Showing papers in "Canadian Journal of Zoology in 1989"
TL;DR: Recordings of underwater vocalizations and behavioural observations were collected from 16 photographically identified resident pods of killer whales off Vancouver Island, British Columbia, during 1978–1983 and no call type was correlated exclusively with any behaviour or circumstance that could be identifie...
Abstract: Recordings of underwater vocalizations and behavioural observations were collected from 16 photographically identified resident pods of killer whales (Orcinus orca) off Vancouver Island, British Columbia, during 1978–1983. Vocalizations recorded during 43 days spent with three representative pods were analyzed for each of five activity states: foraging, travelling, group-resting, socializing, and beach-rubbing. The whales produced three types of sounds that were assumed to be social signals: discrete calls, variable calls, and aberrant calls. Discrete calls dominated vocalization in most contexts. An increase in production of variable and aberrant calls was observed during socializing and beach-rubbing activities. Each resident pod had a group-specific repertoire of 7–17 discrete call types (mean = 10.7) that was consistent over a number of years. The relative use of different calls varied with activity, but no call type was correlated exclusively with any behaviour or circumstance that could be identifie...
362 citations
TL;DR: A severe hypoxia developed with the cessation of breathing in deep anaesthesia, accompanied by a rise in blood and adrenaline concentration, and a fall in blood pH, in resting rainbow trout fitted with chronic catheters in the dorsal aorta.
Abstract: Some physiological aspects of five fish anaesthetics in rainbow trout were investigated. The effects of benzocaine, 2-phenoxyethanol, MS-222 (Sandoz), metomidate, and carbon dioxide gas (CO2) on ac...
330 citations
TL;DR: Evidence for the occurrence and intensity of conspecific nest parasitism within both the self-feeders and the birds that feed their young is reviewed, suggesting that it is produced by a fundamental dichotomy in selection pressure for defense against Conspecific parasites.
Abstract: Conspecific nest parasitism is much more common in birds that have self-feeding young than in those with parentally fed young. We review evidence for this pattern and suggest that it is produced by...
231 citations
TL;DR: It is confirmed that interspecific divergence in morphological, meristic, and morphometrical features is unusually weak in Pseudocalanus, and biochemical evidence obtained, obtained for six of the seven species, supports the taxonomy proposed here.
Abstract: Apparent lack of interspecific morphological differentiation and potential co-occurrence of cryptic species have plagued the scientific study of marine planktonic copepods of the genus Pseudocalanus This taxonomic analysis of Pseudocalanus, based on material collected throughout the geographical range of the genus, establishes the identities of the previously described species and provides evidence for the existence of three previously unrecognized species As proposed here, the genus now contains seven species It is confirmed that interspecific divergence in morphological, meristic, and morphometrical features is unusually weak in Pseudocalanus Nevertheless, biochemical evidence (presented elsewhere), obtained for six of the seven species, supports the taxonomy proposed here At least two species of Pseudocalanus were found at most localities within the geographical range of the genus; co-occurrences of three species were common, and the ranges of four species overlap in the eastern Bering Sea and coa
199 citations
TL;DR: Remote time–depth recorders were deployed on six gravid leatherbacks nesting on Sandy Point, St Croix, and distinct diel periodicity was observed in dive behavior; submergence intervals were longest at dawn, declined throughout the day, and were shortest at dusk.
Abstract: Remote time–depth recorders (TDR) were deployed on six gravid leatherbacks nesting on Sandy Point, St Croix Dive behavior was monitored continuously for each turtle during internesting intervals
181 citations
TL;DR: The diving patterns of 10 adult female California sea lions were examined during the summer breeding season on San Miguel Island, California, in 1982 and 1983 using time–depth recorders to suggest cost–benefit considerations based on prey availability and encounter rate may be more important than physiological limits in shaping the foraging patterns of Zalophus.
Abstract: The diving patterns of 10 adult female California sea lions (Zalophus californianus) were examined during the summer breeding season on San Miguel Island, California, in 1982 and 1983 using time–de...
178 citations
TL;DR: Flight initiation distance in response to a motorized model predator (a cat) increased as distance to refuge increased, and could not be attributed to any effect of distance to Refuge on vigilance.
