Jean-François Giroux

University of Quebec in Montreal | UQAM · Department of Biological Sciences

In 2022, a severe outbreak of disease caused by clade 2.3.4.4b Highly Pathogenic Avian Influenza (HPAI) H5N1 virus resulted in unprecedented mortality among wild birds in eastern Canada. Tens of thousands of birds were reported sick or dead, prompting a comprehensive assessment of mortality spanning the breeding season between April 1 and September...

Indigenous-driven and community-partnered research projects seeking to develop salient, legitimate, and credible knowledge bases for environmental decision-making require a multiple knowledge systems approach. When involving partners in addition to communities, diverging perspectives and priorities may arise, making the pathways to engaging in prin...

H5N1 clade 2.3.4.4b viruses have caused significant mortality events in various wild bird species across Europe, North America, South America, and Africa. In North America, the largest impacts on wild birds have been in eastern Canada, where over 40,391 wild birds were reported to have died from highly pathogenic avian influenza (HPAI) between Apri...

In 2022, a severe outbreak of clade 2.3.4.4b Highly Pathogenic Avian Influenza (HPAI) H5N1 virus resulted in unprecedented mortality among wild birds in eastern Canada. Tens of thousands of birds were reported sick or dead, prompting a comprehensive assessment of mortality spanning the breeding season between April 1 and September 30, 2022. Mortali...

Numbers of temperate‐breeding Atlantic and Mississippi Flyway Canada geese have greatly increased since the 1980s. Consequently, numbers of yearlings, sub‐adults and failed breeders undertaking pre‐molt migration to northern latitudes has also increased, potentially providing additional hunting opportunities for Cree hunters living near James Bay,...

Urban-adapted gulls can be exposed to flame retardants while foraging in landfills where elevated concentrations of polybrominated diphenyl ethers (PBDEs) and other halogenated flame retardants (HFRs) have frequently been measured in air. However, the contribution of atmospheric exposure has largely been overlooked compared to dietary exposure in b...

Canada Geese (Branta canadensis) are an important wildlife food resource for Cree people living in communities along the James Bay coasts. According to Traditional Ecological Knowledge, environmental changes along the coast have affected hunting success. Also, changes in the relative abundance of different goose populations that use James Bay may a...

Sound management of bird populations rests upon an adequate understanding of their population dynamics. Our study evaluated recruitment and population growth rates of 14 American common eider (Somateria mollissima dresseri) colonies from Labrador, Nova Scotia, Quebec, Canada, and Maine, USA, during various periods between 1970 and 2019. We used Pra...

After successful conservation and management efforts throughout much of the twentieth century that led to the recovery of common eiders (Somateria mollissima) breeding in several jurisdictions in eastern North America, their abundance has declined in recent years, probably linked to various environmental stressors. To evaluate where to focus future...

Several bird species have adapted to foraging in landfills, although these sites are known to represent significant sources of emissions of toxic semi-volatile chemicals including the halogenated flame retardants (HFRs) (e.g., polybrominated diphenyl ethers (PBDEs) and emerging compounds). The objective of this study was to investigate the associat...

Landfills represent important sources of local emissions of organic contaminants, including halogenated (HFR) and organophosphate ester (OPE) flame retardants used in a large variety of consumer products. Gulls foraging in landfills may be exposed to elevated atmospheric concentrations of HFRs and OPEs that may vary spatially and temporally within...

Halogenated flame retardants (HFRs) are contaminants that are abundantly emitted from waste management facilities (WMFs) and that became ubiquitous in air of urbanized regions. Urban birds including gulls have adapted to exploiting human food resources (refuse) in WMFs, and have thus experienced population explosions worldwide. However, foraging in...

Individuals consistently differ in their behavior, and such personality differences are often linked to fitness. For biparental care species, the behavior of both parents can impact reproductive success. Behavioral similarity within pairs has been shown to provide selective advantages for many species. In this study, we tested for behavioral simila...

