Cardinals are iconic backyard birds known for their bright red plumage and melodious songs. They can be found across much of North America and are a favorite among birdwatchers. Cardinals are non-migratory, meaning they live in the same areas year-round. This means they need to build nests at the appropriate time of year to raise their young before winter arrives.
Nesting Season
The nesting season for cardinals varies across their range, primarily depending on latitude and climate. In general, cardinals build nests and produce broods between March and August. However, their peak nesting activity occurs between April and June.
Here is a breakdown of when cardinals nest by region:
| Region | Nesting Season |
|---|---|
| Southern U.S. (e.g. Florida, Texas) | March – August |
| Midwest U.S. (e.g. Missouri, Ohio) | April – July |
| Northeast U.S. (e.g. New York, Maine) | May – August |
| Northwest U.S. (e.g. Washington, Oregon) | May – July |
| Canada | May – August |
As you move further south, cardinals begin nesting earlier in the spring. Further north, shorter summers mean nesting starts later and ends sooner. But the core months of April through July are ideal for cardinals across most of their range.
Why Spring and Summer?
There are a few key reasons why cardinals build nests during spring and summer:
- Food availability – Insects, seeds, and berries vital to breeding cardinals are more abundant in spring and summer.
- Favorable weather – Warm temperatures help baby birds develop and survive outside the nest.
- Long daylight hours – More daylight facilitates more time for the parents to find food.
- Predator avoidance – Lush vegetation helps conceal nests from predators.
The convergence of these factors makes spring and summer ideal for cardinals to breed. The moderating temperatures, wealth of food resources, and concealment cover allow cardinals their best chance to raise and successfully fledge young.
The Nesting Process
Cardinals go through a successive process each spring and summer to build nests and raise young:
- Nest site selection – In early spring, mated pairs scout for ideal nesting spots, often picking a shrub or small tree.
- Nest building – Using twigs, leaves, grasses, and bark strips, the female builds a sturdy, cup-shaped nest over 3-9 days.
- Egg laying – A clutch of 3 or 4 eggs is laid, one per day. The female incubates them for 12-13 days.
- Hatching – Eggs hatch in the order laid, with both parents feeding the chicks.
- Fledging – After 9-11 days in the nest, chicks fledge but remain dependent on parents.
This cycle is often repeated for 2-3 broods per season. Some late nests may be abandoned as winter nears and resources decline.
Ideal Nest Sites
Cardinals prefer nesting sites that provide stability, concealment, and access to the surrounding habitat:
- Sturdy branches in shrubs or small trees up to 15 feet high
- Well-concealed among dense vegetation, close to trunk or stem
- Evergreen shrubs provide year-round cover
- Access to open ground to forage for food
- Near a water source like a stream or pond
Backyard cardinals often nest in shrubs near feeders, taking advantage of a reliable supplemental food source. Other common nest sites include rosebushes, honeysuckle, dogwood, and lilac shrubs.
Nest Construction
The female cardinal builds the nest without help from the male. She weaves together a sturdy basket up to 3 inches tall and 4 inches across, using the following materials:
- Twigs and strips of bark for the base
- Grasses, leaves, vines, and stems to form the cup
- Shredded bark, roots, or feathers to line the interior
- Bound with spider silk and pine needles
This dense construction helps insulate and protect the eggs and chicks. The female may build a new nest for each brood, or reuse and renovate old nests from previous years.
Defending Nest Sites
Cardinals are highly territorial during the breeding season. Both the male and female will aggressively defend the area around their nest from intruders:
- Chase away other cardinals entering their territory
- Attack potential nest predators like squirrels and snakes
- Threaten humans that get too close to the nest
- Give alarm calls to signal their mate if a threat is detected
Nest defense helps ensure their eggs and vulnerable chicks remain safe. But it’s best for your own safety to respect their boundaries and observe cardinals from a distance during nesting season.
Co-Parenting Responsibilities
Cardinals exhibit remarkable coordination as both the male and female participate in raising young:
- Female: Builds nest, incubates eggs, broods hatchlings
- Male: Defends territory, brings food to female while nesting
- Both: Feed and care for hatchlings and fledglings
The female typically devotes herself to nesting duties and is fed by the male. But both sexes work together once the eggs hatch, taking turns to find food and keep the chicks nourished until they fledge.
Conclusion
In summary, cardinals time their nest building and breeding to coincide with the plentiful resources of spring and summer. This ensures the best chance of survival for their vulnerable young. The specific months may vary across their range, but April through July are peak times for cardinals to build nests and raise broods before winter returns again.
