Does baseline corticosterone influence inter-annual apparent survival of the Thorn-tailed Rayadito?

2020 ◽  
Author(s):  
Verónica Quirici ◽  
Esteban Botero-Delgadillo ◽  
Paulina González-Gómez ◽  
Pamela Espíndola-Hernández ◽  
Brayan Zambrano ◽  
...  
Keyword(s):  
Survival Probability ◽  
Survival Models ◽  
Mark Recapture ◽  
Annual Survival ◽  
Probability Of Survival ◽  
Long Term Study ◽  
Lower Baseline ◽  
Capture Recapture ◽  
Two Populations

Abstract Background: Many studies have attempted to link variation in corticosterone (Cort), the primary glucocorticoid (GC) in birds, with reproductive output, however the consequences of variation in Cort levels on survival probability have been relatively less explored. When considering baseline Cort and survival probability, two hypotheses have been proposed, the cort-fitness hypothesis and the cort-activity hypothesis. Notwithstanding a few exceptions, studies have generally however shown no relationship between levels of baseline Cort and the probability of survival. Methods: With the aim of increasing our understanding of the effect of baseline Cort on survival probability we utilized mark-recapture data from a long-term study (eight years of capture-mark-recapture) of the Thorn-tailed Rayadito ( Aphrastura spinicauda ), fitting different survival models with and without baseline Cort levels as covariates. Secondly, because the two populations in our study have different values of baseline Cort, we evaluated whether the association between baseline Cort and apparent inter-annual survival probability varied in relation to these two populations. Results: In the high latitude population (the population with lower baseline Cort levels), we observed a quadratic (inverted U-shape) relationship between baseline Cort levels and inter-annual survival probability; in the low latitude population, baseline Cort had no apparent effect on inter-annual survival probability. Conclusions: Because of the quadratic relationship, a relationship that only can be observed with long-term data, our approach emphasizes the importance of using a capture-recapture model. In addition, because the effect of baseline Cort on survival probability was found to be context-dependent, our work also highlights the importance of comparing different populations.

Nest cameras do not affect nest survival in a meadow-nesting shorebird

2020 ◽  
pp. 1-10
Author(s):  
VOLKER SALEWSKI ◽  
LUIS SCHMIDT
Keyword(s):  
Nest Survival ◽  
Bird Species ◽  
Conservation Strategies ◽  
Survival Models ◽  
Northern Germany ◽  
Term Study ◽  
Long Term Study ◽  
Limosa Limosa ◽  
Study Sites

Summary Identifying the fate of birds’ nests and the causes of breeding failure is often crucial for the development of conservation strategies for threatened species. However, collecting these data by repeatedly visiting nests might itself contribute to nest failure or bias. To solve this dilemma, automatic cameras have increasingly been used as a time-efficient means for nest monitoring. Here, we consider whether the use of cameras itself may influence hatching success of nests of the Black-tailed Godwit Limosa limosa at two long-term study sites in northern Germany. Annually between 2013 and 2019, cameras were used to monitor godwit nests. In 2014 and 2019, nests were randomly equipped with cameras or not, and nest survival checked independently of the cameras. Nest-survival models indicated that survival probabilities varied between years, sites and with time of the season, but were unaffected by the presence of cameras. Even though predation is the main cause of hatching failure in our study system, we conclude that predators did not learn to associate cameras with food either when the cameras were initially installed or after they had been used for several years. Cameras were thus an effective and non-deleterious tool to collect data for conservation in this case. As other bird species may react differently to cameras at their nests, and as other sets of predators may differ in their ability to associate cameras with food, the effect of cameras on breeding success should be carefully monitored when they are used in a new study system.

