Data from: Macro-evolutionary trade-offs as the basis for the distribution of European bats

We have compiled a dataset of life history traits and distribution characteristics of 30 European bat species, based on a literature study of a total of 56 primary and secondary sources. These life history traits are grouped into morphological, physiological and ecological adaptations. 

Physiological adaptations:

Neonatal mass: the average weight (g) of a newborn pup, measured within five days after birth.

Average litter size: the average size of a full-term litter (including stillborn pups) per female.

Weaning mass: the weight (g) of a juvenile during its first flight outside the roost.

Adult body mass: the average weight (g) of adult bats during the summer (between 1 May and 1 July), excluding pregnant females.

Litter mass: neonatal mass * average litter size.

Relative mass of neonatal to adult: neonatal mass*100 / adult weight

Relative mass of litter to adult: litter mass*100 / adult weight

Gestation: the length of gestation period (in days), from fertilisation to birth. When mated during autumn or winter, the sperm (or fertilised egg in M. schreibersii) is stored throughout the winter. On arousal from hibernation in the spring, around mid March, female bats ovulate and gestation begins. In accordance with other researchers (e.g. Altringham 1996, Entwisle et al. 1998), 15 March was used as the start of the gestation period, for statistical reasons we also included M. schreibersii.

Weaning: the length of the lactation period (in days) until offspring are fully independent. After the juveniles are capable of flight, mothers continue to give their young nourishment until they are fully independent. Only when no extra nourishment is provided are the offspring considered fully weaned.

Reproductive period: gestation + weaning (in days).

Average age at first reproduction: The age (in days) at which 75% of the female population becomes sexual mature. Many species reproduce just before or during their first winter (at approximately 80 days old), but in some species the majority of the population postpone their sexual development. Individuals are stated to have become sexual mature if they participate in mating, have been found to be pregnant or inseminated.

Observed average age: observed average age of adults in a population at a given time (in years).

Longevity: the age (in years) of the oldest observed individual. The longevity can only be obtained by marking and later recapturing individuals. Most recapture data are collected in summer roosts or hibernacula. As not all species show the same fidelity to summer roost sites or can be found in hibernacula that are accessible to humans, this measure is sensitive to the chance of recapture.

Minimum hibernation temperature: the minimum temperature (degrees Celsius) at which each species is observed.

Morphological adaptations

Length of forearm at birth: the length of the forearm (mm) of a newborn bat, measured between the elbow to the wrist of a folded wing. This is widely accepted as a measurement of size. Although it is not the best reflection of the length of an individual, it can be measured rapidly and accurately under field conditions.

Length of forearm adult: The length of the forearm (mm) of an adult bat.

Relative length of forearm of a newborn to an adult: (length of the forearm at birth*100)/ Length of forearm adult.

Wing span: the length of the wings (m). The distance between the wingtips of a bat with wings extended so the leading edge is straight (including body width).

Wing area: The combined area of the two wings (m²) including the entire tail membrane and the portion of the body between the wings.

Wing loading: the relation between body weight, wing size and gravity (Nm^-2). This measurement is related to the mean pressure on the wings. Wing loading is the weight (mass, in kg, times gravitational acceleration) divided by the wing area, i.e Wing loading = (weight adult*9.81)/ wing area. The wing load can vary significantly between geometrically similar bats. Because of such allometry, large bats have a higher wing load than smaller bats.

Wing aspect ratio: the square of the wingspan divided by the wing area, i.e. Wing aspect ratio = (wingspan)² / wing area. This ratio can be interpreted as a measure of the aerodynamic efficiency of flight. A higher aspect ratio usually corresponds with greater aerodynamic efficiency (i.e. a streamlined body) and lower energy use in flight.

Flight speed: The speed of flight (m/s). The speed of flight is usually measured in wind tunnel experiments or during radio-tracking.

Ecological adaptations

Maximum migration distance: the maximum observed distance (km) between the summer and winter habitat. In contrast to birds, the direction of migration in bats is not determined by the change of the seasons, but by the locations of the hibernacula. This migration distance can only be obtained by capturing, marking and later recapturing individuals. Bats often migrate across national boundaries and gathering recapture data requires international cooperation. The chance of recapture is sensitive to sample effort and local observation methods.

