Some aspects of the foraging ecology of migrant juvenile sandpipers in the outer Bay of Fundy

Thirty-seven sandpipers (29 semipalmated and 8 least) were collected in early September 1983 on an intertidal flat on the outer Bay of Fundy. Analysis of esophagus and gizzard contents revealed a variety of benthic invertebrates but the diets of both species were dominated by the amphipod Corophium volutator (Pallas). Females of both species ate larger Corophium than did males of the same species. Both least and semipalmated sandpipers were underutilizing a cohort of large (7–10 mm) Corophium. It is possible that the large amphipods have reached a size refuge from predation such that the energy required to handle and ingest these large prey offsets too great a portion of the energy obtained.

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

Canadian Journal of Zoology ◽

10.1139/z2012-086 ◽

2012 ◽

Vol 90 (9) ◽

pp. 1181-1190 ◽

Cited By ~ 24

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.

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Selection of foraging sites and invertebrate prey by migrant Semipalmated Sandpipers, Calidris pusilla (Pallas), in Minas Basin, Bay of Fundy

Canadian Journal of Zoology ◽

10.1139/z84-321 ◽

1984 ◽

Vol 62 (11) ◽

pp. 2201-2210 ◽

Cited By ~ 82

Author(s):

Peter W. Hicklin ◽

P. C. Smith

Keyword(s):

Visual Cues ◽

Size Composition ◽

Fine Sand ◽

Bay Of Fundy ◽

Particle Sizes ◽

Corophium Volutator ◽

Prey Behavior ◽

Coarse To Fine ◽

Selection Of ◽

Semipalmated Sandpipers

We determined the particle size composition of substrates, the species composition and abundances of mud-dwelling invertebrates, and the distribution, densities, and diets of Semipalmated Sandpipers foraging on different mud flats in Minas Basin, Bay of Fundy, during the birds' southward migration. Substrate types varied between the mud flats used by shorebirds; particle sizes ranged from sandy (coarse to fine sands) to muddy (mainly silt and clay). Of 34 species of invertebrates identified, the polychaetes Spiophanes bombyx (Clarapede) and Heteromastus filiformis (Clarapede) and the amphipod Corophium volutator (Pallas) were the most numerous and widely distributed. Spiophanes and the "bamboo" worm Clymenella torquata (Leidy) were more abundant in coarse sandy substrates whereas numbers of Heteromastus were negatively correlated with grain size. The densities of Corophium were positively correlated with the amount of very fine sand in the substrate. The sandpipers foraged in larger numbers on mud flats where densities of Corophium were greatest and it was the main prey taken at those sites. The birds' diet was more diverse in areas of low Corophium density. It appears that the birds use visual cues for foraging and that prey behavior is particularly important in their choice of prey items.

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Fatty acid composition and concentration of alternative food of Semipalmated Sandpipers (Calidris pusilla) in the upper Bay of Fundy, Canada

Canadian Journal of Zoology ◽

10.1139/cjz-2016-0246 ◽

2017 ◽

Vol 95 (8) ◽

pp. 565-573 ◽

Cited By ~ 8

Author(s):

J.T. Quinn ◽

D.J. Hamilton ◽

C.E. Hebert

Keyword(s):

Fatty Acid ◽

Substantial Part ◽

Bay Of Fundy ◽

Corophium Volutator ◽

Fa Composition ◽

Quality Of Food ◽

Calidris Pusilla ◽

Migrating Birds ◽

Semipalmated Sandpipers

Semipalmated Sandpipers (Calidris pusilla (L., 1766)) that migrate through the upper Bay of Fundy, Canada, depend on a rich food supply to fuel their continued migration. Although past studies have reported a diet dominated by the amphipod Corophium volutator (Pallas, 1766), an animal rich in n–3 polyunsaturated fatty acids (PUFAs), recent evidence suggests that sandpiper diets are broad. This is beneficial in that it allows Semipalmated Sandpipers to respond to a changing food base, but quality of food is also important. PUFAs are important in providing the energy required by migrating birds and may play a role in migratory preparation. We assessed fatty acid (FA) concentrations and proportions in three common food items. We found that polychaetes should adequately meet the needs of migrating sandpipers in terms of FA composition. Concentrations of FAs in biofilm were low, but proportionally, n–3 PUFAs were well represented, particularly in biofilm collected in Shepody Bay, where it forms a substantial part of the sandpiper diet. Therefore, provided that birds can consume a sufficient volume of biofilm, it is also probably a suitable source of essential FAs. Our results suggest that Semipalmated Sandpipers in the Bay of Fundy can meet their FA needs with a variety of dietary options.

