scholarly journals Sex‐specific population dynamics of ocelots in Belize using open population spatial capture–recapture

Ecosphere ◽  
2019 ◽  
Vol 10 (7) ◽  
Author(s):  
Christopher B. Satter ◽  
Ben C. Augustine ◽  
Bart J. Harmsen ◽  
Rebecca J. Foster ◽  
Marcella J. Kelly
Keyword(s):  
Population Dynamics ◽  
Specific Population ◽  
Open Population ◽  
Capture Recapture

scholarly journals Sex-specific population dynamics and demography of capercaillie (Tetrao urogallus L.) in a patchy environment

2019 ◽  
Author(s):  
Ben C. Augustine ◽  
Marc Kéry ◽  
Juanita Olano Marin ◽  
Pierre Mollet ◽  
Gilberto Pasinelli ◽  
...  
Keyword(s):  
Population Dynamics ◽  
Population Trends ◽  
Tetrao Urogallus ◽  
Male Population ◽  
Specific Population ◽  
Female Population ◽  
Open Population ◽  
Species Of Conservation Concern ◽  
Conservation Concern ◽  
Scr Model

AbstractModeling the population dynamics of patchily distributed species is a challenge, particularly when inference must be based on incomplete and small data sets such as those from most species of conservation concern. Open population spatial capture-recapture (SCR) models are ideally suited to quantify population trends, but have seen only limited use since their introduction.To investigate population trend and sex-specific population dynamics, we applied an open SCR model to a capercaillie (Tetrao urogallus) population in Switzerland living in eight distinct forest patches totalling 22 km2 within a region of 908 km2. The population was surveyed using genetic sampling of scat in 2009, 2012 and 2015. We fit an open SCR model with sex-specific detection and population dynamics parameters while accounting for the patchy distribution of habitat and the uncertainty introduced by observing the population in three years only.Between 2009 and 2015, a total of 143 males, 112 females and 4 individuals of uncertain sex were detected. The annual per capita recruitment rate was estimated at 0.115 (SE 0.0144) for males and 0.127 (0.0168) for females. The estimated annual survival probability for males was 0.758 (0.0241) and 0.707 (0.0356) for females. The population trajectory implied by these survival and recruitment estimates was a decline of 2% per year; however, the sex specificity of the model revealed a decline in the male population only, with no evidence of decline in the female population. Further, the population decline observed in males was explained by the demography of just two of the eight patches.Using a customized open population SCR model, we determined that the endangered capercaillie in our Swiss study area had a stable female population and a declining male population, with the male decline due to population dynamics in a subset of the study area. Our study highlights the flexibility of open population SCR models for assessing population trajectories through time and across space and emphasizes the desirability of estimating sex-stratified population trends especially in species of conservation concern.

scholarly journals On the Estimation of Dispersal and Movement of Birds

The Condor ◽  
2004 ◽  
Vol 106 (4) ◽  
pp. 720-731 ◽  
Author(s):  
William L. Kendall ◽  
James D. Nichols
Keyword(s):  
Robust Design ◽  
Nonlinear Dynamic ◽  
Detection Probability ◽  
Cross Correlation ◽  
Statistical Methodology ◽  
Open Population ◽  
Abundance Estimates ◽  
Capture Recapture ◽  
Over Time

