Bending the curve of terrestrial biodiversity needs an integrated strategy Summary paragraph Increased efforts are required to prevent further losses of terrestrial biodiversity and the ecosystem services it provides 1,2. Ambitious targets have been proposed, such as reversing the declining trends in biodiversity 3-yet, just feeding the growing human population will make this a challenge 4. We use an ensemble of land-use and biodiversity models to assess whether (and if so, how) humanity can reverse terrestrial biodiversity declines due to habitat conversion, a major threat to biodiversity 5. We show that immediate efforts, consistent with the broader sustainability agenda but of unprecedented ambition and coordination, may allow to feed the growing human population while reversing global terrestrial biodiversity trends from habitat conversion. If we decide to increase the extent of land under conservation management, restore degraded land, and generalize landscapelevel conservation planning, biodiversity trends from habitat conversion could become positive by mid-century on average across models (confidence interval: 2042-2061), but not for all models. Food prices could increase and, on average across models, almost half (confidence interval: 34-50%) of future biodiversity losses could not be avoided. However, additionally tackling the drivers of landuse change may avoid conflict with affordable food provision and reduces the food system's environmental impacts. Through further sustainable intensification and trade, reduced food waste, and healthier human diets, more than two thirds of future biodiversity losses are avoided and the biodiversity trends from habitat conversion are reversed by 2050 for almost all models. Although limiting further loss will remain challenging in several biodiversity-rich regions, and other threats, such as climate change, must be addressed to truly reverse biodiversity declines, our results show that bold conservation efforts and food system transformation are central to an effective post-2020 biodiversity strategy. Reversing biodiversity trends by 2050 Without further efforts to counteract habitat loss and degradation, we projected that global biodiversity will continue to decline (BASE scenario; Fig. 1). Rates of loss over time for all nine BDIs in 2010-2050 were close to or greater than those estimated for 1970-2010 (Extended data Extended Data Table 1). For various biodiversity aspects, on average across IAM and BDI combinations, peak losses over the 2010-2100 period were: 13% (range: 1-26%) for the extent of suitable habitat, 54% (range: 45-63%) for wildlife population density, 5% (range: 2-9%) for local compositional intactness , 4% (range: 1-12%) for global extinctions, and 4% (range: 2-8%) for regional extinctions (Extended Data Table 1). Percentage losses were greatest in biodiversity-rich regions (Sub-Saharan Africa, South Asia, South East Asia, the Caribbean and Latin America; Extended Data Fig. 2). The projected future trends for habitat loss and degradation and its driv...

1. European hares Lepus europaeus have declined throughout Europe since the 1960s. Possible reasons for this include agricultural intensification and changes in climate and predator numbers, but no clear consensus has been reached as to the relative importance of each of these. We aimed to identify factors associated with high and low hare numbers throughout Europe, to determine which could have caused population declines. 2.Results of 77 research papers from 12 European countries were summarized. Relationships between hare density and demographics and habitat, climate, hunting and predator variables were examined and quantified where possible. Temporal changes in factors identified as being associated with high or low numbers of hares were then examined to see if they could explain population declines. 3. Data from pastural habitats were limited, but densities of hares were low. Arable habitats had higher densities than mixed areas in spring, unless farming was intensive in which case densities were similar. In autumn the two habitats had similar densities. Field size, temperature, precipitation and hunting had no effect on density throughout Europe. Fecundity was affected by climate. 4. Arable land, various crops, fallow habitat and temperature were positively associated, and monoculture, precipitation and predators negatively associated with hare abundance. The relationship of field size, pasture and woodland with abundance depended on spatial scale. 5. Habitat changes caused by agricultural intensification are the ultimate cause of hare population declines. Effects of changes in climate or predator numbers are magnified by the loss of high-quality year-round forage and cover. Further research is required on how habitat changes affect fecundity and survival, and to identify which parameters have the greatest impact on population numbers. Farmland management policies that target the reestablishment of some of the habitat diversity lost within fields, farms and landscapes will help to reverse the decline of the European hare.

