Summer Birding – Understanding Breeding Season and Bird Behaviors

By Mic McCarty, Field Trip Coordinator/Tampa Audubon Board Member

Northern Cardinal, photo by Lisa Flannagan.

When the vibrant colors of spring migration have faded into the background, June brings a different kind of excitement to the birding world. The migration season winds down, and many birds settle into their breeding territories, engaging in a variety of fascinating behaviors. This period offers birders the opportunity to observe and appreciate the intricate and dynamic lives of birds as they raise their young.

Territorial Defense

One of the most prominent behaviors during the breeding season is territorial defense. Birds establish and vigorously defend their territories to ensure ample resources and safe nesting sites. I frequently see mockingbirds, thrashers and cardinals chasing off members of their own species. Be sure to look closely; the chase may be mating behavior!

Singing

Birdsong reaches its peak during the breeding season. Male birds use song to attract mates and signal their territory's boundaries. Some species, like the Carolina Wren, sing year-round. During mating season, I often hear seven or more wrens declaring their territory just before and after dawn.

Arguably, the best songster of the spring is the Brown Thrasher. Only then do I hear males singing in their distinctive style. The thrasher will sing a phrase and repeat it once, and only once. Then, he fills the air with another doublet, and then once again with yet another new song. One study I read asserted that the Brown Thrasher may hold the world record for the most bird song—1500 songs! Watch for thrasher males sitting high up in their territory, filling the sky with new tunes.  

Mating

Mating rituals are another captivating aspect of bird behavior. Mockingbirds perform an acrobatic, swift flight through the territory, male chasing female, often accompanied by the exchange of soft hew calls. I’m certain that I have mistaken mockingbird chases for territorial defense, so I will be watching carefully to see! Is that a territory dispute or a mating display?

Incubating

After mating, the female typically takes on the role of incubating the eggs. During this period, she remains on the nest, keeping the eggs warm and protected until they hatch. Incubation periods vary among species, but usually last several weeks.

Brooding

Once the eggs hatch, brooding begins. The parents work together to keep the chicks warm and safe, often taking turns covering them with their bodies. This period is critical for the survival of the young, as they are vulnerable to predators and harsh weather conditions.

Feeding Young

Feeding the young is a demanding task that requires constant attention. Parents tirelessly forage for food, bringing back insects, seeds, or other nourishment to their hungry chicks. Observing the feeding routine can be both heartwarming and awe-inspiring, highlighting the dedication and care birds provide for their offspring. The parents continue to feed their young after fledging, so watch for this in your yard and report it in eBird with a breeding code “FY” (feeding young).

Mockingbird Baby Dispersal versus Cardinals' Babies Helping

Different species exhibit unique post-nesting behaviors. Mockingbird fledglings typically disperse shortly after leaving the nest, venturing out to establish their own territories. In contrast, young Cardinals often stay close to their parents and may even help with raising subsequent broods. These contrasting strategies reveal the diverse approaches birds take in ensuring the survival and success of their offspring. You must look carefully to discern whether the mockingbird you see is a fledgling (they have spotted breasts) or adult. Immature cardinals look like their moms but have grey beaks.

Mobbing Would-Be Predators

Mobbing is a collective defense mechanism where birds gather to aggressively harass potential predators. Mobbing can involve loud calls, dive-bombing, and persistent chasing. You may witness this behavior by crows and jays, who work together to drive away a Red-tailed Hawk. A mob members may then become another mob’s target. Last week I witnessed two Blue Jays and three mockingbirds mob a Fish Crow. One moment the crow can be part of a mob; next it can be the target of a mob!

Further Reading

For those interested in diving deeper into bird behaviors during the breeding season, What It's Like to Be a Bird by David Sibley and the Peterson Reference Guide to Bird Behavior are excellent books. These guides offer comprehensive insights into the fascinating world of avian life, helping birders understand the motivations and actions of the birds they observe.

Summer birding during the breeding season is a rewarding experience that showcases the dedication, complexity, and beauty of avian life. By observing these behaviors, birders gain a deeper appreciation for the intricate lives of birds and the challenges they face in raising their young.