Perisoreus Canadensis Research Articles

"The Canada Jay: the National Bird of Canada?" by David Bird, Dan Strickland, Ryan Norris, Alain Goulet, Aaron Kylie, Mark Nadjiwan, Michel Gosselin, and Colleen Archer, foreword by Robert Bateman, 2022 [book review]

"The Canada Jay: the National Bird of Canada?" by David Bird, Dan Strickland, Ryan Norris, Alain Goulet, Aaron Kylie, Mark Nadjiwan, Michel Gosselin, and Colleen Archer, foreword by Robert Bateman, 2022 [book review]

Fecal DNA metabarcoding helps characterize the Canada jay's diet and confirms its reliance on stored food for winter survival and breeding.

Accurately determining the diet of wild animals can be challenging if food items are small, visible only briefly, or rendered visually unidentifiable in the digestive system. In some food caching species, an additional challenge is determining whether consumed diet items have been previously stored or are fresh. The Canada jay (Perisoreus canadensis) is a generalist resident of North American boreal and subalpine forests with anatomical and behavioural adaptations allowing it to make thousands of arboreal food caches in summer and fall that are presumably responsible for its high winter survival and late winter/early spring breeding. We used DNA fecal metabarcoding to obtain novel information on nestling diets and compiled a dataset of 662 published and unpublished direct observations or stomach contents identifications of natural foods consumed by Canada jays throughout the year. We then used detailed natural history information to make informed decisions on whether each item identified to species in the diets of winter adults and nestlings was best characterized as 'likely cached', 'likely fresh' (i.e., was available as a non-cached item when it appeared in a jay's feces or stomach), or 'either possible'. Of the 87 food items consumed by adults in the winter, 39% were classified as 'likely cached' and 6% were deemed to be 'likely fresh'. For nestlings, 29% of 125 food items identified to species were 'likely cached' and 38% were 'likely fresh'. Our results support both the indispensability of cached food for Canada jay winter survival and previous suggestions that cached food is important for late winter/early spring breeding. Our work highlights the value of combining metabarcoding, stomach contents analysis, and direct observations to determine the cached vs. non-cached origins of consumed food items and the identity of food caches, some of which could be especially vulnerable to degradation through climate change.

Survival throughout the annual cycle of first year Canada Jays in the context of sibling competition, expulsion, and adoption

Abstract For most birds that exhibit delayed dispersal (remaining on the natal territory rather than dispersing to seek a breeding opportunity), siblings appear free to stay or leave the natal area. However, in rare cases, delaying dispersal is determined via conflict among siblings, with the dominant individual remaining on the natal territory. We used radio-tracking to examine brood reduction, and subsequent juvenile survival, of first-year Canada Jays (Perisoreus canadensis) in Algonquin Provincial Park, Ontario, Canada. Soon after juveniles become nutritionally independent, intra-brood struggles lead to one “dominant juvenile” remaining on the natal territory after permanently expelling the subordinate siblings (“ejectees”). Males in above-average condition when nestlings were the most likely to become the dominant juveniles and females did so only when broods were all-female at the time of the expulsion. Dominant juveniles were much more likely to survive their first summer compared to ejectees (survival probabilities = 0.84 and 0.45, respectively), suggesting that ejectees are especially vulnerable to mortality risk in the critical interval between their expulsion from the natal territory and their settlement on a new territory. However, if ejectees lived to autumn, they had only a slightly lower probability of first-winter survival (0.73) than dominant juveniles (0.85). These results suggest that the survival advantage gained by dominant juveniles is greatest during the first summer after hatching, with a much smaller difference over the first winter after ejectees have settled on non-natal territories. Our work provides insight into potential evolutionary and ecological mechanisms driving social dominance hierarchies in wild birds.

Habitat and climate influence hybridization among three genetically distinct Canada jay (Perisoreus canadensis) morphotypes in an avian hybrid zone complex.

