Research Question: Does the Density and detectability of Lemur change with distance?
Null model: Density and detectability are constant across the site (ie. The same on all transects)
Alternate hypothesis- density and detectability vary with transect length (and/or environmental covariates).
• Estimated Lemur density: 17 Lemurs per square kilometer with a standard error of 0.0924…
• As the 95% confidence interval spans 1.56 to 1.92, the true density of Lemur might vary from 16 to 19 deer per square kilometer
• 68% of the observations were recorded within 11.5 m of the transect and 95% within 23m
• Before truncation: The effective half strip is 14.4m for the Lemur transect. The detection probability is 30%.
• Density was below 15% beyond 20m, below 10% beyond 25m, and at 9% at 30m. Could this be due to Lemur’s behavior? Are they more used to human interaction or detection equipment?
• As lemur detection drastically decreased beyond 30m, the distance was truncated to 30m.
• After truncation: Effective half strip was 15.6m determined from the hazard rate model. The detection probability was 52%.
• Based on the AIC value, the best-fit model to assess density and detection after data truncation was the hazard rate model, the details of which are shown below.
• Unable to explore the covariates, will do so if posting assignments is still allowed.
Model Values, Detection/Density Table after truncation
nPars AIC delta AICwt cumltvWt
haz… 3 995.72 0.00 8.3e-01 0.83
hn… 2 998.88 3.16 1.7e-01 1.00
unif… 1 1301.53 305.80 3.3e-67 1.00
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