DOI: 10.5061/dryad.hx3ffbgpw
title: Temperature drives inter-annual variation in badger (Meles meles) predation of lapwing (Vanellus vanellus) on Scottish hill-edge farmland

description: Wading birds have declined globally with particularly in western Europe.
 Multiple species are now on the IUCN Red list, with northern lapwing
 (Vanellus vanellus) near-threatened and declining. Historically, habitat
 degradation, including from wetland drainage and agricultural
 intensification, has contributed to population declines. More recently,
 declines have been attributed to poor breeding success due to
 unsustainably high rates of predation on eggs and chicks, by avian and
 mammalian predators. In the UK, the red fox (Vulpes vulpes) is a major
 mammalian predator of waders, but the Eurasian badger (Meles meles) has
 increased in range and abundance, and can occur at high densities, with
 potential for acute local predation impacts on vulnerable wader
 populations. However, factors affecting rates of badger predation on wader
 nests remain unexplored. We investigate what these factors might be using
 data from six years of lapwing nest monitoring at a breeding site in
 northeast Scotland. The overall probability of badger predation was above
 0.1 when mean daily temperature was below 4 °C during the preceding 7
 days, dropping close to zero when above 10 °C. Badger predation on lapwing
 clutches also increased with earthworm availability, and inter-annual
 effects were observed matching variations in temperature, whereby intense
 badger predation in 2021 coincided with unseasonably cold temperatures and
 low lapwing breeding productivity. This highlights the potential for
 weather forecasting to be used to deploy pre-emptive non-lethal management
 strategies to mitigate badger predation impacts on lapwing nests.
description: <strong>Lapwing nest direct
 observation</strong> To monitor lapwing nests,
 potential wader habitat was surveyed on foot, during the wader breeding
 season (March to July; earliest start date = 30 March; latest end date = 3
 July) over six years, between 2018 and 2023. Routine vehicular farm
 surveys were used initially to locate nests at the start of the breeding
 season every year by observing adult activity, including nest concealment
 and protection behaviours commonly indicative of nesting (Królikowska et
 al., 2016). Survey start points were additionally selected from previous
 observations of activity and nests, as lapwing are highly nest-site
 faithful and philopatric (Thompson et al. 1994; Jarrett et al., 2017).
 Once a lapwing nest was discovered, the date, time, location, number of
 eggs, field number, nest number, nest stage/outcome (still nesting,
 hatched, failed), and reason for failure where applicable, were recorded
 on Epicollect, version 4.2.0 (Epicollect5, 2022). A rough estimate of
 likely hatch date was noted when nests were found during the egg-laying
 phase, based on the presumption of laying one egg per day followed by a 27
 day incubation period (Witherby et al., 1940). Failed nests were inspected
 for field signs of predation, and predator identity was ascertained where
 possible. Badger predation was determined using multiple field sign cues.
 Firstly, nocturnal predation (timings determined from regular surveying)
 implicated mammalian rather than avian predators (Bolton et al., 2007).
 Nocturnal predation events were substantially less likely to be due to
 foxes than badgers as a result of lethal fox control that was conducted on
 site for the entirety of the study. Direct evidence of badger predation
 included signs of exceptional disturbance at the nest site, crushing
 damage to surrounding nest vegetation, whole clutch removal, evidence of
 eating <em>in-situ </em>and distinctive claw marks/scratchings
 around the predated nests in instances where the terrain enabled this to
 be seen. These signs of a high level of nest disturbance were
 characteristic of badger, and absent when nest predation was due to other
 mammalian species <em>e.g. </em>stoats or weasels (Green et
 al., 1987, Valkama & Currie, 1999; Whittingham et al., 2002;
 Stillman et al. 2006). which These signs differ, for example, from partial
 clutch removal, large eggshell remains and large pecked holes in eggs
 without tooth marks indicative of corvids or other avian predators (Green
 et al., 1987; Jackson & Green, 2000; Wallander et al. 2006). These
 signs were consistent with photographic evidence of active predation
 obtained from nests monitored with trail cameras. If evidence was deemed
 not clear, predator identity was not attributed to species but recorded as
 unknown, unknown mammal or unknown avian predation accordingly.
