Ticks in the family Ixodidae are important vectors of zoonoses, including Lyme disease (LD), which is caused by spirochete bacteria from the Borreliella (Borrelia) burgdorferi sensu lato complex. The blacklegged tick (Ixodes scapularis) continues to expand across Canada, creating hot spots of elevated...
Habitat loss and fragmentation are among the greatest threats to wildlife and biodiversity. Reptiles are particularly susceptible to these threats due to high site fidelity, large home ranges, and slow movement rates. To understand behavioral responses of Eastern Milksnakes (...
Biparental care presents an interesting case of cooperation and conflict between unrelated individuals. Several models have been proposed to explain how parents should respond to changes in each other’s parental care to maximize their own fitness, predicting no change, partial...
Upon hearing a conspecific signal, animals must assess their relationship with the signaller and respond appropriately. Territorial animals usually respond more aggressively to strangers than neighbors in a phenomenon known as the “dear enemy effect”. This phenomenon likely evolved because...
Turtles are vulnerable to population declines in response to even low levels of additional adult mortality, for instance bycatch mortality. Inland commercial fisheries that use passive gears such as fyke nets cause the drowning of some freshwater turtles. To reduce...
A recent study of Ratsnakes (Elaphe obsoleta) in Texas found that adult mortality was higher for females than males, consistent with the cost of reproduction in snakes being higher for females. To determine whether the same pattern prevailed...
Variation in the level of competition for mates and territories is likely to influence the behaviour of competitors. The start of the dawn chorus in singbirds is influenced by a variety of internal factors (e.g. circadian rhythms) and external factors (e.g. light...
We investigated the distinctiveness of males' song and the relationship between song variables and females' mate choice in the Golden-winged Warbler (Vermivora chrysoptera). We recorded the songs of 23 males and quantified them to examine performance-related traits and...
The central mudminnow (Umbra limi (Kirtland, 1841)) is a continuous, facultative air-breathing freshwater fish found in swamps of central Canada and northeastern USA. The first goal of this field and laboratory-based study was to characterize the physicochemical conditions of mudminnow habitat...
Female-limited polymorphism occurs in different animal taxa but is particularly abundant among species of damselflies (Insecta: Odonata), most likely as a consequence of selection to avoid excessive male harassment. Recent work on the damselfly Nehalennia irene indicated that within year...
A previous study reported that climate-mediated increases in the length of the breeding season produced increasingly female-biased fledging sex ratios in Red-winged Blackbirds (Agelaius phoeniceus). Using those same data plus one additional year (11 years in total), I...
Males of many songbird species participate in a distinct chorus beginning before sunrise. Despite its ubiquity, the function of dawn chorusing remains poorly understood. We tested the social dynamics hypothesis, which states that males sing at dawn to mediate their...
It has been hypothesized that populations that are strongly connected between two periods of the year (i.e., individuals that breed in similar locations and also spend the nonbreeding season in similar locations) will be most vulnerable to population perturbations. Using...
At least once a year, birds face the energetically demanding task of molting all their flight and body feathers. As a result, most birds avoid an overlap between molt and other costly activities during the annual cycle (e.g., raising young...
For the past three years, our research group has monitored the behaviour and activity of largemouth bass (Micropterus salmoides) year-round at the Warner Lake Ecological Observatory (WLEO) in eastern Ontario. The core of the WLEO is a novel...
Individual variation in morphology has been linked to organismal performance in numerous taxa. Recently, the relationship between functional morphology and swimming performance in teleost fishes has been studied in laboratory experiments. In this study, we evaluate the relationship between morphology...
Past studies of offspring sex ratios in birds have often relied on sexually size dimorphic species where nestling sex could be determined based on weight at a given age. DNA‐based sexing techniques allow us to assess the accuracy of those...
Many fishes are characterized by intense sperm competition between males that use alternative mating tactics. In externally fertilizing fishes, males’ proximity to females during spawning can be an important determinant of fertilization success. Here, we assess how mating tactic, body...
Identifying microhabitat preferences is important in understanding distributions of organisms and crucial to focusing conservation efforts. The Five-Lined Skink (Eumeces fasciatus) is a rock-dwelling diurnal lizard that, in Canada, is considered a species of “special concern” under the recently passed...
In socially monogamous species, extra-pair paternity has the potential to increase the variance in male reproductive success, thereby affecting the opportunity for sexual selection on male extravagant ornamentation. In the European barn swallow (Hirundo rustica rustica), the tail...
Male bluegill displays one of two life history tactics. Some males (termed “parentals”) delay reproduction until ca. 7 years of age, at which time they build nests and actively courts females. Others mature precociously (sneakers) and obtain fertilizations by cuckolding...
Bergmann's rule, the tendency for body size to be positively correlated with latitude, is widely accepted but the mechanisms behind the patterns are still debated. Bergmann's originally conceived mechanism was based on heat conservation; other proposed mechanisms invoke phylogeny, migration...
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...
Recently, researchers have identified that nonlethal costs of predation may arise not only from lost energy intake but also potentially from increased energetic expenditure. During periods of heightened stress following unsuccessful predation attempts, organisms may remain in an altered physiological...
