CueCountingExample {Distance} | R Documentation |
Cue counts of whale blows
Description
Cues are treated as an indirect count, requiring the use of multipliers.
Format
A data.frame
with 109 rows and 15 variables.
'Region.Label stratum labels
-
Area
size (km^2) of each stratum -
Sample.Label
transect labels -
Cue.rate
rate of blows per animal per hour -
Cue.rate.SE
variability in cue rate -
Cue.rate.df
degrees of freedom (number of animals sampled for cues) -
object
object ID -
distance
perpendicular distance (km) -
Sample.Fraction
proportion of full circle scanned (radians) -
Sample.Fraction.SE
variability in sampling fraction (0) -
Search.time
Duration of scanning effort (hr) -
bss
Beaufort sea state -
sp
Species detected (all observations W in these data) -
size
Number of animals in group (all 1 in these data) -
Study.Area
study area name
Details
Because whale blows disappear instantaneously, there is no need to measure a decay rate. However a cue production rate (blows per individual per unit time) is required, as is a measure of variability of that rate.
Note
There are two other nuances in this survey. Even though the survey
is taking place on a moving ship, effort is measured as amount of time
scanning for blows. In some instances, it is not possible for the observer
to scan the sea all around them as view may be restricted by the ship's
superstructure. Here a sampling fraction
multiplier is employed to deal
with restricted vision. Units of measure of cue.rate
and Search.time
must be equal.