DOI: 10.5061/dryad.7012f1b
title: Data from: Variation in offspring development is driven more by weather and maternal condition than predation risk

description: 1. Variation in offspring development is expected to be driven by
 constraints on resource allocation between growth and maintenance (e.g.,
 thermoregulation). Rapid post-natal development decreases predation risk,
 while inclement weather likely prolongs development. For taxa with
 parental care, parental behaviour may buffer offspring against some
 extrinsic drivers. 2. Using a 7-year dataset from an alpine population of
 horned lark Eremophila alpestris, a ground-nesting songbird in northern
 British Columbia, Canada, we investigated multiple potential drivers of
 variation in incubation and nestling development duration. 3. Using path
 analysis, we evaluated the direct effects of weather, predation risk, and
 parental care on offspring development, as well as, indirect developmental
 ‘carry-over’ effects of conditions during incubation on the nestling
 period. 4. Nestling period duration varied by nearly 100% (7–13 days) and
 incubation duration by 40% (10–14 days). Cold ambient temperatures late in
 the nestling period prolonged development by 1 day for every 2 days below
 10°C; particularly when combined with heavy precipitation. Rapid nestling
 development was associated with high predation risk, and prolonging
 development incurred a nest survival cost (–2.3%/day). Females in good
 condition created nest environments that promoted rapid nestling
 development periods (average = 8–9 days) compared to poor condition
 females during harsh, early-season conditions (10–11 days), indicating
 buffering capabilities against environmental constraints. Incubation
 duration was only weakly correlated with fledging age (r = –0.21)
 suggesting minimal developmental carry-over effects. 5. Given high nest
 predation risk, immediate fitness benefits can be derived by overcoming
 environmental constraints and reducing development time. While predation
 risk was influential, inclement weather and maternal condition had
 stronger effects on within-population variation in development time. We
 highlight the importance of addressing multiple drivers of variation in
 key life-history traits and provide context for understanding life-history
 theory under changing environmental conditions.
description: Development time for an
 alpine population of Horned LarkData was collected in
 the field from 2003 to 2011 by Alaine Camfield, Elizabeth MacDonald, and
 Kathy Martin. The variables 'Clutch initiation',
 'Incubation initiation', 'Hatch date', and
 'Fledge date' are in Julian date format. 'Predation
 risk' is the probability of nest loss per month calculated using the
 Mayfield estimate.Weather data for Hudson
 Bay Mountain, 2003-2011Temperature and
 precipitation data collected on Hudson Bay Mountain (alpine field site)
 over the years 2003, 2004, 3005, 2006, 2007, 2010, and 2011. Data was
 collected by Alaine Camfield, Kathy Martin and Will MacKenzie. SA stands
 for 'Smithers Airport' which was the closest weather station
 with available precipitation data early in the study when precipitation
 was not available for the study site. See associated paper for more
 details.Weather data for Hudson Bay
 Mountain_2003 to 2011.xlsx