Dog overpopulation and diagnosis of intestinal parasites on Santa Cruz Island, Galapagos 2016

Dog overpopulation on Santa Cruz Island, Galapagos 2018

“…In 2015, the estimated human population was 15,701 (about 12,213 people distributed on 16 neighborhoods and 2,468 households in the urban parish of Puerto Ayora and 3,488 people in the two rural neighborhoods of Bellavista and Santa Rosa) (Ecuador's Instituto Nacional de Estadística y Censos, 2015). Santa Cruz was selected for this study to measure and compare HD ratio estimates between 2014 (6.1:1) (Diaz et al, 2016), 2016 (4.7:1) (Diaz et al, 2018) and 2018.…”

“…This study targeted the same urban neighborhoods and blocks and rural neighborhoods included in dog surveys conducted on Santa Cruz Island in September 2014 (Diaz et al, 2016) and September 2016 (Diaz et al, 2018). Briefly, eight of 16 urban neighborhoods and one to four blocks within each selected neighborhood were randomly selected.…”

“…The 2016 population growth agent‐based model (Diaz et al 2018) was updated using new dog demographic data collected in 2018. The general structure is the same as that presented by Diaz et al (2018) and Yoak et al (2016). Broadly, an agent‐based model was constructed in which dogs bred and died at local estimated rates, and a sterilization control scheme was overlaid to assess impacts.…”

“…In the past, observational studies concluded that feral dogs can prey on marine iguanas on the Galapagos (Kruuk and Snell, 1981). Furthermore, the risk of potential outbreaks of CDV in dogs on the Galapagos (which can potentially spill over to marine mammals and cause mortality) is not negligible (Diaz et al, 2016; Diaz et al, 2018). In 2001, an outbreak of CDV killed more than 600 dogs on Santa Cruz and Isabela Islands, Galapagos (Levy et al, 2008).…”

“…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.…”