Population decline and the threat of extinction are realities currently facing many species. Yet, in most cases, the detailed demographic data necessary to identify causes of population decline are unavailable. Using 43 years (1975−2017) of data from a box-nesting population of...
White-nose syndrome (WNS) has rendered four of Ontario’s species endangered, while leaving the other four species
relatively unaffected. The causes and extent of the declines have been widely studied. The influence on remaining bat species has
not. Comparing acoustic data...
Various aspects of performance (e.g., speed, strength, endurance) are thought to be important determinants of the success of animals in natural activities such as foraging, mating, and escaping from predators. However, it is generally known that morphological properties enhancing one...
Avian aerial insectivores, a taxonomically diverse guild of birds, are facing dire population declines. The primary commonality among these birds is that they forage on flying insects, suggesting that diet has exposed these birds to environmental challenges that cause their...
Variation in immune gene sequences is known to influence resistance to infectious diseases and parasites, and hence survival and mate choice, across animal taxa. Toll-like receptors (TLRs) comprise one essential gene family in the vertebrate innate immune system...
Parental care is an advantageous reproductive behavior, as the fitness of the caregiver is increased through improving the chances of its offspring’s survival. Parental care occurs in a variety of teleost fishes. The body size of parental fish and the...
Infectious disease represents an emerging threat to natural populations, particularly when hosts are more susceptible to novel parasites (allopatric) than to parasites from the local area (sympatric). This pattern could arise through evolutionary processes (host populations become adapted to their...
Breeding site fidelity has evolved in many vertebrate taxa, suggesting both that site selection has an important influence on fitness potential and that the decision to reuse a nesting site is related to the individual’s prior nesting success at that...
In the face of a changing world, there has been increasing interest in the behavioural and physiological responses of wild animals to stressors. Many factors can influence stress responsiveness, but two that have not been extensively studied during the stress-induced...
Sexually selected traits can signal an individual's ability to contribute offspring care. Differential allocation theory posits that when these same traits also influence brood value, it may be adaptive for partners to adjust care in response to their mates' traits. Evaluating...
Tradeoffs between hypoxia tolerance and aerobic exercise performance appear to exist in some fish taxa, even though both of these traits are often associated with a high O2 transport capacity. We examined the physiological basis for this potential tradeoff...
Turtles are caught as bycatch in commercial fisheries in both inland and marine waters. Turtle mortality associated with bycatch is concerning, as life-history characteristics of turtles, including high juvenile mortality and delayed sexual maturity, make them particularly susceptible to population...
Experimental evidence suggests that competition among plant species is generally hierarchical and that relatively large species are at a competitive advantage when competition is predominantly above‐ground. However, regional species pools are dominated numerically by relatively small plant species, and...
Parasite-mediated selection in host populations is thought to vary in magnitude temporally. We monitored variation in life history traits that are known or suspected to influence fitness in a population of damselflies parasitized by larval water mites. Mite prevalence and...
Life history theory predicts that individuals paired with attractive mates may invest more in offspring. Such differential investment may amplify the effects of genetic quality on fitness. Attractiveness can include ‘good gene’ and ‘complementary gene’ components, but how the latter affects...
Frequent copulation is assumed to be an important male reproductive strategy for paternity assurance in species with female sexual promiscuity. However, the empirical evidence supporting this hypothesis is limited. We examined copulation behaviour in relation to within-pair paternity in the socially monogamous...
Like many teleost fishes, bluegill (Lepomis macrochirus) are characterized by sole male parental care of offspring. In addition, bluegill parental males experience cuckoldry by specialized parasitic male morphs. This cuckoldry has previously been shown to influence the expression of parental...
In this study we examined trematode and nematode lung helminths commonly found in two species of host ranid frogs for competitive interactions. We examined 147 adult (breeding and non-breeding) and juvenile northern leopard frogs, and 84 breeding male wood frogs...
