Counting polygons in shapefile - r

Question

So I have multiple species ranges which look like the following (colored blue for example) This one runs east to west across Africa:
I can get the total area by using gArea in the rgeos package. What I want to know is how many individual polygons make up this file - i.e. how many distinct regions are there to the total range (this could be islands, or just separated populations) and what the ranges of those polygons are. I have been using the following code:
#Load example shapefile
shp <- readShapeSpatial("species1.shp")
#How many polygon slots are there?
length(shp#polygons)
>2
#How many polygons are in each slot
length(shp#polygons[[1]]#Polygons
length(shp#polygons[[2]]#Polygons
and to get the area of a particular one:
shp#polygons[[1]]#Polygons[[1]]#area
Is this correct? I'm worried that a lake in the middle of the range might constitute a polygon on its own? I want to end up with a list that is roughly like:
Species A Species B
Polygon 1 12 11
Polygon 2 13 10
Polygon 2 14 NA
If I wanted to compile a list for every species of how many polygons and their individual ranges would be pretty straightforward to pass to a loop if the above code is correct.
Thanks

Answer 1

This is a very un-glamorous solution, but it gets the job done at the moment.
for(i in 1:length(shpfiles)){
shp <- shpfiles[[i]]
#1) Create master list of all polygon files within a shapefile
#How many lists of polygons are there within the shpfile
num.polygon.lists <- length(shp#polygons)
#Get all polygon files
master <- vector(mode="list")
for(i in 1:num.polygon.lists){
m <- shp#polygons[[i]]#Polygons
master[[i]] <- m
}
#Combine polygon files into a single list
len <- length(master)
if(len > 1) {
root <- master[[1]]
for(i in 2:length(master)){
root <- c(master[[i]], root)}
} else {root <- master[[1]]}
#Rename
polygon.files <- root
#2) Count number of polygon files that are not holes
#Create a matrix for the total number of polygon slots that are going to be counted
res <- matrix(NA,ncol=1 , nrow=length(polygon.files))
#Loop through polygons returning whether slot "hole" is TRUE/FALSE
for(i in 1:length(polygon.files)){
r <- isTRUE(polygon.files[[i]]#hole)
res[[i,1]] <- r
}
#Count number times "FALSE" appears - means polygon is not a hole
p.count <- table(res)["FALSE"]
p.count <- as.numeric(p.count)
print(p.count)
}
It's a start

Answer 2

I used the following code to find out how many multipart polygons there were in each "row" of a shapefile...
sapply(shapefile#polygons, function(p) length(p#Polygons))