DOI: 10.5061/dryad.44j0zpcrj
title: Data from: Environmental conditions and individual characteristics influence movement patterns of juvenile Passerculus sandwichensis (Savannah sparrow) throughout the post-fledging period

description: Movements in the post-fledging period, an important first stage of natal
 dispersal that occurs after juveniles fledge from the nest but before they
 depart for fall migration, have important implications for survival.
 However, relatively little is known about movements during this vulnerable
 period. Here, we used daily radio telemetry data from 137 juvenile
 Passerculus sandwichensis (Savannah sparrows) between 2022-2024 and
 hierarchical generalized additive models to examine the relationship
 between movement and age across a 90-day period. We evaluated how
 movement—distance from the nest and between consecutive daily
 locations—was influenced by age post-fledging, sex, brood number, year,
 age at fledging, local nest density, nestling mass, and weather variables.
 Both the distance of fledglings from their natal nest and distance moved
 between days increased with age post-fledging, most steeply when
 fledglings became independent, then remained steady for the remainder of
 the post-fledging period. Movement varied among individuals: some
 fledglings remained near the nest for extended periods and others traveled
 long distances soon after fledging. Offspring from second broods traveled
 greater distances than those from first broods. Nest density also
 influenced movement, with fledglings from high density areas traveling
 farther from their nests but, on average, less far between days. Movement
 patterns were also influenced by year and sex, and weakly influenced by
 mass and daily precipitation. Our results demonstrate how movement
 patterns can change between the early post-fledging period and the
 relatively understudied late post-fledging period.
description: # Data from: Environmental conditions and individual characteristics
 influence movement patterns of juvenile Passerculus sandwichensis
 (Savannah sparrow) throughout the post-fledging period Dataset DOI:
 [10.5061/dryad.44j0zpcrj](10.5061/dryad.44j0zpcrj) ## Description of the
 data and file structure We used radio telemetry data from 137 juvenile
 Savannah sparrows in a population breeding on Kent island, NB, Canada,
 between 2022 and 2024 to evaluate the ecological and individual factors
 influencing movement behavior: the distance individuals travelled from
 their natal nests and the distances travelled between consecutive daily
 locations. Juveniles were located once per day using radio telemetry and
 their fate (alive, dead, or unknown) noted. All individuals breeding
 within the study area and all nestlings that received radio transmitters
 were marked with a unique combination of color bands and a USFWS aluminum
 band. Nestlings without radio transmitters were marked with one color band
 and one aluminum band. Each year, we recorded the identities of all adults
 breeding on the study site. We found and monitored all nest attempts every
 year to produce reproductive data including fledge date and brood number
 (whether the nest is the first brood attempted by a pair in that year, or
 a second brood produced after the first brood fledged) and to band and
 measure nestlings. ### Files and variables All date variables are
 formatted as mm/dd/yy. #### File: nests\_2022\_to\_2024.csv
 **Description:** This dataset includes records for all nests on the study
 site between 2022 and 2024, including nests in which no young received
 radio transmitters. NAs in female ID and male ID represent cases in which
 the male or female parent of the nest was unknown or was not banded. NAs
 in date variables represent cases in which the date is not applicable
 (e.g. a nest that fledged young does not have a fail date). #####
 Variables * nest_key: An identification key for the nest record, which
 uniquely identifies each nest. Includes a year code for each nest
 ("122" = 2022, "123" = 2023, "124" = 2024).
