Scientists from the Academy focus on critical global issues in biodiversity, evolution, and environmental science. Our research efforts enable us to provide accurate, real-time scientific information to the public on environmental and sustainability matters. The Academy’s scientific collections contain more than 18 million scientific specimens that our explorers have collected throughout the world. This library of life on Earth preserves a long-term record of environmental change and is a rich source of information for scientists studying climate change.
With this information at our fingertips, the Academy is contributing a unique and crucial voice to the ongoing conversation on climate change. The photographs and captions below address climate change’s impacts through the lens of Academy research.
Black-capped and Carolina Chickadees
The Academy’s Ornithology Collection is helping scientists demonstrate the effects of climate change on black-capped and Carolina chickadees, two similar yet genetically distinct species with respective ranges in the northern and southern United States. The species merge within a central hybrid zone where they produce genetically mixed offspring. Using geographic data and chickadee tissue samples preserved by former Academy Curator Frank Gill in the 70s and 80s, Cornell ornithologists confirmed that the hybrid zone moved seven miles north between 2002 and 2012. This northward shift has occurred as the minimum average winter temperature has increased, suggesting that the hybrids require a certain average low temperature for survival and are moving north to stay within that temperature range as the climate warms. Robert Driver, former Academy ornithology curatorial assistant who is studying these populations as a graduate student at Villanova University, says that hybridized chickadees are less likely to hatch successfully compared with genetically homogeneous populations. Photo by Mike Servedio/ANS
Monarch Butterflies
The number of monarch butterflies migrating to their overwintering grounds in Mexico each year is declining, and scientists are investigating links to climate change. Along with deforestation in Mexico and agricultural disruption of the milkweed flora in the U.S. where the butterflies lay their eggs, extreme weather and dramatic temperature changes may be affecting the timing of monarchs’ annual migration. Photo of monarchs from the Academy’s Entomology Collection by Mike Servedio/ANS
Crane Flies
Academy Entomology Curator and crane fly expert Jon Gelhaus has been identifying crane flies on his property in Camden County, New Jersey, for more than 20 years. Only in the past few years has he recorded the crane fly species Tipula mariannae, known previously only from Florida and therefore a surprising new record for New Jersey. Gelhaus says this could be evidence of the species expanding its range north along the Coastal Plain. “Is it due to climate warming? I don’t know, but it is intriguing,” says Gelhaus. Only a handful of scientists specialize in crane flies, so he may be among the first to ask these important questions. Photo by Mike Servedio/ANS
Changes in Mongolia
In the past 70 years, Mongolia’s average annual temperature has risen almost 4 degrees Fahrenheit. Weather patterns have changed drastically as a result of Arctic amplification, a phenomenon in which global warming spurs temperatures in and around the Arctic to rise at a faster rate than they do in the rest of the world. Formerly silky, calm rains have become short yet intense downpours that quickly run off, fail to moisten the ground, and upset the migrations of the herders who depend upon the land for survival. The short grass and bare earth in this photograph reveal the effects of overgrazing and climate change, both of which are becoming widespread in Mongolia. Photo by Stephen Mason/ANS
Sea-level Rise
When global temperatures increase, oceans warm and ice melts, causing seawater to expand and flood into coastal areas. Here, Academy wetland ecologist Elizabeth Watson stands in front of the remains of Atlantic white cedar trees in Dividing Creek, New Jersey. Like many other trees in coastal forests, these trees are not salt tolerant. They died as a result of sea-level rise, leaving space for salt marshes to creep inland. Photo by Kirk Raper/ANS
Photographs and captions originally appeared in the Winter 2016 issue of Academy Frontiers. Compiled and written by Mary Alice Hartsock.
Since Philadelphia has had both Northern and Carolina Chickadees in the past, does your research mean that we now only have Carolina Chickadees in Philadelphia? If not, where do you think the border is between pure Carolina Chickadees, mixtures, and pure Northern Chickadees within Philadelphia?
Linda, here are some answers to your questions from expert Robert Driver:
Q: “Since Philadelphia has had both Northern and Carolina Chickadees in the past, does your research mean that we now only have Carolina Chickadees in Philadelphia?”
RD: Yes. We only have Carolina Chickadees in Philadelphia now. However, during eruption years (low food sources in the north for Black-capped Chickadees) Black-capped Chickadees come further south in the winter and both can be found in Philadelphia during these times.
Q: “If not, where do you think the border is between pure Carolina Chickadees, mixtures, and pure Northern Chickadees within Philadelphia?”
RD: The current border is not in Philadelphia- but has moved north. It is currently located in the Lehigh Valley. If you scroll down to page 3 of the following .pdf file, you can see a map depicting the borders.
http://www98.homepage.villanova.edu/robert.curry/Documents/RLCpubs/Taylor.2014.pdf