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Atypical Feeding Behavior of Long-tailed Ducks in the Wake of a Commercial Fishing Boat while Clamming
Matthew C. Perry, Peter C. Osenton, and Timothy P. White

Northeastern Naturalist, Volume 24, Issue 2 (2017): N19–N25

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N19 2017 Northeastern Naturalist Notes Vol. 24, No. 2 M.C. Perry, P.C. Osenton, and T.P. White Atypical Feeding Behavior of Long-tailed Ducks in the Wake of a Commercial Fishing Boat while Clamming Matthew C. Perry1,*, Peter C. Osenton1, and Timothy P. White2 Abstract - A foraging group of Clangula hyemalis (Long-tailed Duck) was observed on 10 February 2010 diving behind a commercial boat that was clamming near Monomoy Island, Nantucket Sound, MA. We used a shotgun to collect 9 of the ducks, and our analyses of gizzard and gullet (esophagus and proventriculus) revealed 37 food items in the gizzard and 16 in the gullet. Mollusca were the dominant food in the gizzard (49%), whereas Crustacea were dominant in the gullet (57%). Crustacea were the second most important food in the gizzard (38%), whereas Mollusca were the second most important food in the gullet (31%). Relatively high volumes of the Amphipoda Caprella sp. (skeleton shrimp) and the Decopoda Crangon septemspinosa (Sand Shrimp) were recorded in the gullet and gizzard. Ensis directus (Atlantic Jackknife Clam) formed the greatest volume of Mollusca in the gizzard (15%) and in the gullet (15%). Long-tailed Ducks had fed on this Bivalvia and several other species of Mollusca that had no shell or broken shell when consumed. Many of the food organisms were apparently dislodged and some damaged by the clamming operation creating an opportunistic feeding strategy for the Long-tailed Ducks. Marine birds are known to feed opportunistically on organisms captured by and discarded from fishing vessels (Dare 1982, Furness and Monaghan 1987, Griffiths 1982, Hudson and Furness 1988, Leopold 2002). Birds will also respond to natural prey made available by the vessel’s propeller wash (Camphuysen 1996, Eades 1982, Perry 2012). On 10 February 2010, we used a shotgun to collect (US Fish and Wildlife Permit MB034670-1) a total of 9 Clangula hyemalis L. (Long-tailed Duck) that were diving in the wake of a keeled clamming boat ~10 m (32 ft) long with an inboard motor. The boat was clamming near Rodger’s Shoal, Nantucket Sound, MA, and ~1.6 km (1 mile) northwest of Monomoy Point in water ~5 m (16 ft) deep. The clamming boat was using a dredge to most likely obtain large clams, such as Mercenaria mercenaria (Northern Quahog) and Spisula solidissima (Atlantic Surfclam). Smaller clams and other organisms are not collected by the dredge, but are disturbed and damaged during the operation (G.M. Haramis, USGS Patuxent Wildlife Research Center, Laurel, MD, 2006 pers. observ.) There were ~50 ducks diving in the wake of the clamming boat with dredge, but we saw no other ducks in the area of the clamming operation. Analyses of gizzard and gullet (esophagus and proventriculus) using traditional techniques (Perry and Uhler 1988) revealed both soft-and hard-bodied benthic organisms that may have been disturbed by the dredge. We identified a large number of food items in the gizzard (37 items) and gullet (16 items) (Table 1). The high variability of prey items ingested by the 9 ducks supports previous findings that Long-tailed Ducks use a flexible foraging strategy to locate food at sea (Robertson and Savard 2002). Frequency of occurrences of the food organisms also had high variability in the gizzard (11–100%) and in the gullet (14–100%). Amphipoda were the only food organisms occurring in all gizzard and gullet samples. Mollusca were the dominant food in the gizzard (49%), whereas Crustacea were dominant in the gullet (57%). 