scholarly journals Migrant semipalmated sandpipers (Calidris pusilla) have over four decades steadily shifted towards safer stopover locations

2019 ◽  
Author(s):  
David D. Hope ◽  
David B. Lank ◽  
Paul A. Smith ◽  
Julie Paquet ◽  
Ronald C. Ydenberg
Keyword(s):  
Intertidal Area ◽  
Data Set ◽  
Stopover Site ◽  
Semipalmated Sandpiper ◽  
Peregrine Falcons ◽  
Distribution Index ◽  
Migrant Birds ◽  
Calidris Pusilla ◽  
Index Value ◽  
Semipalmated Sandpipers

ABSTRACTPeregrine falcons (Falco peregrinus) have undergone a steady hemisphere-wide recovery since the ban on DDT in 1973, resulting in an ongoing increase in the level of danger posed for migrant birds, such as Arctic-breeding sandpipers. We anticipate that in response migrant semipalmated sandpipers (Calidris pusilla) have adjusted migratory behaviour, including a shift in stopover site usage towards locations offering greater safety from falcon predation.We assessed semipalmated sandpiper stopover usage within the Atlantic Canada Shorebird Survey dataset. Based on 3,030 surveys (totalling ∼32M birds) made during southward migration, 1974 - 2017, at 198 stopover locations, we assessed the spatial distribution of site usage in each year (with a ‘priority matching distribution’ index, PMD) in relation to the size (intertidal area) and safety (proportion of a site’s intertidal area further than 150m of the shoreline) of each location. The PMD index value is > 1 when usage is concentrated at dangerous locations, 1.0 when usage matches location size, and < 1 when usage is concentrated at safer locations.A large majority of migrants were found at the safest sites in all years, however our analysis of the PMD demonstrated that the fraction using safer sites increased over time. In 1974, 80% of birds were found at the safest 20% of the sites, while in 2017, this had increased to 97%. A sensitivity analysis shows that the shift was made specifically towards safer (and not just larger) sites. The shift as measured by a PMD index decline cannot be accounted for by possible biases inherent in the data set. We conclude that the data support the prediction that increasing predator danger has induced a shift by southbound migrant semipalmated sandpipers to safer sites.

Variation in diet of Semipalmated Sandpipers (Calidris pusilla) during stopover in the upper Bay of Fundy, Canada

2012 ◽  
Vol 90 (9) ◽  
pp. 1181-1190 ◽  
Author(s):  
J.T. Quinn ◽  
D.J. Hamilton
Keyword(s):  
Diet Composition ◽  
Prey Availability ◽  
Prey Selection ◽  
Bay Of Fundy ◽  
Corophium Volutator ◽  
Stopover Site ◽  
Semipalmated Sandpiper ◽  
Calidris Pusilla ◽  
Isotope Analyses ◽  
Semipalmated Sandpipers

Semipalmated Sandpipers ( Calidris pusilla (L., 1766)) use the upper Bay of Fundy, Canada, as a critical stopover site during their annual fall migration to wintering grounds in South America. While in the area, they feed extensively on mudflat invertebrates. Historically the amphipod Corophium volutator (Pallas, 1766) has been thought to make up the majority of their diet. However, we have recently observed flexibility in foraging behaviour and prey selection by sandpipers. The extent of this flexibility and the current diet composition is unknown. To address these knowledge gaps, we assessed Semipalmated Sandpiper diets using stable isotope analyses of blood plasma and available prey items. Data were collected in two arms of the Bay of Fundy during summer 2009 and 2010. Diets fluctuated between years and sites, but in all cases the diet was much more diverse than previously thought. Polychaetes and biofilm made substantial contributions, and C. volutator was still present in the diet, but at much reduced levels than previously noted. This previously unrecognized inclusion of biofilm in the diet is consistent with recent observations of other calidrid shorebirds. Based on measures of prey availability, there is little evidence of preference for C. volutator.

Effect of forager density on feeding rates in spring-staging Semipalmated Sandpipers (Calidris pusilla) using different foraging modes

2018 ◽  
Vol 96 (9) ◽  
pp. 996-1001 ◽  
Author(s):  
Ivana Novcic ◽  
Guy Beauchamp
Keyword(s):  
Delaware Bay ◽  
Nearest Neighbour ◽  
Feeding Rates ◽  
Stopover Site ◽  
Neighbour Distance ◽  
Short Intervals ◽  
Foraging Modes ◽  
Calidris Pusilla ◽  
Spring Stopover ◽  
Semipalmated Sandpipers

