The “Let’s Talk About Parks” series is designed to encourage exploration and discovery of Pittsburgh’s urban parks.

Spring is officially here, and with the warmer weather, there are all kinds of amazing things to see in your city parks. You’ll see budding trees in Riverview and daffodils in the Highland Park entrance garden. A keen eye will spy saplings with their tender twigs chewed off by hungry deer in Frick Park or trillium sprouts in Schenley Park. The longer days give more time to see your favorite parks as they shift into their spring colors, but it also gives you more daylight time to explore the sounds of your parks. After all, you can only see what is front of you, but you can hear in all directions.

You’ll hear birds that you haven’t heard for months, as species of geese and ducks begin to pass through our region as they return from their southern migration. You’ll hear ruffled grouse and turkeys and barn and tree swallows who are back in our area in great numbers. The scurrying noise you hear may be deer bolting away as they spot humans, and the damp, muddy ground has its own distinct sound as your shoes splotch their way through the woods.

But one of spring’s most distinct sounds is that of the spring peeper. Spring peepers — small frogs that range in size from three-quarters to 1½ inches — are remarkable creatures. They vary greatly in appearance, often visually adapting to their surroundings. They range in color from shades of brown, gray or olive and have been spotted in yellow or reddish orange. Their bellies are white or cream colored and often have a dark cross marking across their backs and dark spotted bands around their legs. Male and female spring peepers can differ in appearance, with females being slightly larger and lighter.

Male spring peepers have a feature that distinguishes them from the females — a small dark flap beneath their throats in the place where their vocal pouches are. During the first warm weeks of spring, as the peepers’ mating season begins, males use their vocal skills to make a distinctive peeping sound. As air fills the pouch, it becomes translucent like a balloon, and the force of the air makes a high-pitched call that some compare to a young chicken or sleigh bells. Spring peepers can be heard not long after the ice first melts in early spring, as they have bodies uniquely made to adapt to the changing seasons. They can survive the freezing of some of their body fluids for short periods of time and have been known to endure temperatures as low as minus 8 degrees.

Spring peepers make wetlands, marshy woods, shallow pools and swampy sections of our parks their habitat. Where they live is a key part to their survival, as they need watery surroundings to reproduce. The male peeper’s loud call attracts the female, ensuring that a new generation comes into the world. Visit lower Frick Park along Falls Ravine Trail or Schenley Park along Hollow Run Trail under the Panther Hollow Bridge to hear the peepers in action in the coming weeks. Their calls can also be heard near the pond on Lake Drive in Highland Park or in the low swampy sections of Riverview Park.

For park trail maps, visit www.pittsburghparks.org.

First Published: March 23, 2016, 3:10 p.m.