Average migration distance: the average distance (km) between the summer and winter habitat. Most species of bats migrate both short and long distances. The same restrictions described for maximum migration distance also apply to this parameter.

Echolocation type: the predominant echolocation type used by each bat species. European bats use one or sometimes a combination of the following four types of echolocations: fm-CF-fm, fm-QCF (with the QCF part dominant), FM-qcf (with the FM part dominant) and FM. For statistical reasons both FM-qcf and FM are clustered in the group FM. The FM-qcf and fm-QCF echolocations are both often loud and used to detect distant prey. FM and fm-CF-fm echolocations are softer and bats using these types of echolocation receive more detailed knowledge of their surroundings. Bats primarily use only one type of echolocation, although many can make some slight adjustments to this.

Echolocation range: the maximum distance that an echolocating bat can detect a structure or object.

Echolocation minimum frequency: the minimum echolocation frequency (MHz) used by each bat species.

Echolocation maximum frequency: the maximum echolocation frequency (MHz) used by each bat species.

Duration call (ms): the average duration (in ms) of one complete call cycle.

Distribution parameters

Northern limit of range: the most northerly observation (in latitude) of each bat species. This measurement includes anecdotal observations and observations of male bats.

Northern limit of reproduction range: the most northerly observation (in latitude) of a maternity group. Note: confusion is possible between summer roosts and maternity roosts. Summer roosts are often inhabited by both males and females and less than 70% of the adult females participate in reproduction. Maternity roosts are predominantly occupied by females, and more than 70% of the adult females participate in reproduction.

Southern limit of range: the most southerly observation (in latitude) of each bat species. This measurement includes anecdotal observations and observations of male bats.

Southern limit of reproduction range: the most southerly observation (in latitude) of a maternity group. The same restrictions described for northern limit of reproduction range also apply to this parameter.

Western limit of range: the most western observation (in longitude) of each bat species

Eastern limit of range: the most eastern observation (in longitude) of each bat species

Night length: The average night length (in hours) during midsummer (21^st June) at the northern limit of the reproduction range.

Sources: 1. Jones et al. 2009, 2. Krapp 2011, 3. Schober & Grimmberger 1997, 4. Norberg & Rayner 1987, 5. Hutterer et al. 2005, 6. Dietz et al. 2009, 7. Supplementary data from Barclay et al. 2004, 8. Wilkinson & South 2002, 9 Jones & Rydell 1994, 10. Norberg 1986, 11. Jones 1994, 12. Baagøe 1987, 13.Fleming & Eby 2003, 14. Neuweiler 2000, 15. Hayssen et al. 1993, 16. Kunz & Kurta 1987, 17. Russo & Jones 2002, 18. Brunet-Rossinni & Austad 2004, 19. Aldridge 1987, 20. Urbańczyk 1991, 21. Nagel & Nagel 1991, 22. Masing & Lutsar 2007, 23. Masing 1983, 24. Gaisler 1970, 25. Norberg 1987, 26. Baydemür & Albayrak 2006, 27. Dietz et al. 2006, 28. Sharifi 2004, 29. Kerth et al. 2001, 30. Schmidt 2005, 31. Smirnov et al. 2008, 32. Verbeek 1998, 33. Pandurkska & Beshkov 1998, 34. Harmata 1969, 35. Sachanowicz & Zub 2002, 36. Arlettaz et al. 2001, 36. Ibáñez et al. 2001, 37. Estók 2007, 38. Lohrl 1936, 39. Kunz & Hood 2000, 40. Happold & Happold 1990, 41. Rydell 1990, 42. Reiter 2004, 43. Ransome 1990, 44. Zahn 1999, 45. Deanesly & Warwick 1939, 46. Racey 1969, 47. Racey & Swift 1981, 48. Racey 1974, 49. Masing 1982, 50. Boyd & Stebbings 1989, 51. Lesiñski 1986, 52. Barak & Yom-tov 1991, 53. Arlettaz et al. 2000, 54. Gaisler et al. 1997, 55, Heise 1989, 56. Papadatou et al. 2009, 57. Unpublished data: own measurements.