 Nests were marked with a short stake (bearing the ID number),
 which was placed ≥1.5 m away to the north of the nest. Stakes were
 purposefully unobtrusive to prevent an impact of marking itself on nest
 outcomes (Kragten & de Snoo, 2008). Subsequent observations were
 regularly conducted using binoculars or spotting scopes, from a vantage
 point approximately 100-150 m away from the nest, to avoid disturbance.
 This allowed observers to establish an “end” date for each nest,
 <em>i.e.</em>, the point at which the nest either hatched or
 failed. Evidence of hatching included small chippings of eggshell in the
 nesting material (Berg et al., 1992), the presence of hatched chicks
 within the nests, and of identifiable young broods based on regular
 observations (<em>e.g.</em> where broods could be clearly
 distinguished by age, the presence of ringed adults, or newly hatched
 broods in fields where only the one hatched nest was present).Where it was
 not possible to ascertain an outcome, nest fate was assigned as ‘unknown’.
 Following hatching, observers continued to monitor broods as accurately as
 possible, including by colour-ringing chicks and some adults (variable
 across study years) in addition to regular surveys of the whole farm,
 recording all observed chicks (including age estimatiio based on size and
 apparent feather development) and adults. Final observations were
 conducted as soon as possible after fledging, to prevent inflation of
 fledgling counts due to influx from neighbouring breeding areas (as
 cautioned by Bolton et al., 2011). <strong>Trail
 camera surveys</strong> From 2018 to 2021, a
 sample of nests were monitored with a limited number of trail cameras
 based on whether they were likely to be obscured when observed from afar
 with binoculars or spotting scopes. From 2022 a greater availability of
 trail cameras meant more nests were monitored with cameras applied if
 available regardless of nest location. Cameras were set to capture still
 images on low sensitivity, to preserve battery life.. From 2021 onwards,
 these were Browning TM Recon Force Elite HP4 (One Browning Place, Morgan,
 Utah, 84050, USA); and between 2018 and 2021, either Ltl Acorn 6310 (Ltl
 Acorn, 4100 Gannett Avenue, Des Moines, Iowa, 50321, USA) or Reconyx
 Hyperfire 2 Covert IR (3828 Creekside Lane, Ste 2 Holmen, Wisconsin,
 54636, USA). Once nests had completed, cameras were retrieved and
 re-deployed. Images were subsequently reviewed, the time of hatch or
 failure and the outcome of each nest were recorded, together with predator
 identity (where possible) for each predation event. Predation events were
 identified via images of egg removal, of the predator’s head within the
 nest cup, or other clear signs of active predation.
 <strong>Weather data</strong>
 Weather data were sourced from the onsite GWSDF Auchnerran
 Automatic Weather Station (AWS), deployed and remotely managed by the
 James Hutton Institute, Banchory, Aberdeenshire. Temperature (°C) was
 collected using a 107 Air temperature probe, and rainfall (mm) using a ARG
 100 tipping bucket Rain Gauge (0.2 mm/tip) (Campbell Scientific, 80
 Hathern Road, Shepshed, LE12 9GX, UK). Owing to various contemporaneous
 and time-lagged effects of weather on badger activity documented in other
 studies (<em>e.g.</em>, Noonan et al., 2015), weather
 variables were summarised as mean daily temperature and total rainfall
 across two time periods: i) 7-day interval before hatch or failure; and
 ii) 30-day interval before hatch or failure.