Abstract: Gray squirrels (Sciurus carolinensis) typically run to the nearest tree to escape from predators they encounter while foraging on the ground. As the risk of capture increases with distance from the...
175 citations
TL;DR: Evidence is presented for additional involvement of both blood acid–base status and circulating catecholamines in controlling ventilation in fishes, where arterial oxygen content traditionally has been considered the predominant factor controlling ventilation.
Abstract: Recent developments pertaining to the control and coordination of gas transfer in fishes have been reviewed. Gill ventilatory water flow can markedly affect blood respiratory and blood acid–base status. Although arterial oxygen content traditionally has been considered the predominant factor controlling ventilation, we present evidence for additional involvement of both blood acid–base status and circulating catecholamines. An analysis of the independent effects of blood oxygen content, acid–base status, and catecholamines in controlling ventilation is confounded by the interrelationships among these variables. It is likely, however, that each factor is involved to some extent in ventilatory control in fishes. Blood oxygen transport is affected by the carrying capacity of the blood and red blood cell chemical status. Blood oxygen-carrying capacity is increased during periods of stress by adrenergic release of red blood cells from the spleen. Concurrently, adrenergic stimulation of red blood cell Na+–H+ ex...
165 citations
TL;DR: It is reported that female northern elephant seals (Mirounga angustirostris) dive deeply and continuously during the first 1–3 weeks at sea following lactation and is maintained for the entire 2½-month period at sea.
Abstract: An earlier study showed that female northern elephant seals (Mirounga angustirostris) dive deeply and continuously during the first 1–3 weeks at sea following lactation. We report that this dive pa...
142 citations
TL;DR: Tracks of marten (Martes americana), lynx (Felis lynx), red fox (Vulpes vulpes), ermine (Mustela erminea), snowshoe hare (Lepus americanus), and red squirrel (Tamiasciurus hudsonicus) were censused.
Abstract: Tracks of marten (Martes americana), lynx (Felis lynx), red fox (Vulpes vulpes), ermine (Mustela erminea), snowshoe hare (Lepus americanus), and red squirrel (Tamiasciurus hudsonicus) were censused...
142 citations
TL;DR: The pancreatic peptide hormones insulin, glucagon, and glucagon-like peptide (GLP) modify metabolic flux in rainbow trout liver and quantifies the plasma titres in this study.
Abstract: The pancreatic peptide hormones insulin, glucagon, and glucagon-like peptide (GLP) modify metabolic flux in rainbow trout liver. This study quantifies the plasma titres of these peptide hormones us...
TL;DR: Matrix comparison tests (i.e., Mantel's test or quadratic assignment) are employed with increasing frequency to measure the concordance between genetic, behavioural, morphological, ecological, and ...
Abstract: Matrix comparison tests (i.e., Mantel's test or quadratic assignment) are employed with increasing frequency to measure the concordance between genetic, behavioural, morphological, ecological, and ...
TL;DR: Nest predation rates in the early part of the breeding season were positively related to indices of fox, American crow (Corvus brachyrhynchos), and badger activity, and Predation rates on early-season ne...
Abstract: We followed 3094 upland nests of several species of ducks. Clutches in most nests were lost to predation. We related daily nest predation rates to indices of activity of eight egg-eating predators,...
TL;DR: Resource partitioning between bobcats and coyotes was investigated in eastern Maine during 1979–1984, when colonizing populations of coyotes were rapidly expanding, to investigate activity patterns, spatial relationships, and habitat use.
Abstract: Resource partitioning between bobcats (Felis rufus) and coyotes (Canis latrans) was investigated in eastern Maine during 1979–1984, when colonizing populations of coyotes were rapidly expanding. A total of 2615 radio locations of 10 resident bobcats and 6 resident coyotes were used to investigate activity patterns, spatial relationships, and habitat use. The daily distribution of activity by both species was similar during all seasons, and neighboring bobcat–coyote home ranges overlapped. Simultaneous locations of eight sympatric bobcat–coyote pairs (≥ 10% home range overlap) indicated an apparent lack of attraction or avoidance between neighboring heterospecifics. Bobcats preferred hardwood stands during all seasons (P < 0.05), and occupied softwood-dominated stands less than expected (P < 0.05) during autumn and winter. Coyote habitat use was less consistent, and indices of habitat-use overlap with bobcats varied from 0.60 during autumn to 1.00 during winter. Seasonal indices of diet diversity, based on...
