DOI: 10.5061/dryad.2547d7wmn
title: Data from: Incubation recess behaviors influence nest survival of Wild Turkeys

description: In ground nesting upland birds, reproductive activities contribute to
 elevated predation risk, so females presumably use multiple strategies to
 ensure nest success. Identification of drivers reducing predation risk
 have primarily focused on evaluating vegetative conditions at nest sites,
 but behavioral decisions manifested through movements during incubation
 may be additional drivers of nest survival. However, our understanding of
 how movements during incubation impact nest survival is limited for most
 ground nesting birds.  Using GPS data collected from female
 Eastern Wild Turkeys (n = 206), we evaluated nest survival as it relates
 to movement behaviors during incubation, including recess frequency,
 distance traveled during recesses, and habitat selection during recess
 movements. We identified 9,361 movements off nests and 6,529 recess events
 based on approximately 62,065 hours of incubation data, and estimated mean
 nest attentiveness of 84.0%.  Numbers of recesses taken daily
 were variable across females (range: 1‒7). Nest survival modeling
 indicated that  increased cumulative distance moved during
 recesses each day was the primary driver of positive daily nest survival.
 Our results suggest behavioral decisions are influencing trade-offs
 between nest survival and adult female survival during incubation to
 reduce predation risk, specifically through adjustments to distances
 traveled during recesses.
description: We monitored live‒dead status daily during the reproductive
 season using handheld Yagi antennas and R4000 (Advanced Telemetry Systems,
 Inc., Isanti, MN) or Biotracker receivers (Biotrack Ltd., Wareham, Dorset,
 UK). Live-dead status was determined via GPS‒VHF transmitter mortality
 signals scheduled to activate if stationary for 24 hours. We downloaded
 GPS locations ≥ 1 per week via a VHF/UHF handheld command unit receiver
 (Biotrack Ltd., Wareham, Dorset, UK). We viewed GPS locations and
 determined incubation when female locations became concentrated around a
 single point for 1‒2 days (Collier and Chamberlain 2011, Conley et al.
 2015, Yeldell et al. 2017, Wood et al. 2018). Nesting females were not
 disturbed or flushed from nest sites during monitoring, but instead were
 live‒dead checked daily via VHF from a distance of &gt; 20 m.Our nest
 monitoring data produced a ragged telemetry dataset (Rotella et al. 2004),
 and we used the nest survival approach outlined by (Dinsmore et al. 2002) to
 evaluate influences of incubation recess movements on daily nest
 survival.  The ragged telemetry approach serves as a general model for
 known fate data in program MARK (White and Burnham
 1999) when loss date may not be known exactly and
 is flexible for integrating time‒dependent individual covariates (Rotella et al. 2004,
 Collier et al. 2009). For
 each nesting female, we created an encounter history for the entire
 incubation period and scaled each nesting event (<i>k </i>= 1)
 to the same start point, as evaluating temporal variation in nest survival
 was not our objective (Dinsmore et al. 2002).  We recorded the last day
 each nest was known to be alive (<i>l</i>) and the final date
 that the female incubated (<i>m</i>) based on our VHF and GPS
 data (Conley et al. 2015, Conley et al. 2016, Yeldell et al. 2017) and
 assigned each nest a fate of 0 = survived or 1 = failed.  We followed the
 approach of Collier et al. (2009), and developed time dependent covariates
 for both the daily frequency and distance of recess movements, and
 time‒dependent covariates for the cumulative values of daily frequency and
 distance of recess movements.  We developed a set of candidate models
 which we used to evaluate time‒specific variation in wild turkey behaviors
 to better understand how variation in behavioral decisions during
 incubation drive nest survival.  Underlying our work was the hypothesis
 that behavioral changes, manifested via the movement ecology of wild
 turkeys during nesting, would impact nest success.  Our initial
 expectation was that, generally, increased movements would increase the
 level of attention on the landscape, which would thus increase nest
 failure.  As such, we included models evaluating fully time‒dependent
 covariates for daily frequency of recess movements and daily distance of
 recess movements, as well as cumulative frequency and distance of recess
 movements (Franklin 2001, Collier et al. 2009).  We also developed
 time-specific trend models for cumulative frequency of recesses and
 distance of recess movements, which assumed that the effect of each
 covariate did not vary by day and was thus constant over time (Franklin
 2001). We used an information‒theoretic approach (Burnham and Burnham
 2002) to rank candidate models and assess model strength (based on
 ΔAIC<sub>c</sub>) using the standard from Burnham and Anderson
 (2002), and estimated daily nest survival for the best fitting candidate
 model given the data.
description: <strong>Wild turkey
 nest survival dataset</strong> Data column description for
 program MARK analysis. FirstFound – The day the nest was
 first found. LastPresent – The day the
 individual was last present at the nest site. LastCheck – The last day the nest was
 checked. Fate –
 Whether the nest was successful or failed during incubation. 1 =
 successful, 0 = failed. Attempt – The number of nesting
 attempt associated to that occasion. ID – The unique number used to
 identify individuals captured. Freq – Capture history for each
 individual. r1:r29 – The cumulative number of
 recesses taken away from the nest on that given day of incubation. r1 =
 day 2, r29 = day 28. dd1:dd29 – The cumulative average
 daily distance moved during the incubation period. dd1 = day 2, dd29 = day
 28. rr1:rr29 –
 The number of recesses on that given day of incubation. rr1 = day 2, rr29
 = day 28. d1:d29
 – The average daily distance moved during that given day of incubation. d1
 = day 2, d29 = day 28.