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To date, agri-environment schemes (AES) have had limited success in reversing biodiversity loss over greater spatial extents than fields and farms, and vary widely in their cost-effectiveness. Here, over nine years, we make use of the management initiative of a farmer in an upland livestock farming landscape in Scotland, undertaken wholly outside AES, to examine its effect on breeding densities of Northern Lapwing Vanellus vanellus . Management designed by the farmer involved planting a Brassica fodder crop for two consecutive years followed by reseeding with grass, with eight out of 17 fields at the farm undergoing this management since 1997. After controlling for other habitat parameters of importance, the density of breeding Lapwings was 52% higher in fields that had undergone fodder crop management than those that had not. Densities were highest in the first year after the fodder crop was planted, prior to reseeding with grass, but remained above levels in control fields for approximately seven years after the fodder crop was last planted. Very high Lapwing densities (modelled density = 1 pair ha -1 ) in the year after the fodder crop was planted likely result from the heterogeneous ground surface created by grazing of the crop providing an “attractive” nesting habitat. Continued high densities following reseeding with grass may partly be accounted for by philopatry, but the fact that they are field-specific also suggests that these fields continue to offer enhanced foraging conditions for several years. Fodder crop management was implemented at the study site to fatten lambs over winter and ultimately improve grass condition for grazing. This system is therefore based on active farming and benefits both the farmer and breeding Lapwings. As such, it may be possible to implement it more widely without the need for high agri-environment payments. More generally, it is an example of the land owner being actively involved in developing conservation solutions in partnership with environmental research, rather than being seen as a passive recipient of knowledge as has typically been the case with the design of AES. Such approaches need to be adopted more consistently in designing interventions for environmental outcomes on farmland, but may be of particular importance in the UK if the certainties of European Union AES are to come to an end. [ABSTRACT FROM AUTHOR]

Historically, the land-based threat to shorebird colonies on Phillip Island, Victoria, Australia, was fox predation. As a result, a fox eradication programme consisting of three phases: knock-down (i.e., 2006), clean-up (i.e., 2011), and post-eradication. In 2011 an effective knock-down was declared, signalling the beginning of the clean-up phase. The purpose of this research is to assess the recovery of six resident shorebird species on Phillip Island following fox removal. The statistical methodologies used are novel for assessing bird species population recovery following a successful predator eradication program. We used citizen science data from 2003 to 2017, extracted from the Atlas of Living Australia. The first analysis method used INLA modelling, which relied on a Negative Binomial distribution for bird counts to look for upward trends in shorebird populations during the fox eradication operation. The second method use changepoint analysis techniques to see whether successive phases of the eradication process were associated with changes in bird population numbers. Four of the six shorebird species investigated responded positively to reduced fox populations over the 15-year study, and all changepoint approaches consistently recognised the start of the clean-up phase, with less consistency identifying the start of the knock-down phase. Since 2006, the INLA models indicate a significant increase in the upward trend of shorebird populations for three of the six shorebird species investigated. Agreement across the four changepoint techniques indicates that changes in bird numbers were associated with the date of the eradication program's clean-up phase for all of these shorebird species. These results demonstrate some promise for these methods to monitor native species recovery during eradication programs. [ABSTRACT FROM AUTHOR]

Highlights: [•] We develop a Bayesian network to predict piping plover nest presence. [•] Nest predictions were linked to physical nesting habitat features. [•] Wide environmental ranges produced the best model performance. [•] All models were better at predicting nest presence than nest absence. [Copyright &y& Elsevier]

Highlights: [•] Remotely-sensed breeding habitat for a federally-listed species. [•] Habitat varied markedly among years (1986–2009) ranging from 9 to 5195ha. [•] Predicted habitat (ha) with water levels, modeled revegetation rate, and topography. [•] Predictive model could inform conservation through what-if scenarios. [•] Approach adaptable to other systems to improve habitat and population estimation. [Copyright &y& Elsevier]

