Using experimental reintroductions to resolve the roles of habitat quality and metapopulation dynamics on patch occupancy in fragmented landscapes.

Declines of species in fragmented landscapes can potentially be reversed either by restoring connectivity or restoring local habitat quality. Models fitted to snapshot occupancy data can be used to predict the effectiveness of these actions. However, such inferences can be misleading if the reliability of the habitat and landscape metrics used is unknown. The only way to unambiguously resolve the roles of habitat quality and metapopulation dynamics is to conduct experimental reintroductions to unoccupied patches so that habitat quality can be measured directly from data on vital rates. We, therefore, conducted a 15-year study that involved reintroducing a threatened New Zealand bird to unoccupied forest fragments to obtain reliable data on their habitat quality and reassess initial inferences made by modeling occupancy against habitat and landscape metrics. Although reproductive rates were similar among fragments, subtle differences in adult survival rates resulted in λ (finite rate of increase) estimations of <0.9 for 9 of the 12 fragments that were previously unoccupied. This was the case for only 1 of 14 naturally occupied fragments. This variation in λ largely explained the original occupancy pattern, reversing our original conclusion from occupancy modeling that this occupancy pattern was isolation driven and suggesting that it would be detrimental to increase connectivity without improving local habitat quality. These results illustrate that inferences from snapshot occupancy should be treated with caution and subjected to testing through experimental reintroductions in selected model systems.

Uso de Reintroducciones Experimentales para Determinar las Funciones de la Calidad delHábitat y las Dinámicas Metapoblacionales en la Ocupación de Paisajes Fragmentados Resumen La declinación de las especies en paisajes fragmentados tiene el potencial de ser revertida mediante la restauración de la conectividad o de la calidad del hábitat. Se pueden utilizar los modelos ajustados a los datos de ocupación instantánea para predecir la efectividad de estas acciones. Sin embargo, estas inferencias pueden ser engañosas si se desconoce la confiabilidad de las medidas usadas para el hábitat y el paisaje. La única manera de determinar inequívocamente las funciones de la calidad del hábitat y de las dinámicas metapoblacionales es mediante la realización de reintroducciones experimentales en los fragmentos no ocupados, de tal manera que se puede medir directamente la calidad del hábitat a partir de los datos de las tasas vitales. Por lo tanto, realizamos un estudio de 15 años que involucró la reintroducción de un ave neozelandesa amenazada en fragmentos no ocupados de bosque para así obtener datos confiables de la calidad del hábitat y reevaluar las inferencias iniciales hechas por los modelos de ocupación en relación con las medidas de hábitat y paisaje. Aunque las tasas de reproducción fueron similares entre los fragmentos, algunas diferencias sutiles en las tasas de supervivencia de los adultos resultaron en estimaciones λ (una tasa finita de incremento) <0.9 en nueve de los doce fragmentos que no estaban ocupados previamente. Este fue el caso para uno solo de los 14 fragmentos ocupados naturalmente. Esta variación λ explicó en su mayoría el patrón original de ocupación, revirtiendo nuestra conclusión original obtenida del modelo de ocupación de que este patrón estuvo causado por el aislamiento y sugiriendo que sería perjudicial incrementar la conectividad sin mejorar la calidad del hábitat local. Estos resultados muestran que las inferencias a partir de la ocupación instantánea deberían abordarse con cautela y estar sujetas al análisis mediante reintroducciones experimentales en sistemas modelados selectos.

Bridging gaps in demographic analysis with phylogenetic imputation.

Phylogenetically informed imputation methods have rarely been applied to estimate missing values in demographic data but may be a powerful tool for reconstructing vital rates of survival, maturation, and fecundity for species of conservation concern. Imputed vital rates could be used to parameterize demographic models to explore how populations respond when vital rates are perturbed. We used standardized vital rate estimates for 50 bird species to assess the use of phylogenetic imputation to fill gaps in demographic data. We calculated imputation accuracy for vital rates of focal species excluded from the data set either singly or in combination and with and without phylogeny, body mass, and life-history trait data. We used imputed vital rates to calculate demographic metrics, including generation time, to validate the use of imputation in demographic analyses. Covariance among vital rates and other trait data provided a strong basis to guide imputation of missing vital rates in birds, even in the absence of phylogenetic information. Mean NRMSE for null and phylogenetic models differed by <0.01 except when no vital rates were available or for vital rates with high phylogenetic signal (Pagel's λ > 0.8). In these cases, including body mass and life-history trait data compensated for lack of phylogenetic information: mean normalized root mean square error (NRMSE) for null and phylogenetic models differed by <0.01 for adult survival and <0.04 for maturation rate. Estimates of demographic metrics were sensitive to the accuracy of imputed vital rates. For example, mean error in generation time doubled in response to inaccurate estimates of maturation time. Accurate demographic data and metrics, such as generation time, are needed to inform conservation planning processes, for example through International Union for Conservation of Nature Red List assessments and population viability analysis. Imputed vital rates could be useful in this context but, as for any estimated model parameters, awareness of the sensitivities of demographic model outputs to the imputed vital rates is essential.

