Perisoreus canadensis



INTRODUCTORY


 

Terry Spivey, www.forestryimages.org


AUTHORSHIP AND CITATION:
Ulev, Elena D. 2006. Perisoreus canadensis. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). Available: http://www.fs.fed.us/database/feis/ (2007, January 16).

FEIS ABBREVIATION:
PECA

SYNONYMS:
None

COMMON NAMES:
gray jay
grey jay
Canada jay
whiskey Jack
camp robber

TAXONOMY:
Perisoreus canadensis (Linnaeus) is the scientific name for the gray jay, a member of the Corvidae family. Listed below are 11 recognized subspecies [4,60,104]:

Perisoreus canadensis albescens Peters
Perisoreus canadensis arcus Miller
Perisoreus canadensis barbouri Brooks
Perisoreus canadensis bicolor Miller
Perisoreus canadensis canadensis Linnaeus
Perisoreus canadensis capitalis Ridgway
Perisoreus canadensis griseus Ridgway
Perisoreus canadensis nigricapillus Ridgway
Perisoreus canadensis obscurus Ridgway
Perisoreus canadensis pacificus Gmelin
Perisoreus canadensis sanfordi Oberholser

ORDER:
Passeriformes

CLASS:
Bird

FEDERAL LEGAL STATUS:
No special status

OTHER STATUS:
Information on state-level protected status of animals in the United States is available at NatureServe, although recent changes in status may not be included.

WILDLIFE DISTRIBUTION AND OCCURRENCE

SPECIES: Perisoreus canadensis
GENERAL DISTRIBUTION:
The gray jay is a native resident from northern Alaska east to Newfoundland and Labrador and south to northern California, Idaho, Utah, east-central Arizona, north-central New Mexico, central Colorado, and southwestern South Dakota. It is also a native resident in northern Minnesota, northern Wisconsin, northern Michigan, northern New York, and northern New England. The gray jay may wander north of the breeding range. In winter it travels irregularly to northwestern Nebraska, central Minnesota, southeastern Wisconsin, central Michigan, southern Pennsylvania, central New York, Connecticut, and Massachusetts [3,4,113].

Perisoreus canadensis albescens is a resident from northeastern British Columbia and northwestern Alberta southeastward, east of the Rocky Mountains to South Dakota (Black Hills). It< is casual in northwestern Nebraska [3].

Perisoreus c. arcus is a resident in the Rainbow Mountains area, and headwaters of the Dean and Bella Coola Rivers of the central Coast Ranges, British Columbia [3].

Perisoreus c. barbouri is a resident on Anticosti Island, Quebec [3].

Perisoreus c. bicolor is a resident in southeastern British Columbia, southwestern Alberta, eastern Washington, northeastern Oregon, northern and central Idaho, and western Montana [3].

Perisoreus c. canadensis breeds from northern British Columbia east to Prince Edward Island, and south to northern Minnesota, northern Wisconsin, northern Michigan, northeastern New York, northern Vermont, northern New Hampshire, and Maine. It winters at lower altitudes within the breeding range and south to southern Ontario and Massachusetts, casually to central Minnesota, southeastern Wisconsin, northwestern Pennsylvania, and central New York. Perisoreus c. canadensis is accidental in northeastern Pennsylvania (Philadelphia) [3].

Perisoreus c. capitalis is a resident in the southern Rocky Mountains from eastern Idaho, central south-central Montana, and western and southern Wyoming south through eastern Utah, and western and central Colorado, to central eastern Arizona and north-central New Mexico [3].

Perisoreus c. griseus is a resident from southwestern British Columbia and Vancouver Island south through central Washington and central Oregon to the mountains of north-central and northeastern California [3].

Perisoreus c. nigracapillus is a resident in northern Quebec (Fort Chimo, Whale River, and George River), throughout Labrador, and in southeastern Quebec (Mingan and Blanc Sablon) [3].

Perisoreus c. obscurus is a resident in the coastal belt from Washington (Crescent Lake, Seattle, and Columbia River) through western Oregon to northwestern California (Humboldt County) [3].

Perisoreus c. pacificus is a resident in north-central Alaska (Kobuk River, Endicott Mountains, and Fort Yukon), northern Yukon (Arctic Circle at the International Boundary), and northwestern Mackenzie (Mackenzie Delta and lower Horton River) south in Alaska to latitude 60° N [3].

Perisoreus c. sanfordi is a resident in Newfoundland and Nova Scotia [3].

ECOSYSTEMS [39]:
FRES10 White-red-jack pine
FRES11 Spruce-fir
FRES19 Aspen-birch
FRES20 Douglas-fir
FRES21 Ponderosa pine
FRES22 Western white pine
FRES23 Fir-spruce
FRES24 Hemlock-Sitka spruce
FRES25 Larch
FRES26 Lodgepole pine
FRES27 Redwood
FRES35 Pinyon-juniper

STATES/PROVINCES: (key to state/province abbreviations)
UNITED STATES

AL AK AZ CA CO ID ME MI MN MT
NE NH NM NY ND OR SD UT VT WA
WI WY

CANADA
AB BC MB NB NF NT NS NU ON PE
PQ SK YK


BLM PHYSIOGRAPHIC REGIONS [17]:
1 Northern Pacific Border
2 Cascade Mountains
4 Sierra Mountains
5 Columbia Plateau
6 Upper Basin and Range
7 Lower Basin and Range
8 Northern Rocky Mountains
9 Middle Rocky Mountains
10 Wyoming Basin
11 Southern Rocky Mountains
12 Colorado Plateau
15 Black Hills Uplift

