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The article discusses a study aimed at identifying based on geolocators the migration routes, breeding quarters and post-nuptial moulting areas of long-billed Purple Sandpipers that can be found during winter and spring in northern Scotland and western Ireland. Topics include the effect of the geolocators on the birds, the accuracy of geolocations, and the timing of migration. It concludes that bulk of the wintering Purple Sandpipers start from Canada, particularly in the Hudson Strait region.

Cherryslug, Caliroa cerasi, is an important pest of organic pear production in New Zealand. It is reported to have two generations per year and cause severe leaf damage, particularly through the feeding of second generation larvae in mid to late-summer. This insect has been little studied in Central Otago. Adult cherryslugs were monitored with sticky traps in a block of ‘Taylor's Gold’ pears in the summers of 1999–2001 and the catches were used to assist in timing the single application each season of a range of organically-acceptable insecticides in randomized block experiments which included untreated control trees. The insecticides were: 1999–2000, ryanodine, lime sulphur, kaolin in January, kaolin in February; 2000–01, pyrethrum +mineral oil, lime sulphur, neem extract, kaolin in January. Efficacy was assessed using pre- and post-treatment larval counts and leaf damage. The impact of pre-treatment larval density on post-treatment efficacy was investigated to determine a preliminary spray threshold, specifically for pyrethrum+mineral oil. The adult monitoring indicated that cherryslug is univoltine in Central Otago, with the first adults appearing at the end of December. All the insecticides tested significantly reduced damage from cherryslug larvae and, if registered, could be used by organic growers. In both seasons, kaolin application in January, which targeted the adult cherryslugs, was more effective than all the other products, which were applied in February against the larvae. On the other hand, kaolin applied in February 2000 resulted in greater cherryslug damage than occurred with the other insecticides applied at that time. Larval density had a significant effect on the efficacy of pyrethrum+mineral oil, particularly when >10 larvae could be counted per minute on the trees before treatment. The implications of this result and the comparative efficacy of the different treatments are discussed in relation to organic pear production in Otago. [ABSTRACT FROM PUBLISHER]

Oystershell scale, Diaspidiotus ostreaeformis, is a pest of fruit crops in Otago and Canterbury that is well controlled within orchards but becomes a problem at harvest due to invasion from external host trees. Its major pest status on export crops comes from its being indistinguishable on harvested fruit from the critical quarantine pest San Jose scale Diaspidiotus perniciosus. Oystershell scale has a wide host range which includes trees frequently used as orchard shelter. The distribution of oystershell scale in apples adjacent to an infested shelter belt was investigated in Otago in 1995-96. Apple infestation was >90% next to the shelter and declined linearly to <1% 64 m away. The slope of this linear regression was similar on four cultivars of apple but infestation increased substantially from early- to late-harvested cultivars. The phenology of oystershell scale on apples in 1998-2000 was found to precede that on a range of other hosts, which extended the period of risk of fruit infestation by crawlers from December to April each year. Experiments were conducted in 1999-2000 on control of oystershell scale on a range of infested shelter trees using a vertical boom sprayer. Sprays timed for control of adult males and females in spring provided only a short-term reduction of winged males in sticky traps and failed to reduce crawler production and dispersal as measured by sticky bands and traps on tree branches. On the other hand, sprays timed for control of crawlers in mid-summer were effective in greatly reducing catches of crawlers. The options for management of oystershell scale on alternative hosts, particularly shelter, are discussed in relation to phenology, crop invasion by crawlers, host resistance and spraying. [ABSTRACT FROM AUTHOR]

Woolly apple aphid (WAA), Eriosoma lanigerum (Hausmann), and its natural enemies were monitored from 1994 to 2000 on apples at Clyde, Central Otago, New Zealand during the transition from conventional fruit production (CFP), which used broad spectrum insecticides, to integrated fruit production (IFP), which was based on selective insecticides. Populations were compared in orchard blocks under three management regimes: CFP; transition to IFP; and a biological fruit production (BFP) programme which complied with BioGro® organic certification. WAA remained at very low levels in the CFP programme, because of insecticides, and in the BFP programme, primarily because of natural enemies. Transition to IFP was accompanied by a surge in WAA and a slow colonization by natural enemies which took at least four years to reduce the aphid population to acceptable levels. The principal natural enemy that achieved this was the parasitoid Aphelinus mali (Haldemann), assisted by predators whose contribution remained obscure, including the brown lacewing Micromus tasmaniae (Walker) and the European earwig Forficula auricularia L. A single annual application of lufenuron within the IFP programme was not detrimental to any of these natural enemies, although further research is needed to confirm its lack of impact on the lacewing. Lufenuron reduced arboreal predator diversity, as measured by the Shannon-Wiener index, and this was in part due to decline in the populations of the generalist predator Orius vicinus (Ribaut) and the coccinellid mite predator Stethorus bifidus Kapur. Pirimicarb was an effective selective aphicide for integration with the action of the natural enemies of WAA, but a substitute is required, as its use is no longer permitted on export crops. The implications of these findings for the management of WAA in IFP are discussed. [ABSTRACT FROM AUTHOR]

The article provides evidence that majority of Scottish- and Irish-wintering Purple sandpipers migrate to Arctic Canada to breed. Topics discussed include the trans-Atlantic migration of the birds in early winter, the median arrival date for all birds in Greenland, and the geo-locations of the birds prior to departure from northern Scotland and Ireland.