1USGS Patuxent Wildlife Research Center, 12100 Beech Forest Road, Laurel, MD 20708. 2Department of the Interior, Bureau of Ocean Energy Management, Division of Environmental Sciences, Branch of Biological and Social Sciences, 45600 Woodland Road, Sterling, VA 20166. *Corresponding author - mperry1209@verizon.net. Manuscript Editor: Jean-Pierre L. Savard Notes of the Northeastern Naturalist, Issue 24/2, 2017 2017 Northeastern Naturalist Notes Vol. 24, No. 2 N20 M.C. Perry, P.C. Osenton, and T.P. White Table 1. Prey items ingested by 9 Long-tailed Ducks feeding in the wake of a clamming boat, near Monomoy Island, Nantucket Sound, MA, 2010. All organisms are maintained in the reference collection at USGS Patu xent Wildlife Research Center food habits laboratory. Gizzard food (n = 9) Gullet food (n = 7) Common name Scientific name Mean (SD) Freq. of occur. % Mean ( SD) Freq. of occur. % Unknown crustacean Crustacea 15.77 (20.46) 67 Atlantic Jackknife Clam Ensis directus Conrad 15.40 (11.84) 78 14.72 (27.38) 71 Skeleton shrimp Caprella sp. 9.30 (27.89) 11 8.98 (23.77) 14 Unknown bivalve Bivalvia 6.10 (8.360 78 Atlantic Surfclam Spisula solidissima (Dillwyn) 5.85 (8.99) 67 1.31 (2.89) 29 Lunar Dovesnail Mitrella lunata (Say) 5.82 (8.40) 100 0.94 (2.36) 43 Atlantic Awningclam Solemya velum Say 5.68 (5.15) 78 2.23 (3.89) 57 Unknown amphipod Amphipoda 5.47 (5.44) 89 30.36 (23.42) 100 Detritus 4.89 (11.28) 78 0.41 (0.96) 29 Unknown fish Pisces 4.65 (13.88) 22 3.79 (10.03) 14 Sand Shrimp Crangon septemspinosa Say 3.74 (10.06) 78 12.6 (23.92) 71 Atlantic Nutclam Nucula proxima Say 3.11 (5.88) 78 0.02 (0.05) 14 Bloodworm species Glycera sp. 2.62 (6.28) 78 5.48 (9.40) 29 Unknown barnacle Cirrepedia 2.22 (4.70) 44 Miniature Moonsnail Tectonatica pusilla (Say) 1.69 (4.72) 56 Mounded-back Isopod Edotia triloba (Say) 1.23 (1.53) 78 4.93 (6.70) 86 False Quahog Pitar morrhuanus (Linsley) 1.05 (3.15) 11 0.03 (0.07) 14 Gould’s Pandora Pandora gouldiana Dall 0.87 (2.54) 22 Greedy Dovesnail Costoanachis avara (Say) 0.61 (1.75) 22 Northern Dwarf Tellin Tellina agilis Stimpson 0.60 (0.89) 44 1.19 (2.60) 57 Unknown crab Decopoda 0.48 (0.80) 56 0.08 (0.14) 29 Shark Eye Neverita duplicata (Say) 0.43 (1.30) 11 Unknown bivalve two Bivalvia 0.43 (1.30) 11 Northern Quahog Mercenaria mercenaria L. 0.29 (0.88) 11 Inornate Pandora Pandora inornata A.E. Verrill & Bush 0.26 (0.77) 11 N21 2017 Northeastern Naturalist Notes Vol. 24, No. 2 M.C. Perry, P.C. Osenton, and T.P. White Table 1, continued. Gizzard food (n = 9) Gullet food (n = 7) Common name Scientific name Mean (SD) Freq. of occur. % Mean ( SD) Freq. of occur. % Common Sand Dollar Echinarachnius parma (Lamarck) 0.26 (0.77) 11 Common Atlantic Slippersnail Crepidula fornicata (L.) 0.20 (0.33) 44 Glassy Lyonsia Lyonsia hyalina Conrad 0.20 (0.32) 44 0.44 (1.05) 29 Unknown hydroid Hydrozoa 0.17 (0.13) 67 0.41 (0.66) 57 Unknown gastropod Gastropoda 0.16 (0.13) 67 0.08 (0.12) 14 Yoldia species Yoldia sp. 0.15 (0.14) 56 Unknown mollusk Mollusca 0.13 (0.32) 22 10.28 (27.19) 14 Turbonille species Turbonilla sp. 0.07 (0.11) 33 Threelined Mudsnail Nassarius trivittatus (Say) 0.07 (0.10) 33 Transverse Ark Anadara transversa (Say) 0.07 (0.14) 22 0.04 (0.12) 14 Well-ribbed Dovesnail Costoanachis lafresnayi (P. Fischer & 0.06 (0.12) 22 Bernardi) Channeled Barrel-bubble Acteocina canaliculata (Say) 0.05 (0.10) 22 Erichsonella Isopod Erichsonella filiformis (Say) 0.04 (0.11) 11 Pondweed species seed Potamogeton