Abstract: Sum-PBDEs concentrations in shorebirds and Anatidae ducks muscles from Chongming Dongtan National Nature Reserve ranged from 21–324 to 14–159ngg−1 lw, respectively. PBDEs were detected in muscles of all the studied species. Compared with flyways around the world, migratory waterbirds on the East Asian–Australasian flyway exhibited lower PBDEs burdens than those reported on Black Sea-Mediterranean flyway in Europe and Pacific, Atlantic, Mississippi flyway in North America. Residential Eurasian tree sparrow samples indicated few PBDE products were used in Chongming Island developed in the idea of world famous eco-island. There was no significant difference in PBDEs concentrations between shorebirds and ducks. However, PBDEs composition varied between them. BDE 209 (29–44%) contributed to sum-PBDEs more than BDE 47 (17–19%) in muscles of ducks, while BDE 47 was the predominant congener in shorebirds contributing 32–48%. Stable nitrogen and carbon isotopes and stomach content analysis indicated shorebirds and ducks had the same dietary composition, but showed different preference to bivalves, gastropods and crustaceans for shorebirds and aquatic plant material for ducks. Migratory species had inherent migratory routes and thus had exposure to PBDEs during their stay in breeding grounds, stopover sites and wintering grounds with high use of different commercial PBDE mixtures. Higher percentage of BDE 209 in ducks than shorebirds suggested that breeding ranges and wintering grounds of ducks comprise wetlands in inland and coastal China and Korea where decaBDEs pollution was serious in Asian-Pacific region. Our findings reveal the influence of migratory behavior on PBDEs distribution in migratory waterbirds. [Copyright &y& Elsevier]

Abstract: With a worldwide increase in energy needs, many countries are increasing their development of renewable sources, such as wind and solar. We examined possible risk to a migrating and wintering shorebird (red knots Calidris canutus rufa) along the Atlantic Coast of the United States by developing a conceptual model of assessment endpoints, stressors, exposure, and effects characterization, and testing the applicability of knots fitted with geolocators to provide data for salient aspects of exposure and risk for coastal and offshore development. Birds were fitted with geolocators in Delaware Bay (New Jersey) and Monomoy Refuge (Massachusetts) in 2009, and recaptured at the same locations in 2010. The knots recaptured in Delaware Bay were long-distance migrants that spent less time along the Atlantic Coast (<7%, N =3), while the knots recaptured in Monomoy spent over half of the year migrating, at stopovers, and wintering along the Atlantic Coast (>60%, N =6 with one-year cycle). The continuous record of geolocators provides useful data for a risk evaluation about: (1) high use areas for this shorebird (2) migration, staging and wintering areas, (3) possible foraging times while at stopovers, (4) synchrony of arrival and departure times, (5) weight or condition following a yearly cycle, and (6) direction of movements over the Atlantic Outer Continental Shelf (AOCS), a potential risk consideration with respect to offshore wind development. All knots crossed the AOCS at least twice during long-distance flights, and more often on shorter flights. The knots captured at Monomoy spent over 60% of their cycle while migrating, at stopovers, and while wintering along the Atlantic coast, suggesting the importance of this region to conservation of knots. [Copyright &y& Elsevier]

Abstract: Trace element concentrations (Ag, As, Cd, Co, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Se, Zn) were investigated in the liver, kidneys, muscle and feathers of 31 black-tailed godwits (Limosa limosa) accidentally killed during catches by mist net in the Pertuis Charentais, Atlantic coast of France. Analyses of carbon and nitrogen stable isotope ratios were carried out in liver, muscle and feathers in order to elucidate dietary patterns and to determine whether differences in diet explained the variation in elemental uptake. This study also aimed to have a preliminary assessment of sub-lethal effects triggered by trace elements through the investigation of gene expressions by quantitative real-time PCR, antioxidant enzyme activities (catalase, superoxide dismutase, glutathione peroxidase), and metallothionein (MT) levels. The results showed that Cr and Ni concentrations in tissues of adults were lower than in juveniles in part because adults may have eliminated these trace elements through moulting. Except for Cd and Ni, trace element concentrations were negatively correlated to the body mass of godwits. Ag, As, Hg and Se concentrations were positively linked with the trophic position of birds. The diet could be considered as a fundamental route of exposure for these elements demonstrating therefore the qualitative linkage between dietary habits of godwits and their contaminant concentrations. Our results strongly suggest that even though trace element concentrations were mostly below toxicity threshold level, the elevated concentrations of As, Ag, Cd, Cu, Fe and Se may however trigger sub-lethal effects. Trace elements appear to enhance expression of genes involved in oxidative stress defence, which indicates the production of reactive oxygen species. Moreover, birds with the highest concentrations appeared to have an increased mitochondrial metabolism suggesting that the fight against trace element toxicity requires additional energetic needs notably to produce detoxification mechanisms such as metallothioneins. [Copyright &y& Elsevier]

