Owl Box

There are seven species of owls that regularly occur at various times of year in northcentral Pennsylvania: great horned, barred, barn, long-eared, eastern screech, saw-whet and short-eared. Even the short-eared owl breeds here, but only at two sites; most shortys come south in winter in search of food.

There's usually also an influx of saw-whets during the winter as northern birds come south in search of the small rodents on which they feed. We occasionally get one or more snowy owls during the winter when they drift south from the arctic.

Of the seven species that are regularly found here, the short-eared owl and barred owl are my favorites – probably because those are the owls I see most often. Short-eared owls are open-country birds, hunting and nesting in hayfields and marshes. Barred owls are birds of the woodlands, preferring cavities in large trees for nesting and roosting.

The many acres of the forests surrounding our son and daughter-in-law’s place is suitable habitat for barred owls –

But those woodlands don't have an abundance of large trees containing cavities.

So, having a stack of used lumber in the garage, it was time for me to make a nesting/roosting box suitable for a barred owl. Plans for these boxes are readily available – here’s one from the Minnesota DNR’s Woodcrafting for Wildlife –

The wood I had was what’s sold as spruce-pine-fir, not at all decay resistant; I used some scraps of drip edge and left over shingles to help keep rain and snow off the roof, and modified the plan to create a slanted roof to shed rain more effectively. These modifications should help the box last longer –

A branch was fastened to the front of the box because young owls do what is called “branching”. The owlets leave the nest before they can fly and spend several weeks clambering on tree branches; the parents continue to feed them until the owlets get stronger and learn to fly.

We went north for a visit and one fine day our son, who has a wealth of climbing experience, went up a sugar maple to install the owl box –

Hopefully, a barred owl will find the box suitable and raise some owlets in the cozy abode.

Regal

Monarch butterflies have been in the news during the last few years because they’re beautiful, most people have seen them, most migrate to spend the winter in Mexico and their population has been in decline –

There are other common orange butterflies, the fritillaries, that spend the summer flying over fields in Pennsylvania. Five species of fritillaries are relatively common in northcentral Pennsylvania, the most abundant being the great spangled fritillary –

While there are many species of fritillaries in the western states, five species are all we have here. But there’s one more fritillary that can be found in Pennsylvania if you know where to look and get permission to look. That species is the regal fritillary –

The regal fritillary was once found from Massachusetts to Virginia and west to Kansas and the Dakotas. It’s declining everywhere and has vanished east of the Mississippi except for one very small area in southcentral Pennsylvania.

The regal fritillary’s larvae feed on violet leaves, primarily on the leaves of the arrow-leaf violet –

The adults are less picky and feed on the nectar of a number of species of plants, preferring butterfly milkweed and pasture thistle –

These butterflies are dependent on disturbed sites containing little bluestem grass, broomsedge and their host plants ... sites maintained by periodic fire and heavy disturbance.

In Pennsylvania the regal fritillary inhabits a small area of suitable habitat in a restricted area which is only open for a few days each year and only to those limited few with permits. I happened to get one of those permits and spent part of a morning searching for the butterflies with a few other folks and our escorts.

We found quite a few regal fritillaries and many other more common butterflies –

As well as some hummingbird clearwing moths that fly during the day and feed on nectar –

But the regals were our real objective, and we were quite successful in finding them –

Most of the butterflies we saw were males with one row of white spots and another row of orange spots on their hind wings. The females with two rows of white spots on their hind wings were just beginning to emerge from pupation –

Regal fritillaries mate in midsummer, the females then scatter their eggs. The eggs hatch in the fall and the tiny larvae overwinter in the plant debris on the ground. The following spring the larvae feed, pupate and give rise to a new generation of regal fritillaries –

Habitat loss is considered to be the primary cause of the species’ decline so the existing habitat is closely monitored and managed. The regal fritillary is endangered although official recognition of that fact will be a while in coming. Hopefully another suitable site will be located and a second population can be established to ensure that the species will continue to be part of Pennsylvania’s fauna.

National Moth Week

It’s that time of year again, National Moth Week (Saturday July 18, through Sunday, July 26), time to look at the great variety of night flying insects that we call moths. Moths form the largest portion of the group of insects known as Lepidoptera, the remainder of the group are the butterflies, which evolved from day-flying moths.

There are approximately 12,000 named species of moths in North America and an unknown number of as yet undescribed and unnamed species. Moths are essential to a healthy ecosystem: moth larvae are an extremely important food for nestling songbirds, moths (not mosquitoes) are a primary food of bats and many plants depend on moths for pollination. Only a handful of moths are what might be called pests; the vast, vast majority are either innocuous or beneficial.

While some moths are small and drab, others are large and colorful and others are a combination. Here’s a sample of interesting moths –

Moths are in serious trouble from pesticides, superfluous lights at night and habitat loss. Lawn care chemicals, recreational mowing of large lawns and outdoor lights when nobody’s awake have serious adverse impacts on moths – and those impacts spread through the ecosystem.

To sample the moths around your house leave an outside light on for a couple of hours after sunset and see what moths are hanging on the wall. Then don’t forget to turn off the light so moths can spend the rest of the night doing what moths do.