Recent studies have suggested that protected areas often fail to conserve target species. However, the efficacy of terrestrial protected areas is difficult to measure, especially for highly vagile species like migratory birds that may move between protected and unprotected areas throughout their lives. Here, we use a 30-y dataset of detailed demographic data from a migratory waterbird, the Whooper swan ( Cygnus cygnus ), to assess the value of nature reserves (NRs). We assess how demographic rates vary at sites with varying levels of protection and how they are influenced by movements between sites. Swans had a lower breeding probability when wintering inside NRs than outside but better survival for all age classes, generating a 30-fold higher annual growth rate within NRs. There was also a net movement of individuals from NRs to non-NRs. By combining these demographic rates and estimates of movement (into and out of NRs) into population projection models, we show that the NRs should help to double the population of swans wintering in the United Kingdom by 2030. These results highlight the major effect that spatial management can have on species conservation, even when the areas protected are relatively small and only used during short periods of the life cycle.

Environmental heterogeneity shapes the uneven distribution of resources available to foragers, and is ubiquitous in nature. Optimal foraging theory predicts that an animal's ability to exploit resource patches is key to foraging success. However, the potential fitness costs and benefits of foraging in a heterogeneous environment are difficult to measure empirically. Heterogeneity may provide higher-quality foraging opportunities, or alternatively could increase the cost of resource acquisition because of reduced patch density or increased competition. Here, we study the influence of physical environmental heterogeneity on behaviour and reproductive success of black-legged kittiwakes, Rissa tridactyla. From GPS tracking data at 15 colonies throughout their British and Irish range, we found that environments that were physically more heterogeneous were associated with longer trip duration, more time spent foraging while away from the colony, increased overlap of foraging areas between individuals and lower breeding success. These results suggest that there is greater competition between individuals for finite resources in more heterogeneous environments, which comes at a cost to reproduction. Resource hotspots are often considered beneficial, as individuals can learn to exploit them if sufficiently predictable. However, we demonstrate here that such fitness gains can be countered by greater competition in more heterogeneous environments.

In many animals, processes occurring in one season carry over to influence reproductive success and survival in future seasons. The strength of such carry-over effects is unlikely to be uniform across years, yet our understanding of the processes that are capable of modifying their strength remains limited. Here we show that female light-bellied Brent geese with higher body mass prior to spring migration successfully reared more offspring during breeding, but only in years where environmental conditions during breeding were favourable. In years of bad weather during breeding, all birds suffered reduced reproductive output irrespective of pre-migration mass. Our results suggest that the magnitude of reproductive benefits gained by maximising body stores to fuel breeding fluctuates markedly among years in concert with conditions during the breeding season, as does the degree to which carry-over effects are capable of driving variance in reproductive success among individuals. Therefore while carry-over effects have considerable power to drive fitness asymmetries among individuals, our ability to interpret these effects in terms of their implications for population dynamics is dependent on knowledge of fitness determinants occurring in subsequent seasons.

1. It has been known for some time that the consequences of 'decisions' made at one point in an animal's life may not always be borne immediately. For example, numerous studies have demonstrated the trade-off between current and future breeding success across multiple taxa. 2. It is becoming increasingly clear that such processes may also operate among seasons, such that the conditions experienced at one point in the annual cycle may have significant downstream impacts, or 'carry-over effects', and this is particularly evident among migratory species. We might therefore predict that certain combinations of reproductive and migratory strategy could lead to profound carry-over effects. However, the extent to which these phenomena might generate variation in fitness within a population is unclear. 3. Here, we investigate how winter habitat selection in a long-distance migrant, with extended parental care (the Light-bellied Brent goose) is influenced by parental status and how this has a counterintuitive effect on subsequent breeding success. 4. Dominant individuals and groups generally monopolize the best quality resources. In the case of geese, families are dominant; however, our findings highlight a hidden cost to raising a family. Stable isotope analysis demonstrates that later in the non-breeding season, adults with families utilize lower quality resources than non-breeders. This is probably caused by parents being constrained in habitat choice by the lower foraging efficiency of their juveniles. Consequently, parental adults end the winter in poorer condition than non-breeders. 5. We further demonstrate that parents in one year are less likely than expected to breed again in the next year and suggest that this is caused by conditions during the non-breeding period being carried over into the breeding season. In conclusion, we demonstrate previously hidden costs to raising a family, which are likely to be important in terms of life-history evolution.

1. Individual variability in prey preferences can have marked effects on many demographic parameters from individual survival and fecundity to the vital rates of entire populations. A population level response is ultimately determined by individual prey choices; however, the effect of individual dietary choice is often overlooked. 2. We determined prey choice by individual consumers, light-bellied Brent geese Branta bernicla, during the overwintering period. Two hundred and eighty-one individuals were sampled at distinct temporal points over two winters. Stable isotopic ratios of carbon and nitrogen for blood cells and blood plasma, from each sampled individual were measured. Isotopic ratios for potential prey items were also measured. 3. Delta15N and delta13C for blood samples were both significantly different between sample months. Generally we found a decrease in both isotopic ratios during the course of the winter. All potential prey items were also isotopically distinct. Multisource mixing models (isosource) were used to determine the range of possible contribution to the diet of individuals. 4. During early winter, diet consisted almost exclusively of sea grass Zostera spp. The level of Zostera spp. in the diet dropped until mid-winter, and was supplemented by the utilization of green algae Ulva lactuca, and Enteromorpha spp., and terrestrial grasses. Terrestrial grass comprised an increasing proportion of the diet in late winter, representing virtually the exclusive food source by April. 5. By examining intrapopulation variability in resource utilization we highlight a number of ecologically important factors not addressed by previous population level studies.