Field Highlights » Birds in Winter, Deadwood & Springtails
Season: Winter | Location: New-England’s meadows, forests, parks, and gardens.
EwA runs biodiversity walks monthly when we invite our guests to observe with us the passage of the seasons on the local flora and fauna. Each exploration is a chance to nature chronicles that we may enjoy together right at the time of the walk. 📅 Check EwA’s events calendar and come discover with us the hidden stories of our urban green spaces.
Bird’s strategies to cope with cold
Winter in the woods is a special time. The forest opens up to the sky. As there is less “leaf distraction”, it provides a great opportunity to zoom out and observe birds while thinking about the different adaptations that they have evolved to cope with winter.
Here are a few incredible strategies that bird use:
□ Migration. Leave for a warmer climate
□ Fat reserves. Many birds gorge on food in the fall
□ Feathers. 6 types of feathers, including semiplumes and down
□ Feet. Fewer arteries, mostly tough tendons. Some birds grow extra pads in winter
□ Torpor. Radical decrease in metabolism–some birds even fake death!
□ Shivering. Quick muscle spasms to convert energy into heat
□ Countercurrent heat exchange system: Heat loss is reduced by 90% in a bird’s extremities by reducing the diameter of the arteries in their legs and by an exchange of heat between arteries and veins (that are adjacent in birds).
□ Fluff and tuck. Ever wondered why there are so many headless birds standing on one foot in the winter?
□ Cache for later. Birds like chickadees cache seeds in the fall to prepare for soon-to-be hard times. They’ve adapted to increase their memory capacity each fall by adding new brain cells. The part of the brain that supports spatial memory (hippocampus) can expand around 30% in volume. Every spring, when there’s less need to remember where stuff is, the chickadee’s hippocampus shrinks back to its normal size. Fascinating, isn’t it?
Not so deadwood…
Winter is also the perfect time to zoom in, and start looking in closely at all the small things! In the drawing below, these tiny blobs are globular springtails (possibly of the genus Dicyrtomina). We spotted them while looking for fungi on that deadwood. They are tiny hexapods related to insects. They can be distinguished from other springtail groups by their body shape: round, almost spherical, and usually with long antennae. Adorable! These ones look like they’re guarding that mature beech woodwart (Hypoxylon fragiforme), a fungus often found year-round on dead beech branches (of course!).
Also to look forward to in winter
Signs: White-tailed deer scat
Deer scat comprises small pellet- or pill-shaped droppings often clumped together. It is sometimes confused with rabbit feces, but rabbit droppings are noticeably larger.
Signs: Wood-boring insects
Here, likely to be the track of an elm bark beetle (Scolytus multistriatus)
EwA Useful References & Links
📖 Birds: A Complete Guide to their Biology and Behavior by Jonathan Elphick (2016)
📖 Fascinating Fungi of New England by Larry Millman (2011)
|The EwA Field Highlights are the companions to our biodiversity walks (check out our 📅 event calendar). The field/printable version of this highlight is available here. We generously offer them to our guests, yet they represent a lot of work. If you enjoyed this highlight, please consider 🙏 donating a few dollars to help EwA continue developing them! Thanks. |
Photos and illustrations: © Claire O’Neill | The photos in this article are visual records that the EwA team has collected in the Greater Boston Area. Click on any picture, and you’ll land on the record and its owner. Photos are licensed under Attribution-NonCommercial (CC BY-NC).
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