KUCHLER [65] PLANT ASSOCIATIONS:
K001 Spruce-cedar-hemlock forest
K002 Cedar-hemlock-Douglas-fir forest
K003 Silver fir-Douglas-fir forest
K004 Fir-hemlock forest
K005 Mixed conifer forest
K006 Redwood forest
K008 Lodgepole pine-subalpine forest
K011 Western ponderosa forest
K012 Douglas-fir forest
K013 Cedar-hemlock-pine forest
K014 Grand fir-Douglas-fir forest
K015 Western spruce-fir forest
K016 Eastern ponderosa forest
K017 Black Hills pine forest
K018 Pine-Douglas-fir forest
K020 Spruce-fir-Douglas-fir forest
K021 Southwestern spruce-fir forest
K023 Juniper-pinyon woodland
K093 Great Lakes spruce-fir forest
K094 Conifer bog
K095 Great Lakes pine forest
K096 Northeastern spruce-fir forest
K106 Northern hardwoods
K107 Northern hardwoods-fir forest
K108 Northern hardwoods-spruce forest

SAF COVER TYPES [32]:
1 Jack pine
5 Balsam fir
12 Black spruce
13 Black spruce-tamarack
15 Red pine
16 Aspen
18 Paper birch
21 Eastern white pine
22 White pine-hemlock
24 Hemlock-yellow birch
33 Red spruce-balsam fir
38 Tamarack
107 White spruce
201 White spruce
202 White spruce-paper birch
203 Balsam poplar
204 Black spruce
205 Mountain hemlock
206 Engelmann spruce-subalpine fir
208 Whitebark pine
210 Interior Douglas-fir
212 Western larch
217 Aspen
218 Lodgepole pine
219 Limber pine
224 Western hemlock
225 Western hemlock-Sitka spruce
227 Western redcedar-western hemlock
228 Western redcedar
229 Pacific Douglas-fir
230 Douglas-fir-western hemlock
232 Redwood
237 Interior ponderosa pine
239 Pinyon-juniper
243 Sierra Nevada mixed conifer
244 Pacific ponderosa pine-Douglas-fir
245 Pacific ponderosa pine
251 White spruce-aspen
252 Paper birch
253 Black spruce-white spruce
254 Black spruce-paper birch
256 California mixed subalpine

SRM (RANGELAND) COVER TYPES [103]:
109 Ponderosa pine shrubland
110 Ponderosa pine-grassland
411 Aspen woodland
412 Juniper-pinyon woodland
920 White spruce-paper birch
921 Willow

BIOLOGICAL DATA AND HABITAT REQUIREMENTS

SPECIES: Perisoreus canadensis
  Chris Evans, University of Georgia, www.forestryimages.org

TIMING OF MAJOR LIFE HISTORY EVENTS:
Mating: Gray jays typically breed at 2 years of age. Pairs are monogamous and remain together for their lifetime, but a male or female will find another mate following the disappearance or death of their partner [113]. Gray jay pairs breed during March and April, depending on latitude [97,112,113], in permanent, all-purpose territories [53,76,97,112,113]. Second broods are not attempted, perhaps allowing greater time for food storage (see Caching) [97,113].

Gray jays cooperatively breed [112,114,129]. Strickland [112] studied cooperative breeding of gray jays in Algonquin Provincial Park, Ontario, and La Verendrye Provincial Park, Quebec. In early June, when broods were 55 to 65 days old, the young fought amongst themselves until dominant juveniles forced their siblings to leave the natal area. Dominant juveniles, known as "stayers", remained with their parents, and "leavers" left the natal territory to join an unrelated pair who failed to breed. Two-thirds of "stayers" were male [112].

During the nest-building phase of the subsequent breeding season, approximately 65% of gray jay trios included "stayers" from the previous spring and their parents, and approximately 30% of trios included an unrelated "leaver". Occasionally, 2 nonbreeders accompany a pair of adults. "Stayers" may eventually inherit the natal territory and breed, and "leavers" may eventually fill a vacancy nearby or form a new breeding pair on previously unoccupied ground [112]. The role of "stayers" is to retrieve caches and bring food to younger siblings [114,129]; however, this is only allowed by the parents during the postfledgling period [112,114,129]. Until then, parents are hostile toward the "stayer". This may reduce the frequency of predator-attracting visits to the nest when young are most vulnerable. The benefits of allofeeding may include "lightening the load" for the breeding pair, which may possibly increase longevity, reducing the probability of starvation of nestlings, and detecting and mobbing predators near the nest [114].

Nesting: Nesting typically occurs in March and April [97,113]. Male gray jays choose a nest site in a mature coniferous tree [53,76] and take the lead in construction [113]. Gray jay nests were found in black spruce (Picea mariana), white spruce (Picea glauca), and balsam fir (Abies balsamea) trees in Ontario and Quebec, with black spruce predominating [97,113]. Cup-shaped nests [53,64,76,98] were constructed with brittle dead twigs pulled off of trees, as well as bark strips and lichens. Cocoons of the forest tent caterpillar (Malacosoma dysstria) filled the interstitial spaces of the nest [113]. Nests are usually built on the southwestern side of a tree for solar warming and are usually <1 nest diameter from the trunk [97]. Nest height is typically 8 to 30 feet (2.4-9.1 m) above the ground [72,97]. The average height of 264 nests surveyed in Algonquin Provincial Park was 16 feet ± 9.2 (4.9 m ± 2.8) above ground [97].

