Life on our South Jersey lavender farm offers many seasonal rhythms, and one of the most rewarding is watching the bluebirds that return to nest each spring. Each season, our bluebird trail provides a glimpse into the challenges and triumphs these beautiful native songbirds face. This year brought unusual weather patterns that affected both nesting behavior and brood success. Here’s a look at our findings from the 2025 season.
Early Nesting and Cold Spring Weather
Nesting began earlier than expected—at the end of March. Typically, female bluebirds lay one egg per day, but this spring’s cold, wet snaps disrupted that rhythm. Instead of steady daily laying, we observed gaps of two to even five days between eggs.
We believe these elongated laying periods contributed to a portion of eggs not hatching. Bluebirds rely on consistent weather for strong, synchronized broods, and this year’s chilly start caused some early struggles.
Bluebird nest with an unhatched egg.
Summer Heat Waves and Smaller Clutches
While spring slowed things down, summer introduced a new challenge: heat waves in June. Normally, bluebird clutches average five eggs, but this season we saw several nests with only four eggs laid. It appears that extreme heat may have stressed the birds, resulting in smaller broods.
Summer bluebird nest of 4 babies
An Earlier End to the Season
Another unique pattern we observed this year was how quickly the season wrapped up. Our last nests were banded at the end of July and fledged in early August. In comparison, last year we were still banding nests in early September, with fledglings leaving later that month.
We’re not sure what caused this earlier end to the season, but it’s something we’ll be keeping notes on as we continue to monitor the trail.
2025 Bluebird Trail Numbers
Despite the weather challenges, our bluebirds had a remarkably successful year:
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Total Eggs Laid: 58
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Total Hatched: 51 (87.9% hatch rate)
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Total Fledged: 50 (98% fledge rate)
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Overall Success: 86.2% of eggs laid fledged young
While we did see 6 eggs not hatch and 2 nestlings lost, the high fledge rate shows that most of the chicks who hatched grew strong enough to leave the nest successfully.
Here is a break down of our numbers at each box
Bluebird banded and handled by our County Coordinator
Preparing for Winter
Unlike many songbirds, Eastern Bluebirds do not migrate. They stay local throughout the year, often flocking together during the colder months. As fall approaches and the weather becomes consistently cool, we’ll be winterizing our nest boxes—usually at the end of October—to give the birds safe shelter during winter.
If you’d like to learn more about how to support bluebirds through the cold months, [click here to read our full article on helping bluebirds in winter].
Reflections and What’s Next for Our Bluebird Trail
As we reflect on this year’s trail results, we’re grateful for the resilience of the bluebirds despite the unpredictable weather. From cold snaps that stretched out egg laying to summer heat waves that limited clutch sizes, these birds showed remarkable adaptability. Watching them grow, hatch, and fledge is always a reminder of nature’s balance and determination.
We look forward to welcoming the bluebirds back to the trail next season and continuing to share their journey with you. Each year teaches us something new, and we can’t wait to see what lessons next year’s bluebird season will bring.