Summary 1.Questionnaires, or social surveys, are used increasingly as a means of collecting data in ecology. We present a critical review of their use and give recommendations for good practice. 2. We searched for papers in which questionnaires were used in 57 ecological academic journals, published over the period [1991][1992][1993][1994][1995][1996][1997][1998][1999][2000][2001][2002][2003] inclusive. This provided a total sample size of 168 questionnaires from 127 papers published in 22 academic journals. 3. Most questionnaires were carried out in North America and western Europe, and addressed species-level issues, principally focusing on mammals. The majority were concerned with impacts of species and/or their conservation, and just under half with human-wildlife interactions. 4. Postal survey was the method used most frequently to carry out the questionnaires, followed by in-person interviews. Some questionnaires were conducted by telephone, and none was web-based. 5. Most questionnaires were concerned with obtaining factual information or perceptions of facts. Ground-truthing (independent verification of the facts) was carried out in less than 10% of questionnaires. 6. The mean ( ± SE) sample size (number of respondents) per questionnaire was 1422 ± 261 and the average ( ± SE) response rate was 63 ± 3%. These figures varied widely depending on the methods used to conduct the questionnaire. 7. The analysis of data was mostly descriptive. Simple univariate methods were the most frequently used statistical tools, and data from a third of questionnaires were not subjected to any analysis beyond simple descriptions of the results. 8. Synthesis and applications. We provide recommendations for best practice in the future use of questionnaires in ecology, as follows: (i) the definition of the target population, any hypotheses to be tested and procedures for the selection of participants should be clearly documented; (ii) questionnaires should be piloted prior to their use; (iii) the sample size should be sufficient for the statistical analysis; (iv) the rationale for the choice of survey method should be clearly stated; (v) the number of non-respondents should be minimized; (vi) the question and answer format should be kept as simple as possible; (vii) the structure of the questionnaire and the data emerging from it should be unambiguously shown in any publication; (viii) bias arising from non-response should be quantified; (ix) the accuracy of data should be assessed by ground-truthing where relevant; (x) the analysis of potentially interrelated data should be done by means of modelling. Researchers should also consider whether alternative, interpretative methods, such as in-depth interviews or participatory approaches, may be more appropriate, for example where the focus is on elucidating motivations or perceptions rather than testing factual hypotheses.

Summary1. Agricultural intensification has had dramatic effects on farmland biodiversity and has caused declines in many taxa. Habitat changes are thought to be the main cause of the decline in numbers of European hares, Lepus europaeus , throughout Europe. In Britain there is greater potential to increase hare numbers in pastural landscapes than in arable landscape. Hares in pasture have lower population densities, poorer body condition and participate less in breeding than in arable habitats. We aimed to investigate habitat selection and home range size in a mainly pastural area in order to reveal why the habitat is suboptimal, and how it could be managed to benefit the species. 2. A seasonal radio-tracking study was used to determine the importance of heterogeneity at the between-and within-habitat scales. Habitat selection by active and resting hares was quantified. Selection was investigated by categorizing habitats by type, and by structure in terms of vegetation height. 3. Mean home range size was 34 ha. Winter and spring ranges were larger than summer and autumn ranges. Hares selected fallow land and pasture grazed by cattle in preference to arable crops throughout the year, except during the winter when crops were suitable as forage. Pasture grazed by sheep was avoided in all seasons but winter. Heterogeneity at the between-habitat scale was less important to hares than heterogeneity at the within-habitat scale in the pastural landscape studied. 4. Hares selected habitats with taller vegetation during the spring and summer. Many of the habitats selected were heterogeneous in structure mainly due to cattle grazing, and hares avoided short homogeneous vegetation in all seasons. Hares are more likely to be limited by habitat in terms of cover than food in these landscapes. 5. Synthesis and applications . Increasing habitat heterogeneity at the farm scale may benefit hares, especially in highly homogeneous, intensively managed landscapes. However, managers of pastural farmland should aim to increase habitat heterogeneity at the within-habitat (or within-field) scale in particular, to provide better cover throughout the year. Agri-environment schemes should target the regeneration of heterogeneity in pastural landscapes, by encouraging changes such as an increase in fallow land and a reduction in livestock density. Such shifts in management are likely to benefit both hares and farmland biodiversity in general.