sp. 0.03 (0.08) 11 Unknown isopod Isopoda 0.03 (0.10) 11 0.25 (0.53) 29 Baltic Isopod Idotea balthica (Pallas) 0.02 (0.06) 11 0.04 (0.12) 14 Blue Mussel Mytilus edulis L. 0.02 (0.07) 11 0.04 (0.12) 14 Solitary Glassy-bubble Haminoea solitaria (Say) 0.02 (0.07) 11 Stout Tagelus Tagelus plebeius (Lightfoot) 0.02 (0.07) 11 Clamworm species Neanthes sp. 0.02 (0.07) 11 0.03 (0.10) 14 Nut clam species Nucula sp. 0.02 (0.07) 11 Toad crab species Hyas sp. 0.02 (0.05) 11 Unknown animal matter Animalia 0.95 (2.50) 14 Unknown sponge Porifera 0.22 (0.57) 14 One-pointed Isopod Idotea phosphorea Harger 0.10 (0.26) 14 Unknown vegetation Plantae 0.03 (0.07) 14 2017 Northeastern Naturalist Notes Vol. 24, No. 2 N22 M.C. Perry, P.C. Osenton, and T.P. White Crustacea were the second most important food in the gizzard (38%), whereas Mollusca were the second most important food in the gullet (31%). This reversal of observed quantities of food itmes between the gizzard and gullet is most likely due to the bias created by grinding of soft-bodied food in the gizzard (Swanson and Bartonek 1970). Relatively high volumes of the Amphipoda Caprella sp. (skeleton shrimp), and the Decopoda Crangon septemspinosa (Sand Shrimp) were recorded in the gullet (9% and 13%, respectively) and gizzard (9% and 4%, respectively). The observed volumes of skeleton shrimp and Sand Shrimp recorded in this sample were higher than those recorded in a previous study (White et al. 2009). These species are believed to be mainly benthic organisms and are not typically consumed by Long-tailed Ducks (White et al. 2009). Skeleton shrimp were observed in some of the 35 Long-tailed Ducks analyzed in Chesapeake Bay by the authors (M.C. Perry and P.C. Osenton, unpubl. data), but average percentage was less than 1%. Cottam (1939) reported just over 1% by volume of skeleton shrimp in his sample of Long-tailed Ducks. Sand Shrimp was not noted in the Chesapeake Bay sample or in the Cottam (1939) sample. Amphipods ingested by Long-tailed Ducks in fresh water of Lake Michigan included Pontoporeia affinis Lindstrum and P. hoyi Smith (Lagler and Wienert 1948, Peterson and Ellarson 1977). In salt water, Calliopius laeviusculus Kroyer, Gammarellus angulosus Rathke, Onisimus glacialis Sars, Parathemisto spp., Gammarus spp., and Caprella spp. are consistently documented diet items of Long-tailed Ducks (Cottam 1939, Goudie and Ankney 1986, Jamieson et al. 2001, Johnson 1984). Isopoda constituted 1% of the gizzard contents and 5% of the gullet contents. Edotia triloba (Mounded-backed Isopod) and Idotea balthica (Baltic Isopod) were identified in both the gizzard and gullet, but Idotea phosphorea (One-pointed Isopod) was found only in the gullet. Baltic Isopod was determined to be an important food item for Long-tailed Ducks in Newfoundland (Goudie and Ankney 1986). We did not find Mysidacea (mysid shrimp) in the 9 birds in this sample. Mysid Shrimp are bottom-dwelling organisms and therefore might have been expected in this group of ducks as in other studies (Robertson and Savard 2002). Important mysid species in other samples include Mysis litoralis (A.H. Banner), M. relicta Lovén, and Thysanoessa spp. (Cottam 1939, Johnson 1984). Decopoda other than Sand Shrimp that were found in this sample included Hyas sp. (toad crab), which was in the gizzard. Other Decopoda eaten by Long-tailed Ducks in other areas include crabs (Cancer spp., Panopeus herbstii H. Milne Edwards [Atlantic Mud Crab], Dispanopeus sayi (S.I. Smith) [Say Mud Crab], Hexapanopeus angustifrons (Benedict and Rathbun) [Smooth Mud Crab]), the fairy shrimp Lepidurus glacialis Packard, Crago spp. shrimp, and