“…In September 2014, the observed human:dog (HD) ratio on Santa Cruz Island was 6.14:1, which extrapolated to 2,503 dogs (Diaz et al, 2016). In September 2016, the observed HD ratio on Santa Cruz was 4.77:1 (3,290 dogs) (Diaz et al, 2018); an increase of 31% in the dog population from 2014 to 2016. In that study, using dog population's demographics on Santa Cruz from 2014 and 2016, a decline in the dog population below baseline levels (i.e., 3,290 dogs in 2016) was estimated to occur 5 years after, if 500 dogs that underwent surgery every year were females.…”