We examined the influence of the density of foragers on feeding rates of Semipalmated Sandpipers (Calidris pusilla (Linnaeus, 1766)) while using different foraging modes at a spring stopover site in Delaware Bay, USA. Using dynamic estimates of interindividual distances obtained at short intervals of time, we explored how forager density affected feeding rates when Semipalmated Sandpipers used visual pecking or tactile probing. Pecking rate significantly increased with interindividual distances, whereas probe rate was not affected by density. Our study also showed that in fast-moving foragers, such as Semipalmated Sandpipers, in which the number of nearby foragers and distance to the nearest neighbour continuously change throughout the foraging bout, pecking rates are more affected by nearest neighbour distance than by the number of foragers in their immediate vicinity. In addition, our study implies that foragers using different foraging modes might be differently affected by nearby competitors perhaps in response to prey disturbance by neighbours.

scholarly journals Body mass and acquisition of breeding plumage of wintering Calidris pusilla (Linnaeus) (Aves, Scolopacidae) in the coast of Pernambuco, north-eastern Brazil

2004 ◽  
Vol 21 (2) ◽  
pp. 249-252 ◽  
Author(s):  
Carmem E. Fedrizzi ◽  
Severino M. de Azevedo Júnior ◽  
Maria E. Lacerda de Larrazábal
Keyword(s):  
Body Mass ◽  
Boreal Summer ◽  
Semipalmated Sandpiper ◽  
Eastern Brazil ◽  
North Eastern ◽  
Breeding Grounds ◽  
Calidris Pusilla ◽  
Breeding Plumage ◽  
The Relationship ◽  
Semipalmated Sandpipers

Annually, large flocks of semipalmated sandpiper Calidris pusilla (Linnaeus, 1766) winter along South America coast, between September-April. They store fats in order to moult and return to their breeding grounds. Here, was examined body masses and plumage of adults Semipalmated Sandpipers during the departure month to evaluate the relationship between body mass and plumage. Fieldwork was conducted at Coroa do Avião (7º40'S, 34º50'W), Pernambuco. Birds were trapped in mist-nets between April 1990 and 1997. They were weighed, and aged according to plumage. Adult plumage may be (1) non-breeding, (2) pre-breeding, and (3) breeding. A total of 213 birds were weighed and examined, so that 8.0% (17) presented non-breeding plumage, 54.0% (115) pre-breeding, and 38.0% (81) breeding plumage. As in Semipalmated Sandpiper, 25g is the minimum body mass required to migrate, birds with breeding plumage and most with pre-breeding, were potentially apt to migrate. Non-breeding plumage birds presented smaller body mass. Apparently physiological problems and infestation may be important factors to explain over-summering, i.e., individuals remaining in the wintering grounds during the boreal summer.

scholarly journals Nest relief in the cryptically-incubating semipalmated sandpiper is quick but vocal

2021 ◽  
Author(s):  
Martin Bulla ◽  
Christina Muck ◽  
Daniela Tritscher ◽  
Bart Kempenaers
Keyword(s):  
Incubation Period ◽  
Monitoring System ◽  
Nest Predation ◽  
Continuous Monitoring ◽  
Low Risk ◽  
Biparental Care ◽  
Semipalmated Sandpiper ◽  
Risk Of Predation ◽  
Calidris Pusilla ◽  
Semipalmated Sandpipers

Biparental care requires coordination between parents. Such coordination might prove difficult if opportunities to communicate are scarce, which might have led to the evolution of elaborate and noisy nest relief rituals in species facing a low risk of predation. However, whether such conspicuous rituals also evolved in species that avoid predation by relying on crypsis remains unclear. Here, we used a continuous monitoring system to describe nest relief behavior during incubation in an Arctic-breeding shorebird with passive nest defense, the semipalmated sandpiper (Calidris pusilla). We then explored whether nest relief behavior provides information about parental cooperation and predicts incubation effort. We found that incubating parents vocalized twice as much before the arrival of their partner than during other times of incubation. In 75% of nest reliefs, the incubating parent left the nest only after its partner had returned and initiated the nest relief. In these cases, exchanges were quick (25s, median) and shortened over the incubation period by 0.1 – 1.4s per day (95%CI), suggesting that parents became more synchronized. However, nest reliefs were not cryptic. In 90% of nest reliefs, at least one parent vocalized, and in 20% of nest reliefs, the incubating parent left the nest only after its returning partner called instantaneously. In 30% of cases, the returning parent initiated the nest relief with a call; in 39% of these cases, the incubating partner replied. If the partner replied, the next off-nest bout was 1 – 4hr (95%CI) longer than when the partner did not reply, which corresponds to an 8 – 45% increase. Our results indicate that incubating semipalmated sandpipers, which rely on crypsis to avoid nest predation, have quick but acoustically conspicuous nest reliefs. Our results also suggest that vocalizations during nest reliefs may be important for the division of parental duties.

