New insight on survivorship of female chamois (Rupicapra rupicapra) from observation of marked animals

1994 ◽  
Vol 72 (4) ◽  
pp. 591-597 ◽  
Author(s):  
A. Loison ◽  
J. M. Gaillard ◽  
H. Houssin

A population of about 1500 chamois (Rupicapra rupicapra) was monitored in the French Alps between 1985 and 1991 by observing individually marked animals. Data on resighting of marked females were analyzed using capture–recapture models. Resighting probabilities were time dependent and survival rates were age dependent. The annual survival rate was low in juveniles (0.58) and high in adults (0.96). Maturing animals (1.5–3.5 years old) had lower survival rates (0.91) than adults. Older age-classes exhibited no significant decline in survival rates. Survival patterns are compared with those from a previous study in New Zealand, and biological and methodological differences between the two studies are discussed.

2006 ◽  
Vol 274 (1608) ◽  
pp. 407-415 ◽  
Author(s):  
Jason D Baker ◽  
Paul M Thompson

Estimates of variability in pinniped survival rates are generally based on observations at single sites, so it is not certain whether observed rates represent the whole population. Here, we provide a comprehensive analysis of spatio-temporal variation in age-specific survival rates for endangered Hawaiian monk seals ( Monachus schauinslandi ) based on capture–recapture analyses of more than 85% of the pups weaned in this population over the last two decades. Uniquely, these data have been collected from six subpopulations, encompassing all major breeding sites across its 1800 km long core range. Analyses of individual subpopulations revealed similar patterns in age-specific survival, characterized by the relatively low survival rates from weaning to 2 years of age, intermediate rates to 4 years of age, and then by relatively high ‘mature’ survival rates until 17 years of age, after which a senescent decline was observed. Juvenile, subadult and adult survival rates all varied significantly over time. Trends in survival among subpopulations were coherent with their relative geographical positions, suggesting regional structuring and connectedness within the archipelago. Survival rates for different age classes tended to be positively correlated, suggesting that similar factors may influence the survival for seals of all ages.


2017 ◽  
Vol 28 (1) ◽  
pp. 145-156 ◽  
Author(s):  
YANFANG LI ◽  
XINPING YE ◽  
MIN WANG ◽  
XIA LI ◽  
RONG DONG ◽  
...  

SummaryA reintroduction project for the endangered Crested Ibis Nipponia nippon was conducted in Ningshan County (Shaanxi Province) on May 31, 2007. Post-release monitoring of the survival of the reintroduced population was carried out extensively from 2008 to 2015. Data collected over eight years after release were used to estimate the annual survival rate for different cohorts using a Cormack-Jolly-Seber model with capture-recapture data. The mean annual survival rates for all individuals were estimated to be 0.738 (95% CI: 0.547–0.801) and 0.752 (95% CI: 0.478–0.887) for released birds. For different age classes in the recipient population, the survival rates were estimated to be 0.384 (95% CI: 0.277–0.504), 0.853 (95% CI: 0.406–0.978), and 0.812 (95% CI: 0.389–0.950) for yearlings, juveniles and adults, respectively. The higher mortality for yearlings has greatly decreased the survival rate and our focal population was indeed sensitive to changes in yearling survival. Therefore, effective protection of yearlings was crucial to population persistence, as well as to juveniles and adults. The large proportion of mature individuals in our focal population indicated a gradually growing population. There was a slight bias towards males in the adult sex ratio with the increase of wild-born offspring, but it was not statistically significant. Therefore, we conclude that the primary goal of establishing a self-sustaining population of the Crested Ibis in part of their historical range has been achieved. Finally, we discuss factors affecting the survival of the reintroduced population and we propose some changes for future management of endangered species.


1987 ◽  
Vol 14 (4) ◽  
pp. 491 ◽  
Author(s):  
N Gilbert ◽  
K Myers ◽  
BD Cooke ◽  
JD Dunsmore ◽  
PJ Fullagar ◽  
...  