TL;DR: Sperm whales, Physeter macrocephalus, were tracked by means of a recording depth sounder in the waters off the Galapagos Islands, and usually started to make regular clicks when 150–300 m deep, which is approximately the depth of the oxygen minimum.
Abstract: Sperm whales, Physeter macrocephalus, were tracked by means of a recording depth sounder in the waters off the Galapagos Islands. At depths of less than 300 m the whales generally dived nearly vertically at 60–100 m/min. At greater depths their descents were usually slower. Between February and April 1985, they dived to about 420 m, which is approximately the depth of the oxygen minimum. In 1987, a year of warmer water temperatures, they usually dived about 70 m shallower. There was no apparent diurnal variation in dive depths. None of the whales tracked dived to the ocean floor. Whales dived for about 40 min, followed by 10 min at the surface. Sperm whales usually started to make regular clicks when 150–300 m deep. Young calves appeared not to make prolonged deep dives. Our results are generally consistent with other direct information on the diving behaviour of relatively undisturbed sperm whales, but often conflict with results obtained using sonar for sperm whales being chased by whale catchers.
TL;DR: Cladistic analysis of behavioural interactions during a series of female choice trials revealed three groups of reproductively unsuccessful males in a population of anadromous Gasterosteus aculeatus: inactive losers, active losers, and fighting losers.
Abstract: Cladistic analysis of behavioural interactions during a series of female choice trials revealed three groups of reproductively unsuccessful males in a population of anadromous Gasterosteus aculeatu...
TL;DR: This study provides the first measurements of daily water flux in free-ranging bats during pregnancy and lactation using the wash-out rate of tritiated water from the body water pool to calculate dailyWater flux in 10 pregnant and 14 lactating little brown bats (Myotis lucifugus).
Abstract: This study provides the first measurements of daily water flux in free-ranging bats during pregnancy and lactation. We used the wash-out rate of tritiated water from the body water pool to calculate daily water flux in 10 pregnant and 14 lactating little brown bats (Myotis lucifugus). Average water influx was 6.16 ± 0.47 (SE) mL/day during pregnancy and 6.91 ± 0.37 mL/day during lactation; average efflux was 6.27 ± 0.44 and 7.07 ± 0.36 mL/day during pregnancy and lactation, respectively. Using data from the literature, we partitioned daily flux into major components. Our calculations indicated that most (> 62%) water influx was preformed water in the insect diet. Drinking water represented 23–26% of daily influx. Although previous studies indicated that evaporative losses greatly exceeded urinary losses in laboratory-maintained M. lucifugus, urinary and evaporative losses were comparable in our free-ranging bats. Urinary losses represented 46% of water efflux during pregnancy and 35% during lactation. Ove...
TL;DR: The topography of the basin, prevailing summer currents, and orientation of transition zones from mixed to stratified water all combine to facilitate accumulation of copepods from the Scotian Shelf and Gulf of Maine in the centra...
Abstract: Temperature, salinity, density of Zooplankton patches, and the abundance of right whales (Eubalaena glacialis glacialis) were measured concurrently during summer and autumn of 1983 and 1984 over th...
TL;DR: No differences were found in relative prey importance between adult porpoises of different reproductive conditions, but lactating females ingested more fish and had a significantly higher total caloric intake than nonlactating females or mature males.
Abstract: We examined contents from stomachs of 127 harbour porpoises (Phocoena phocoena) caught in groundfish gill nets in the western Bay of Fundy during June to September, 1985–1987. Relative importance of prey species was assessed using both numerical and caloric measures. Atlantic herring (Clupea harengus) was the most important prey species, contributing 80% of the total caloric intake, with some spatial and temporal variation. Silver hake (Merluccius bilinearis) and Atlantic cod (Gadus morhua) were also important, but together comprised only 17% of the total caloric intake. No differences were found in relative prey importance between adult porpoises of different reproductive conditions, but lactating females ingested more fish and had a significantly higher total caloric intake than nonlactating females or mature males. The diet of porpoises collected from the same area in 1969–1972 consisted of a higher proportion of pelagic prey species and a lower proportion of demersal species. This may be attributed to...