Male northern water snakes (Nerodia sipedon) have high variance in reproductive success relative to females. We used DNA-based paternity analyses from a 3-year study of two marsh populations of water snakes to investigate the factors that contribute to...
In January 1998, the worst ice storm of the last century hit regions of southeastern Ontario, Quebec, New Brunswick, and the northeastern United States. Using multiple standard regression and classification trees, we examined the ice damage in a mature, deciduous forest...
Long-term data collected from an old-field community suggest that physical and environmental patterns alone may be insufficient to account for different patterns of succession. Using a simple Lotka–Volterra model to represent competition between early and late succession guilds, we add...
We describe the isolation and genetic characterization of eight microsatellite DNA loci from the northern water snake, Nerodia sipedon sipedon and use these loci to analyse levels of genetic differentiation between local (<2km apart) populations of these snakes in Ontario...
We describe 10 microsatellite loci from bluegill (Lepomis macrochirus) and discuss their evolution within the Centrarchidae. All of the loci exhibit Mendelian inheritance and are unlinked. While six loci are conserved within the Centrarchidae (found also in pumpkinseed...
We characterized the morphology of mature cuckolder and mature parental male bluegills Lepomis macrochirus from Lake Opinicon, Ontario. By rearing bluegill larvae to maturity in experimental ponds in Illinois we also examined whether morphological differences between males of the two...
Several hypotheses concerning factors that favour coexistence of female morphs in damselflies (Zygoptera: Odonata) invoke differential attraction to (or harassment of) female morphs from mate-searching males. We designed experiments to determine whether males were differentially attracted to either of two...
Because variation in fat reserves (i.e., condition) is expected to contribute to variation in survival and reproductive success, zoologists often wish to estimate the condition of the animals they study. The conventional condition estimates used for snakes are the residuals...
Black-capped chickadees (Parus atricapillus) have the ability to shift their songs up and down over a wide range of absolute frequencies. Males can shift their songs over 465 ± 52.9 (SE) Hz. During the dawn chorus, males shift...
Water mites of the genus Arrenurus vary in male sexual dimorphism and in sperm transfer behaviour. Possible adaptive functions of male courtship behaviour are discussed, including the hypothesis that male intromittant organs evolved in Arrenurus to circumvent female choice.
As a result of the viral identity of this parasite, we recommend that the etiologic agent of Toddia sp. Infections from this and other species of North American snakes be renamed Snake Erythrocytic Virus.
Movements of nonterritorial ("floater") male red-winged blackbirds (Agelaius phoeniceus) were monitored to test the hypothesis that floaters enhance their chances for territory acquisition by becoming familiar with a specific area, i.e., by restricting their geographical movements and monitoring only a...
We suggest that nest temperature or feeding conditions are the most likely factors influencing the differences in male incubation behavior between European and North American populations of barn swallows.
In this paper I synthesize original and published studies of sperm transfer behaviour of 23 genera of water mites from 15 families. The morphology of spermatophores from 16 genera (12 families) is described. Heaviour and/or spermatophores are described.
We demonstrate that the majority of female water snakes in a wild population mate with more than one male for each litter. Field observations indicated that a highly skewed operational sex ratio (3.6:1 M : F) during the breeding season...
Colored epaulets in female red-winged blackbirds (Agelaius phoeniceus) could be due either to direct sexual selection favoring the maintenance of this trait in females due to intrasexual competition for breeding opportunities, or to sexual selection favoring bright epaulets...
A demonstration of adaptive mate choice by females in resource-defence mating systems requires clear predictions as to how females should rank "breeding situations" (defined by the quality of both the resident male and the territory he defends) so as to...
Observations of territorial behaviour of male Nannothemis bella indicated that females only laid eggs on males' territories after copulating with the territory holder. Results of daily censuses of marked individuals on a study area suggested that a distinct subpopulation within...
Pentachlorophenol (PCP), a biocide used frequently in the wood preservation industry, is present at detectable levels in many bodies of freshwater (Jones 1981). Because of its wide use and the possibility of contamination of non-target organisms much is known about...
In the eighteenth century several natural historians suggested that the seemingly chaotic flight of moths was somehow related to attacks by hunting bats (see Kirby and Spence 1826), but the details of this relationship were clarified only after we under...
Macroinvertebrate populations associated with Myriophyllum exalbescens, Potamogeton richardsonii, and Vallisneria americana were compared with those on plastic ‘plants’ similar in morphology to P. richardsonii. The density of organisms varied according to macrophyte species (Myriophyllum ≫ Potamogeton > ...
Behavioral tests using freeze-dried female Red-winged Blackbird models were conducted on 11 territorial males through one breeding season. The intensity of courtship in the tests reflected recruitment success but not territory quality, indicating that those male attributes associated with territory...
In 14 cohabiting fish species in a small freshwater lake, mouth and body structures combine with food specializations and habitat preferences to greatly restrict interspecific competition within the fauna.The species differ quantitatively in a large number of structures and, individually...
