Aspects of survival in juvenile polar bears

1996 ◽  
Vol 74 (7) ◽  
pp. 1246-1252 ◽  
Author(s):  
Andrew E. Derocher ◽  
Ian Stirling
Keyword(s):  
Maternal Age ◽  
Polar Bear ◽  
Survival Rates ◽  
Mortality Factor ◽  
First Year ◽  
Hudson Bay ◽  
Maternal Condition ◽  
Sampling Regime ◽  
Fat Stores ◽  
First Year Of Life

We captured, weighed, tagged, and monitored polar bear (Ursus maritimus) cubs and yearlings in western Hudson Bay to examine survival rates and correlates with survival. Cub survival between spring and autumn increased with cub mass and maternal mass, but was not related to maternal age or maternal condition. Cub survival between spring and autumn varied annually between 39.0 and 100.0% and averaged 53.2%. Whole-litter loss between spring and autumn was 30.8%, and only 38.0% of the females did not lose any cubs. Survival of spring twins was similar regardless of size, but in triplet litters, survival between spring and autumn varied according to cub size. Minimum cub survival from one autumn to the next was 34.7% and was related to cub mass, maternal mass, and maternal condition. Cub survival during autumn was estimated at 83.0%. Survival during the first year of life was no more than 44.0% but we could not estimate an annual survival rate because of the sampling regime. Possibly because harvesting was the major mortality factor for yearlings (19.4% of the yearlings were removed from the population per year), no factors examined correlated with survival of yearlings. We found no sex-related differences in survival of cubs or yearlings in any period. Relationships between survival in polar bear cubs and their condition suggest that lack of food availability, sometimes due to low maternal fat stores for lactation, leads to starvation and may be the main cause of mortality.

scholarly journals Mothers' perceptions of their premature infant's communication: A description of two cases

2016 ◽  
Vol 21 ◽  
pp. 143-154
Author(s):  
Michelle Pascoe ◽  
Divya Bissessur ◽  
Pat Mayers
Keyword(s):  
At Risk ◽  
Premature Infants ◽  
Developmental Delays ◽  
Survival Rates ◽  
Physical Contact ◽  
First Year ◽  
Communication Development ◽  
Early Communication ◽  
Communication Difficulties ◽  
First Year Of Life

Background: Survival rates of premature infants have increased due to advances in medicine. Premature infants however, remain at risk for developmental delays including communication difficulties. The bonding and attachment experiences of premature infants and their parents are often challenged, further placing these infants at risk for communication difficulties. This study firstly aimed to explore mothers' perceptions of their premature infants' communication. The second aim was to explore the mothers' perceptions of their own role in the communication development of their infants.Methods: A descriptive, longitudinal study was conducted with two mother—infant dyads.Three visits took place in the first year of life. Subjective maternal reports were obtained through semi-structured interviews.Results: Differences in the two mothers' perceptions were noted. The mothers described helping their infants to communicate through physical contact and talking. Risk and protective factors for early communication development are discussed in relation to the findings.Conclusion: The findings support the need for a healthy mothereinfant relationship in the first few months of life. Health professionals should support premature infants and their families after discharge in order to help them interact with their infants and encourage attachment and bonding.

First-year survival of great horned owls during a peak and decline of the snowshoe hare cycle

1996 ◽  
Vol 74 (6) ◽  
pp. 1092-1097 ◽  
Author(s):  
Christoph Rohner ◽  
D. Bruce Hunter
Keyword(s):  
Survival Rates ◽  
Bird Species ◽  
Population Cycle ◽  
First Year ◽  
Mortality Factors ◽  
Bubo Virginianus ◽  
Slow Development ◽  
Snowshoe Hares ◽  
First Year Of Life ◽  
The Cost