Abstract: The wing louse genus Lunaceps, is the most speciose chewing louse (Phthiraptera) genus inhabiting sandpipers (Charadriiformes: Calidrinae) and is known from almost all sandpiper species. The hosts follow specific flyways from the Arctic breeding grounds to wintering locations in the southern hemisphere, and often form large mixed-species flocks during migration and wintering. We estimated a phylogeny of Lunaceps based on three mitochondrial loci, supporting monophyly of the genus but revealing extensive paraphyly at the species level. We also evaluated the relative importance of flyway differentiation (same host species having different lice along different flyways) and flyway homogenisation (different host species having the same lice along the same flyway). We found that while the lice of smaller sandpipers and stints show some evidence of flyway homogenisation, those of larger sandpipers do not. No investigated host species migrating along more than one flyway showed any evidence of flyway differentiation. The host–parasite associations within Lunaceps are in no case monophyletic, rejecting strict cospeciation. [Copyright &y& Elsevier]

Abstract: Migratory routes of gulls, terns, and shorebirds (Charadriiformes) are known to cross hemispheric boundaries and intersect with outbreak areas of highly pathogenic avian influenza (HPAI). Prior assessments of low pathogenic avian influenza (LPAI) among species of this taxonomic order found some evidence for trans-hemispheric movement of virus genes. To specifically clarify the role of shorebird species in the trans-hemispheric movement of influenza viruses, assess the temporal variation of Eurasian lineages observed previously among North American shorebirds, and evaluate the necessity for continued sampling of these birds for HPAI in North America, we conducted a phylogenetic analysis of >700 contemporary sequences isolated between 2000 and 2008. Evidence for trans-hemispheric reassortment among North American shorebird LPAI gene segments was lower (0.88%) than previous assessments and occurred only among eastern North American isolates. Furthermore, half of the reassortment events occurred in just two isolates. Unique phylogenetic placement of these samples suggests secondary infection and or involvement of other migratory species, such as gulls. Eurasian lineages observed in North American shorebirds before 2000 were not detected among contemporary samples, suggesting temporal variation of LPAI lineages. Results suggest that additional bird migration ecology and virus phylogenetics research is needed to determine the exact mechanisms by which shorebirds in eastern North America become infected with LPAI that contain Eurasian lineage genes. Because of the low prevalence of avian influenza in non-eastern North America sites, thousands more shorebirds will need to be sampled to sufficiently examine genetic diversity and trans-hemispheric exchange of LPAI viruses in these areas. Alternatively, other avian taxa with higher virus prevalence could serve as surrogates to shorebirds for optimizing regional surveillance programs for HPAI through the LPAI phylogenetic approach. [Copyright &y& Elsevier]

Effective conservation for listed migratory species requires an understanding of how drivers of population decline vary spatially and temporally, as well as knowledge of range-wide connectivity between breeding and nonbreeding areas. Environmental conditions distant from breeding areas can have lasting effects on the demography of migratory species, yet these consequences are often the least understood. Our objectives were to 1) evaluate associations between survival and extreme environmental disturbances at nonbreeding areas, including hurricanes, harmful algal blooms, and oil spills, and 2) estimate migratory connectivity between breeding and nonbreeding areas of midcontinental piping plovers (Charadrius melodus). We used capture and resighting data from 5067 individuals collected between 2002 and 2019 from breeding areas across the midcontinent, and nonbreeding areas throughout the Gulf of Mexico and southern Atlantic coasts of North America. We developed a hidden Markov multistate model to estimate seasonal survival and account for unobservable geographic locations. Hurricanes and harmful algal blooms were negatively associated with nonbreeding season survival, but we did not detect a similarly negative relationship with oil spills. Our results indicated that individuals from separate breeding areas mixed across nonbreeding areas with low migratory connectivity. Mixing among individuals in the nonbreeding season may provide a buffering effect against impacts of extreme events on any one breeding region. Our results suggest that understanding migratory connectivity and linking seasonal threats to population dynamics can better inform conservation strategies for migratory shorebirds. [ABSTRACT FROM AUTHOR]