Animals are thought to adjust the intensity of their parental defense to fitness benefits associated with their current reproduction. They should be more defensive when they breed early in the season, when they produce more young, or as their young get older. Beyond these plastic changes, associations among traits could be explained by consistent a...

Among the numerous demographic parameters that influence population size, unbiased estimates of pre-fledging survival remain difficult to obtain for precocial birds. In this study, we used capture–mark–recapture modeling to estimate pre-fledging survival in a population of temperate-nesting Canada geese Branta canadensis maxima that has undergone a...

Food hoarding is often considered an adaptive behaviour to extend the period of availability of food resources. Finding the right caching site for storage and retrieval is of paramount importance, yet how caching sites are selected is poorly known. Here, we examine site selection for egg caching by a tundra predator, the arctic fox, Vulpes lagopus,...

Birds have been used intensively as biomonitors of halogenated flame retardants (HFRs), and several studies have reported elevated tissue concentrations and inter-individual variability for these contaminants. While diet is known to be an important exposure pathway for HFRs in birds, it has been suggested that exposure through air may represent an...

Between the early 1900s and the 1990s, the greater snow goose Anser caerulescens atlanticus population grew from 3000 individuals to more than 700 000. Because of concerns about Arctic degradation of natural habitats through overgrazing, a working group recommended the stabilization of the population. Declared overabundant in 1998, special manageme...

Le transport atmosphérique des retardateurs de flamme halogénés (RFH) est aujourd’hui bien documenté (Csizar et al., 2014; Abassi et al., 2015). D’abord ajoutés à une multitude de produits de consommation pour répondre aux normes de sécurité incendie, les RFH migrent continuellement depuis leurs supports initiaux vers l’atmosphère. Considérant l’ef...

Understanding how birds cope with climate change has received much attention in recent years. So far, more emphasis has been given to passerine species than to any other groups of birds, possibly because of the availability of long-term data sets. Our objective was to study the effect of climate change on spring arrival date and breeding chronology...

Ring-billed Gulls (Larus delawarensis) were rare at the beginning of the 20th century, possibly because of intensive exploitation. Once they became protected in 1916, their numbers increased throughout eastern North America, reaching a maximum of 875,000 breeding pairs around 1990. Since then, an overall decline of 19% has been recorded in the Grea...

Gulls are commonly attracted to landfills, and managers are often required to implement cost-effective and socially accepted deterrence programs. Our objective was to evaluate the effectiveness of an intensive program that integrated the use of trained birds of prey, pyrotechnics, and playback of gull distress calls at a landfill located close to a...

Environmental and behavioral factors have long been assumed to affect variation in avian field metabolic rate (FMR). However, due to the difficulties in measuring continuous behavior of birds over prolonged periods of time, complete time-activity budgets have rarely been examined in relation to FMR. Our objective was to determine the effect of acti...

Differences in feeding ecology are now recognized as major determinants of inter-individual variations in contaminant profiles of free-ranging animals, but exceedingly little attention has been devoted to the role of habitat use. Marked inter-individual variations and high levels of polybrominated diphenyl ethers (PBDEs) (e.g., DecaBDE) have previo...

Foraging animals are influenced by the distribution of food resources and predation risk that both vary in space and time. These constraints likely shape trade-offs involving time, energy, nutrition, and predator avoidance leading to a sequence of locations visited by individuals. According to the marginal-value theorem (MVT), a central-place forag...

The aim of the present study was to investigate the feeding ecology of an omnivorous bird, the Ring-billed Gull (Larus delawarensis Ord, 1815), breeding in a highly urbanized and heterogeneous landscape (Montréal area, Quebec, Canada). We used gastrointestinal (G.I.) tract content analysis, GPS-based tracking information, and stable isotope profile...

Landfill managers often need to implement scaring programmes to deter gulls from feeding at their sites because the birds can be a significant nuisance for both site employees and residents of the surrounding area. Our objective was to assess the efficiency of firing rubber shots, a method assumed to be non-lethal but never tested in a bird deterre...

