Herons are elegant birds that can be found near water sources like marshes, streams, lakes, and coastlines. Their activity levels fluctuate throughout the year as they migrate, breed, and raise young. Understanding when herons are most active can help birdwatchers know the best times to observe these birds.
Spring Migration
In spring, herons become more active as they migrate back to their breeding grounds. The exact timing depends on the region and species. In North America, most herons migrate north between March and May. For example, Great Blue Herons in Canada start migration in late February and return to nesting sites by early March. Further south in the United States, Great Blues may not return until April or May.
During migration, herons are actively flying during the day as they move between wetlands and other stopover sites. This offers excellent viewing opportunities to see these large birds in flight. Staking out wetlands along known migration flyways increases the chance of spotting migrating herons.
Courtship and Nesting
Once herons reach breeding grounds in spring, activity shifts to courtship rituals and nest preparation. Males arrive before females and begin displaying to establish nesting territories. Most herons build nests high up in trees, sometimes in large colonies with other heron species.
Great Blue Herons engage in elaborate courtship displays like erecting plumes, stretching necks up, and bill duels. Watching herons at a rookery offers a chance to observe these behaviors. By late April, most herons are actively building nests in preparation for eggs. Nest construction continues into May for some species.
Egg Laying and Incubation
In most regions, herons lay eggs in May or June. The timing varies by latitude, with southern herons breeding earlier than those further north. For example, Great Blues in Florida nest in February or March while those in Canada lay eggs in May.
Once eggs are laid, adult herons take turns incubating them. Their activity shifts to continuously sitting on the nest to keep eggs warm. However, adults still make periodic feeding flights to bring food back to the nest. Mid-spring is therefore a great time to spot herons fishing actively at local wetlands.
Raising Young
Heron chicks usually hatch in about a month. The parents stay very active finding food to feed the rapidly growing chicks. Adults make constant hunting forays, often leaving the nest simultaneously. They return with food held in their bill to regurgitate to the young.
Watching heron nests in early summer offers the chance to see adults flying back and forth feeding chicks. Bring binoculars to try and spot chick heads popping up from nests. GREat Blue Heron chicks fledge at around 2 months old when they take their first flights from the nest. Other species like Green Herons fledge faster at only around 3 weeks after hatching.
Post-Breeding Dispersal
Once the young fledge and leave the nest, heron colonies start to disperse. Adults and juveniles wander more widely seeking food. Wetlands and shorelines often see influxes of herons in mid to late summer as a result.
Herons may congregate in groups, sometimes even mixing species, to feed actively at rich food sources. Shorebirds often accompany them. This post-breeding dispersal results in some of the most active and visible heron feeding of the year.
Fall Migration
Most herons migrate south again in fall starting as early as August for some species. Different populations follow staggered migration schedules. In North America, September is a peak migration month when activity levels are high.
Look for groups of herons, often mixed species, stoping to feed at inland wetlands on migration. Coastal sites also host large numbers of migrating and staging herons in autumn. Morning hours often provide the most active heron flight as birds move between roosting and feeding sites.
Winter Activity Patterns
Some heron populations migrate long distances and vacate breeding areas entirely each winter. However, increasing numbers now overwinter, especially in mild southern climates. Even in cold areas, a few herons usually remain year-round if open water persists.
Herons exhibit reduced activity levels in winter as food becomes scarcer. However, they still must feed daily, especially on warmer sunny days. This results in lower activity than spring and summer, but wintering herons can still be observed stalking prey slowly in shallow wetlands.
Migration stopovers and rare freezes that concentrate fish bring spikes in winter activity. As lakes and ponds start thawing in early spring, herons become active and start preparing to migrate north again.
Summary of Heron Activity by Season
| Season | Activity Level | Behaviors |
|---|---|---|
| Spring Migration | High | Flying between wetlands and other stopover sites |
| Courtship and Nesting | High | Displaying, nest building |
| Egg Laying and Incubation | Moderate | Sitting on eggs; some feeding flights |
| Raising Young | Very High | Constantly flying to fetch food for chicks |
| Post-Breeding Dispersal | High | Actively feeding at wetlands in groups |
| Fall Migration | High | Flying and feeding at stopover wetlands |
| Winter | Low-Moderate | Slow stalking; increased by migrations/freezes |
Conclusion
Herons exhibit a wide range of activity levels throughout the year as they undergo important life cycle events like migrating, breeding, and raising young. Their activity peaks in spring during courtship rituals and nesting. It remains very high in early summer while provisioning chicks.
Autumn brings another spike in activity as birds prepare for fall migration south. Even winter sees moderate heron activity levels, especially on sunny days or during freeze events. Paying attention to heron biology and seasonal behaviors can help birders know when to look for these elegant marsh birds throughout the changing year.