Most bird species have low survival rates in their first year of life, and the highest losses occur when juveniles become independent and disperse. Young great horned owls (Bubo virginianus), monitored by telemetry in the southwestern Yukon, Canada, survived well during the peak of the population cycle of snowshoe hares (Lepus americanus). Subsequently, juvenile survival collapsed parallel to the decline in hare densities. The proportion of starving owls did not increase, but there was a significant increase in mortalities involving parasitism and predation, probably as an interaction with food shortage. The mortality rates of juvenile great horned owls peaked before, not during, dispersal. We propose that extended parental care makes the postfledging stage safe during optimal conditions, but that the relatively slow development during this stage incurs the cost of increased susceptibility to disease and other mortality factors under environmental stress.

scholarly journals Variability of demographic parameters and population dynamics of Atlantic salmon Salmo salar L. in a south-west French river

2003 ◽  
Vol 60 (2) ◽  
pp. 356-370 ◽  
Author(s):  
J. Dumas ◽  
P. Prouzet
Keyword(s):  
Survival Rate ◽  
Survival Rates ◽  
Maximum Yield ◽  
First Year ◽  
South West ◽  
Salmon Population ◽  
Second Year ◽  
First Year Of Life ◽  
French River ◽  
Good Agreement

Abstract The abundance of the salmon population in the Nivelle River was assessed for 11 cohorts during all the stages of their life cycle, from eggs to spawners. A stochastic life history model was used to simulate the changes in numbers at each stage over several years and to evaluate the parameters of a Ricker-type Stock and Recruitment (S–R) relationship. Parameters necessary for managing the exploitation of the species were also estimated. The results indicated that an average deposition of 611 700 eggs (values varying in a proportion of 1 to 3, depending on the year) produced 4870 0+ parr in autumn (variation from 1 to 5.6); 71.8% of which belonged to the group of future 1-year old smolts. The age 1+ parr were eight times less numerous. Survival from egg to 0+ parr was on average 0.97%, but highly variable (varying from 1 to 15). It was density-dependent and followed Ricker S–R model with an optimum of 7800 parr for a survival rate of 3%. During their second year, the survival of 1+ parr reached 53.4% and varied little. The adult runs of complete cohorts amounted to 196 maiden salmon (range, 88 to 382) and previous spawners comprised only 0.9% of adults. Grilse (1 year in the sea) constituted the majority (88.7%). The overall survival rates from 0+ parr to adult returns (6.2% on average) varied three-fold. The majority was females among the grilse (56.2%) and 2-sea-year salmon (88.6%); all 3-sea-year adults were female. Eggs deposited per female averaged 4200, 8500 and 12 750 eggs in each age group, respectively. Simulations of population abundances at various life stages were in good agreement with the observed data. The S–R relationship revealed the low productivity and the vulnerability of this stock, mainly due to the low survival rate of the young during their first year of life. The maximum yield of 12.2% of recruits could be obtained from a deposition of 1 424 000 eggs, which is twice the present average level.

scholarly journals High philopatry rates of Yellow-legged Gulls in the southeastern part of the Bay of Biscay

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Sergio Delgado ◽  
Alfredo Herrero ◽  
Asier Aldalur ◽  
Juan Arizaga
Keyword(s):  
Survival Rates ◽  
First Year ◽  
Bay Of Biscay ◽  
Older Individuals ◽  
Southeastern Part ◽  
High Dispersal ◽  
Colonial Seabirds ◽  
Larus Michahellis ◽  
Main Food Source ◽  
First Year Of Life

Abstract Background Philopatry rate is one of the main factors shaping population dynamics in colonial seabirds. Low rates of philopatry are linked to populations with high dispersal, while high rates are linked to populations with a very high spatial structure pattern (i.e., metapopulations). The Cantabrian Yellow-legged Gull (Larus michahellis) population is considered to be resident, with relatively low dispersal rates. Precise estimations of its philopatry rates are however still lacking. Here, we aimed to estimate philopatry rates in the main Yellow-legged Gull colonies of the province of Gipuzkoa, in the southeastern part of the Bay of Biscay. Methods We analysed 734 resightings, during the breeding season at the colonies of Getaria, Santa Clara and Ulia, relative to a total of 3245 individuals ringed at birth in these same colonies during a period of 13 years. These data were analysed using Multi-State Recapture models in MARK. Results After controlling survival and resighting probability, the average dispersal rate among colonies was 4% (± SD = 2%) when individuals are immature, decreasing to 1 ± 1%) for adult breeding gulls (i.e., philopatry rate was 99%). Annual survival rates were assessed to be 0.27 ± 0.02 for birds in their first year of life and 0.87 ± 0.01 for older individuals. The probability of observing immature birds in the colonies was 0.08 ± 0.01, as compared to 0.21 ± 0.02 in adult birds. Conclusions We obtained evidence of extremely high local philopatry rates, clearly within the upper limit found in gulls. A high philopatry favour a speciation in these species who are vulnerable to obtain the main food source (landfills and fishing discard) which are transforming under new ecological process.