TL;DR: A detailed electron microscopic study spanning the period of nymphal attachment to the host to determine whether B. burgdorferi invades the salivary acini and ducts of Lyme disease spirochete Borrelia burgdorFERi is employed.
Abstract: The route followed by the Lyme disease spirochete Borrelia burgdorferi as it passes from vector to host has been the subject of controversy over whether the spirochete is transmitted through the saliva of the tick or through regurgitation during feeding. In the event that the spirochete's presence in the salivary tissues is transient we employed a detailed electron microscopic study spanning the period of nymphal attachment to the host to determine whether B. burgdorferi invades the salivary acini and ducts. In addition we examined other tissues of the tick to determine the route and mode of migration. Two different groups of nymphs were used in this study. After feeding, spirochetes were found in both groups in the gut lumen, epithelium, and within the salivary glands and ducts. Borrelia is able to pass both inter- and intra-cellularly through these tissues. In one group of unfed nymphs Borrelia was limited to the gut lumen, whereas the second group demonstrated a disseminated infection. This difference ...
TL;DR: The results suggest that bearded seals may be relatively sedentary and that geographically different vocal repertoires may be characteristic of discrete breeding stocks.
Abstract: The underwater vocalizations of bearded seals (Erignathus barbatus) were recorded between March and June in 1979, 1982, and 1983 at six sites in the Arctic. In total, 970 trills were measured for temporal and spectral characteristics and then classified as one of six types. Trills were narrow in bandwidth and frequency modulated. The repertoires of vocalizing bearded seals varied amongst the six recording sites. Between-site differences in temporal and spectral features, call use, and sequential organization were measured. The results suggest that bearded seals may be relatively sedentary and that geographically different vocal repertoires may be characteristic of discrete breeding stocks. A prominent daily cycle in rate of calling during April and May was found at two sites; rate of calling was higher during the early morning hours (i.e., 03:00–04:00 sun time) than at other times of the day. No distinct temporal cycle occurred during late May and early June. Rate of calling appeared to be negatively corr...
TL;DR: The characteristics of a grizzly bear population in southeastern British Columbia were studied between 1979 and 1986, a period of timber harvest, gas exploration, and outdoor recreation, including grizzly hunting, to investigate the hypothesis that collectively these activities were detrimental to the population.
Abstract: The characteristics of a grizzly bear (Ursus arctos) population in southeastern British Columbia were studied between 1979 and 1986, a period of timber harvest, gas exploration, and outdoor recreat...
TL;DR: Atlantic salmon (Salmo salar) from Little Gull Lake on the Gander River system of central Newfoundland were found to be electrophoretically polymorphic at 5 of 20 protein loci screened.
Abstract: Atlantic salmon (Salmo salar) from Little Gull Lake on the Gander River system of central Newfoundland were found to be electrophoretically polymorphic at 5 of 20 protein loci screened. Four of the...
TL;DR: Coho salmon given intraperitoneal implants of hydrogenated coconut oil alone or coconut oil containing cortisol at 1, 5, or 10 mg/fish exhibited dose-related increases in plasma cortisol levels at day 15, and after 30 days, cortisol levels were significantly higher in the cortisol-implanted groups but there was no dose- related response.
Abstract: Coho salmon given intraperitoneal implants of hydrogenated coconut oil alone or coconut oil containing cortisol at 1, 5, or 10 mg/fish exhibited dose-related increases in plasma cortisol levels at day 15. After 30 days, plasma cortisol levels were significantly higher in the cortisol-implanted groups but there was no dose-related response. Plasma T3 levels were lowered in cortisol-treated fish, but plasma T4 levels were not consistently affected. Plasma glucose levels were significantly higher in the group treated with cortisol at 10 mg/fish than in the controls on both sampling days, whereas liver glycogen content and hepatosomatic index were significantly lower in the cortisol-treated groups at day 30 but not at day 15. Plasma protein levels were not significantly different between treatments at either sampling time. The splenosomatic indices were not significantly different in the three treatment groups at day 15, but at day 30 the values in the 5 and 10 mg/fish cortisol-treated groups were significant...
TL;DR: Between 1985 and 1987, 49 283 locations and 79 101 sets of activity data were obtained for 34 adult female caribou of the Porcupine and Central Arctic herds using satelli...
