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Irruptions

I’m completely entranced with this book. Allow me to present an example on the secret life of birds, Goldfinches edition.

I’ve been really enjoying this book: What It’s Like to Be a Bird, by David Allen Sibley, after discovering recently and noticing birds more often on the farm. I love how it’s structured, with a summary of interesting facts by topic (i.e. Plumage, Nesting, Migration, etc) at the beginning, with everything linked (by page number) to various bird profiles that overlap and also interlink to each other as well. You start at some interesting facts on nesting and end up falling down the rabbit hole (never ending bird nest?) into another bird and how they can see at four focal points.

As a short illustration of one of the bird profiles I ended up on, here are a few tidbits on the secret lives of Goldfinches. Enjoy!

All birds molt, but some change their appearance dramatically throughout the season: In the summer the goldfinch grows drab feathers that help camouflage it through the winter. Six months later, in the early spring, before nesting begins, goldfinches molt all of their body feathers again (but not the wing or tails feathers) and males transform into the showy yellow and black colors they need for courtship. Hormones control the switch that allows the same feather follicle to grow very different feathers at different seasons.

The feathers of a goldfinch essentially form a translucent yellow film with backlighting.

Several species of small finches live in the boreal forest across Canada and Alaska, and their life cycle is close tied to the see production of certain species of trees. The trees’ strategy is the produce very few seeds for several years to reduce the population of seed eaters, then produce so many seeds in one year that there is no way they can all be eaten. The Common Redpole is linked to birch trees, which tend to produce large crops of seeds ever other year. With an abundant seed crop more redpolls survive the winter and raise more young, increasing the population, and the following year (when the birches produce few seeds) the redpolls move south in search of food. These unpredictable movements are called irruptions, and are always an exciting event for birdwatchers.

By Nick

I'm a father, husband, son. I love reading, drawing, writing, being active, having a beer or a glass of wine with my wife, and am curious about everything.

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