Climate change models often assume similar responses to temperatures acrossthe range of a species, but local adaptation or phenotypic plasticity can lead vplants and animals to respond differently to temperature in different parts oftheir range. To date, there have been...
When hosts have a long coevolutionary history with their parasites, fitness costs of chronic infection have often been assumed to be negligible. Yet, experimental manipulation of infections sometimes reveals effects of parasites on their hosts, particularly during reproduction. Whether these...
We compared baseline and maximal cortisol concentrations between predator exposure and prey blood samples in pumpkinseed Lepomis gibbosus, captured using a standardised fishing event underneath osprey Pandion haliaetus nests and away from osprey nests. We did not detect differences...
Overwintering is a critical part of the annual cycle of animals living at high latitudes, and selection of overwintering sites (hibernacula) is important to population persistence. Identifying the overwintering sites of aquatic species is challenging in areas...
Overwintering is a critical part of the annual cycle of animals living at high latitudes, and selection of overwintering sites (hibernacula) is important to population persistence. Identifying the overwintering sites of aquatic species is challenging in areas where water bodies...
Research has identified numerous conservation benefits attributed to the use of marine protected areas (MPAs), yet comparatively less is known about the effectiveness of freshwater protected areas (FPAs).
This study assessed multiple long‐standing (>70 years active) intra‐lake FPAs in three...
Individual variation in parasite defences, such as resistance and tolerance, can underlie heterogeneity in fitness and could influence disease transmission dynamics. Glucocorticoid hormone concentrations often change in response to fluctuating environmental conditions and mediate changes in immune function, resource allocation...
Research in a variety of vertebrate taxa has found that cardiac function is a major limiting factor in the ability of animals to cope with physiological challenges, and thus is suggested to play an important role in mediating fitness-related behaviors...
Closely related species with overlapping geographic ranges encounter a significant challenge: they share many ecological traits and preferences but must partition resources to coexist. In Ontario, potentially eleven species of carrion beetles (Coleoptera: Silphidae) live together and require vertebrate carrion...
Electric fish handling gloves (FHGs) have been developed to immobilize fish during handling, with the potential benefit of reducing the time needed for sedation and recovery of fish relative to chemical anaesthetics. We examined the secondary stress responses (i.e., hematocrit...
The dear enemy effect arises when territorial animals respond more intensely to unfamiliar strangers than to familiar neighbours. This widespread behavioural phenomenon occurs because strangers represent a threat to both an animal's territory and parentage whereas neighbours represent a threat only...
Interactions between multiple anthropogenic stressors can have unexpected synergistic or antagonistic effects, making it difficult to predict their combined effects using single‐stressor studies. The interaction between invasive consumers and nutrient enrichment is particularly important as both stressors frequently co‐occur, and...
Using coverboards to monitor herpetofauna is common practice, yet few studies have formally tested the efficacy of using coverboards. We tested whether using coverboards on survey plots increased the number of small snakes detected in eastern Ontario, Canada. We set...
The consequences of stress on the behaviour of wild creek chub Semotilus atromaculatusoutside the reproductive period were studied using a single intra‐coelomic injection of cortisol, suspended in coconut butter, to experimentally raise plasma cortisol levels. Behaviour between cortisol‐treated, sham‐treated...
The foraging ecology of fish is often considered to be the primary determinant of body shape due to tight links between morphology, swimming performance, and foraging efficiency. Fish foraging on littoral benthic macroinvertebrates typically have a deeper body shape than...
Competition is generally regarded as an important force in organizing the structure of vegetation, and evidence from several experimental studies of species mixtures suggests that larger mature plant size elicits a competitive advantage. However, these findings are at odds with...
Theory has produced contrasting predictions related to flowering time overlap among coexisting plant species largely because of the diversity of potential influences on flowering time. In this study, we use a trait‐based null modelling approach to test for evidence of...
Androgens are known to mediate aggressive and defensive behaviour in many vertebrate species. However, high concentrations of androgens might also conflict with the expression of nurturing behaviours and therefore a trade‐off can exist between aggressive and nurturing behaviours during parental...
The diets of 99 pumpkinseed sunfish Lepomis gibbosus from a pair of small, adjacent lakes in Ontario, Canada, were estimated from their stomach contents, trophically transmitted parasites and stable isotopes of carbon and nitrogen in fish tissue. The three methods...
