Changes in activity patterns, agonistic behavior, and territoriality of black ducks (Anas rubripes) during the breeding season in a Nova Scotia tidal marsh

1978 ◽  
Vol 56 (8) ◽  
pp. 1773-1785 ◽  
Author(s):  
Norman R. Seymour ◽  
Rodger D. Titman
Keyword(s):  
Nova Scotia ◽  
Breeding Season ◽  
Activity Patterns ◽  
Quantitative Description ◽  
Egg Laying ◽  
Spatial Displacement ◽  
Lawrence Estuary ◽  
Qualitative And Quantitative ◽  
Males And Females ◽  
St Lawrence Estuary

Observations of marked wild black ducks provided a qualitative and quantitative description of hostile interactions between pairs throughout the breeding season. This study was carried out on a tidal estuary on the St. Lawrence estuary shore of Nova Scotia from 1972 to 1974. Interactions occurred first on the communal part of the marsh and later on territories.Territories corresponded to tidal ponds (0.16–3.8 ha) at the marsh periphery and were established only after pairs were on the marsh 30–40 days. Territories were established approximately 5 days before egg laying began and females were responsible for their location. Females spent approximately 45 days on the territory and males stayed 27–32 days. Males remained almost continuously on territories during the prelaying and laying periods but left both females and territories during midincubation.The activity of males and females of pairs was analysed and compared according to three activities: foraging, loafing, and hostility. Females foraged at a faster rate and for longer durations than their mates in both the preterritorial and territorial periods. Hostility by territorial males toward intruding pairs provided seclusion for resident pairs. Changes in the form and intensity of hostility led to the spatial displacement of pairs. The pursuit flight by males was the main mechanism in the establishment and maintenance of territories.

Forced copulation in sympatric American black ducks and mallards in Nova Scotia

1990 ◽  
Vol 68 (8) ◽  
pp. 1691-1696 ◽  
Author(s):  
N. R. Seymour
Keyword(s):  
Nova Scotia ◽  
Breeding Season ◽  
Breeding Period ◽  
Lawrence Estuary ◽  
Qualitative And Quantitative ◽  
Black Duck ◽  
Forced Copulation ◽  
American Black ◽  
St Lawrence Estuary

Observations of primarily identifiable wild black ducks and mallards provided qualitative and quantitative descriptions of interactions within and between intraspecific, interspecific, and heterospecific pairs throughout the breeding season. The study was carried out in a watershed on the St. Lawrence estuary shore of Nova Scotia from 1972 to 1988. Attempted forced copulation and forced pair copulation were rare among black ducks at any time throughout the breeding period. Only two apparently successful forced copulations were observed. Territorial males chased both female black ducks and mallards, and these chases appeared motivated by hostility. Males that had left their mates/territories did not attempt forced copulation with other females. Females sometimes avoided strange males, particularly when they returned to territories from their nests. Paired males rarely approached females with broods. Male mallards chased both female mallards and black ducks, and did not appear to discriminate between species when attempting forced copulation. Male mallards were more persistent and vigorous in their chases than black ducks, and they attempted forced copulation, whether with black ducks or mallards, more frequently than male black ducks did. Apparently successful forced copulation between a male mallard and female black duck occurred on three occasions.

Aerial pursuit flights in the shoveler

1974 ◽  
Vol 52 (12) ◽  
pp. 1473-1480 ◽  
Author(s):  
Norman R. Seymour
Keyword(s):  
Breeding Season ◽  
Quantitative Description ◽  
Wild Birds ◽  
Flight Behavior ◽  
Territorial Defense ◽  
Qualitative And Quantitative ◽  
Active Mechanism ◽  
Seasonal Basis ◽  
Males And Females

Analysis of 266 pursuit flights of wild birds provided a qualitative and quantitative description of aspects of this phenomenon. Flight behavior and frequency were analyzed for the general prelaying, laying, incubation, and renesting periods.Flight behavior of pursued males and females and that of the pursuing male varied little throughout the breeding season. No difference was detected on a daily basis.Flight frequency was greatest during the morning (0500 to 1000 h) period throughout the season. On a seasonal basis, frequency was greatest during territory establishment and declined after general incubation began. Another peak of activity occurred during the renesting period. Frequency during all periods reflected the number of non-territorial pairs interacting with territorial pairs.Attempted rape and associated flight was rare, with most flights apparently resulting from hostility associated with territorial defense. The pursuer was invariably a territorial male.The pursuit flight functioned in the establishment and maintenance of territories and was the major active mechanism in the spacing of breeding pairs.

scholarly journals Do Barrow's Goldeneyes, Bucephala islandica, Breed South of the St. Lawrence Estuary in the Gaspé Peninsula, Eastern Canada?

