(Note: This meeting and presentation took place online, via Zoom platform technology, due to social-distancing protocols prompted by the ongoing COVID-19 pandemic.)
At 7:00 pm, President Ken Chaya called the meeting of the Society to order. After introducing himself and thanking the attendees for joining the meeting, he announced that there were currently 87 people in the meeting and that more were joining as he spoke.
Commencing with the business portion of the meeting, President Chaya announced the result of an online vote to approve the minutes of the January members’ meeting: it passed with 156 votes of approval, none of disapproval, and one abstention.
He then announced the result of an online vote to approve new members. It passed with 155 votes of approval, none of disapproval, and two abstentions. President Chaya welcomed the following four individuals as new members:
- Joel Golumbek, sponsored by Judy Rabi
- Matthew Fischer, sponsored by Debbie Mullins
- Deborah Shapiro, sponsored by Susan Axelrod
- Diane Schenker, sponsored by Sylvia Alexander
President Chaya then invited non-members in attendance to join the Society, explaining that they could learn how to do so by visiting the LSNY website, www.linnaeannewyork.org. He also pointed out that he or any of the other LSNY officers listed on the website would be willing to sponsor anyone who would like to join, emphasizing that an organization is only as healthy as its growing and diverse membership. He declared that the LSNY welcomes all to become members regardless of race, religion, gender identity, sexual orientation, age, background, ability, or geographic location.
As the final item of business, President Chaya announced that because of the ongoing spread of COVID-19, the organization’s 144th annual meeting will take place online rather than in person. The meeting is scheduled for 7:00 pm on Tuesday, March 8. The featured speaker will be Dr. Jennifer Duberstein. A formal invitation will be sent to all members by email or post, shortly.
He also reminded members that on March 8, voting for a new slate of officers and board directors will take place electronically immediately following the meeting. Members will need to watch for an email to arrive at the conclusion of the meeting and then cast their votes within 24 hours.
Finally, he referenced his February 3 president’s letter in which all members were invited to submit nominations from the floor for three open positions on the board. The letter also announced that, in accordance with the Society’s bylaws, a three-person nominating committee had been formed to submit nominations for these positions, as well. All nominations from the floor must be submitted to the Society’s secretary by midnight, February 21.
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At 7:09 pm, President Chaya introduced the evening’s speaker, John Marzluff, Ph.D., who presented “Rendezvous with the Raven: Exploring Connections Among the Trickster, Wolves, and People,” on his work studying ravens in Yellowstone National Park.
John Marzluff is James W. Ridgeway Professor of Wildlife Science at the University of Washington. His graduate research (Northern Arizona University) and initial post-doctoral research (University of Vermont) focused on the social behavior and ecology of jays and ravens. He continues this work, investigating the intriguing behavior of crows, ravens, and jays, and currently focuses on the interactions of ravens and wolves in Yellowstone. He teaches courses in ornithology, governance, and conservation of rare species, field research in Yellowstone, and the natural and cultural history of Costa Rica.
Professor Marzluff has written six books and edited several others. Welcome to Subirdia (2014, Yale), shows that moderately settled lands host a splendid array of biological diversity and suggests ways in which people can steward these riches to benefit birds and themselves. His most recent book, In Search of Meadowlarks (2020, Yale), connects our agriculture and diets to the conservation of birds and other wildlife.
He has mentored more than 40 graduate students and authored over 140 scientific papers on various aspects of bird behavior and wildlife management. He is a member of the U.S. Fish and Wildlife Service’s recovery team for the critically endangered Mariana Crow; a former member of the Washington Biodiversity Council; a Fellow of the American Ornithologist’s Union; and a National Geographic Explorer.
Dr. Marzluff began his presentation by stating that ravens are one of the most adaptable species on Earth and one of the most successful species of birds. He shared a graph indicating how raven populations have grown in just the past 40 years, as these birds have learned to adapt and take advantage of what humans have done to the land. They have not only made use of the human-modified ecosystem, but have influenced human cultures through their impact on religions and legends around the world. There has been a long-standing pattern of coevolution between people and ravens.
He then said that he would speak a bit about the biology of ravens, discuss their exploitation of people and wolves in the greater Yellowstone ecosystem, and address concerns about ravens’ effects on the species they prey upon.
He spoke about raven evolution, saying that the species had moved back and forth between the Old and New Worlds. The common ancestor of all ravens emerged in Africa about four million years ago. Ravens first came to the New World from Europe and Asia about two million years ago and were isolated here, where they continued to evolve independently. Other raven species were isolated in other parts of the world and evolved into separate species as well. A second invasion by Old World ravens of the New World took place about 15 thousand years ago. We can detect descendants from both invasions of the New World by their unique genetic sequences. Ravens of both types have thrived here, and they frequently and successfully interbreed.
Ravens form long-term pair bonds, often mating for life. However, in addition to a core social organization of paired birds, there are also non-paired individuals, which he referred to as “vagrant non-breeders.” Breeders and older birds have more status and are more dominant than younger and non-breeding birds, but the causes of the transition from non-breeder to breeder are still being studied.
