Another Interesting (Odd) Year at Butterfly Ridge

Yesterday we completed our final transect of 2025. And to say this year has been . . . interesting . . . would be a major understatement. The first third of the season was mediocre at best, much like I had predicted in 2024. The drought we experienced during the summer of 2024 I think led to decreased butterfly numbers for the early months of 2025. The butterflies we were seeing April through June of 2025 we mostly single brood species like the duskywings. These butterflies had concluded their caterpillar-hood by the time the drought had kicked in, so they were relatively unaffected by the drought. However, multi-brood species like the swallowtails were very slow to get going this year.

duskywing

However, our very wet spring and early summer had plants growing like crazy, and the few adult butterflies that came out in the spring had no shortage of nectar sources and foliage for egg laying. With all of the lush plant growth, caterpillars flourished. This led to large numbers of summer butterflies. So, much like 2024, this year was a tale of two seasons. While 2024 had a great spring and a horrible summer, 2025 was the opposite with a horrible spring and a great summer.

Tiger Swallowtails and Monarchs were in great abundance later in the summer. This was our best year for Tigers since 2019. We recorded 40 on our September, 2025 transect. The only month in our history that had a stronger showing of Tigers was August, 2019 when we documented 86. Monarch populations were very strong, with more monarch caterpillars and adults spotted than any year since 2020.

The graph above shows month-by-month how the 2025 transects compared to other years. You can easily see how the early months were mediocre while the later months were among our best ever. The graph below shows how the total number of butterflies this year compared to previous years, and this year CRUSHED all previous years. Who would’ve guessed after such a poor start!

The question begs, “What do we expect for next year?” The honest answer is that we have no clue! While we are back in drought conditions yet again, in our section of Ohio the drought of 2025 has not been as severe as the drought of 2024. Afterall, we still have Tuliptrees with leaves, which was not the case in early October of 2024. In addition, the drought of 2025 hit a little later than the drought of ‘24. Therefore, I expect this year’s drought will not be as impactful on next spring’s butterflies. Of course, an excessively unseasonable winter, either direction, could impact the spring butterflies. But we cannot predict that now.

Next summer’s butterflies will be determined largely by the weather in the winter and next spring. I think there is potential for a strong summer butterfly population, but there is a whole lot of time between then and now. And whether it is a good year or bad, we will continue to track the data, create habitat, and teach others to do the same!