Saturday, September 28th, twenty-two of us attended the Docent Recognition luncheon this year. It was catered by Bad Brad’s Barbeque, which was good. Even though it rained, Harvey Payne led a short walk to the Mathews Cabin. This year we have audio of the proceedings recorded in living stereo and saved in .mp3 format. This HiFi recording is 20 Mbytes in size and will take a long time to download across a slow connection: Docent-Luncheon-20130928-Hi.mp3. This LoFi recording is 5 Mbytes in size and should be quicker to download: Docent-Luncheon-20130928-Lo.mp3. Your browser should be able to play the files using the media plug-in; try it, otherwise you will need to download the file and then open it with your media player.
The research station has new artwork by Jason Stone entitled A Time of Peace
that
was donated and shown above.
The American Robin is truly a North American bird. I have seen this bird from the Atlantic to the Pacific shores. While sitting on the porch at Sagamore Hill in the early morning, I have seen the Robin foraging on T.R.’s front lawn. I was surprised to see the American Robin combing the banks of the Yellowstone River for black flies and equally surprised to flush a Robin from dried kelp on the rocky beaches of the Straits of Juan de Fugo on Vancouver Island, but nothing should surprise you about this versatile bird. It is a year round resident of the continental United States and southern Canada from Newfoundland to British Columbia. During the summer the Robin migrates as far north as northernmost Canada and Alaska and in the winter some Robins travel as far as southern Mexico and Guatemala. As you can see the Robin has an extensive range and a population of some 320 million individuals to fill this vast space.
Prior to the European colonization of North America, the Robin had a place
in Native American folk lore. A number of different native tribes tell
tales of how the Robin got its red breast by fanning the dying embers of a
camp fire to save a lost man and his son from freezing. The Tlingit people
tell how the Robin is a gift from Raven to please people with its song, if
you listen to a Robin’s song it sounds like cheerily, cheer up, cheer up,
cheerily, cheer up.
The males begin to sing during the dismal days of
late winter and early spring and their song is a promise of warmer days to
come.
The name Robin for this species has been recorded since at least 1703. It appears that homesick European colonists named this bird for their European Robin which is smaller and less colorful.
The European Robin is a member of the flycatcher family and is not a
thrush, although it does have a partially red breast. But the European
Robin pales in comparison to our American Robin, which is the largest
member of the North American Thrush Family. That compulsive lister, Carl
Linnaeus first described this bird in 1766; Turdus is Thrush and
migratoriusis from migrare to go
. Therefore the Latin name translated is
Thrush to go which is an apt description of this bird’s behavior. A 2007
DNA study of 60 of 65 Turdus species places the Rufous-collored Robin ( T.
rufitorgues) of Central America as the American Robins closest relative.
This relationship seems to suggest that the American Robin has only
recently colonized North America possibly since the end of the last ice
age.
Based upon early European accounts it appears that the American Robin was only lightly distributed across the continent. Robins had a preference for woodlands near open meadows. As the Europeans cleared the Eastern forest they opened up the land providing more habitat for Robins. As the settlers moved onto the treeless prairies they planted trees and suppressed fire, which again increased habitat for the Robin. Today the American Robin can be found in woodlands, gardens, orchards, lawns and fields. They prefer areas of open ground or short grass for foraging, with woodland or scattered trees or shrubs for nesting and roosting nearby.
Robins have a routine governed by the sun. At first light through the morning they forage for insects and worms on the open ground. They ingest more earthworms in the morning. Robins have a deliberate foraging technique when searching for earthworms. They run several steps, cock their head to the side and usually nab an earthworm.
The Robin hunts visually and also has the ability to hunt by hearing. They
particularly like freshly turned earth in gardens where worms and grubs
are abundant targets. As morning melts into early afternoon the Robins
move into the trees to feed on fruit and insects. In the winter they are
particularly fond of the fruit found on the Hackberry tree. I have seen
entire flocks descending upon the poor tree and stripping the fruit. 40-percent
of the Robin’s diet is earthworms, beetle grubs, caterpillars and
grasshoppers. 60-percent is wild and cultivated fruits and berries. As you sit on
the gift shop porch at the Tallgrass Prairie you can see this change take
place. Morning finds the Robins on the headquarters front lawn but as
morning morphs into afternoon the Robins move into the trees. Remember the
adage, the early bird gets the worm
, this describes the Robin’s behavior
in a nutshell.
People don’t get very excited about seeing a Robin because they are so common, but if you invest some time in observing them they will capture your interest. I can remember being shown my first Robin by my mother. It had built a nest in a large Cherry tree outside my second story bedroom window. The nest was visible and I spent many hours watching the adults brood the four pale blue eggs. I was intrigued at how busy the adults were after the eggs hatched, tirelessly caring for those young hatchlings. I was also astonished at how fast they grew from naked hatchlings to fully feathered juveniles. Then one day the nest was empty, I came to realize eventually we all leave the nest.
The American Robin can be described as a distinguished bird, with its gray brown back and wings, warm orange red breast and white throat streaked with black. The white crescents above and below their eyes are striking and when they are excited the feathers on the top of their heads lift displaying a small crest.