Cerrando Brechas en los Análisis Demográficos con Imputación Filogenética Resumen Los métodos de imputación guiados filogenéticamente se han aplicado con poca frecuencia para estimar los valores faltantes en los datos demográficos, aunque pueden ser una herramienta poderosa para la reconstrucción de tasas vitales de supervivencia, maduración y fecundidad de especies de importancia para la conservación. Las tasas vitales imputadas podrían usarse para generar parámetros en los modelos demográficos para explorar cómo responden las poblaciones cuando se perturban las tasas vitales. Utilizamos estimaciones de tasas vitales estandarizadas para 50 especies de aves para analizar el uso de la imputación filogenética para llenar los vacíos en los datos demográficos. Calculamos la certeza de imputación para las tasas vitales de las especies focales excluidas del conjunto de datos por sí solas o en combinación y con y sin datos de filogenia, masa corporal y características de historia de vida. Usamos las tasas vitales imputadas para calcular las medidas demográficas, incluyendo el tiempo de generación, y así validar el uso de la imputación en los análisis demográficos. La covarianza entre las tasas vitales y otros datos de características proporcionó una base sólida para orientar la imputación de tasas vitales faltantes en las aves, incluso la ausencia de información filogenética. El NRMSE medio para los modelos nulo y filogenético difirió por <0.01 salvo cuando no hubo tasas vitales disponibles o para tasas vitales con una señal filogenética alta (λ de Pagel > 0.8). En estos casos, la inclusión de la masa corporal y las características de historia de vida compensó la falta de información filogenética: el error cuadrático medio de la raíz normalizada media (NRMSE) para los modelos nulo y filogenéticos difirió por <0.01 para la supervivencia adulta y <0.04 para la tasa de maduración. Las estimaciones de las medidas demográficas fueron sensibles a la certeza de las tasas vitales imputadas. Por ejemplo, el error medio en el tiempo generacional se duplicó en respuesta a las estimaciones imprecisas del tiempo de maduración. Las medidas y datos demográficos certeros, como el tiempo generacional, son necesarios para orientar los procesos de planeación de la conservación; por ejemplo, a través de las valoraciones de la Lista Roja de la Unión Internacional para la Conservación de la Naturaleza y los análisis de viabilidad poblacional. Las tasas vitales imputadas podrían ser útiles en este contexto, pero como para cualquier tipo de parámetro de modelo estimado, el conocimiento de las sensibilidades del rendimiento del modelo demográfico es esencial para las tasas vitales imputadas.

Another look at a good approximation of data for the distribution of COVID-19 in Cuba / Otra mirada hacia una correcta aproximación de datos para la distribución de la COVID-19 en Cuba

In the article "Adjustment of population growth curve applied to Covid-19 in Cuba", the authors propose six types of models to approximate data from the distribution of COVID-19 in Cuba, while giving a clear answer to the possible advantages of some considerations. In this paper, we study intrinsic properties of some models of growth with polynomial variable transfer that give a very good approximation of the specific data on the pandemics in Cuba by June 5, 2020. The models have the right to exist in the treatment of issues from different fields of scientific knowledge. Numerical examples are presented using CAS MATHEMATICA(AU)

En el artículo "Ajuste de curvas de crecimiento poblacional aplicadas a la COVID-19 en Cuba", los autores proponen y seriamente analizan seis tipos de modelos (logísticos y otros modelos de crecimiento) para aproximar los datos sobre la distribución de la COVID-19 en Cuba mientras plantean una clara respuesta a las posibles ventajas de algunas consideraciones. En este trabajo estudiamos las propiedades intrínsecas de algunos modelos de creciemiento con transferencia de variables polinómicas que proporcionan una muy buena aproximación de los datos específicos sobre la pandemia en Cuba antes del 5 de junio de 2020. Los modelos tienen el derecho a existir en el tratamiento de cuestiones de diferentes campos del conocimiento científico. Los ejemplos numéricos se presentan utilizando un modelo matemático para calcular los casos(AU)

Ajuste de curvas de crecimiento poblacional aplicadas a la COVID-19 en Cuba / Adjustment of population growth curve applied to COVID-19 in Cuba

Introducción: Cuba ha sido afectada por la COVID-19. Todas las provincias del país han presentado casos confirmados de la enfermedad. Se han llevado a cabo medidas por parte del gobierno y el sistema de salud, para contrarrestar el contagio de persona a persona. Es de gran ayuda contar con estimaciones de casos confirmados para las decisiones. Objetivos: Obtener predicciones para los picos de casos confirmados y cantidad total de estos para algunas provincias de Cuba y para todo el país. Material y Métodos: Estudio de tipo predictivo de curvas de crecimiento poblacional. Se analizan los datos correspondientes a los primeros 52 días de afectación de la enfermedad en el país para estimar los modelos y aplicar el método de los mínimos cuadrados para modelos no lineales con respecto a los parámetros. Se utilizan el coeficiente de determinación ajustado, el criterio de información de Akaike y el error estándar de los residuos para medir la bondad del ajuste de los modelos. Se estudian las provincias del país que presentan una tasa de infectados por cien mil habitantes mayor que 14,71 y el país en su conjunto. Resultados: La bondad de ajuste de los modelos utilizados en las localidades estudiadas y en el país es alta, lo cual permite su confiabilidad para los pronósticos efectuados. Conclusiones: Las predicciones plantean que las cinco localidades analizadas presentan su pico de contagio en abril al igual que Cuba (AU)

Introduction: Cuba and all its provinces have been affected by COVID-19 disease. The government and the health system have taken measures to avoid contagion from person to person. To take these measures it is important to have estimates of the rate of infection. Objectives: To obtain predictions for the peak of infected cases and the total number for some Cuban provinces and the whole country. Material and Methods: Predictive study of population growth curves. Data from the first 52 days of the disease in the country are processed to estimate the models and to apply the method of least squares estimation of nonlinear parameters. The adjusted coefficient of determination, the Akaike information criterion and the standard error of the residuals are used to measure the goodness of fit of the models. The provinces that present a rate of infection per 100,000 inhabitants greater than 14,71 and the country as a whole are studied. Results: The goodness of fit of the models used in the provinces studied and the country is high, which allows them to be reliable for predictions. Conclusions: The predictions suggest that the five provinces analyzed and Cuba show their peak of contagion in April (AU)

Life-history traits and the fate of translocated populations.

