Although the evasive flight of eared moths to attacking bats has received much attention in the literature, no studies have been made of the potential costs for this behaviour. We examined the fate of moths that land upon the surface...
Evidence is reported for size‐dependent (allometric) gender allocation in the monoecious, wind‐pollinated annual Ambrosia artemissifolia. Consistent with established theory, the pattern of allometry displayed adaptive plasticity, depending on the environmental cause of variation in plant size. Plant size gradients...
The sub‐lethal effects of catch‐and‐release angling have been poorly studied because of the difficulties in monitoring physiological parameters in free‐swimming fish. Laboratory studies provide the opportunity to examine sub‐lethal effects in controlled environments, but do not incorporate site‐specific characteristics. In...
Remote measurement of the physiology, behaviour and energetic status of free-living animals is made possible by a variety of techniques that we refer to collectively as ‘biotelemetry’. This set of tools ranges from transmitters that send their signals to receivers...
The two-note fee-bee song of male black-capped chickadees functions during the dawn chorus, in part, as a sexual signal across large distances. How song structure might encode information about male quality, however, remains unclear. We studied the availability of cues...
Nonequilibrium conditions due to either allopatry followed by secondary contact or recent range expansion can confound measurements of gene flow among populations in previously glaciated regions. We determined the scale at which gene flow can be estimated among breeding aggregations...
Whether the Pleistocene has had a disproportionate impact on the recent diversification of temperate species, or played a lesser role in a more protracted process, has been a prominent evolutionary debate for the past decade. We used cytochromeb...
To determine the consequences of dispersal and gene flow for temporary pond water mites (Hydrachnida), we compared distributional, genetic and morphological characters in the closely related species Arrenurus angustilimbatus and A. rufopyriformis. The former has larvae that parasitise and disperse...
Within a network of communicating individuals, animals may gather information about the relative quality of conspecics by eavesdropping on their signalling interactions. For territorial male songbirds, eavesdropping may be a low-cost, low-risk method for assessing the relative quality of the...
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...
Some, but not all, jurisdictions in North America have regulations in place designed to protect nesting male largemouth bass Micropterus salmoides and smallmouth bass M. dolomieu from angling. The underlying assumption that brood‐guarding males are particularly vulnerable to angling, however...
Animals often exhibit territorial spatial structure in their breeding habitat. This clustering behavior is not well understood. We reviewed eight hypotheses for clustering and tested two ecological hypotheses for the formation of dense, territorial clusters in the Least Flycatcher (...
Males of many species are characterized by alternative mating tactics. In bluegill sunfish (Lepomis macrochirus), some males delay maturation and become “parentals” while other males mature precociously and become “cuckolders.” Parentals use an overt, territorial mating tactic, defending...
We assessed the effect of radiotelemetry on the growth, reproduction, and survival of black ratsnakes (Elaphe obsoleta) using data from a 6‐year study. Transmitters were surgically implanted for more than one year and were <2.5% of the snakes'...
The Cerulean Warbler (Dendroica cerulea) tops many lists of species of conservation concern because of severe population declines and habitat loss. Here we present the first robust estimates of annual survival and population growth rates for this species...
The bulk of Lake Opinicon fish biomass is concentrated in the physically diverse inshore areas. Quantitative analysis of the community compositions of the various inshore habitat types (weedy inlets, sandy shallows, rock shelf, gravel, etc.) showed that each supported a...
Neuronal recruitment in the black-capped chickadee (Poecile atricapillus) hippocampus occurs at a higher rate in the fall than at other times of the year. As a means of determining whether this increase in recruitment results from greater neuron...
Nocturnal flight exposes insects to selection pressures that include reduced light and the hunting behavior of insectivorous bats. Using a phylogenetically based selection of wild moths collected from a Nearctic site, we report that earless species fly less throughout the...
During vocal contests, animals alter both the timing and the patterning of responses to their opponents. Time-specific responses (such as overlapping an opponent's song) and pattern-specific responses (such as matching the type of an opponent's song) may reveal information about...
In sexually promiscuous animals, females may benefit by nesting close to the edge of their partner's territory to facilitate extrapair copulations. In the present study, we describe the extrapair mating system of black-capped chickadees, Poecile atricapillus, and test whether...
Auditory sensitivities and ultrasound avoidance behaviour of two exclusively diurnal moths were examined to test the prediction that total isolation from the predatory effects of echolocating bats will result in the regression of these sensory systems and/or the defences they...
Nest-site selection is the only behaviour that can be considered parental care in most oviparous reptiles because eggs are abandoned after laying and because incubation conditions resulting from nest-site selection can have profound effects on offspring. During a 7-year study...
In the current study, we simulated different components of a live‐release angling tournament (angling, live‐well confinement, and weigh‐in) to determine the relative physiological significance of these tournament components for largemouth bass Micropterus salmoides. Our results indicated that depletions of...
Single-species habitat management strategies are often undertaken without explicit consideration of their effects on the larger community. Here we explore the potential effects of managing eastern Ontario deciduous forests for the Cerulean Warbler (Dendroica cerulea) by examining its...
