what is going on at night on the Ozark chinquapin?
by A. J. Hendershott
Have you ever considered what takes place in and around trees while you sleep? Sure, we all know about owls, racoons and even flying squirrels, but if you are like me, you probably don’t give it much attention. Thanks to some new research, that lack of attention is changing. Specifically, research is focusing on the Ozark chinquapin tree which seems to be center stage for attracting nighttime activity in the Ozarks. Scientists are examining what is pollinating the Ozark chinquapin at night. This activity has spurred on some additional visitors that we don’t know much about.
In a 2017 thesis at the University of Arkansas Fayetteville, Colton Zirkle discovered that insects played an important role in pollinating Ozark chinquapin trees. Zirkle’s effort was groundbreaking as most text considers trees and shrubs in the genus Castanea wind pollinated. Castanea includes chinquapins and chestnuts all around the world. While wind is still important to pollination for the Ozark chinquapin, Zirkle was able to validate pollination by insects is necessary for maximized seed production. For details on his project visit “The Effect of Insects on Seed Set of Ozark Chinquapin, Castanea ozarke” by Colton Zirkle (uark.edu).
I discussed this research with Zirkle as it was the first of its kind for the Ozark chinquapin. During that conversation he said something I considered profound.
“Chinquapin flowers are white and white flowers tend to attract nighttime pollinators,” Zirkle said.
This intrigued me. The research Zirkle conducted was done during the day due to the nature of his method. While he was out there, he collected insects which he detailed in his thesis. As a good entomologist Zirkle understood this was just the beginning of the story and nighttime work was next in line.
Moths
I think most of us are familiar with a moth’s attraction to porch lights and other artificial light forms. They are active primarily at night but how much do we really know about moths and what they are up to? I found out. Quite a lot apparently.
According to the Smithsonian Gardens webpage article entitled The Why, What, When, Where, Who, How of Pollination, moths are a pretty important pollinator, “most moths go unnoticed even though they outnumber butterflies 10 to 1. Why? They are often active at night and dull in appearance. Night-blooming flowers have sweet scents and white or cream colored blossoms that reflect the moonlight to attract moths after the sun sets.”
More detailed research was conducted on the subject of nighttime pollination in the United Kingdom and they found some surprisingly high activity at night. In an article for The Conversation, Richard Walton stated, “our new research found that moths visit a surprisingly diverse range of plants at night. The work these nocturnal pollinators do is bigger and more complex than many people realized, and because it happens under the cover of darkness, it’s often largely invisible to human eyes.”
There was certainly some overlap but, in some cases, the nocturnal pollinators visited plants that daytime pollinators frequent less often. This emphasizes the importance of the night shift when it comes to pollination.
The Ozark chinquapin seems to be one of these plants. We know that many species of flies, wasps, bees, beetles and moths visit the tree attracted to its fragrance, nectar and pollen during the day. Apparently, the night shift has a lot to offer the tree in terms of pollination services as well.
Beetles
Smithsonian Gardens webpage also touched on beetles as nighttime pollinators and had this to share, “beetles are referred to as “mess and soil” pollinators. Less elegant than other pollinators, beetles blunder their way through delicate blossoms searching for food, a mate, or perhaps the bathroom. {yes, they do “that” in flowers}. Beetles frequently visit magnolias and flowers close to the ground.” Ninebark (a woody shrub with white flowers), blackberries and even apple blossoms are attractive to beetles at night.
Beetles like the goldenrod soldier beetle frequent chinquapin blossoms during the day. Do they do the same at night? Are there other species of beetles out there doing the work of pollination? We have a lot to learn about which beetle species visit the tree at night.
Hobbs State Park
To fill in that gap, employees, and volunteers at Arkansas’ Hobbs State Park are taking advantage of their location and all its amenities. The park itself has remnant populations of Ozark chinquapins and they are actively managing groves of blight resistant chinquapins on park property. So, the plant and animal relationships may be loosely intact which is worthy of study. Hobbs’ staff and volunteers have been collecting and photographing invertebrates on the chinquapin flowers for identification.
Lilia Stemet is a graduate research assistant at the University of Arkansas in Fayetteville, Arkansas and is furthering our understanding of insect activity on the Ozark chinquapin trees. During her October 19, 2024, presentation at the annual Ozark Chinquapin Foundation public meeting she shared some details on invertebrates visiting Ozark chinquapin trees at Hobbs State Park. In that report she indicated out of 234 invertebrate species collected, 96 had nocturnal habits while 13 were active at dusk.
Stemet further informed the crowd that of that 234 insects collected 100 were butterflies, and moths, 58 beetles, 34 flies, 26 bees and wasps, 14 true bugs and 2 lacewings. Furthermore, of the 100 butterfly and moth group was composed mostly of moths, with 35 species of moths and 15 species of butterflies.