Attempts to identify predictors and mechanisms of invasion success have been weakened by poor data quality, mostly because monitoring does not begin immediately after introduction events. To overcome this issue, we used data from conservation translocations of threatened bird species. We analyzed information on >1200 translocation events of >150 bird species to investigate how life-history traits affect population establishment measured based on rates of survival and reproduction. Species position along the slow-fast life-history continuum was a key predictor of translocation success. Species with fast-paced life histories were less likely to survive (over both short- and mid-term) and more likely to breed successfully than species with slow life histories. The temporal partitioning of reproductive effort (number of clutches per year) also affected the probability of successful reproduction. Our results illustrate how conservation-motivated reintroduction programs can provide proxies for the initial stages of the invasion process, enabling empirical tests of predictions from life-history theory and informing management.

Atributos de las Historias de Vida y el Destino de las Poblaciones Reubicadas Resumen Los intentos por identificar los pronosticadores y los mecanismos del éxito de invasión han sido debilitados por la poca calidad de los datos, principalmente porque el monitoreo no inicia inmediatamente después de los eventos de introducción. Para superar este tema, usamos datos a partir de las reubicaciones por conservación de especies amenazadas de aves. Analizamos la información de más de 1,200 eventos de reubicación para más de 150 especies de aves y así investigar cómo los atributos de las historias de vida afectan el establecimiento de la población medido con base en tasas de supervivencia y reproducción. La posición de las especies a lo largo del continuo de historias de vida lenta-rápida fue un pronosticador importante para el éxito de la reubicación. Las especies con historias de vida rápidas tuvieron una menor posibilidad de sobrevivir (tanto a corto como a mediano plazo) y una mayor probabilidad de reproducirse exitosamente que las especies con historias de vida lentas. La división temporal del esfuerzo reproductivo (número de puestas por año) también afectó la probabilidad del éxito de la reproducción. Nuestros resultados ilustran cómo los programas de reintroducción motivados por la conservación pueden proporcionar sustitutos para los estadios iniciales del proceso de invasión, permitiendo pruebas empíricas a partir de la teoría de la historia de vida e informando a los administradores.

Predicting reintroduction outcomes for highly vulnerable species that do not currently coexist with their key threats.

Predicting reintroduction outcomes before populations are released is inherently challenging. It becomes even more difficult when the species being considered for reintroduction no longer coexists with the key threats limiting its distribution. However, data from other species facing the same threats can be used to make predictions under these circumstances. We used an integrated Bayesian modeling approach to predict growth of a reintroduced population at a range of predator densities when no data are available for the species in the presence of that predator. North Island Saddlebacks (Philesturnus rufusater) were extirpated from mainland New Zealand by exotic mammalian predators, particularly ship rats (black rats [Rattus rattus]) but are now being considered for reintroduction to sites with intensive predator control. We initially modeled data from previous saddleback reintroductions to predator-free sites to predict population growth at a new predator-free site while accounting for random variation in vital rates among sites. We then predicted population growth at different rat-tracking rates (an index of rat density) by incorporating a previously modeled relationship between rat-tracking and vital rates of another predator-sensitive species, the North Island Robin (Petroica longipes), and accounted for greater vulnerability of saddlebacks to rat predation based on information on historical declines of both species. The results allowed population growth to be predicted as a function of management effort while accounting for uncertainty, which means formal decision analysis could be used to decide whether to proceed with a reintroduction. Similar approaches could be applied to other situations where data on the species of interest are limited and provide an alternative to decision making based solely on expert judgment.

Influencia de la proporción sexual y del ambiente en la tasa de crecimiento poblacional de Callinectes bellicosus (Decapoda: Portunidae) del Golfo de California / Sex ratio and environmental influence on population growth rate of Callinectes bellicosus (Decapoda: Portunidae) in the Gulf of California