Examining the frequency and distribution of hybrids across contact zones provide insights into the factors mediating hybridization. In this study, we examined the effect of habitat and climate on hybridization patterns for three phenotypically, genetically, and ecologically distinct groups of the Canada jay (Perisoreus canadensis) in a secondary contact zone in western North America. Additionally, we tested whether the frequency of hybridization involving the three groups (referred to as Boreal, Pacific and Rocky Mountain morphotypes) is similar across the hybrid zones or whether some pairs have hybridized more frequently than others. We reanalyzed microsatellite, mtDNA and plumage data, and new microsatellite and plumage data for 526 individuals to identify putative genetic and phenotypic hybrids. The genetically and phenotypically distinct groups are associated with different habitats and occupy distinct climate niches across the contact zone. Most putative genetic hybrids (86%) had Rocky Mountain ancestry. Hybrids were observed most commonly in intermediate climate niches and in habitats where Engelmann spruce (Picea engelmannii) overlaps broadly with boreal and subalpine tree species. Our finding that hybrids occupy intermediate climate niches relative to parental morphotypes matches patterns for other plant and animal species found in this region. This study demonstrates how habitat and climate influence hybridization patterns in areas of secondary contact and adds to the growing body of research on tri-species hybrid zones.

Early-life sibling conflict in Canada jays has lifetime fitness consequences.

While delaying natal dispersal can provide short-term benefits for juveniles, lifetime fitness consequences are rarely assessed. Furthermore, competition for limited positions on a natal territory could impose an indirect fitness cost on the winner if the outcome has negative effects on its siblings. We use radio-tracking and 58 years of nesting data in Ontario, Canada to examine the lifetime fitness consequences of sibling expulsion in the Canada jay (Perisoreus canadensis). Six weeks after fledging, intra-brood dominance struggles result in one 'dominant juvenile' (DJ) remaining on the natal territory after expelling its subordinate siblings, the 'ejectees' (EJs). Despite an older age-at-first-reproduction, DJs produced more recruits over their lifetime and had higher first-year survival than EJs, leading to substantially higher direct fitness. Even though DJs incurred an indirect fitness cost by expelling their siblings and there was no evidence that their presence on the natal territory increased their parents' reproductive output the following year, they still had substantially higher inclusive fitness than EJs. Our results demonstrate how early-life sibling conflict can have lifetime consequences and that such fitness differences in Canada jays are driven by the enhanced first-year survival of DJs pursuant to the early-summer expulsion of their sibling competitors.

Habitat preferences of adult Canada Jays (Perisoreus canadensis) during the post-breeding period in Algonquin Provincial Park, Ontario, Canada

Habitat preferences in animals are often examined during the breeding period when individuals are easier to observe. However, habitat use may change once young become independent and if resource availability shifts with seasonality. While Canada Jays ( Perisoreus canadensis (Linnaeus, 1766)) in Algonquin Provincial Park, Ontario, Canada, have been studied for several decades, there is no information on habitat use outside of the fall and late-winter nesting period, where they primarily used conifer forests. Using radio telemetry and resource selection functions comparing used versus available habitats, we estimated home-range size and habitat preferences of 12 adult Canada Jays ( n = 334 locations) in the spring and summer. Mean (±SD) home-range size from minimum convex polygons was 84 (±48 ha) and ranged from 35 to 201 ha. Canada Jays strongly preferred forest–wetland edges, showed a weak preference for coniferous forests, a corresponding weak avoidance of shade-tolerant hardwood forests, and used mixed forest and wetlands in proportion to their availability. Our results suggest that, while adult Canada Jays use multiple types of habitat during the post-breeding period, they also key into forest–wetland edges, likely to take advantage of emergent prey while remaining near forested areas to maximize protection from predators.

Canada jays (Perisoreus canadensis) identify and exploit coniferous cache locations using visual cues

AbstractFood caching is a foraging strategy used by many vertebrates, involving the storage and subsequent recovery of food items for later consumption, when other food sources are scarce. Once cached, stored food, particularly highly perishable items, can degrade over time. Evidence suggests that for birds, some conifers may aid in cache preservation through protective properties in resin. However, due to the challenges involved with following birds to their caching locations, cache‐site preferences are not easily studied in the wild. We investigated eight captive Canada jays’ (Perisoreus canadensis) ability to both identify and exploit conifer tree species. Further, we examined potential cues that birds may use to identify and select these potentially beneficial sites. We found strong evidence to suggest that birds can quickly identify conifer tree species and subsequently exploit those cache locations preferentially. Furthermore, our evidence suggests that although birds do not appear to use olfactory cues when making caching decisions, they potentially to attend to structural cues. We suggest that visual information is essential to both the identification of conifer trees and to cache‐site selection decisions. These findings indicate that jays make rapid, fine scale assessments of their environments, discriminating amongst trees of different species and use this information to select cache‐sites.

