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Introduction
Evolutionary ecologist extraordinaire, if just for the value of the alliteration. If you see any (good) jobs out there, please let me know.
Publications
Publications (34)
The immune system is costly to operate, so we expect allocation to this function to relate
to other indices of overall phenotypic condition. In captive male ruffs (Philomachus pugnax), we
examine covariation between three seasonal male characteristics induced by testosterone (neck ‘ruff’,
facial wattles, and increases in mass/size) and cell-mediate...
Emlen and Oring (1977) suggested that monogamy in birds is maintained because of the need for strict biparental care. A corollary of their suggestion is that paternal care should decrease under conditions of high food abundance. An alternative is that paternal care would increase if males take advantage of the higher food abundance by trying to red...
Seasonal affective disorder (SAD) is a state of depression induced by a lack of sufficient sunlight that occurs at high latitudes during the fall and winter. One effect of SAD is that causes people to be more risk-adverse, an effect that should be considered by granting agencies of high latitude countries. Funding agencies often have programmes aim...
Vigil summarizes sex-related differences in emotivity, and presents a psychological model based on the restrictive assumption that responses to stimuli are dichotomous. The model uses for support the concept of intrasexual selection, but ignores intersexual selection. An alternative hypothesis might be that emotivity signals age: maturity in men an...
Anorexia nervosa is diagnosed by drastic weight loss, a fear of gaining weight, a distorted body image, and, in women, three consecutive episodes of amenorrhea. It is often associated with a compulsive need for exercise, a bright outlook on life, and a high level of competitiveness. It afflicts primarily young women in higher socioeconomic strata w...
Introduction.- Obesity is a major threat to global health. When more conventional methods have failed, obesity can be addressed via bariatric surgery. Here we examine the reasons why patients choose bariatric surgery and the behavioral consequences thereafter.
Methods.- A qualitative study with a phenomenological design was used to analyze detailed...
Alternative reproductive tactics and strategies (ARTS) refer to polymorphic reproductive behaviours in which in addition to the usual two sexes, there are one or more alternative morphs, usually male, that have evolved the ability to circumvent direct intra-sexual competition. Each morph has its own morphological, ecological, developmental, behavio...
Can ideas about the regulation of body mass in birds be used to explain the breakdown of
regulation associated with obesity and anorexia in humans? There is no evidence to think so.
Medicine can always benefit from the application of evolutionary ecology ideas, but we must
be prepared to dismiss these ideas when they just do not fit the data.
Scientists of many countries in which English is not the primary language routinely use a variety of manuscript preparation, correction or editing services, a practice that is openly endorsed by many journals and scientific institutions. These services vary tremendously in their scope; at one end there is simple proof-reading, and at the other extr...
Previous research indicates that during the past 20 years, the highest-quality work has been published in an increasingly diverse and larger group of journals. In this article, we examine whether this diversification has also affected the handful of elite journals that are traditionally considered to be the best. We examine citation patterns during...
Forbes and Mlynarek (2014) propose the "coevolutionary release hypothesis". It argues that when some host populations are not exposed to a given parasite, gene flow from the unaffected host population hinders the affected host population’s ability to evolve resistance. My paper is just a commentary on the hypothesis, highlighting some implications...
When a group of individuals creates something, credit is usually divided among them. Oddly, that does not apply to scientific papers. The most commonly used measure of the performance of individual researchers is the h-index, which does not correct for multi-authorship. Each author claims full credit for each paper and each ensuing citation. This m...
Immunity and resistance to oxidative stress are two mechanistically related aspects of self-maintenance that are usually not studied together in connection to ecological or evolutionary relevant variables. Whereas many studies compare 2 sexes, here we use ruffs (Philomachus pugnax L., 1758.), a species in which males have 3 alternative reproductive...
Historically, papers have been physically bound to the journal in which they were published but in the electronic age papers are available individually, no longer tied to their respective journals. Hence, papers now can be read and cited based on their own merits, independently of the journal’s physical availability, reputation, or Impact Factor. W...
Animals use multiple cues when choosing mates, but it is not yet clear why a single signal would not suffice. In this paper, drawing support from predation and “noise” effects on mate choice, marketing economics, and models on sexual signals, a new hypothesis explaining multiple sexual signals is proposed: the sexual interference hypothesis. The hy...
Evolutionary explanations, many of which have appeared on the pages of this journal, are becoming more pervasive and influential in medicine, so it is becoming more important to understand how these types of explanations differ from the proximate approach that is more common in medicine, and how the evolutionary approach can contribute to medicine....
