Category — plant research
Numbering in the billions in 1800, the passenger pigeon was formerly one of the most abundant bird species on Earth. On September 1, 1914, Martha, the last known passenger pigeon, passed away at the Cincinnati Zoo after tireless efforts over several years to find her a mate.
To commemorate the 100th anniversary of Martha’s passing in 2014, the Zoo renovated its Passenger Pigeon Memorial, transforming it from a single-species memorial to an educational exhibit with a positive and hopeful conservation message that segues from the story of the passenger pigeon to modern wildlife conservation efforts.
A small crowd of Zoo visitors and staff along with media representatives gathered at 11:00 AM on September 1, 2014, as Zoo Director Thane Maynard dedicated the Memorial and officially reopened its newly restored doors. Watch the dedication video here.
Visitors to the Memorial are greeted by a large reproduction of John Ruthven’s 2013 painting of Martha, the Last Passenger Pigeon on the entry wall.
A display case on the back side of the entry wall contains a reprint of John J. Audubon’s Passenger Pigeon hand-colored engraving from The Birds of America, along with an actual net used to catch passenger pigeons, a platform stool to which blinded pigeons were tied as decoys, a cast model of a passenger pigeon and an Aldo Leopold quote.
Interpretively, the exhibition flows from left to right along the interior walls, circulating around an octagonal case in the center of the building containing passenger pigeon sculptures carved by Gary Denzler.
Signage was designed based on elements from Ruthven’s painting with pop-up panels featuring colorful images and text. The first wall tells the story of the passenger pigeon and its extinction, why it happened, and the scope of this loss.
Next, it describes how the passenger pigeon’s extinction was a wake-up call that spurred the conservation movement in America, highlighting the stories of native species that were nearly lost, such as white-tailed deer.
The last wall introduces conservation champions of the Zoo and presents examples of how we are working to save species today, including the Sumatran rhino and the American burying beetle, from going the way of the passenger pigeon.
The rehabilitation of this historic building and exhibit was made possible through the generosity of the H.B., E.W. and F.R. Luther Charitable Trust Foundation, Fifth Third Bank, and Narley L. Haley, Co-Trustees.
September 10, 2014 2 Comments
As we described in a previous post, several samples stored in the Frozen Garden of CREW’s CryoBioBank are going to be removed during the next months in order to examine their viability. And, here are results from the first ones: Coming to life after being stored for 15 and 20 years in the ultra-low temperatures of liquid nitrogen (-321 F!!)! And the most interesting result…they germinated as fast and as well as they did the day they were frozen!
These are seeds from poplar trees. Seeds from poplars, and also from most willows, germinate very fast because in their natural habitats they have enough water available when they are shed, but also because they must germinate in a short window of time. These trees grow very close to water courses and floodplains where there are frequent disturbances of the substrate in which they grow. The most common disturbance is flooding, which in most cases removes the soil and washes away the seeds and seedlings that are not established. Moreover, during winter, water in the soil can freeze, damaging any ungerminated seeds that remain completely wet along the river banks. For these reasons seeds are shed at the end of the spring and beginning of the summer, when temperatures are warm enough and water availability optimal. Thanks to their fast germination (within 24 hours!) poplars and willows can grow quickly in the summer days, establishing small trees that will be big and strong enough to survive flash flooding and the cold and dry winter. However these seeds are very short lived, and die at ambient conditions in just 2 or 3 weeks if they do not germinate. In the Frozen Garden of CREW at the Cincinnati Zoo and Botanical Garden we have preserved their initial viability and rate of germination for several years; including some samples stored up to 2 decades!! Thanks to these experiments we have demonstrated that seeds from endangered poplars and willows can be preserved for long periods of time, in order to keep them alive for our future generations!