Pandalus goniurus Stimpson (Humpy Shrimp) (Cottam 1939, McGilvrey 1967, Sanger and Jones 1984). Ensis directus (Atlantic Jackknife Clam) formed the greatest volume of Mollusca in the gizzard (15%) and in the gullet (15%). Long-tailed Ducks had fed on this Bivalvia and several other species of Mollusca that had no shell or broken shell in the gizzard or gullet. Thus, most of the food found in both the gizzard and the gullet was meat that appeared to be broken free of the shell during the clamming operation. The size of the clam meat in some of the samples appeared to originate from clams larger than typically eaten by Longtailed Ducks. The breaking of shells by the dredge makes for faster and energetically more economical foraging by getting a larger quantity of meat without wasting energy grinding shells (Wells-Berlin et al. 2015). We found unidentified fish in the gizzard (5%) and the gullet (4%), and observed unidentified vegetation in the gullet of 1 duck and seeds of Potamogeton sp. (pondweed species) N23 2017 Northeastern Naturalist Notes Vol. 24, No. 2 M.C. Perry, P.C. Osenton, and T.P. White in the gizzard of 1 duck. We observed an unidentified Hydrozoa (hydroid) in gizzards and gullets of several ducks, but it comprised less than 1% of the average volume. We also noted remains of Echinarachnius parma (Common Sand Dollar) in the gizzard of 1 duck, but not in any of the gullets of the ducks. Detritus constituted 5% of the material in the gizzards and less than 1% in the gullets. The detritus was organic and included items such as unidentifiable twigs and pieces of wood that were probably ingested because they had food items attached. In Chesapeake Bay, 2 Long-tailed Ducks were collected in the 1990s that had wire from a crab pot in their gizzard that was most likely eaten due to the Cirrepedia (Barnacles) and other live organisms that typically attach to old deserted crab pots (M.C. Perry, unpubl. data). Several species of benthic organisms (e.g., One-pointed Isopod and Anachis avara [Greedy Dovesnail]) were recorded that are not generally preyed on by Long-tailed Ducks. These uncommon diet items are further evidence that many of the food organisms were apparently dislodged by the clamming operation creating an opportunistic feeding strategy for the Long-tailed Ducks. This sample of ducks from the Monomoy Island area had high volumes of unidentified Crustacea and unidentified Amphipoda in the gullets and gizzards of the ducks. It is most likely that these unidentified food items were benthic Sand Shrimp or skeleton shrimp disturbed and damaged by the clamming dredge. It is unlikely that the unidentified Crustacea and Amphipoda were Gammarus annulatus S.I. Smith (a pelagic amphipod) as none of this common mobile organism in the water column was identified in the gullet or gizzard of the 9 ducks. This organism has been commonly found in deeper water (15–23 m [50–75 ft]) in the Atlantic Ocean south of Nantucket Island in dense concentrations, which is believed to be the reason Long-tailed Ducks were making the long daily commute to the ocean in the morning and then returning to Nantucket Sound at night (White et al. 2009). We identified a total of 37 different types of food organisms in gizzards and16 in gullets of the 9 ducks collected. All organisms found in the gullet were also found in the gizzard except for Porifera (unknown sponge) and One-pointed Isopod. An average of 10.3 species was identified in gizzards and 3.5 species in gullets. The proportion of food items that could not be identified to the species level of taxonomy amounted to 48% for gizzard and 63% for gullet