Person: O'Mara, M. Teague
O'Mara, M. Teague
Loading...
Email Address
Affiliation
ORCID
Birth Date
Job Title
Last Name
O'Mara
First Name
M. Teague
Creator of
Editor of
Reviewer of
Copyright Holder of
Data Contributor of
Funder of
Translator of
Other Contributor of
3 results
Search Results
Now showing 1 - 3 of 3
- Data packageData from: European free-tailed bats use topography and nocturnal updrafts to fly high and fast(2021-02-04) O'Mara, M. Teague; Amorim, Francisco; McCracken, Gary F.; Mata, Vanessa; Safi, Kamran; Wikelski, Martin; Beja, Pedro; Rebelo, Hugo; Dechmann, Dina K.N.During the day, flying animals exploit the environmental energy landscape by seeking out thermal or orographic uplift, or extracting energy from wind gradients. However, most of these energy sources are not thought to be available at night because of the lower thermal potential in the nocturnal atmosphere, as well as the difficulty of locating features that generate uplift. Despite this, several bat species have been observed hundreds to thousands of meters above the ground. Individuals make repeated, energetically costly high-altitude ascents, and others fly at some of the fastest speeds observed for powered vertebrate flight. We hypothesized that bats use orographic uplift to reach high altitudes, and that both this uplift and bat high-altitude ascents would be highly predictable. By superimposing detailed three-dimensional GPS tracking of European free-tailed bats (Tadarida teniotis) on high-resolution regional wind data, we show that bats do indeed use the energy of orographic uplift to climb to over 1,600 m, and also that they reach maximum sustained self-powered airspeeds of 135 km h−1. We show that wind and topography can predict areas of the landscape able to support high-altitude ascents, and that bats use these locations to reach high altitudes while reducing airspeeds. Bats then integrate wind conditions to guide high-altitude ascents, deftly exploiting vertical wind energy in the nocturnal landscape.
- Data packageData from: Overall dynamic body acceleration in straw-colored fruit bats increases in headwinds but not with airspeed(2019-05-21) Scharf, Anne K.; Fahr, Jakob; Abedi-Lartey, Michael; Safi, Kamran; Dechmann, Dina K.N.; Wikelski, Martin; O'Mara, M. TeagueAtmospheric conditions impact how animals use the aerosphere, and birds and bats should modify their flight to minimise energetic expenditure relative to changing wind conditions. To investigate how free-ranging straw-colored fruit bats (Eidolon helvum) fly with changing wind support, we use data collected from bats fit with GPS loggers and an integrated triaxial accelerometer and measure flight speeds, wingbeat frequency, and overall dynamic body acceleration (ODBA) as an estimate for energetic expenditure. We predicted that if ODBA reflects energetic expenditure, then we should find a curvilinear relationship between ODBA and airspeed consistent with aerodynamic theory. We expected that bats would lower their airspeed with tailwind support and that ODBA will decrease with increasing tailwinds and increase with wingbeat frequency. We found that wingbeat frequency has the strongest positive relationship with ODBA. There was a small, but negative, relationship between airspeed and ODBA, and bats decreased ODBA with increasing tailwind. Bats flew at ground speeds of 9.6 ± 2.4 ms-1 (mean ± sd, range: 4.3 to 23.9 ms-1) and airspeeds of 10.2 ± 2.5 ms-1, and did not modify their wingbeat frequency with speed. Free-ranging straw-colored fruit bats therefore exerted more total ODBA in headwinds but not when they changed their airspeed. It is possible that the flexibility in wingbeat kinematics may make flight of free-ranging bats less costly than currently predicted or alternatively that the combination of ODBA and airspeed at our scales of measurement does not reflect this relationship in straw-colored fruit bats. Further work is needed to understand the full potential of free-ranging bat flight and how well bio-logging techniques reflect the costs of bat flight.
- Data packageData from: Greater spear nosed bats commute long distances alone, rest together, but forage apart(2023-08-22) O'Mara, M. Teague; Dechmann, Dina K.N.Animals frequently forage in groups on ephemeral resources to profit from social information and increased efficiency. Greater spear-nosed bats, Phyllostomus hastatus, develop group-specific social calls, which are hypothesized to coordinate social foraging to feed on patchily distributed balsa flowers. To test this, we tagged all members of three social groups of P. hastatus on Isla Colo n, Panama , using high-frequency GPS during a season when balsa had begun to flower. We found that bats commuted 20-30 km to foraging sites, more than double the distance reported previously. In contrast to our expectations, we found that tagged individuals did not commute together, but did join group members in small foraging patches with high densities of flowering balsas on the mainland. We hypothesized that close proximity to group members would increase foraging efficiency if social foraging were used to find flower clusters, but distance between tagged individuals did not predict foraging efficiency or energy expenditure. However, decreased distance among tagged bats positively influenced the time spent outside roosting caves and increased the duration and synchrony of resting. These results suggest that social proximity appears to be more important during resting and that factors other than increased feeding efficiency may structure social relationships of group members while foraging. It appears that, depending on the local resource landscape, these bats have an excellent map even of distant resources and may use social information only for current patch discovery. They then may no longer rely on social information during daily foraging.