This is the time when many students and faculty spend their days in the field doing research or attending conferences and meetings where they present their latest research results. Follow us on social media #ASCinthefield. We will not post here until the beginning of classes on August 22.
Have a great summer!
Tropical Behavioral Ecology and Evolution class at the entrance to the Smithsonian Tropical Research Institute canopy crane, Metropolitan Nature Park, Panama City, Panama. Photo credit: Ryan McCarthy.
For the Tropical Behavioral Ecology and Evolution course in Panama, we established independent research projects, networked with the internationally-renowned Smithsonian Institution, got to know Panamanian culture, and made new friends. In addition, we had the opportunity to see some very charismatic Panamanian creatures, including the three-toed sloth (Bradypus variegatus). Attracted by their soothing movements, mischievous smiles, and tendency to hug things, I have long desired to see one of these slow, long-armed teddy bears of the jungle.
The chance to see a sloth came during a visit to Metropolitan Nature Park, where our group was preparing to board a canopy crane. Suddenly, while waiting excitedly to be lifted into the tropical rainforest canopy, out rang the call of, “İPerezoso!” the Spanish word for sloth, which also means “lazy.” All attention was diverted to a nearby forest edge, where a baby three-toed sloth was descending vines and trees, moving toward the ground.
We learned from one of the crane operators that sloths go to the ground to poop, a risky endeavor that makes them vulnerable to predators. It is thought that movement to the ground may benefit the moth and algae associates that live on a sloth’s coat, which the sloth relies on for camouflage. Regardless of its biological function, our group capitalized on the little sloth’s potty break as a photo opportunity.
Adult sloth high in the canopy of an Anacardium excelsum tree. Photo credit: Ryan McCarthy.
When the crane was ready to take another group into the canopy, we begrudgingly pulled ourselves away from the baby sloth. Little did we know that we would see mama sloth, poised in the canopy and waiting for her little one’s return!
Our earth’s tropical rainforests are full of amazing biodiversity. The story of the sloth’s epic journey to the forest floor is just one of many biological sagas playing out in nature. You don’t have to go to the jungle to make amazing discoveries—check out a local natural area today!
About the Author: Kali Mattingly is a PhD student in Steve Hovick’s lab studying population ecology and genetics of invasive plants. Kali recently participated in the Tropical Behavioral Ecology and Evolution course in Panama under Dr. Rachelle M. M. Adams and Dr. Jonathan Shik.
You may have heard that researchers discovered a new species of flying squirrel. These squirrels had lived in plain sight for decades but only recently did Brian Arbogast and colleagues investigate the DNA of some of these animals. Their findings were revealing: The Pacific squirrels cluster separately from the northern and southern flying squirrel. The researchers analyzed mitochondrial DNA as well as microsatellite data to reveal this new evolutionary relationship.
Note: Mitochondrial DNA and microsatellites are parts of a species’ genome that are regularly used to construct evolutionary trees. In addition to the DNA in every cell’s nucleus in our body, mitochondria, the energy powerhouses in our cells, have their own genome. This mitochondrial genome is relatively small, is inherited from the mother only and has relatively high mutation rates. It is like a small clonal lineage within an organism which makes it ideal for evolutionary studies. Microsatellites are short sequence repeats in the nuclear genome that do not produce proteins. Thus they are free to mutate at a higher rate than coding sequences – mutations will not mess up protein production- and they frequently vary in length and thus reveal relationships among organisms.
A few weeks ago, before this study was published, 2 species of flying squirrels were considered to exist in North America, the northern and the southern flying squirrel. Here in Ohio the northern flying squirrels is resident – it is nocturnal though, that’s why you probably have not seen one yet.
Map showing distribution of now 3 species of flying squirrels
DNA analysis showed that the coastal squirrels in Washington and Oregon are distinct from their northerly relatives and that they actually only co-occur with them at 3 sites in the Pacific Northwest. Northern and the newly described Humboldt’s flying squirrel do not interbreed at these sites. By the way, the researchers named the new species Glaucomys oregonensis because the specimen that was used to describe the species was collected in Oregon.
You may recall from a previous post, that Dr. Andreas Chavez in our department of EEOB studies relationships among squirrels in a different genus, Tamiasciurus, the red squirrel T. hudsonicus and the Douglas squirrel T. douglasii. These two species share habitat in the Pacific Northwest and they do hybridize.
Dr. Chavez was not available for an interview for his thoughts on the new species description of flying squirrels, because he is currently pursuing his own fieldwork in the Pacific Northwest. He and his field assistant Stephanie Malinich are collecting data to better understand the hybrid zone dynamics between the Douglas and red squirrel.
