20 Aug Journeying Outside Dinosaur National Monument

Now that I have a few weeks of butterfly field work experience under my belt, I am beginning to spread my wings (butterfly pun sincerely intended) to conduct field work in areas outside of my main field site in Dinosaur National Monument. Since little is known about monarch butterflies in the greater Uintah Basin area of Northeastern Utah, I have traveled around the region to survey for monarchs and milkweed. So far, I’ve gone to a private urban property, a private ranch, a state wildlife management area, and a BLM historic site. In the future, I’ll be surveying other lands outside the Monument as well as more remote parts of Dinosaur. I even will be going on a river rafting trip through Dinosaur in September to look for monarchs within the deep canyons of the Green River.

Utah has several different species of milkweed, and all of the different places I’ve surveyed so far have had showy milkweed. From what I gather, showy milkweed is likely to grow in wetlands, riparian areas, roadsides, and irrigated areas. In Dinosaur, but not the others areas, I’ve also found swamp milkweed (which is found in, you guessed it, swampy areas), and pallid milkweed (in the Monument’s desert ecosystems). You can look at this page from the Xerces Society and scroll down to the regional milkweed guides if you want to learn about what types of milkweed might be present in your area.

Even though they have milkweed, many of the other sites don’t have nearly as many monarchs as I’ve seen at Dinosaur. I figure that’s because milkweed alone isn’t enough to make good monarch habitat. Since milkweed is monarchs’ larval food plant, milkweed has to be present for monarchs to reproduce. But monarchs also need trees to roost in overnight, water, and blooming flowers for nectar. Without nectar, monarchs can’t eat and get the nutrients they need to fuel their reproduction or migration.

My main study site in Dinosaur National Monument is lucky to have all sorts of blooming nectar plants – milkweed plus sunflowers, asters, Joe Pye weed, Rocky Mountain bee plant, thistles, and more – and that’s probably a big reason why it has so many monarchs. (Pictured are blooming sunflowers and Joe Pye weed at my study site in Dinosaur. There’s enough purple and gold around there from the flowers that the scene practically looks like a Lakers game). At Stewart Lake Wildlife Management Area, meanwhile, there were whole fields of blooming sunflowers and Rocky Mountain bee plant and many monarchs flying about and feeding. Elsewhere, there may be huge patches of milkweed in the middle of mowed agricultural fields or alongside highways elsewhere. However, it’s hard to imagine that monarchs visit those patches too much once the milkweed is done blooming and there’s no nectar plants around. I found lots of monarch eggs and larvae on the private ranch in a patch near the lawn where there was blooming plants, but any signs of monarch breeding were hard to find down in the milkweed patches in mowed alfalfa fields.

Going outside Dinosaur has made me really appreciate what the Monument has. I can see 30 monarchs in just a few hours at my main site in Dinosaur, but many places outside the Monument just don’t have that many nectar plants and they might have just a few monarchs coming by. Further, in Dinosaur I’ve recaptured monarchs days and even weeks after I originally caught them. This means that at least some monarchs are hanging out in my study area for a while and not just passing through. In such a nice habitat, some are probably staying to breed, lay eggs, and live out their lives. It’s great that the little swampy area occurs in a national monument and will be protected long-term, conserving this awesome bit of monarch habitat.