Nobody can mistake the identification of this bird. Males typically have dark heads while females are slightly paler. Juveniles have the same color pattern as females but have dark spots on their breasts as depicted by Douglas Pratt in the illustration at right.
Robins are the first birds to nest in the spring. This gives them an edge and they consistently successfully rear three broods during the breeding season. If you know where they are nesting and look carefully after the eggs hatch it is easy to spot the remnants of their Easter egg blue shells on the ground. Robins are monogamous during the breeding season. The female builds the cup shaped nest by herself with coarse grass, twigs, paper and feathers all woven together. She lines the interior with mud, spreading it with her breast after which she adds fine grass or other soft materials to cushion the eggs. The nest can be located from five to fifteen feet in a tree or shrub or the eave of a house or shed. A new nest is built for each brood. After a fourteen day period the three to five pale blue eggs hatch. They will fledge within two weeks of hatching. At this stage they are not strong flyers, they will hide in the brush and the adult birds will care for them. People finding these newly fledged birds think they have fallen out of the nest and usually pick them up and care for them, often with disastrous results. If you find a Robin fledging leave it alone the parents are often nearby and are caring for it. At the end of that two week period the fledglings are capable of sustained flight. The time period from fledging to sustained flight is the young bird’s most vulnerable time. Only one quarter of all young American Robins will live through the summer they are born in. Most Robins in the wild will only live two years. Although one tagged Robin did manage to live to the ripe old age of thirteen years, eleven months.
In the spring the Robin becomes anti-social as it seeks to establish and defend breeding territories. It is not uncommon for chance encounters to results in aerial pursuit and fights with other males over territory. You can often hear their loud whinny as they chase each other. Some battles can be intense and end in injury. However for most of the year the Robin is a social bird, especially during the winter. During this time you can often see them moving across the landscape in large numbers pushed before cold fronts. They are often here one day and gone the next. They also gather in large flocks at night to roost in trees. They make a racket calling to each other in the roost. The roosting flock will break up into smaller groups to feed. When feeding each individual Robin relies on his neighbor to see any sign of danger thus proving that multiple eyes are better than one to stay safe. The Robin needs all the help it can get in its efforts to stay alive. It leads a perilous life, as a juvenile it is preyed upon by squirrels, snakes, cats and some birds such as Blue Jays, Common Grackles, American Crows and Common Ravens. Things don’t improve with age because the adults are taken by a variety of hawks, cats and snakes. As you can see the vast numbers of Robins make it important as a prey item for predators. However, they are not defenseless; their social behavior helps them fend off small predators. Several birds will mob Blue Jays, snakes and even cats and hawks.
Aside from the interesting aspects of their behavior Robins are a mixed blessing to farmers. They help to control insect pests but because of their fondness for berries they do present a problem for berry growers. However farmers also affect Robins through use of pesticides, which can result in dead Robins as they ingest contaminated insects. Farmers and Robins have a complex relationship, in fact it was the early colonial farmers who increased the earthworm population when they imported plants in root balls containing European earthworms and who can forget the Japanese beetle and those fat white grubs.
The American Robin is a successful adapter, it is not a flashy bird but it is steady and dependable. If you take the time to watch it, you will be entertained by its antics throughout the year.
Look at this Bison bull. He is definitely in charge of his environment. He
stalks about the prairie and eats tons of grass, but from a particular
plant species’ point of view, he is just a transport worker. Look closely
at his face. It is covered with Tick-Trefoil or stick-tights or beggar’s
lice seeds. Tick Trefoil, Desmodium Illinoense Gray and five other
Desmodium species that occur in the Tallgrass Prairie Preserve, is a
legume with a bean-type of fruit. The fruit is technically a loment
,
which is a bean that breaks apart so that each seed is separate. But more
importantly, the fruit is covered with barbed hairs that will cling to any
animal that passes by. This adaptation allows the plant to be transported
from the parent plant and grow in a suitable habitat somewhere else, thus
increasing the range of the plant.
There are about as many seed dispersal mechanisms as there are plant species. We just explored one mechanism, and you can probably think of a dozen other species that use a similar mechanism—a cocklebur for example. Let’s look at some other mechanisms…
Look at the Green Milkweed pod in the picture above. It is full of seeds,
and it is best for the species survival for the seeds to be scattered. How
does the Green Milkweed accomplish this goal? Look inside the pod and you
will find hundreds of seeds. Each seed is a small hard dark speck that has
long hairs
attached to it. These pods split open naturally as the
season progresses, and the seeds are exposed to the elements of the
weather. The wind catches the hairs
and carries the seeds away.
Some of the seeds will land in a suitable habitat and grow. Again, you can
think of many other plants that use the wind for seed dispersal:
cottonwood, many grasses such as Little Bluestem, Maples.
