Hummingbird — Anna’s northward shift · 110
[669] [roadmap-hummingbird-5] How does a 3-gram bird cross the Gulf of Mexico? 110 Sugar water is visible help. Gulf-coast stopover habitat is the crossing’s real fuel depot. 1990s: log Hummingbird under “Anna’s northward shift” with 360. Do not rank the species. Range expansion looks like a win. It also tracks ornamental planting and a milder coast, not a restored wild nectar grid.
New World nectar specialists that hover on figure-eight wings and migrate on a few grams of fat. How can a hummingbird hover when other birds cannot? The shoulder allows a nearly horizontal figure-eight. Lift on the upstroke as well as the downstroke pays the hover bill that a typical avian stroke cannot.
Do hummingbirds live on sugar water alone? No. Nectar is fuel. Arthropods supply protein, especially for chicks. Feeders that omit insects do not replace a territory. How does a 3-gram bird cross the Gulf of Mexico? Ruby-throated hummingbirds fatten, then fly 800+ km nonstop. Tailwinds and a high mass-specific power output make the crossing possible, not a rest on ships.
A controlled drop in body temperature and metabolic rate overnight. Without it, many species would exhaust nectar stores before sunrise. Diversity peaks in the Andes. Anna’s hummingbirds now winter in Vancouver gardens; ruby-throated breed to southern Canada. Who first illustrated hummingbirds for Europe?
Keep 1990s, “Anna’s northward shift,” and 360 together or the note on Hummingbird stops being that year’s record. 1990s: log Hummingbird under “Anna’s northward shift” with 360. Do not rank the species. 3601990s
Figures to keep
- Year of the note
- 1990s
- Figure to keep
- 360
- Species
- Hummingbird
- Line in the log
- Anna’s northward shift