Apparent survival of tropical birds in a wet, premontane forest in Costa Rica

Abstract

Despite the importance of tropical birds in the development of life history theory, we lack information about demographic rates and drivers of population dynamics for most species. We used a 7‐year (2007–2013) capture‐mark‐recapture dataset from an exceptionally wet premontane forest at mid‐elevation in Costa Rica to estimate apparent survival for seven species of tropical passerines. For four of these species, we provide the first published demographic parameters. Recapture probabilities ranged from 0.21 to 0.53, and annual estimates of apparent survival varied from 0.23 to 1.00. We also assessed the consequences of inter‐annual variation in rainfall on demographic rates. Our results are consistent with inter‐annual rainfall increasing estimates of apparent survival for two species and decreasing estimates for three species. For the three species where we could compare our estimates of apparent survival to estimates from drier regions, our estimates were not consistently higher or lower than those published previously. The temporal and spatial variability in demographic rates we document within and among species highlights the difficulties of generalizing life history characteristics across broad biogeographic gradients. Most importantly, this work emphasizes the context‐specific role of precipitation in shaping tropical avian demographic rates and underscores the need for mechanistic studies of environmental drivers of tropical life histories.

A meta‐analysis of global avian survival across species and latitude

“…2017; Shogren et al . 2019) in mm, and minimum winter temperature (Robinson et al . 2007; Salewski et al .…”

“…Our modelling approach allowed us to estimate a unique latitude and longitude for the centroid of each species' realised breeding range rather than simply selecting an unweighted point in the study area itself. As latitude is often used as a surrogate for variation in climatic conditions between the north and south poles, we evaluated the predictive power of three key extrinsic factors that characterise the environment of a species and are hypothesised to influence avian survival: annual precipitation (Rockwell et al 2017;Shogren et al 2019) in mm, and minimum winter temperature (Robinson et al 2007;Salewski et al 2013) and temperature seasonality (Ricklefs 1980;Lloyd et al 2014) measured in°C. We also tested whether species' intrinsic traits explained global patterns in avian survival rates by collecting data on body mass, clutch size, and species' migratory habit, which we obtained from information contained in the paper, published reference databases (i.e., Jetz et al 2008 for clutch size; Wilman et al 2014 for body mass; Barc ßante et al 2017 for migration), or the Handbook of Birds of the World Alive (del Hoyo et al 2019).…”

Hygric Niches for Tropical Endotherms

“…Direct, but sublethal, consequences of storms include elevated thermoregulatory costs [52] affecting condition. Compromised condition may cumulatively influence apparent survival [53] by elevating susceptibility to disease, predation, or propensity to emigrate [54]. Additionally, sublethal effects of wet years can negatively affect subsequent reproductive success [55].…”

Building a mechanistic understanding of climate-driven elevational shifts in birds

“…Similarly, in the western United States, droughts were found to reduce productivity and adult survival across 51 desert species [115]. However, responses to changes in rainfall can vary greatly within bird communities as some species respond positively to increased rainfall, and others negatively [116]. Even within a single species, rainfall regimes have contrasting effects on breeding phenology in different parts of their range [117], demonstrating the difficulty in predicting responses to changing patterns of precipitation [82].…”