Offshore Observations of Eastern Red Bats (Lasiurus borealis) in the Mid-Atlantic United States Using Multiple Survey Methods

Abstract

Little is known about the migration and movements of migratory tree-roosting bat species in North America, though anecdotal observations of migrating bats over the Atlantic Ocean have been reported since at least the 1890s. Aerial surveys and boat-based surveys of wildlife off the Atlantic Seaboard detected a possible diurnal migration event of eastern red bats (Lasiurus borealis) in September 2012. One bat was sighted approximately 44 km east of Rehoboth Beach, Delaware during a boat-based survey. Eleven additional bats were observed between 16.9 and 41.8 km east of New Jersey, Delaware, and Virginia in high definition video footage collected during digital aerial surveys. Observations were collected incidentally as part of a large baseline study of seabird, marine mammal, and sea turtle distributions and movements in the offshore environment. Digital survey methods also allowed for altitude estimation for several of these bats at >100 m above sea level. These observations provide new evidence of bat movements offshore, and offer insight into their flight heights above sea level and the times of day at which such migrations may occur.

Consolidating the State of Knowledge: A Synoptical Review of Wind Energy’s Wildlife Effects

“…However, as soon as bats flew close to vertical structures such as wind turbines, they rapidly increased flight elevation which is likely linked to an accumulation of insects. Contradictory to these findings, Hatch et al ( 2013 ) who observed bats flying 16.9–41.9 km off the coast reported that migratory bats flew at relatively high altitudes at >100 m (6 bats out of 6) and >200 m (5 bats out of 6) above sea level. Migration behavior took place during daylight also, which might be due to a lack of landing opportunities.…”

Spatial and temporal occurrence of bats in the southern North Sea area

“…As the Dutch/Belgian coastline runs generally between NNE/SSW and ENE/WSW the optimal LM wind direction (170 degrees) is likely to cause funnelling of migrating and foraging individuals from local populations along the coast. The observed optimal wind direction at sea (94 degrees) implies that bats crossing over sea are associated with tailwind, as suggested by Hatch et al (2013). Interestingly, this contradicts the findings of Hüppop &…”

Risk Modeling of Bat Rabies in the Caribbean Islands

“…Many natural and unnatural processes may play a role in the inter-island movements of bats, including natural migrations patterns to areas of higher resource availability (insect or fruit), predation of aerial insects along their migratory trajectories, formation of breeding aggregations, changing of roost site due to human disturbance, or seasonal tropical storms and hurricanes [35,[50][51][52][53][54]. Translocation events caused by human activities have also been observed to occur such as bats roosting in or on shipping containers, ocean vessels, oil platforms, or aircraft [16,55].…”