DOI: 10.5061/dryad.hv631
title: Data from: Spatial dynamics of habitat use informs reintroduction efforts in the presence of an invasive predator

description: 1. Islands experience major impacts from introduced species, especially
 nocturnal predators. The Brown Treesnake (Boiga irregularis) extirpated
 almost the entire native avifauna on Guam shortly after introduction.
 Reintroductions from neighboring islands can restore bird communities but
 will take place in heavily managed units where snake populations can be
 controlled. Yet reintroductions often proceed without relevant biological
 information such as nocturnal habitat and space use when nocturnal
 predators are present. To guide efforts, we studied diurnal and nocturnal
 habitat and space use by the avian frugivore community on the nearby
 island of Saipan where the snake is absent. 2. Using radio telemetry and a
 Bayesian framework, we first compared data typically accessible to
 resource managers (diurnal home range [DHR] and habitat selection) and
 which often forms the basis of reintroduction plans. We contrast this with
 data on nocturnal habitat use that is often not available but relevant
 when nocturnal predation threat is high. 3. DHR size varied within and
 among species with Micronesian Starlings (Aplonis opaca) having DHRs at
 least 45 ha larger than other species. For all species, night roost
 locations were generally spatially clustered within a DHR and covered a
 smaller spatial extent. Two species had higher probabilities of roosting
 outside DHR boundaries but, when outside, roosts were often within 200 m
 of the DHR boundary. All species selected forested habitats during day and
 night, with some species choosing native forest over non-native habitat.
 4. Synthesis and applications If individuals roosted randomly throughout
 DHR’s, landscape-level suppression of B. irregularis might be the only
 viable option for reintroductions of some species. However, individuals of
 all species showed clustered roosting and high site fidelity. If site
 fidelity is common, then individuals that roost within fenced areas where
 snake populations are severely reduced or eliminated will experience high
 survivorship even if DHRs extend into surrounding unprotected matrix.
 There was large overlap in habitat selection during day and night
 indicating managed areas should be composed of native forest with
 non-native forests of secondary importance. In systems with nocturnal
 predators, understanding variability in diurnal and nocturnal habitat use
 could lead to better informed decisions.
description: Nocturnal location data
 for birds on SaipanEach row represents a
 single location for a bird. X and Y columns correspond to the estimated X
 and Y location, in UTMs, for a given bird on Saipan. Individual Bird IDs
 are in the Bird_ID column and a species identifier is given in the Sp
 column.nocturnal_locations.csvEstimated diurnal location data for birds on SaipanEach row represents a single location for a bird. X and Y columns correspond to the estimated X and Y location, in UTMs, for a given bird on Saipan. Individual Bird IDs are in the Bird_ID column and a species identifier is given in the Sp column. Rows with NA mean that the bird was not located during that movement intervaldiurnal_locations.csv