The Northern Cardinal, with its striking red plumage and cheerful song, is arguably one of the most beloved and recognizable birds in U.S. backyards. A year-round resident across much of the country, many bird enthusiasts believe they have a firm grasp on this charismatic species. However, as the peak of summer descends, the cardinal’s habits subtly shift, often leading to a puzzling decrease in sightings or a misunderstanding of their daily rhythms.

You might assume they’re less active, or perhaps even gone, but the truth is, the Northern Cardinal is merely adjusting to the season, revealing a secret summer schedule that’s rich with hidden activity if you know where and when to look. 

Photo by David Kanigan

Breeding and Raising Fledglings: Hidden in Plain Sight

This is the primary reason for their apparent disappearance. Cardinals have an exceptionally long breeding season, often raising several broods each year.

Intense Nesting Activity (and Secrecy)

Northern Cardinals are prolific breeders. Unlike many migratory species that have one, maybe two broods per year, cardinals can attempt two to three (and sometimes even four) broods in a single breeding season. This extended breeding period (roughly March to September) means they are almost constantly engaged in some phase of nesting throughout the summer.

The female, often with the male bringing some materials, constructs a cup-shaped nest, typically 3-10 feet off the ground. Crucially, they choose dense, thorny shrubs, thickets, or vine tangles. These locations offer camouflage and protection from predators, making the nest incredibly difficult for humans (and predators) to spot. Nest building can take 3-9 days, followed by a short break before egg-laying. 

Why you’re missing them – Even at this stage, the birds are trying to be discreet. Frequent, obvious trips with nesting material would draw attention to the location.

Photo by SaguaroNPS

The female lays 2-5 (usually 3-4) eggs, which are grayish-white with speckles. She alone incubates the eggs for 11-13 days. During this time, she is almost constantly on the nest, blending perfectly with her surroundings. The male’s primary role during incubation is to bring food to the incubating female and defend the territory. He might make quick, furtive visits to the nest with food, but otherwise, he’s busy foraging away from the nest site. His vibrant red color is a strong signal to rivals to stay away from the territory, but also a potential beacon for predators, so he avoids lingering near the nest.

Why you’re missing them – The female is virtually invisible on the nest. The male is making discrete trips for food or defending the territory from a distance. Their usual songs might be curtailed near the nest to avoid giving away its location.

After hatching, the nestlings are altricial (naked, blind, and helpless) and grow incredibly quickly. They demand constant feeding. Both parents switch to a diet almost exclusively of protein-rich insects and spiders for the nestlings. They’ll forage tirelessly for caterpillars, beetles, grasshoppers, and other invertebrates. While there’s a lot of coming and going from the nest, the parents are still trying to be as stealthy as possible, often approaching and leaving the nest from different directions or through dense cover. They are focused on efficiency: get food, deliver, dispose of fecal sacs, repeat.

Why you’re missing them – They are busy gleaning insects from foliage and the ground, away from your seed feeders. Their visits to feeders are opportunistic, quick stops for adult fuel, not the main focus of their day.

Cardinal nestlings fledge relatively quickly, often just 7-13 days after hatching. They leave the nest before they can fly well. These fledglings are clumsy, can’t fly strongly, and are highly vulnerable to predators. Their plumage is also duller, providing some camouflage. The male typically takes primary responsibility for feeding and caring for the first brood of fledglings. He guides them to safe spots, continues to bring them food, and teaches them to forage. This often allows the female to immediately begin building a second nest and lay a new clutch of eggs.

Why you’re missing them – The fledgling phase is when you might hear them the most (constant begging calls from hidden spots), but still struggle to see them. The male is constantly on the move, chasing after the demanding young, often deep in thickets or ground cover. He’s not perched conspicuously singing or waiting at a feeder.

Photo by A.G. Rosales

For rapidly growing nestlings and fledglings, protein-rich insects are paramount. Parent cardinals spend an immense amount of time foraging for caterpillars, beetles, spiders, and other soft-bodied insects. This means they are often foraging in trees, shrubs, and on the ground, away from your seed feeders. Fledglings often hide in dense thickets and shrubbery while their parents bring them food. They are clumsy and vulnerable, so parents keep them concealed. You might hear their insistent begging calls coming from deep cover, but struggle to spot the birds themselves.

After the first brood fledges, the female often immediately begins building a second nest and laying eggs, while the male takes primary responsibility for feeding the first brood of fledglings. This continuous cycle means the adults are almost constantly busy with parental duties, leaving little time for lounging at feeders or singing loudly.

Why you’re missing them – You’re looking for the bold, bright cardinal at your feeders or singing prominently. In reality, they’re often tucked away in dense vegetation, diligently hunting for insects, or quietly guiding their camouflaged young.

Photo by Skyler Ewing

Molting: A Time for Seclusion and Renewal

Molting is the process by which birds periodically shed their old, worn-out feathers and replace them with new ones. It’s an essential physiological process, as feathers are vital for flight. Worn feathers are less efficient, making flight more demanding. Damaged feathers lose their ability to trap air efficiently, compromising temperature regulation, which is crucial for surviving both heat and cold. Bright, healthy feathers are key for attracting mates and signaling fitness.

For Northern Cardinals, like many passerines, a complete annual molt typically occurs in late summer or early fall, often starting in July and continuing through August and September. This timing makes sense: it’s after the intense demands of breeding (when they can afford the energy expenditure) and before the onset of winter (when good insulation is paramount).

Growing new feathers is incredibly energetically expensive. Feathers are primarily made of keratin (a protein), so the bird needs to synthesize a large amount of protein and redirect resources from other activities. To conserve energy, molting birds generally become less active. 

Why you’re missing them – They may spend more time resting, preening (to help new feathers emerge from their sheaths), and less time in conspicuous foraging or singing.

