Pick a Bird Brain Series April 18, 2023
Hawk Ridge is famous for the stunning migrations of raptors it witnesses every year. While much research has gone into understanding the timing and patterns of raptor migration, little research has been done to understand the diet of raptors during migration due to logistical research challenges. Advances in the field of molecular biology in the past two decades have opened the door to new methods for studying migratory diet. In this Pick a Bird Brain Program, Lisa Brouellette will discuss the research she conducted at Hawk Ridge for her master’s degree at UMD. Samples taken from birds captured at the Hawk Ridge Banding Station yielded interesting results. There were some surprises, some not so surprising yet telling results, and it definitely identified some shortages of information in the available species DNA sequencing bank. Join us to find out more about migratory raptor diets!
Registration is required for this presentation. Register here.
Recording of program (YouTube)
Periodic Invasions of Northern Goshawks
Ordinarily, hawk count sites do not see large numbers of Northern Goshawks during fall counts because migration is unnecessary with prey species available year round in their home ranges. Juvenile males make up the majority of the goshawks annually seen at hawk watches in most years. However, about every ten years, the normal patterns change in significant ways, and there is over one hundred years of data demonstrating this obvious change which is called an invasion. What does an invasion entail, and what might be responsible for this dramatic change? There is a story here, but even that predictable story is changing as there has not been an invasion observed since the early 2000’s.
Dr. Dick Green will look at historical observations made at three hawk watch sites: Hawk Ridge in Duluth, Minnesota, Cedar Grove in Wisconsin, and Hawk Mountain in Pennsylvania. He will puzzle out the pieces of the story that we know, and also attempt to understand the invasions by looking at the boreal forest community where Northern Goshawks live. Join us to take a look at this fascinating bird mystery!
Registration is required for this event. Register here.
Dr. Richard Green is a Professor Emeritus from the Swenson College of Science and Engineering, Department of Mathematics and Statistics at University of Minnesota, Duluth. He’s long had an interest in birds, visiting the Hawk Ridge Count regularly while he was still in grade school! His research interests are mathematical models in animal behavior and ecology, and he has taught courses in both. In 1982, he visited the Hawk Ridge Count on a day when 1229 Northern Goshawks were counted, in a period where some had predicted there would be no goshawk invasion. This got him asking questions about goshawks and their ecology and the search has continued ever since! He also serves on the Hawk Ridge Bird Observatory Research Committee.
RECORDING OF JAN 24 EVENT
The Secrets that Feathers Hold: Using Feathers to Trace Migration
January 24, 7 pm
At Hawk Ridge an average of more than 60,000 raptors are counted migrating through Duluth each fall, and over 2500 are banded. Some of these banded birds are recaptured at points further south but very few are recaptured or traced to their breeding grounds generally north of Duluth. As a result, very little is known about the distances they travel from their breeding grounds and the timing of their passage through Duluth during migration. Do birds from further north come through earlier than other birds of the same species breeding further south?
In this Pick a Bird Brain Program, Emily Pavlovic will discuss the research she completed for her master’s degree at UMD using a combination of stable isotope analysis and banding return data to learn more about where Northern Saw-whet Owls, Sharp-shinned Hawks and Red-tailed Hawks are breeding, and whether the location of their birth impacts when they are likely to pass through Duluth on their way south.