SPECIES

Northern Cardinal Cardinalis cardinalis Scientific name definitions

Sylvia L. Halkin, Daniel P. Shustack, M. Susan DeVries, Jodie M. Jawor, and Susan U. Linville
Version: 2.0 — Published February 12, 2021

Diet and Foraging

Feeding

Main Foods Taken

Average annual consumption 29% animal, 71% vegetable matter; feeds nestlings almost exclusively animal matter (217, 100).

Microhabitat for Foraging

Opportunistic feeder. In early spring, forages on ground in open areas where wild seeds are available, including fields, meadows, and forest leaf litter. When canopy leaves emerge, eats buds and insect larvae on trees and shrubs (190). In fall, takes fruits and seeds from plants and ground (217). Prefers broadleaf foliage to coniferous, likely due to food availability (190). May visit feeding stations throughout day, but especially common near dawn and dusk.

Food Capture and Consumption

Bill highly adapted for extracting seeds by cutting or crushing shells. Takes fruits from trees, shrubs, and vines. Commonly peels wild grapes (Vitis spp.) in bill and discards skin to consume pulp and seeds (SUL); also observed eating seeds extracted from mulberries (Morus spp.) and dropping the skin/pulp (SLH). Actively moves among branches to search foliage for insects. Observed on O'ahu Island, Hawaii, catching termites (Coptotermes formosana) in flight (218). Occasional reports of consumption of vertebrates (e.g., a field mouse) that may have been found dead (217), and carrying of non-native Anolis sagrei in Texas, with presumed intent of consumption (eBird 2020).

Diet

Major Food Items

Vegetable Food

From Martin et al. (219) and additional cited references, most foods identified to genus.

Northeast. Primary vegetable foods include fruits and seeds of grape (Vitis), smartweed (Polygonum), dogwood (Cornus), sedge (Carex), mulberry (Morus), sumac (Rhus), vervain (Verbena), tulip-tree (Liriodendron tulipifera), and domestic corn (Zea mays) and oats (Avena sativa).

Southeast. Includes bristle grass (Setaria), blackberry (Rubus), grape, sedge, panic grass (Panicum), and corn.

Southern prairies. Includes grape, doveweed (Croton), bristle grass, dogwood, mulberry, knotweed (Polygonum), and hackberry (Celtis).

Southwest. In Sonora, Mexico, fruits of Bursera (including B. hindsiana, B. microphylla, and B. laxiflora) are consumed and may be important during periods of drought (197).

Generally, probably not an effective seed disperser because seeds are masticated and digested; pulp of fruit may be discarded to access seeds (e.g., pondberry [Lindera mellisafolia; 220] and mulberry [Morus; SLH]). Consumes the fruits of wild chiles (Capsicum annuum var. aviculare) in the Sonoran Desert, but it is unclear whether seeds are consumed, and if so, whether viable seeds are defecated (221). Also consumes fruits of spicebush (Lindera benzoin; 217), honeysuckle (Lonicera; 222), and Chinese tallow (Sapium sebiferum; 223), but the fate of consumed seeds (digested, defecated in a viable state, or discarded) is not known.

Animal Food

From McAtee (217). Larval and adult insects, including beetles (Coleoptera), mantises (Mantodea) , grasshoppers (Acrididae), crickets (Gryllidae), katydids (Tettigoniidae; eggs), butterflies and moths (Lepidoptera), cicadas (Cicadidae), leafhoppers (Cicadellidae) and other small homopterans (Homoptera), stinkbugs (Pentatomidae) and other true bugs (Hemiptera), ants (Formicidae), sawflies (Symphyta), dragonflies (Anisoptera), mayflies (Ephemeroptera), lacewings (Neuroptera), and flies (Diptera). Also, spiders (Araneae), centipedes (Chilopoda), snails and occasional slugs (Gastropoda), and bivalves (Bivalvia). Known to consume periodical cicada (Magicicada spp., 224).