An observational analysis of Canada Jay (Perisoreus canadensis) foraging and caching ecology in Denali National Park and Preserve, Alaska, USA

Arctic and subarctic wildlife are among the most vulnerable species to climate change. Canada Jays (Perisoreus canadensis (Linnaeus, 1776)) are generalist residents of northern boreal forests and scatter-hoard food to insulate against food scarcity during winter. Unlike most scatter-hoarders, however, Canada Jays primarily cache perishable food, rendering their caches more susceptible to climate change induced degradation and loss. Here we use a mostly noninvasive approach to document Canada Jay foraging ecology among a population in interior Alaska, USA, including the types of food acquired, foraging and caching rates, and cache longevity and loss. We also tested for associations between foraging and caching rates with reproductive metrics to assess possible relationships among food and productivity. We found that Canada Jays have a varied diet that changed seasonally, and responded to a record-setting warm spring by directing foraging efforts away from cache recovery and towards the emergence of fresh food. We did not find evidence for relationships between foraging and caching rate with reproductive output, possibly owing to small sample sizes. We found that caches were recovered quickly (<4 weeks) and frequently lost to conspecific and heterospecific competitors. Our study suggests that Canada Jays may be better poised to respond to changes in cache integrity and food availability than has been previously recognized.

Canada jays (Perisoreus canadensis) balance protein and energy targets simultaneously in both consumed and cached food

Food scarce periods pose serious physiological challenges for birds, especially in energetically demanding conditions. For species in the northern hemisphere, a decrease in available resources during winter adds further physiological stress to the energetic demands of life at low temperatures. Some species cache food to provide a reliable energy and nutrient resource during scarcity. Canada Jays are a year-round food-caching resident of the North American boreal forest. Canada Jays also rear their young prior to spring green up, making food caching not only essential for adult winter survival, but also potentially important for meeting the requirements of growing offspring in late winter and early spring. We examined the diet choices of Canada Jays immediately prior to winter, and the macronutrient composition of the foods Canada Jay consumed and cached at this time. We found that Canada Jays cache the same relative amounts of macronutrients as they consume but did not vary macronutrients seasonally. The similarities in the macronutrient proportions cached and consumed suggest a consistent nutrient intake pattern, and that Canada Jays are foraging to simultaneously meet similar minimum energy and minimum protein targets for both the present and future. These simultaneous targets constrain the caching decisions of jays when presented with dietary choices.

Early-life experience shapes patterns of senescence in a food-caching passerine.

For many species, breeding performance increases through early adulthood followed by declines later in life. Although patterns of age-specific decline have been shown to vary between individuals, the factors that lead to this individual variation in the intensity of reproductive senescence are yet to be fully understood. We investigated whether early-life social status influenced age-related trends in the breeding performance of male Canada jays (Perisoreus canadensis), year-round residents of North America's boreal and sub-alpine forests. Shortly after young become nutritionally independent, intra-brood dominance struggles lead to one juvenile (Dominant Juvenile) remaining on the natal territory after expelling its subordinate siblings (Ejectees). First, we show via radio tracking that in our declining range-edge population Ejectees either join an unrelated pair (67%), form a breeding pair with another bird (28%) or occupy a territory alone (5%). Second, using 39 years of breeding data, we demonstrate that Ejectee males advanced laying dates and increased the annual number of nestlings until 6 years of age before declining, whereas Dominant Juvenile males advanced laying dates until 11 years and increased annual number of nestlings until 12 years of age before declining. This study documents clear variation in ageing patterns between dominant and expelled young, with implications for the role of early-life experiences and phenotypic quality in determining patterns of ageing.

No evidence for future planning in Canada jays (Perisoreus canadensis).