Clutch size is 2 to 5 eggs. The mean clutch sizes of gray jays in Algonquin Provincial Park and La Verendrye Provincial Park were 3.03 and 3.18 eggs, respectively. Incubation is performed only by the female [97,113] and lasts an average of 18.5 days [113].

Fledging: Gray jay young are altricial.

Nestling growth is most rapid from the 4th through the 10th day following hatching. Young are fed food carried in the throats of both parents [97,113]. They are fed by the accompanying nonbreeding 3rd bird ("stayer") only during the postfledgling period (see Mating) [114,129]. Food is a dark brown, viscous paste containing primarily arthropods [97,113]. Young gray jays leave the nest between 22 and 24 days after hatching [113]. Juveniles reach full adult measurements within 5 months [43].

Natal dispersal distance for the gray jay is a median of 0.0 mile (0.0 km) for males, 1.7 miles (2.8 km) for females, and a maximum distance of 7.0 miles (11.3 km) for males and females [112].

Survival: In studies conducted in Ontario and Quebec, the mortality rate for nonbreeding dominant juveniles ("stayers") was 52%, and mortality was 85% for nonbreeding "leavers" between fledging in June to approximately mid-October. From fall to the following breeding season in March, further nonbreeder mortality was 50%. Territory-holding adult gray jays experienced low mortality rates (15.1% and 18.2% for males and females, respectively) [112]. The oldest known female gray jay was 16 years old, and one male was at least 14 years old [113]. Food-storing birds such as the gray jay may live longer than other species due to the increased probability of food availability [92].

PREFERRED HABITAT:
Gray jays are habitat generalists [62,73,75,96,99,102,120,121,124,132] but prefer mature coniferous habitats [56,87,97,106,113,120] and mixed conifer-deciduous forests with spruce (Picea spp.) typically present [113].

Pure hardwood stands are used for foraging but are not part of the defended territory [97].

Theberge [120] examined the density of gray jays in various vegetation communities in Kluane National Park, Yukon. Gray jays were most abundant in the mature white spruce community but were present in 7 distinctly different vegetation communities, indicating a lack of habitat specialization [120]:

Vegetation community Upland willow (Salix spp.) shrub Lowland willow shrub White spruce-balsam poplar (Populus balsamifera ssp. balsamifera) Mature white spruce Riparian balsam poplar Balsam poplar parkland Subalpine
Density of males per 40 ha 10.0 6.7 6.0 16.8 10.0 12.5 1.7
COVER REQUIREMENTS:
Conifers, particularly spruce (Picea spp.), are the preferred cover for the gray jay. The territory size for a pair of gray jays in Algonquin Provincial Park and La Verendrye Provincial Park was 0.25 square mile [97].

Stand age: Although gray jays prefer mature coniferous forests [56,73,87,97,106,113,120], they can be found occupying all forest age classes [121,124].

Mature forest: During winter months, gray jays preferred late-seral (325 to >500 years old) Douglas-fir (Pseudotsuga menziesii) stands in the southern Gifford Pinchot National Forest, Washington [56].

Gray jays surveyed in young (40-70 years old), mature (100-196 years), and old-growth (204-450 years) Douglas-fir/hardwood stands in northwestern California and southwestern Oregon reached peak abundance in the old-growth stands [87].

Gray jays were most abundant in mature stands and least abundant in young stands of a quaking aspen (Populus tremuloides) mixed-wood forest in Alberta. The 3 age classes studied were: young (20-30 years old); mature (50-65 years old); and old stands (120+ years old) [99].

Of 5 seral stages studied in a forest dominated by Douglas-fir, western hemlock (Tsuga heterophylla), and red alder (Alnus rubra) in the Oregon Coast Ranges, gray jays were significantly (P<0.05) positively associated with late-seral forest structure and were most abundant in large saw timber plots (>20% cover, >21 inch (>53.2 cm) mean DBH) [73].

All age classes: Habitat generalists including the gray jay were common in all 3 age classes (40-59 years, 60-79 years, and 80+ years) of mature balsam fir forest in Newfoundland [121].

In ponderosa pine (Pinus ponderosa) habitat in the Black Hills, South Dakota, gray jays utilized the sapling-pole, mature, and old-growth stages, but their habitat preference changed between the summer breeding season and winter [75,96]. During summer, optimal habitat included mature and old-growth ponderosa pine [75]. During winter, gray jays preferred mature and sapling-pole ponderosa pine stands [96].

As habitat generalists, gray jays may not be susceptible to changes in forest age distribution in jack pine (Pinus banksiana) forests near the White River in north-central Ontario. Jack pine stands were even-aged and ranged from 3 to 100 years old. Gray jays were most abundant on 18- to 20- year-old stands, but were not confined to that age class [124].

During the winter gray jay populations were greatest in the youngest stands (14 years old) compared to 30-year-old and 60-year-old stands in a mixed-age quaking aspen forest at Medicine Lake, Alberta [132].

Stand composition/structure: Most of the research on gray jays has compared various silvicultural strategies or analyzed succession after harvesting. Gray jays exhibit a range of responses to habitat fragmentation. They can be positively [51,62] or negatively affected [36,37] and, in most cases, show mixed or no response [10,25,44,46,84].