Abstract The estimation of dispersal and movement is important to evolutionary and population ecologists, as well as to wildlife managers. We review statistical methodology available to estimate movement probabilities. We begin with cases where individual birds can be marked and their movements estimated with the use of multisite capture-recapture methods. Movements can be monitored either directly, using telemetry, or by accounting for detection probability when conventional marks are used. When one or more sites are unobservable, telemetry, band recoveries, incidental observations, a closed- or open-population robust design, or partial determinism in movements can be used to estimate movement. When individuals cannot be marked, presence-absence data can be used to model changes in occupancy over time, providing indirect inferences about movement. Where abundance estimates over time are available for multiple sites, potential coupling of their dynamics can be investigated using linear cross-correlation or nonlinear dynamic tools. Sobre la Estimación de la Dispersión y el Movimiento de las Aves Resumen. La estimación de la dispersión y el movimiento es importante para los ecó logos evolutivos y de poblaciones, así como también para los encargados del manejo de vida silvestre. Revisamos la metodología estadística disponible para estimar probabilidades de movimiento. Empezamos con casos donde aves individuales pueden ser marcadas y sus movimientos estimados con el uso de métodos de captura-repactura para múltiples sitios. Los movimientos pueden ser monitoreados ya sea directamente, usando telemetría o teniendo en cuenta las probabilidades de detección cuando se usan marcas convencionales. Cuando uno o más sitios no pueden ser observados, se puede estimar el movimiento usando telemetría, recuperación de anillos, observaciones circunstanciales, un diseño poblacional robusto cerrado o abierto, o determinismo parcial de los movimientos. Cuando los individuos no pueden ser marcados, se pueden usar datos de presencia-ausencia para modelar los cambios en el tiempo de la ocupación, brindando inferencias indirectas sobre los movimientos. Cuando las estimaciones de abundancia a lo largo del tiempo están disponibles para varios sitios, se puede investigar la interrelación potencial de sus dinámicas usando correlaciones cruzadas lineales o herramientas para dinámica no lineal.

scholarly journals Estimating abundance with interruptions in data collection using open population spatial capture–recapture models

Ecosphere ◽  
2020 ◽  
Vol 11 (7) ◽  
Author(s):  
Cyril Milleret ◽  
Pierre Dupont ◽  
Joseph Chipperfield ◽  
Daniel Turek ◽  
Henrik Brøseth ◽  
...  
Keyword(s):  
Data Collection ◽  
Open Population ◽  
Capture Recapture

scholarly journals Breeding transients in capture–recapture modeling and their consequences for local population dynamics

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Daniel Oro ◽  
Daniel F. Doak
Keyword(s):  
Growth Rate ◽  
Population Dynamics ◽  
Population Growth ◽  
Population Growth Rate ◽  
Local Population ◽  
Environmental Stochasticity ◽  
Adult Survival ◽  
Local Survival ◽  
First Reproduction ◽  
Capture Recapture

Abstract Standard procedures for capture–mark–recapture modelling (CMR) for the study of animal demography include running goodness-of-fit tests on a general starting model. A frequent reason for poor model fit is heterogeneity in local survival among individuals captured for the first time and those already captured or seen on previous occasions. This deviation is technically termed a transience effect. In specific cases, simple, uni-state CMR modeling showing transients may allow researchers to assess the role of these transients on population dynamics. Transient individuals nearly always have a lower local survival probability, which may appear for a number of reasons. In most cases, transients arise due to permanent dispersal, higher mortality, or a combination of both. In the case of higher mortality, transients may be symptomatic of a cost of first reproduction. A few studies working at large spatial scales actually show that transients more often correspond to survival costs of first reproduction rather than to permanent dispersal, bolstering the interpretation of transience as a measure of costs of reproduction, since initial detections are often associated with first breeding attempts. Regardless of their cause, the loss of transients from a local population should lower population growth rate. We review almost 1000 papers using CMR modeling and find that almost 40% of studies fitting the searching criteria (N = 115) detected transients. Nevertheless, few researchers have considered the ecological or evolutionary meaning of the transient phenomenon. Only three studies from the reviewed papers considered transients to be a cost of first reproduction. We also analyze a long-term individual monitoring dataset (1988–2012) on a long-lived bird to quantify transients, and we use a life table response experiment (LTRE) to measure the consequences of transients at a population level. As expected, population growth rate decreased when the environment became harsher while the proportion of transients increased. LTRE analysis showed that population growth can be substantially affected by changes in traits that are variable under environmental stochasticity and deterministic perturbations, such as recruitment, fecundity of experienced individuals, and transient probabilities. This occurred even though sensitivities and elasticities of these parameters were much lower than those for adult survival. The proportion of transients also increased with the strength of density-dependence. These results have implications for ecological and evolutionary studies and may stimulate other researchers to explore the ecological processes behind the occurrence of transients in capture–recapture studies. In population models, the inclusion of a specific state for transients may help to make more reliable predictions for endangered and harvested species.

