Wednesday Vignette: Flightless

Gardens are about life and death, not only about pretty plants. My garden emerged from an ecology in which processes of decline and decay are intrinsic, and visible throughout the year. I need to make meaning of the dead tree snags leaning against the sky, water seeping over heavy clay, rot in autumn, the ripe smells of natural fermentation. Although I also have green springs and golden summers and snowy winters, I accept what is given. The processes of decay and making of new life are a governing characteristic, an idea-driver, in my garden.”  James Golden, garden designer/writer in Planthunter, 30 April 2019

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I know that all living things die. I don’t like it, but I know it.

I know that what dies pretty rapidly becomes compost for the continuation of life, as Golden describes above, unless it’s a human buried in a steel vault that doesn’t rupture, in which case an embalmed body might still be preserved and very little decomposed 85 years later or more (don’t look if you don’t want to see dead human bodies). The living — both flora and fauna — literally feed on the dead of all species, as all tissue and bone is still existent in the ecosystem in some form, much of it soil for our crops. Life leads to death, death leads to life.

I know that adult swallowtails live only a week or two after emerging from the chrysalis. It’s a very short adulthood relative to humans’ but it’s apparently enough.

I know that a significant percentage of animals in the wild, including insects, don’t live out their full potential life span, because of predation, pathogens, parasites, starvation, weather, and anthropogenic causes like insecticides, fungicides, herbicides, cars, climate change, habitat loss like deforestation, e.g.

One study found that among 124 herbivorous insect species that undergo a complete metamorphosis — egg, larva, pupa, and adult stages — attack by natural predators was the biggest cause of mortality among immature insects, like caterpillars, at 48%. Another study looks at various anthropogenic causes of monarch butterfly decline, including from loss of milkweed due to genetically modified crops, pesticides, and fertilizers; loss of nectar sources; overwintering habitat threats and habitat fragmentation including road traffic mortality; climate change; and invasive plants. Instructional material on insect life tables notes that “… in a hypothetical insect population, an average female will lay 200 eggs before she dies.  Half of these eggs (on average) will be consumed by predators, 90% of the larvae will die from parasitization, and three-fifths of the pupae will freeze to death in the winter. (These numbers are averages, but they are based on a large database of observations.)” The practice problem at the bottom of that page attributes of a hefty portion of the larvae death due to habitat destruction: a janitor clears away the bubble gum maggots’ gum! ]

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Still, knowing we all die and that most insects live and die fast and that death and decay feeds the living, I can’t really understand the death of this swallowtail, who never had a chance to fly freely or live fully as a swallowtail is meant to do. For whatever reason — bad weather timing (heavy rain the night it emerged); sub-optimal placement of the chrysalis or stalks and stems that shifted during its pupation, leaving it without enough space to fully open its wings when it emerged; or something genetically wrong with this swallowtail — its left-side wing didn’t dry properly. The rest of the butterfly is strong: It’s crawled 10 or 20 yards in the past 36 hours; yet it will soon die, if it hasn’t already, not far from where it emerged — after surviving as a tiny vulnerable egg for 3-7 days, as a caterpillar molting (and eating its way) through five instar phases over 2-5 weeks in a garden full of predators, and as a chrysalis for another week or two.

“It is believed that the caterpillar stage is the most dangerous in the life cycle of a butterfly as the mortality rates are very high. Caterpillars are subject to weather conditions, disease, parasites and predators. Many adult butterfly species lay hundreds of eggs with only a few surviving to become adults.” (source)

It had made it through these stages, where it’s most vulnerable, only to end up moments away from its first flight, too damaged to get off the ground. It’s heart-breaking when you think about it.

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Wednesday Vignette is brought to us by Flutter & Hum.

3 comments

  1. I think the part in your post about luck/circumstances/timing, or the lack thereof, is the perfect supplement to what I wrote this morning. There are so very many reasons things can go wrong, even with the best of intentions or fortuitous beginnings. Great post!

  2. One of the difficulties of my work is condemning old oaks that have lived in the Santa Clara longer than just about anything else that is there now. Seriously, some of these trees were born when San Jose was a small town. For most, their demise was accelerated by nearby development and landscaping. For some, their death is completely natural. Regardless, it is sad to see something that has always been there succumb.

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