Newsletter of the Columbia Audubon Society | October 2018 | Volume 61, Number 2
– by John Besser
Now that summer’s heat and humidity are finally behind us (let’s hope), October brings a flurry of activity from Columbia Audubon. There are lots of opportunities to get involved in a wide range of CAS events this month:
ASM Meeting: Technically, this happened on September 28-30, but I hope that many Columbians took advantage of this opportunity to show off our favorite local birding hotspots (and maybe find some new ones) in the company of friendly, expert birders from across the state. The meeting offered presentations on Friday and Saturday night, and a keynote speaker and banquet Saturday night, but especially featured a wide variety of birding field trips throughout the weekend.
Columbia Wilderness Sanctuary: On Tuesday morning, October 2, Edge Wade will lead a field trip to a hidden gem in the middle of Columbia on the banks of Hinkson Creek. This area is largely unknown except to the neighbors, but it’s likely to be in the news this fall, as the city plans to construct a new segment of the citywide trail network through this area. Contact Edge Wade for more information.
Band with Nature: This three-day event (October 8th, 10th, and 12th) is CAS’s biggest education initiative, and volunteers get a chance to share as hundreds of area second-graders experienced the wonder of birds up close and personal (read about last year’s event here). Contact Bill Mees if you’re interested in volunteering for a morning, an afternoon, or both.
‘Big Sit’ at Eagle Bluffs: This is a relatively new type of field trip for Columbia Audubon, and it’s the October event I’m looking forward to the most. The idea of a Big Sit, as popularized by the magazine Birdwatchers Digest, is to see as many birds from one location as possible during one calendar day. This is a group event, and you can spend as much or as little time at the site as you want. Our Big Sit will happen on Sunday, October 14 at the cul-de-sac at the end of the road at Eagle Bluffs Conservation Area. This spot offers great views of a variety of bird habitats, including the open marsh of pool 14, mature riparian forest on the banks of the Big Muddy, and the picturesque limestone bluffs along Perche Creek. During last year’s inaugural event, favorable winds along the bluffs led to a parade of Peregrine Falcons cruising south past the site — our group saw 18 on the day! Contact Eric Wood for more information.
The pace slows down a bit in the second half of October, but we will still have plenty to do. Our October chapter meeting will be held at the Unitarian Church at 7:00 p.m. on October 17. Allison Vaughn, CAS board member and land steward for the Missouri DNR’s State Parks division, will share some of her extensive knowledge of birds and bird habitats in Missouri state parks. The last event on our October calendar is a field trip to Rocky Fork Lakes Conservation Area on Saturday October 20, led by Greg Leonard, one of Columbia’s best birders and a new member of the CAS Board of Directors.
Check the Events calendar in the CHAT or on the CAS website (or contact the people listed above) to learn more about all these events. I hope I’ll see many of you at many of these October events!
Former CAS president Kris Hagglund suffered multiple injuries in a zipline accident in his backyard over Labor Day Weekend. He spent one night in the hospital and is recovering well under Lori’s care, now spending partial days at his office. We wish him a full recovery in time to enjoy a planned birding trip to Belize in February, 2019. Lori says that good wishes are most welcome, but they’re getting along fine at this point. – Thanks to Edge Wade and Lori Hagglund for this notice.
Official meeting minutes will be posted to the website after approval at each subsequent board meeting, meaning they are delayed from immediate publication. Minutes from the September board meeting were not available by publication time; please look for updated information in the October newsletter.
Carrying out our mission through education, conservation, and outreach takes a wide variety of resources, from the valued time of dedicated volunteers to the financial support of members and donors. We welcome and appreciate all participants and supporters of our work through their generous donations of time, money, or other resources.
The Chat is published online on the first of every month from September through May. Submissions are welcome, including photographs, stories, and suggestions for content; please contact News Editor Eric Reuter. The submission deadline is the evening of the 25th of each month.
– by Eric & Joanna Reuter
If you’ve taken a walk at the Columbia Audubon Nature Sanctuary this year, you may have noticed an abundance of pawpaw (Asimina triloba) trees in some locations. These like to grow in colonies, generally within an existing understory, meaning that once they get established they can crowd out other species. Although pawpaws are Missouri natives, they belong to a mostly tropical family (Annonaceae) and produce a distinct banana-like fruit that’s quite tasty when ripe. The trees appear tropical, too, with their large clusters of big, distinct leaves.
