At 6:01 pm President Barbara Saunders called the meeting of the Society to order. Vice-President Lydia Thomas then introduced Linnaean Society Council Member Ken Chaya, artist, graphic designer, travel writer and “compleat” naturalist. Ken is the creator of the map of all the trees of Central Park, “Central Park Entire.” In his talk entitled “Wild Green Heart” he described the origins of the map, the impetus for which came from Edward “Ned” Sibley Barnard. Its creation involved the plotting of all the trees in individual small areas bounded by paths and roads, and the addition of graphics showing rocky outcrops and architectural features. On showing the completion of the Ramble section to Ned, he suggested that the map be extended to the whole park, a mammoth undertaking. Ken acknowledged Ned and Neil Calvanese of the Central Park Conservancy as being extremely helpful in teaching him how to identify trees, which heretofore he had regarded simply as sites for birds to land and to nest. The initial version of the map was completed in 2010 and included approximately 20,000 individual trees. The map is now available as an app, and each tree is clickable for more information. Ken went on to point out that several species were unexpected, such as a European spindle tree, a winged elm and a pumpkin ash, both southern species, and a balsam fir at the south end of the Park for which no records existed in the Conservancy archives. He speculated that it had been planted after Christmas by persons unknown. Ken also said that the population of trees is continually changing owing to weather conditions and removal by the Conservancy and that following one storm an oak was found to be over 200 years old, i.e. it predated the origins of the Park itself. In collaboration with Regina Alvarez of the Conservancy and Daniel Atha of the New York Botanical Garden, Ken also has been cataloguing the flowering plants in the Park. So far they have identified 428 wild species, among which they were disturbed to find a stand of Johnson grass near the Delacorte Theater. This is a very destructive invasive species and the stand had to be extirpated by the Conservancy. Ken then went on to show his photographs of several iconic bird species in the Park, among the more than 280 species that have been recorded. Turning to insects, Ken stated that although the total number of species is unknown, 17 of the 27 or 28 orders of insects found in North America have been recorded in the Park. He finished his talk by urging the audience to explore the Park and view it as a vibrant and dynamic urban ecosystem.
At 7:30 pm President Barbara Saunders reconvened the meeting to deal first with Society business. Recording Secretary Hamish Young read the minutes of the April 10th, 2018 meeting, and they were approved as read, with a correction sent later via an e-mail from Past President Rubenfeld. Secretary Anders Peltomaa announced one new candidate for membership, Mike Freeman sponsored by Ken Chaya. The nomination was approved unanimously by the membership.President Saunders reminded the members about the Great Gull Island Birdathon, scheduled for the weekend of May 12th-13th, upcoming field trips, and the regular Central Park bird walk, led by Richard Lieberman. She also stated that Society buttons, patches and field cards were available at the front of the auditorium. President Saunders also asked the audience for any field notes, and Council Member Gabriel Willow mentioned that recently he had seen a glossy ibis flying across Central Park from east to west.
After the business section of the meeting was concluded, President Saunders introduced Dr. Peter P. Marra, of the Migratory Bird Center of the Smithsonian Conservation Biology Institute. His talk, entitled “Studying Birds in the Context of the Annual Cycle: Carry-over Effects and Seasonal Interactions,” emphasized the necessity of studying bird populations throughout the annual cycle. Although all biological phenomena are profoundly affected by such cycles, until recently most studies of migratory birds had concentrated on one small part of the cycle, namely the breeding season. This arose not only from the academic calendar, when summers are free to perform fieldwork, but also from the difficult economics and logistics of studying birds throughout the cycle. New technologies have alleviated this somewhat, and he illustrated this by summarizing recent studies on Pacific loons. Embedded tracking devices have shown that those that breed on the North Slope of Alaska spend winter in the Far East, while those that breed on the west and south coasts travel to southern California and northern Mexico. This unexpected result suggests that the two groups may be genetically separate and warrants further analysis. The remainder of Dr. Marra’s talk concerned studies on American Redstarts. The study site in Jamaica consists of two contrasting environments, one a mangrove swamp that is wet throughout the winter and supports an abundant insect population and a secondary growth scrub that gradually dries out as the winter progresses. Birds from the latter area gain less weight, depart for the breeding grounds later, suffer a higher mortality and have significantly lower breeding success. This shows that conditions in the non-breeding period have profound effects on breeding success. Dr. Marra’s group also has analyzed the deuterium content of redstart feathers collected over many years. Because deuterium deposition is strictly correlated with latitude, the observed changes in deposition show that the overall breeding range has moved south over the past few decades. This correlates with a long-term drying trend in the Caribbean, a consequence of climate change, and suggests that deteriorating winter conditions may lead to later departures, and more southerly locations for the breeding grounds. Dr. Marra ended his talk by pointing out that for conservation efforts to be successful, it is necessary to understand the complete annual cycle and the effects of different environments and climatic conditions on the population dynamics of each species.
The meeting was adjourned at 8:47 pm.
Respectfully submitted by
Hamish Young, Recording Secretary