Integrating broad‐scale data to assess demographic and climatic contributions to population change in a declining songbird

Abstract

Climate variation and trends affect species distribution and abundance across large spatial extents. However, most studies that predict species response to climate are implemented at small spatial scales or are based on occurrence‐environment relationships that lack mechanistic detail. Here, we develop an integrated population model (IPM) for multi‐site count and capture‐recapture data for a declining migratory songbird, Wilson's warbler (Cardellina pusilla), in three genetically distinct breeding populations in western North America. We include climate covariates of vital rates, including spring temperatures on the breeding grounds, drought on the wintering range in northwest Mexico, and wind conditions during spring migration. Spring temperatures were positively related to productivity in Sierra Nevada and Pacific Northwest genetic groups, and annual changes in productivity were important predictors of changes in growth rate in these populations. Drought condition on the wintering grounds was a strong predictor of adult survival for coastal California and Sierra Nevada populations; however, adult survival played a relatively minor role in explaining annual variation in population change. A latent parameter representing a mixture of first‐year survival and immigration was the largest contributor to variation in population change; however, this parameter was estimated imprecisely, and its importance likely reflects, in part, differences in spatio‐temporal distribution of samples between count and capture‐recapture data sets. Our modeling approach represents a novel and flexible framework for linking broad‐scale multi‐site monitoring data sets. Our results highlight both the potential of the approach for extension to additional species and systems, as well as needs for additional data and/or model development.

Interrelated impacts of climate and land‐use change on a widespread waterbird

“…To determine the vulnerability of populations to changing environmental conditions, it is critical to link vital rates to ecological covariates that will be impacted by global change (Saracco & Rubenstein, 2019). Our IPM-BPVA revealed that (a) climate affects loon population dynamics via both reproduction and adult survival, (b) interactions between different climate variables result in complex patterns of population dynamics such that the effects of climatic conditions may take multiple years to become apparent in a long-lived, high-trophic level species (Crespin et al, 2006;Salvidio et al, 2016) and ( Northrup et al, 2019;Sohl, 2014).…”

Apparent breeding success drives long‐term population dynamics of a migratory swan

“…The importance of apparent breeding success as indicated by the LTRE (Fig. 2) must be treated with some care, as it is known that latent variables often seem to explain large proportions of the growth rates (Ahrestani et al 2017, Saracco and Rubenstein 2020), potentially because they may absorb systematic bias associated with the different datasets (Tavecchia et al 2009, Taylor et al 2018).…”

North American Breeding Bird Survey underestimates regional bird richness compared to Breeding Bird Atlases

“…Many of these studies were explicitly designed to aid in biodiversity conservation (Hudson et al, 2017; Rosenberg et al, 2017). For the same reason, BBS data have often been used as a yardstick for evaluating the performance of new modeling tools in ecology (Link et al, 2020; Saracco & Rubenstein, 2020; Valle et al, 2018) and conservation (Cam, Nichols, Sauer, et al, 2002; Polasky et al, 2001), as well as for testing general concepts and theories of community ecology such as the scaling of population variability (Keitt & Stanley, 1998), the species pool hypothesis (Cam et al, 2000), biotic homogenization (Martin et al, 2017; Sorte & McKinney, 2007), abundance–occupancy relationships (Zuckerberg, Porter, et al, 2009), area‐heterogeneity trade‐off (Chocron et al, 2015), the insurance hypothesis (Valone & Barber, 2008), diversity–stability relationships (Catano et al, 2020), and many more (Bertuzzo et al, 2011; Hansen et al, 2011; Maurer et al, 2013; McGill, 2003; Mikkelson et al, 2011; Mimet et al, 2019; Osorio‐Olvera et al, 2020).…”