Paired birds and vagrant non-breeders come together when exploiting rare foods, such as a large dead animal. Professor Marzluff said that if a pair discovers such food, they will eat quietly in an attempt to keep it for themselves. If they are approached by a non-breeding raven, they will attempt to fend it off, and the vagrant will make noise that attracts other ravens. Once a threshold of nine birds is reached, the territorial birds stop fighting and share the food, as it’s not worth it to continue the fight.
He said that in Yellowstone this feeding rivalry may be a bit different because of the presence of carnivores that make and consume kills very quickly. Another difference in Yellowstone is that the birds have access to anthropogenic resources such as dumpsters and wastewater treatment plants. They also can and do beg from tourists.
How do these things play into the lifestyle of ravens in Yellowstone? To find out, Dr. Marzluff and his collaborators began catching and eventually tagging over 70 ravens in Yellowstone with GPS transmitters.
One of the first things they found is that ravens are generalists that exploit many different food types. This wasn’t surprising, but they found the seasonality of ravens’ diets to be interesting.
For example, in the spring and fall, they exploit gut piles left by hunters; in the summer and winter they’re eating mostly invertebrates that are dispersed throughout the grasslands and upper elevations. They’re also spending time at waste-treatment facilities and eating roadkill and agricultural products.
Breeding ravens are constrained as to where they can feed during May through August, as they need to bring food back to their nests. Once breeding season is over, their travel for food can expand ten-fold from September through April—from 5.6 miles to 57 miles! They do this to take advantage of human subsidies (offal, wastewater treatment plants, etc.) once they no longer have to care for their young.
Their nestlings and juveniles tend to wander widely and settle on anthropogenic resources after fledging. Older non-breeders also travel extensively. He discussed movements of one older, non-breeding individual that was relying on anthropogenic resources prior to the park’s closure for three months because of the COVID-19 outbreak. When the park closed and human-based sources of food were not reliable, this bird wandered much farther. Over the course of the year, it covered about 6,500 square miles within a perimeter of about 525 miles.
Dr. Marzluff then discussed the strategies of individual ravens within both the vagrant and pair groupings. Taking advantage of the wolves that were reintroduced to the park in recent years, ravens will associate with them as part of a kleptoparasitic foraging strategy. Scientists studying these wolves found that over 86% of the times that wolves were spotted, ravens were seen with them. In contrast, ravens were seen with coyotes only about 3% of the time. Interestingly, 43% of 204 wolf kills found in the park by scientists were visited by ravens tagged by Dr. Marzluff and his team. Some of the kills were visited by up to a dozen tagged birds. However, 30% of tagged birds were never observed at a wolf kill, whereas 22% were regular visitors.
He then showed several maps and graphs demonstrating the build-up of birds at kills over several days, comparing tagged non-breeders with breeders. Some roosting birds came to nearby kills, but others did not—whereas some non-breeders flew great distances straight to recent kills.
He posited that non-breeding birds may travel great distances to these kills for social purposes as much as for food. At kill sites where multiple ravens are present, they have an opportunity to posture and assess their place in the dominance hierarchy or possibly find a mate.
The benefit to ravens of associating with wolves is evident, but what benefit does this association have for wolves? Dr. Marzluff showed GPS tracking results from 36 instances of wolves at raven aggregations. In 19 instances, a wolf arrived at a kill before or simultaneously with ravens, and in 17 instances, ravens arrived before a wolf. This may be evidence that in some instances wolves were drawn to kill sites by ravens. Even if that is the case, these data indicate that there is a six-fold greater benefit to ravens than to wolves—so there is a parasitic relationship between the two species.
In contrast to wolves, cougars have a much more one-sided relationship with ravens. In the seven instances where cougars were present at a raven aggregation, the ravens always arrived after the cougars.
Looking beyond ravens’ relationships with carnivores, Dr. Marzluff circled back to how humans are a prime food source for ravens. Ravens frequently beg and steal from humans, even going so far as to tear open storage bags on snowmobiles to obtain food. Our two species have adapted to and coevolved with one another. For example, ravens have learned how to open human-made containers, and humans have redesigned snowmobiles to be more raven-proof.
He concluded his talk by re-showing a graph indicating rising raven numbers in the West since the 1980s. These larger raven populations can be problematic for the endangered species upon which they prey, such as Snowy Plover, Greater Sage-grouse, and Desert Tortoise. Since 1995, the U.S. Department of Agriculture’s Wildlife Services has dealt with this problem by killing thousands of ravens annually. He said this approach is neither effectual nor justified, as we’re not taking any measures to halt or control the human subsidies that are fueling the increase in raven populations.
Controlling food subsidies around places of conservation concern has proven to be effective in reducing corvid use of those areas. He recommended methods such as incentivizing hunters to remove gut piles, encouraging tourists to not leave food out, and, perhaps, even employing lasers to deter ravens from wastewater treatment sites and garbage dumps.
At 7:55 pm, President Chaya thanked Dr. Marzluff for his talk and facilitated the Q&A portion of the program in the absence of Vice President Gabriel Willow.
8:20 pm—The meeting was adjourned.
Respectfully submitted by Amy Simmons, Recording Secretary