Green frog calls, tiny toads emerging

Talk about it

Mid-July is best known for its summer heat. These are the hot days that send us to air-conditioned protection, one of the few times when we speak more of heat in the Northland than of the chill. But mid-July is also a time of many more nature happenings.

It is now that the wildflowers, so abundant in fields and roadsides, blend a mixture of summer milkweeds, fireweeds, bergamots and evening primroses with the beginning of sunflowers, goldenrods and asters that will continue into the late summer and fall. The strawberries of early summer have faded to be replaced by blueberries, juneberries, raspberries and pin cherries.

These wild foods are gathered by many other local critters besides us, and a good patch may not last long. Mushrooms that began in the wet conditions of June have now become more widespread and diverse and their kinds will continue into coming weeks as well.

Bird songs, used daily as a proclamation of territorial ownership from early in the breeding season, are now waning; only persistent red-eyed vireos, wood peewees and a scattering of others continue. And the summer frogs fill the night with their sounds, differing much from those of the spring.

My regular visits to the lake are never silent. In the morning I’m greeted by the “knock knock” call of mink frogs. And when I return at dusk, the green frogs are strumming their banjo-plucking sound well into the night.

Recently, during a full-moon night, I visited the lake at 2 a.m. The summer night was bright and mild and I listened for a while. In addition to the nocturnal loon calls that we are so used to, the green frogs filled the night with their own sounds. Their numbers seem to be greater than I’ve heard in years.

During the next few days, I visited many other lakes and various wetlands and at nearly every one, I heard the green frogs. I cannot remember a July when I’ve heard more green frogs, and in more places, than this year. They appear to have taken advantage of the hard rains of last month and dispersed into the larger expanses of water.

Frogs breeding in summer will lay eggs hatching later in the season, but their tadpoles will need to overwinter before emerging as adults a year from now. With this type of life cycle, green and mink frogs need to live in large bodies of water. They are residents of lakes, swamps and ponds that retain water.

This is not the situation with many of the spring frogs and toads that breed in ephemeral vernal ponds that hold snow-melt water in spring, but drying later in summer. (This year many of these ponds may be more permanent.) Eggs of spring need to hatch and develop rapidly before their aquatic habitat ceases.

Each July, I look for the products of spring in addition to the frogs of summer. And it happened again this year. The day after my late-night vigil with green frogs at the lake, I was walking on the road and discovered a tiny anuran hopping by. Capturing and examining it, I was able to determine that it was a tiny American toad. The minute critter was about the size of a finger nail. I estimated that it had just left the nearby water sometime that day. This happens every July, but this one was earlier than normal. Others of its kind will be dispersing over the region soon. And we’ll be seeing their small hoppings in roads and yards as they move on to their next phase of life.

Here in mid-July, we are seeing the product of last spring’s eggs and hearing the calls of those still laying eggs in summer. While the adult green frogs congregate to call in the wetlands, the young toads leave the water for life on land. Frogs and toads continue in the changing seasons.

Retired teacher Larry Weber is the author of several books, including “Butterflies of the North Woods,” “Spiders of the North Woods” and “Webwood.” Contact him c/o news@pinejournal.com.

Tags: carlton county, outdoors