Quantitative Analysis

Analysis by McAtee (217) of 498 stomachs throughout year from 20 states, District of Columbia, and Ontario assessed percent diet by weight. Vegetable matter: grains, 9%; wild fruit, 24%; weeds and other seeds, 36%; miscellaneous vegetables, 2%. Animal food: beetles, 10%; grasshoppers and crickets (Orthoptera), 6%; butterflies and moths, 5%; homopterans and true bugs, 4%; ants and sawflies (Hymenoptera), 1%; other insects and non-insect invertebrates, 3%. Northern Cardinal and Pyrrhuloxia have similar animal food preferences, but cardinals eat more fruit and Pyrrhuloxia eat more grass seeds. Stomach contents of 4 nestlings included 95% animal matter and 5% vegetable matter. Major animal food items were beetles, moth and butterfly larvae, grasshoppers, and cicadas.

Food Selection and Storage

In an 18-month study at bird feeders in Maryland, preferences of 22 common components of commercial birdseed mixes were examined (225). Sunflower (Helianthus) seeds were most preferred, and black oil-type seeds were most preferred among sunflower varieties; many other seed types consumed in small quantities (225). At feeders, prefer black-oil sunflower seeds across their range (226).

Worthington et al. (227) examined digestive tract (esophagus, proventriculus, and gizzard) contents of 95 individuals from November to February in east Texas; insect parts were found, but not analyzed. Frequencies of consumption of seeds from different genera varied by study site; Callicarpa, Croton, Datura, Digitaria, Galactia, and Phytolacca were generally the most common genera eaten (227).

No food storage recorded.

Nutrition and Energetics

As seasons progress beyond summer, proportion of vegetable matter in diet increases until it reaches 88% of diet during winter (219). To maintain red plumage, both males and females must ingest carotenoid pigments during fall molt; fruits and insects are high in carotenoids, while most seeds are poor sources (228). However, commercial bird seeds (e.g., red and white millet and sunflower seeds) provided to wild-caught cardinals held in captivity during molt, contained sufficient carotenoids to allow cardinals to produce red plumage, but plumage was duller and lighter (less saturated) than plumage of non-captives (74, 73); also see Appearance: Plumages: Proximate Control of Coloration. Fruit was the major dietary component in fall during molt in an Ohio population: wild grapes (Vitis spp.) 31%, other fruit 27%; unknown 18%; insects 16%; and seed 8% (based on focal observational sampling of 30 males, each observed ≥ 30 minutes, recording what was being eaten every 5 minutes [29.25 observation hours; 229]). Eggshells from newly hatched young may be eaten (see Breeding: Hatching).

Mean digestive efficiency for two types of sunflower seeds, millet (Panicum miliaceum), and sorghum (Sorghum vulgare) is 80.4% (230); for four other seed types (round-headed lespedeza (Lespedeza capitata), thick-spike gay feather (Liatrus pycnostachya), maximilian sunflower (Helianthus maximiliani), and sawtooth sunflower (H. grosseserratus) in simulated winter conditions, gross energy of seeds used ranged from 4.94 to 6.92 kcal/g, metabolizable energy from 2.66 to 5.86 kcal/g, and efficiency to metabolize from 53.9 to 84.7% (231). Average time to remove husk and consume sunflower seed provided at bird feeders was 36.5 s (232) and males were able to husk the larger seeds somewhat faster than were females (233).

Willson and Harmeson (234) used wild-caught individuals held in captivity to test seed preferences. Seeds and birds were collected from the same area around Urbana-Champaign, Illinois. Seeds tested were foxtail (Setaria faberi), hemp (Cannabis sativa), smartweed (Polygonum pensylvanicum), and ragweed (Ambrosia trifida). At room temperature, most individuals chose foxtail seeds first and then hemp seeds, based on number of seeds chosen. That preference was reversed at 0°C. However, based on weight in diet, hemp and then ragweed seeds made up a larger portion at both temperatures. These were the two seeds highest in protein and lipid content, calories per kernel, and rate of caloric intake (taking into account handling time and metabolic efficiency). The authors suggested that cardinals may select more foxtail seeds when held at room temperature because of the shorter handling time; they suggested in another context that shorter periods of inattention to potential predators (a potential consequence of shorter per-seed handling times) might be beneficial when constraints of caloric intake are relaxed.

