Table 5.

Temperatures of five brood cells (indexed from a to e) in relation to the number of long-lasting cell visitors (Nvisitors) in the adjacent cells (setup D)

Nvisitors
Cell Total time 0 1 2 3 4 5 6
a100%0%21.9%51.3%25.6%1.3%0%
35.1±0.3°C34.9±0.2°C35.0±0.2°C35.4±0.2°C35.4±0.0°C
b100%0%12.0%34.3%35.7%15.0%3.1%0%
35.0±0.5°C34.2±0.2°C34.8±0.3°C35.3±0.3°C35.7±0.1°C35.8±0.1°C
c100%3.6%20.8%39.4%22.2%6.4%7.5%0%
34.2±0.4°C33.9±0.1°C34.0±0.3°C34.2±0.4°C34.2±0.3°C34.2±0.3°C34.5±0.4°C
d100%14.7%13.3%46.8%21.4%3.7%
34.2±0.4°C33.8±0.2°C33.9±0.4°C34.2±0.4°C34.4±0.3°C35.0±0.2°C
e100%5.2%24.4%55.6%13.4%1.4%0%0%
33.6±0.6°C32.9±0.1°C33.3±0.3°C33.7±0.5°C34.3±0.3°C34.9±0.0°C
  • The number of empty cells adjacent to a certain sealed brood cell was 6 for cells b, c and e. Cells a and d were surrounded by 5 or 4 empty cells and 1 or 2 non-visitable sealed brood cells, respectively. The % values are the times during which a certain number of cell visitors were present (% of the total observation time of 180 min). Brood cell temperatures (mean ± S.D.) are given separately for elongated periods (>1.5 min) with a constant number of Nvisitors and for the total observation time, irrespective of Nvisitors. The increase of brood temperature with the number of cell visitors was significant (Jonckheere's trend test, P<0.001 for each of the five brood cells). Sample sizes of the classified temperatures (0—6) are N=506, 447 and 448 (cells a, b and c) and N=7672 and 8686 values (cells d and e; see text for the sampling rates), respectively. Thive=32.3±0.6°C (air temperature in the brood nest); Troom=26.0±0.7°C.