Nesting success of yearling and older breeders in the Semipalmated Sandpiper, Calidris pusilla

1983 ◽  
Vol 61 (5) ◽  
pp. 1133-1137 ◽  
Author(s):  
C. L. Gratto ◽  
F. Cooke ◽  
R. I. G. Morrison
Keyword(s):  
Age Groups ◽  
Lower Proportion ◽  
Nesting Success ◽  
Egg Predation ◽  
Hatch Date ◽  
Nest Distribution ◽  
Semipalmated Sandpiper ◽  
Calidris Pusilla ◽  
Two Age Groups ◽  
Semipalmated Sandpipers

Approximately 100 pairs of Semipalmated Sandpipers (Calidris pusilla) nested in a 2-km2 area at La Pérouse Bay, Manitoba, each year from 1980 to 1982. The proportion of nesting yearlings in the population varied from 3 to 10% in different years. Some aspects of the breeding biology of pairs containing at least one yearling were compared with those without yearlings. In 1980, a significantly lower proportion of nests of yearlings were successful (hatched at least one chick) compared with older pairs. In 1981 and 1982 no difference was observed. Nest failure was primarily caused by egg predation. No differences in clutch size or nest distribution were found between the two age groups, but eggs were significantly smaller in nests of yearling females and mean hatch date at yearling nests was later.

Semipalmated Sandpiper (Calidris pusilla)

2020 ◽  
Author(s):  
Peter Hicklin ◽  
Cheri L. Gratto-Trevor
Keyword(s):  
Semipalmated Sandpiper ◽  
Calidris Pusilla

scholarly journals Sex, age, molt strategy, and migration distance explain the phenology of songbirds at a stopover along the East Asian flyway

2021 ◽  
Vol 75 (1) ◽  
Author(s):  
Jonas Wobker ◽  
Wieland Heim ◽  
Heiko Schmaljohann
Keyword(s):  
East Asian ◽  
Russian Far East ◽  
First Year ◽  
Large Set ◽  
Differential Migration ◽  
Breeding Area ◽  
Migration Distance ◽  
Stopover Site ◽  
Evolutionary Response ◽  
Migrant Birds

Abstract Sex- and age-specific differences in the timing of migration are widespread among animals. In birds, common patterns are protandry, the earlier arrival of males in spring, and age-differential migration during autumn. However, knowledge of these differences stems mainly from the Palearctic-African and Nearctic-Neotropical flyways, while detailed information about the phenology of migrant birds from the East Asian flyway is far scarcer. To help fill parts of this gap, we analyzed how migration distance, sex, age, and molt strategy affect the spring and autumn phenologies of 36 migrant songbirds (altogether 18,427 individuals) at a stopover site in the Russian Far East. Sex-differential migration was more pronounced in spring than in autumn, with half of the studied species (6 out of 12) showing a protandrous migration pattern. Age-differences in migration were rare in spring but found in nearly half of the studied species (11 out of 25) in autumn. These age effects were associated with the birds’ molt strategy and the mean latitudinal distances from the assumed breeding area to the study site. Adults performing a complete molt before the onset of autumn migration passed the study site later than first-year birds undergoing only a partial molt. This pattern, however, reversed with increasing migration distance to the study site. These sex-, age-, and molt-specific migration patterns agree with those found along other flyways and seem to be common features of land bird migration strategies. Significance statement The timing of animal migration is shaped by the availability of resources and the organization of annual cycles. In migrant birds, sex- and age-differential migration is a common phenomenon. For the rarely studied East Asian flyway, we show for the first time and based on a large set of migrant songbirds that earlier migration of males is a common pattern there in spring. Further, the timing and extent of molt explained age-differential migration during autumn. Adults molting their complete plumage at the breeding area before migration showed delayed phenology in comparison to first-year birds, which perform only a partial molt. This pattern, however, reversed with increasing migration distance to the study site. Since our results agree with the general patterns from the other migration flyways, similar drivers for differential migration may act across different flyway systems, provoking a similar evolutionary response.

Effect of flooding on palearctic migrant birds at the eilat stopover site in israel

2009 ◽  
Vol 28 (3) ◽  
pp. 291-299 ◽  
Author(s):  
P. Zduniak ◽  
R. Yosef ◽  
P. Tryjanowski
Keyword(s):  
Stopover Site ◽  
Migrant Birds
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