Table 1 We collected data from 13 species of hibernating bats, including metabolic rate and evaporative water loss. Torpid metabolic rate (TMR) varied across temperatures (Temperature Effect column) and the range of temperatures at which the minimum torpid metabolic rate (TMRmin) was recorded varied among species. Within that range of temperatures, TMRmin did not vary among species, but species were divided into high evaporative water loss (EWL) and low EWL clusters (see Fig. 3). Values reported as mean ± standard error.

From: Interspecific variation in evaporative water loss and temperature response, but not metabolic rate, among hibernating bats

Species

n

Sites1

Body mass (g)

Range tested (°C)

Temperature effect2

TMRmin (mW g-1)

Range TMRmin (°C)

Tdefended 3 (°C)

EWL (mg H2O min-1 g-1)

EWL cluster

Vespertilionidae

Corynorhinus townsendii

152

BC1, CO, NV1, NV2, OR, UT

10.3 ± 0.1

2–10

LR3 = 13.0, p = 0.005

0.33 ± 0.03

5–8

2–5

0.009 ± 0.001

Low

Eptesicus fuscus

7

MT1

16.7 ± 1.2

2–10

LR3 = 1.6, p = 0.67

0.25 ± 0.07

2–10

 < 2

0.009 ± 0.002

Low

Lasionycteris noctivagans

23

BC2

12.7 ± 0.2

0–8

LR4 = 15.6, p = 0.004

0.15 ± 0.01

2–8

0–2

0.005 ± 0.001

Low4

Myotis californicus

45

BC2

5.7 ± 0.1

0–10

LR5 = 22.0, p < 0.001

0.26 ± 0.02

2–8

0–2

0.010 ± 0.002

Low

Myotis ciliolabrum

23

MT1, NV2

5.0 ± 0.1

2–10

LR3 = 6.2, p = 0.10

0.26 ± 0.04

2–10

 < 2

0.009 ± 0.001

Low

Myotis evotis

13

MT2

7.5 ± 0.2

2–10

LR3 = 16.7, p < 0.001

0.48 ± 0.09

5–10

2–5

0.019 ± 0.001

High

Myotis lucifugus

99

MT2, AB, NWT

8.9 ± 0.1

2–10

LR3 = 15.2, p = 0.002

0.30 ± 0.02

2–8

 < 2

0.014 ± 0.001

High

Myotis thysanodes

11

MT2

9.4 ± 0.3

2–10

LR3 = 11.2, p = 0.011

0.25 ± 0.08

5–10

2–5

0.018 ± 0.001

High

Myotis velifer

33

OK

14.4 ± 0.3

2–10

LR3 = 8.0, p = 0.046

0.25 ± 0.04

5–10

2–5

0.015 ± 0.001

High

Myotis volans

12

MT1, MT2

9.0 ± 0.2

2–10

LR3 = 10.6, p = 0.014

0.43 ± 0.08

5–10

2–5

0.015 ± 0.001

High

Myotis yumanensis

27

BC2, BC3

5.8 ± 0.1

0–8

LR4 = 48.4, p < 0.001

0.20 ± 0.01

4–6

2–4

n/a5

 

Perimyotis subflavus

34

OK

7.0 ± 0.1

2–10

LR3 = 17.1, p < 0.001

0.18 ± 0.04

8–10

5–8

0.017 ± 0.002

High

Molossidae

Tadarida brasiliensis

27

TX

13.4 ± 0.4

2–12

LR4 = 63.2, p < 0.001

0.35 ± 0.06

8–12

5–8

0.010 ± 0.001

Low

  1. 1Subscripts identify different sites in states or provinces with multiple sites.
  2. 2Effect of temperature on metabolic rate. LR = likelihood ratio with degrees of freedom indicated in subscript.
  3. 3Where metabolic rate did not increase at coldest temperature tested, Tdefended can only be determined as less than the lowest temperature tested. Otherwise Tdefended is between the range of temperatures indicated.
  4. 4L. noctivagans may represent a third cluster with lower EWL (see Fig. 3b), but to be conservative we present only two clusters here.
  5. 5EWL was not measured for Myotis yumanensis.
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