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Nicholas C. Collins

Nicholas C. Collins
University of Toronto, Toronto (grad) and University of Toronto Mississauga (undergrad) · Dept. of Ecol. and Evol. Biology (grad) and Dept. of Biology (undergrad)

PhD (U. of Georgia)

About

50
Publications
7,628
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2,102
Citations
Citations since 2017
0 Research Items
416 Citations
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Introduction
1. ESTIMATES of effect sizes and false discovery rates in ecol. and evol. biology. 2. OPEN SCIENCE METHODS to reduce levels of false positives and publication bias. 3.CONSEQUENCES of the preponderance of small sizes of what we would expect to be strong effects in almost every discipline. 4. HOW annual pre-reproductive survival for hunter gatherers could reliably average >95% over 15 years to maturity in a world filled with influences that are typically highly unreliable (r2 < 0.03).
Additional affiliations
July 2008 - June 2017
University of Toronto, Toronto (grad) and University of Toronto Mississauga (undergrad)
Position
  • Chair
July 1973 - present
University of Toronto Mississauga
Position
  • My graduate appointment is to this department

Publications

Publications (50)
Research
Full-text available
We identify the most important characteristics of the equipment necessary for underwater time-lapse monitoring, pointing out the characteristics of the currently available equipment that most limit performance. Our focus is on technical requirements, rather than on the capabilities of currently available equipment, so that the discussion should rem...
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Along 25 km of the Lake Ontario shoreline near Toronto, Ontario, small coastal embayments (0.4–32 ha) have been constructed or modified by lake-infilling to restore warmwater fish habitat. The variation in thermal habitat quality for warmwater fishes among these embayments is very high; temperatures range from those found within a small pond to tho...
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Coastal embayments have been and will continue to be constructed along the northwest shoreline of Lake Ontario to restore and create warmwater fish habitat. However, very little is known about the biological connections among embayments. Using otolith microchemistry on pumpkinseed, largemouth bass and yellow perch collected from three constructed e...
Article
Little is known about the ecology of warmwater fish in small coastal embayments (< 32 ha) where temperatures are lowered by exchange with the adjacent lake. Using pumpkinseed (Lepomis gibbous) as a model warmwater fish, we compare hatch dates and overwinter survival in two embayments with higher and lower amounts of cold-water input from Lake Ontar...
Article
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Sexual size dimorphism of walleye (Stizostedion vitreum vitreum) is achieved by females having higher growth rates than males before and after maturation, resulting in females with greater asymptotic sizes. Mercury (Hg) concentrations in epaxial muscle by age and weight for 31 populations of walleye were used to evaluate the relative importance of...
Article
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Fish activity near the bottom was monitored in two central Ontario lakes using time-lapse video equipment. Predation risk for benthic invertebrates was measured as the frequency of fish entries into a hypothetical cylinder with dimensions such that an imaginary 2–3 mm invertebrate at the bottom-center of the cylinder would be within the detection r...
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Empirically derived estimates of prey resources using conventional sampling methods are generally poor indices of actual food available to visually feeding benthivorous fish. We preferentially sampled the most active fraction of the benthos (presumably that most detectable by fish) utilizing short-term (4 d) colonization of artificial substrates, a...
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We collected data on the most frequently encountered medium- to large-bodied littoral fishes in two independent sets of central Ontario lakes; the first set (10 lakes) was sampled between 1979 and 1980 and the second (15 lakes) from 1982 to 1988. Empirical models were constructed by correlating the strongest with in-year, among-lake trends in speci...
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In 19 central Ontario lakes the catches of crayfish in baited minnow traps usually were well predicted by numbers of crayfish counted in timed underwater searches. Exceptions were lakes with relatively high predator densities, where trap catches were far less than expected from search counts. In a stepwise linear regression, an index of the density...
Article
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Smallmouth bass (Micropterus dolomieu) nests were patchily distributed within the littoral zone of Lake Opeongo at two spatial scales (1 km and 100 m shoreline segments). Nest locations were recorded by snorkelling along 155 and 6.3 km of littoral zone over 4 and 11 years, respectively. The degree of patchiness was greater and occurred more consist...
Article
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Along 40km of the Lake Ontario shoreline near Toronto, Ontario, small coastal embayments (4.38–848×103m2) have been constructed or modified by lake-infilling to restore warmwater fish habitat. We describe how the thermal regimes of these embayments differ from those of small inland lakes, how embayment bathymetry alters the degree of exchange with...
Article
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The mating patterns of three slimy sculpin populations from central Ontario were examined using SCUBA to determine the relationship between the degree of polygyny and the relative availability of potential nest sites. We found that sculpins were exclusively polygynous in a lake where nests were probably limiting, while in two other lakes where pote...
Article