Insects are the principal food for many animals, including bats (Chiroptera), and all species of bats in the United Kingdom feed over agricultural habitats. Bat populations are declining throughout Europe, probably in part as a result of agricultural intensification. Organic farming prohibits the use of agrochemicals, a major component of agricultural intensification, making it an ideal control for a study of intensive agricultural systems. To evaluate the impact of agricultural intensification on bat foraging, we quantified the availability of bat prey by comparing nocturnal aerial insects captured within habitats on 24 matched pairs of organic and conventional farms. Insects were identified to family and moths to species. We compared the abundance of 18 insect families commonly eaten by bats in the United Kingdom between farm types and tested for correlations of abundance with bat activity. Insect abundance, species richness, and moth species diversity were significantly higher on organic farms than on conventional farms. Insect abundance was significantly higher in pastural and water habitats on organic farms than in the same habitats on conventional farms. Of the 18 insect families that are important components of the bat diet, 5 were significantly more abundant on organic farms overall. Some were also more abundant within organic pastural, woodland, and water habitats than on conventional farmland habitats. The activity of bats that mainly ate Lepidoptera was significantly correlated with the abundance of this order. Our observations suggest that agricultural intensification has a profound impact on nocturnal insect communities. Because bats are resource limited, a reduction in prey availability through agricultural intensification will adversely affect bat populations. Less-intensive farming benefits British bat populations by providing and maintaining diverse and structurally varied habitats, which in turn support a wide selection of insect prey for bats, including insect families that are significant components of the diet of a number of rare bat species.Abundancia y Riqueza de Especies de Insectos Nocturnos en Granjas Orgánicas y Convencionales: Efectos de la Intensificación Agrícola sobre el Forrajeo de Murciélagos Resumen: Los insectos son el alimento principal de muchos animales, incluyendo murciélagos (Chiroptera), y todas las especies de murciélagos en el Reino Unido se alimentan en hábitats agrícolas. Las poblaciones de murciélagos están declinando en toda Europa, en parte probablemente debido a la intensificación agrícola. La agricultura orgánica prohíbe el uso de agroquímicos, un componente mayor de la intensificación agrícola, haciéndolos un control ideal para un estudio de sistemas agrícolas intensivos. Para evaluar el impacto de la intensificación agrícola sobre el forrajeo de murciélagos, cuantificamos la disponibilidad de sus presas mediante la comparación de insectos aéreos nocturnos capturados en hábitats en 24 pares similares de granjas orgánicas y convencionales. Los insectos fueron iden...

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Automated remote ultrasound detectors allow large amounts of data on bat presence and activity to be collected. Processing of such data involves identifying bat species from their echolocation calls. Automated species identification has the potential to provide more consistent, predictable, and potentially higher levels of accuracy than identification by humans. In contrast, identification by humans permits flexibility and intelligence in identification, as well as the incorporation of features and patterns that may be difficult to quantify. We compared humans with artificial neural networks (ANNs) in their ability to classify short recordings of bat echolocation calls of variable signal to noise ratios; these sequences are typical of those obtained from remote automated recording systems that are often used in large-scale ecological studies. We presented 45 recordings (1–4 calls) produced by known species of bats to ANNs and to 26 human participants with 1 month to 23 years of experience in acoustic identification of bats. Humans correctly classified 86% of recordings to genus and 56% to species; ANNs correctly identified 92% and 62%, respectively. There was no significant difference between the performance of ANNs and that of humans, but ANNs performed better than about 75% of humans. There was little relationship between the experience of the human participants and their classification rate. However, humans with <1 year of experience performed worse than others. Currently, identification of bat echolocation calls by humans is suitable for ecological research, after careful consideration of biases. However, improvements to ANNs and the data that they are trained on may in future increase their performance to beyond those demonstrated by humans.

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