Metabolism and Temperature Regulation

Zone of thermal neutrality for subspecies cardinalis is 18–33°C from December–April and 24–34°C from May–July, with corresponding metabolic rates of 2.65 and 2.61 ml O2/g/h, respectively; body temperature 41–42.5°C during the day with moderate activity, and 38.5–40°C at night with inactivity and sleep (235). Can withstand up to 50°C in still air at night when exposed to clear sky. At lower temperature limit, increases metabolic rate, decreases water loss, fluffs feathers, and tucks bill under scapulars to withstand –40°C with blackbody conditions in still air (236). For subspecies superbus, higher summer thermoneutral zone found (29–42°C), with lower corresponding metabolic rate of 2.2 ml O2/g/h; when ambient temperature was the same as body temperature, dissipated 100% of body heat through evaporation, losing less water and dissipating more heat than did subspecies cardinalis at temperatures above its thermoneutral zone (237). No evidence of torpor, but overall temperature rhythms are depressed during the winter, potentially saving animals 10–16% in daily energy expenditure (238). Resting metabolism (subspecies not identified) can increase when experiencing elevated temperatures in desert environments (239).

Recent evidence suggests that metabolic ceilings can vary between breeding and non-breeding seasons. Northern Cardinals studied in southwestern Ohio were found to have increased daily energy expenditures and higher summit metabolism in winter than during the summer breeding period (102). Seasonal changes in mass or oxidative capacity of skeletal muscle did not occur. Energy expenditure at midday during winter was higher than in summer, and overnight energy expenditure during longer winter nights was nearly double the amount of energy required for shorter summer nights (102).

Body mass and body fat were higher in Northern Cardinals measured in winter than in summer in an Ohio population (102). Estimates of average fat available at dawn during winter in Tennessee and Indiana populations was sufficient to maintain a metabolic rate of 2.5 times the basal metabolic rate for a mean of 11.1 h ± 1.8 SD (n = 20; based on n = 11 for Tennessee, n = 9 for Indiana); in a southeastern Michigan population, for a mean of 4.0 h ± 2.1 SD (n = 7); and for 1.0 h ± 1.1 SD ( n = 13) in an Alabama population (where warmer winter temperatures would render a metabolic rate 2.5 times the basal rate unnecessary for daytime thermoregulation) (M. Burger, unpublished data). In the northern portions of their range, cardinals may be close to the limit of their ability to maintain thermal homeostasis (240). In a comparative study from Iowa, Michigan, Missouri, Indiana, Louisiana, and Alabama, M. Burger (unpublished data) measured lean body mass, organ sizes, body fat, triiodothyronine (T3) and thyroxine (T4) levels. Body fat levels were greater in the evening, and increased with latitude, except for birds sampled near the northern edge of the range. Lean body mass and dry organ mass increased with latitude and from east to west. Hormones may play a role in geographic differences and may be involved with acclimatization. Thyroxine was high in southern areas, low in midlatitude, and intermediate at the northern edge of the range; T3 increased with latitude. Levels of both T3 and T4 were higher in the evening.

Drinking, Pellet-Casting, and Defecation

Drinks by scooping water in bill and tipping head back. From Dawson (235), eastern subspecies loses 2.5 mg water/g/h through evaporation at 25°C and 20% relative humidity (calculated from line fit to 44 data points from 16 individuals measured between about 17 and 41°C). At moderate temperatures, cardinals cannot offset evaporative losses by metabolic water production; active evaporative cooling commences at 33°C, when the rate of evaporative water loss increases sharply. Need for access to drinking water or food with high water content may influence distribution in dry habitats.

A hand-raised 5–6 week old individual casted a pellet of millet husks and seeds (100); no other reports of pellet-casting.

Recommended Citation

Halkin, S. L., D. P. Shustack, M. S. DeVries, J. M. Jawor, and S. U. Linville (2021). Northern Cardinal (Cardinalis cardinalis), version 2.0. In Birds of the World (P. G. Rodewald and B. K. Keeney, Editors). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/bow.norcar.02