 * nest_id: The nest key without the year code; not uniquely identifying
 (e.g. the nest ID "M26A" may be present in multiple years and
 does not represent the same nest in each year). * year: The year in which
 the nest occurred. * eggs_laid: The number of eggs laid in the nest
 (clutch size). * female_id: The band number of the female parent of the
 nest, which uniquely identifies individual females. * male_id: The band
 number of the male parent of the nest, which uniquely identifies
 individual males. * found_date: The date the nest was found. * hatch_date:
 The date the first egg in the nest hatched. * eggs_hatched: The number of
 eggs in the nest that hatched. * fledglings: The number of young that
 fledged from the nest. * fledge_date: The date on which the first young
 fledged from the nest. * fate: The fate of the nest; AE = abandoned with
 eggs, AN = abandoned with nestlings, FL = fledged, PE = predated with
 eggs. * x_coord: The x coordinate of the nest, recorded as an easting in
 UTM Zone 19 N. * y_coord: The y coordinate of the nest, recorded as a
 northing in UTM Zone 19 N. * fail_date: The date the nest failed, if
 applicable. * study_site: The location of the nest on Kent Island. Nests
 in the main study area are represented by "N" (North Field) or
 "S" (South Field). Nests outside the main study area are
 represented by "EN" and "WB." #### File:
 Three\_islands\_ORNITH.kml **Description:** A GIS layer containing
 polygyons with boundaries of the Three Islands Archipelago (Kent Island,
 Hay Island, Sheep Island), NB, CA, and boundaries of the study area. ####
 File: gm\_weather\_ORNITH.csv **Description:** Daily weather data from the
 Environment Climate Change Canada weather station on Grand Manan Island,
 NB, Canada, from 2022 to 2024. Missing values are represented by NA. #####
 Variables * date: Date of observation. * mean_temp_c: Mean temperature on
 the date of observation. * total_precip_mm: Total precipitation, in mm, on
 the date of observation. #### File: deployments\_ORNITH.csv
 **Description:** Dataset containing information about deployments of the
 radio transmitters used to quantify movement behavior, with one record per
 tag deployment. ##### Variables * tag: A character code that uniquely
 identifies each tag deployment record, consisting of the tag number, and,
 if the tag was deployed more than once, a number appended as a suffix to
 the tag number (e.g. "127" and "127.1" represent
 multiple deployments of tag 127). * band_number: The band number of the
 individual that received the tag, which uniquely identifies individual
 fledglings. Most individuals have only one tag deployment, but two
 individuals had two different tag deployments at different times. * year:
 The year in which the tag deployment occurred. * nest_key: The nest key of
 the natal nest of the individual fledgling. * tagged_date: The date on
 which the tag was deployed. * tagged_age: The age at which the tag was
 deployed; "N" indicates the tag was deployed on a nestling,
 "J" indicates the tag was deployed on a juvenile that had
 already fledged. * fate: The fate of the fledgling at the end of the tag
 deployment period. "alive" indicates that the fledgling was
 alive at the end of the period. Fledglings that were "assumed
 dead" or "probably dead" went missing too early to have
 dispersed outside of the detection range; these were assumed to have been
 predated and moved by predators. "dead" indicates the fledgling
 was dead at the end of the period. "dead as nestling" indicates
 individuals that died in the nest, before fledging. "other"
 indicates an individual killed in a mistnet by a herring gull in September
 2024. "tag off" indicates fledglings whose tags were assumed to
 have fallen off, with no evidence of predation. "tangled"
 indicates fledglings whose tags became entangled in vegetation.
 "unknown" indicates fledglings whose fates were uncertain. *
 nest_x: The x coordinate of the fledgling's natal nest, recorded as
 an easting in UTM Zone 19 N. * nest_y: The y coordinate of the
 fledgling's natal nest, recorded as a northing in UTM Zone 19 N. ####
 File: KI.kml **Description:** A GIS layer containing polygyons delineating
 forests, buildings, shorelines, and the outline of Kent Island, NB, CA.
 #### File: pf\_data\_sf\_ORNITH.csv **Description:** Dataset containing
 daily radio telemetry locations of the tracked fledglings, with one record
 representing one location of a given fledgling. NAs represent missing or
 unavailable values. ##### Variables * tag: The tag deployment code of a
 fledgling, corresponding to the "tag" field in the deployments
 database. Uniquely identifies an individual fledgling. * date: The date of
 observation. * time: The time of observation, as hhmm (24-h clock). *
 fate_daily: The fate of the individual on the day of observation.
 "?" indicates uncertain fate. "alive" and
 "dead" indicate the individual was alive or dead, respectively.
 "alive?" indicates the individual was believed to be alive, but
 the fate was somewhat uncertain. "assumed dead" indicates the
 individual disappeared and was assumed dead (see "fate" in the
 deployment dataset). "tag off" indicates the radio transmitter
 was assumed to have fallen off the individual, with no evidence of
 predation. "tangled" indicates that the individual was entangled
 in vegetation. * easting: The x coordinate of the location at which the
 fledgling was observed, recorded as an easting in UTM Zone 19 N. *
 northing: The y coordinate of the location at which the fledgling was
 observed, recorded as a northing in UTM Zone 19 N. * notes.tracks: Notes
 about the observation. * band_number: The band number of the individual,
 which uniquely identifies individual fledglings. * color: The color band
 combination of the individual, with each letter representing a color. May
 not uniquely identify individuals because some combinations were re-used
 after the individual that originally received the combination died.