We will give you an update on Dr. Chavez’ research once he returns.
About the Author: Angelika Nelson is the curator of the Borror Laboratory of Bioacoustics and writing this post for Stephanie Malinich, collection manager of the tetrapods collection. Stephanie is currently doing fieldwork on the red and the Douglas squirrel in the Pacific Northwest.
Another seabird species that I found to breed in Ireland is the Northern Fulmar Fulmarus glacialis. In a fleeting glimpse this bird may look like a gull but a closer look quickly reveals that is a close relative of albatrosses and shearwaters, the tubenoses Procellariiformes.
Can you see how this group of birds, the tubnoses, got its name? Doesn’t it look like they have a tube on top of their bill? This tubular nasal passage is used for olfaction. Yes, some birds do have the ability to smell. Especially seabirds use this sense to locate flocks of krill, shrimp-like animals that feed on single-celled marine plants (phytoplankton) right below the ocean’s surface. Breaking up phytoplankton cells releases a chemical called dimethylsulfide that concentrates in the air above areas where phytoplankton and thus krill are abundant. Researchers suspect that seabirds may smell their prey.
An acute sense of smell may also aid these birds to locate their nest within a breeding colony – you may recall the dense breeding conditions on the coastal cliffs from Monday’s post.
Furthermore, at the base of their bill these true seabirds have a gland that helps them excrete excess salt as they drink seawater. These birds and their relatives often spend long times out over the ocean without any land in sight. Thus they depend on drinking seawater.
So what do Northern Fulmars sound like? They are especially vocal when they return to their partner on the nest, they engage in an often minutes-lasting greeting ceremony. Listen to this pair recorded by Gabriel Leite in Clare county, Ireland (XC372370):
The unique morphological characteristics make these birds well adapted to their preferred environment of the northern oceans. They are among the longest-lived birds known, researchers estimate an average lifespan of 32 years for the Northern Fulmar.
About the Author: Angelika Nelson is the curator of the Borror Laboratory of Bioacoustics and currently teaches at the Audubon summer camp on Hog Island, ME.
Like every year I will leave for Hog Island, Maine tomorrow morning. I will teach at two of the Audubon summer camps that have been held on the island almost every summer since 1936. You may recall this from my previous post.
This year I am particularly excited to watch birds along the Atlantic coast as I just returned from a trip to Ireland, on the other side of the Atlantic ocean. There I spotted birds of several species that also occur along the US coast. I doubt that the birds themselves make the crossing, but members of their species reside and breed on both sides of the Atlantic.
Rathlin Island
So which birds are we talking about? In Europe we visited Rathlin island, a small island off the coast of Northern Ireland, where we watched Atlantic Puffins Fratercula arctica, Razorbills Alca torda and Common Murres Uria aalge – or Common Guillemot as they are referred to in the UK. The Royal Society for the Protection of Birds (RSPB) runs a seabird center along the cliffs of the island where volunteers and staff regularly survey the breeding colonies and answer visitors’ questions. The resident naturalist shared with us the latest numbers: they estimate 100,000 Common Murres to breed on the cliffs, with them 20,000 Razorbills and some 700 pairs of Atlantic Puffins, everyone’s favorite due to their colorful breeding plumage.
Atlantic Puffin on Eastern Egg Rock
On the US side of the Atlantic, in Maine, some 550 breeding pairs of these colorful seabirds have been reported in the largest colony on Seal island, ME.
Enjoy some photos of the Irish coastal scenery – I wish my photos conveyed the noise and smell that comes with large seabird colonies like these … David Attenborough in his Life of Birds series refers to these breeding conditions as the” slums in the bird world”.
Most of these seabirds are not known for their vocalizations (although Black Guillemots may be exceptional with their distinct whistle; you can hear some in the background of the puffin recording below). Here are some recordings that I found in our collection:
Doug Nelson recorded this Atlantic Puffin on Matinicus Rock, Knox county, Maine, USA on 3 June 1981 (BLB23883):
Lang Elliott recorded a Common Murre on water near the Gaspesie Provincial Park, Bonaventure Island, Quebec, Canada on 1 July 1989 (BLB17181):
Common Eider is another bird that breeds on both sides of the Atlantic. Hear some nestling calls recorded by Don Borror on Eastern Egg Rock, Muscongus Bay, Knox county, Maine, USA on 23 June 1958 (BLB3508):
As you can see, most of these recordings were made a long time ago; time to go back and get some more recent recordings!
About the Author: Angelika Nelson is the curator of the Borror Laboratory of Bioacoustics and team-teaches at the Audubon summer camp on Hog Island, ME.