As old feathers are shed and new ones grow in, the bird’s flight can be temporarily impaired. Missing flight feathers (primaries and secondaries on the wings, or tail feathers) make them less agile and slower, significantly increasing their risk from predators. While new feathers are growing, the bird’s plumage can look patchy or disheveled, potentially making them stand out more. To minimize this increased risk, molting cardinals often seek out denser cover, thickets, and areas with more protective vegetation. 

Why you’re missing them – They will avoid open spaces and may not visit feeders as frequently, or will do so very quickly and furtively.

Photo by Dax

Abundance of Natural Food Sources: Less Reliance on Feeders

As the U.S. summer progresses, the landscape explodes with a variety of naturally occurring food sources that are perfectly suited to the dietary needs of cardinals and their young. Summer is prime insect season. Caterpillars, beetles, grasshoppers, crickets, spiders, and countless other invertebrates are abundant. As previously discussed, insects are the primary food source for nestling and fledgling birds due to their high protein, fat, and moisture content, essential for rapid growth. Parent cardinals are tirelessly hunting these. Even adult cardinals, while primarily seed-eaters, supplement their diet heavily with insects, especially during breeding and molting, for the protein boost. 

If cardinals are busy gleaning insects from leaves, branches, and the ground, they have less immediate need for seeds from a feeder. They become very efficient at finding these natural protein sources. As summer progresses, many native and cultivated plants begin to produce ripe berries and small fruits. Examples include mulberries, serviceberries, cherries, dogwood berries, elderberries, raspberries, and blackberries. 

Why you’re missing them – Cardinals are enthusiastic fruit-eaters. If there’s a mulberry tree or a patch of wild raspberries nearby, they will spend considerable time there, sometimes ignoring seed feeders altogether.

As grasses, wildflowers, and weeds mature throughout the summer, they produce an enormous quantity of seeds. Many of these seeds are easily accessible to birds like cardinals, who will forage directly from the plants. Think of sunflowers, coneflowers, various thistle-like plants, and common weeds that grow in undisturbed areas. Nature is providing a far greater diversity of seed types than most feeders.

Why you’re missing them – While your black oil sunflower seeds might be a consistent favorite, the vast array of natural seeds available means your feeder is just one option among many, and often not the most novel or interesting.

Photo by Joshua J. Cotten

Adapting to Heat: Conserving Energy

For birds like the Northern Cardinal, which maintain a high body temperature (around 104-108°F) regardless of external conditions, summer heat in the U.S. presents a significant challenge. Unlike humans, birds don’t have sweat glands (except for a few, like ostriches, and even then, it’s not like human sweating). So, they rely on a suite of behavioral and physiological adaptations to regulate their body temperature and conserve precious water. This adaptation to heat strategy is a major reason why their activity patterns shift in July.

The Mid-Day Siesta: Reduced Activity

This is the most noticeable behavioral adaptation. Any physical activity (flying, foraging vigorously, singing loudly) generates metabolic heat. During the hottest parts of the day (roughly mid-morning to late afternoon), cardinals will significantly reduce their movement to minimize this internal heat production. You might see them perched quietly, often for extended periods, perhaps with their feathers slightly fluffed to allow air circulation near the skin, or even appearing to doze. This is their equivalent of us seeking air conditioning and relaxing.

Why you’re missing them – If you’re observing during these hours, you’ll see fewer birds moving around, fewer visits to feeders, and hear less singing. They are sitting out the worst of the heat.

Seeking Shade and Cooler Microclimates

Cardinals will retreat into the coolest, densest parts of your yard or local habitat. This means thick shrubs, the shaded canopy of mature trees, and areas with good air circulation but minimal direct sunlight. While they might forage on the ground, they’ll often do so in shaded areas. 

Why you’re missing them – This shade seeking makes them much harder to spot. They blend into the foliage, and their lack of movement means they won’t draw attention to themselves.

Photo by Aaron J Hill

Utilizing Water Sources: The Essential Oasis

Water is essential for hydration, especially as birds lose moisture through panting (if they engage in it, see below) and respiration. Splashing in cool water is an incredibly effective way for birds to rapidly lower their body temperature through evaporative cooling. As the water evaporates from their feathers and skin, it draws heat away.

Why you’re missing them – Bird baths become magnets. While other parts of your yard might be quiet, a clean, fresh, and shallow bird bath can be a hub of activity for cardinals (and other species) throughout the hottest hours. This is often the best time to observe them during the day.

Physiological Adaptations and Behaviors:

While not as pronounced as in some other species (like cormorants or owls), cardinals may engage in rapid, shallow breathing (panting) or vibrate the moist membranes in their throat (gular fluttering). This increases airflow over moist surfaces, promoting evaporative cooling through the respiratory tract. It’s a visible sign of heat stress. You might also observe cardinals holding their wings slightly away from their bodies, often with a noticeable gap between the wing and the flank. This posture exposes the less insulated areas under the wings to air, allowing for convective heat loss from blood vessels close to the surface. In more severe heat, wings might hang lower.

Why you’re missing them – If you’re consistently looking for them at feeders or in open areas during the middle of the day, you’ll likely be disappointed. Their heat-adaptation behaviors are far less conspicuous than their breeding-season singing or active foraging. You need to look closer and understand what you’re seeing.

Final Thoughts

When your summer cardinals seem to vanish, know that they’re likely just deeper in the shrubbery, diligently performing the quiet, essential work of summer: raising the next generation. This involves quieter, sneakier behavior as they protect their young, visit feeders less, and regenerate their plumage. Understanding these adaptations means you can adjust your own birding strategy for July. Instead of being frustrated by their apparent absence, you can appreciate the intricate ways Northern Cardinals cope with the summer heat, often finding them in new ways at unexpected times.