Since 1992, efforts to recover the US federally endangered Great Lakes piping plover (Charadrius melodus) have included population supplementation with captive-reared young raised from abandoned eggs. Using banding data collected 1993–2008 and Cormack–Jolly–Seber models in program MARK we estimated resighting rates (ρ) and apparent survival (Φ) of first-year (1) and after-first-year (2+) plovers. Reproductive success was measured by estimating mean number of eggs laid, chicks hatched and chicks fledged per wild-reared or captive-reared parent, and these values were compared with a permutation test. The best-supported mark-resighting model indicated wild-reared plovers had higher Φ 1 and Φ 2+ than captive-reared plovers. Breeding propensity influenced detection of wild plovers, whereas unique band combinations facilitated detection of yearling captive-reared plovers. Captive-reared (n =10) and wild-reared (n =57) plovers laid similar numbers of eggs, but wild-reared plovers hatched 36% more chicks and fledged 56% more young. Reproductive values derived from matrix models suggest captive-reared piping plovers are less fit than similarly aged wild-reared birds upon release and demonstrate reduced fitness in subsequent years. The Great Lakes captive-rearing effort has successfully produced a minimum of 10 breeding adults from 192 eggs that otherwise would have had no reproductive value; these captive-reared individuals now constitute up to 3% of the total population. Small scale salvage and captive-rearing of abandoned eggs should be considered as a technique to supplement existing recovery efforts in highly imperiled populations. [Copyright &y& Elsevier]

Abstract: Waders leave nests and conduct distractive displays when approached by people. The time taken for waders to return to nests depends on numerous factors that affect the costs and benefits of incubation and anti-predator behavior. Understanding this trade-off may help assess the reproductive consequences of different nest return times and identify variables to consider in breeding disturbance studies. We subjected 73 Malaysian plover (Charadrius peronii) nests to standardized human disturbances and an analysis of covariance was used to determine how weather, time of day, embryonic age, weeks into breeding season and nest attendance (proportion of time adults incubated nests) influence nest return times. Egg temperatures were estimated using a regression model that predicted the temperature inside unshaded eggs from air temperature, cloud cover and time of day (r 2 =0.88). We assessed the relationship between nest return times and hatch success. Plovers returned to nests faster at higher modeled egg temperature (P =0.010), in the morning (P =0.003), if they had younger clutches (P =0.038), and if they had high nest attendance prior to the disturbance (P =0.015). Pairs that returned to nests faster had lower hatch success (P =0.021). This may be because pairs that spend more time distracting humans may also do so for predators. These results suggest that short nest return times may not indicate low fitness costs of disturbance. The thermal and predation environment in addition to nest return times should be taken into account when assessing the deleterious effects of human disturbance. [Copyright &y& Elsevier]

Abstract: The extent of a shorebird’s response to a human disturbance depends on the associated energetic or predation risk costs. These costs are influenced by a suite of environmental variables, operating at several temporal and spatial scales. Here, I measured prey availability, distance to forest cover, cloud cover, and wind speed, in addition to human and shorebird densities to examine how human presence affected habitat choice, relative to these environmental variables, at Pachena Beach, British Columbia. In a standardised experiment, I also approached feeding flocks to determine if environmental factors influenced the time take for shorebirds to resume feeding. Binary logistic models suggested that people did not displace shorebirds. Instead, shorebirds were preferentially selecting areas further from forest cover that may have had lower predation risk. The time taken for shorebirds to resume feeding after a human disturbance was greater in the morning and in areas of low prey availability. This suggests that shorebirds respond more to a disturbance when the foraging cost is lower indicating that behavioural responses may not necessarily reflect the potential fitness costs of human disturbance. [Copyright &y& Elsevier]

