Count values over a certain number in a row

Question

I read in a data frame like this:

site elevation sp1 sp2 sp3 sp4 sp5 sp6 sp7 sp8 sp9 sp10 sp11 sp12 sp13 sp14 sp15 sp16 sp17 sp18
1       1.2     0   5   2   1   2   0   1   0   2    0    1    3    0    0    0    0    0    0
2       3.9     0   4   2   0   3   0   0   0   0    2    0    2    0    0    1    0    0    0
3       4.4     0   2   1   1   2   0   1   0   0    1    0    3    0    0    0    0    0    0
4       5.5     0   4   3   0   5   0   1   0   2    1    0    3    0    0    2    0    0    0
5       9.0     0   3   2   0   1   0   1   0   2    0    0    1    0    0    0    1    0    0

sp is species number

For each site, I want to count the number of species that have 2 or more

So want to get a list like [6,6,4,7,4] or an array with the siteID and those values

I've been stuffing around with nested for loops but there's gotta be a more elegant way to do it...

Answer 1

Not the same as your output, but...

> rowSums(dat[grepl("sp",colnames(dat))]>=2)
[1] 5 5 3 6 3