Bioacoustics Almanac — April Listening Together Project
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First Week of April
After spending the winter in their lodges, muskrats begin to be visible in marshes in early spring. One often notices them first by hearing their splashes and peeping sounds. Muskrats live in family groups in lodges that are up to a meter high and have two or more underwater entrances. The population of muskrats can fluctuate considerably due to a complex natural cycle resulting from changes in food availability, mink predation, disease (Painting: Louis Agassiz Fuertes; Sound: Yukon Government).
The Song Sparrow returns to Nova Scotia in late March. By the first week of April, this common bird can be heard singing in a wide variety of habitats throughout the province. For many people, it is one of the most well-known signs of spring (Painting: Louis Agassiz Fuertes; Sound: Xeno-Canto, Thomas Ryder Payne).
Second Week of April
The Red-winged Blackbird is likely to be found in the vicinity of muskrats as they both prefer cattail marshes. With its red shoulder patches the male is very distinctive, singing frequently, from a high perch. The female is more furtive, often keeping to the lower regions of the reeds (Painting Louis Agassiz Fuertes; Sound: Xeno-Canto, Thomas Ryder Payne).
The Savannah Sparrow nests in grassy fields. It is similar to the Song Sparrow but is slightly smaller with a distinct yellow line over the eye. Unlike the melodious Song Sparrow, this species has a more raspy voice that is almost insect like (Painting by Marion Aitken; Sound by John Kearney).
Third Week of April
Yellow-bellied Sapsuckers are found primarily in deciduous forests. You have likely noticed the bark of trees, like white birch, with extensive lines of holes in them. These are sapsucker sap wells. Sap is a primary food of this species, except when they are feeding their young who are brought insects (sometimes coated with sap) by their parents. They drum like other woodpeckers but the drum distinctly slows down near the end. Female sapsuckers will occasionally drum also. Like other woodpeckers, Yellow-bellied Sapsuckers play an important ecological role in our forests. Their sap wells are an important source of food for insects and hummingbirds, while their abandoned nest cavities are used by other wildlife (Painting: Louis Agassiz Fuertes; Sound: Xeno-canto, Jim Berry).
The Winter Wren inhabits the undergrowth of moist, dark, mature and old-growth coniferous and mixed coniferous-hardwood forests. It’s drab plumage and sulking behaviour makes it difficult to see. But when it sings, its long, loud, melodious song fills the forest as if a virtuoso was giving a special performance for its inhabitants. However, forest practices that turn the landscape into clearcuts and young forests make much less habitat available for this species (Painting Louis Agassiz Fuertes; Sound: Xeno-Canton, Martin Saint-Michel).
Fourth Week of April
The Northern Leopard Frog starts calling in mid-April in ponds and shallow coves. They are bright green with black oval spots. In the summer, leopard frogs often move to grassy fields and meadows, returning to aquatic environments in the fall for hibernation (Photo: Nova Scotia Museum; Sound: Ontario Nature).
The Palm Warbler is among the first warblers to return in the spring from its wintering grounds in the southeastern United States. It is unique among warblers in that it spends much of its time on the ground or in low shrubs, and there is no difference in the plumage of males and females. It makes up for this in having two distinctly different populations in Canada, the Yellow Palm Warbler and the Western Palm Warbler. These two populations nest east or west of Ottawa respectively. The Yellow Palm Warbler has a yellow belly while the Western Palm Warbler has a white belly (Painting: Louis Agassiz Fuertes; Sound: Xeno-Canto; Andrew Spencer).