Positively affected by fragmentation: The mean number of bird species was measured in old-growth, fragmented old-growth and selectively harvested western redcedar (Thuja plicata)-western hemlock forests on the Priest Lake Ranger District of the Idaho Panhandle National Forest. Gray jay populations were greatest in the fragmented old-growth forest, characterized as an older-aged forest with 1- to 8-year-old clearcuts embedded [51]:

Mean number (x ) of gray jays along 24 counting points in each area
Old growth Fragmented old growth Selectively harvested P
0.06 (0.03) 0.14 (0.09) 0.03 (0.02) 0.04

The mean abundance of gray jay was greater on clearcut stands than unfragmented stands in a forest dominated by Engelmann spruce (Picea engelmannii) and subalpine fir (Abies lasiocarpa) in the Medicine Bow National Forest, Wyoming, but the differences were not statistically significant [62].

Negatively affected by fragmentation: Birds such as the gray jay, which forage in the foliage of trees, may decline following logging due to the reduction of total biomass foliage rather than decreased foliage height diversity or loss of tree volume. A decline in insect prey may also occur following logging [36,37].

Mixed responses to habitat fragmentation: During the winter in Oregon, gray jay abundance did not differ between commercially thinned and unthinned Douglas-fir stands in the Tillamook State Forest and the central Coast Ranges. Four thinned and four unthinned stands that were 40 to 55 years old and 161 to 1,260 acres (65-510 ha) in size were chosen in each of 2 locations. During the summer gray jays were more abundant (P<0.01) in unthinned versus thinned stands in the Tillamook State Forest; however, they were more abundant (P=0.10) in thinned versus unthinned stands in the central Oregon Coast Ranges. The abundance of gray jays varied positively with red alder cover and negatively with pole layer height.

Bird populations were compared in 6 lodgepole pine (Pinus contorta) communities in the Uinta Mountains of Utah. The 6 communities were mature forest; stagnated forest composed of dense lodgepole pine stands; a 1940 clearcut that left no residual trees; a stagnated stand that was bulldozed and then broadcast burned; wet meadows along streams; and dry meadows with a dense mixture of grasses and forbs under widely scattered lodgepole pine. Gray jays were present in most of the communities and appeared to be uninfluenced by logging [10]:

Density of gray jays (individuals/100 acres (40 ha))
Mature forest Stagnated forest 1940 clearcut forest Bulldozed & burned forest Wet meadow Dry meadow
6 <1 <1 4 ---- 7

Breeding bird responses to 3 silvicultural alternatives were examined in a Douglas-fir forest on the McDonald-Dunn Forest, Oregon. The 3 treatments were: (1) small-patch group selection, in which ⅓rd of the wood volume was removed, representing low-severity disturbance; (2) 2-story treatment, in which ¾ths of the wood volume was removed, representing a moderate to high-severity disturbance; (3) modified clearcut treatment, in which 1.2 green trees/ha were retained, representing a high-severity disturbance; and (4) unharvested control for each treatment. One replicate was harvested each year for 3 years. The mean abundance of gray jays was highest in small-patch group selection cuts for each of the 3 years [25]:

Mean abundance of gray jays (no. of observations/5 ha (x))
  Year 1 Year 2 Year 3
Control 0.3 (0.3) 1.3 (1.3) 1.0 (0.6)
Small-patch 1.8 (0.5) 1.6 (0.6) 1.1 (0.4)
2-story 1.7 (1.2) 0.5 (0.3) 0.2 (0.2)
Modified clearcut 1.5 (0.6) 0.0 (0.0) 0.2 (0.2)

Harrison and others [46] studied the effects of partial cutting on songbirds in mixed-wood forests near Peace River in northwestern Alberta. Dominant trees included quaking aspen, balsam poplar, and lodgepole pine. The mean abundance change for gray jay was not statistically significant.

Six seral stages within a sub-boreal spruce forest dominated by quaking aspen in valley bottoms and lowlands were surveyed to examine diversity of bird communities near Smithers, British Columbia. The seral stages were clearcut; shrub/herb; pole/sapling (<15 years); young quaking aspen (15- 49 years); mature quaking aspen (50+ years); and mature quaking aspen mixed with Engelmann spruce and lodgepole pine. Gray jays were present in the mixed quaking aspen stage and seen foraging in clearcuts, but were probably not nesting in the clearcut due to lack of suitable habitat [84].

FOOD HABITS:
Gray jays are omnivorous [76,97,98,113]. Foods eaten include arthropods [113], small mammals [68], nestling birds [21,22,116,123] (see Predation), carrion [97,113], fungi [113], fruits such as chokecherry (Prunus virginiana) [97], and seeds [97]. Two gray jays were seen eating slime mold (Fuligo septica) near Kennedy Hot Springs in the Glacier Peak Wilderness, Washington. This was the 1st report of any bird consuming slime mold in the field [117].

Occasionally, gray jays eat live prey. Lescher and Lescher [68] witnessed a gray jay kill an unidentified, live small rodent in Wisconsin. Barnard [12] was the 1st to witness an in-flight gray jay capture of a magnolia warbler (Dendroica magnolia) for consumption.

Gray jays have been seen landing on moose (Alces alces) to remove and eat engorged winter deer ticks (Dermacentor albipictus) during April and May in Algonquin Provincial Park. Researchers also found a gray jay nest containing a brooding female, 3 hatchlings, and 3 warm, engorged winter deer ticks. Because the winter deer ticks were too large for the hatchlings to eat, it was hypothesized that the ticks may have served as "hot water bottles", keeping hatchlings warm when parents were away from the nest [1].

Gray jays are suspected but not proven to prey on nests of the threatened marbled murrelet (Brachyramphus marmoratus) in coastal areas of the Pacific Northwest [88].