We examined the physiological and behavioural consequences of, and recovery from, catch-and-release related stressors using a combined laboratory and field study in northern pike (Esox lucius L.). A laboratory experiment was conducted to investigate the recovery dynamics of physiological...
Many species of birds exhibit brilliant ornamental plumage, yet most research on the function and evolution of plumage has been confined to the breeding season. In the American redstart Setophaga ruticilla, a long‐distance Neotropical‐Nearctic migratory bird, the acquisition of...
Many animals display multiple signals that can be used by conspecifics to gather information about the condition or quality of potential mates or competitors. Different signals can indicate different aspects of individual quality or function in spatially or temporally separated...
Parental care is an important, energetically costly component of the life history of many fishes. Despite this importance, little is known about how different species of fish vary parental care in response to natural nest predator burdens. In this study...
Catch‐and‐release practices are common in recreational fisheries, yet little is known about the behavior, physiology, and ultimate fate of released fish. We used a combination of radiotelemetry (external attachment) and nonlethal blood sampling (i.e., the blood concentrations of lactate and...
Victory displays are behaviours that occur after the conclusion of a signaling contest, performed solely by the contest winner. Victory displays may reinforce the dominance of the winner either to the loser or to other conspecifics within signaling range. Victory...
We examined two components of reproduction in a population of golden-winged warblers in the initial stages of hybridization with blue-winged warblers. First, we used genetic analyses of mate choice to determine whether copulations outside the social pairbond (extra-pair copulations; EPCs)...
We studied parental provisioning rates and nestling body condition in an introgressed population of Golden-winged Warblers (Vermivora chrysoptera) in eastern Ontario. Twelve nests were monitored until the young fledged; six nests were parented by phenotypically pure Golden-winged Warbler males and...
Foraging behavior under the risk of predation has interested biologists for decades. Here, we examine paternal genetic effects on foraging decisions of bluegill (Lepomis macrochirus) larvae sired by males adopting alternative life histories. We use split in vitro...
Like many teleosts, male bluegill sunfish (Lepomis macrochirus) provide sole parental care. To understand some of the proximate costs of parental care, we measured body condition and plasma levels of testosterone (T), 11-ketotestosterone (11KT) and cortisol...
Variation in intrauterine exposure to hormones associated with variation in the sex of litter mates has well‐established and far‐reaching effects on sexual development in some mammals. Research on this phenomenon in reptiles is scant, but suggests that lizards may follow...
Kin selection theory has been one of the most significant advances in our understanding of social behavior. However, the discovery of widespread promiscuity has challenged the evolutionary importance of kin selection because it reduces the benefit associated with helping nestmates...
Understanding the trade‐off females make between offspring size and number requires knowing how neonatal size, and traits associated with size, affect survival. We studied neonatal survival in the northern watersnake Nerodia sipedon in outdoor enclosures with artificial hibernation sites. From...
Cerulean warblers (Dendroica cerulea) have experienced significant declines across their breeding range and presently exist in disjunct populations, largely because of extensive loss and fragmentation of their breeding and wintering habitat. Despite this overall decline, a recent north-eastern...
Although most of the studies on the evolution of mimicry and warning signals in insects have considered birds as the main predators, predation by other taxonomic groups, such as insects, may far exceed avian predation at some localities. However, few...
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...
Theory of parental care evolution predicts that a parent should invest more in a brood when its fitness value is greater than alternative investments such as the parent's own survivorship or future broods. In fish, filial cannibalism (eating one's own...
In seasonal environments animals organize their behaviour around annual cycles of resource availability. Wild black-capped chickadees are most likely to hoard food in autumn. At this time of year chickadees are also reported to have a larger hippocampus, a brain...
The fee-bee song of male black-capped chickadees (Poecile atricapillus) is considered a single-type song that singers transpose up and down a continuous frequency range. While the ability to shift song pitch in this species provides a mechanism for...
My general goal in this paper was to quantify both the precision and accuracy of snout-to-vent length measurements in black ratsnakes, a large constricty colubrid.
