Climate change and mule deer habitat

In past columns, I’ve shared information regarding climate change and the measurable impacts that are occurring. The impacts are measurable, and the science on climate change is being documented around the world. Back in June 2017, the column was about tree species migration. The most recent column provided information about the declining populations of songbirds.

This column, we will read what researchers at the University of Wyoming are doing. Their published work addresses Climate Change impacts on mule deer habitat and migration. The research recently appeared in Global Change Biology. The paper shows that drought has a great influence on green-up of habitats that mule deer migrate through. Drought greatly shortens the annual forage mule deer need to sustain themselves through the year, especially during winter months.

The university website states, “This research shows that climate change can alter the underlying distribution of food resources by compressing the time when optimal forage is available, which reduces the benefit of migration,” writes Ellen Aikens, a 2019 graduate of the Wyoming Cooperative Fish and Wildlife Research Unit at University of Wyoming. “This work highlights an emerging threat to migratory mule deer and likely many other migratory species.” Aikens also says that mule deer can follow a green wave of newly sprouted springtime plants in wet years and it lasts for about four months. Deer get a major portion of their forage for the entire year by following what she calls “a green wave of plants.” This green wave progresses in orderly fashion from low winter ranges to high summer mountain range. In drought years, the green wave is half as long. Good forage is spotty, as well.

“This study has revealed an underappreciated mechanism by which climate change is altering green-up and making migration less profitable for ungulates,” writes Matthew Kauffman, director of that Wyoming unit and a co-author of the study. “We are identifying a new threat for migrating ungulates, which will likely worsen as climate change continues.”

Weather data for the month of July 2020 was taken from my home weather station. Precipitation was on the low side at 0.08 inches. It all occurred during the first few days of July. For this decade, the driest for July were 2003 and 2017, both with zero readings. The wettest July was 1993 with 2.94 inches; the all-time mean is 0.46 inches.

Once again, July doesn’t disappoint with high temperatures. We had four days that exceeded the 100˚F mark: the 27th, 29th, 30th and 31st. The high was on the 30th with 104.1˚F. The low was 48.3˚F on the 13th. Our mean was 74.8˚F. The all-time high was 113˚F in 1939. The all-time low was 32˚F in 1983, and the all-time mean for July is 73.1˚F, which we exceeded by 1.7˚F this year. 85 years of local weather records show that of three summer months — June, July and August —July dominates as the warmest.

The International Space Station (ISS) was visible for several days during July. I hope you had a chance to witness one or all of the fly-overs. During the month of August, we can turn our eyes skyward and here’s what we should be seeing, according to our friends at EarthSky.com: “Four of the 5 bright planets are visible in the August 2020 sky. You’ll notice bright Jupiter and Saturn near each other for most of these August nights. Red Mars rises in the east at mid-to-late evening, lighting the nighttime until dawn. Venus, the brightest planet, dominates the eastern sky in the hours before sunup.”