Foraging behavior: Gray jays do not hammer food with their bill as do other jays, but wrench, twist, and tug food apart. Gray jays commonly carry large food items to nearby trees to eat or process for storage, possibly as defense against large scavengers [113]. They are "scatterhoarders", caching food items among scattered sites for later consumption [69,71,128].

Any food intended for storage is manipulated in the mouth and formed into a bolus (rounded mass) that is coated with sticky saliva, adhering to anything it touches. The bolus is stored in bark crevices, under tufts of lichen, or among conifer needles [97].

Risk and energy expenditure are factors in food selection for gray jays. Gray jays select food on the basis of profitability to maximize caloric intake. Increased handling, searching, or recognition times for a preferred food item lowers its profitability [71].

The gray jay takes advantage of man-made sources of food, hence the names "camp robber" and "whiskey Jack". According to Maccarone and Montevecchi [71], human observers do not inhibit gray jay's feeding behavior; however, Rutter [97] claims that "once having identified man with food it does not forget". He found that after a nesting female was accustomed to being fed by humans she could be enticed to leave the nest during incubation and brooding [97].

Predation: Gray jays commonly prey on nestling birds [22,29,88,123]. Nests are located visually by moving from perch to perch and scanning surroundings [113]. Gray jay predation on nestling birds is temporally homogenous throughout the passerine breeding season [105]. Avian nest predation by gray jays is not necessarily higher in fragmented versus unfragmented forest [21,29,116,123].

Boulet and others [21] examined bird nest predation in a commercially fragmented boreal black spruce forest intermixed with jack pine, balsam fir, quaking aspen, and paper birch near Lake Saint-Jean, Quebec. Gray jays directed their attacks on artificial arboreal nests more often than artificial ground nests. Depredation of nests was positively related to the presence of the lake and jack pine. Gray jays may have preferred preying on avian nests in jack pine versus black spruce habitat because jack pine forests were more open, and trees did not conceal nests as well. Gray jays may have favored foraging along lakeshores and moist patches due to the high density of insects. No relationship was found between the fragmented forest and predation [21].

The potential for egg predation by gray jays was greater in riparian forest strips than in clearcuts in a second-growth boreal balsam fir forest in Montmorency Forest, Quebec [29].

Stuart-Smith and Hayes [116] examined the influence of residual tree density on predation of artificial and natural songbird nests. The study took place in the White River and Lussier River Watershed, southeastern British Columbia, in a forest dominated by Douglas-fir, white spruce, and western larch. Twenty-four plots of similar age were chosen (16 logged, 8 burned by wildfire); they varied in residual tree density between 0 and 180 trees/ha. Residual trees apparently did not increase predation on nesting songbirds by the gray jay. However, a moderate increase in nest predation occurred in logged plots adjacent to or surrounded by mature conifer forest, which is the preferred habitat for gray jays [56,87,97,106,113,120]. Retaining residual trees would outweigh the possible increased risk of nest predation, except in areas where nesting birds are at very low numbers and potential risk by gray jays is high [116].

When predation rates on bird nests by the gray jay were compared in clearcut, green-tree retention stands, and mature western hemlock stands in the west-central Oregon Cascade Ranges, predation rates were highest in green-tree retention stands. This may have been due to increased availability of perch sites for avian predators such as the gray jay [123].

Caching: Gray jays cache thousands of food items every day during the summer for use the following winter [112,126,127,129]. Caching behavior is thought to have evolved for several reasons. It allows for permanent residence in boreal and subalpine forests [113], ensures a food source in areas with high elevations and cyclic availability of food resources, and favors the retention of young and a kin-selected social organization [92]. In southern portions of the gray jay's range, food is not cached during summer because of the chance of spoilage and the reduced need for winter stores [113]. Cached items can be anything from carrion to bread crumbs and are formed into a bolus before being cached [97]. Cached food is sometimes used to feed nestlings and fledglings [97].

Caching is inhibited by the presence of Steller's jays [23] and gray jays from adjacent territories [126,127], which follow resident gray jays to steal cached food [23]. Gray jays carry large food items to distant cache sites for storage more often than small food items. To prevent theft, they also tend to carry valuable food items further from the source when caching in the company of 1 or more gray jays [127]. Scatterhoarding discourages pilferage by competitors. Cache thievery increases with increased cache density [126].

When exploiting distant food sources found in clearings, gray jays temporarily concentrated their caches in an arboreal site along the edge of a black spruce forest in interior Alaska. This allowed a high rate of caching in the short term and reduced the jay's risk of predation. A subsequent recaching stage occurred, and food items were transferred to widely scattered sites to reduce theft [128].

PREDATORS:
Gray jays warn each other of predators by whistling alarm notes, screaming, chattering, or imitating, and/or mobbing predators [113].

Gray jays are consumed by several bird species including great gray owls (Strix nebulosa) [78], northern hawk-owls (Surnia ulula) [93], and Mexican spotted owls (Strix occidentalis lucida) [122,131].

Gray jay remains were found in the nest sites of fisher (Martes pennanti) [85] and American marten (Martes americana) [52]. Red squirrel (Tamiasciurus hudsonicus) eat gray jay eggs [97].

MANAGEMENT CONSIDERATIONS:
Gray jay populations are decreasing slightly. Breeding Bird Surveys conducted from 1966 to 1992 revealed that gray jay populations declined at a rate of 1.28%/year [82]. Gray jay abundance decreased in ponderosa pine forests in New Mexico from 1911 to 1961 [101].