ResumenPara la jaiba café (Callinectes bellicosus) capturada en Sonora, México dentro del Golfo de California desde 1986, durante 20 años se ha observado una tendencia decreciente en la biomasa. Se estimaron las tasas de crecimiento poblacional (r) y proporción de sexos de C. bellicosus además de tres parámetros que describen su hábitat: temperatura del mar, extensión de humedales y tamaño del hábitat en cuatro zonas a lo largo de la costa de Sonora. La proporción de sexos se estimó de 25 556 jaibas muestreadas de las capturas comerciales en los años 19982002 y 2012; la temperatura media en el período de desove (mayo-agosto) se generó a partir de sensores remotos en los mismos años; la cobertura de humedales se obtuvo de reportes publicados; y el tamaño del hábitat se estimó como la superficie de pesca. Para cada zona se estimó r mediante un método desarrollado para situaciones de escasa información utilizando las capturas comerciales (t) de 1986 a 2013. Con los datos de las cuatro zonas se desarrollaron modelos de regresión lineal simple y múltiple para evaluar las sensibilidades teóricas de r a variaciones en la proporción de sexos y en los parámetros ambientales. Los machos dominaron (68.8 %) sobre las hembras en el período de estudio en las cuatro zonas; un análisis de conglomerados identificó dos grupos de acuerdo a la proporción de sexos: un grupo norteño con las zonas 1 y 2, y otro sureño con las zonas 3 y 4. Los valores de r fueron diferentes en las cuatro zonas (P<0.001) igual que la proporción de sexos (P=0.037); no se encontraron diferencias en la temperatura entre los años considerados en el estudio (P>0.995). Tanto los datos estimados como los análisis de sensibilidad sugieren que r dependen directa y positivamente de la proporción de hembras de jaiba y el tamaño de los humedales. Por lo anterior planteamos la hipótesis de que la pesca excesiva de hembras es la causa del descenso de la biomasa de jaiba café en Sonora, y concluimos que es conveniente implementar refugios pesqueros dentro de humedales costeros para proteger las hembras en el período de desove.

Abstract:The brown swimming crab (Callinectesbellicosus) is an economically important species in the Gulf of California, and its fishing activity, held in Sonora from 1986, has been affected by a 20-year declining trend in its biomass. With the aim to understand the possible reasons of this species population changes along time, we estimated population growth rate (r) and sex ratio of C. bellicosus, and combined them with three parameters describing its habitat: sea temperature, wetland extension and habitat size in four areas along the coast of Sonora. For this, monthly mean sex ratio was estimated from crabs samples obtained from commercial catches during 1998-2002 and 2012; mean sea surface temperature for the spawning period (May-August) were derived from remote sensors for the same years; while wetland coverages were obtained from published reports, and habitat size was estimated as the fishing surface. For each area, r was estimated using a method developed for limited data situations using commercial landings (t) from 1986-2013. With data from the four areas, simple and multiple linear regression models were developed to ascertain theoretical sensitivities of r to variations in sex ratio and environmental parameters. A total of 24 556 crabs were sampled; males dominated (68.8 %) over females during the study period and in all areas; a cluster analysis identified two groups according to sex ratio: a Northern group with zones 1 and 2, and a Southern group with zones 3 and 4. r values were different in all zones (P<0.001) as was sex ratio (P=0.037); no differences in temperature were identified within the study years (P>0.995). Both the estimated data and sensitivity analyses suggest the existence of a direct and positive dependence of r on the proportion of female crabs and wetland size. We hypothesize that excess fishing of females caused the declining biomass trend of the brown swimming crab in Sonora, and concluded on the convenience of implementing harvest refugia inside coastal wetlands to protect females during the spawning season. Rev. Biol. Trop. 64 (3): 1259-1271. Epub 2016 September 01.

The role of life histories and trophic interactions in population recovery.

Factors affecting population recovery from depletion are at the focus of wildlife management. Particularly, it has been debated how life-history characteristics might affect population recovery ability and productivity. Many exploited fish stocks have shown temporal changes towards earlier maturation and reduced adult body size, potentially owing to evolutionary responses to fishing. Whereas such life-history changes have been widely documented, their potential role on stock's ability to recover from exploitation often remains ignored by traditional fisheries management. We used a marine ecosystem model parameterized for Southeastern Australian ecosystem to explore how changes towards "faster" life histories might affect population per capita growth rate r. We show that for most species changes towards earlier maturation during fishing have a negative effect (3-40% decrease) on r during the recovery phase. Faster juvenile growth and earlier maturation were beneficial early in life, but smaller adult body sizes reduced the lifetime reproductive output and increased adult natural mortality. However, both at intra- and inter-specific level natural mortality and trophic position of the species were as important in determining r as species longevity and age of maturation, suggesting that r cannot be predicted from life-history traits alone. Our study highlights that factors affecting population recovery ability and productivity should be explored in a multi-species context, where both age-specific fecundity and survival schedules are addressed simultaneously. It also suggests that contemporary life-history changes in harvested species are unlikely to increase their resilience and recovery ability.

As migrações nas cidades médias de Minas Gerais e seus impactos no crescimento e na composição por sexo e idade da população no período 1980-2010 / Migration in the intermediate cities of Minas Gerais and its effects on population growth and sex and age composition in the period 1980-2010 / Las migraciones en las ciudades intermedias de Minas Gerais y sus impactos en el crecimiento y la composición por sexo y edad de la población en el período 1980-2010

O principal objetivo deste artigo é investigar as migrações nas cidades médias de Minas Gerais e os seus efeitos no crescimento e na composição por sexo e idade da população, no período 1980-2010. Para isso, foram utilizados os dados dos Censos Demográficos de 1980, 1991, 2000 e 2010 e os dados referentes ao quesito de migrante "data fixa" dos três últimos censos (desagregados por sexo e idade). Os resultados revelaram um quadro heterogêneo no que diz respeito aos impactos das migrações no volume e na composição das populações estudadas. Apesar de a maioria das cidades médias de Minas Gerais ter apresentado saldos migratórios positivos e relativamente altos em todos os períodos analisados, algumas exceções marcantes foram observadas na porção leste do Estado. Enquanto os efeitos das migrações na composição por sexo mostraram-se pouco significativos, os efeitos na estrutura etária foram substanciais, indicando uma forte tendência de os ganhos populacionais decorrentes da migração atuarem no sentido de reduzir o ritmo de envelhecimento populacional, em função da seletividade etária dos migrantes

