In the last few years, Oregon experienced extreme fluctuations in temperature; this large fluctuation does not come without consequences. Day-to-day weather patterns are completely thrown off. It’s raining too much or too little. And heavy snow is falling when it should not.
These atypical weather events pose a problem for animals who rely on weather signals to guide their migration patterns and life cycles. Their survival hangs in the balance of this climate change-induced weather catastrophe.
The 120 different species of birds who occupy the Delta Ponds in Eugene, Oregon, are no exception. Community members enjoy using this 150-acre waterway for recreational purposes, including bird watching. The city funded a massive restoration period for the ponds from 2004 to2012. These efforts created a biologically diverse home for the birds and other animals to rest, socialize, eat and reproduce.
In the first half of 2019, Eugene experienced a double whammy of harmful weather. The city accrued almost 2 feet of snow in one week of February. This amount is rarely seen in one month in the peak of winter. In addition, in April heavy rains led to flooding in parts of Eugene, including Delta Ponds. This flood was caused by a “Pineapple Express,” a Hawaiian storm that moved to the Pacific Northwest. Typically, this weather phenomenon occurs at the beginning of December, not four months later in the thick of spring.
Ecologists with the City of Eugene do not regularly collect data on bird diversity or abundance in local natural areas, but despite the lack of data, some locals are still concerned for the survival of birds in the area. “I'd say it gets really difficult to assert anything definitively or scientifically right now,” said Jim Maloney, an executive board member for the Lane County Audubon Society and scientist who worked for the Eugene Water and Electric Board for 20 years. “Aerial insectivores are really in precipitous decline. If I were going to speculate, I would say those species are going to be hit this year because of the impacts of the snow and the flooding on local insect populations. Our local swifts and swallows will have a much-reduced food source.”
In Maloney’s opinion, a double hit of weather anomalies such as this year’s snow storm and the spring flood points to climate change at work. Robert Dugger, an ornithologist at Oregon State University, disagrees. He said, “Attributing any one instance, one storm event, any one colonies' fate to something like climate change is a very difficult thing to do.” Scientists cannot definitively say whether or not the extreme weather events occurring at the Delta Ponds are a product of climate change. Decades of detailed observations and data on the Delta Ponds are needed to truly confirm that weather-related habitat degradation is negatively impacting the birds.
In 2016, an ice storm that totaled nearly 9.5 million dollars in damage swept over Lane County. The ice not only destroyed human property, but also damaged the cottonwood trees in the Delta Ponds. Herons raise their young in cottonwoods, so they were faced with a challenge that awoke their survival instincts: where to build their nests. Eugene natives can now find them in conifer trees outside of the Delta Ponds.
Even though birds like the herons are having to adapt because of these weather patterns, some scientists are still unconvinced that these events are bad for the Delta Ponds’ bird populations in the long run. Dugger said, “Are great blue herons a good indicator of climate change? Probably not. There's nothing you could collect on a day-to-day basis from year to year that is particularly compelling.”