To evaluate the importance of non-consumptive effects of predators on prey life histories under natural conditions, an index of predator abundance was developed for naturally occurring populations of a common prey fish, the yellow perch Perca flavescens, and compared to life-history variables and rates of prey energy acquisition and allocation as e...
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One of the major challenges facing fishery scientists and managers today is determining how fish populations are influenced by habitat conditions. Many approaches have been explored to address this challenge, all of which involve modeling at one level or another. In this paper, we explore a process-oriented model approach whereby the critical popul...
Article
1. Differences in energy use between genders is a probable mechanism underlying sexual size dimorphism (SSD), but testing this hypothesis in the field has proven difficult. We evaluated this mechanism as an explanation for SSD in two North American percid species--walleye Sander vitreus and yellow perch Perca flavescens. 2. Data from 47 walleye and...
Article
We have developed an age-structured, spatially explicit model to estimate smallmouth bass (Micropterus dolomieu) population dynamics from the readily available habitat data of a lake. Habitat suitability models were used to rank the suitability of different sites throughout a lake for smallmouth bass. Population dynamics were then linked to the hab...
Article
Full-text available
Sex-specific life history variation was examined among 72 populations of yellow perch Perca flavescens from Ontario, Canada. We sought to determine whether relationships could be applied to other populations to predict parameter values when life history data are not available. Each of the measured traits (early growth rate, maturation size and age,...
Article
Using lake trout (Salvelinus namaycush) and walleye (Sander vitreus) we examined the extent of error that is created when non-population-specific or non-sex-specific data are used to develop fishery sustainability models. To put biases in perspective we first compared relative differences in sustainable harvest rate estimates of fast and slow growi...
Article
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Multivariate analyses on benthic invertebrate methylmercury concentrations ([MeHg]) and water chemistry from 12 Quebec water bodies were used to guide the construction of simple, predictive models of benthic invertebrate [MeHg] in 23 lakes in Ontario and Quebec. Separate predictive models for collector–shredder and predatory benthic invertebrates w...
Article
Growth (length, weight) of yellow perch Perca flavescens in western and west-central Lake Erie began between June and July, possibly reaching asymptotic size by early winter. Energy density (kJ g−1) of somatic tissue increased markedly from June to September, then declined to low levels by the following spring. Consequently, energy mass (kJ) of som...
Article
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Life history variation among 60 Ontario populations of lake trout (Salvelinus namaycush), walleye (Sander vitreus), cisco (Coregonus artedii), and yellow perch (Perca flavescens) is presented and interpreted using a biphasic model of individual growth that specifically accounts for the significant shift in energy allocation that accompanies sexual...
Article
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Activity costs can account for a major proportion of fish energy budgets and may trade off against observed growth rates in wild fish populations. Recent approaches to estimating activity costs in situ have used a contaminant-bioenergetic mass balance modelling approach, allowing for a broader examination of activity costs among populations compare...
Article
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Questions: How do life-history traits covary among populations? Do two-trait models show different patterns of covariation than multi-trait models? Is covariation different for males and females? Is covariation among traits within populations (many generations) different to that among populations (one generation)? Organism: A sexually dimorphic med...
Article
Covariations of growth, age and size at maturity, and adult natural mortality rates are described for 22 Great Lakes stocks and 28 inland lake populations of lake whitefish (Coregonus clupeaformis). An understanding of these covariations could be used to modify the expectations of sustainable yields. Age at maturity was inversely related to pre-rep...
Article
Plastic Lake, Ontario, remote from any point sources of pollutants, is the most thoroughly investigated anthropogenically acidifying lake in North America. As the lake pH decreased from 5.8 to 5.6 over a period of six years, a resident population of the crayfish Orconectes virilis, which had previously exhibited abundances typical of those of nearb...
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Habitat conditions may determine locations of patchily distributed smallmouth bass nests in lakes, since young smallmouth bass are fragile and are therefore vulnerable to suboptimal physical characteristics in their typically variable nesting area, the littoral zone. Knowing which habitat conditions are important to nest locations would ultimately...
Article
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We compared pumpkinseed nesting success in two lakes having similar size, location, and water chemistry but with different fish communities. Ranger Lake had well-established populations of smallmouth and largemouth bass and few planktivorous fish, whereas Mouse Lake had no piscivores and many planktivore-benthivores capable of consuming pumpkinseed...
Article
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We used time-lapse video with infrared illumination to record feeding activity of pumpkinseeds Lepomis gibbosus in two patches of littoral habitat in a shallow, mesotrophic Ontario pond. Observations were made for 72 consecutive hours in each of eight ice-free months and include extensive, relatively nonintrusive field observations of pumpkinseed b...
