Intra- and inter-specific competition between Barrow's goldeneye (Bucephala islandica) and bufflehead (Bucephala albeola)

1982 ◽  
Vol 60 (12) ◽  
pp. 3439-3446 ◽  
Author(s):  
Jean-Pierre L. Savard
Keyword(s):  
Intraspecific Aggression ◽  
Dabbling Ducks ◽  
Interspecific Aggression ◽  
Diving Ducks ◽  
Bucephala Islandica ◽  
Bucephala Albeola ◽  
Food Competitor

Barrow's goldeneye and bufflehead pairs defend well-delineated territories from which they exclude conspecifics. Only the male defends the territory and does so even when the female is absent. However, after the young have hatched, females of both species defend brood territories from which they exclude conspecifics. Both species are also interspecifically territorial. Barrow's goldeneye and bufflehead drakes threatened and (or) attacked 15 and 11 species, respectively. However, 55% of Barrow's goldeneye interspecific encounters were with bufflehead and 52% of bufflehead encounters were with Barrow's goldeneye. Barrow's goldeneye drakes always excluded bufflehead from their territory whereas bufflehead drakes successfully excluded yearlings, females, and unpaired Barrow's goldeneye drakes but were usually dominated by paired males. Female Barrow's goldeneye excluded all bufflehead from the brood territory and were particularly aggressive toward bufflehead broods. Food and mates are the most likely defended resources in intraspecific encounters. In interspecific encounters diving ducks were more violently attacked than dabbling ducks indicating that food may be the defended resource. Interspecific aggression of Barrow's goldeneye toward bufflehead does not appear to be misdirected intraspecific aggression but rather a directed aggression toward a food competitor and may therefore be adaptive.

Interspecific Aggression By Barrow's Goldeneye: a Descriptive and Functional Analysis

Behaviour ◽  
1987 ◽  
Vol 102 (3-4) ◽  
pp. 168-183 ◽  
Author(s):  
JEAN-PIERRE L. Savard ◽  
James N.M. Smith
Keyword(s):  
Functional Analysis ◽  
Feeding Habits ◽  
Breeding Habitat ◽  
Dabbling Ducks ◽  
Interspecific Aggression ◽  
Diving Duck ◽  
Diving Ducks ◽  
Dabbling Duck ◽  
Common Goldeneye ◽  
Intraspecific Aggressiveness

AbstractWe describe interspecific aggression and territoriality by a diving duck, the Barrow's goldeneye. Males of this species are strongly interspecifically territorial early during the breeding season, and in winter. Females are interspecifically territorial while tending broods of ducklings. Aggression was strongest against conspecifics, and against the con-generic bufflehead, which shares the same breeding habitat. Other diving ducks, which overlap in diet with goldeneyes, were frequently attacked, while dabbling ducks, with differing feeding habits, were generally tolerated, and were seldom attacked. One dabbling duck, the blue-winged teal, in which the drake resembles the Barrow's goldeneye drake in plumage, was attacked more strongly than other dabblers. We propose that the strong interspecific aggressiveness exhibited by the Barrow's goldeneye, and its congeners the bufflehead and common goldeneye, is a consequence of the strong intraspecific aggressiveness of these species. Selectivity in aggression towards victims of different species can be explained by two hypotheses. Species that have (1) similar diets, and (2) similar plumages to Barrow's goldeneye are selectively attacked.

Body and organ mass dynamics during remigial moult in a wing–foot-propelled diving sea duck: the Common Eider (Atlantic) (Somateria mollissima dresseri)

2015 ◽  
Vol 93 (10) ◽  
pp. 755-764 ◽  
Author(s):  
A. Viain ◽  
M. Guillemette ◽  
J.-P.L. Savard
Keyword(s):  
Muscle Mass ◽  
Body Mass ◽  
Flight Muscle ◽  
Somateria Mollissima ◽  
Dabbling Ducks ◽  
Diving Ducks ◽  
Common Eiders ◽  
Sea Duck ◽  
Remigial Moult ◽  
Atrophy Of The Heart

Body and organ dynamics, during remigial moult, have been mainly explored on geese, dabbling ducks, and foot-propelled diving ducks, but weakly on sea ducks. This study investigated the internal changes in a wing–foot-propelled sea duck to determine the adaptive strategies implemented. Forty-five male Common Eiders (Atlantic) (Somateria mollissima dresseri Sharpe, 1871), collected in the Gulf of St. Lawrence, were dissected; their body mass, muscle mass, and organ sizes were measured. We tested three hypotheses: (1) S. m. dresseri use a strategic reduction of body mass to reduce the flightlessness duration; (2) organs will exhibit changes consistent with a trade-off between function and maintenance to save and reallocate energy and proteins to feather growth; (3) S. m. dresseri would show lower flight muscle reduction than foot-propelled diving ducks. Somateria mollissima dresseri did not lose body mass, which does not support the first hypothesis. Atrophy of the heart followed by hypertrophy and opposite changes in leg muscle mass and gizzard mass are consistent with the second hypothesis. Flight muscle mass showed lower variations than in other ducks, validating the third hypothesis. We also suggest that the lipid depletion observed early in the moult could be a strategy to reduce foraging effort and minimize the risk of damaging the growing feathers.

