microcosm of Salmonella enterica serovar Enteritidis and φSan23 phage. Samples were taken for 12 days every 48 h. Bacteria and phage samples were collected; and isolated bacteria from each time point were challenged against phages from previous, contemporary, and subsequent time points. The phage plaque tests, with the genomics analyses, showed a mutational asymmetry dynamic in favor of the bacteria instead of antagonistic coevolution. This is important for future phage-therapy applications, so we decided to explore the population dynamics of Salmonella under different conditions: pressure of one phage, a combination of phages, and phages plus an antibiotic. The data from cultures with single and multiple phages, and antibiotics, were used to create a mathematical model exploring population and resistance dynamics of Salmonella under these treatments, suggesting a nonlethal, growth-inhibiting antibiotic may decrease resistance to phage-therapy cocktails. These data provide a deep insight into bacterial dynamics under different conditions and serve as additional criteria to select phages and antibiotics for phage-therapy.

scholarly journals Structure–function studies of human deoxyhypusine synthase: identification of amino acid residues critical for the binding of spermidine and NAD

2001 ◽  
Vol 355 (3) ◽  
pp. 841-849 ◽  
Author(s):  
Chang Hoon LEE ◽  
Patrick Y. UM ◽  
Myung Hee PARK
Keyword(s):  
Crystal Structure ◽  
Enzyme Activity ◽  
Amino Acid ◽  
Binding Sites ◽  
Binding Pocket ◽  
Complete Loss ◽  
Amino Acid Residues ◽  
Deoxyhypusine Synthase ◽  
Positive Identification ◽  
Insight Into

Deoxyhypusine synthase catalyses the first step in the biosynthesis of hypusine [Nε-(4-amino-2-hydroxybutyl)lysine]. The crystal structure of human deoxyhypusine synthase in complex with NAD revealed four NAD-binding sites per enzyme tetramer, and led to a prediction of the spermidine-binding pocket. We have replaced each of the seven amino acid residues at the predicted spermidine-binding site, and eleven residues that contact NAD, on an individual basis with alanine. Of the amino acid residues at the spermidine site, substitution of Asp-243, Trp-327, His-288, Asp-316 or Glu-323 with alanine caused an almost complete loss of spermidine binding and enzyme activity; only the mutation Tyr-305 → Ala showed partial binding and activity. His-288 → Ala was also deficient in terms of binding NAD. NAD binding was significantly reduced in all of the NAD-site mutant enzymes, except for Glu-137 → Ala, which showed a normal binding of NAD, but was totally lacking in spermidine binding. Of the NAD-site mutant enzymes, Asp-342 → Ala, Asp-313 → Ala and Asp-238 → Ala displayed the lowest binding of NAD. These enzymes and His-288Ala also showed a reduced binding of spermidine, presumably because spermidine binding is dependent on NAD. These findings permit the positive identification of amino acid residues critical for binding of spermidine and NAD, and provide a new insight into the complex molecular interactions involved in the deoxyhypusine synthase reaction.

Some Observations On Foraging Behaviour In The Southern Ningaui, Ningaui Yvonneae

2001 ◽  
Vol 23 (1) ◽  
pp. 59 ◽  
Author(s):  
G Bos Darren
Keyword(s):  
Population Dynamics ◽  
Habitat Selection ◽  
Arid Regions ◽  
Foraging Behaviour ◽  
Research Project ◽  
Insight Into ◽  
Semi Arid

THE southern ningaui (Ningaui yvonneae) is a small dasyurid inhabiting semi-arid regions of southern Australia. It is a nocturnal predator, feeding mainly on small invertebrates (Woolnough and Carthew 1996; Fisher and Dickman 1993). During a larger research project examining population dynamics. habitat selection and diet, I observed and documented aspects of the foraging behaviour of N. yvonneae. These observations, which are difficult to quantify, provide insight into the ecology of this poorly studied species.