Male smallmouth bass (Micropterus dolomieu) and largemouth bass (Micropterus salmoides) care for their offspring from fertilization until the offspring disperse after becoming capable of avoiding predators. We used activity transmitters to monitor round-the-clock parental activity of...
Understanding how life histories influence reproductive success under uncertain conditions is necessary to predict population dynamics. For many organisms, protracted reproduction may increase expected offspring recruitment in variable environments, requiring that temporal patterns of reproduction be considered when developing management...
The spawning behavior of male and female largemouth bass Micropterus salmoides (Lacépède) was studied in central Illinois during the spring of 1998 to examine patterns of muscular activity associated with different spawning related behaviors and to evaluate whether electromyogram (EMG...
Least flycatchers (Empidonax minimus) are socially monogamous birds that form tight territorial aggregations on the breeding grounds. We designed five polymorphic microsatellite loci for assigning parentage to offspring within least flycatcher clusters. The number of alleles per locus...
Least Flycatcher Empidonax minimus pairs form dense clusters of territories on the breeding grounds. We describe pair formation and copulation behavior (both within- and extra-pair) in Least Flycatcher clusters. Pair formation involved a complex behavioral sequence of trill vocalizations and...
Paleolimnological techniques were used to infer long-term changes in trophic status of Lake Opinicon (Ontario), a mesotrophic, shallow, macrophyte-dominated lake, and to assess whether these patterns support the hypothesis of 'alternative equilibria' proposed for shallow lake systems. Analysis of the...
Many breeding systems include ‘multiple mating’ in which males or females mate with multiple partners. We identify two forms of multiple mating: ‘single‐sex’, where the next‐generation individuals (NGIs) are the product of multiple mating by one sex; and ‘two‐sex’, where...
Substantial individual variation in timing of emergence from hibernation has been reported among reptiles. Here we report patterns of spring emergence by black snake rat (Elaphe obsoleta obsoleta) observed at 13 communal hibernacula in eastern Ontario from 1992-1997. Because our study is...
We investigated whether the thermal history of Black Rat Snakes (Elaphe obsoleta) and Northern Water Snakes (Nerodia sipedon) during development affected their preferred body temperatures (PBT) after hatching or birth. Eggs of black rat snakes were...
Interspecific comparisons suggest that a trade-off exists between development and somatic growth rate. We provide evidence for a trade-off between cranial ossification and growth rate within a single species, the pumpkinseed sunfish (Lepomis gibbosus). We compare fish derived...
Using field surveys and histological methods, we show that a dragonfly species (Sympetrum internum) has an effective resistance, not seen previously in other odonates, to a mite parasite (Arrenurus planus). This mite is a generalist parasite...
Assessments of population genetic structure and diversity can be of value in formulating management plans for threatened species. Using randomly amplified polymorphic DNA markers, we found evidence of significant genetic structure among black rat snakes ( Elaphe obsoleta) sampled at three...
We found high population densities of Hydra canadensis (up to 30,000 m ‘) on macrophytes in Lake Opinicon (Ontario, Canada) and tested whether they influenced the survival of larval bluegill, Lepomis macrochirus. Hydra were observed to capture and ingest bluegill...
We used laboratory experiments to show that the nonlethal presence of pumpkinseed sunfish (Lepomis gibbosus) results in smaller size at emergence, decreased growth and development rates, and lower fecundity of the dipteran Chironomus tentans. Smaller size at metamorphosis is often...
We tested whether the reproductive success of male red-winged blackbirds (Agelaius phoeniceus) varied with male secondary sexual traits or with haematozoa prevalence, and whether these patterns were consistent with females preferring genetically superior males. We also determined whether...
Ecomorphological analyses that search for patterns of association between morphological and prey-use data sets will have a greater chance of understanding the causal relationships between form and diet if the morphological variables used have known consequences for feeding performance. We...