The modern presence of this “tropical” species in Missouri is interesting, as some researchers and writers have suggested that the mammals currently inhabiting our forests are ineffective at dispersing the seeds of some North America’s more unusual remnant tree species. This argument is based on the concept of evolutionary anachronism, essentially the idea that now-mostly-extinct mammalian mega-fauna (like mastodons) played an important role in seed dispersal for a variety of plants. In theory, plant mechanisms adapted to rely on such animals don’t really function anymore in the current ecosystem, reducing the plants’ viability and population distribution. This is a really fascinating concept, and there’s a pretty strong case for it with regards to some other North American species such as Osage orange. However, despite claims like this Georgia article’s that “no living North American animal can swallow pawpaw seeds whole”, Missouri Pawpaws are clearly a coveted food source for many mammals. The Missouri Department of Conservation’s pawpaw page states that “the fruit is relished by numerous bird species and by squirrels, opossums, and raccoons” and we’ve observed and photographed mammalian scat containing pawpaw seeds. Pawpaws may well represent a holdout from a very different climatological and ecological time in Missouri, and as such are worth taking a closer look at.
That being said, even native species can become problematic when over-abundant, as many Missouri land managers’ constant battles against Eastern Red Cedar attest. For example, a 2010 study showed that dense pawpaw stands can reduce other tree seedlings’ establishment by 1.5 to 3 times. One factor that can drive pawpaws to become dominant in the understory is heavy deer pressure, as deer selectively avoid pawpaw leaves while eating most other plants. Many visitors to CANS notice the tame and numerous urban deer that are certainly influencing the area’s ecosystem. A 2014 study in Illinois concluded that under such deer pressure,
“…the development of a dense paw paw understory canopy will further decrease species diversity and reduce tree species recruitment. Based on the life history traits of paw paw, and high deer densities and selective browsing, this issue is of concern for current and future forest communities.”
Another factor encouraging dense stands of pawpaws is the lack of fire in many modern forests, as suggested by a 2018 study in southeastern Missouri on various methods of controlling dense stands of pawpaw. Overall, it’s likely that dense pawpaw stands reflect an ecosystem disturbed by the lack (fire) and/or overabundance (deer) of other factors that might have maintained a different balance.
Given the dense stands of pawpaws in certain parts of CANS, questions regarding its management were recently raised at a CAS board meeting. After discussion and subsequent research, a consensus was reached that certain stands should become a target for removal or thinning, particularly those threatening to interfere with trails or viewsheds (such as a large, otherwise open oak tree becoming surrounded by pawpaws). However, most stands of pawpaws are distributed throughout the woods at CANS and are considered a lesser concern for now compared to more pressing projects. These can also be seen as representing a reasonably natural part of the ecosystem that provides food and shelter for a wide variety of animals. In the long term, establishing a fire regime and/or controlling deer would have the most impact on pawpaw density, and in the meantime it’s quite possible that dense pawpaws are also shading out and preventing the establishment of far less desirable invasives like Bush Honeysuckle.
If you take a walk at CANS this fall, one easy place to find dense pawpaws is along the forest trail between benches B and D (see map here). Earlier this year, these trees held abundant fruit, thought they’ve likely been eaten by the time this is read (we ate fully ripe fruits from our property in mid-September). The complicated questions surrounding pawpaw growth and management are a good reminder that birding is never just about the birds. Looking at the ecosystems that support our favorite birds is a good way to deepen our appreciation and understanding of the complex systems supporting all life, including the inevitable role of human influence and management (after all, we’re the ones who suppressed fire and encouraged deer!).
-Note: Thanks to Bill Mees for first raising this question and to John Besser for additional research.
Saturday, October 20th | 8:00 a.m.
Carpool departs from Moser's (4840 Rangeline St.) at 7:50 a.m.
Saturday, November 10th | 9 a.m. until noon
We’ll carpool from the AC Commuter Parking Lot at 8:20 a.m. The lot is on the southeast corner of the AC exit off Hwy 63 on Lenoir St.
Wednesday, January 16th, 2019 | 7:00-8:00 p.m.