We examined the efficacy of habitat creation for shorebirds on reclaimed land in Osaka Port. The Wild Bird Park was laid out on a reclaimed land in Osaka Port in 1983. A modern history of the area as a habitat for shorebirds can be divided into four stages. First, many shorebirds visited the tidal flat of 30 ha that emerged on the south part of the Sakishima, which had been reclaimed from the sea in 1941, but was abandoned between 1950 and 1958 [Notes on Osaka Bay Waders. Private Publishing (in Japanese with English abstract)]. Second, the tidal flat disappeared because of the start of the reclamation of the north part of Sakishima in 1958, and a salt marsh of 85 ha emerged in the north part between 1974 and 1982. Third, the salt marsh disappeared due to the construction and the Wild Bird Park was opened on a part of the salt marsh in 1983. The park had a planted area of 6.5 ha and a sandy area of 12.8 ha, which included two ponds and a lagoon. Fourth, one of the ponds was restored to a tidal flat in 1995 after consultation among the manager, NPO, and scientist as a result of the monitoring. The area of tidal flat increased from 0.2 to 2.6 ha, and the number of shorebirds increased from 205 (the average of 1991–1995) to 1042 (1996). The abundance and species richness of shorebirds is equivalent to those at the first stage (1950s). The species composition of benthic animals had also changed; the dominant group was Chironomid larvae during the second and third stages and Polychaetes during the fourth stage, and the species richness was greatest at the fourth stage. However, the tidal flat of the park had fewer brachyurans and mollusks than natural tidal flats in Japan. This might result in a lower abundance of large sandpipers at the fourth stage compared with that at the first and second stages. [Copyright &y& Elsevier]

The effects of flooding harvested rice fields on waterbird communities were studied during winter. Variation in the number of waterbird species, overall densities of all waterbirds, wading birds, waterfowl, and shorebirds, and a measure of conservation value that weighted species according to their relative abundance and population trends were examined. Each variable was tested for differences among: (a) flooded and unflooded fields; (b) flooded fields that received different rice straw manipulations; and (c) fields with different water depths. Flooded fields were used by waterbirds more than unflooded fields according to most criteria, although wading bird densities did not differ between flooded and unflooded fields. In terms of conservation value, flooded fields contributed considerably more to waterbird conservation than unflooded fields. The number of waterbird species, total waterbird density, and the density of wading birds differed significantly among straw management treatments, though in different ways. Water depth significantly affected all measures, but in all cases most of the variation went unexplained. Bird densities were explained best by asymptotic relationships, with shorebird densities greatest in shallow water and waterfowl and wading bird densities greatest in deeper conditions. Waterbird richness and conservation value both were greatest at depths of 10–15 cm. Intentionally flooding fields during winter significantly affected numerous aspects of the waterbird community. The method of flooding also influenced the waterbird community, although these effects often were small. [Copyright &y& Elsevier]

Many countries, including China, have increased new areas of mangrove plantations to reverse the decline in mangrove ecosystem functions. However, this has led to the intrusion of mangroves into many tidal flat areas, which are important habitats for shorebirds. A reduction in the available tidal flat areas will reduce the diversity of shorebirds, therefore bringing mangrove conservation into conflict with shorebird conservation. In fact, a certain area of mangroves is an indispensable element of shorebird habitat. Therefore, this study proposes the maintenance of a ratio between the area of tidal flats and the area of mangroves within a mangrove ecosystem which is optimal for both mangrove conservation and shorebird conservation. This study recorded data for shorebird distribution, areas of mangrove and tidal flats, and other relevant data for Guangdong Province, China. The ratios of tidal flat areas to mangrove areas within mangrove ecosystems were established and a mathematical model was applied to establish the relationship between shorebird diversity and abundance and the ratios of tidal flat areas to mangrove areas. The results showed that: (1) there was no significant correlation between mangrove area and shorebird richness (r = 0.176, p = 0.230)and abundance(r = 0.104,p = 0.481), whereas there was no significant correlation between tidal flat area and shorebird richness(r = 0.153, p = 0.299)and abundance(r = −0.063,p = 0.670); (2) the relationship between the ratios of tidal flats area to mangrove area [ x ] and shorebird richness [ f(x) ] and abundance [ g(x) ] satisfied the cubic function equation f(x) = 0.106 x 3 − 2.147 x 2 + 11.269 x (0.0265≤x ≤ 13.8100) (R2 = 0.714, P = 0.000), g (x) = 0.008 x 3 − 0.189 x 2 + 1.124 x (0.0265≤ x ≤ 13.8100) (R2 = 0.713, P = 0.000) ; (3) the appropriate value of x is 3.5662or 3.9785, and maintaining this ratio can reduce the conflict between mangrove conservation and shorebird conservation and promote the sustainable development of the mangrove ecosystem. This information can contribute to the sustainable development of mangrove planting management strategies at various scales and will be invaluable in assessing the effectiveness of existing mangrove management approaches. [ABSTRACT FROM AUTHOR]