In the past 20 years, research in animal cognition has challenged the belief that complex cognitive processes are uniquely human. At the forefront of these challenges has been research on mental time travel and future planning in jays. We tested whether Canada jays (Perisoreus canadensis) demonstrated future planning, using a procedure that has produced evidence of future planning in California scrub-jays. Future planning in this procedure is caching in locations where the bird will predictably experience a lack of food in the future. Canada jays showed no evidence of future planning in this sense and instead cached in the location where food was usually available, opposite to the behaviour described for California scrub-jays. We provide potential explanations for these differing results adding to the recent debates about the role of complex cognition in corvid caching strategies.

Investigating factors that set the lower elevational limit of Canada Jays (Perisoreus canadensis) on Vancouver Island, British Columbia, Canada

The biotic and abiotic factors responsible for determining ranges of most species are poorly understood. The Canada Jay (Perisoreus canadensis (Linnaeus, 1766)) relies on perishable cached food for over-winter survival and late-winter breeding and the persistence of cached food could be a driver of range limits. We confirmed that the Canada Jay’s lower elevational limit on Vancouver Island, British Columbia, Canada, matches that of the subalpine zone (900 m) and then conducted simulated caching experiments to examine the influence of antimicrobial properties of subalpine tree species (biotic) and of temperature (abiotic) on the preservation of cached food. We found that two high-elevation species, yellow cedar (Callitropsis nootkatensis (D. Don) D.P. Little) and Amabilis fir (Abies amabilis Douglas ex J. Forbes), preserved cached blueberries and chicken flesh better than other trees, but they also occurred well below the lower limit of Canada Jays. The effect of temperature was similarly unclear; while food cached at 1150 m retained 17% more mass than food cached at 550 m, there was no difference in percent mass remaining of food placed 70 m above versus 120 m below the Canada Jay’s lower elevational limit. Thus, we were unable to provide definitive evidence that either of the proposed abiotic or biotic factors was responsible for setting thelower elevational limit of resident Canada Jays.

Patterns and causes of breeding dispersal in a declining population of Canada jays, Perisoreus canadensis, over 55 years

Breeding dispersal can influence fitness as well as the dynamics and genetic architecture of populations, but the patterns and causes of dispersal in most species are still poorly understood. Here, we used 55 years of re-sighting and breeding data from 530 individually marked adult Canada jays at the southern edge of their range in Algonquin Provincial Park, Ontario, Canada to evaluate factors that influence the probability of breeding dispersal occurrences and distances. Breeding dispersal within the study area was rare, occurring in 3% ( N = 81) of the 2477 cases in which individuals were observed defending a territory in consecutive years, and only 13% ( N = 68) of individuals dispersed at least once in their lifetime (mean age of dispersers = 4.75 ± 2.8). Of the 81 breeding dispersal cases, 68% ( N = 55) involved a single bird, while the remaining 32% ( N = 26) involved 13 cases of a mated pair dispersing together. The probability of breeding dispersal was similar between sexes, but females tended to disperse farther. Surprisingly, almost half of breeding dispersal events occurred during the autumn and winter when all or most food had already been cached. However, 70% ( N = 57) of breeding dispersal events involved settlement on a neighbouring territory, which may have allowed adults to retrieve previously cached food on their original territory. Overall, adults were most likely to disperse locally when they lost a mate, had originally occupied a lower-quality territory, and a vacant position was available nearby. While the distance and rates of breeding dispersal did not change over time ( N = 55), breeding dispersal events caused by mate loss, were highest in years with the steepest population decline, suggesting that a diminishing pool of mate replacements influenced breeding dispersal decisions. • We investigated factors influencing breeding dispersal in Canada jays. • Breeding dispersal was uncommon, occurring in 3% of breeding events. • Individuals usually dispersed to neighbouring territories, near previous caches. • Adult were more likely to disperse locally after experiencing mate loss. • Dispersal from mate loss was highest when population decline was most pronounced.