scholarly journals Open population maximum likelihood spatial capture‐recapture

Biometrics ◽  
2019 ◽  
Vol 75 (4) ◽  
pp. 1345-1355 ◽  
Author(s):  
Richard Glennie ◽  
David L. Borchers ◽  
Matthew Murchie ◽  
Bart J. Harmsen ◽  
Rebecca J. Foster
Keyword(s):  
Maximum Likelihood ◽  
Open Population ◽  
Capture Recapture ◽  
Population Maximum

scholarly journals The influence of spatio-temporal resource fluctuations on insular rat population dynamics

2011 ◽  
Vol 279 (1729) ◽  
pp. 767-774 ◽  
Author(s):  
James C. Russell ◽  
Lise Ruffino
Keyword(s):  
Population Dynamics ◽  
Resource Availability ◽  
Rattus Rattus ◽  
Resource Subsidies ◽  
Driven Systems ◽  
Resource Pulses ◽  
State Capture ◽  
Main Driver ◽  
Capture Recapture ◽  
Spatio Temporal

Local spatio-temporal resource variations can strongly influence the population dynamics of small mammals. This is particularly true on islands which are bottom-up driven systems, lacking higher order predators and with high variability in resource subsidies. The influence of resource fluctuations on animal survival may be mediated by individual movement among habitat patches, but simultaneously analysing survival, resource availability and habitat selection requires sophisticated analytical methods. We use a Bayesian multi-state capture–recapture model to estimate survival and movement probabilities of non-native black rats ( Rattus rattus ) across three habitats seasonally varying in resource availability. We find that survival varies most strongly with temporal rainfall patterns, overwhelming minor spatial variation among habitats. Surprisingly for a generalist forager, movement between habitats was rare, suggesting individuals do not opportunistically respond to spatial resource subsidy variations. Climate is probably the main driver of rodent population dynamics on islands, and even substantial habitat and seasonal spatial subsidies are overwhelmed in magnitude by predictable annual patterns in resource pulses. Marked variation in survival and capture has important implications for the timing of rat control.

Exploring the population dynamics of winter skate (Leucoraja ocellata) in the Georges Bank region using a statistical catch-at-age model incorporating length, migration, and recruitment process errors

2010 ◽  
Vol 67 (5) ◽  
pp. 774-792 ◽  
Author(s):  
M. G. Frisk ◽  
S. J.D. Martell ◽  
T. J. Miller ◽  
K. Sosebee
Keyword(s):  
Population Dynamics ◽  
Information Criterion ◽  
Adult Mortality ◽  
Population Increase ◽  
Observation Error ◽  
Georges Bank ◽  
Recruitment Process ◽  
Open Population ◽  
Age Model ◽  
Parsimonious Models

Winter skate ( Leucoraja ocellata ) of all length classes increased dramatically in abundance on Georges Bank in the 1980s following the decline of many groundfish species. We present a full population model of winter skate to better understand the population dynamics of the species and elucidate the mechanisms underlying their increase in abundance in the 1980s. Specifically, we developed four statistical catch-at-age models incorporating length-frequency data with the following model structures: (i) observation error only (base model R1); (ii) observation and recruitment process errors (model R2); (iii) adult migration modeled as a random walk in adult mortality (model R3); and (iv) observation and recruitment process errors and adult migration (model R4). Akaike’s information criterion values indicated that models R3 and R4, which both included adult migration, were the most parsimonious models. This finding strongly suggests that the winter skate population increase on Georges Bank in the 1980s was not solely a result of increases in recruitment but likely involved adult migration (i.e., it is an open population). Finally, recent predicted fishing mortalities exceeded FMSY for all models.

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