The main objective of this paper is to investigate migration in the intermediate cities of Minas Gerais state in Brazil and its effects on growth and composition by age and sex of the population in the period 1980-2010. The data used came from the Demographic Censuses of 1980, 1991, 2000 and 2010 and from the question related to a previous place of residence at a fixed date over the last three censuses (disaggregated by sex and age). The results revealed a mixed picture regarding the impacts of migration on the volume and composition of the studied populations. Although most of the intermediate cities of Minas Gerais have shown positive and relatively high net migration in all analyzed periods, some striking exceptions were observed in the eastern portion of the state. While the effects of migration on the gender composition proved to be insignificant, effects on age structure were substantial, indicating a strong tendency for population gains from migration to slow population aging because of migrant age selectivity

El objetivo principal de este artículo es investigar las migraciones en las ciudades intermedias de Minas Gerais y sus efectos sobre el crecimiento y la composición por edad y sexo de la población en el período 1980-2010. Para ello se utilizaron datos de los censos demográficos de 1980, 1991, 2000 y 2010 y los relativos a la cuestión de los migrantes "de fecha fija anterior" de los tres últimos censos, desagregados por sexo y edad. Los resultados revelaron un panorama heterogéneo respecto de los impactos de las migraciones sobre el volumen y la composición de las poblaciones estudiadas. Aunque la mayoría de las ciudades intermedias de Minas Gerais han registrado saldos migratorios positivos y relativamente altos en todos los períodos analizados, se observaron algunas excepciones notables en la región oriental del estado. Mientras los efectos de las migraciones en la composición por sexo resultaron ser poco significativos, aquellos que incidieron sobre la estructura etaria fueron sustanciales, indicando una fuerte tendencia a que las ganancias de población resultantes de la migración actúen reduciendo el ritmo de envejecimiento poblacional debido a la selectividad por edad de los migrantes

VARIACIÓN DEMOGRÁFICA TEMPORAL DE LA TORTUGA DE RÍO CHOCOANA, Rhinoclemmys nasuta (GEOEMYDIDAE), EN ISLA PALMA, BAHÍA MÁLAGA, PACÍFICO DEL VALLE DEL CAUCA / Temporal Variation in Demography of the Chocoan River Turtle, Rhinoclemmys nasuta (Geoemydidae), on Isla Palma, Malaga Bay, Pacific Coast of Valle del Cauca

Pocos estudios demográficos de larga duración han sido realizados en tortugas dulceacuícolas de Suramérica, pese a la necesidad de este tipo de investigación para esclarecer las variaciones naturales y fortalecer procesos de conservación en este grupo particular. En esta investigación se estudió la variación en la demografía de una población de la tortuga de río chocoana (Rhinoclemmys nasuta), a partir de información registrada en una localidad insular del Pacífico colombiano entre 2005 y 2012. En esta localidad se capturaron manualmente tortugas en cinco riachuelos con un área total de 0,4 ha. Se calculó el tamaño poblacional con el método Jolly-Seber en cuatro periodos (2005-06, 2007, 2011 y 2012), y se comparó la estructura poblacional. Se estimó la probabilidad de supervivencia y la probabilidad de captura para machos, hembras y juveniles utilizando el modelo Cormack-Jolly-Seber, y la tasa de crecimiento poblacional con el modelo POPAN. Se evidenciaron aumentos y disminuciones en el tamaño de la población. Se evidenció un aumento significativo del porcentaje de juveniles que hacen parte de la población durante el periodo de estudio. En todos los periodos las hembras dominaron la estructura de sexos de la población. Las variaciones temporales en el tamaño poblacional pueden deberse a cambios naturales en el hábitat o a efectos denso-dependientes. Sin embargo, también pueden corresponder a fluctuaciones normales en los parámetros poblacionales, por lo tanto monitoreos continuos donde se puedan correlacionar factores ambientales y físicos del hábitat podrían permitirnos elucidar a que se deben estas variaciones.

Few long-term demographic studies have been conducted in freshwater turtles of South America despite the need for this type of inquiry to investigate natural variation and strengthen conservation efforts for these species. In this study, we examined variation in demography of the Chocoan River Turtle (Rhinoclemmys nasuta) based on a population from an island locality in the Colombian Pacific region between 2005 and 2012. At this locality we captured turtles by hand in five streams with a total area of 0.4 ha. We calculated population size with the Jolly-Seber method and compared the population structure of four time periods (2005-06, 2007, 2011 and 2012). We calculated the probability of survival and capture probability for males, females and juveniles using the Cormack -Jolly-Seber model and we estimated the rate of population growth with the POPAN model. We found increases and decreases in population size, and a significant increase in the percentage of juveniles in 2011 and 2012. In all periods, females dominated the sex structure of the population. Temporal variation in population size may be due to natural changes in habitat or density-dependent effects. However, it may correspond with normal fluctuations in population parameters, therefore continuous monitoring that can be correlated with environmental and physical factors of the habitat could elucidate the causes of the variation.