scholarly journals Factors Associated With Weight, Length, and BMI Change in Adolescents' Offspring in Their First Year of Life

2021 ◽  
Vol 9 ◽  
Author(s):  
Reyna Sámano ◽  
Gabriela Chico-Barba ◽  
Hugo Martínez-Rojano ◽  
María Hernández-Trejo ◽  
Mery Birch ◽  
...  
Keyword(s):  
Socioeconomic Status ◽  
Adolescent Mothers ◽  
Exclusive Breastfeeding ◽  
Maternal Age ◽  
Complementary Feeding ◽  
Chronological Age ◽  
First Year ◽  
Z Score ◽  
The Mean ◽  
First Year Of Life

Background: Young maternal age is associated with negative outcomes at birth and with offspring's growth. In low- and middle-income countries, adolescents' offspring growth little has been studied.Objective: To determine the association of maternal sociodemographic characteristics with weight, length, and BMI change in adolescents' offspring in their first year of life.Methods: This is a one-year follow-up study that included adolescent mothers and their offspring from 2010 to 2017. The infant anthropometric variables were performed at birth, 3, 6, and 12 months. Maternal health, pregnancy, and social variables were evaluated as well as birth outcomes. Crude, percentage, Z score, and percentile changes of weight, length, and BMI were evaluated from birth to 1-year-old. Statistical analyses were adjusted by maternal chronological age, socioeconomic status, breastfeeding duration, the timing of introduction of complementary feeding, among other variables.Results: We examined 186 dyads (mother-infant). The median maternal age was 15.5 years, and the mean pre-pregnancy BMI was 20. The mean gestational age was 39.1 weeks for infants, birth weight was 3,039 g, and length at birth was 49.5-cm. Maternal chronological age, the timing of introduction of complementary feeding, socioeconomic status, and maternal occupation were associated with offspring's weight gain at 12 months. Length gain was associated with exclusive breastfeeding. Socioeconomic status and occupation were associated with offspring's BMI change. When performing adjusted multivariable analyses, weight and length at birth were associated weight and BMI at 12 months.Conclusions: Weight at birth may negatively predict infant's weight and BMI changes at 12 months, while length at birth may positively predict the changes. Maternal chronological age, socioeconomic level, occupation, and the timing of the introduction of complementary feeding were associated with the weight change. Only exclusive breastfeeding was associated with length Z-score change in adolescents' offspring in their first 12-months of life.

scholarly journals Impact of birth characteristics, breast feeding and vital statistics on the eruption of primary teeth among healthy infants in Saudi Arabia: an observational study

BMJ Open ◽  
2017 ◽  
Vol 7 (12) ◽  
pp. e018621 ◽  
Author(s):  
Kholoud Abdullah Alnemer ◽  
Sharat Chandra Pani ◽  
Alaa M Althubaiti ◽  
Manal Bawazeer
Keyword(s):  
Saudi Arabia ◽  
Birth Weight ◽  
Observational Study ◽  
Breast Feeding ◽  
Maternal Age ◽  
Primary Teeth ◽  
First Year ◽  
First Year Of Life ◽  
Type Of Delivery ◽  
Weight Percentile

