In the Zielar's case, from what I understood, there were about 2^33 kangaroos in parallel and DP = 22, N = 2^109 then:

total steps:  2*sqrt(2^109) = 2^55.5

hash table: 2^55.5 / 2^22 = 2^33.5

number of steps generated by each computing unit: 2^55.5 / 2^33 = 2^22.5, then each computing unit has generated on average 1,4 kangaroo (1,4 walk from start to the end point, DP)