Look at these Coralberry berries
. Technically, they are not berries;
they are drupes, like cherries, with a single seed within a fleshy
covering. Both parts are important in the plant’s seed dispersal plan. The
fleshy covering is a attractive food source for birds and mammals. I
prefer to remove the seeds from cherries before I eat them, but birds and
mammals that eat the Coralberries do not necessarily do so. The seeds,
which have an indigestible seed coat, will pass on through the bird or
mammal’s system unharmed, and will be deposited somewhere else.
Coralberries are an important food source for a large number of birds and
mammals such as deer. The system is obviously working, because
Coralberries are found throughout the wooded areas of the Preserve. I
suspect you can think of any number of plants that use animals to
transport their seeds by providing an enticing food that contains the
seeds.
Seed dispersal is critical, and plants have evolved specific mechanisms to
accomplish it. They can use physical aspects of nature such as weather,
moving water, and gravity, but they have also developed mutual, or
one-way, relationships with animals and even humans to help them. When I
say develop
, I am not implying planning and thinking, but develop
through the process of selection for the genetic variants that make the
species better at surviving. Isn’t it great that we have the Tallgrass
Prairie Preserve where activities such as seed dispersal can proceed and
keep the prairie functioning naturally?
Since I am covering the counts for three months, it was easier to do using tables. I hope this method will be easy to read and make comparisons. Paraguay was the only new country added since the last count, and the visitors from there came in June. The table to the right displays total counts for January through August, 2013, with those months in previous years.
I encourage each of you make sure to ask our visitors to sign the guest book. During reorientation, we talked about temporarily moving the book to the counter while the Center is open, which gives better opportunity to encourage visitors to let us know from whence they come; just remember to return it to the hutch when you close. I think you’ve been doing a good job. Just keep it up. Here’s to a high visitor count in 2013 and a great year for the prairie!
Here we provide some links to other places worth visiting.
Here is the latitude and longitude of the Visitor’s Center that you can give to visitors for entry into their GPS navigation device.
The manufacturer’s instructions for cleaning the touch-screen recommend use of a soft dry cloth only. This proved inadequate for smeared fingerprints. Soft-paper kitchen towels work well, slightly damp with a small drop of soft handsoap. Application of a dry kichen towel removes any residual moisture.
Over time, a matter of several weeks continuous operation, I have noticed that calibration of the touch-screen drifts away from the initial set-point. If you notice that the cursor isn’t under your finger when you touch the screen then restart the kiosk by unplugging it from the wall, waiting a few moments and then re-inserting the power plug. It will restart and recalibrate.
This link points to the complete Kiosk Maintenance Manual.
Some printed back issues of the Docent Newsletter, to February 2009, can be found in the two green and one blue-black zip-binders, stored in the Perspex rack by the file cabinet in the office of the Visitor’s Center.
All back issues are available electronically via the links shown below. All newsletters prior to December 2007 are available in Portable Document Format (PDF), which means that you will need Adobe Reader installed on your computer to read these files. All newsletters from December 2007 onwards are in HTML format that is easily read using your web-browser.
2013—January
February
March
April
May
June
July
August
September
October
November
December—2013
2012—January
February
March
April
May
June
July
August
September
October
November
December—2012
2011—January
February
March
April
May
June
July
August
September
October
November
December—2011
2010—January
February
March
April
May
June
July
August
September
October
November
December—2010
2009—January
February
March
April
May
June
July
August
September
October
November
December—2009
2008—January
February
March
April
May
June
July
August
September
October
November
December—2008
2007—January
February
March
April
May
June
July
August
September
October
November
December—2007
2006—January
February
March
April
May
June
July
August
September
October
November
December—2006
2005—January
February
March
April
May
June
July
August
September
October
November
December—2005
2004—January
February
March
April
May
June
July
August
September
October
November
December—2004
2003—January
February
March
April
May
June
July
August
September
October
November
December—2003
2002—January
February
March
April
May
June
July
August
September
October
November
December—2002
2001—January
February
March
April
May
June
July
August
September
October
November
December—2001
2000—January
February
March
April
May
June
July
August
September
October
November
December—2000
1999—January
February
March
April
May
June
July
August
September
October
November
December—1999
1998—January
February
March
April
May
June
July
August
September
October
November
December—1998
1997—January
February
March
April
May
June
July
August
September
October
November
December—1997
1996—January
February
March
April
May
June
July
August
September
October
November
December—1996
1995—January
February
March
April
May
June
July
August
September
October
November
December—1995
This persistent index of selected topics should make finding articles of interest easier. The list will grow as I move further into the past and it will grow as I add interesting topics from each new newsletter. Iris McPherson lent me the paper copies of the newsletter from the very early years of the docent program; I ran them through a scanner equipped with a document feeder, saving them as PDF files, then added them to Back Issues section above. Let me know of any dead links that you discover. Also, please lend me any paper copies of the newsletter that are missing so that I can scan and add them to the list of back issues.
Deadline for submission of articles for inclusion in the newsletter is the 10th of each month. Publication date is on the 15th. All docents, Nature Conservancy staff, university scientists, philosophers, and historians are welcome to submit articles and pictures about the various preserves in Oklahoma, but of course the Tallgrass Prairie Preserve in particular.