samples (tally from Table 1), so the overall species diversity was likely higher. This dietary diversity is relatively high compared to other observations. In Chesapeake Bay, a total of 22 different organisms were found in gizzards (n = 35) and 7 in gullets (n = 10) of Long-tailed Ducks analyzed for food by the authors (M.C. Perry and P.C. Osenton, unpubl. data). Cottam (1939) reported an average of fewer than 6.5 species per gizzard of 190 adult Long-tailed Ducks collected in 11 months of the year from several areas of North America. Feeding activity near the clam boat was similar to activity of Long-tailed Ducks observed diving in the wake of the Nantucket ferry (Perry 2012), as we saw some flying to the area and then immediately diving close to the dredging area. Our analysis of gizzards and gullets confirms the presence of a large number of food organisms in the Nantucket Sound area and a foraging strategy associated with human activity to access that food. In both cases, the Long-tailed Ducks appeared to be ingesting food items that were readily available due to the actions of the boats. Ingesting sponges, which are not commonly eaten by Long-tailed Ducks, suggests that they are not specific of what they eat, but of what is readily available and abundant, similar to what was reported by Robertson and Savard (2002). The generalist nature of the feeding seems especially likely due to the foods being ingested in an environment that had high turbidity from the dredging. This is another example of opportunistic foraging by Long-tailed Ducks in Nantucket Sound (Perry 2012). 2017 Northeastern Naturalist Notes Vol. 24, No. 2 N24 M.C. Perry, P.C. Osenton, and T.P. White Observations from the ground and air indicates that the vast majority of Long-tailed Ducks in the Nantucket Island area are in Nantucket Sound at night, but depart daily and feed in the ocean during the day (Davis 1997, Perkins 1988, White et al. 2009). It has been hypothesized that this daily movement could have evolved from the presence of more predators in the ocean than in Nantucket Sound (Perry et al. 2013). However, the observations and analyses reported here indicate that some Long-tailed Ducks remain in Nantucket Sound during the day and have adapted to human activity from a clamming boat, as reported here, or the Nantucket ferry, as reported previously (Perry 2012). Long-tailed Ducks are small-bodied ducks with a high metabolic rate; thus, they are predicted to maximize energy, spending more time searching for and feeding upon soft-bodied prey than handling and grinding shelled prey, especially in winter (Sanger and Jones 1984, Systad et al. 2000). Clamming operations on Nantucket Sound may expose and aggregate energy-dense food sources such as clams and crustaceans to smaller diving ducks that expend less time loafing and more time searching for food than larger sea ducks. More observations and studies need to be conducted to further document this connection between human activities and feeding during the day in the Nantucket Sound by Long-tailed Ducks. Acknowledgments. Technical and editorial comments were provided by T. Alison, A. Berlin, S. Boyd, L. Garrett, J. Gonnelli, R. Kennedy, K. Laurent, V. Laux, G. Olsen, S. Perkins, and J.