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Spatial distribution of the intertidal snail Ilyanassa obsoleta in relation to parasitism by two species of trematodes

Canadian Journal of Zoology ◽

10.1139/z00-038 ◽

2000 ◽

Vol 78 (7) ◽

pp. 1137-1143 ◽

Cited By ~ 14

Author(s):

Dean G McCurdy ◽

J Sherman Boates ◽

Mark R Forbes

Keyword(s):

Spatial Distribution ◽

Intertidal Zone ◽

Bay Of Fundy ◽

Spatial Distributions ◽

Ilyanassa Obsoleta ◽

Intermediate Hosts ◽

Corophium Volutator ◽

Vertical Distributions ◽

Second Intermediate Host ◽

Intertidal Snail

We studied the spatial distributions of mud snails (Ilyanassa obsoleta) infected by two trematodes, Lepocreadium setiferoides and Gynaecotyla adunca, on a macrotidal mudflat in the Minas Basin, Bay of Fundy. Snails, as first intermediate hosts, were castrated by both parasites, and we found no evidence of sex differences in parasitism. Similar to previous work, prevalence of L. setiferoides in I. obsoleta increased exponentially with host size (and age). Unexpectedly, prevalence of G. adunca decreased over the largest size classes of snails, a result that may be due to several causes. Distributions of both parasites across the intertidal zone differed from previous accounts in that snails infected with L. setiferoides were found only in the middle of the intertidal zone, whereas prevalence of G. adunca increased exponentially moving seaward. Several species of polychaetes could be infected by L. setiferoides in the laboratory and may act as appropriate second intermediate hosts, whereas only the amphipod Corophium volutator served as a second intermediate host for G. adunca. Finally, the vertical distributions of I. obsoleta infected by either species of trematode overlap with distributions of apparent or known second intermediate hosts.

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Crawling behaviour of the amphipod Corophium volutator and foraging by Semipalmated Sandpipers, Calidris pusilla

Canadian Journal of Zoology ◽

10.1139/z89-066 ◽

1989 ◽

Vol 67 (2) ◽

pp. 457-462 ◽

Cited By ~ 34

Author(s):

J. Sherman Boates ◽

Peter C. Smith

Keyword(s):

Nova Scotia ◽

Food Intake ◽

Lunar Cycle ◽

Intertidal Mudflat ◽

Sharp Reduction ◽

Corophium Volutator ◽

Quantitative Evidence ◽

Qualitative And Quantitative ◽

Calidris Pusilla ◽

Semipalmated Sandpipers

During late spring and summer, the crawling behaviour of the amphipod Corophium volutator was studied on an intertidal mudflat in the Minas Basin, Nova Scotia. On average, less than 1% of the population crawled on any tide and these individuals tended to be large adults that were predominantly males. Animals emerged as the tide receded but most had crawled into burrows after 25 min. The crawling behaviour did not seem to be related to the lunar cycle as was expected; however, there was a sharp reduction in crawling activity (from 36.3 to 1.2 amphipods/m2) in July that coincided with the arrival of Semipalmated Sandpipers, Calidris pusilla, an abundant seasonal predator. The proportion of males in the amphipod population declined during the period when sandpipers were present. It appears that both a change in amphipod behaviour and depletion of the animals most prone to crawling may contribute to the observed reduction in crawling activity. Qualitative and quantitative evidence show that sandpipers were attracted to the tide edge where crawling amphipods were relatively abundant and that they increased their food intake by doing so.

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