The Nicolet National Forest Bird Survey in northeastern Wisconsin showed gray jay populations decreased from 1989 to 2002; however, the Breeding Bird Survey conducted in the same forest found gray jay populations increased during this time. This may be because Breeding Bird Survey routes were established randomly along roadsides [91], whereas the Nicolet National Forest Bird Survey routes were established within gray jay habitat [54].

Members of a guild are more likely to respond similarly when they are grouped according to their association with habitat zones instead of by the "guild approach", which groups bird species into guilds based on their foraging and nesting behavior. According to Skinner [108], the "guild approach" may be problematic for 2 reasons: a lack of consistency in how investigators assign bird species to guilds and a false assumption that the response of 1 species in a guild is representative of all species in that guild [108].

Silviculture: Because gray jays prefer mature forests [56,75,87,97,102,106,113,120], management activities such as harvesting mature and old-growth ponderosa pine stands [75], clearcutting, conversion of hardwood or mixed stands to pure conifer stands, and a maximum rotation period of 100 years may reduce the quantity or quality of preferred habitat for the gray jay [106]. Nevertheless, maintaining as much landscape diversity as possible is beneficial to the gray jay [102]. For more information on silvicultural treatments and the gray jay, (see Stand composition/structure).

The amount and orientation of residual live and dead trees is an important component of stand structure following disturbance [53]. Wakkinen and Reese [130] and Hobson and Schieck [53] suggest managing for both dead and partially dead snags of different sizes in a variety of stand types to provide nesting, feeding, and perching sites for birds.

Dwarf mistletoe: Gray jays are one of the most common vectors in the long-distance dispersal of dwarf mistletoe (Arceuthobium spp.) seeds [16,47,79]. Seeds are inadvertently picked up on gray jay feathers when birds forage or nest in infected trees [55,79,86]. Bennetts and others [16] suggest control of dwarf mistletoe "may not be justified, practical, or even desirable" in areas where management goals are not focused on timber production. Pineland dwarf mistletoe (A. vaginatum) in central Colorado may have positive effects on avian habitat, creating a mosaic of habitat patches for nesting and cover [16].

Some timber management practices may reduce the quantity or quality of preferred habitat for the gray jay. A 150- year-old, even-aged western hemlock forest on the Siuslaw National Forest, Oregon, was inventoried for wildlife management needs. The gray jay, which may require western hemlock forests older than 100 years, may be adversely affected by timber management activities that include clearcutting, conversion of hardwood or mixed stands to pure conifer stands, and rotation periods of less than 100 years [106].

Other: The impact of repeated human intrusions on gray jays was studied in a subalpine forest in the Snowy Mountains of Wyoming. The average number of gray jays was higher on intruded sites than on control sites, as was the probability of intrusion reoccurring. The potential for gray jay predation may be higher in human-intruded areas, but more studies are needed [42].

The gray jay has a high potential for damage from exposure to aerial insecticide treatments due to open-cup nests [89].

FIRE EFFECTS AND USE

SPECIES: Perisoreus canadensis
DIRECT FIRE EFFECTS ON ANIMALS:
As of 2006, no research directly investigated gray jay mortality due to fire. Fire can kill gray jays [80], but mortality is generally minor for adult birds [95]. If fires occur during the breeding season, mortality of nestlings or fledglings is possible, so adult birds may experience reduced reproduction rates [80].

HABITAT-RELATED FIRE EFFECTS:
Modifications in the food supply and habitat of gray jays may occur following fire, as well as changes in the abundance of competitors and predators [95]. According to Finch and others [33], the effects of fire on birds and their habitat vary with: 1) the severity and extent of the fire; 2) temporal scales; 3) life history characteristics of the bird species; and 4) whether or not salvage logging occurs following fire. Severe fires alter the forest structure more than low-severity fires, and a stand-replacing fire may result in the successional replacement of a bird species with a different bird species. Large, severe fires may greatly alter bird habitat in the short term but may be necessary for long-term maintenance of some forest types [58]. Fire may be beneficial to cavity-nesting, timber-drilling, grain-collecting, and fly-catching birds due to increased nesting habitat and food supplies [18,19,24,45,50,58,111,119]. Salvage logging may reduce the benefits of fire to birds that utilize snags for cavity nesting and foraging [58].

A meta-analysis of studies of bird responses to fire showed that gray jays and other bird species that share the same nest type, nest layer, and foraging guild do not show a distinct positive or negative response to fire. The analysis is shown below; the table does not distinguish between fire types (wildland, prescribed, stand-replacing, understory, various severities), vegetation types, or time since fire [98]:

Response to fire (% of studies)
  n positive negative none mixed
Nest type: Open-cup nest 544 29 23 39 9
Nest layer: Canopy nest 423 31 18 42 9
Foraging guild: Omnivore 296 32 21 37 9

Gray jays are usually present in postfire habitats after fires of varying severities but experience lower abundance in burned than unburned areas. Results of studies examining gray jay responses to wildfire, prescribed burning, logging versus burning, and salvage logging follow.