-P. Savard. The use of trade, product, or firm names in this publication is for descriptive purposes only and does not imply endorsement by the US Government. Literature Cited Camphuysen, K.C.J. 1996. Observation of a feeding Little Auk on Texel, November 1995. Sula 10:247–248. Cottam, C. 1939. Food habits of North American diving ducks. USDA, Technical Bulletin No. 643, Washington, DC. 140 pp. Dare, P.J. 1982. Notes on sea birds attending a commercial trawler fishing in shelf waters off Ireland in summer. Seabird Report 1977-81:110–114. Davis, W.E., Jr. 1997. The Nantucket Oldsquaw flight: New England’s greatest bird show? Bird Observer 25(1):16–22. Eades, R.A. 1982. Notes on the distribution and feeding of Little Gulls at sea in Liverpool Bay. Seabird Report 1977-81:115–121. Furness, R.W., and Monaghan, P. 1987. Seabird Ecology. Blackie, Glasgow, Scotland, UK. 164 pp. Goudie, R.I., and C.D. Ankney. 1986. Body size, activity budgets, and diets of sea ducks wintering in Newfoundland. Ecology 67:1475–1482. Griffiths, A.M. 1982. Reactions of some seabirds to a ship in the southern ocean. Ostrich 53:228–235. Hudson, A.V., and R.W. Furness. 1988. The behaviour of seabirds foraging at fishing boats around Shetland. Ibis 131:225–237. Jamieson, S.E., G.J. Robertson, and H.G. Gilchrist. 2001. Autumn and winter diet of Long-tailed Ducks wintering in the Belcher Islands, Nunavut, Canada. Waterbirds 23:129–132. Johnson, S.R. 1984. Prey selection by Oldsquaws in a Beaufort Sea lagoon, Alaska. Pp. 12–19, In G.A. Sanger and P.F. Springer (Eds.). Marine Birds: Their Feeding Ecology and Commercial Fisheries Relationships. Canada Wildlife Service Special Publication, Ottawa, ON, Canada. Lagler, K.F., and C.C. Wienert. 1948. Food of the Old-squaw in Lake Michigan. Wilson Bulletin 60:118. Leopold, M.F. 2002. Eiders, Somateria mollissima, scavenging behind a lugworm boat. Journal of Sea Research 47(1):75–82. McGilvrey, F.B. 1967. Food habits of sea ducks from the northeastern United States. Wildfowl Trust Annual Report 18:142–145. Perkins, S. 1988. Watching Oldsquaws. Sanctuary 28(3):23. Perry, M.C. 2012. Foraging behavior of Long-tailed Ducks in a ferry wake. Northeastern Naturalist 19(1):135–139. N25 2017 Northeastern Naturalist Notes Vol. 24, No. 2 M.C. Perry, P.C. Osenton, and T.P. White Perry, M.C., and F.M. Uhler. 1988. Food habits and distribution of wintering Canvasbacks (Aythya valisineria) on Chesapeake Bay. Estuaries 11:57–67. Perry, M.C., G.H. Olsen, R. Richards, P.C. Osenton. 2013. Predation on Dovekies by Goosefish over deep water in the Northwest Atlantic. Northeastern Naturalist 20(1):148–154. Peterson, S.R., and R.S. Ellarson. 1977. Food habits of Oldsquaws wintering on Lake Michigan. Wilson Bulletin 89:81–91. Robertson, G.J., and J.-P.L. Savard. 2002. Long-tailed Duck (Clangula hyemalis). Pp. 1–28, In A. Poole and F. Gill (Eds.). The Birds of North America, No. 651. The Birds of North America, Inc., Philadelphia, PA. Sanger, G.A., and. R.D. Jones, Jr. 1984. Winter feeding ecology and trophic relationships of Oldsquaws and White-winged Scoters on Kachemak Bay, Alaska. Pp. 20–28, In D.N. Nettlehsip, G.A. Sanger, and P.F. Springer (Eds.). Marine Birds: Their Feeding Ecology and Commercial Fisheries Relationships. Canada Wildlife Service Special Publication, Ottawa, ON, Canada. Systad, G.E., J.O. Bustnes, and K.E. Erikstad. 2000. Behavioral responses to decreasing day length in wintering sea ducks. Auk 117:33–40. Swanson, G.A., and J.C. Bartonek. 1970. Bias associated with food analysis in gizzards of Bluewinged Teal. Journal of Wildlife Management 34:739–746. Wells-Berlin, A.M., M.C. Perry, R.A. Kohn, K.T. Paynter Jr., and M.A. Ottinger. 2015. Composition, shell strength, and metabolizable energy of Mulinia lateralis and Ischadium recurvum as food for wintering Surf Scoters (Melanitta perspicillata). PLoS ONE 10(5):e0119839. White, T.P., R.R. Veit, and M.C. Perry. 2009. Feeding ecology of Long-tailed Ducks Clangula hyemalis wintering on the Nantucket Shoals. Waterbirds 32(2):293–299.