Article
We used time-lapse video with infrared illumination to record feeding activity of pumpkinseeds Lepomis gibbosus in two patches of littoral habitat in a shallow, mesotrophic Ontario pond. Observations were made for 72 consecutive hours in each of eight ice-free months and include extensive, relatively nonintrusive field observations of pumpkinseed b...
Article
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Reproductive behavior has never been considered an important contributor to overall activity costs for fish and is usually ignored in fish bioenergetics models. We provide evidence that parental care by male smallmouth bass Micropterus dolomieu substantially affects both activity costs and food intake. We used timelapse underwater video with infrar...
Article
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Mutlivariate ordination techniques were used to establish relationships among the abundances of the most frequently occurring littoral zone fishes (fishes that occurred in >60% of the lakes) in 25 central Ontario lakes. Some 70% of the variation in abundances was described by the first two axes from a correspondence anlaysis. Abundances of white su...
Article
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In a series of laboratory experiments we examined the hypothesis that larvae of stream mayflies would respond to the presence of two different types of predators in such a way as to minimize their risk of being consumed by each. Positioning of larvae (whether they frequent the top, sides, or bottom of stones) of Baetis tricaudatus and Ephemerella s...
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Mottled sculpins (Cottus bairdi) have a strong negative effect on the ability of the stonefly Agnetina capitata to capture some types of mayfly prey. To determine the mechanism for this interference effect, behavior of Agnetina in the presence and absence of sculpins was observed over 24 h periods (12 h light, 12 h dark), using an infra-red sensiti...
Article
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Examined rates of prey consumption by mottled sculpin Cottus bairdi and perlid stoneflies Agnetina capitata, separately, and together. Two types of Ephemeroptera prey (Ephemerella subvaria, Baetis tricaudatus) were used. When both types of predators were present consumption of Baetis larvae was significantly less than model predictions of combined...
Article
Full-text available
Three slimy sculpin (Cottus cognatus) populations in central Ontario, Canada, were extensively surveyed using SCUBA to determine interpopulation variability in reproductive behavior. When compared to a random model (Poisson), the mating patterns varied significantly among populations. In Mountain Lake, sculpins were usually monogamous and males wer...
Article
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Larval Anas junius living in a small pond consumed largely amphipods and Chaoborus larvae. Minor components of the diet were Coleoptera, Chironomidae and Zygoptera. These prey types were consumed disproportionately to their relative abundance in the pond. Presence of sand, gravel, and Elodea stems significantly reduced the capture rate of amphipods...
Article
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The fecal pellet mass of larval Anax junius of a given size is closely correlated with food intake. The fecal pellet mass under ad libitum feeding can be predicted from a knowledge of larval size, and the accuracy of the predictions is not sensitive to wide variation in the diurnal schedule of feeding, water temperature between 15 and 25°, and diet...
Article
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A previously-developed Food Limitation Index (FLI) for larvae of the dragonfly Anax junius (Drury) was used to measure the food consumption of these animals in four water bodies in southern Ontario. Most mean FLI values from the dragonfly samples did not indicate strong food limitation, but at all sites the degree of limitation tended to increase l...
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Adaptive developmental responses to suboptimal conditions should preserve the life history traits most important to fitness at the expense of less critical traits. This paper compares responses to food limitation of Ephydra cinerea Jones (new data) to those of other Diptera (literature data) and concludes that the differences are indeed related to...
Article
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The population of Ephydra cinerea was studied during three summers when dissolved solids levels were about 130 g/l. All life stages are present year-round, but there is apparently some coordination of the initial pulse of adult emergence in June. There are probably 1–2 generations per year. Eggs are deposited on the water surface; inputs to three l...
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Of the three large ephydrid flies of Yellowstone’s thermal springs, Ephydra thermophila numerically dominates acidic springs because only it can tolerate their water. Alkaline spring effluents are shared by Ephydra bruesi and Paracoenia turbida. E. bruesi is excluded from alkaline high productivity springs, probably because its larval maturation ti...
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Low temperature (< 400C) alkaline thermal spring effluents in Yellowstone National Park support a benthic algal-bacterial mat fed upon by a single herbivorous brine fly (Diptera: Ephydridae), which in turn is consumed by a number of arthropod predators (water mites, spiders, and a predaceous fly). A census of an entire spring ecosystem provided a f...
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A filamentous, water-holding mat of a slow-growing green alga (genus Zygogonium) is the structural basis of a simple community of acid-tolerant algae and arthropods in Yellowstone National Park, USA. Populations of interstitial algae, mostly Euglena mutabilis and Chlamydomonas, infuse certain areas of the Zygogonium mat. The major herbivore, Ephydr...

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