Comparative migration, growth and development of Typhlocoelum cucumerinum sisowi in dabbling ducks and Typhlocoelum cucumerinum cucumerinum in diving ducks

Parasitology ◽  
1982 ◽  
Vol 84 (2) ◽  
pp. 333-350 ◽  
Author(s):  
Marilyn E. Scott ◽  
M. E. Rau ◽  
J. D. McLaughlin
Keyword(s):  
Life Cycle ◽  
Life Span ◽  
Definitive Host ◽  
Host Species ◽  
Growth And Development ◽  
Abdominal Cavity ◽  
Dabbling Ducks ◽  
Diving Ducks ◽  
Air Sacs ◽  
Aythya Valisineria

SUMMARYExperimental infections of mallards (Anas platyrhynchos L.) with Typhlocoelum cucumerinum sisowi (Skrjabin, 1913) and of canvasbacks (Aythya valisineria (Wilson)) with Typhlocoelum cucumerinum cucumerinum (Rudolphi, 1809) revealed significant differences in various parameters of the life-cycle in the definitive host. Both T. c. sisowi and T. c. cucumerinum migrate to the trachea via the abdominal cavity, air sacs and lungs, although T. c. cucumerinum migrate more quickly and more synchronously than T. c. sisowi. Typhlocoelum c. sisowi has a shorter expected life-span than T. c. cucumerinum but grows and reaches maturity more quickly than T. c. cucumerinum. Evidence suggests that T. c. cucumerinum has a higher fecundity than T. c. sisowi. These differences in the patterns of migration, growth and development are related not only to differences between the two host species but also to differences intrinsic to the parasites, and serve to provide biological support for considering them as separate sub-species.

ROLE OF FOOD IN TERRITORIALITY AND EGG PRODUCTION OF BUFFLEHEADS (BUCEPHALA ALBEOLA) AND BARROW'S GOLDENEYES (BUCEPHALA ISLANDICA)

The Auk ◽  
2002 ◽  
Vol 119 (4) ◽  
pp. 1075 ◽  
Author(s):  
Jonathan E. Thompson ◽  
C. Davison Ankney
Keyword(s):  
Egg Production ◽  
Bucephala Islandica ◽  
Bucephala Albeola

Feeding activity of ducks in relation to diel emergence of chironomids

1982 ◽  
Vol 60 (6) ◽  
pp. 1383-1387 ◽  
Author(s):  
Kjell Sjöberg ◽  
Kjell Danell
Keyword(s):  
Water Surface ◽  
Food Item ◽  
Feeding Activity ◽  
Emergent Vegetation ◽  
Cold Weather ◽  
Dabbling Ducks ◽  
Entire Surface ◽  
Diving Ducks ◽  
Insect Group

The diel emergence of chironomids, an insect group important as food item for both adult and young ducks, was studied in relation to the feeding activity and behaviour of ducks on a northern Swedish lake (66°3′ N, 23°46′ E) during 1975–1978. Emergence and swarming activity of chironomids peaked between 0800 and 1200. Emergence occurred even on windy days, but almost completely ceased during periods of rainy and cold weather. Swarming occurred mainly around 1000 on warm days with little or no wind. During such occasions, a large number of chironomids were observed over the entire surface of the lake. Dabbling ducks fed throughout a 24-h period, but peak feeding coincided with periods of chironomid emergence. Surface feeding by both dabbling and diving ducks on chironomid imagines present on the water surface and on emergent vegetation increased during these periods of chironomid emergence.

scholarly journals Nonbreeding Duck Use at Central Flyway National Wildlife Refuges

2018 ◽  
Vol 9 (1) ◽  
pp. 45-64 ◽  
Author(s):  
Kent Andersson ◽  
Craig A. Davis ◽  
Grant Harris ◽  
David A. Haukos
Keyword(s):  
New Mexico ◽  
Dabbling Ducks ◽  
National Wildlife Refuge ◽  
Population Total ◽  
Diving Ducks ◽  
Wildlife Refuge ◽  
National Wildlife Refuge System ◽  
Central Flyway ◽  
The U.S