Most birds incubate their eggs, which requires time and energy at the expense of other activities. Birds generally have two incubation strategies: biparental where both mates cooperate in incubating eggs, and uniparental where a single parent incubates. In harsh and unpredictable environments, incubation is challenging due to high energetic demands and variable resource availability. We studied the relationships between the incubation behaviour of sandpipers (genus Calidris) and two environmental variables: temperature and a proxy of primary productivity (i.e. NDVI). We investigated how these relationships vary between incubation strategies and across species among strategies. We also studied how the relationship between current temperature and incubation behaviour varies with previous day's temperature. We monitored the incubation behaviour of nine sandpiper species using thermologgers at 15 arctic sites between 2016 and 2019. We also used thermologgers to record the ground surface temperature at conspecific nest sites and extracted NDVI values from a remote sensing product. We found no relationship between either environmental variables and biparental incubation behaviour. Conversely, as ground-surface temperature increased, uniparental species decreased total duration of recesses (TDR) and mean duration of recesses (MDR), but increased number of recesses (NR). Moreover, small species showed stronger relationships with ground-surface temperature than large species. When all uniparental species were combined, an increase in NDVI was correlated with higher mean duration, total duration and number of recesses, but relationships varied widely across species. Finally, some uniparental species showed a lag effect with a higher nest attentiveness after a warm day while more recesses occurred after a cold day than was predicted based on current temperatures. We demonstrate the complex interplay between shorebird incubation strategies, incubation behaviour, and environmental conditions. Understanding how species respond to changes in their environment during incubation helps predict their future reproductive success. Unlabelled Image • We used ground-surface temperature and a primary productivity index to describe environmental conditions. • Most biparental species showed no relationship between incubation behaviour and environmental conditions. • Uniparental species showed a higher attentiveness, shorter and more frequent recesses in warm than in cold conditions. • Relationships found between uniparental species' incubation behaviour and temperature vary with primary productivity. • We found lag effects of past temperature, supporting the hypothesis that some species use their reserves during cold days. [ABSTRACT FROM AUTHOR]

• The loss of fallow fields could have led to the decline in farmland biodiversity. • We focused on the Greater Painted Snipe found in Asian rice paddies. • We conducted replicated playback surveys during the breeding season. • Wet fallow field loss was associated with decline in Greater Painted Snipe density. • We highlight the importance of fallow fields for farmland bird populations. Fallow fields provide suitable habitats for many farmland species in agricultural landscapes. Although the loss of fallow fields in the last few decades may be one of the major causes of the decline in farmland biodiversity, quantitative studies investigating the spatial and temporal associations between fallow fields and abundance of rice paddy organisms are few. This study focused on the Greater Painted Snipe (Rostratula benghalensis), a widespread wetland bird species in Asian rice paddies. We conducted replicated playback surveys in three regions of central Japan during the breeding seasons of 1997, 2006, 2007, 2018, and 2019. N -mixture models and model-selection approaches revealed positive associations between the immigration rate of Greater Painted Snipes and the area of wet fallow fields in 1997, when the species was still relatively common. Both observed and estimated densities showed (1) a severe decline in the population of Greater Painted Snipes in the Tsuchiura and Kasumigaura regions over a recent 22-year period in accordance with the reduction of fallow fields and (2) persistence of both wet fallow fields and Greater Painted Snipes in the Abiko region in 2018 and 2019. These results indicate that the loss of wet fallow fields since the late 1990s was associated with the decline of the Greater Panted Snipe population in Japanese agricultural landscapes. Our study highlights the potential importance of fallow fields for population trends of farmland birds and the necessity for their maintenance through, for example, agri-environmental schemes, in rice-producing countries. [ABSTRACT FROM AUTHOR]