Demography of the San Francisco Gartersnake in Coastal San Mateo County, California

2011 ◽  
Vol 2 (1) ◽  
pp. 41-48 ◽  
Author(s):  
Brian J. Halstead ◽  
Glenn D. Wylie ◽  
Melissa Amarello ◽  
Jeffrey J. Smith ◽  
Michelle E. Thompson ◽  
...  
Keyword(s):  
San Francisco ◽  
Survival Rates ◽  
Thamnophis Sirtalis ◽  
Annual Survival ◽  
Coastal Prairie ◽  
Probability Of Survival ◽  
Annual Probability ◽  
The Status ◽  
San Mateo County

Abstract The San Francisco gartersnake Thamnophis sirtalis tetrataenia has been federally listed as endangered since 1967, but little demographic information exists for this species. We examined the demography of a San Francisco gartersnake population on approximately 213 ha of California coastal prairie in San Mateo County, California, from 2007 to 2010. The best-supported mark–recapture model indicated annual variation in daily capture probabilities and annual survival rates. Abundance increased throughout the study period, with a mean total population from 2008 to 2010 of 443 (95% CI  =  313–646) individuals. Annual survival was slightly greater than that of most other gartersnakes, with an annual probability of survival of 0.78 (0.55–0.95) in 2008–2009 and 0.75 (0.49–0.93) in 2009–2010. Mean annual per capita recruitment rates were 0.73 (0.02–2.50) in 2008–2009 and 0.47 (0.02–1.42) in 2009–2010. From 2008 to 2010, the probability of an increase in abundance at this site was 0.873, with an estimated increase of 115 (−82 to 326) individuals. The estimated population growth rate in 2008–2009 was 1.52 (0.73–3.29) and in 2009–2010 was 1.21 (0.70–2.17). Although this population is probably stable or increasing in the short term, long-term studies of the status of the San Francisco gartersnake at other sites are required to estimate population trends and to elucidate mechanisms that promote the recovery of this charismatic member of our native herpetofauna.

scholarly journals Survival of Brown Boobies (Sula Leucogaster) at Johnston Atoll: A Long-Term Study

The Auk ◽  
2003 ◽  
Vol 120 (3) ◽  
pp. 811-817
Author(s):  
Jon S. Beadell ◽  
E. A. Schreiber ◽  
Ralph W. Schreiber ◽  
Gary A. Schenk ◽  
Paul F. Doherty
Keyword(s):  
Southern Oscillation ◽  
Adult Survival ◽  
Term Study ◽  
Environmental Fluctuation ◽  
Mark Recapture ◽  
Invariant Model ◽  
Long Term Study ◽  
Sula Leucogaster ◽  
Time Invariant

Abstract Survival of Brown Boobies (Sula leucogaster) at Johnston Atoll was examined over a 17-year period using capture-mark-recapture analysis. Annual adult survival was estimated to be 0.90 ± 0.01 (SE). Variation in survival did not correspond to either local environmental fluctuation or more widespread disturbances associated with El Niño-Southern Oscillation events, and a time-invariant model of survival was best supported by our data. Absence of major oceanographic anomalies in the immediate vicinity of Johnston Atoll may contribute to relatively high and invariant survival in Brown Boobies.

Clone-selection and optimal rates of mutation

1973 ◽  
Vol 10 (4) ◽  
pp. 728-738 ◽  
Author(s):  
Ilan Eshel
Keyword(s):  
Survival Probability ◽  
Branching Processes ◽  
Intrinsic Rate ◽  
Term Survival ◽  
Probability Of Survival ◽  
Environmental Deterioration ◽  
Multitype Branching Processes ◽  
Quantitative Results ◽  
Biological Problem

The paper employs methods of multitype branching processes to evaluate the probability of survival of mutable clones under environmental conditions which are unfavorable to the original parent of the clone. When other factors are taken to be constant, the long-term survival probability of a clone is implicitly demonstrated as a function of the intrinsic rate of mutation carried by this clone. The existence of a mutation rate which maximizes clone survival probability is shown and the effects of environmental deterioration on this optimal rate are studied. Finally, rigorous quantitative results are obtained for the classical situation of a Poisson distribution of offspring numbers. These results are then applied to the biological problem of indirect selection (Eshel (1972)).

scholarly journals Direct evidence of the impact of longline fishery on mortality in the Black-footed Albatross Phoebastria nigripes

