Dataset DOI: 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.