During its spring and fall migrations, the Greater Snow Goose (Chen caerulescens atlanticus) stages in the marshes along the St. Lawrence Estuary in southern Quebec, where it feeds on three-square bulrush (Schoenoplectus americanus) rhizomes. The goose population has grown from 70 000 birds to around one million over the last 40 years, thus increas...

Bird colonies are potentially rich sources of social information that can be used to compensate for the numerous disadvantages of communal life. This information can reduce uncertainty about nest locations, mates or food sources. However, there is little empirical evidence that colonies can actually serve as an information exchange point. We asked...

Issue with landfills near airports • Feeding: population growth • Nuisance for residents of the surrounding area • Nuisance/health and safety for machinery operators• Increased risk for aircraft • Need for effective deterrence programs • Landfills: ideal study sites Objective: compare 2 deterrent programs • Falconry since 1995 by Falcon Environment...

The northern common eider (Somateria mollissima borealis) has become a source of concern because of recent declines and possible overharvest. Birds that breed in the Canadian mid-Arctic winter in both Greenland and Canada, but the wintering grounds of birds that breed farther south are unknown. Our objectives were thus to identify the molting and w...

Common eiders Somateria mollissima nest in colonies on islands of the St. Lawrence Estuary in Quebec, Canada. After hatching, attending females must reach suitable brood-rearing habitats while non-attending females and adult males must find appropriate moulting sites. The aim of our study was to determine the biotic and abiotic factors that influen...

We examined whether the fall activity budgets of greater snow geese (Chen caerulescens atlantica) vary between years and sites by comparing time-budget data gathered from 1982 to 1984 at the Montmagny and Cap-Saint-Ignace sanctuaries in Quebec. Feeding and resting accounted for more than 70% of the activities during the daylight period. At Cap-Sain...

I studied interspecific nest parasitism by redheads (Aythya americana) from 1976 to 1978 in a population of upland nesting ducks on artificial islands in southeastern Alberta. Of 685 duck nests, 19% were parasitized by redheads with a mean of 2.68 parasitic eggs per host nest. The proportion of nests parasitized increased with the density of host n...

We investigated whether repeated intensive grazing of rhizomes of three-square bulrush (Scirpus americanus) by greater snow geese (Chen caerulescens atlantica) staging in a tidal brackish marsh along the St. Lawrence River in Québec can induce changes in the nutritional value and structural characteristics of the rhizomes. We compared rhizomes grow...

Above- and below-ground standing crops as well as primary production of several macrophytes were estimated in Scirpus marshes along the south shore of the St. Lawrence River estuary in Quebec. Aboveground standing crop was measured by clipping vegetation, while belowground standing crop was estimated by soil coring. Seasonal variation of live and d...

Different methods to estimate primary production of Scirpus marshes of the St. Lawrence estuary were compared. Quadrats 25 × 25 cm and cores 10 cm in diameter were found to be the optimal size to sample above- and below-ground standing crops, respectively. Ash content for different plant parts of various species was measured to obtain more accurate...

When a communal roost is large relative to foraging distances, variance in foraging success may affect the positioning of the birds within the roost and we should expect fidelity to positions that improve foraging success. We explored fidelity of Snow Geese (Chen caerulescens) to three sections of a 5-km2 roost in flooded lowlands during their spri...

The influence of landscape structure on abundance or spacing patterns of generalist bird species may be nonlinear and vary annually depending on the severity of environmental conditions. The Eastern Wild Turkey (Meleagris gallopavo sylvestris) is a generalist forest species that experiences high mortality when snow reduces food availability. Althou...

Although water availability is primarily seen as a factor affecting food availability (a bottom-up process), we examined its effect on predator-prey interactions through an influence on prey behavior (a top-down process). We documented a link between water availability, predation risk, and reproductive success in a goose species (Chen caerulescens...

Nonrandom dispersal has been recently advanced as a mechanism promoting fine-scale genetic differentiation in resident populations, yet how this applies to species with high rates of dispersal is still unclear. Using a migratory species considered a classical example of male-biased dispersal (the greater snow goose, Chen caerulescens atlantica), we...

