Comparison of Bowl Traps With and Without Baffles
All, we are wrapping up a number of student tests from last year....here is the result of one small study...
You can see the results of these another test at the blogspot:
Test = Paired comparisons of large 1 liter white soapy water traps with and without a clear Lucite baffle that projected above the traps by approximately 20cm
Date =Summer and Fall of 2010
Locations = Fields and Lawns in Prince George's County Maryland
Number of Tests = 22
Definition of Test = Paired traps (with and without baffles) spaced 5m apart
Summary = Don't put baffles in your bowl traps
With Baffle Without Baffle
Mean: 0.86 1.91
Median: 0.5 2.0
r: 12 p(same): 0.03516
z: 1.954 p(same): 0.050742
Monte Carlo p(same): 0.05453
Interpretation of Results: While numbers of bees in each traps was rather low (mid-summer is traditionally a low bee capture time here) the results clearly demonstrate that putting in a baffle decreases the overall catch of bees by about half.
Interestingly, we ran this experiment thinking the opposite...that baffles would increase the catch as bees as bees that passed low over the traps to investigate would run into the clear panels. However, it may be the case that these panels, as they sat in the sun, were obvious to bees and they steered clear of them. This does point out that bees are impacted by the architecture of a trap's design.
Sam Droege sdroege@...
w 301-497-5840 h 301-390-7759 fax 301-497-5624
USGS Patuxent Wildlife Research Center
BARC-EAST, BLDG 308, RM 124 10300 Balt. Ave., Beltsville, MD 20705
The Early Morning
The moon on the one hand, the dawn on the other:
The moon is my sister, the dawn is my brother.
The moon on my left hand and the dawn on my right.
My brother, good morning: my sister good night.
- Hilaire Belloc.
P Bees are not optional.