S1 Table -

Summary of random-effect model selection for (a) hatching success, (b) hatchability, and (c) fledging success of Eastern bluebirds and Carolina chickadees at the species and species-region levels. No fixed terms were included. Though the model with nest location was not always the most parsimonious, we included this random variable in all our models for consistency across analyses. Models are presented with corresponding k (number of parameters), AIC (Akaike’s Information Criterion), ΔAIC (difference in AIC between given model and lowest AIC model), and wi (model weight) values. (DOCX)</p

Five-(black) and seven-year (grey) sliding window correlations of three nesting parameters.

Correlations for hatching success, hatchability, and fledging success were calculated between (a) Atlantic Coast and Central Hardwoods bluebirds, (b) Atlantic Coast and Central Hardwoods chickadees, (c) Atlantic Coast bluebirds and chickadees, and (d) Central Hardwoods bluebirds and chickadees. The central year of each window is displayed on the x axis; for example, the year 2000 for the five-year window represents the period 1998–2002. Significant periods of correlation are indicated by asterisk.</p

Nest locations per region [31].

Nesting data for Eastern bluebirds and Carolina chickadees were collected by NestWatch participants, 1998–2018. Each point represents the site of at least one nesting attempt. The Migratory Bird Joint Ventures region shapefile was provided by the U.S. Fish and Wildlife Service [32].</p

Fig 1 -

A fictitious scenario in which two species exhibit (a) positive synchronous fluctuations (r = 1.00), (b) negative synchronous fluctuations (r = -1.00), and (c) asynchronous fluctuations (r = 0.00) in a given demographic parameter.</p

Mean (± SE), relative variance (RV), coefficient of variation (CV), sample size (<i>n</i>), and the minimum and maximum number of nests per year (Range) for hatching success, hatchability, and fledging success of Eastern Bluebirds and Carolina Chickadees in the Atlantic Coast (AC) and Central Hardwoods (CH) regions, 1998–2018.

Means are averages of annual estimates obtained from the generalized mixed models (GLMM). Standard errors were calculated using these mean values. RV and CV measure variability in GLMM-produced annual estimates of our nesting parameters.</p