Assessing the impacts of livestock grazing on upland bird breeding territories using drone surveys

Ground nesting birds are sensitive to habitat structure, so understanding this relationship is fundamental to managing habitat to maintain or enhance bird populations. We used an existing long-term, large-scale experiment with routine monitoring of meadow pipit territories to assess the capability of drone-based remote sensing as a means of capturing relevant habitat information. Normalised Difference Vegetation Index (NDVI) captured differences in stocking density between treatments and autumn measured NDVI was well correlated to field measurements of vegetation height and density. Spring and autumn NDVI were negatively correlated due to dominant tussock-forming species dying back over winter. Meadow pipit apparent territory size was positively correlated to autumn NDVI and to the difference between autumn and spring NDVI. Apparent territory size was larger where there was more tussocky vegetation that comprise the areas least preferred for foraging. The long-lived nature of tussocks l..., Study system
The long-term Glen Finglas grazing experiment (56°16’N, 4°24’W) was established in 2002 on a patchwork of upland, unimproved plant communities including upland wet heathland (according to the UK National Vegetation Classification, Rodwell 1991, 1992) mainly (in order of area) U5 Nardus stricta–G. saxatile grassland (Nardus grassland), M15 Scirpus cespitosus (now Trichophorum cespitosum)–Erica tetralix wet heath), the mire communities M6 Carex echinata–Sphagnum recurvum/auriculatum (Carex mire), M25 Molinia caerulea–Potentilla erecta (together with small areas of M23 Juncus effusus/acutiflorus-Galium palustre called Molinia mire in this paper), U4 Festuca ovina–Agrostis capillaris–Galium saxatile grassland (Agrostis-Festuca grassland), and U20 Pteridium aquilinum–G. saxatile (bracken). The climate is cool and humid (mean temperatures for January and July were 3.04 and 14.12°C, respectively, for 1981–2010 and the mean annual rainfall 2,230 mm (Perry and Hollis, 2005), and the..., , # Assessing the impacts of livestock grazing on upland bird breeding territories using drone surveys

[https://doi.org/10.5061/dryad.x69p8czv3](https://doi.org/10.5061/dryad.x69p8czv3)

## Description of the data and file structure

### Files and variables

#### File: Combined\_Plot.csv

**Description:** 

##### Variables

* Block: Experimental block (A to F)
* Treatment: Coded treatment (I High 9 sheep per plot, 2.7 sheep/ha; II Low sheep 3 per plot, 0.9 sheep/ha, III Mixed sheep and cattle, grazing offtake equivalent to II, IV no livestock grazing)
* Plot_ID: Combination of Block and Treatment codes.
* SPR_NDVI_MEAN: Mean NDVI from spring image at the plot level. Unitless, scale -1 to 1.
* SPR_NDVI_STD: Standard deviation of NDVI across the plot in spring. Unitless, scale -1 to 1.
* AUT_NDVI_MEAN: Mean NDVI from autumn image at the plot level. Unitless, scale -1 to 1.
* AUT_NDVI_STD: Standard deviation of NDVI across the plot in autumn. Unitless, scale -1 to 1.
* 2020PinFrameHeight: M...