DOI: 10.5061/dryad.9zw3r22bd
title: Livestock grazing impacts upon components of the breeding productivity of a common upland insectivorous passerine: results from a long-term experiment

description: The intensity of pastoral management in areas of High Nature Value farming
 is declining in some regions of Europe but increasing in others. This
 affects open habitats of conservation concern, such as the British
 uplands, where bird species that benefit from low-intensity grazing may be
 most sensitive to such polarisation. While experimental manipulations of
 livestock grazing intensities have improved our understanding of upland
 breeding bird responses in the short-term, none have examined the
 longer-term impacts of altered management on reproductive success. Using a
 replicated landscape-scale experiment that started in 2003, we
 investigated the effects of four grazing treatments (intensive sheep;
 low-intensity sheep; low-intensity mixed sheep and cattle; and no grazing)
 on the breeding productivity of meadow pipits Anthus pratensis, the most
 common upland passerine. Surveys were carried out systematically during
 early (2003 & 2004) and later (2015 & 2016) sampling
 periods of the experiment to compare the short and longer-term effects of
 grazing treatments on breeding density and productivity of pipits
 specifically, but also on the overall bird community. Pipit breeding
 density was lowest under low-intensity sheep grazing while the highest
 egg-stage nest survival was observed in the same treatment, although no
 significant treatment effects were detected on overall nest survival or
 fledgling output. There were no significant differences in treatment
 effects between the sampling periods on any breeding variable, but overall
 nest survival was lower in the later sampling period across all
 treatments. Breeding bird species richness differed between treatments in
 the later sampling period, with highest species richness in the ungrazed
 treatment. Synthesis and application. Livestock grazing management can
 have different outcomes for different upland birds. With time, meadow
 pipit breeding productivity tended to be higher when sheep grazing
 intensity was reduced and/or mixed with cattle, and lower when livestock
 were removed, but not significantly so. Removal of grazing, however, can
 significantly increase bird species richness. The long-term experiment
 showed an overall decline in fledglings regardless of grazing treatments,
 potentially a result of increased predator numbers harboured by nearby
 developing woodland, highlighting the importance of considering wider
 landscape processes in grazing management decisions.
description: Data organised by breeding parameter.
 Variable headings as in the associated paper, except for Sampling
 period, which is here named "Continuity" where the
 category "Short" corresponds to the early sampling period (2003
 and 2004) and "Long" the later sampling period (2015 and 2016).
 "Territories" refers to meadow pipit breeding territories only,
 and "OtherSpecies_Territories" refers to breeding territories of
 all species except from meadow pipits. "Species" refers to the
 number of breeding bird species, including meadow pipits.