Abstract: Between 1985 and 1987, 49 283 locations and 79 101 sets of activity data were obtained for 34 adult female caribou (Rangifer tarandus granti) of the Porcupine and Central Arctic herds using satelli...
TL;DR: Morphofunctional parameters were studied during adaptation of rainbow trout to different ionic environments: Strasbourg tap water, ion-poor water, and artificial seawater.
Abstract: Morphofunctional parameters were studied during adaptation of rainbow trout (Oncorhynchus mykiss) to different ionic environments: Strasbourg tap water, ion-poor water, and artificial seawater. The...
TL;DR: It is found that during courtship the male sang accented-ending songs on those infrequent occasions when he did sing in the immediate presence of his female, regardless of her location and the presence or abse...
Abstract: Males of many wood warbler (Parulinae) species use different song types in different contexts, yet the exact functions of the two main song type categories remain unclear. We studied the use of songs by both experimental (males whose mate had been removed from the territory) and control male Chestnut-sided Warblers (Dendroica pensylvanica) during the dawn hour and midmorning throughout the breeding season. Unpaired males sang more accented-ending songs and fewer unaccented-ending songs than paired males during all observation periods. Accented-ending songs appeared to be used primarily in the absence of intrasexual stimuli, and the percentage of unaccented-ending songs that was used during the nesting cycle appeared to fluctuate directly with the intensity of defense by the male of both his female and his territory. During courtship the male sang accented-ending songs on those infrequent occasions when he did sing in the immediate presence of his female, regardless of her location and the presence or abse...
TL;DR: Overwintered females of species from temporary habitats lived longer than those from more permanent habitats, and, concomitantly, are able to spread reproduction over several ponds, suggesting that values observed are good measures of reproductive potential.
Abstract: Reproductive traits, diapause, and wing dimorphism of four pond skater species occurring in central Alberta, Canada, are explained as adaptive responses to a complex of habitat features. Species using temporary habitats had greater fecundity, but habitat permanence alone was a poor predictor of reproductive longevity, preoviposition period, or reproductive rate. Fecundity and longevity were significantly lower and more variable in direct than in diapaused breeders. There was no geographical or annual variation in fecundity, suggesting that values observed are good measures of reproductive potential. Overwintered females of species from temporary habitats (Gerris buenoi and Limnoporus dissortis) lived longer than those from more permanent habitats (G. comatus and G. pingreensis), and, concomitantly, are able to spread reproduction over several ponds. Proportion of summer-generation bugs breeding without diapause was inversely related to habitat permanence for the Gerris species, but few nondiapause breeder...
TL;DR: Rainbow trout fitted with dorsal aortic cannulae were exposed in a flow-through soft water system to three acidities and two concentrations of Ca, and blood acidosis was a combination of respiratory acidosis and metabolic acidosis.
Abstract: Rainbow trout (Salmo gairdneri) fitted with dorsal aortic cannulae were exposed in a flow-through soft water system to three acidities (pH 5.2, 4.8, or 4.4) and two concentrations of Ca (45 or 410 μequiv.∙L−1), in the presence (105 μg∙L−1) or absence of Al. Blood was sampled for respiratory gases, ions, metabolites, and hematology before and at 4, 18, 28, 42, and 66 h exposure. Two toxic mechanisms of Al and acidity were seen: (i) ionoregulatory toxicity, which was caused by Al at pH 5.2 and 4.8 and by acidity at pH 4.4, and (ii) respiratory toxicity, which was caused solely by Al, and was greatest at higher pH. Ionoregulatory toxicity involved decreases in plasma Na+ and Cl−, red cell swelling, and hemoconcentration. Respiratory toxicity involved reduced blood oxygen tension, elevated blood carbon dioxide tension, and increases in blood lactate. Blood acidosis was a combination of respiratory acidosis (due to CO2 accumulation in the blood; higher pH exposures) and metabolic acidosis (probably due to diff...
TL;DR: Formation of an acid gill water boundary layer as a result of CO2 excretion will trap NH3 as and enhance ammonia transfer and alkalinize water as it passes over the gills.
Abstract: The pH of plasma is midway between the pK of the and reactions. Carbon dioxide excretion across the gill acidifies the water, as CO2 hydrates to form and H+ ions. The hydration reaction is catalyze...