Stemet’s work at Hobbs indicates beetles and moths are most active at night with butterflies, flies and bumble bees conducting some visits in the predawn hours.
Cape Girardeau Nature Center
Roxane Magnus and Karin Pelton are both volunteers at the Cape Girardeau Nature Center and they have worked over the past two summers to observe, collect, identify and photograph insects associated with the Ozark chinquapins planted on the site. As a contrast to the work going on at Hobbs, the trees at Cape Girardeau are not part of a remnant population and the insects utilizing the trees are simply taking advantage of what lives there.
Magnus and Pelton have documented 7 species of butterflies and moths with several species that Magnus is still working through to identify. In addition, Magnus has identified 8 species of beetles, 4 flies, 6 true bugs, 1 lacewing, 1 thrip, 1 saw fly and many assorted species of spiders. One bee was identified as Andrena obscuripennis, which is a type of mining bee that has only been recorded in Missouri one other time near the Mississippi River.
While Magnus has more species to work up, a pattern is emerging similar to the species assemblage Stemet is working with. Magnus considers moths, beetles, wasps and flies potential pollinators but wants to do more research. She also recognizes the importance of paying attention to the night shift. She and Pelton have been and will continue to do insect monitoring at night and see if different night periods have different insects present.
Nightjars and Bats
Its more than the insects on the trees at night. OCF President and founder Steve Bost was working a chinquapin orchard in Southeast Missouri in 2021 and noticed he had scared up a whippoorwill hiking up the ridge. He encountered this bird several times that summer and realized the bird was likely nesting in that area. Whippoorwills are a member of the family Caprimulgidae including nighthawks and chuck-will’s-widows and are known for their lack of nest building. Collectively they are called nightjars, and females simply lay two cream-colored eggs in the leaf litter and count on camouflage of the parent to keep them concealed.
One interesting fact is that nesting activity may be timed by these birds as if they had a lunar calendar. It takes the eggs 20 days to hatch. Egg-laying is timed so that the young hatch about 10 days before a full moon, allowing the parents to forage all night long to feed their hungry chicks. Whippoorwill parents catch bugs and regurgitate them for the chicks. The full moon maximizes light for the parents as they fly along insect laden areas feeding their chicks.
Since whippoorwills feed primarily at dawn and dusk, moths make up a huge portion of their diet. They will also consume beetles and other night active insects on the wing.
After Bost observed those whippoorwills, he began to put things together but not until he had a late workday run into the night. Steve and his daughter Leslie were working at that same orchard well into the evening. They were working on pollination crosses which is timely in nature. They were trying to maximize their time by working as long as they could. Leslie was working by a headlamp after the sun set, and happened to notice something swoop near where she was working. She mentioned it to her dad. Before the evening work was completed, they figured out it was bats.
That made a lot of sense. The bat was flying around catching insects and since the chinquapins attract night pollinators, they likely were concentrating pollinators like an all you can eat buffet for bats.
It was after this observation Steve, began to postulate why that whippoorwill was nesting so close to the chinquapin grove. Its first clutch of chicks was being fed insects attracted to the white catkins of the chinquapin in the moonlight.
“I have always been amazed at how this tree impacts so many species and I wonder if it impacts the ecology of what goes on in the nighttime as well,” mused Bost.
Dawn Approaches
As we wrap up this look at the night shift surrounding the Ozark chinquapin, we can see clearly that there is a lot to be learned about what goes on after dark. We are learning what questions to ask and are beginning to chip away at them. The future looks bright as we continue to learn more about this species of conservation concern. We know this tree has a link to a variety of wildlife species and it looks like that list is only going to grow. This tree is planted more and more every year, and this provides the opportunity to reconnect to other species that perhaps have not benefited from its presence for decades. The reality is we have a lot to learn and so much to gain by returning this tree to its original range. As we learn more about the night shift associated with the Ozark chinquapin tree it helps us understand how much good we are doing for the ecology of our forests.
References:
The Why, What, When, Where, Who, How of Pollination – Smithsonian Gardens (si.edu)
Richard E. Walton, Carl D. Sayer, Helen Bennion and Jan C. Axmacher. Published:13 May 2020https://doi.org/10.1098/rsbl.2019.0877 Nocturnal pollinators strongly contribute to pollen transport of wild flowers in an agricultural landscape | Biology Letters (royalsocietypublishing.org)
Moths do the pollinator night shift – and they work harder than daytime insects (theconversation.com). Richard Elton Walton, Postdoctoral Research Associate in Biology, Newcastle University