Shot samples of rabbits were collected over several years at 11 sites in Australia and one in New Zealand. At any one site, pregnancy rates and litter sizes vary both with age of mother and with time of year. Few rabbits become pregnant before the age of 19 weeks; pregnancy rate increases until the full adult rate is achieved about 27 weeks old. Litter size is also affected by age, adult litter size being reached by females at about 43 weeks old. Rates and timing of reproduction vary greatly from site to site in response to local conditions. The annual production of young per fully adult female is highest at Wairarapa, N.Z. (53 young) and lowest in the semiarid (17) and subalpine (15) environments. At six of the sites cohorts of marked rabbits provided estimates of seasonal survival rates; survival improves with age but becomes relatively constant in rabbits aged more than 24 weeks; survival patterns differ between sites. Life tables were constructed combining the information on reproduction and survival. Their possible usefulness is discussed.


2018 ◽  
Vol 45 (2) ◽  
pp. 155 ◽  
Author(s):  
Chifuyu Horikoshi ◽  
Phil F. Battley ◽  
Edward O. Minot

Context The risk of secondary poisoning to native fauna during pest control operations is an issue of global concern. In New Zealand, non-target impacts during sodium fluoroacetate (1080) operations are particularly contentious. 1080 is used extensively for pest control for conservation, bovine tuberculosis control, and in plantation forestry for seedling protection from herbivores. The endemic New Zealand falcon (Falco novaeseelandiae) breeds in Kaingaroa forest, an intensively managed pine plantation where regular 1080 poison operations are conducted; however, causes of mortality and risks of secondary poisoning by 1080 are not well documented. Aims We aimed to investigate mortality and survival of adult falcons with an emphasis on assessing the possible role of 1080 poisoning in annual mortality. Methods Using radio-telemetry and visual observations, we monitored 37 marked adult falcons before and after 1080 operations in 2013–14 (16 through carrot-bait and 21 through cereal-bait operations) and assessed mortality causes through post-mortem examinations. Using Program MARK, the annual survival rates for adults and independent juveniles were estimated from long-term banding data (2003–2014). Key results Survival of falcons was high through both cereal-bait (21/21) and carrot-bait (15/16) 1080 operations (overall 95% CI for survival = 84–100%). The exception was a radio-tagged male that died of unknown causes within a fortnight of an operation and tested negative for 1080 residues. Three falcons were depredated by introduced mammals. One falcon was found dead in an emaciated condition but evidently died from head injury through Australasian magpie (Cracticus tibicen) attack. The annual survival rate of falcons estimated from long-term banding was 80 ± 6.0% (mean ± s.e.) for adults and 29 ± 0.1% for juveniles. Conclusions No adult falcon death was attributable to 1080 poisoning in this study. Identifiable mortalities were attributable to depredation by introduced mammals and an injury from an Australasian magpie. The annual survival rate of Kaingaroa falcons was comparable to those of other raptor species worldwide. Implications The risk to adult falcons from 1080 secondary poisoning is likely low. Whether this is also true for juveniles requires further study.


2019 ◽  
Vol 76 (11) ◽  
pp. 2027-2034 ◽  
Author(s):  
Paul E. Kanive ◽  
Jay J. Rotella ◽  
Salvador J. Jorgensen ◽  
Taylor K. Chapple ◽  
James E. Hines ◽  
...  

For species that exist at low abundance or are otherwise difficult to study, it is challenging to estimate vital rates such as survival and fecundity and common to assume that survival rates are constant across ages and sexes. Population assessments based on overly simplistic vital rates can lead to erroneous conclusions. We estimated sex- and length-based annual apparent survival rates for white sharks (Carcharodon carcharias). We found evidence that annual apparent survival differed over ontogeny in a system with competitive foraging aggregations, from 0.63 (standard error (SE) = 0.08) for newly recruiting subadults to 0.95 (SE = 0.02) for the largest sharks. Our results reveal a potential challenge to ontogenetic recruitment in a long-lived, highly mobile top marine predator, as survival rates for subadult white sharks may be lower than previously assumed. Alternatively, younger and competitively inferior individuals may be forced to permanently emigrate from primary foraging sites. This study provides new methodology for estimating apparent survival as a function of diverse covariates by capture–recapture study, including when sex assignment is uncertain.