Efectos de la migración sobre el crecimiento poblacional a largo plazo de las provincias cubanas / Efeitos da migração sobre o crescimento populacional de longo prazo das províncias cubanas / Effects of migration on long-term population growth in the provinces of Cuba

Cuba es un país que, además de presentar niveles de fecundidad inferiores al nivel de reemplazo, ha registrado un significativo saldo migratorio negativo. Se observa también un intenso flujo migratorio interno cuyo patrón es muy diferente entre las provincias. Debido a la magnitud de estos flujos migratorios, la migración se presenta como un componente demográfico importante en la dinámica poblacional cubana. De esta forma, el objetivo de este trabajo es estimar el efecto de la migración interna e internacional sobre el potencial de crecimiento a largo plazo de Cuba y de sus provincias. Para esto, calculamos medidas de reproducción y de crecimiento poblacional a partir de los métodos demográficos convencionales y de la metodología propuesta por Preston y Wang (2007), que se basa en los métodos de variable r. Considerando el patrón demográfico corriente, en la mayoría de los territorios de Cuba se observa una reducción substantiva en la capacidad de reposición de las generaciones y en tamaño futuro de la población cuando se consideran los efectos de la migración.

Cuba é um país que, além de apresentar níveis de fecundidade inferiores ao nível de reposição, tem registrado um saldo migratório líquido negativo significativo. Observa-se também um intenso fluxo migratório interno, cujo padrão é bastante diferente nas diversas províncias do país. Devido à magnitude destes fluxos migratórios, a migração apresenta-se como um componente demográfico importante na dinâmica populacional cubana. Assim, o objetivo deste trabalho é estimar o efeito das migrações interna e internacional sobre o potencial de crescimento de longo prazo de Cuba e de suas províncias. Para tanto, foram calculadas medidas de reprodução e de crescimento populacional a partir dos métodos demográficos convencionais e da metodologia proposta por Preston e Wang (2007), que se baseia nos métodos da variável-r. Levando em conta o padrão demográfico atual, observa-se, na maioria dos territórios de Cuba, uma redução substantiva na capacidade de reposição das gerações e no tamanho futuro da população quando se consideram os efeitos da migração.

Cuba has shown very low fertility levels, even below replacement level, in addition to significant negative net migration flows. In the country's interior there is intense population mobility, characterized by different migration patterns from one province to another. In this article the effects of both internal and international migration flows on long-term population growth in Cuba and in its provinces are discussed. We estimate reproduction and population growth measures using conventional demographic methods, together with the methodology developed by Preston and Wang (2007), based on variable-r methods. Given current demographic patterns in the majority of Cuban provinces, and when migration effects are accounted for, our analysis shows significant negative consequences for the future maintenance of the Cuban population.

Actual and potential use of population viability analyses in recovery of plant species listed under the US endangered species act.

Use of population viability analyses (PVAs) in endangered species recovery planning has been met with both support and criticism. Previous reviews promote use of PVA for setting scientifically based, measurable, and objective recovery criteria and recommend improvements to increase the framework's utility. However, others have questioned the value of PVA models for setting recovery criteria and assert that PVAs are more appropriate for understanding relative trade-offs between alternative management actions. We reviewed 258 final recovery plans for 642 plants listed under the U.S. Endangered Species Act to determine the number of plans that used or recommended PVA in recovery planning. We also reviewed 223 publications that describe plant PVAs to assess how these models were designed and whether those designs reflected previous recommendations for improvement of PVAs. Twenty-four percent of listed species had recovery plans that used or recommended PVA. In publications, the typical model was a matrix population model parameterized with ≤5 years of demographic data that did not consider stochasticity, genetics, density dependence, seed banks, vegetative reproduction, dormancy, threats, or management strategies. Population growth rates for different populations of the same species or for the same population at different points in time were often statistically different or varied by >10%. Therefore, PVAs parameterized with underlying vital rates that vary to this degree may not accurately predict recovery objectives across a species' entire distribution or over longer time scales. We assert that PVA, although an important tool as part of an adaptive-management program, can help to determine quantitative recovery criteria only if more long-term data sets that capture spatiotemporal variability in vital rates become available. Lacking this, there is a strong need for viable and comprehensive methods for determining quantitative, science-based recovery criteria for endangered species with minimal data availability. Uso Actual y Potencial del Análisis de Viabilidad Poblacional para la Recuperación de Especies de Plantas Enlistadas en el Acta de Especies En Peligro de E.U.A.

Insights for integrated conservation from attitudes of people toward protected areas near Hwange National Park, Zimbabwe.

Increase in human settlements at the edge of protected areas (PAs) is perceived as a major threat to conservation of biodiversity. Although it is crucial to integrate the interests of surrounding communities into PA management, key drivers of changes in local populations and the effects of conservation on local livelihoods and perceptions remain poorly understood. We assessed population changes from 1990 to 2010 in 9 villages located between 2 PAs with different management policies (access to natural resources or not). We conducted semi-directive interviews at the household level (n =217) to document reasons for settlement in the area and villager's attitudes toward the PAs. We examined drivers of these attitudes relative to household typology, feelings about conservation, and concerns for the future with mixed linear models. Population increased by 61% from 2000 to 2010, a period of political and economic crisis in Zimbabwe. Forty-seven percent of immigrants were attracted by the area; others had been resettled from other villages or were returning to family lands. Attitudes toward PAs were generally positive, but immigrants attracted by the area and who used resources within the PA with fewer restrictions expressed more negative attitudes toward PAs. Household location, losses due to wild animals, and restrictions on access to natural resources were the main drivers of this negative attitude. Profit-seeking migrants did not expect these constraints and were particularly concerned with local overpopulation and access to natural resources. To avoid socio-ecological traps near PAs (i.e., unforeseen reduced adaptive capacity) integrated conservation should address mismatches between management policy and local expectations. This requires accounting for endogenous processes, for example, local socio-ecological dynamics and values that shape the coexistence between humans and wildlife.