Abstract Within the U.S. portion of the Central Flyway, the U.S. Fish and Wildlife Service manages waterfowl on numerous individual units (i.e., Refuges) within the National Wildlife Refuge System. Presently, the extent of waterfowl use that Refuges receive and the contribution of Refuges to waterfowl populations (i.e., the proportion of the Central Flyway population registered at each Refuge) remain unassessed. Such an evaluation would help determine to what extent Refuges support waterfowl relative to stated targets, aid in identifying species requiring management attention, inform management targets, and improve fiscal efficiencies. Using historic monitoring data (1954–2008), we performed this assessment for 23 Refuges in Texas, New Mexico, Oklahoma, Kansas, and Nebraska during migration and wintering months (October–March). We examined six dabbling ducks and two diving ducks, plus all dabbling ducks and all diving ducks across two periods (long-term [all data] and short-term [last 10 October–March periods]). Individual Refuge use was represented by the sum of monthly duck count averages for October–March. We used two indices of Refuge contribution: peak contribution and January contribution. Peak contribution was the highest monthly count average for each October–March period divided by the indexed population total for the Central Flyway in the corresponding year; January contribution used the January count average divided by the corresponding population index. Generally, Refuges in Kansas, Nebraska, and New Mexico recorded most use and contribution for mallards Anas platyrhynchos. Refuges along the Texas Gulf Coast recorded most use and contribution for other dabbling ducks, with Laguna Atascosa and Aransas (including Matagorda Island) recording most use for diving ducks. The long-term total January contribution of the assessed Refuges to ducks wintering in the Central Flyway was greatest for green-winged teal Anas crecca with 35%; 12–15% for American wigeon Mareca americana, gadwall Mareca strepera, and northern pintail Anas acuta; and 7–8% for mallard and mottled duck Anas fulvigula. Results indicated that the reliance on the National Wildlife Refuge System decreased for these ducks, with evidence suggesting that, for several species, the assessed Refuges may be operating at carrying capacity. Future analyses could be more detailed and informative were Refuges to implement a single consistent survey methodology that incorporated estimations of detection bias in the survey process, while concomitantly recording habitat metrics on and neighboring each Refuge.

scholarly journals The contribution of nasal receptors to the cardiac response to diving in restrained and unrestrained redhead ducks (Aythya americana)

1986 ◽  
Vol 121 (1) ◽  
pp. 227-238 ◽  
Author(s):  
R. A. Furilla ◽  
D. R. Jones
Keyword(s):  
Heart Rate ◽  
Local Anaesthesia ◽  
Cardiac Response ◽  
Dabbling Ducks ◽  
Diving Ducks ◽  
Cardiac Responses ◽  
Aythya Americana ◽  
Dabbling Duck ◽  
Redhead Ducks ◽  
A Minor

In restrained redhead ducks, forced submergence caused heart rate to fall from 100 +/− 3 beats min-1 (mean +/− S.E.M., N = 12) to a stable underwater rate of 35 +/− 4 beats min-1 (N = 12) within 5 s after submergence. Bradycardia was unaffected by breathing oxygen before a dive, but was virtually eliminated by local anaesthesia of the narial region. In contrast, in a dabbling duck (Anas platyrhynchos) bradycardia in short dives was eliminated by breathing oxygen before a dive. In unrestrained diving, on a man-made pond, heart rate in redheads diving voluntarily (y) was related to pre-dive heart rate (x) by the equation y = 76 + 0.29 +/− 0.05x +/− 17 (r2 = 0.71). Chasing, to induce submergence, had variable effects on this relationship. Local anaesthesia of the narial region inhibited voluntary diving but heart rates in chase-induced dives after nasal blockade were significantly higher, by 10–30%, than those obtained from untreated ducks in chase-induced dives. Breathing oxygen before voluntary dives had no apparent effect on heart rate after 2–5 s submergence. Voluntary head submersion by dabbling ducks caused no change in heart rate. We conclude that nasal receptors make only a minor contribution to cardiac responses in unrestrained dives, compared with forced dives, in diving ducks. Furthermore, these results show that little can be learned about cardiac responses in free diving ducks from studies of forced dives in dabblers or divers.

scholarly journals Differences in Plumulaceous Feather Characters of Dabbling and Diving Ducks

The Condor ◽  
2007 ◽  
Vol 109 (1) ◽  
pp. 192-199 ◽  
Author(s):  
Carla J Dove ◽  
Ana Agreda
Keyword(s):  
Principal Components Analysis ◽  
Principal Components ◽  
Dabbling Ducks ◽  
Node Density ◽  
Diving Ducks ◽  
Ecological Requirements ◽  
Components Analysis