2010 ◽  
Vol 124 (2) ◽  
pp. 179
Author(s):  
Jean-François Ouellet ◽  
Pierre Fradette ◽  
Isabel Blouin
Keyword(s):  
North America ◽  
Breeding Season ◽  
Breeding Habitat ◽  
Eastern North America ◽  
Eastern Canada ◽  
Lawrence Estuary ◽  
North Shore ◽  
The North ◽  
Bucephala Islandica ◽  
St Lawrence Estuary

We report the first observations of Barrow's Goldeneyes south of the St. Lawrence estuary in typical breeding habitat during the breeding season. Until recently, the confirmed breeding locations for the species in Eastern North America were all located on the north shore of the Estuary and Gulf of St. Lawrence.

Habitat segregation among the age groups of Gasterosteus aculeatus (Pisces: Gasterosteidae) in the middle St. Lawrence estuary, Canada

1990 ◽  
Vol 68 (6) ◽  
pp. 1202-1208 ◽  
Author(s):  
Paul Picard Jr. ◽  
Julian J. Dodson ◽  
Gérard J. FitzGerald
Keyword(s):  
Breeding Season ◽  
Gasterosteus Aculeatus ◽  
Age Groups ◽  
Minimum Size ◽  
Spawning Period ◽  
Lawrence Estuary ◽  
Age Related ◽  
Tidal Rivers ◽  
Marsh Pools ◽  
St Lawrence Estuary

Previous studies of migratory populations of sticklebacks (Pisces: Gasterosteidae) have been exclusively limited to their biology on the spawning grounds during the spring breeding season. In 1985 and 1986, we studied the ecology of the threespine stickleback (Gasterosteus aculeatus) in three subhabitats of the middle St. Lawrence estuary before, during, and after the breeding season: (i) the open waters of the estuary, (ii) a series of intertidal salt marsh pools, and (iii) two tidal rivers (Rivière des Vases and Rivière Trois-Pistoles). In spring, our catch data in the various subhabitats showed that adults moved from the open waters of the estuary towards the tidal rivers and tide pools. Catches of adults in all subhabitats subsequently declined, whereas the young of the year (age 0+) became increasingly abundant. In this area, G. aculeatus live for 2 years and are physiologically capable of breeding during their first summer as adults. However, we found age-related differences in habitat use between the two adult year classes. Age 1+ fish were never more abundant than age 2+ fish in Rivière des Vases, in the tide pools, and in the open waters of the estuary, whereas age 1+ fish were more abundant than age 2+ fish in Rivière Trois-Pistoles. Throughout the breeding season, gonadosomatic indices of female G. aculeatus were the same for the two age groups. Total lengths of age 0+ fish captured in the various subhabitats suggest that the major spawning period is limited to May and June. Age 0+ fish do not leave the tide pools for the open waters of the estuary before having attained a certain minimum size.

Breeding-season habitat use by sticklebacks (Pisces: Gasterosteidae) at Isle Verte, Quebec

1989 ◽  
Vol 67 (9) ◽  
pp. 2126-2130 ◽  
Author(s):  
F. G. Whoriskey ◽  
G. J. Fitzgerald
Keyword(s):  
Salt Marsh ◽  
Habitat Use ◽  
Breeding Season ◽  
Habitat Choice ◽  
Lawrence Estuary ◽  
Use Patterns ◽  
Tidal Salt Marsh ◽  
Large Numbers ◽  
Marsh Pools ◽  
St Lawrence Estuary

We examined habitat use patterns of three species of sticklebacks as they moved from the St. Lawrence estuary into tidal salt marsh pools to breed. All three species apparently avoided pools that dried out and settled more often in pools that retained their water. Habitat choice by immigrants was not influenced by either the presence of the most aggressive species or by resident fish density. Movements of fish into the marsh and densities of fish in the pools peaked on the first days of the approximately 7-day flooding cycles, and declined thereafter. Thus, large numbers of fish moved away from these pools after initially settling in them, but the reason for this and the subsequent fate of the fish is unknown.