ObjectivesThis study aimed to explore the impact of gender, birth weight, maternal age, type of delivery, gestational age and feeding practices on the eruption of teeth in children with no underlying medical conditions or developmental defects in their first year of life.DesignA cross-sectional observational study design was used.SettingA primary healthcare setting in Riyadh, Saudi Arabia.ParticipantsAll children in their first year of life attending a vaccination clinic (n=422) were included in the study. Infants with chronic childhood illnesses, those who were below the 5th percentile in height or weight, infants with congenital birth defects and chronic illnesses, infants who were born preterm and low birth weight infants were excluded from the study.Outcome measuresThe type of delivery, birth weight, age of mother, height and weight percentile for age (as plotted on the WHO growth chart for infants) and feeding practices were recorded by the examiner, and this was followed by a clinical examination to determine the presence or absence of each tooth. Regression models were developed to determine the effect of the different variables on the presence of primary teeth.ResultsThere was a significant association between the weight percentile of the child (adjusted for age) and the number of erupted primary teeth, suggesting that heavier children have an earlier eruption of teeth. No association was observed between birth weight, height percentile for age or maternal age at the time of birth and the number of erupted primary teeth. Children who were exclusively breast fed were significantly more likely to have an erupted first primary tooth earlier than non-breastfed group.ConclusionsBreast feeding and the weight of the child may have an influence on the eruption of primary teeth in the first year of life.

Young Paternal Age and Risk Of Infant Acute Lymphoblastic Leukemia

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 1395-1395 ◽  
Author(s):  
Julie A Ross ◽  
Todd E Druley ◽  
Kimberly J Johnson ◽  
Rachel K. Fonstad ◽  
Julie von Behren ◽  
...  
Keyword(s):  
Acute Leukemia ◽  
Maternal Age ◽  
Lymphoblastic Leukemia ◽  
The United States ◽  
In Utero ◽  
Paternal Age ◽  
First Year ◽  
Parental Age ◽  
Increased Risk ◽  
First Year Of Life

Abstract Background Acute leukemia is extremely rare in the first year of life: about 150 cases are diagnosed each year in the United States. Clinical and molecular studies of infant acute leukemia (IAL) suggest a distinct etiology and provide strong evidence of an in utero origin. Little is known about IAL etiology; however, advanced maternal age (adjusted for paternal age) has been associated with an increased risk of childhood cancers diagnosed between 0-14 years of age including leukemia (both acute lymphoblastic (ALL) and acute myeloid leukemia (AML)), lymphoma, central nervous system tumors, neuroblastoma, Wilms’ tumor, bone tumors and soft tissue sarcoma, while associations with paternal age after adjusting for maternal age are less striking. Methods Linked birth and cancer registry data for the period 1980-2004 were pooled from five states (NY, WA, MN, TX and CA) to evaluate associations between birth characteristics and IAL. The pooled data contained information for 351 infants diagnosed with acute leukemia (220 ALL, 131 AML) in the first year of life and 57,966 infant controls born in the same years. Children with Down syndrome documented at birth were excluded. Unconditional logistic regression was used to calculate odds ratios (ORs) and 95% confidence intervals (CIs). Results Overall, males had a slightly decreased risk of developing IAL (OR=0.8, CI 0.7, 1.0), but there was little evidence of association with plurality, birth weight or maternal race. After adjusting for paternal age, infants with mothers ≥40 years of age had a significantly increased risk of developing IAL (OR=2.9, CI 1.4, 5.9), which was confined to the AML subtype (OR=5.5, 95% CI 2.1-14.6). In contrast, young paternal age <20 years (adjusted for maternal age) was associated with a significantly increased risk of IAL (OR=2.7, CI=1.4, 5.3), which was confined to the ALL subtype (OR=4.4, CI=1.9-10.0). Discussion Ours is the first study to demonstrate a strong significant association of paternal young age with infant ALL. Since this study ascertained case and control status by record linkage, selection bias-- where cases or controls determine extent of participation-- is of little concern. Recall bias is also unlikely, as parental age was recorded prior to cancer diagnosis. These intriguing associations provide further evidence of differences in underlying etiology for IAL. Of note, approximately 80% of infants with ALL and 60% of infants with AML have a rearrangement involving the MLL gene in their leukemia cells, which has been shown to arise in utero. Given our findings, parental age associations with MLL rearrangements in IAL need to be investigated. Further, while epidemiological studies of IAL have primarily focused on maternal factors that may increase risk, our data suggest that paternal factors also need to be considered. Future IAL research to help elucidate the biological basis should include collection of detailed epidemiological data and biospecimens from both parents and infants to determine whether parent-of-origin de novo mutations and/or carcinogenic exposures are involved. Disclosures: No relevant conflicts of interest to declare.

