Each week, staff phenologist John Latimer brings his delightful and comprehensive phenology reports to the airwaves. Phenology is the rhythmic biological nature of events as they relate to climate: it's all about seasonal changes in nature. Please enjoy John’s full report by clicking ‘play’ above!
Charlie Mitchell, KAXE’s phenology coordinator, provides additional information below.
The bird with the twisty bill
To my delight, crossbills have been visiting feeders in Northern Minnesota this winter. While they are regular winter visitors, they tend to hang out in the woods and are leery of visiting feeders. Therefore, observing them is more of a “let’s go on a hike” enterprise than a simple “glance out the window” one.
Crossbills get their names from their wacky beaks, which look like some mythic trickster tried to use them as a twist-tie before getting bored and wandering off.
These seemingly misaligned tips of their beaks are the perfect tool for prying open tightly sealed cones of pines, spruces, and other conifers. These cones are full of seeds: the primary diet of crossbills.
Crossbills’ specialization has allowed them access to food few other animals can get to. So, when cone crops are good, they don’t bother waiting for the traditional breeding season. If they find a spot with plenty of food, they’ll nest and raise chicks in the middle of winter! (Conveniently, their chicks also eat seeds.)
It’s hard to digest food in a big lump, though: it helps to grind it up to a manageable size. Lacking teeth, crossbills and other birds will ingest grit, which sits in their gizzards and mashes their food to a more digestible size. You may see crossbills on the side of roads, where they can find small pieces of grit and gravel.
(It’s on my outdoorsy bucket list to watch them try to pick up gravel with their wonky beaks! Apparently, they have to use the side of their bills to get a good grip.)
We have two species of crossbills in Minnesota: the Red Crossbill and the White-winged Crossbill. It doesn’t take long to get complicated, though: within the Red Crossbill population are about 10 subgroups, called “call types,” “ecotypes,” or – more simply - “types”. These subgroups rarely interbreed, use different calls, and tend to prefer feeding in different types of conifers. Current research is aimed at determining if these are separate species, a group in the process of diverging into different species, or just a wacky population with a lot of variation within it.
(If you ever want a very convoluted but passionate rant, ask an evolutionary biologist to define a “species”. Even better, ask two of them, then sit back with some popcorn and enjoy the show.)
Have you seen the crossbills this winter? Let us know, so I can live vicariously through you!
There’s more!
John also discussed:
- Climate weirdness and the resilience of plants (0:26-2:55)
- Beginning buds (2:55 – 4:10)
- Magnificent trees (4:10-6:23)
- Huge flocks of waxwings and their behaviors (6:23-8:25)
- Crossbills! (8:25-9:48)
- Trumpeter swans everywhere and their conservation story (9:48-10:51)
- Gray-crowned Rosy-Finch and Varied Thrush sightings (10:52-12:06)
- Northern Saw-whet owls (12:06-13:19)
- Lack of snow (13:19-14:25)
- Roadside colors (14:25-15:28)
- Miscellaneous reports (15:28-16:39)
- Common Redpolls
- Road killed raccoons
- Skunks
- Snow Buntings
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).
