Sea Turtle Nesting Habits in R

I pulled together a small and simple data set to have a look at turtle nesting on South Florida’s beaches, and to see if it had any relationships to some easy-to-find socioeconomic data. I looked at nesting habits for greens, loggerheads, and leatherbacks to see if you could create linear regressions with population by county, median household income, number of households by county, and per capita income by county.

The highest correlation I got was between leatherback nests and per capita income, but it bore no statistically significant relationship upon running the regression. I put my R code here with comments for people like me who are learning to play around in R.

R Code

loggerhead.nest <- sea.turtle.nests$C..carettaNEST
loggerhead.emergence <- sea.turtle.nests$C..carettaNON.NESTING.EMERGENCE
green.nest <- sea.turtle.nests$C..mydasNEST
green.emergence <- sea.turtle.nests$C..mydasNON.NESTING.EMERGENCE
leather.nest <- sea.turtle.nests$D..coriaceaNEST
leather.emergence <- sea.turtle.nests$D..coriaceaNON.NESTING.EMERGENCE
#make latin to common name labeling
plot(loggerhead.nest ~ population , data=sea.turtle.nests)
plot(loggerhead.nest ~ log(population) , data=sea.turtle.nests)
#population alone looked off, took the log
plot(green.nest ~ log(population) , data=sea.turtle.nests)
plot(leather.nest ~ log(population) , data=sea.turtle.nests)
#took plots for all three species
cor(loggerhead.nest,sea.turtle.nests$population)
#0.03736234
cor(loggerhead.nest,sea.turtle.nests$per.capita.income)
#0.2318836
cor(loggerhead.nest,sea.turtle.nests$median.household.income)
#-0.04984773
cor(green.nest,sea.turtle.nests$population)
#0.007499322
cor(green.nest,sea.turtle.nests$per.capita.income)
#0.2130996
cor(leather.nest,sea.turtle.nests$population)
#0.01959502
cor(leather.nest,sea.turtle.nests$per.capita.income)
#0.4036139
leather.lm <- lm(leather.nest ~ sea.turtle.nests$per.capita.income , data=sea.turtle.nests)
summary(leather.lm)
#Coefficients:
#Estimate Std. Error t value Pr(>|t|)
#(Intercept) -2.083e+02 2.397e+02 -0.869 0.403
#sea.turtle.nests$per.capita.income 1.227e-02 8.385e-03 1.463 0.171
#p-value: 0.1714
#Adjusted R-squared: 0.0868

Figure 1: leatherback nests and log of population: no linear relationship

Image

Figure 2 Loggerhead nest and log population

Image

Figure 3 Green nests and log population

Rplot3

Getting better data to reflect development along the ocean front would probably help here, also looking at nesting habits through time .

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