2018 ◽  
Vol 9 (1) ◽  
pp. 90-99 ◽  
Author(s):  
Tomas Bird ◽  
Jarod Lyon ◽  
Simon Wotherspoon ◽  
Charles Todd ◽  
Zeb Tonkin ◽  
...  

The Auk ◽  
2004 ◽  
Vol 121 (4) ◽  
pp. 1199-1207
Author(s):  
Rita Covas ◽  
Charles R. Brown ◽  
Mark D. Anderson ◽  
Mary Bomberger Brown

Abstract We used capture-recapture analyses to describe juvenile and adult survival from 1993 to 2001 in a population of Sociable Weavers (Philetairus socius), a colonial, cooperatively breeding passerine of southern Africa. We examined temporal variation in survival and the role that the breeding season's length and environmental factors play in determining survival patterns in the population. Annual survival probability (mean ± SE) was 0.66 ± 0.02. In contrast to most passerines, juveniles and adults had similar survival probabilities; survival rates did not vary significantly between years. We found no relationship among temperature, rainfall, and survival. Relatively high survival rates in Sociable Weavers probably result from a benign climate and easy access to food in winter. Juvenile survival may also be enhanced by prolonged parental care and delayed dispersal.


2000 ◽  
Vol 57 (1) ◽  
pp. 247-253 ◽  
Author(s):  
Carl J Schwarz ◽  
Wayne T Stobo

We use a longitudinal capture-recapture study from resightings of grey seals (Halichoerus gryprus) branded as young on Sable Island to estimate (i) the juvenile survival rate from the time of branding to age 4, (ii) the yearly adult survival rate from age 4 to age 9, and (iii) the age-specific pupping probabilities, i.e., the probability that a seal will first give birth at each age. The estimated juvenile survival rate from branding (just after weaning) to age 4 ranged from 70 to 80%; however, the lower values are known to be biased low because the study was terminated early. The estimated yearly adult survival rates for ages 4-9 ranged from 0.88 to 0.92·year-1. The estimated probabilities of first giving birth to a young seal (pupping) at ages 4-9 are 0.28, 0.41, 0.18, 0.06, 0.05, and 0.02, respectively, and the estimated average age of first pupping is 5.2 years.


1998 ◽  
Vol 76 (7) ◽  
pp. 1335-1343 ◽  
Author(s):  
Vanessa A Sorensen ◽  
Roger A Powell

Capture-recapture, radiotelemetry (on a monthly and a yearly basis), and age-distribution methods were used to estimate annual survival rates for black bears (Ursus americanus) in the southern Appalachians from 1981 to 1996. Using capture-recapture data, the Jolly-Seber estimator calculated the annual survival rate for all bears over all years to be 0.64 ± 0.04 (mean ± SE). Because of small sample sizes, this method did not produce yearly estimates or allow separation of the data into age or sex classes. Both the Kaplan-Meier estimator (using monthly telemetry data) and the percent survival estimator (using yearly telemetry data) computed an overall annual survival rate of 0.76 ± 0.04. Survival rates for the early years of the study (1981-1987) were significantly lower than in the late years (1988-1996). No significant difference in survival rate was detected between the sexes or among age-classes. Because it is difficult to capture and recapture large numbers of animals, radiotelemetry methods are preferable for large mammals such as black bears. If bears wear their collars for at least a year, calculating survival from yearly telemetry data provides a good estimate of bear survival. Using monthly telemetry data, however, provided the most detailed understanding of bear survival. Survival estimates produced by the age-distribution method were unreliable.


2007 ◽  
Vol 34 (1) ◽  
pp. 125-145 ◽  
Author(s):  
Alan Sangster

This paper considers the printing of Pacioli's Summa de Arithmetica, Geometria, Proportioni et Proportionalita (Summa) in 1494. In particular, it attempts to answer the question, how many copies of Summa were printed in 1494? It does so through consideration of the printing process, the printer of Summa, the size of the book, survival rates of other “serious” books of the period, and the dates it contains revealing when parts of it were completed. It finds that more copies were published than was previously suggested, and that the survival rate of copies has probably as much to do with the manner in which it was treated once acquired as in the number of copies printed.


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