Erratum: Response of the sea urchin, Strongylocentrotus droebachiensis, to reduced salinities: importance of size, acclimation, and interpopulation differences

1984 ◽  
Vol 62 (11) ◽  
pp. 2352-2352 ◽  
Author(s):  
John H. Himmelman ◽  
Helga Guderley ◽  
Gilles Vignault ◽  
Guy Drouin ◽  
Peter G. Wells
Keyword(s):  
Nova Scotia ◽  
Strongylocentrotus Droebachiensis ◽  
Test Diameter ◽  
Lawrence Estuary ◽  
Stress Acclimation ◽  
Hypoosmotic Stress ◽  
Size Groups ◽  
Percentage Weight ◽  
St Lawrence Estuary ◽  
Neuromuscular Coordination

Weight change, mortality, and neuromuscular coordination, as measured by righting time, were used to evaluate the resistance of Strongylocentrotus droebachiensis to hypoosmotic stress. Acclimation to a salinity of 24 or 25‰ decreased the righting time of urchins after 96 h of hypoosmotic stress. The effect of acclimation was the same for four size groups of urchins (10–15, 20–25, 34–37, and 50–60 mm in test diameter). A comparison of urchins from the St. Lawrence Estuary and from Nova Scotia, both acclimated to 24‰, showed that for the three larger size classes, the salinity at which there was a significant increase in righting time was lower for urchins from an estuarine environment than for urchins from the oceanic environment. The percentage weight gain following hypoosmotic stress increased with decreasing urchin size. For small urchins the increase was less marked after acclimation to 24‰. The mortality rates following these experiments showed that acclimation to a reduced salinity increased the tolerance to hypoosmotic stress, that urchins from the St. Lawrence Estuary were better able to withstand low salinities than urchins from Nova Scotia, and that small urchins were more sensitive to osmotic stress than large urchins. The latter was confirmed in a field experiment in which four size groups of urchins were kept in cages at a location exposed to periodic decreases in surface salinities.

On sex-specific foraging behaviour in the Willow Warbler, Phylloscopus trochilus

1991 ◽  
Vol 69 (2) ◽  
pp. 462-470 ◽  
Author(s):  
K. G. Kenneth Nyström
Keyword(s):  
Breeding Season ◽  
Foraging Behaviour ◽  
Wing Length ◽  
Wing Shape ◽  
Egg Laying ◽  
Willow Warbler ◽  
Field Station ◽  
Brood Rearing ◽  
Phylloscopus Trochilus ◽  
Males And Females

The foraging behaviour of Willow Warblers (Phylloscopus trochilus) in relation to the availability of their insect prey was studied at the Tovetorp Field Station and at the Royal Park of Djurgården, Stockholm, Sweden, from 1985 through 1989. The numbers and types of arthropods available to Willow Warblers fluctuated throughout the breeding season. In general, most arthropods were found on the underside of the leaves. Males spent more time gleaning and less time hovering and fly catching when preying chiefly on aphid nymphs then when foraging on other arthropods on birch before budbreak. They performed more fly-catching behaviour and tended to forage in taller trees than did females. Dissimilarities in foraging behaviour between the sexes were attributed to differences in wing length and wing shape. Because females are smaller and have less pointed wings they are better adapted for hovering than males. Consequently, females were better at capturing prey on the underside of birch and willow leaves, which was abundant during the egg-laying and brood-rearing periods. Thus, in birch and willow, females hovered more frequently than males, but there was no difference between males and females foraging in spruce, pine, and oak.

Barnacle recruitment on ice-scoured shores in eastern Canada

2008 ◽  
Vol 88 (2) ◽  
pp. 289-291 ◽  
Author(s):  
Elizabeth A. MacPherson ◽  
Ricardo Scrosati ◽  
Patrick Chareka
Keyword(s):  
Nova Scotia ◽  
Sea Ice ◽  
Structural Complexity ◽  
Semibalanus Balanoides ◽  
Eastern Canada ◽  
Lawrence Estuary ◽  
Selective Pressures ◽  
Larval Behaviour ◽  
Recruitment Patterns ◽  
St Lawrence Estuary