2012 ◽  
Vol 23 (1) ◽  
pp. 25-35 ◽  
Author(s):  
JEAN-DOMINIQUE LEBRETON ◽  
SOPHIE VÉRAN
Keyword(s):  
Survival Probability ◽  
Direct Evidence ◽  
Strong Impact ◽  
Longline Fishery ◽  
Vertebrate Species ◽  
Probability Of Survival ◽  
Annual Probability ◽  
Capture Recapture ◽  
Longline Fisheries ◽  
The Impact

SummaryThe incidental bycatch of seabirds in longline fisheries is one of the most striking examples of diffuse and incidental impact of human activities on vertebrate species. While there are various types of evidence of a strong impact of longline fisheries on seabirds, in particular albatrosses, the incidental bycatch mortality has never been directly linked to estimates of bycatch derived from on-board surveys. We develop a capture-recapture analysis which relates the annual probability of survival in the Black-Footed Albatross to the estimated absolute bycatch. By converting the absolute bycatch into an estimate relative to population size and using the theory of exploited populations, we show that survival probability decreases linearly with bycatch, and that the bycatch is underestimated by at least 50%, confirming suspicions based on reviews of the bycatch survey procedures, and raising further concerns about the impact of longline fisheries on seabirds.

Comparing wild and reintroduced populations of the threatened orchid Diuris fragrantissima (Orchidaceae) in south-eastern Australia

2018 ◽  
Vol 66 (7) ◽  
pp. 459
Author(s):  
Michael Duncan ◽  
Paul D. Moloney
Keyword(s):  
Annual Survival ◽  
Multinomial Models ◽  
Emergent Plants ◽  
Strong Trend ◽  
Eastern Australia ◽  
Species Lists ◽  
In The Wild ◽  
Capture Recapture ◽  
Reintroduced Population

Orchids have high rates of speciation and extinction, and are over-represented on threatened species lists. Reintroductions are being used with increasing frequency as an important tool for threatened orchid recovery. The ultimate aim of these reintroductions is to create a self-sustaining population that will reduce the risk of extinction for the species. In this case study, we test the hypotheses that state transition, annual survival, and seed production rates in a reintroduced population were equivalent to those in the wild population. These hypotheses were tested using long-term demographic monitoring datasets from a wild and a reintroduced population of Diuris fragrantissima, and analysed using Bayesian multistate capture–recapture and multinomial models. The results showed that emergent plants at the reintroduction site were more likely to transition to vegetative or unobserved states, and less likely to flower in the following year, than those at the wild site. This resulted in a strong trend through time away from emergent life states at the reintroduction site. The estimated annual survival rate was >90% at the wild site, and <80% in five of the seven years at the reintroduction site. Flowering was the most frequently recorded life state at the wild site. The fate of an individual flower was not affected by site (wild or reintroduction), but an increase in rainfall increased the probability that a flower would set seed and decreased the probability that it would be browsed. The reintroduction has failed to produce a stable, sustainable, long-term population, but it has been valuable in providing information that will inform the development and improvement of future D. fragrantissima reintroductions. Improving our knowledge in these areas should increase the chances of future D. fragrantissima reintroductions being assessed as a success.

Clone-selection and optimal rates of mutation

1973 ◽  
Vol 10 (04) ◽  
pp. 728-738 ◽  
Author(s):  
Ilan Eshel
Keyword(s):  
Survival Probability ◽  
Branching Processes ◽  
Intrinsic Rate ◽  
Term Survival ◽  
Probability Of Survival ◽  
Environmental Deterioration ◽  
Multitype Branching Processes ◽  
Quantitative Results ◽  
Biological Problem

The paper employs methods of multitype branching processes to evaluate the probability of survival of mutable clones under environmental conditions which are unfavorable to the original parent of the clone. When other factors are taken to be constant, the long-term survival probability of a clone is implicitly demonstrated as a function of the intrinsic rate of mutation carried by this clone. The existence of a mutation rate which maximizes clone survival probability is shown and the effects of environmental deterioration on this optimal rate are studied. Finally, rigorous quantitative results are obtained for the classical situation of a Poisson distribution of offspring numbers. These results are then applied to the biological problem of indirect selection (Eshel (1972)).

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