 <strong>Invertebrate sampling and land use
 data</strong> Potential additional covariates
 relating to land use and management were sourced from farm records at
 field level (Table 1) and included in statistical models. These included
 invertebrate abundance data and field classifications under the
 Agri-environment Climate Scheme (AECS) (full details for the latter given
 in SI Table 1). Invertebrate data were derived from soil sampling in wet
 weather and conducted annually in June 2018, 2019, and 2021. Two samples
 with dimensions 20 cm x 20 cm x 20 cm per hectare were collected from all
 fields (651 samples in total); all invertebrates in each sample were
 identified to at least family level where possible, and number of
 individuals counted. This procedure yielded relative abundance data for
 invertebrates overall (INV), and for earthworms (EARTH) separately,
 providing a measure of the availability of each to badgers during the
 wader breeding season.
description: # Temperature drives inter-annual variation in badger (Meles meles)
 predation of lapwing (Vanellus vanellus) on Scottish hill-edge farmland
 [https://doi.org/10.5061/dryad.hx3ffbgpw](https://doi.org/10.5061/dryad.hx3ffbgpw) ## Description of the data and file structure ### Files and variables #### File: LapwingNestFate\_JAB\_DataAvailability.csv **Description:**  | Field | Descriptors | | :------------ | :-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | Nest ID | Alphanumeric identifier for each individual nest found at GWSDF Auchnerran 2018 - 2023. | | Camera | Whether a trail camera was present on a nest (TRUE = Present, FALSE = Absent) | | NoCamera | For nests without a trail camera where there was either an exact completion date known (Known Completion Date), or insufficient evidence from the annual data records (No Information). All other nests value = N/A | | CameraFailure | Whether a trail camera failed before nest completion (TRUE = Failure, False = No Failure, N/A = Nests with no trail camera present) | | FateWhenFound | Whether the nest outcome was known at the time of nest discovery, e.g. already hatched/failed. (Nests where fate was known = TRUE, nests where fate was not known = FALSE) | | Fate | Hatch = At least one egg hatched from nest, Badger = Nest predated by badger, Other Mammal = Nest predated either by unidentified mammal or by mammal other than a badger, Avian = Nest predated by avian predator e.g. corvid or gull, Pred. Unknown = Predated by an unidentified predator, Abandoned = Nest abandoned by adult bird before completion, Farm Activities = Nest destroyed by farm activities e.g. ploughing or rolling, Livestock = Nest crushed or destroyed by livestock, Other Failure = Other unidentified cause of failure, Unknown = Unknown outcome | | Year | Year in which breeding attempt occurred | | Field ID | Alphanumeric code identifying each individual field on the farm in which a nest was found | | AECS | Agri Environment Climate Scheme categorisation for each individual field on the farm per year in which a nest was found | | Earth | Estimated number of earthworms per field per year,  estimate calculated from soil samples taken  | | Inv | Estimated number of invertebrates per field per year, estimate calculated from soil samples taken  | | 7\_temp | Mean daily temperature (degrees C) over the 7 days prior to hatching/failing ('end date') | | 7\_RF | Mean daily rainfall (mm) over the 7 days prior to hatching/failing ('end date') | | 30\_temp | Mean daily temperature (degrees C) over the 30 days prior to hatching/failing ('end date') | | 30\_RF | Mean daily rainfall (mm) over the 30 days prior to hatching/failing ('end date') | | exp\_temp | Mean daily temperature (degrees C) over the entire exposure period for each nest ('date found to end date') | | exp\_RF | Mean daily rainfall (mm) over the entire exposure period for each nest ('date found to end date') | | Comp. Date | Date of nest completion (if exact date was unknown, mid point between last visit and visit where nest is completed is taken) Nests found already hatched/failed have date found recorded, unknown outcomes have last check date recorded. | | V1 Date | Date a nest was first visited (found) If completed (Hatch/Fail) no further visit dates recorded  | | V2 Date | Date of second visit to a nest. If completed (Hatch/Fail) no further visit dates recorded | | V3 Date | Date of third visit to a nest. If completed (Hatch/Fail) no further visit dates recorded  | | V(x) Date | Date of (x) visit to a nest. If completed (Hatch/Fail) no further visit dates recorded  |