Canada jays, Perisoreus canadensis, use multiple context-dependent cache protection strategies

Food caching is a behaviour used by a variety of birds and mammals and can be an essential strategy for surviving food-scarce periods. Ensuring that cached food remains available for later recovery is critical to the fitness of caching individuals. Cache robbers, conspecific or heterospecific individuals that remove and consume food stored by the original cacher, present a unique threat to food-caching individuals. Accordingly, caching species have evolved a variety of cache protection strategies to limit the potential risk of cache robbery. We assessed these cache protection strategies in Canada jays, year-round residents of Canada and the western United States that rely on cached food to survive food-scarce winters. We evaluated caching behaviour and movement patterns of captive Canada jays in caching contexts that varied in potential risk of cache robbing: presence versus absence of a model cache robber and visual cover from the cache robber. We found that depending on perceived risk, Canada jays flexibly used a variety of nonmutually exclusive cache protection strategies including cache depression, out-of-sight caching and spacing. These cache protection strategies likely reduce the risk of cache robbing and increase the probability of caches remaining available for recovery and consumption. • Canada jays used quantity-based and location-based cache protection strategies. • Cache protection strategies were modulated by potential cache-robbing threats. • Visual information was prioritized in cache protection and cache site selection.

Breeding dispersal in a resident boreal passerine can lead to short‐ and long‐term fitness benefits

AbstractWhether an individual disperses or remains site‐faithful between breeding seasons can have important impacts on individual fitness and population dynamics. While several studies have identified factors influencing the probability of breeding dispersal, the consequences of dispersal are much less certain, particularly over an individual’s lifetime. Here, we use 81 cases (13 paired and 55 single dispersals) of breeding dispersal across 55 yr of breeding and re‐sighting data from an individually marked population of Canada jays (Perisoreus canadensis) at the southern edge of their range in Algonquin Provincial Park, Ontario to determine both the short‐ (year after dispersal) and long‐term (lifetime) consequences of breeding dispersal. In the year following dispersal, adults had larger brood sizes and higher nest success compared to the year prior to dispersal. However, when adults dispersed during the fall/winter, they had significantly later lay dates and lower rates of nest success than adults that dispersed during the summer. Additionally, most breeders dispersed to territories of higher quality and individuals that dispersed to a territory of lesser quality experienced lower rates of nest success. Importantly, individuals that dispersed at least once in their lifetime produced an average of 2.7 more young and recruited an average of 0.9 more juveniles into the population compared to individuals that remained site‐faithful. Our study provides rare evidence of both the short‐ and long‐term benefits of breeding dispersal in Canada jays and demonstrates how the timing of dispersal can also have consequences for individual reproductive performance.

Early-Life Corticosterone Body Condition Influence Social Status and Survival in a Food-Caching Passerine.

Individuals undergo profound changes throughout their early life as they grow and transition between life-history stages. As a result, the conditions that individuals experience during development can have both immediate and lasting effects on their physiology, behavior, and, ultimately, fitness. In a population of Canada jays in Algonquin Provincial Park, Ontario, Canada, we characterized the diet composition and physiological profile of young jays at three key time points during development (nestling, pre-fledge, and pre-dispersal) by quantifying stable-carbon (δ13C) and -nitrogen (δ15N) isotopes and corticosterone concentrations in feathers. We then investigated the downstream effects of early-life diet composition, feather corticosterone, and environmental conditions on a juvenile's social status, body condition, and probability of being observed in the fall following hatch. Across the three time points, the diet of Canada jay young was composed primarily of vertebrate tissue and human food with the proportion of these food items increasing as the jays neared dispersal. Feather corticosterone concentrations also shifted across the three time points, decreasing from nestling to pre-dispersal. Dominant juveniles had elevated corticosterone concentrations in their feathers grown pre-dispersal compared with subordinates. High body condition as nestlings was associated with high body condition as juveniles and an increased probability of being observed in the fall. Together, our results demonstrate that nestling physiology and body condition influence the social status and body condition once individuals are independent, with potential long-term consequences on survival and fitness.

A bird that changes colour without moulting: how the wîskicâhk (Canada Jay, Perisoreus canadensis) tricked the taxonomists

Avian and mammalian colours are thought to be constant in life and in museum specimens, but several early 20th-century taxonomists singled out the Canada Jay (Perisoreus canadensis (Linnaeus, 1766)) as having unstable feather pigments and warned against using old museum specimens for taxonomic purposes. One such error was Brisson’s (1760) original naming of the species as “the Brown Jay of Canada”. Another was Ridgway’s (1899) naming of the “Gray Jay” as a new subspecies, Perisoreus (canadensis) griseus, through inappropriate comparison of fresh grey specimens with old brown ones. We discovered that browning of initially grey plumage also occurs between annual moults in living individuals of the Canada Jay’s Pacific morphotype. We documented this change using photographs and re-sightings of colour-banded individuals and through spectral analysis of year-old (brown) and incoming (grey) rectrices collected from the same moulting individuals. To assess the distribution of this colour change, we compared September vs. May eBird photographs from across North America. We showed that seasonal colour change is normal in the Pacific morphotype but rare in the two other morphotypes. Collectively, these data have important implications for the taxonomy of the Canada Jay and are a cautionary tale for taxonomists studying animal colouration.