Food-caching by arctic foxes (Vulpes lagopus (L., 1758)) is a behavioural adaptation thought to increase winter survival, especially in bird colonies where a large number of eggs can be cached during a short nesting season. In this paper, we measured the energy content of greater snow goose (Chen caerulescens atlantica Kennard, 1927) eggs and evalu...

Above- and belowground biomass of the macrophyte Schoenoplectus maritimus was measured in Camargue (Rhône delta, southern France) using destructive and non-destructive sampling methods. Our aim was to validate whether non-destructive sampling could be used for long-term monitoring of marshes subjected to grazing by cattle and Greylag geese (Anser a...

Resource pulses are common in various ecosystems and often have large impacts on ecosystem functioning. Many animals hoard food during resource pulses, yet how this behaviour affects pulse diffusion through trophic levels is poorly known because of a lack of individual-based studies. Our objective was to examine how the hoarding behaviour of arctic...

1. Habitat heterogeneity and predator behaviour can strongly affect predator-prey interactions but these factors are rarely considered simultaneously, especially when systems encompass multiple predators and prey. 2. In the Arctic, greater snow geese Anser caerulescens atlanticus L. nest in two structurally different habitats: wetlands that form in...

Despite numerous studies on breeding dispersal, it is still unclear how habitat heterogeneity and previous nesting success interact to determine nest-site fidelity at various spatial scales. In this context, we investigated factors affecting breeding dispersal in greater snow geese (Anser caerulescens atlanticus), an Arctic breeding species nesting...

It has been thought for a long time that wetland plants were devoid of mycorrhizae. In recent years, however, an increasing number of studies have reported the presence of vesicular-arbuscular mycorrhizae (or endomycorrhizae) on several marsh plants. These fungi are often beneficial for their hosts enhancing growth through better mineral and water...

Resource pulses are common in various ecosystems and often have large impacts on ecosystem functioning. Many animals hoard food during resource pulses, yet how this behaviour affects pulse diffusion through trophic levels is poorly known because of a lack of individual-based studies. Our objective was to examine how the hoarding behaviour of arctic...

1. Habitat heterogeneity and predator behaviour can strongly affect predator-prey interactions but these factors are rarely considered simultaneously, especially when systems encompass multiple predators and prey.2. In the Arctic, greater snow geese Anser caerulescens atlanticus L. nest in two structurally different habitats: wetlands that form int...

No mycorrhizae on Schoenoplectus maritimus in the Camargue. — It has been thought for a long time that wetland plants were devoid of mycorrhizae. In recent years, however, an increasing number of studies have reported the presence of vesicular-arbuscular mycorrhizae (or endomycorrhizae) on several marsh plants. These fungi are often beneficial for...

Cache recovery is critical for evolution of hoarding behaviour, because the energy invested in caching may be lost if consumers other than the hoarders benefit from the cached food. By raiding food caches, animals may exploit the caching habits of others, that should respond by actively defending their caches. The arctic fox (Alopex lagopus) is the...

Food-hoarding animals are expected to preferentially cache items with lower perishability and/or higher consumption time. We observed arctic foxes (Alopex lagopus) foraging in a greater snow goose (Anser caerulescens atlanticus) colony where the main prey of foxes consisted of goose eggs, goslings, and lemmings (Lemmus and Dicrostonyx spp.). We rec...

Post-hatch brood movements to high-quality foraging sites are common in precocial birds but may entail costs for young. We assessed effects of overland movements of broods between the nesting and rearing areas in Greater Snow Geese (Chen caerulescens atlantica) breeding on Bylot Island, Nunavut, Canada, to determine whether these movements affected...

Post-hatch brood movements to high-quality foraging sites are common in precocial birds but may entail costs for young. We assessed effects of over-land movements of broods between the nesting and rearing areas in Greater Snow Geese (Chen caerulescens atlantica) breeding on Bylot Island, Nunavut, Canada, to determine whether these movements affecte...

Post-hatch brood movements to high-quality foraging sites are common in precocial birds but may entail costs for young. We assessed effects of overland movements of broods between the nesting and rearing areas in Greater Snow Geese (Chen caerulescens atlantica) breeding on Bylot Island, Nunavut, Canada, to determine whether these movements affected...