Chytridiomycosis and seasonal mortality of tropical stream-associated frogs 15 years after introduction of Batrachochytrium dendrobatidis.

Assessing the effects of diseases on wildlife populations can be difficult in the absence of observed mortalities, but it is crucial for threat assessment and conservation. We performed an intensive capture-mark-recapture study across seasons and years to investigate the effect of chytridiomycosis on demographics in 2 populations of the threatened common mist frog (Litoria rheocola) in the lowland wet tropics of Queensland, Australia. Infection prevalence was the best predictor for apparent survival probability in adult males and varied widely with season (0-65%). Infection prevalence was highest in winter months when monthly survival probabilities were low (approximately 70%). Populations at both sites exhibited very low annual survival probabilities (12-15%) but high recruitment (71-91%), which resulted in population growth rates that fluctuated seasonally. Our results suggest that even in the absence of observed mortalities and continued declines, and despite host-pathogen co-existence for multiple host generations over almost 2 decades, chytridiomycosis continues to have substantial seasonally fluctuating population-level effects on amphibian survival, which necessitates increased recruitment for population persistence. Similarly infected populations may thus be under continued threat from chytridiomycosis which may render them vulnerable to other threatening processes, particularly those affecting recruitment success.

Demography of zooplankton (Anuraeopsis fissa, Brachionus rubens and Moina macrocopa) fed Chlorella vulgaris and Scenedesmus acutus cultured on different media

Generally zooplankton growth is often limited by the quality of their algal diet. A cheaper common practice in aquaculture, is to culture algae with fertilizers; however, the demography of zooplankton when fed these algae has not yet been evaluated. We studied the population growth and life table demography of the rotifers Anuraeopsis fissa and Brachionus rubens, and the cladoceran Moina macrocopa. For this, the algae Scenedesmus acutus or Chlorella vulgaris were cultured on defined (Bold’s basal) medium or the commercial liquid fertilizer (Bayfolan). Experiments were conducted at one algal concentration 1.0x10(6)cells/mL of C. vulgaris or its equivalent dry weight of 0.5x10(6)cells/mL of S. acutus. The population dynamics were tested at 23±1ºC in 100mL transparent jars, each with 50mL of the test medium, with an initial density of 0.5indiv/mL, for a total of 48 test jars (3 zooplankton 2 algal species x 2 culture media x 4 replicates). For the life table experiments with M. macrocopa, we introduced 10 neonates (<24h old) into each test jar containing the specific algal type and concentration. For the rotifer experiments, we set 5mL tubes with one neonate each and 10 replicates for each algal species and culture medium. We found that the average rotifer life span was not influenced by the diet, but for M. macrocopa fed S. acutus cultured in Bold’s medium, the average lifespan was significantly lower than with the other diets. The gross and net reproductive rates of A. fissa (ranging from 18-36 offspring per female) were significantly higher for C. vulgaris cultured in Bold medium. Regardless of the culture medium, Chlorella resulted in significantly higher gross and net reproductive rates for B. rubens than S. acutus diets. The reproductive rates of M. macrocopa were significantly higher in all the tested diets except when fed with S. acutus in Bold medium. The population increase rate, derived from growth experiments of A. fissa and B. rubens, ranged from 0.1-0.25/d and were significantly higher on C. vulgaris cultured in liquid fertilizer as compared to the other diets. The growth rates of M. macrocopa ranged from 0.1 to 0.38/d, and were highest with diets of C. vulgaris cultured in Bold medium and S. acutus cultured in fertilizer. Thus, regardless of the culture medium used, the growth rates of the evaluated zooplankton species were higher with Chlorella than with Scenedesmus. The peak population density was highest (2 800ind/mL) for A. fissa fed Chlorella that was cultured on liquid fertilizers, while B. rubens and M. macrocopa had peak abundances of 480 and 12ind/mL, respectively under similar conditions.

Generalmente el crecimiento del zooplancton está a menudo limitado por la calidad de su dieta de algas. La demografía del zooplancton durante la alimentación con algas no ha sido estudiada, a pesar de que el cultivo de algas con fertilizantes es una práctica económica común en acuacultura. Se analizó la demografía de Anuraeopsis fissa y Brachionus rubens (rotíferos) y Moina macrocopa (cladóceros), alimentados con las algas verdes Scenedesmus acutus o Chlorella vulgaris cultivadas en medio Bold o fertilizante líquido comercial (Bayfolan, de Bayer). En los rotíferos no se observaron diferencias significativas en el promedio de vida, sin embargo, este parámetro en M. macrocopa con S. acutus cultivada en Medio Bold, fue significativamente menor que en otras dietas. Las tasas de reproducción bruta y neta de A. fissa fueron significativamente mayores con C. vulgaris cultivada en medio Bold, que con el fertilizante; estas tasas en B. rubens, independientemente del medio de cultivo, resultaron significativamente mayores con Chlorella que S. acutus. La tasa de reproducción de M. macrocopa fue significativamente mayor en todas, a excepción de S. acutus en Bold. En el crecimiento poblacional con A. fissa y B. rubens la tasa de crecimiento poblacional varió de 0.1 hasta 0.25/d, significativamente mayores en C. vulgaris cultivadas con fertilizante, en comparación con las otras dietas; en M. macrocopa la tasa de crecimiento varió desde 0.1 hasta 0.38/d, las más altas fueron: con C. vulgaris cultivadas en medio Bold y S. acutus cultivadas con fertilizante. Así, en todas las especies, la tasa de crecimiento fue más alta con Chlorella que con Scenedesmus.

