Anthropogenic climate and land-use change drive short- and long-term biodiversity shifts across taxa

Climate change and habitat loss present serious threats to nature. Yet, due to a lack of historical land-use data, the potential for land-use change and baseline land-use conditions to interact with a changing climate to affect biodiversity remains largely unknown. Here, we use historical land use, climate data and species observation data to investigate the patterns and causes of biodiversity change in Great Britain. We show that anthropogenic climate change and land conversion have broadly led to increased richness, biotic homogenization and warmer-adapted communities of British birds, butterflies and plants over the long term (50+ years) and short term (20 years). Biodiversity change was found to be largely determined by baseline environmental conditions of land use and climate, especially over shorter timescales, suggesting that biodiversity change in recent periods could reflect an inertia derived from past environmental changes. Climate–land-use interactions were mostly related to long-term change in species richness and beta diversity across taxa. Semi-natural grasslands (in a broad sense, including meadows, pastures, lowland and upland heathlands and open wetlands) were associated with lower rates of biodiversity change, while their contribution to national-level biodiversity doubled over the long term. Our findings highlight the need to protect and restore natural and semi-natural habitats, alongside a fuller consideration of individual species’ requirements beyond simple measures of species richness in biodiversity management and policy

Data from: Individual consistency of long-distance migration in a songbird: significant repeatability of autumn route, stopovers and wintering sites but not in timing of migration

Through new tracking techniques, data on timing and routes of migration in long-distance migrant birds are accumulating. However, studies of the consistency of migration of the same individuals between years are still rare in small-sized passerine birds. This type of information is important to understand decisions and migration abilities at the individual level, but also for life history theory, for understanding carry over effects between different annual cycle stages and for conservation. We analysed individual repeatability of migration between years in great reed warblers Acrocephalus arundinaceus; a medium-sized European songbird migrating to sub-Saharan Africa. In seven males, with geolocator data from 2–4 yr per bird, we found low to moderate (non significant) repeatability in timing of migration parameters (R ≤ 0.41), but high (and significant) repeatability for most spatial parameters, i.e. autumn route (R = 0.64) and stopover sites (R = 0.59–0.87) in Europe, and wintering sites (R = 0.77–0.99) in sub-Saharan Africa. This pattern of high spatial but low temporal within-individual repeatability of migration between years contrasts other tracking studies of migrating birds that generally have found consistency in timing but flexibility in routes. High spatial consistency of migration in the great reed warbler may be due to it being a specialist in wetlands, an unevenly distributed habitat, favouring a strategy of recurrence at previously visited sites. Low temporal repeatability may be caused by large between-year variation in carry-over effects from the breeding season, high flexibility in decision rules during migration or high sensitivity to environmental factors (weather, wind) during migration

Relating national levels of crop damage to the abundance of large grazing birds: Implications for management

1. Populations of large grazing birds have increased in Europe during the past five decades, raising conflicts between conservation and farming interests. Managing these conflicts requires knowledge about the currently unknown relationship between population sizes and crop damage levels. 2. We analysed unique data on reported, inspected and compensated crop damage caused by geese, swans and cranes together with data from population surveys in Sweden to investigate how bird abundance is related to damage levels at the national scale between 2000 and 2015. 3. Over the study period, the annual number of damage reports, yield loss and costs for compensation increased. These crop damage levels were positively related to national population indices of common crane, barnacle and greylag goose. The shape of these relationships varied between species and encompassed considerable uncertainty. However, on a year-to-year basis (detrended data) we found no evident association between damage levels and bird numbers. 4. Yield loss and compensation costs per reported damage did not increase with higher population indices of greylag goose, but they did so for barnacle goose. 5. Synthesis and applications. We present a novel study of the relationships between different crop damage level indicators (damage reports, yield loss and compensation costs) and population numbers of large grazing birds. We identified a positive relationship with high uncertainty for all cases. We also identified the need to (a) better synchronize the monitoring of damages and bird numbers in time and space and (b) further study the relationships between damage levels and bird numbers at smaller (local and regional) and larger (flyway) spatial scales to reduce the uncertainty of the relationship and to gain a more holistic understanding of the syste

Seeking greener pastures : crop selection by Greylag Geese (Anser anser) during the moulting season

Over the last 40 years, many goose populations have recovered from historic lows and are now more numerous than ever. At the same time, geese have shifted from natural foraging habitats to securing most of their nutritional demands from agricultural fields, leading to crop damage and conflict with agriculture. We studied field use by Greylag Geese (Anser anser) in the agricultural landscape surrounding a main breeding and moulting lake in Sweden. From 2012 to 2016, weekly roadside surveys were conducted from May to July. Data were collected on goose numbers, crop type and sward height in agricultural fields. Using a compositional analysis, we demonstrate that Greylag Geese show a strong selection for ley and pasture fields compared to other crop types (rank order: ley/pasture > oat > barley > wheat > other crops). This selection was consistent across years and between pre- and post-moult. Aside from ley and pasture, no other croptypes were selected for, as they were used less than expected given their availability. Irrespective of crop type, geese foraged predominantly on short (0–10 cm) swards. The strong selection for ley and pasture may have been driven by higher nutritional quality of short, managed grass swards relative to other available foods. This suggests that during the summer grass fields may be more vulnerable to damage compared to other crop types. Our study provides a deeper understanding of the ecology of Greylag Geese, which may be used to inform management strategies focused on mitigating crop damage and alleviating conflict.Under de senaste 50 åren har åtskilliga gåspopulationer återhämtat sig från historiskt låga nivåer till att nu vara större än någonsin. Samtidigt har gäss i stor utsträckning övergivit sina ursprungliga födosöksmiljöer för att numer finna nästan all sin föda på jordbruksmark, något som ibland leder till konflikt på grund av betesskador. Vi studerade grödoval hos gragäss (Anser anser) i ett jordbruksdominerat landskap kring en viktig häcknings- och ruggningssjö i södra Sverige. Från 2012 till 2016 skedde inventeringar från vägar i studieområdet varje vecka under maj, juni och juli. Vi noterade antalet gäss, grödoslag och grödohöjd på alla fält med gragäss. Statistiska analyser (compositional analysis) visade att grägässen starkt föredrog fält med vall eller betesmark framför andra grödor (preferensordning: vall/betesmark > havre > korn > vete > övriga grödor). Preferensmönstret var det samma oberoende av år och period under sommaren (före resp. efter ruggning). Alla andra grödoslag än vall och betesmark var icke föredragna, eftersom de utnyttjades mindre än deras andel av studieområdet. Den starka preferensen för vall och betesmark kan vara en följd av en högre näringsmässig kvalitet hos gräs som ännu inte blivit högvuxet. Detta antyder i sin tur att fält med kort gräs är mer utsatta för gåsbete än andra grödor under sommarmånaderna. Denna studie ger ny kunskap om grágässens uppträdande på jordbruksmark under senvår och sommar, vilken kan ge förbättrade förvaltningsstrategier för att minska betesskador och reducera konflikten med jordbruksintressen