The immune system is an energetically expensive self-maintenance complex that, given the risks of parasitism, cannot be carelessly compromised. Life-history theory posits that trade-offs between fitness components, such as self-maintenance and reproduction, vary between genders and age classes depending on their expected residual lifetime reproduct...
The fact that avian eggs contain antibody of maternal origin is well documented, but only recently has this phenomenon been considered in an ecological context. We used tree swallows (Tachycineta bicolor) to examine the possibility of transgenerational immunity and its effect on nestling growth and immune development. We measured cell-mediated immu...
Endler (1980) suggested that in a carotenoid-poor envi-ronment, carotenoid-dependent sexual ornamentsindicateforaging ability, and hence, they can be used by femalesto gauge male quality. This idea led researchers to viewfemale mate choice from a fresh perspective, and it gaineda fair level of acceptance (Kodric-Brown 1989; Milinskiand Bakker 1990;...
Comparing CURRENT sex ratios of people in national science academies with CURRENT sex ratios of emerging Ph.D.s says nothing about sexual discrimination. Why? Emerging Ph.D.'s do not immediately get elected ot their national academies. It is unlikely that academia is the only field of human endeavour free of sexism and racism, but that is no excuse...
Age-related increases in reproductive success could be the result of better survival by successful breeders (survival hypothesis), greater dispersal by unsuccessful breeders (dispersal hypothesis), and/or age-related differences in the ability to compete for breeding opportunities (constraint hypothesis). We used banding and nesting data from four...
Along with competition and predation, parasitism is one of the main sources of biotic stress facing all organisms. Recently, it has become recognized that animal diets may also be shaped by the need for protection from parasites. Foraging behavior evolves primarily to meet the need of a nutritionally adequate diet. However, just as foraging behavio...
Theoretical models view biparental care as a state of equilibrium that can be maintained only when the amount of parental care provided by one parent depends on the amount provided by its mate. According to these models, biparental care results when a decrease in the contribution of one parent is partially, but not completely, compensated for by an...
Although interspecific brood adoption has been reported in several species of birds, the process by which it occurs has seldom been reported. We observed a pair of Song Sparrows (Melospiza melodia) that adopted a brood of Yellow Warblers (Dendroica petechia) and, gradually, over several days, took over the parental duties of the original parents. D...
It has been argued that intraspecific mate-choice copying can be adaptive under certain conditions. Dugatkin’s (1992,Am. Nat.139, 1384–1389) work with guppies,Poecilia reticulataremains the most influential experimental demonstration of this phenomenon. We replicated Dugatkin's work using several choice criteria to ensure that our results were not...
We relate features of the breeding dispersions and site fidelity of American redstarts (Setaphaga ruticilla) to breeding success and interpret the findings in terms of sexual selection. One-year-old male redstarts show delayed plumage maturation, making male dispersions particularly easy to appreciate. In our study site in New Brunswick, Canada, ol...
We tested whether the age-related differences in reproductive success in male American Redstarts are caused by differences in date of arrival on the breeding grounds. By relating arrival date to three measures of reproductive success we determined what stage of the breeding cycle is affected by date of arrival. Adult male redstarts were more succes...
Using morphological or behavioural features correlated with paternal care, females can, prior to mating, assess the potential parental contribution of males; As a first step in a study of female mate choice in yellow warblers, this study was designed to examine the importance of paternal care by males of differing chest striping. Contrary to a prev...
DPM hypotheses are based on the assumption that older individuals are competitive superior. Blue and brown females did not differ in their parental abilities, but blue ones were larger and, after accounting for size differences, heavier and in better nutritional condition than brown females. Blue plumage is therefore an honest signal of condition.
beta-carotene has antioxidant and immunostimulant effects that so far have not been considered in the study of sexual selection. A trade-off is expeted between use of carotenoids for health and for displays.
Male tree swallow (Tachycineta bicolor) territory owners and floaters were compared in terms of size and nutritional condition to test the resource holding potential hypothesis. Owners were larger than floaters when compared using six morphological measurements. There were no differences in dry mass, ash, or fat content, but territory owners were h...
The role of parasitism has, to date, been largely ignored in optimal foraging theory. The mechanisms necessary to allow animals to use their diet to protect themselves from potential or actual parasitism have been observed in various species. The inclusion of the effects of parasitism on diet choice may considerably improve the predictive powers of...
In this thesis my initial goal was to use yellow warblers to examine the effect of paternal care on female mate choice. I first examined whether mate choice based on paternal care could be considered adaptive. Paternal care was variable among males and important to female fitness, but, contrary to a previous report, male chest striping could not be...