Experimental culture of Cyclopina sp with differents microalgae’s species / Cultivo experimental de Cyclopina sp con diferentes especies de microalgas / Cultura experimental de Cyclopina sp com diferentes espécies de microalgas

Copepods are the main natural prey for most marine fish and other marine crustaceans and their nauplius, thus playing a fundamental role in aquatic food webs. There is a need to investigate the potential of copepods species found in Colombian coasts for the development of marine aquaculture. Objective: evaluate the performance of the marine copepod Cyclopina sp fed with different microalgae species. Methods: experimental cultures were conducted in 10 L aquariums with an initial density of 2 copepods/ mL, constant aeration and 24 h light. Treatments consisted of feeding the copepods with a combination of two microalgae species in a 70:30 ratio, at concentrations of 4x10(5) cells/mL, as follows: T1 = Tetraselmis suecica + Isochrysis galbana, T2 = I. galbana. + Nannochloropsis oculata, T3 = N. oculata. + T. suecica, T4 = Yeast (Saccharomyces cerevisiae). Temperature (ºC), salinity (%), dissolved oxygen (mg/L), pH, were registered daily, and the growth and population dynamics were evaluated every 48 hours for 15 days. Results: the greater density of total copepods (10± 3 copepods/ml) and number of nauplii (6 ± 2 nauplii/ mL), were registered on day 15 in T1, being significantly different (p<0.05) from any other treatments. Conclusions: the best growth and reproduction were attained in copepod populations fed with the combination of microalgae T. suecica + I. galbana (T1).

Los copépodos son la principal presa natural para la mayoría de larvas de peces y crustáceos marinos y sus nauplios como alimento vivo representan un papel fundamental en la sobrevivencia de las larvas. Objetivo: establecer el potencial de especies de copépodos presentes en las costas colombianas para el desarrollo de la piscicultura marina, siendo objetivo de esta investigación, evaluar el desempeño del copépodo marino Cyclopina sp alimentado con diferentes especies de microalgas. Métodos: cultivos experimentales se realizaron en acuarios con volumen útil de 10 litros, a densidad inicial de 2 copépodos/ ml, con aireación y luz constante. Combinaciones de microalgas (proporción 70:30) en concentración 4x10(5) cel/ml. Se usaron como tratamientos: T1 = Tetraselmis suecica + Isochrysis galbana, T2 = I. galbana + Nannochloropsis oculata, T3 = N. oculata + T. suecica, T4 = Levadura (Saccharomyces cerevisiae). Diariamente se registró la temperatura (ºC), salinidad (‰), oxígeno disuelto (mg/L), pH y se evaluaron cada 2 días el crecimiento y la composición poblacional durante el tiempo de cultivo. Resultados: la mayor densidad de copépodos totales (10 ± 3 copépodos/ml) y el mayor número de nauplios (6 ± 2 nauplios/ ml), se registraron el día 15 en T1, mostrando diferencias significativas (p<0.05) respecto a los demás tratamientos. Conclusión: los mejores crecimiento y composición poblacional, se registraron en las poblaciones alimentadas con la combinación de las microalgas T. suecica e I. galbana (T1).

Os copépodos são a principal presa natural para a maioria de larvas de peixes e crustáceos marinhos e seus náuplios como alimento vivo desempenhan um papel fundamental na sobrevivência das larvas. Objetivo: estabelecer o potencial de espécies de copépodos presentes nas costas colombianas para o desenvolvimento da piscicultura marinha, sendo o objetivo desta pesquisa avaliar o desempenho do copépodo marinho Cyclopina sp alimentado com diferentes espécies de microalgas. Métodos: culturas experimentais foram realizadas em aquarios com volume útil de 10 litros, densidade inicial de 2 copépodos/ ml, com aeração e luz constante. Combinações de microalgas (proporção 70:30) em concentração 4x10(5) cel/ml, foram usadas como tratamentos: T1 = Tetraselmis suecica + Isochrysis galbana, T2 = I. galbana + Nannochloropsis oculata, T3 = N. oculata + T. suecica, T4 = Levadura (Saccharomyces cerevisiae). Foi registrada diariamente a temperatura (°C), salinidade (‰), oxigênio dissolvido (mg/L) e pH. A cada dois días foram avaliados o crescimento e composição populacional durante o tempo de cultivo. Resultados: a maior densidade de copépodos totais (10 ± 3 copépodos/ml) e o maior número de náuplios (6 ± 2 náuplios/ ml), foram registrados no día 15 do T1, apresentando diferença estatística significativa (p<0.05) em comparação com os outros tratamentos. Conclusõe: o maior crescimento e composição populacional foi registrado na população alimentada com a combinação de microalgas T. suecica e I. galbana (T1).