Beach-nesting shorebirds are declining due, in part, to human disturbance in nesting areas. Sign-posts are installed around nesting areas to protect nests from people, but they may serve as perches and attract avian predators. From March–August 2018, we used passive infrared game cameras to monitor perching activity on 15 variations of sign-post designs on 2 barrier islands in North Carolina. We observed 110 independent perching events dominated (70%) by common (Quiscalus quiscula) and boat-tailed grackles (Quiscalus major) and laughing gulls (25%; Leucophaeus atricilla). We compared how the number of days perching occurred was associated with sign shape, material, sign-construction (sign x shape), position on post, and presence/absence of a nail on top of the post. Position of the sign on the post had the strongest effect on the number of days perching events occurred (χ2 = 18.62 df = 2 P < 0.001). Signs positioned flush with the top of the post were most frequently perched on (10% of perching days), followed by signs positioned lower (5%) and higher (2%) than the post top. The frequency of avian predators perching on triangular signs (8%) and rectangular signs (5%) did not differ (X2 = 2.89 df = 1 P = 0.11). While sign material (metal: 12%; laminated cardboard: 11%; plastic: 13%) did not affect the probability of perching (χ2 = 1.06 df = 2 P = 0.58), triangular plastic signs (11%) had more (χ2 = 6.011 df = 2 P = 0.05) perching activity than rectangle-metal (6%) and rectangle-laminated signs (6%). Presence (3%) or absence (4%) of a nail on top of posts did not affect the number of days perching occurred on a sign-post (χ2 = 0.59 df = 1 P = 0.52). We recommend managers position signs high on the post to reduce occurrences of predatory perching. If a choice of sign shape and material is available, rectangular metal or laminated cardboard signs may also reduce perching activity. Image 1 • Design variables: sign shape, material, sign-construction, position on post, nails. • 110 independent perching events dominated by 3 species. • Position of sign on post had strongest effect on perching activity. • Rectangular metal or laminated cardboard signs may also reduce perching activity. [ABSTRACT FROM AUTHOR]

Land-claim and human disturbance are major threats to shorebird population declines along the East Asian–Australasian Flyway. When existing tidal flats undergo greater anthropogenic disturbance from intensive urbanization, newly-formed tidal flats may provide alternative habitats for shorebirds. Knowledge of the key habitat factor influencing shorebirds communities is essential for tidal flat restoration and management, especially on intensively urbanized coasts. We compared the differences between old and newly-formed tidal flats in terms of habitat characteristics and shorebird communities, analyzed the influence of habitat metrics on shorebird species abundance and feeding strategies in Macao, China, from 2006 to 2009. Habitat characteristics and shorebird communities were significantly different between old and newly-formed tidal flats which represented different urbanization level. The greatest difference of shorebird communities between two tideland types occurred in winter. Artificial shoreline rather than high rise buildings had direct and negative impact on shorebird communities. The habitat factors relieved shorebirds from surrounding urbanized environment were vegetation coverage within tidal flat and adjacent grassland areas. Under the pressure of rapid urbanization, the newly-formed tidal flat, which had more natural boundaries, adequate vegetation coverage and extensive adjacent undisturbed grassland, provided more suitable habitat than old tidal flats for shorebirds in Macao. Conservation efforts for shorebirds should primary focus on maintaining the extent of current tidal flats, with emphasized management on reducing anthropogenic disturbance around tidal flats. Image 1 • Habitat characteristics affecting shorebird distributions were identified. • Newly formed wetlands supported more diversified and abundant shorebirds. • Vegetation and grassland may be the shelter from human disturbance, while artificial shoreline has direct negative impact. • Divergence in seasons and migratory status were responsible for habitat selection. [ABSTRACT FROM AUTHOR]

Colonization of a recreated area of intertidal land by marine invertebrates and their bird predators was studied from April 1993 to August 1997. The most important food of large shorebirds, the ragworm Nereis diversicolor, did not reappear until late summer 1995 and did not become abundant until the following autumn. Annual attempts at colonization by the crustacean Corophium volutator, the main food of several small shorebird species, failed until summer 1996 when animals survived through the subsequent winter for the first time. Colonization by the mud-snail Hydrobia ulvae took place a year after flooding of the site, but densities in 1997 were still well below those found elsewhere on the adjacent estuary. The delay in successful colonization by Nereis and Corophium may be attributable in part to the compaction of the intertidal muds caused by the earthmoving equipment used to contour the site. The slow increase in Hydrobia density may be a consequence of low organic content of the mud. Bird use is concentrated chiefly during the hours when the adjacent estuarine mudflats (with unrestricted tidal flow) are covered by the tide, since the new site thenprovides a supplementary feeding area. Peak daytime usage occurs during the migratory passage periods when birds need to feed for longer periods than usual, in order to refuel for their migrations; high usage is also anticipated in cold winters. On this evidence, creation of intertidal areas in mitigation for any lost nearby to industrial orother development should take place at least three years before the losses, in order to make the new areas profitable for feeding waterfowl. [ABSTRACT FROM AUTHOR]