DOI: 10.5061/dryad.stqjq2cbz
title: Data from: Long-term tracking captures the timing of ontogenetic niche shifts in Northeast Pacific white sharks

description: Ontogenetic changes in area use, habitat use, and trophic interactions
 play an important role in the ecology, demography, and ultimately
 population dynamics of many species. Assumed to be driven by shifting
 life-history requirements, trophic niche shifts in white sharks
 (Carcharodon carcharias) are well documented, but the timing of the
 spatial niche shift that is hypothesized to occur with the trophic niche
 shift remains poorly understood. To document how fine-scale area use
 varies as sharks age and the timing of the ontogenetic spatial shift of
 this top predator, we tracked individual white sharks tagged as
 young-of-the-year or young juveniles over multiple years. Using data from
 juvenile white sharks detected over multiple years in a nursery habitat
 with a high-density receiver array, we found no difference in area use
 with age. However, using a coast-wide receiver array including nursery and
 adult habitat, we found the probability of detecting a juvenile white
 shark in nursery habitat decreased with age, with a concurrent increasing
 probability of detection in adult habitat. As the conservation and
 management of this species relies on understanding nursery habitat use and
 age-related movements, data presented here address an important knowledge
 gap for the understudied juvenile to sub-adult life stages and the
 ontogenetic habitat shift of this species.
description: # Data from: Long-term tracking captures the timing of ontogenetic niche
 shifts in Northeast Pacific white sharks ## Description of the data and
 file structure In "Logan et al_JWS_PresenceAbsence_df.csv" Date
 - Date (mm/dd/YYYY) Shark - Unique identifier for each shark of the
 dataset, unique for each individual Dect - binary variable for if a the
 shark was detected on a given day. 0 = not detected, 1 = detected. Can be
 detected anywhere on the array. NumDect - Number of detections recorded
 during that day for that individual. If detected over multiple regions in
 a day, the region where the most detections occur is reported (mode of
 detection regions). Age - Estimated age of the individual (years).
 Calculated from the total length of the shark at tagging (to assign age at
 tagging using von Bertallanffy growth curve parameters) plus the number of
 days passed since tagging. See text for additional detail. Sex - Sex of
 the shark determined at time of tagging. TagMethod - The method used for
 tagging the individual shark. See text for more details. Region - Region
 where the detection(s) occurred for the given date. If detected over
 multiple regions in a day, the region where the most detections occur is
 reported (mode of detection regions). If NA, no detection occurred for the
 given day. Length - Estimated length of the individual (cm) based on the
 size at tagging and the number of days since tagging using von
 Bertallanffy growth curve parameters. See text. In "Logan et
 al_HighRes_VPS_df.csv", each row holds information about 1 individual
 dive DateTimeUTC - date and time of a rendered VPS position in UTC format
 (mm/dd/yyyy hh:mm:ss) shark - Unique identifier for each shark of the
 dataset, unique for each individual Transmitter - Transmitter ID for each
 individual shark lat - latitude of the rendered VPS position in decimal
 degrees lon - longitude of the rendered VPS position in decimal degrees
 HPE - Horizontal Positional Error of the rendered VPS position (unitless
 measure). Provided by Innovasea upon data rendering. sex - sex of the
 shark determined during tagging. TNL_cm - Total natural length (cm) of the
 shark determined during tagging. X - transformed coordinate for latitude
 in Mercator projection (meters) EPSG 3857 Y - transformed coordinate for
 latitude in Mercator projection (meters) EPSG 3857 age - Estimated age of
 the individual (years). Calculated from the total length of the shark at
 tagging (to assign age at tagging using von Bertallanffy growth curve
 parameters) plus the number of days passed since tagging. See text for
 additional detail. daily_length - Estimated total length (cm) of the
 individual based on the size at tagging and the number of days since
 tagging using von Bertallanffy growth curve parameters. See text.
 sizeclass - categorical variable for binning the size (cm; total length)
 of each shark for each detection day. Bins include 100-200, 200-250,
 250-300, 300-350, 350-400, 400+ ageclass - categorical variable for
 binning the age (years) of each shark for each detection day. Bins include
 YOY (young of the year), 1, 2, 3, 4, 5, 6, 7, 8, 9. dailyres - Daily
 residency index to the VPS array. Calculated as the number of hours
 detected in the VPS array divided by 24. ## Sharing/Access information
 please email the lead author, Ryan Logan,
 [rklogn@gmail.com](mailto:rklogn@gmail.com) with any questions or for
 additional information/data.