Species Spotlight: Eastern Red Bat
To celebrate the run up to Halloween, we want to shine the moonlight on each of the eight bat species of Ontario. In this series of blog posts, we will be highlighting the key info for each species and will provide some exclusive recordings we have collected this year in our Batacea Guelph Bat Watch project.
In this post, we will be spotlighting the eastern red bat (scientific name: Lasiurus borealis).
Eastern red bats are multicolored, with striking yellow-red-orange and yellow-greyish fur. They have small, rounded ears, a furred face and tail membrane and males are usually a brighter color than females.
Range and Ecology
Eastern red bats are a common species and in Canada, can be found in Alberta, Saskatchewan, Manitoba, Ontario, Quebec, New Brunswick and Nova Scotia. When they are not migrating to warmer regions in the winter, they can be found in deciduous forests, coniferous and mixed forests.
In terms of roosting, they prefer to roost at the top of trees suspended from branches, where they are often mistaken as being dead leaves or pinecones. In the summer months, females find maternity roosts in trees or shrubs where they stay until mating season again.
Eastern red bats are generalist foragers, and tend to feed on a wide variety of flying insects including moths, beetles and mayflies. In southern Ontario, they are known to consume economically important pest species, including defoliators such as gypsy moths (Lymantria dispar) and tent caterpillars (genus Malacosoma).
During our 2020 surveys, we were lucky to find an eastern red bat roost and observed them leaving their tree roost just after sunset to forage on flying insects.
This species is currently classified as 'Least Concern' according to the IUCN Red List, with stable long-term population trends. Similar to the two other migratory species we have previously featured (hoary and silver-haired bats), eastern red bats are less susceptible to white-nose syndrome (WNS). This may result from the fact they lead more solitary and roost in trees rather than congregating in cool, damp caves which favors the WNS fungus.
Throughout our 2020 summer surveys, eastern red bats were mainly recorded at one of our forested survey sites, making up 8.7% of the total number of recordings for 2020.
Spectrograms from eastern red bats typically range between 35-60 kHz, with the peak energy of the call around 45 kHz. This species has a wide repertoire of calls and sometimes they can produce flatter calls around 30 kHz without the higher frequency sweep.
To listen to the eastern red bat call snippet above, download the MP4 file below.
To explore more eastern red bat spectrograms, check out the iNaturalist Bat Spectrogram project.