This summer...
This is what I've been doing this summer, don't expect it to be too scientific.
Basically this is a foraging study for the Oregon Silverspot larvae. There are two arena sizes, 10cm and 20cm and three treatments, all violets, no plants and mixed plants with one violet.
Foraging Observations
The mean inter-violet distances for Cascade Head, Mt. Hebo, Rock Creek and Scattercreek were surveyed. Cascade Head has a mean inter-violet distance of 27cm. Mt. Hebo, Rock Creek and Scattercreek have 12.2 cm, 10.5cm and 4.6 cm mean inter-violet distances.
The foraging study conducted has six conditions, two size and three plant treatments. 10cm and 20cm arenas with either all violet plants, no plants or a mixture of plants and one violet were used to observe the foraging behaviors of the larvae. The movement lengths and times were recorded, along with the angle of the turn.
The prediction of this experiment was to see if larvae are able to sense the presence of violets at some distance. We would expect the larvae would…
1) Find violets more often then chance.
2) Mean move lengths are longer when violets are present in order to move themselves out of the center of the arena.
3) Have a net angular displacement closer to zero when violets are present.
4) Larvae will reach the perimeter in less time when violets are present.
Expected Chance of finding violets
Larvae found violet plants more often then chance, p<.0001. In the all violet treatments, the larvae found the violets much more then expected, varying slightly between the different radius (Table 1.) In the treatments with 5 mixed plants and one violet plant, the percent expected for the larvae to find the violet was lower then expected for both treatments(table 2.)
Radius N Expectation of finding a violet by chance Observed % violet was found
10cm 16 57 93.8
20cm 13 28.6 92.3
Table 1. Expected and observed percents for finding violet plants in all violet arenas.
Radius N Expectation of finding a violet by chance Observed % violet was found
10cm 9 9.5 4.5
20cm 9 4.7 0
Table 2. Expected and observed percents for finding violet plants in mixed plant arenas.
Move Length
Mean move lengths were calculated for each successful trial. When combining both perimeter sizes, mixed plant treatment has the greatest trend towards long mean move length (Figure 1.) The mean move length for 10cm arena shows no trend for any treatment (Figure 2.) The mean move length for 20cm indicates a trend with the mixed plant treatment (Figure 3.)
Net Angular Displacement
To calculate the net angular displacement of the larvae, all left angles were considered negitive and all right angles were considered positive. The angles were added up, and then the absolute value of that sum was used for NAD. In instances where violets were present in 10cm arenas, there appears to be no relationship between that presence and the absolute NAD (95.2 & 79.1.) There appears to be a trend in the 20cm treatments when violets are present, but the sample size (N = 22 & 5) is too small for statistical significance (71.4 & 243.2.)
To calculate the absolute NAD for each turn, all left and right turns were considered positive. The sum of those numbers were added up and used for the absolute NAD. In the instances where violets were present in 10cm arenas, there appears to be little or no relationship (Figure 4, 137.3 & 203.8.) There appears to be a trend in the 20cm arenas, but the sample size (N = 22 & 5) if too small for statistical significance (Figure 5, 295.1 & 121.2.)
Its so much shorter without the figures and tables. Alas, I am not smart enough, nor thrilled enough to figure out how to enter them. Just use your imagination :)
Basically this is a foraging study for the Oregon Silverspot larvae. There are two arena sizes, 10cm and 20cm and three treatments, all violets, no plants and mixed plants with one violet.
Foraging Observations
The mean inter-violet distances for Cascade Head, Mt. Hebo, Rock Creek and Scattercreek were surveyed. Cascade Head has a mean inter-violet distance of 27cm. Mt. Hebo, Rock Creek and Scattercreek have 12.2 cm, 10.5cm and 4.6 cm mean inter-violet distances.
The foraging study conducted has six conditions, two size and three plant treatments. 10cm and 20cm arenas with either all violet plants, no plants or a mixture of plants and one violet were used to observe the foraging behaviors of the larvae. The movement lengths and times were recorded, along with the angle of the turn.
The prediction of this experiment was to see if larvae are able to sense the presence of violets at some distance. We would expect the larvae would…
1) Find violets more often then chance.
2) Mean move lengths are longer when violets are present in order to move themselves out of the center of the arena.
3) Have a net angular displacement closer to zero when violets are present.
4) Larvae will reach the perimeter in less time when violets are present.
Expected Chance of finding violets
Larvae found violet plants more often then chance, p<.0001. In the all violet treatments, the larvae found the violets much more then expected, varying slightly between the different radius (Table 1.) In the treatments with 5 mixed plants and one violet plant, the percent expected for the larvae to find the violet was lower then expected for both treatments(table 2.)
Radius N Expectation of finding a violet by chance Observed % violet was found
10cm 16 57 93.8
20cm 13 28.6 92.3
Table 1. Expected and observed percents for finding violet plants in all violet arenas.
Radius N Expectation of finding a violet by chance Observed % violet was found
10cm 9 9.5 4.5
20cm 9 4.7 0
Table 2. Expected and observed percents for finding violet plants in mixed plant arenas.
Move Length
Mean move lengths were calculated for each successful trial. When combining both perimeter sizes, mixed plant treatment has the greatest trend towards long mean move length (Figure 1.) The mean move length for 10cm arena shows no trend for any treatment (Figure 2.) The mean move length for 20cm indicates a trend with the mixed plant treatment (Figure 3.)
Net Angular Displacement
To calculate the net angular displacement of the larvae, all left angles were considered negitive and all right angles were considered positive. The angles were added up, and then the absolute value of that sum was used for NAD. In instances where violets were present in 10cm arenas, there appears to be no relationship between that presence and the absolute NAD (95.2 & 79.1.) There appears to be a trend in the 20cm treatments when violets are present, but the sample size (N = 22 & 5) is too small for statistical significance (71.4 & 243.2.)
To calculate the absolute NAD for each turn, all left and right turns were considered positive. The sum of those numbers were added up and used for the absolute NAD. In the instances where violets were present in 10cm arenas, there appears to be little or no relationship (Figure 4, 137.3 & 203.8.) There appears to be a trend in the 20cm arenas, but the sample size (N = 22 & 5) if too small for statistical significance (Figure 5, 295.1 & 121.2.)
Its so much shorter without the figures and tables. Alas, I am not smart enough, nor thrilled enough to figure out how to enter them. Just use your imagination :)