title: Abundance models improve spatial and temporal prioritization of conservation resources.
abstract: Conservation prioritization requires knowledge about organism distribution and density. This information is often inferred from models that estimate the probability of species occurrence rather than from models that estimate species abundance, because abundance data are harder to obtain and model. However, occurrence and abundance may not display similar patterns and therefore development of robust, scalable, abundance models is critical to ensuring that scarce conservation resources are applied where they can have the greatest benefits. Motivated by a dynamic land conservation program, we develop and assess a general method for modeling relative abundance using citizen science monitoring data. Weekly estimates of relative abundance and occurrence were compared for prioritizing times and locations of conservation actions for migratory waterbird species in California, USA. We found that abundance estimates consistently provided better rankings of observed counts than occurrence estimates. Additionally, the relationship between abundance and occurrence was nonlinear and varied by species and season. Across species, locations prioritized by occurrence models had only 10-58% overlap with locations prioritized by abundance models, highlighting that occurrence models will not typically identify the locations of highest abundance that are vital for conservation of populations.
authors.forename: Alison
authors.initials: A
authors.lastname: Johnston
authors.forename: Daniel
authors.initials: D
authors.lastname: Fink
authors.forename: Mark D
authors.initials: MD
authors.lastname: Reynolds
authors.forename: Wesley M
authors.initials: WM
authors.lastname: Hochachka
authors.forename: Brian L
authors.initials: BL
authors.lastname: Sullivan
authors.forename: Nicholas E
authors.initials: NE
authors.lastname: Bruns
authors.forename: Eric
authors.initials: E
authors.lastname: Hallstein
authors.forename: Matt S
authors.initials: MS
authors.lastname: Merrifield
authors.forename: Sandi
authors.initials: S
authors.lastname: Matsumoto
authors.forename: Steve
authors.initials: S
authors.lastname: Kelling
mesh_terms: D063147:Animal Distribution; D000818:Animals; D046090:Anseriformes / Q000502:physiology; D002140:California; D003247:Conservation of Natural Resources / Q000379:methods*; D017753:Ecosystem; D008954:Models, Biological; D000067936:Natural Resources; D011156:Population Density; D012621:Seasons; D013045:Species Specificity; D013997:Time Factors