We investigated sexual size dimorphism and trophic morphology dimorphism in Eastern Garter Snakes (Thamnophis sirtalis) to test predictions derived from the reproductive role hypothesis. Our first objective was to examine whether structures involved in feeding (head and jaws)...
Angling is a popular recreational activity across the globe and a large proportion of fish captured by anglers are released due to voluntary or mandatory catch-and-release practices. The handling associated with hook removal and return of the fish to their...
We reviewed the literature in an attempt to determine the importance of aseptic technique when implanting electronic tags in fish. Given that there was negligible information on this topic we embarked on a study where bluegill (Lepomis macrochirus)...
The influence of feeding on swimming performance and exercise recovery in fish is poorly understood. Examining swimming behavior and physiological status following periods of feeding and fasting is important because wild fish often face periods of starvation. In the current...
Basking is a common thermoregulatory behaviour in many ectotherms, including reptiles. Because the key physiological processes affecting net energy retention (NER) are temperature dependent, ectotherms have the potential to modulate their energy budget by using basking behaviour. Many aquatic chelonians...
Although locomotory performance in vertebrates is related to fitness, most performance tests are conducted in a laboratory setting, or in a manner that forces the organism to move not of their own volition. Biotelemetry offers the possibility to measure voluntary...
Female-limited polymorphism is often attributed to selection to avoid excessive male mating attempts. It is encountered in various taxonomic groups, but is particularly common in damselflies, where one female morph (andromorph) typically resembles the conspecific male in colour pattern, while...
Our understanding of animal communication is expanding from a dyadic framework of one signaler and one receiver to a broader communication network model, yet empirical studies of communication networks are scarce. To investigate whether territorial males eavesdrop on interactions occurring...
Catch‐and‐release (C&R) angling is widely practised by anglers and is a common fisheries management strategy or is a by‐product of harvest regulations. Accordingly, there is a growing body of research that examines not only the mortality associated with C&R, but...
This study evaluated how different angling practices affect the short‐term post‐release behaviour of nest‐guarding male black bass, Micropterus spp. Male largemouth bass, M. salmoides (Lacepède), and smallmouth bass, M. dolomieu(Lacepède), were angled from their nests and subjected to treatments...
At present, there is a reasonable understanding of the independent effects of catch-and-release (C&R) angling stressors, such as air exposure and water temperature, on endpoints such as physiological disturbance, behavioural impairment and mortality. However, little is known about the multiplicative...
The mating system of flowering plant populations evolves through selection on genetically based phenotypic variation in floral traits. The physical separation of anthers and stigmas within flowers (herkogamy) is expected to be an important target of selection to limit self‐fertilization...
In territorial species, increased density is often linked to an increase in aggressive interactions, which may result in trade‐offs between competitive behavior and nest construction. We examined the impact of nesting in areas of high‐density versus low‐density nest boxes on...
We studied parental behavior in six syntopically breeding species of centrarchid fishes to determine whether energetic costs could contribute to our understanding of the diversity of parental care. We used a combination of underwater videography, radio telemetry and direct observation...
The ecological risks of polynuclear aromatic hydrocarbons (PAH) in aquatic sediments will vary with both toxicity and bioavailability to aquatic biota. While there are standardized protocols to test the acute toxicity of sediment-borne compounds to aquatic invertebrates, there are none...
Predicting ecological consequences of climate change will be improved by understanding how species are affected by contemporary climate variation, particularly if analyses involve more than single ecological variables and focus on large-scale climate phenomena. I used 18 years of data from...
Pentachlorophenol (PCP) is a general metabolic poison used extensively as a biocide in many industrial applications and as such is a contaminant in many bodies of water (Rao 1978, Jones 1981). A primary action of PCP is the uncoupling of...
To resolve conflicting field observations regarding the action of sexual selection, we used breeding experiments and paternity analysis of the 927 resulting offspring to assess how male size, condition, tail length, genetic similarity to the female, and variation in operational...
Why do females of many species mate with more than one male? One of the main hypotheses suggests that female promiscuity is an insurance mechanism against the potential detrimental effects of inbreeding. Accordingly, females should preferably mate with less related...
We examined the effects of song tutoring on adult song preferences, volume of song‐control brain regions, and activity of auditory brain regions in female house finches (Carpodacus mexicanus). Hand‐reared females were tutored with local songs, foreign songs, or...
