Andy J. Musgrove

GB Non-native Species Information Portal: documenting the arrival of non-native species in Britain

Abstract Information on non-native species (NNS) is often scattered among a multitude of sources, such as regional and national databases, peer-reviewed and grey literature, unpublished research projects, institutional datasets and with taxonomic experts. Here we report on the development of a database designed for the collation of information in Britain. The project involved working with volunteer experts to populate a database of NNS (hereafter called “the species register”). Each species occupies a row within the database with information on aspects of the species’ biology such as environment (marine, freshwater, terrestrial etc.), functional type (predator, parasite etc.), habitats occupied in the invaded range (using EUNIS classification), invasion pathways, establishment status in Britain and impacts. The information is delivered through the Great Britain Non-Native Species Information Portal hosted by the Non-Native Species Secretariat. By the end of 2011 there were 1958 established NNS in Britain. There has been a dramatic increase over time in the rate of NNS arriving in Britain and those becoming established. The majority of established NNS are higher plants (1,376 species). Insects are the next most numerous group (344 species) followed by non-insect invertebrates (158 species), vertebrates (50 species), algae (24 species) and lower plants (6 species). Inventories of NNS are seen as an essential tool in the management of biological invasions. The use of such lists is diverse and far-reaching. However, the increasing number of new arrivals highlights both the dynamic nature of invasions and the importance of updating NNS inventories.

Estimates and trends of waterbird numbers wintering in Ireland, 1994/95 to 2003/04

Capsule There has been a decline in the numbers of waterbirds wintering in Ireland between 1994/95 and 2003/04, including a 5% decline in wildfowl and an 11% decline in waders. Aims To provide estimates of numbers and trends in relative abundance of selected waterbird species wintering on the island of Ireland. Methods Waterbird counts were undertaken at key wetland sites in Ireland each winter (September to March) between 1994/95 and 2003/04. For each species, estimates were calculated for two five-season periods (1994/95–1998/99 and 1999/2000–03/04), while trends in relative abundance were analysed over the entire ten-season period. Counts were modelled using a multiplicative log-linear index model, with site, year and month factors. Results National estimates of overwintering numbers were produced for 42 species of waterbirds, and used to produce all-Ireland 1% thresholds (which are used to evaluate the importance of wetland sites). In winter, large proportions of several populations occur in Ireland, particularly Whooper Swan Cygnus cygnus, Greater White-fronted Goose (Greenland race) Anser albifrons flavirostris, Brent Goose (Canadian Light-bellied race) Branta bernicla hrota and Black-tailed Godwit Limosa limosa islandica. Of the 39 species for which trends were measured, 18 showed annual declines in excess of 2%, while ten species had increased. Numbers of the remaining 11 species were relatively stable. For many species, the trends measured appear to be continuations of longer-term changes since the 1970s. Conclusion These most recent estimates of waterbird numbers have been improved compared with those previously generated, due to improved levels of coverage and better analytical methods. This study highlights that there have been significant changes in the numbers of waterbirds wintering in Ireland over the past 30 years. The fact that many of these trends parallel wider flyway-scale population trajectories implies that large-scale drivers (e.g. climate change) may be responsible. However, many of the observed declines are likely to be a consequence of increased economic development which has led to direct habitat loss to industrial and residential development.

Species traits explain variation in detectability of UK birds

Capsule Heterogeneous detectability amongst species may impact multi-species bird surveys and if not accounted for, may bias community level conclusions. Estimates of detectability were produced for 195 UK bird species, and detectability was significantly affected by bird size, diet and habitat specialization. Aims To estimate detectability and understand which species traits may impact detectability. Methods We estimated the detectability of 195 species of birds in the UK using distance sampling methods and examined the average detectability of genetically related groups. We tested the significance of species traits in describing variation in detectability, whilst controlling for phylogenetic relationships. Results Passeriformes had the lowest median detectability of 0.37 and Charadriiformes the highest median detectability of 0.65, of the seven largest orders considered. Species most associated with closed habitats such as woodland and urban areas had the lowest detectability. Smaller species had lower detectability than larger species. Conclusion Heterogeneity in species detectability could lead to biased conclusions, particularly when calculating multi-species indices such as species richness or diversity. Accounting for detectability will be most important in studies that cover a wide range of habitat types or a diverse spread of taxa.

Generating population estimates for common and widespread breeding birds in Ireland

Capsule Population estimates for 51 common breeding birds, totalling 62 million individuals, were estimated for Ireland. Aims To generate robust population estimates for common and widespread breeding birds across Ireland. Methods Densities were generated for common breeding birds using data from annual bird monitoring surveys using count data for all years between 2006 and 2010 inclusive. Bird atlas data were then used to (1) quantify the distribution of each species (10-km squares), and (2) generate an estimate of proportion occurrence of each species within each square. The total number of birds of each species was generated by multiplying proportion occupancy by the total area of the 10-km square and by the mean regional density generated from the bird monitoring data, and by summing the estimates of squares. Results Almost 62 million individuals of 51 common breeding birds were estimated. Wren Troglodytes troglodytes, with an estimate of more than 6 million individuals, contributed 10% of the total birds recorded. Swallow Hirundo rustica and Robin Erithacus rubecula were the next most numerous, at 5.8 and 5.4 million individuals. A total of 15 species were estimated at more than one million individuals each. Conclusion The estimates of detected individuals generated are based on best available information and analyses to date. Incorporating the bird atlas data permits vastly improved estimates by providing better informed distribution range across which the regional densities were extrapolated. However, estimation of densities and population sizes based on data from annual monitoring surveys alone is limited to species with widespread distributions because of the relatively low coverage and limited detectability of scarce species by this methodology.

Overcoming the challenges of public data archiving for citizen science biodiversity recording and monitoring schemes

Public data archiving (PDA) is widely advocated as a means of achieving open data standards, leading to improved data preservation, increased scientific reproducibility, and transparency, as well as additional data use. Public data archiving was primarily conceived to archive data from short‐term, single‐purpose scientific studies. It is now more widely applied, including to large‐scale citizen science biodiversity recording and monitoring schemes which combine the efforts of volunteers with professional scientists. This may affect the financial security of such schemes by reducing income from data and analytical services. Communication between scheme organizers and researchers may be disrupted, reducing scientific quality and impeding scheme development. It may also have an impact on the participation of some volunteers. Synthesis and applications. In response to the challenges of public data archiving for citizen science biodiversity recording and monitoring schemes, the archive function of scheme organizations should be better recognized by those promoting open data principles. Increased financial support from the public sector or from commercial or academic data users may offset financial risk. Those in favour of public data archiving should do more to facilitate communication between nonscheme users and the originating schemes, while a more flexible approach to data archiving may be required to address potential impacts on volunteer participation.