Anthropogenic Renourishment Feedback on Shorebirds: a Multispecies Bayesian Perspective

22 In this paper the realized niche of the Snowy Plover (Charadrius alexandrinus), a 23 primarily resident Florida shorebird, is described as a function of the scenopoetic and 24 bionomic variables at the nest-, landscape-, and regional-scale. We identified some pos25 sible geomorphological controls that influence nest-site selection and survival using data 26 collected along the Florida Gulf coast. In particular we focused on the effects of beach 27 replenishment interventions on the Snowy Plover (SP), and on the migratory Piping 28 Plover (PP) (Charadrius melodus) and Red Knot (RK) (Calidris canutus). Addition29 ally we investigated the potential differences between the SP breeding and wintering 30 distributions using only regional-scale physiognomic variables and the recorded occur31 rences. To quantify the relationship between past renourishment projects and shorebird 32 species we used a Monte Carlo procedure to sample from the posterior distribution of the 33 binomial probabilities that a region is not a nesting or a wintering ground conditional 34 on the occurrence of a beach replenishment intervention in the same and the previous 35 year. The results indicate that it was 2.3, 3.1, and 0.8 times more likely that a region 36 was not a wintering ground following a year with a renourishment intervention for the 37 SP, PP and RK respectively. For the SP it was 2.5. times more likely that a region 38 was not a breeding ground after a renourishment event. Through a maximum entropy 39 principle model we observed small differences in the habitat use of the SP during the 40 breeding and the wintering season. However the habitats where RK was observed ap41 peared quite different. While ecological niche models at the macro-scale are useful for 42 determining habitat suitability ranges, the characterization of the species’ local niche 43 is fundamentally important for adopting concrete multispecies management scenarios. 44 Maintaining and creating optimal suitable habitats for SP characterized by sparse low 45 vegetation in the foredunes areas, and uneven/low-slope beach surfaces, is the proposed 46 conservation scenario to convert anthropic beach restorations and SP populations into 47 a positive feedback without impacting other threatened shorebird species. 48