Crown average canopy trees during an ice storm in January 1998 in an eastern Ontario woodland average canopy openness (per cent open sky) to 23.6% from 8.8% in the previous growing season. The resulting effects of increased sugar penetration ( Acer...
Rock bass (Ambloplites rupestris) are a widespread centrarchid species with both riverine and lacustrine populations. After precipitation events, rivers often carry elevated silt loads, where as lakes generally remain free from suspended silt and sediment. To examine the...
Inbreeding is a major component of the mating system in populations of many plants and animals, particularly hermaphroditic species. In flowering plants, inbreeding can occur through self‐pollination within flowers (autogamy), self‐pollination between flowers on the same plant (geitonogamy), or cross‐pollination...
Most moths use ears solely to detect the echolocation calls of hunting, insectivorous bats and evoke evasive flight manoeuvres. This singularity of purpose predicts that this sensory behavioural network will regress if the selective force that originally maintained it is...
Landing nets used by recreational anglers can be constructed of a variety of different mesh materials. Anglers and fisheries managers have hypothesized that mesh type may affect injury rates and fish survival. To test this hypothesis, we used bluegill (...
Localized dispersal and mating may genetically structure plant populations, resulting in matings among related individuals. This biparental inbreeding has significant consequences for the evolution of mating systems, yet is difficult to estimate in natural populations. We estimated biparental inbreeding in...
Turning, pectoral fin and caudal fin rates and time spent on the nest of male rock bass Ambloplites rupestris, engaged in parental care, were not affected after the attachment of external radio transmitters. Reproductive success was similar between treatment...
Turning, pectoral fin and caudal fin rates and time spent on the nest of male rock bass Ambloplites rupestris, engaged in parental care, were not affected after the attachment of external radio transmitters. Reproductive success was similar between treatment and...
Mating in plants is usually mediated by animals, yet few studies have determined whether the mating system of plant populations changes in response to variation in the taxonomic composition or to the foraging behavior of animal pollinators. Here, I investigate...
We present experimental evidence for a water-borne female-produced sex pheromone in aquatic parasitengonine mites. Water that has contained adult female Arrenurus manubriator Marshall will elicit arrestant behaviour in conspecific adult males, and if the cue is sufficiently strong, the males...
It is generally expected that small, isolated populations will suffer reduced fitness due to inbreeding, yet few studies have investigated the relation between population characteristics, inbreeding and fitness. Among Ontario populations of the short‐lived, perennial plant Aquilegia canadensis, large...
Dichogamy is very common in flowering plants and is widely thought to reduce pollen‐pistil interference, especially self‐pollination. Yet, the functional significance of dichogamy has rarely been studied. We investigated the nature and functioning of dichogamy in eastern Ontario populations of ...
In many avian species, a part of the population is present at the breeding grounds but does not breed. Current theories generally assume that floaters are younger or lower-quality individuals, and empirical data confirm this. However, floating could also arise...
We examined whether experimental parasitism by a mite Limnochares americana (Lundblad) affected survivorship and maturation of adult damselflies Enallagma ebrium (Hagen). We then tested whether differences in grooming activity between control and exposed individuals (within different age or sex categories...
In self-compatible plants, small populations may experience reduced outcrossing owing to decreased pollinator visitation and mate availability. We examined the relation between outcrossing and population size in eastern Ontario populations of Aquilegiacanadensis. Experimental pollinations showed that the...
Tree swallows (Tachycineta bicolor) show one of the highest levels of extrapair paternity in birds, and there is evidence that females have control over who fathers their offspring. However, it is unclear which benefits female tree swallows obtain...
The proportion of extrapair paternity is known to vary greatly among species, but differences between populations of the same species have rarely been considered. We used microsatellite DNA markers to assess parentage of offspring in a subarctic population of the...
The effects of shoot apex removal may be used to evaluate the cost of apical dominance and the cost of reproduction in plants. Plants that have shoot apices removed may have lateral meristems released from apical dominance and thus, may...
Before the onset of female fertility, we removed 12 early–settling male tree swallows (Tachycineta bicolor) from their nest–boxes and mates, and allowed replacement males which had been floaters to settle with the original female residents. We predicted that...
Although a goal of fisheries management is to understand factors affecting the growth rate and size structure of exploited populations, the relation between growth rates and variation in reproductive behaviors in Lepomis species has received little attention. Allocation of energy...