 Abbreviations represent the plastic color bands given to each individual,
 with letters on the left hand side of the period representing color bands
 on the left leg and letters on the right side representing colors on the
 right leg. A = aluminum, B = black, G = green, L = light blue, N = navy, O
 = orange, R = red, S = striped, V = violet, W = white, Y = yellow. * year:
 The year in which the observation occurred. * nest_key: The nest key of
 the natal nest of the individual fledgling. * tagged_date: The date on
 which the individual received a radio tag. * fledge_date: The date on
 which the individual fledged from its natal nest. * fate_end: The
 individual's fate at the end of the study period (see
 "fate" in the deployments dataset). * fate_date: The date on
 which the individual's final fate ("fate_end") occurred. *
 tagged_age: The age at which the tag was deployed; "N" indicates
 the tag was deployed on a nestling, "J" indicates the tag was
 deployed on a juvenile that had already fledged. * cause_mort: If the
 fledgling died during the study period, its cause of mortality.
 "predated" or "predation" indicate the fledgling was
 known to be predated. "maybe predation" and "probable
 predation" indicate the fledgling was believed to be predated, but
 the cause of mortality was not known with certainty.
 "starvation/exposure" indicates the fledgling died from
 non-predation-related causes, likely starvation, exposure, or disease.
 "tangling" indicates the fledgling died due to entanglement in
 vegetation. NAs mean cause of mortality was not applicable (fledgling did
 not die). - notes.depl: Notes about the tag deployment. - eggs_laid: The
 clutch size of the individual's natal nest. - female_id: The band
 number of the individual's female parent. - male_id: The band number
 of the individual's male parent. - found_date: The date on which the
 individual's natal nest was found. - hatch_date: The date on which
 the first young in the individual's natal nest hatched. -
 eggs_hatched: The number of eggs in the individual's natal nest that
 hatched. - fledglings: The number of young that fledged from the
 individual's natal nest (including the focal individual). -
 mating_status: The mating status of the fledgling's parents; either
 monogamously mated ("MO") or polygynously mated
 ("PG"). - female_number: If the fledglings' parents were
 polygynously mated, female number is "1" if the female was the
 male's primary (first-laying) mate and "2" if the female
 was a secondary (later-laying) mate. If the fledglings' parents were
 monogamously mated, female number is "1" - clutch_number: The
 brood number of an individual's natal nest and whether the nest was a
 replacement brood and/or had uncertainty in its assignment. All codes
 include a brood number: second broods (coded with a "2") are any
 broods attempted by a pair after they fledge one brood of young, which is
 the first brood (coded with a "1"). Addition of "R"
 indicates the brood is a replacement after losing an earlier attempt (e.g.
 "R1" is a replacement of a first brood). Uncertainty in
 assignment is indicated with an E (for "estimated," e.g.
 "ERR1" is the estimated second replacement of a first brood). -
 nest_x: The x coordinate of the fledgling's natal nest, recorded as
 an easting in UTM Zone 19 N. - nest_y: The y coordinate of the
 fledgling's natal nest, recorded as a northing in UTM Zone 19 N. -
 age_at_fldg: The age in days post-hatch at which the individual fledged
 from its natal nest. - weight: The mass of the individual in g when it was
 banded as a nestling, at the age in days post-hatch given in the age in
 days field (see below). - tarsus: The tarsus of the individual in mm when
 it was banded as a nestling, at the age in days post-hatch given in the
 age in days field (see below). - date_measured: The date on which the
 individual was banded as a nestling. - age_in_d: The age in days
 post-hatch on which the individual was banded as a nestling. - sex: The
 sex of the individual, assigned by molecular sex determination.
 "F" = female and "M" = male. - days_pf: The age in
 days post-fledge of the individual on the day of observation. -
 daily_dist: The distance the individual moved in m from its location on
 its last tracking occasion to its location on the day of observation. -
 dist_from_nest: The distance of the individual from its natal nest in m on
 the day of observation. - geometry: Field containing a vector of the
 easting and northing of the individual's location on the day of
 observation. - day: The numeric day of the year on which the observation
 occurred.