Cryptic genetic diversity and cytonuclear discordance characterize contact among Canada jay (Perisoreus canadensis) morphotypes in western North America

AbstractThree distinct Canada jay (Perisoreus canadensis) morphotypes with easily recognizable plumage traits come into contact in western North America. Recent work demonstrated high genetic structure across the species’ range; however, patterns of genetic variation in these contact zones remain unknown. We categorized 605 individuals into one of three morphotypes (Pacific, Rocky Mountain, and Boreal) based on plumage, and genotyped individuals at the mtDNA control region and 12 microsatellite loci to assess the extent of hybridization between morphotypes. Our data showed cryptic genetic diversity and high cytonuclear discordance among morphotypes within contact zones, which is likely the result of recent and historical admixture. The distributions of the Boreal and Pacific morphotypes each showed a strong association with a single, distinct genetic group, whereas the Rocky Mountain morphotype exhibited higher genetic diversity and was associated with multiple genotypes. Our analyses show the importance of considering both plumage and genetic traits when examining contact zones between closely related taxa. Finally the data presented in this study reaffirm that the Pacific morphotype is distinct from the Boreal and Rocky Mountain morphotypes based on genetic, phenotypic and ecological data, indicating that the Pacific morphotype should be re-elevated to a full species.

Causes and consequences of variation in diet composition of nestling Canada jays

Diet quality during development can impact growth, physiology, behaviour and survival. The Canada jay is a resident boreal passerine that caches a wide variety of perishable food items in late summer and autumn for its over‐winter survival and late‐winter reproduction. A previous experiment found evidence that food supplementation of Canada jay pairs during the nestling period had a positive effect on the condition of their nestlings. However, given that foods cached by adults vary widely in nutritional content, the composition of nestling diets could also have an important influence on offspring development. In a population of Canada jays in Algonquin Provincial Park, Ontario, Canada, we investigated the influence of environmental conditions before and during the breeding season on nestling diet composition and the consequences of nestling diet composition on the body condition of nestlings and on their subsequent survival. Using stable‐carbon (δ13C) and ‐nitrogen (δ15N) isotopes, we estimated the proportion of three food groups (vertebrates + human food, invertebrates and plants) in feathers from almost 200 nestlings. Nestling diet in March and April was influenced by environmental conditions 5–6 months prior to hatching, with warmer and more variable autumn temperatures associated with a greater proportion of vertebrate flesh and human food in the diet. However, the proportion of vertebrates and human food in the diet had no influence on nestling body condition or whether an individual was observed the following fall. Our results, in conjunction with previous work on Canada jays, suggest that the quantity of food available to a nestling during development may be more important than diet composition.

Climate-driven carry-over effects negatively influence population growth rate in a food-caching boreal passerine.

Understanding how events throughout the annual cycle are linked is important for predicting variation in individual fitness, but whether and how carry-over effects scale up to influence population dynamics is poorly understood. Using 38years of demographic data from Algonquin Provincial Park, Ontario, and a full annual cycle integrated population model, we examined the influence of environmental conditions and density on the population growth rate of Canada jays (Perisoreus canadensis), a resident boreal passerine that relies on perishable cached food for over-winter survival and late-winter breeding. Our results demonstrate that fall environmental variables, most notably the number of freeze-thaw events, carried over to influence late-winter fecundity, which, in turn, was the main vital rate driving population growth. These results are consistent with the hypothesis that warmer and more variable fall conditions accelerate the degradation of perishable stored food that is relied upon for successful reproduction. Future warming during the fall and winter may compromise the viability of cached food that requires consistent subzero temperatures for effective preservation, potentially exacerbating climate-driven carry-over effects that impact long-term population dynamics.