Wildfire: Changes in bird abundance and species composition following mixed-severity wildfires were studied in low-elevation ponderosa pine/Douglas-fir habitat and mid-elevation mixed-conifer and lodgepole pine habitats in the Bitterroot National Forest in west-central Montana. In July and August 2000, dry lightning storms ignited fires of 99 to 135,900 acres (40-55,000 ha) in size; the fires ranged from low-severity to severe. Transects had been established in 1994 and 1995 before the wildfires occurred, and 1 year following the fires, burned and unburned transects of differing fire severities were compared. The mean relative abundance (number of gray jays detected within 100 m/point × 100 ± standard error) for gray jays was lowest following fire [109,110]:

Mean relative abundance ± x

 

Before fire

After fire

Unburned points (n=120) 9.8 ± 2.2 8.1 ± 2.1
Burned points (n=122) 12.4 ± 2.7 4.2 ± 1.5

Gray jays were ubiquitous in various successional portions of lodgepole pine and Engelmann spruce-subalpine fir forests following wildfires in Grand Teton and Yellowstone National Parks, Wyoming; however, they were most abundant in severely burned areas 43 and 44 years following fire, which is typically when the canopy closes following severe wildfire. Ten areas were sampled in both Parks ranging from 1 to 304 years after fire and 40 to several hundred acres in size. In Grand Teton National Park, unburned, moderately burned, and severely burned areas were examined. In moderately burned areas, 40% or more of the tree understory was alive 1 year following the fire, and part of the grass-forb-shrub understory was unburned. In severely burned areas, all aboveground vegetation was killed by a severe crown fire. In Yellowstone National Park, all sampling areas were severely burned in 1667 and 1956 [119].

Gray jay densities were highest in unburned versus burned lodgepole pine and Engelmann spruce-subalpine fir forests in Yellowstone National Park, Wyoming. In 1974, the Trail Creek Wildfire burned 581 acres (235 ha) of 250-year-old lodgepole pine forest with an understory of Engelmann spruce and subalpine fir. In 1976, the Divide Wildfire burned 1,601 acres (648 ha) of 350+ year-old Engelmann spruce-subalpine fir forest. Fire severities were not documented. Avian communities were surveyed in 1978 and 1979 [83].

Gray jays preferred the ecotone and unburned areas of subalpine lodgepole pine forest 8 years following a high-severity wildfire on the Roosevelt National Forest, Colorado. The fire burned approximately 470 acres (190 ha), killing or top-killing virtually all aboveground vegetation. The total number of gray jays recorded on 6-point counts on three 49 acre (20 ha) plots is shown below [94]:

Total number of gray jays (and no. of territories)/ plot

Burned Ecotone Unburned
0 10 (2) 5 (1)

A literature review reported that gray jays were more abundant on unburned sites than on 23 severely burned conifer forests in the western United States [63].

Canopy cover did not predict distribution of canopy foragers such as the gray jay between burned and unburned lodgepole pine forests in Grand Teton National Park. Two-year postfire and six-year postfire sites were compared with unburned sites. Details about the size and severity of the fires were not given. Gray jays utilized the 2-year burns, 6-year burns, and unburned sites most during the postbreeding season. The mean frequency of observations during the breeding and postbreeding season of the gray jay is shown below [108]:

Mean frequency of observations × 100 (frequency of observations)

Treatment

Postfire year 2

Postfire year 6 unburned
Breeding season 4 (3) 5 (3) 2 (1)
Postbreeding season 36 (17) 13 (5) 28 (8)

Prescribed burning: Bock and Bock [20] studied the effects of prescribed fire on birds in ponderosa pine forests in the southern Black Hills, South Dakota. One area was burned in October 1979, covering 156 acres (63 ha). Another study area was burned in April and May 1980, burning 806 acres (326 ha). Both burns were low-severity in local isolated spots. Point counts were conducted in June 1980 and June 1981 on burned and unburned plots. Gray jay abundance was greatest on unburned plots for both years [20]:

Mean no. of breeding birds
Year Burned Unburned
1980 0 0.7
1981 0.1 0.7

Logging versus wildfire: Clearcutting and stand-replacing fire both lead to early-successional forest; however, they do not provide the same habitat conditions [53]. Clearcuts and wildfires are distinct from each other for several reasons: 1) logging causes greater site disturbance due to road construction and logging equipment; 2) logging removes stems from a site; 3) wildfire leaves live residual stands, burned trees, and downed woody debris; 4) wildfire size, frequency, and distribution are different from cutblocks; and 5) wildfire is not predictable and does not target the most valuable trees [58]. Nevertheless, research comparing gray jays on logged and burned sites does not show any clear pattern of preferences.

Bird communities were compared between burned and harvested sites in a quaking aspen-dominated boreal mixed-wood forest in north-central Alberta. Three replicate stands were chosen from each class (1,14, and 28 postdisturbance years) and treatment (wildfire vs. harvest). More than 95% of the canopy trees were dead on burned sites. An average of 6% of preharvest trees remained on the harvested sites. Gray jay density was greater within 14-year-old postfire stands than in postharvest stands. Gray jays may have been responding to differences in the herb and shrub strata between postfire and postharvest stands [53]:

Density of gray jays (mean number of individuals (± x)/25acres)
Postdisturbance year 1 14 28
Postfire 0.7 ± 0.7 4.3 ± 2.0 1.3 ± 0.3
Postharvest 1.7 ± 0.9 0.0 ± 0.0 0.0 ± 0.0

Avian response to forest management practices was examined in mature ponderosa pine forests mixed with Douglas-fir or grand fir (Abies grandis) in Montana. Three site categories were chosen: 1) control sites containing either ladder fuels or encroachment by small- or medium- diameter trees; 2) treated sites that had been logged, underburned, or a combination of the 2 to reduce fuels and create open structural conditions; and 3) sites with a natural underburn in 2000. Gray jays were present in all 3 sites but most abundant in the control [133].

In northwestern Lac Saint Jean, Quebec, gray jays showed no significant (P>0.05) difference in abundance in postfire and postlogging stages in stands formerly dominated by black spruce [59].

