DOI: 10.5061/dryad.6hdr7sr6q
title: Data from: Peregrine Falcons shift mean and variance in provisioning in response to increasing brood demand

description: The hierarchical model of provisioning posits that parents employ a
 strategic, sequential use of three provisioning tactics as offspring
 demand increases (e.g., due to increasing brood size and age). Namely,
 increasing delivery rate (reducing intervals between provisioning visits),
 expanding provisioned diet breadth, and adopting variance-sensitive
 provisioning. We evaluated this model in an Arctic breeding population of
 Peregrine falcons (Falco peregrinus tundrius) by analyzing changes in
 inter-visit-intervals (IVIs) and residual variance in IVIs across 7 study
 years. Data was collected using motion-sensitive nest camera images and
 analyzed using Bayesian mixed effect models. We found strong support for a
 decrease in IVIs (i.e., increase in delivery rates) between provisioning
 visits and an increase in residual variance in IVIs with increasing
 nestling age, consistent with the notion that peregrines shift to
 variance-prone provisioning strategies with increasing nestling demand.
 However, support for predictions made based on the hierarchical model of
 tactics for coping with increased brood demand was equivocal as we did not
 find evidence in support of expected covariances between random effects
 (i.e., between IVI to an average-sized brood (intercept), change in IVI
 with brood demand (slope) or variance in IVI). Overall, our study provides
 important biological insights into how parents cope with increased brood
 demand.
description: Data was collected from nest camera images over a period of 7
 consecutive breeding seasons in Rankin Inlet, Nunavut from 2013-2019.
 Cameras were placed within 1m of the nest scrape and data was processed
 post field-season. Please see McKinnon et al., (2024) for the full
 methodological details. 
description: # Data from: Peregrine Falcons shift mean and variance in provisioning in
 response to increasing brood demand
 Complete methods are
 outlined in the publication in Behavioral Ecology ## Description of the
 data and file structure Two files are provided: data file entitled
 'PEFA_provisioning_data_201319.csv' and R Studio file entitled
 'Available_R_code_McKinnonetal2023.R' Descriptions of column
 headings and data coding in the csv file are below. | Column Name |
 Description | Data Type | Values | | ------------- |
 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ------------ | ---------------------------------------------------------------------------- | | scorer  | photo observer | character | Anna, Kevin, Nick, Rebekah | | site | cliff location, same cliff location has same site ID across years | character | site IDs are entered as numerical values, but should be treated as character | | yearsite | unique combination of site and year, within a year, this is a specific pair of PEFA | character | entered as numerical values, but should be treated as character | | chicks | current brood size, if camera trap failed, brood size = NA | numerical | 1,2,3,4, 5 or NA | | cam\_model | model of camera trap | character | HC600 HYPERFIRE, PC800 PROFESSIONAL, PC85 RAPIDFIRE PRO | | motion | motion detection sensitivity settings. When sensitivity was not recorded in camera metadata, motin = unknown. When camera failed, motion = NA | numerical | 50, 75, 100, NA, Unknown | | trigger  | time lapse setting, photos taken every X minutes even without a camera trigger. If camera failed, trigger = NA. If no trigger setting, trigger = no timelapse. If detail not in camera metadata, trigger = unknown. | numerical | 1, 3, 5, 15, NA, no timelapse, Unknown | | hatch\_date | hatch day of first egg | numerical | dd/mm/yyyy | | julian | julian date of hatch date, days since January 1st, 1900 (calculated in Excel) | numerical | | | julian2 | day within the year of hatch date, where January 1st = day 1 | numerical | | | date | date of nest observation | numerical | dd/mm/yyyy | | jdate | julian date of "date" in days since January 1st, 1900 (calculated in Excel) | numerical | | | jdate2 | day within the year of nest observation, where January 1st = 1 | numerical | | | start\_day | nest observation day | numerical | dd | | start\_month  | nest observation month | numerical | mm | | year | nest observation year | numerical | yyyy | | visit\_type | indicates whether provisioning visits could be scored. Yes = provisioning, No = fail (e.g., when camera failed) | categorical | provisioning, fail | | start | time of the start of the nest visit or camera failure | numerical | hh:mm:ss | | sex | sex of parent observed at nest. m = male, f = female, NA = camera failure, unknown = camera photo did not allow sex determination visually | categorical | m, f, NA, unknown | | end\_day | day of the end of the nest visit or camera fail | numerical | dd | | end\_month | month of the end of the nest visit or camera fail | numerical | mm | | supplemented | was the nest supplemented? y =yes, n = no. | catergorical | y, n | ## Code/Software All analyses were completed using the R statistical environment. Complete code including required libraries and packages is provided in the R Studio file entitled ''Available_R_code_McKinnonetal2023.R'