Gardening is one of my hobbies, and like birding, it may be to excess.

My hobby provided great fresh vegetables. However, zinnias, gladiolus and canna offer me rewards as well. Almost a third of the garden is some type of flower.

I really enjoy watching the insect activity generated by a big nectar source. Honeybees, bumblebees, hummingbirds, and a “ton” of butterflies are always to be found. Black and yellow tiger swallowtails, cabbage butterflies and monarch butterflies feast on my flowery buffet.

I may seem to paint a gloomy picture sometimes when I write of many bird species’ decline, but it isn’t imaginary.

Well, unfortunately, probably the most commonly known, the monarch has seen a steep decline in its numbers, too. “Monarch” numbers have tumbled over the past 20 years.

Unlike the bird species that are losing ground due to tropical deforestation, monarchs are in trouble here in the U.S. and Canada.

Monarch caterpillars feed solely on milkweed. Milkweed was common along fence rows, in damp meadows and hay fields. With a rapidly growing human population, we keep expanding into these areas and less and less milkweeds are surviving. (No food, no caterpillars, no monarchs.)

Studies in the Central Highlands of Mexico, to where all the eastern monarchs migrate, have revealed critically smaller numbers. Trees, shrubs and the forest floor are covered with the shimmering insects. But this mass of monarchs had shrunk to 1.7 acres about 10 years ago.

The last study, three years ago, showed some promise, with about 10 acres of monarch-covered habitat. Even hawk watchers at Bake Oven Knob were noticing their reduced numbers. I remember one mid-August afternoon my father and I sat in our small rowboat on Beltzville. In the few hours we fished, I’m certain hundreds of them fluttered by us heading south west. That was probably about 1979. Today, I am thrilled to see a few drift over my yard or fly across the street.

Monarch butterfly life history: In spring, the monarch adults fly north, mate and lay eggs on milkweed plants. The caterpillars feed, mature and pupate in a chrysalis. Adult butterflies emerge, fly farther north and repeat the process.

Eventually monarchs appear in the Times News area and northward. The adults from our area are the ones who begin their long trip to Mexico in August. Amazingly, these adults find their way back to the same Mexican mountain and were never there before. This trip may take two months or longer, sometimes they even cover 200 miles a day.

Black swallowtails are rather common locally, but don’t have the migratory habits. They, like all butterflies, undergo complete metamorphosis (egg stage, larva stage — caterpillar, pupa stage — chrysalis, and adult). Black swallowtails feed almost exclusively on carrot relatives, such as Queen Anne’s lace, parsley, parsnips, dill, etc.

In that respect gardeners might consider them to be a pest, although they don’t incur too much monetary loss. Black swallowtails have two generations. In other words, there are two adult stages each year. The second adult stage lays eggs and the insect survives the winter in its chrysalis to emerge in spring.

The yellow tiger swallowtail is the largest of the three. They too have two generations here, and probably are the quickest and strongest fliers. They quickly move from flower to flower. Their caterpillars eat leaves of cherry, linden, tulip poplar, etc. and generally are not considered an insect pest.

Look for these three species the next few weeks and cross your fingers the monarchs keep rebounding so you can still see them migrating even into mid-October.

Test Your Outdoor Knowledge: I mentioned that a butterfly emerges from a chrysalis. What does a moth emerge from?

Last Week’s Trivia Answer: As in most spiders, insects, and birds, the female praying mantis is larger than the male.

Contact Barry Reed at breed71@gmail.com.