Nest survival modelling using a multi‐species approach in forests managed for timber and biofuel feedstock

Abstract

Switchgrass (Panicum virgatum) intercropping is a novel forest management practice for biomass production intended to generate cellulosic feedstocks within intensively managed loblolly pine‐dominated landscapes. These pine plantations are important for early‐successional bird species, as short rotation times continually maintain early‐successional habitat. We tested the efficacy of using community models compared to individual surrogate species models in understanding influences on nest survival. We analysed nest data to test for differences in habitat use for 14 bird species in plots managed for switchgrass intercropping and controls within loblolly pine (Pinus taeda) plantations in Mississippi, USA. We adapted hierarchical models using hyper‐parameters to incorporate information from both common and rare species to understand community‐level nest survival. This approach incorporates rare species that are often discarded due to low sample sizes, but can inform community‐level demographic parameter estimates. We illustrate use of this approach in generating both species‐level and community‐wide estimates of daily survival rates for songbird nests. We were able to include rare species with low sample size (minimum n = 5) to inform a hyper‐prior, allowing us to estimate effects of covariates on daily survival at the community level, then compare this with a single‐species approach using surrogate species. Using single‐species models, we were unable to generate estimates below a sample size of 21 nests per species. Community model species‐level survival and parameter estimates were similar to those generated by five single‐species models, with improved precision in community model parameters. Covariates of nest placement indicated that switchgrass at the nest site (<4 m) reduced daily nest survival, although intercropping at the forest stand level increased daily nest survival. Synthesis and applications. Community models represent a viable method for estimating community nest survival rates and effects of covariates while incorporating limited data for rarely detected species. Intercropping switchgrass in loblolly pine plantations slightly increased daily nest survival at the research plot scale (0.1 km2), although at a local scale (50 m2) switchgrass negatively influenced nest survival. A likely explanation is intercropping shifted community composition, favouring species with greater disturbance tolerance.

Behavioral strategies during incubation influence nest and female survival of Wild Turkeys

“…We compared posterior estimates of effects of each covariate on nest and female survival using pd values. We interpreted values close to 0.5 to suggest no biological effect of covariates, but values ≥0.9 as biologically significant (Loman et al., 2018; Ruiz‐Gutiérrez et al., 2010).…”

Methods for collecting data about the breeding biology of Neotropical birds

“…Finally, Loman et al. (2018) recently used Bayesian theory to estimate multi‐species nest survival with implications for conservation management of avian communities. The advantage of this method is that it allows the use of data from common as well as rare species that are usually discarded due to small sample sizes.…”

“…Finalmente, Loman et al (2018) utiliz o recientemente an alisis bayesianos para estimar la supervivencia de nidos de m ultiples especies con implicaciones para el manejo de la conservaci on de las comunidades de aves. La ventaja de este m etodo es que permite el uso de datos de especies comunes y raras que generalmente se descartan debido a tamaños de muestra pequeños.…”

Systematic Review of Bird Response to Privately-Owned, Managed Pine Stands in the Southeastern U.S.

“…Early studies in managed pine landscapes provided anecdotal evidence that birds were nesting successfully, and that there was variation in breeding activity and nest success [65]. We now know that nesting rates vary with intensity of stand establishment practices and intermediate forest management strategies [44,65,126,127]. Evidence suggests that managed pine stands may serve as both population sources and sinks depending on several factors, including stand age, distance to forest edge, and stand adjacency [44,128,129].…”

“…Stand-scale vegetative structure may play a larger role in nest success than features of the surrounding landscape [44,61]. However, studies assessing reproductive success are few and far between, and some address very specific management questions (e.g., [126,127,129,132]). Studies of annual survival are even rarer and require substantial investment in tracking marked individuals to be successful [133].…”