Avian abundance was compared in wildfire and clearcut areas in a former black spruce forest near Goose Bay, Newfoundland after 5,14, and 27 years of succession. Details about the size and severity of the burn were not documented. Gray jay was not a common species in the study area but may have slightly preferred clearcut plots over burned plots [107].

Schulte and Niemi [100] surveyed bird communities in early-successional forests following logging and fire near Tower, Minnesota. Logged sites had been clearcut and contained residual trees and residual patches of trees. Wildfire sites were dominated by quaking aspen, and 5,189 acres (2,100 ha) of forest had burned. Logged sites were chosen to match the time of disturbance, predisturbance type, and soils of the burned sites. According to the vegetation analysis, habitat heterogeneity was greater in burned areas. The gray jay was 1 of 5 bird species highly associated with snags in this study; snags were probably utilized for foraging. Gray jay abundance did not differ significantly between logged and burned sites [100]:

Gray jay abundance (territorial males/ha)

Mean

x P value
Logged 0.02 0.02 0.12
Burned 0.10 0.06

Salvage logging: Resident species such as the gray jay were less likely to be detected in salvaged areas of a burned mixed-wood forest (dominant trees were white spruce and quaking aspen), a jack pine forest, and a quaking aspen forest near Meadow Lake, Saskatchewan than in logged areas. In 1995, a wildfire burned 98,840 acres (40,000 ha), killing a majority of the trees in the burned areas. Salvage logging took place in 1997. In 1998, surveys were conducted in unburned, burned, and salvaged forests. The indicator value of gray jay for each treatment in the 3 habitat types is shown below [76]:

Habitat type Indicator value (% )
Unburned Burned Salvaged P
Mixed-wood 36 41 24 0.999
Jack pine 34 22 1 0.106
Quaking aspen 0 17 not salvaged 0.468

The following table provides fire return intervals for plant communities and ecosystems where the gray jay is important. For further information, see the FEIS review of the dominant species listed below.

Community or Ecosystem Dominant Species Fire Return Interval Range (years)
silver fir-Douglas-fir Abies amabilis-Pseudotsuga menziesii var. menziesii >200
grand fir Abies grandis 35-200 [6]
tamarack Larix laricina 35-200 [81]
western larch Larix occidentalis 25-350 [7,14,30]
Great Lakes spruce-fir Picea-Abies spp. 35 to >200
northeastern spruce-fir Picea-Abies spp. 35-200 [31]
Engelmann spruce-subalpine fir Picea engelmannii-Abies lasiocarpa 35 to >200 [6]
black spruce Picea mariana 35-200
conifer bog* Picea mariana-Larix laricina 35-200 [31]
pinyon-juniper Pinus-Juniperus spp. <35 [81]
whitebark pine* Pinus albicaulis 50-200 [2,5]
jack pine Pinus banksiana <35 to 200 [28,31]
Rocky Mountain lodgepole pine* Pinus contorta var. latifolia 25-340 [13,14,118]
Colorado pinyon Pinus edulis 10-400+ [35,40,61,81]
Sierra lodgepole pine* Pinus contorta var. murrayana 35-200
Pacific ponderosa pine* Pinus ponderosa var. ponderosa 1-47 [6]
interior ponderosa pine* Pinus ponderosa var. scopulorum 2-30 [6,11,66]
red pine (Great Lakes region) Pinus resinosa 3-18 (x=3-10) [27,38]
red-white pine* (Great Lakes region) Pinus resinosa-P. strobus 3-200 [28,48,70]
eastern white pine Pinus strobus 35-200
eastern white pine-eastern hemlock Pinus strobus-Tsuga canadensis 35-200 [125]
aspen-birch Populus tremuloides-Betula papyrifera 35-200 [31,125]
quaking aspen (west of the Great Plains) Populus tremuloides 7-120 [6,41,74]
Rocky Mountain Douglas-fir* Pseudotsuga menziesii var. glauca 25-100 [6,8,9]
coastal Douglas-fir* Pseudotsuga menziesii var. menziesii 40-240 [6,77,90]
redwood Sequoia sempervirens 5-200 [6,34,115]
western redcedar-western hemlock Thuja plicata-Tsuga heterophylla >200
western hemlock-Sitka spruce Tsuga heterophylla-Picea sitchensis >200 [6]
*fire return interval varies widely; trends in variation are noted in the species review

FIRE USE:
The data currently available suggest that gray jays are present in burned forests but are usually more abundant in unburned habitats [20,63,83,94,109,110,133]. This may be due to their preference for mature trees for foraging and nesting [53,56,76,87,97,106,113,120]. Because gray jays are habitat generalists [62,73,75,96,99,102,120,121,124,132] and omnivores [76,97,98,113], they may exhibit greater flexibility in response to habitat disturbances such as fire and logging than other bird species. Most studies examining gray jay response to fire have been conducted several years following wildfire. More research needs to be conducted on the immediate effects of low- and high-severity wildfire on gray jay, as well as the best time of year to conduct prescribed burning for gray jay management.

The amount and orientation of residual live and dead trees is an important component of stand structure following disturbance [53]. Gray jays utilize snags for perch sites [53,113,116,123,130], so they may be negatively affected by salvage logging. Wakkinen and Reese [130] and Hobson and Schieck [53] suggest managing for both dead and partially dead snags of different sizes in a variety of stand types to provide nesting, feeding, and perching sites for birds such as the gray jay.

Smucker and others [110] suggest that managers prescribe and allow for a range of fire severities to meet the needs of all bird species.

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