Abstract Abstract We examined variation in five microscopic plumulaceous (downy) feather characters of eighteen species of dabbling (Anatini) and diving (Aythyini, Mergini) ducks to quantify the differences between these tribes, and to explain how the plumulaceous feather ultrastructure in ducks may be influenced by different ecological requirements. Over 75% of the variation in feather characters among these ducks was explained by the first two components of a principal components analysis (PCA). Component 1 explained 51% of the variation and was positively correlated with the characters that quantified the number of barbules with expanded nodes and the number of expanded nodes on barbules. The microscopic feather characters of dabbling ducks (Anatini) have triangular-shaped, expanded nodes on most proximal barbules, whereas diving ducks (Aythyini and Mergini) lack expanded nodes on some barbules. Anatini also have a greater density of expanded nodes per barbule, wider nodes, shorter distance between expanded nodes, and longer barbule length. Further analysis of node density across all taxa showed that as dive depths increase, the number of expanded nodes per barbule decreases, and in the deepest divers many of the barbules completely lack expanded nodes. The significantly greater density of expanded nodes in dabbling ducks suggests that the downy nodes may function to trap more air. Diving species have fewer expanded nodes, less buoyant plumage, and are more efficient at foraging in deeper water than dabbling ducks.

Territorial behaviour of the north temperate labrid, Tautogolabrus adspersus

1979 ◽  
Vol 57 (12) ◽  
pp. 2337-2347 ◽  
Author(s):  
Robert A. Pottle ◽  
John M. Green
Keyword(s):  
Territory Size ◽  
Territorial Behaviour ◽  
Intraspecific Aggression ◽  
Tautogolabrus Adspersus ◽  
Interspecific Aggression ◽  
Rocky Substrate ◽  
The North ◽  
Spawning Site ◽  
Peripheral Areas ◽  
Conception Bay

A study of territorial behaviour of the cunner, Tautogolabrus adspersus, was carried out in Conception Bay, Newfoundland, in 1977 and 1978. Cunners that overwinter in a torpid state were active only from May to late October of both years. Large males established territories prior to the midsummer spawning season and territories were defended throughout and after that season. Territory size ranged from 16.1 to 74.3 m2 on rocky substrate at depths of 0.7 to 13 m and did not vary significantly with either the size of the resident fish or the degree of intraspecific aggression it exhibited. Nonterritorial males were generally smaller than territorial males and were vigorously excluded from their territories. Only territorial males exhibited interspecific aggression, which was most frequent toward Pholis gunnellus. Territorial females were present in the peripheral areas of some males' territories and were aggressive toward other females. Tagging indicated that most males and some females defend the same territory from year to year, and that territory size remains relatively constant. The proportions of territorial and nonterritorial fish, of either sex, in the population are unknown. The primary function of territorial behaviour in T. adspersus may be the provision of a spawning site from which potential rivals are excluded.

Differences in flight and heart muscle mass among geese, dabbling ducks, and diving ducks relative to habitat use

1988 ◽  
Vol 66 (9) ◽  
pp. 2024-2028 ◽  
Author(s):  
R. W. Bethke ◽  
V. G. Thomas
Keyword(s):  
Aspect Ratio ◽  
Relative Mass ◽  
Dabbling Ducks ◽  
Wing Loading ◽  
Wing Form ◽  
Diving Ducks ◽  
Heart Mass ◽  
Heart Size ◽  
Flight Muscles ◽  
The Masses

Geese, dabbling ducks, and diving ducks differ in their ability to take off vertically when initiating flight. For three species of goose (N = 127), five species of dabbling ducks (N = 89), and eight species of diving ducks (N = 128), the masses of pectoralis, supracoracoideus, and heart muscles, and two indices of wing form (wing loading and aspect ratio) were measured. Differences in take-off ability among the groups were associated with differences in the mass, i.e., the potential power output, of the flight and heart muscles, and in wing form. Dabbling ducks had the greatest relative mass of flight muscles (p < 0.0001), lowest wing loading, and highest aspect ratio, and elevate almost vertically from the water's surface when taking off. Conversely, diving ducks had the smallest flight muscles, highest wing loading, and smallest aspect ratio, and begin flight by running over the surface of the water to gain sufficient forward velocity. Geese were intermediate between dabbling ducks and diving ducks for these three characteristics. Diving ducks however, had the largest heart mass of the three groups (p < 0.0024). Among diving ducks, heart size increased with the foraging depth of each species. It is suggested that heart size in diving ducks reflects a response to diving superimposed upon the demands for flight.

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