Hummingbird in 1990s: Anna’s northward shift
[230] [desk-hummingbird-1] In 1990s, the field log for Hummingbird is headed “Anna’s northward shift.” The figure kept beside that heading is 360. It is a count or a date from the work, not a rank of the species’ worth. A zoo birthday card does not replace the log. Hummingbird biology is a stack of structure, energy, sensing and hard limits. The four sections below are the same headings used acros
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?
John Gould’s 19th-century monographs and skins made trochilids a Victorian craze — with a collecting cost that modern field work still cites. Why do some species have bills longer than the head? Sword-billed hummingbirds match 10–14 cm bills to Datura and Passiflora corollas — a coevolution exhibit, not an ornament.
Keep 1990s, “Anna’s northward shift,” and 360 together or the note on Hummingbird stops being that year’s record.1990s
Figures to keep
- Year of the note
- 1990s
- Figure to keep
- 360
- Species
- Hummingbird
- Line in the log
- Anna’s northward shift
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