We examined whether differences among hosts in timing of emergence of phenotypic attributes might affect their probability of return to an emergence pond, and hence success of mites.
We examined the relationship between non-polar lipid density, parasite density and paternity of male bluegill sunfish, Lepomis macrochirus, and four condition factors: (1) Fulton’s condition factor, K; (2) the relative condition factor, Kn; (3) the relative mass index, Wr; and...
Toward the end of the breeding season, migratory songbirds face crucial tradeoffs between the timing of reproduction, molt, and migration. Using stable hydrogen isotopes, we show that male American redstarts investing in high levels of reproduction late in the season...
Flowering plants often exhibit declining investment in gametes, seeds, and floral organs among sequentially blooming flowers within inflorescences. However, few experimental studies have determined the relative importance of proximate underlying causes such as architectural constraints or resource competition among flowers...
Although in birds and mammals sex‐specific differences in organismal performance and physiology are well documented, comparatively little is known about the influence of sex or reproductive status on fish performance or metabolism.
In this study, the resting cardiovascular performance of...
Low frequency of reproduction among iteroparous organisms is most often observed among female ectothermic vertebrates and is thought to be a strategy used to defer reproductive costs. We assessed reproductive costs of male water snakes (Nerodia sipedon) to...
Colonial breeding can evolve in response to benefits afforded by clumped individuals, such as reduced predation and increased ease of assessing potential mates. However, colonial breeding can also impose costs such as increased disease transmission or increased cuckoldry. Here, we...
An important problem in understanding the evolution of parasite host range is determining the extent to which parasite fitness varies among host species and the factors affecting that fitness variation. We present a detailed investigation on the patterns of host...
Under sperm competition, a male’s fertilization success depends largely on the ejaculate characteristics of competing males. Theoretical models predict that, in external fertilizers, increased risk of sperm competition should result in selection for increased sperm swimming speed. To test this...
Sperm traits (morphology, motility and concentration within ejaculates) and various correlates of male quality (age, body condition, spawning location and timing) were studied in bluegill Lepomis macrochirus, breeding in both the interior and periphery of six colonies in Lake...
Conservation programs use breeding protocols to increase genomic divergence (by mating genetically dissimilar individuals) in an attempt to circumvent population declines resulting from inbreeding depression. However, disruption of either beneficial gene complexes or local genetic adaptations can lead to outbreeding...
The damage caused by biological invasions has traditionally been thought to result from alien species taking advantage of ecological differences between the native and introduced ranges. In contrast, the role of evolutionary forces has received relatively little attention. Our results...
Prey that are unprofitable to attack (for example, those containing noxious chemicals) frequently exhibit slower and more predicable movement than species that lack these defenses. Possible explanations for the phenomenon include a lack of selection pressure on unprofitable prey to...
Prey species that are unprofitable to attack often share conspicuous colours and patterns with other coexisting defended species. This phenomenon, termed müllerian mimicry, has long been explained as a consequence of selection on defended prey to adopt a common way...
Although broad habitat preferences are known for many species of conservation concern, identification of key microhabitat elements critical to persistence and reproduction is a crucial and generally understudied aspect in conservation. In this study, we examined diurnal microsite selection in...
Identifying the factors that control population dynamics in migratory animals has been constrained by our inability to track individuals throughout the annual cycle. Using stable carbon isotopes, we show that the reproductive success of a long‐distance migratory bird is influenced...
Molecular techniques have allowed researchers studying mating systems to determine the identity of extra-pair sires, providing more accurate measures of individual realized reproductive success. Yet, an existing problem in such studies is the inability to assign paternity to individuals that...
The thermal coadaptation hypothesis predicts that (1) ectotherms experiencing a narrow range of body temperatures in the wild will evolve to perform well over a narrow range of body temperatures and that (2) the optimal temperature for performance will be...
We investigated the mating patterns in 22 breeding pairs of wild American goldfinches (Carduelis tristis) with respect to their body size, condition, and carotenoid-based, yellow plumage colour. Using reflectance spectrometry, we objectively quantified plumage colours across the bird-visible...
The simple auditory system of noctuoid moths has long been a model for anti-predator studies in neuroethology, although these ears have rarely been experimentally stimulated by the sounds they would encounter from naturally attacking bats. We exposed the ears of...
We present behavioural data demonstrating that the little brown bat, Myotis lucifugus, and the northern long-eared bat, M. septentrionalis, can glean prey from surfaces and take prey on the wing. Our data were collected in a large outdoor flight...
In this study we examined the effects of exhaustive exercise and brief air exposure on the cardiovascular function of largemouth bass Micropterus salmoides at four water temperatures (13, 17, 21, and 25°C). We used Doppler flow probes to monitor cardiac...
Evolutionary ecologists are attempting to explain how parents make behavioural decisions about how much care to provide to their young. Theory predicts that when genetic relatedness to young is decreased by cuckoldry, for example, parents should reduce their care in...
The damselfly, Nehalennia irene (Hagen), has two distinct female colour morphs. Individuals of one morph have male‐like colouration and pattern (androchromes), whereas gynochromes are different from males and androchromes in these respects. In several damselflies, such female‐limited polychromatism is attributable...
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...
