Little brown bat activity patterns and conservation implications in agricultural landscapes in boreal Yukon, Canada

Abstract

Agriculture can threaten the persistence of bat populations by removing forests and wetlands and by intensifying production. Both processes are underway in expanding agricultural landscapes of boreal North America.To inform land planning and agricultural practices aimed at maintaining a viable population of the little brown bat (Myotis lucifugus), we assessed the use by bats of human-modified (open fields, forest-field edges, and cleared edges of ponds) and unmodified (forest ponds and forest interior) habitat features in agricultural landscapes in southern Yukon, Canada (60 N-61 N), using acoustic recordings. We summarized bat activity (number of 3-s acoustic files with ≥1 pass/night) and bat feeding (files with >1 feeding buzz/night) at grouped sets of habitat features (sites) and used generalized linear mixed models to test predictions about relative use of habitats. The active season for bats was late April to early October. Little brown bat feeding was strongly correlated with general activity, but feeding comprised a significantly higher proportion of all activity at forest ponds and forest interiors compared to field edges, open fields, and ponds in fields. Total bat activity was highest at forest ponds, followed by field edges, and substantially less in forest interiors and open fields. Forest ponds were used more than the edges of nearby ponds with some riparian clearing for fields. Bats increased use of forest interiors and decreased use of fields as duration of darkness decreased close to summer solstice. We recommend exclusion of ponds, lakes, and other wetlands from future agricultural land disposition, and retention of a riparian forested buffer of ≥40 m around current water bodies on farms. We also recommend retention of strips or patches of forest bordering fields and connected to riparian areas and to more extensive forests on public lands. A relatively young agricultural landscape can avoid some of the risks of intensive agriculture with proactive planning and stewardship.

In the Spotlight: Bat Activity Shifts in Response to Intense Lighting of a Large Railway Construction Site

“…These species are known to be attracted to light sources in urban environments and along illuminated roads, benefitting from insect congregations around the lights [29][30][31]. The high activity levels recorded at the construction site suggest these species likely use the site's lighting installations as foraging grounds [32,33]. The construction site's lighting system has therefore altered their habitat selection, with potential dramatic consequences on nocturnal insect populations [34].…”

The influence of climate and the presence of predators on the daily activity pattern of collared peccaries (Dicotyles tajacu, Cetartiodactyla)

“…The collared peccary is endangered in certain Brazilian states, such as Minas Gerais (COPAM, 2010), but it is not considered to be at risk of extinction by the Red List of Threatened Species of Brazil (Ministério do Meio Ambiente, 2022). Evaluating the daily activity patterns of collared peccaries and their predators has implications for their conservation, because we can assess the indirect and direct effects of the presence of humans and domestic dogs on the behavioural strategies of the animals, as well as evaluating which species are most at risk from anthropogenic disturbances (Gilbert et al., 2023; Slough et al., 2022).…”