Along with poplars and willows, orthodox seeds of several species were removed from liquid nitrogen in June. Orthodox seeds are those seeds that naturally dry during their maturation in the fruit, and thus they can be frozen in seed banks, keeping their initial viability and vigor. So, we could say that they have a “natural” predisposition to be stored at the low temperatures of liquid nitrogen. We have chosen these samples since they do not have special requirements for their recovery and germination, as other samples stored in the frozen garden have (as shoot tips, etc). Germination is the easiest way to analyze seed viability, and, at the same time, it produces seedlings that can be grown to produce plants for future use.
In order to recover seeds from the Frozen Garden, the cryovials with seeds were carefully removed, since dry seeds at very low temperatures are very brittle and we didn’t want to damage them. Then the cryovials were thawed at room temperature for 1 hour. Seeds were re-hydrated in a moist, saturated environment over night to avoid any imbibitional damage, which is damage that can be produced by rapid water uptake when seeds are very dry.
Some of the seeds have special requirements for germination because they are dormant. One of these special requirements is a “moist/cold stratification” for several weeks in order to break the dormancy and stimulate germination. It is as if the seeds were resting in the soil of winter! Seeds that did not require stratification were sown in petri dishes on blue filter paper particularly designed for seed germination. Then they were put in a controlled temperature and light growth chamber, and germination was monitored daily.
Seeds from several species have germinated very well after storage in ultra-low temperatures for several years, including the short lived seeds of the endangered plant, native to eastern North America, Plantago cordata (heartleaf plantain). The heartleaf plantain is threatened or endangered in 11 states including Ohio, Illinois and Kentucky because populations have declined or disappeared almost everywhere. The heartleaf plantain is a wetland plant with highly localized distribution which makes it very sensitive to habitat destruction, particularly that occurring for urbanization. We have stored their seeds for 14 years without any decline in their initial germination.
More samples will be removed soon! We will keep you updated with the most interesting findings!
September 9, 2013 2 Comments
In August, CREW staff traveled down to Daniel Boone National Forest in Kentucky to accompany the US Forest Service in their annual survey of our Cumberland sandwort experimental outplanting. The Cumberland sandwort is a small, delicate plant that clings precariously to the sandy soil of sandstone rock formations in the Cumberland Plateau of southern Kentucky and northern Tennessee. It is endangered, in large part due to trampling by hikers and people scavenging for Native American artifacts. CREW has been working with the US Fish & Wildlife Service to help preserve and protect this little plant.
Using seeds collected in 1994 from Pickett State Park in Tennessee, CREW established 10 genetic lines of the Cumberland sandwort in our tissue culture lab, and we banked each line in liquid nitrogen in our CryoBioBank. In 2005, to test whether the plants grown by tissue culture could be used to re-establish a population if needed, CREW and the US Forest Service planted 77 plants from our tissue culture lab in a sandstone cave in Daniel Boone National Forest that had a habitat similar to the native habitat of the sandwort. On our August 2013 trip to that experimental outplanting, we counted 160 plants!
It looks like our experimental outplanting is flourishing in its new location, so now we want to look at the genetic diversity of the outplanting. Genetic diversity in a population is important because it allows the population to adapt to changing environments, or to survive and develop resistance to disease. Although we had started with 77 plants, they were all clones of the 10 original genetic lines established in our tissue culture lab. On our trip, we collected leaf samples from 35 individuals to analyze using microsatellite markers. For comparison, we also traveled down to the two locations in Pickett State Park that our original seeds were collected from and collected about 150 total leaf samples from the two large populations. Now we’re working on extracting DNA from the nearly 200 leaf samples collected this August. We should be able to compare the amount of genetic diversity generated in the experimental outplanting with the amount of genetic diversity naturally found in the original populations. This study is part of a larger study where we are evaluating the genetic stability of tissues that have been stored in liquid nitrogen for up to 20 years – a project that is supported in part by a grant from the Institute of Museum and Library Services, as well as CREW’s Eisenberg Fellowship. It should give us insight into how to manage and protect threatened and endangered plant populations more effectively. Keep an eye out for our results!
September 3, 2013 No Comments