Many precocial birds make long-distance movements with their young after hatch to reach the best foraging sites. On Bylot Island, Nunavut, a large number of Greater Snow Goose (Chen caerulescens atlantica L., 1758) families move 30km from the main nesting colony (MNC) to reach the main brood-rearing area (MBR) soon after hatch. Geese moving from th...

Development of minimally invasive techniques to collect blood in free-living birds is desirable for both ethical and conservation reasons. We describe a new, simple technique for collecting blood samples from waterfowl eggs that involves recovering blood from a small hemorrhage after puncturing the shell of eggs showing the first signs of hatching....

Geese are large, herbivorous birds that graze in huge flocks in ways that may have a considerable impact on vegetation. This is exemplified best in two subspecies of snow geese, the lesser and the greater, both of which have increased dramatically in numbers in recent decades. In arctic coastal salt marshes, moderate goose grazing on Puccinellia ph...

Abdominal profile indices were developed to evaluate body condition in birds without capturing or handling them. We assessed the reliability of abdominal profile indices in predicting condition of spring staging Greater Snow Geese (Chen caerulescens atlantica). We first calibrated profile scores assigned to females against two direct measures of nu...

Abdominal profile indices were developed to evaluate body condition in birds without capturing or handling them. We assessed the reliability of abdominal profile indices in predicting condition of spring staging Greater Snow Geese (Chen caerulescens atlantica). We first calibrated profile scores assigned to females against two direct measures of nu...

The North American greater snow goose population has increased dramatically during the last 40 years. We evaluated whether refuge creation, changes in land use on the wintering and staging grounds, and climate warming have contributed to this expansion by affecting the distribution, habitat use, body condition, and migration phenology of birds. We...

In the northern hardwood forest of northeastern North America, ecological and social perceptions call for forest management systems using reduced-impact silviculture such as single-tree selection cutting and small clearcuts. When applied over large areas, single-tree selection cut and small clearcut systems are likely to generate different local ha...

Decisions made by birds during migration to breeding grounds can strongly affect the fitness of individuals. We investigated possible causes and reproductive consequences of inter-individual variation in the migratory behavior of an arctic-nesting species, the greater snow goose (Anser caerulescens atlanticus), by radio-tracking females at their st...

For many species, human‐induced disturbances can severely influence an individual's pay‐off; however, energy‐cost variations from different disturbance types have rarely been reported. We evaluated the dynamic behavioural responses of staging greater snow geese Anser caerulescens atlanticus to different types of disturbance in southern Quebec, Cana...

Accurate and precise estimation of the size of animal populations is critical to sound management and conservation. The size of the greater snow goose (Chen caerulescens atlantica) population has been monitored since 1965 by means of an aerial photographic survey conducted every spring in southern Quebec, Canada. As the population increased, the es...

Breeding propensity, defined as the probability that a sexually mature adult will breed in a given year, is an important determinant of annual productivity. It is also one of the least known demographic parameters in vertebrates. We studied the relationship between breeding propensity and conditions on spring staging areas (a spring conservation hu...

We examined the role of trophic interactions in structuring a high arctic tundra community characterized by a large breeding colony of greater snow geese (Chen caerulescens atlantica). According to the exploitation ecosystem hypothesis of Oksanen et al. (1981), food chains are controlled by top-down interactions. However, because the arctic primary...

A spring conservation hunt (15 Apr-31 May) to control the exponential population growth of greater snow geese (Chen caerulescens atlantica) was introduced in 1999 during their staging in southern Quebec, Canada. We tested the hypothesis that disturbance by hunting negatively affected nutrient storage in spring. We compared the amount of fat and pro...

There is growing evidence that harnesses may not be an effective technique to attach radio-transmitters on geese. The use of neck collars is an alternative, but studies on the effect of collars with or without radios on geese have reached divergent conclusions. As our objective was to determine if radio neck collars affect behaviour, pair bonds and...