Predatory songbirds: Northern and Loggerhead Shrikes
During last Saturday’s phenology walk with John Latimer at Rice Lake National Wildlife Refuge, members of the Bee-Nay-She Bird Club spotted a rare (in our area) Loggerhead Shrike! Even better, they had the chance to see it kill, carry, and eat a red-bellied snake.
Loggerhead Shrikes, a critically imperiled species in Minnesota, is far more rare than the Northern Shrike, which is a yearly winter resident. The Loggerhead Shrike is a summer resident in the state. According to the Cornell Lab of Ornithology’s compendium “All About Birds”, the Loggerhead Shrike “has become quite rare in the Northeast and upper Midwest and finding it there is much more problematic.”
To distinguish between the two species, first, think about the season. In mid-winter, Loggerhead Shrikes have long since migrated south, while Northern Shrikes have arrived from their breeding grounds in Canada to hunt the snowy fields and busy birdfeeders of Minnesota. In mid-summer, the opposite is true: Loggerhead Shrikes are here, but Northern Shrikes are not.
In spring and fall, when both species are possible residents, look closely at the black eye mask. Loggerhead Shrikes’ thick eye masks run from the side of the head, through the eye, and all the way to the base of the bill without changing much in width. Northern Shrikes have a shorter eye mask, which is a thick band from the side of the head to the eye, then narrows and fades as it reaches bill. In addition, Northern Shrikes are larger, have thin, light barring on the chest, and white-grey feathers at the top of the bill, while Loggerhead Shrikes are smaller, white-chested, and have black feathers lining the top of the bill.
A murder mystery
Meanwhile, the students at Baxter Elementary reported that they found a dead Red-winged Blackbird; they wondered if a Northern Shrike was responsible.
Intrigued, I did a bit of digging online – this is what I learned. According to the Cornell Lab of Ornithology, Northern Shrikes have been observed taking down birds larger than themselves, such as the American Robin, Blue Jay, and Pine Grosbeak. So, Red-winged Blackbirds seem like a reasonable prey item, though they aren’t noted in Birds of the World as one of the shrike’s prey species.
A clue would be if the carcass had been eaten at all, and if so, which parts are missing; Apparently, shrikes start at the head and work down the body from there. I’d also weigh the availability of insects, as they apparently switch to being mostly insect-eaters in the summer. News to me!
Topics
- Introduction (0:00-0:25)
- Frog chorus (0:25-1:31)
- Phenology walk at Rice Lake National Wildlife Refuge (1:31-6:25, 12:58-13:12))
- Loggerhead Shrike eats a red-bellied snake (4:17-6:25)
- Plant development (2:22-4:03, 14:28-19:26)
- At Rice Lake National Wildlife Refuge (2:22-4:03)
- Fly honeysuckle (2:43-4:03)
- In Grand Rapids (14:28-19:26)
- Birds (4:03-12:58)
- At Rice Lake National Wildlife Refuge (4:03-6:25, 12:58-13:12)
- Hummingbird feeders (6:25-8:45)
- Bird arrivals in Grand Rapids (8:45-10:26)
- How to identify female Red-winged Blackbirds (8:54-10:26)
- Bald Eagle nest update (10:26-12:31)
- Great Blue Heron and Trumpeter Swan (12:31-12:58)
- Insects (13:12-14:28)
- Dragonflies (13:12-13:29)
- Ant phenology! (13:29-14:08)
- Butterflies (14:08-14:28)
- Spring is right on schedule (15:02-15:22)
- Conclusion (19:26-20:20
That does it for this week! For more phenology, subscribe to our Season Watch Newsletter or visit the Season Watch Facebook page.
Funding for this project was provided by the Minnesota Environment and Natural Resources Trust Fund as recommended by the Legislative-Citizen Commission on Minnesota Resources (LCCMR).
