The Breeding Ecology of the Lapwing at Seal Sands, Teesside:: with reference to Food, the Environment and three Neighbouring Species.

The breeding success of the Lapwing at the ICI Brinefields, Teesside, was studied in comparison to three other species - the Ringed Plover, Redshank and Skylark. Environmental data was recorded and pitfall traps were set up to study the available food. Clutch losses were low in comparison with other studies for all four species, there being no significant difference between species. Predation accounted for most losses. Growth rates of chicks varied widely between species. Lapwing chicks grew slowly - at a rate significantly lower than a study in Teesdale this year. Ringed Plover chicks grew slowly too, though at a slightly faster and more steady rate. The growth of the Skylark chicks was quick and unrestricted. Differences in growth rates were probably attributable to differences in the availability of food to the species. Many Lapwing chicks grew up by channel edges where their food was, although relatively easy to find, not very abundant. Dry weather and saline water may have caused the chicks to dehydrate. Brooding of Lapwing chicks was shown to decrease with age and be extremely rare in direct sunlight. Lapwing chick mortality was very high - there being a calculated zero survival rate. Ringed Plovers faired much better, (54% of chicks fledging); Skylark chicks had even better survival rates. Predation was not thought to be the major cause of the Lapwing's low survival rate - partially because of the high survival of other species and partially because of the low clutch predation rate. The mortality of Lapwing chicks was positively correlated to their growth rates and this suggested that poor growth and the problems of dehydration were probably the major causes of mortality

Population overlap and habitat segregation in wintering Black-tailed Godwits Limosa limosa

Distinct breeding populations of migratory species may overlap both spatially and temporally, but differ in patterns of habitat use. This has important implications for population monitoring and conservation. To quantify the extent to which two distinct breeding populations of a migratory shorebird, the Black-tailed Godwit Limosa limosa, overlap spatially, temporally and in their use of different habitats during winter. We use mid-winter counts between 1990 and 2001 to identify the most important sites in Iberia for Black-tailed Godwits. Monthly surveys of estuarine mudflats and rice-fields at one major site, the Tejo estuary in Portugal in 2005-2007, together with detailed tracking of colour-ringed individuals, are used to explore patterns of habitat use and segregation of the Icelandic subspecies L. l. islandica and the nominate continental subspecies L. l. limosa. In the period 1990-2001, over 66 000 Black-tailed Godwits were counted on average in Iberia during mid-winter (January), of which 80% occurred at just four sites: Tejo and Sado lower basins in Portugal, and Coto Dontildeana and Ebro Delta in Spain. Icelandic Black-tailed Godwits are present throughout the winter and forage primarily in estuarine habitats. Continental Black-tailed Godwits are present from December to March and primarily use rice-fields. Iberia supports about 30% of the Icelandic population in winter and most of the continental population during spring passage. While the Icelandic population is currently increasing, the continental population is declining rapidly. Although the estuarine habitats used by Icelandic godwits are largely protected as Natura 2000 sites, the habitat segregation means that conservation actions for the decreasing numbers of continental godwits should focus on protection of rice-fields and re-establishment of freshwater wetlands

Effects of reductions in organic and nutrient loading on bird populations in estuaries and coastal waters of England and Wales Interim report March 2001

Includes bibliographical referencesAvailable from British Library Document Supply Centre- DSC:2354. 730(no 255) / BLDSC - British Library Document Supply CentreSIGLEGBUnited Kingdo

A review of the status and population trends of ground-nesting birds vulnerable to mink predation on Harris and Lewis

SIGLEAvailable from British Library Document Supply Centre- DSC:2354.73( no 230) / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Winter gull roosts in the United Kindgom in January 1993 with recommendations for future surveys of wintering gulls

Includes bibliographical referencesAvailable from British Library Document Supply Centre- DSC:2354. 730(no 277) / BLDSC - British Library Document Supply CentreSIGLEGBUnited Kingdo

Sample Size Required to Characterize Area Use of Tracked Seabirds

Conflicts in resource use between humans and wildlife populations are increasingly determined through quantitative approaches. To better understand interactions between birds and human activities in the marine environment, telemetry is routinely used to characterize the area use of species, but evaluations are often based on a small number of individuals taken as representative of a local population studied. Furthermore, the relative importance of the number of animals required and for what duration they should be tracked has received little attention. We examined the central-place foraging movements of 24 lesser black-backed gulls (Larus fuscus) from a protected population from 1 March to 31 August during 2010–2013. Using bootstrapping and non-linear modeling, we investigated whether sample sizes were sufficient to characterize offshore area use by considering the cumulative area use for an increasing number of birds and duration of tracking. Box-and-whisker analysis suggested a minimum of 13 birds and a precautionary upper maximum of 41 birds were needed to describe 95% of the estimated area use of the population (defined by 100% occupancy). Tracking fewer birds for longer was more important than tracking more birds for less time. A period of 145 days was required to characterize area use for 13–41 birds; however, offshore areas were used primarily after May, meaning that a 97-day tracking period from May onwards was also representative. Predicted and observed areas were strongly correlated, and the predicted area of 15 birds for 151 days was 91% of the total estimated for the population. These findings suggest that the data were suitable for determining interaction with offshore developments, and were characteristic of the population. This study has revealed the power of a long-term tracking dataset, and has uncovered further complexities surrounding study design and analysis that may shape conclusions drawn. The method and considerations raised have wider applicability for other datasets where human-wildlife resource use conflicts need to be assessed