DISEASE AS A CONTROL OF A POPULATION OF BLUE GROUSE, DENDRAGAPUS OBSCURUS FULIGINOSUS (RIDGWAY)

1955 ◽  
Vol 33 (3) ◽  
pp. 195-223 ◽  
Author(s):  
J. F. Bendell
Keyword(s):  
New Records ◽  
Population Control ◽  
Mortality Factor ◽  
First Year ◽  
Population Stability ◽  
Adult Males ◽  
Age Classes ◽  
Dendragapus Obscurus ◽  
Summer Range ◽  
First Year Of Life

A population of blue grouse was studied on its summer range at Quinsam Lake, Vancouver Island, to determine the factors of importance in population control. The population is stable with a density of 0.40 adult males and 0.78 yearling and adult females to the acre. A life table is constructed on the basis of a stable population, the death of 80% of the chicks in the first three months after hatch, and the death of 31% of the adults each year, as calculated from banding returns. The survivorship curve is negatively "J"-shaped. Mortality rates appear constant and independent of age after the first year of life. Space, weather, food, predators, and disease are considered as factors capable of population control. Six parasites are new records in this host. Two of the six, Plagiorhynchus formosus and Dispharynx nasuta occur commonly and almost exclusively in the chicks, where they cause extreme damage to the tissues of the gut. It is concluded that parasitism by these helminths is an important mortality factor in the chicks and a major cause of population stability—an equilibrium between death in the older age classes and replacement by surviving young.

Maternal Age as a Risk Factor for Wheezing Lower Respiratory Illnesses in the First Year of Life

1992 ◽  
Vol 136 (10) ◽  
pp. 1258-1268 ◽  
Author(s):  
Femando D. Martinez ◽  
Anne L. Wright ◽  
Catharine J. Holberg ◽  
Wayne J. Morgan ◽  
Lynn M. Taussig
Keyword(s):  
Risk Factor ◽  
Maternal Age ◽  
First Year ◽  
Respiratory Illnesses ◽  
First Year Of Life

The Development of Swallowing Respiratory Coordination

2009 ◽  
Vol 18 (1) ◽  
pp. 19-24
Author(s):  
Maggie-Lee Huckabee
Keyword(s):  
Cortical Activation ◽  
First Year ◽  
Healthy Children ◽  
Nasal Airflow ◽  
Single Session ◽  
Primary Finding ◽  
Patterns Of Behavior ◽  
Cortical Modulation ◽  
First Year Of Life ◽  
Swallowing Apnea

Abstract Research exists that evaluates the mechanics of swallowing respiratory coordination in healthy children and adults as well and individuals with swallowing impairment. The research program summarized in this article represents a systematic examination of swallowing respiratory coordination across the lifespan as a means of behaviorally investigating mechanisms of cortical modulation. Using time-locked recordings of submental surface electromyography, nasal airflow, and thyroid acoustics, three conditions of swallowing were evaluated in 20 adults in a single session and 10 infants in 10 sessions across the first year of life. The three swallowing conditions were selected to represent a continuum of volitional through nonvolitional swallowing control on the basis of a decreasing level of cortical activation. Our primary finding is that, across the lifespan, brainstem control strongly dictates the duration of swallowing apnea and is heavily involved in organizing the integration of swallowing and respiration, even in very early infancy. However, there is evidence that cortical modulation increases across the first 12 months of life to approximate more adult-like patterns of behavior. This modulation influences primarily conditions of volitional swallowing; sleep and naïve swallows appear to not be easily adapted by cortical regulation. Thus, it is attention, not arousal that engages cortical mechanisms.

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