Guide

Listen forAmphibians

Wood frogs quacking at a vernal pool on an accessible trail

March to April

In early spring, wood frogs crowd into vernal pools and call in a raucous chorus that sounds like quacking ducks. Mass Audubon's All Persons Sensory Trail at Broad Meadow Brook Wildlife Sanctuary passes the Holdredge Vernal Pool, on a surface of packed gravel and boardwalk.

Why this time of year

The Vernal Pool Association says to listen for wood frog choruses at vernal pools in March and early April, and that the frogs call at night and on warm days. Mating and egg laying are over within a few weeks, so the chorus does not last.

How to notice it

  1. Follow the All Persons Sensory Trail from the butterfly garden toward the Holdredge Vernal Pool, stop short of the edge, and listen for a chorus that sounds like ducks.
  2. If the frogs go quiet when you arrive, stand still and wait. Wood frogs take cover when disturbed.
  3. Look in sunny, shallow spots for fist-sized jelly blobs stuck to sedges and stems. Each is a wood frog egg mass that can hold up to 1,500 eggs.
  4. Leave the eggs and frogs where they are. By June the tadpoles have legs and start leaving the pool.

Try this with kids: Close your eyes at the pool. Does it sound more like ducks or like frogs?

Phrase to know: A “vernal pool” is a seasonal woodland pool where frogs and salamanders breed.

Sources

  • massaudubon.orgRead 2026-11-10. Mass Audubon (primary, landowner): All Persons Sensory Trail, '1-mile (round-trip)'; 'It's surfaced in alternating packed gravel and boardwalk'; 'begins at the Nature Center butterfly garden and continues along portions of the Holdredge and Frog Pond Trails'; 'The first 0.25-mile section zigzags along a gentle slope'; along the way, Holdredge Vernal Pool: 'spot salamanders or wood frogs'.
  • massaudubon.orgRead 2026-11-10. Mass Audubon (primary): All Persons Sensory Trail 'The surface is packed stone dust with some boardwalk.' 'One of Mass Audubon's ADA-compliant, universally accessible All Persons Trails.'
  • vernalpool.orgRead 2026-11-10. Vernal Pool Association, Belmont MA (nonprofit, secondary, already used elsewhere in the atlas): 'Listen for wood frog choruses at vernal pools in March and early April'; males 'set up a raucous, quacking, breeding chorus'; 'Frogs will call at night and on warm days'; egg mass 'a gelatinous fist-sized blob consisting of up to 1,500 individual eggs' attached to 'tussock sedges and woody stems in sunny locations of a vernal pool'; mating and egg laying 'are completed within a few weeks'; 'By June, these tadpoles will have developed legs and begun their emergence onto land.'
  • massaudubon.orgRead 2026-11-10. Mass Audubon (primary): wood frogs 'Easily identified by their dark masks and loud quacking'; wood frog 'migrates on rainy spring nights to vernal pools to breed'; 'The best time to see a vernal pool is spring.' Gives no months.

Checked against these sources on November 10, 2026.

In the guide for March, April

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