Previous observations in the St Lawrence Estuary (eastern Canada) suggested that larvae of intertidal barnacles (Semibalanus balanoides) would settle almost exclusively inside crevices on shores that are scoured by sea ice every winter. It was suggested that the strong ice scour in winter on that coast (which removes organisms outside of crevices) would select for such a larval behaviour. We tested the generality of this pattern by sampling other ice-scoured shores within the Gulf of St Lawrence system. In particular, we surveyed a shore in Nova Scotia where exposed habitats (subjected to strong ice scour in winter) are interspersed with sheltered habitats (which suffer milder ice scour). Such a topographical complexity might allow for the coastal larval pool to contain a proportion of larvae that have no particular settlement preference for crevices, as selective pressures for such a behaviour would be minimal in ice-sheltered habitats. Consistently with this notion, barnacle recruits (which appear after the winter ice melts) occurred abundantly both inside and outside of crevices across the shore in the spring seasons of 2005 and 2006. Average recruit density on rocky surfaces ranged between 337 and 588 recruits dm−2, depending on the habitat. It is therefore possible that barnacle recruitment patterns on ice-scoured shores may be affected indirectly by the structural complexity of the coast.

Response of the sea urchin, Strongylocentrotus droebachiensis, to reduced salinities: importance of size, acclimation, and interpopulation differences

1984 ◽  
Vol 62 (6) ◽  
pp. 1015-1021 ◽  
Author(s):  
John H. Himmelman ◽  
Helga Guderley ◽  
Gilles Vignault ◽  
Guy Drouin ◽  
Peter G. Wells
Keyword(s):  
Nova Scotia ◽  
Strongylocentrotus Droebachiensis ◽  
Test Diameter ◽  
Lawrence Estuary ◽  
Stress Acclimation ◽  
Hypoosmotic Stress ◽  
Size Groups ◽  
Percentage Weight ◽  
St Lawrence Estuary ◽  
Neuromuscular Coordination

Weight change, mortality, and neuromuscular coordination, as measured by righting time, were used to evaluate the resistance of Strongylocentrotus droebachiensis to hypoosmotic stress. Acclimation to a salinity of 24 or 25‰ decreased the righting time of urchins after 96 h of hypoosmotic stress. The effect of acclimation was the same for four size groups of urchins (10–15, 20–25, 34–37, and 50–60 mm in test diameter). A comparison of urchins from the St. Lawrence Estuary and from Nova Scotia, both acclimated to 24‰, showed that for the three larger size classes, the salinity at which there was a significant increase in righting time was lower for urchins from an estuarine environment than for urchins from the oceanic environment. The percentage weight gain following hypoosmotic stress increased with decreasing urchin size. For small urchins the increase was less marked after acclimation to 24‰. The mortality rates following these experiments showed that acclimation to a reduced salinity increased the tolerance to hypoosmotic stress, that urchins from the St. Lawrence Estuary were better able to withstand low salinities than urchins from Nova Scotia, and that small urchins were more sensitive to osmotic stress than large urchins. The latter was confirmed in a field experiment in which four size groups of urchins were kept in cages at a location exposed to periodic decreases in surface salinities.

Croissance de la plie rouge (Pseudopleuronectes americanus) de l'estuaire maritime du Saint-Laurent

1985 ◽  
Vol 63 (7) ◽  
pp. 1610-1616 ◽  
Author(s):  
Robert Vaillancourt ◽  
Jean-Claude F. Brêthes ◽  
Gaston Desrosiers
Keyword(s):  
Linear Growth ◽  
Sampling Period ◽  
The Other ◽  
Pseudopleuronectes Americanus ◽  
Spawning Period ◽  
Lawrence Estuary ◽  
Growth Equations ◽  
South Shore ◽  
Males And Females ◽  
St Lawrence Estuary

A study on the growth in size and weight of the Winter Flounder, Pseudopleuronectes americanus (Walbaum), was conducted from samples collected during the summers of 1979 and 1980, in the bay of Saint-Fabien-sur-Mer (Québec) on the south shore of the Lower St. Lawrence Estuary. Age was determined by otolith readings and length–weight relationships were calculated. Linear growth equations were not statistically different for males and females. On the other hand, weight was found to be higher for females than for males of equal sizes. This relationship also varies with the sampling period, and a substantial weight increase follows the spawning period. The growth of P. americanus is slower in the estuary than in more southern areas, while the weights at equal sizes are higher. These results reflect the severe environmental conditions, which necessitate a large accumulation of food energy by the fish as reserves, to the detriment of growth.

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