Reproduction and denning by urban and rural San Clemente Island foxes (Urocyon littoralis clementae)

2011 ◽  
Vol 89 (10) ◽  
pp. 976-984 ◽  
Author(s):  
N.P. Gould ◽  
W.F. Andelt
Keyword(s):  
Population Dynamics ◽  
Rural Areas ◽  
Human Disturbance ◽  
Urban Areas ◽  
Channel Islands ◽  
California Channel Islands ◽  
Urocyon Littoralis ◽  
Urban And Rural Areas ◽  
Insight Into ◽  
San Clemente Island

Island foxes ( Urocyon littoralis (Baird, 1858)) have experienced severe reductions in populations on 4 out of 6 California Channel Islands. Although numbers of foxes on San Clemente Island (SCLI; Urocyon littoralis clementae Merriam, 1903) have remained relatively stable, data on reproductive success in urban and rural areas are necessary to better understand population dynamics of foxes and manage the population if it sustains declines. Determining locations and characteristics of den sites will also assist in minimizing possible impacts of humans on foxes. We found that 10 female foxes produced at least 19 kits during 2008. Female foxes that spent a greater proportion of time within an urban area had greater probability of reproducing compared with foxes that infrequently utilized urban areas. However, these “urban” foxes often selected den sites nearer to roads, which may expose them to increased mortalities. We located 23 den sites on a mean of 17°–18° slopes with 40% having westerly facing aspects. We recommend avoiding human disturbance to these areas from February through June, which may minimize potential impacts on foxes. Our study should provide insight into managing island foxes, especially in respect to urban areas on other Channel Islands.

scholarly journals Modeling and Analysis of Population Dynamics of Examination Malpractice Among Students

2018 ◽  
Author(s):  
Chinedu Obasi ◽  
Collins Obiora ◽  
Godwin Mbah ◽  
Oluseye Olawuyi
Keyword(s):  
Mathematical Model ◽  
Population Dynamics ◽  
Social Problem ◽  
Control Strategies ◽  
Equilibrium Points ◽  
Asymptotically Stable ◽  
Awareness Campaign ◽  
Modeling And Analysis ◽  
The Impact ◽  
Insight Into

While examination malpractice has been a recognized social problem among students, the control of the phenomenon remains a challenge. In this study, we formulate a mathematical model describing the population dynamics of examination malpractice among students. Initial insight into the dynamics of the model is gained by analyzing some important mathematical features of the model such as the basic malpractice number. The malpractice-free equilibrium and endemic equilibrium points of the model are shown to be locally asymptotically stable when the basic malpractice number is less than unity. This result implies that examination malpractice can be totally eradicated among students when the basic malpractice number is less than unity. To understand the impact of controlling this social problem, we extend the model to incorporate awareness campaign and disciplinary measure as control strategies in curtailing the act. Our analysis reveals that incorporating control strategies have some influence in reducing examination malpractice among students. Further analysis indicates that considering both control strategies simultaneously yields a better result in reducing examination malpractice and examination malpractice will grow faster when control strategies are not introduced.

scholarly journals What do we know about survival of Common cranes? An elementary introduction with Euring databank

2021 ◽  
Author(s):  
Luis M. Bautista ◽  
Juan C. Alonso
Keyword(s):  
Population Dynamics ◽  
Western Europe ◽  
Great Increase ◽  
Survival Rates ◽  
Apparent Survival ◽  
Elapsed Time ◽  
In Captivity ◽  
Species Population ◽  
Grus Grus ◽  
Common Crane

The increase of the western populations of Common cranes (Grus grus) in the last five decades highlights the need to estimate survival rates. According to Euring databank (EDB), the oldest Common crane ever known was 27 years old in year 2017. This lifespan was obtained by means of 24,900 recoveries of 2,124 ringed cranes collected between years 1936 and 2017. Nearly all cranes were ringed and observed in the last 30 years, and therefore the elapsed time was not enough to reach the maximum longevity reported for the species in captivity (43 years, Mitchell 1911). Life expectancy was five years on average after the ring was attached. Here we provide some elementary analyses to calculate the annual apparent survival rate (ϕ = 0.85) and the annual encounter probability (p = 0.45) of Common cranes, as a first step to advance in the knowledge of the species' population dynamics. The great increase of breeding and wintering crane populations in western Europe in the last decades remains largely unexplained.

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