This project contains five datasets which are reported in "Understanding metrics of stress in the context of invasion history: the case of the brown treesnake (Boiga irregularis)". Overall, this dataset describes metrics of individual and demographic stress (baseline and 1 hour post-capture corticosterone, body condition, and bacterial killing ability) in the invasive snake Boiga irregularis on Guam collected in intervals of 10-15 years from 1992 to 2018. It also contains corticosterone values obtained from different methods of measuring hormones ( radioimmunoassay; RIA versus enzyme immunoassay; EIA) for 2018 data. The first dataset is from the file "boiga_18cort_method.csv", which contains baseline and 1 hour-after-capture blood plasma corticosterone values measured with two methods (enzyme immunoassay and radioimmunoassay) from Boiga irregularis captured on Guam in 2018. This dataset is used in Model 1 of the publication. The second dataset "boiga_bodycond_submit.csv" contains morphometric data for Boiga irregularis captured on Guam in 1991-1993, 2003, and 2018. The dataset is used to calculate the body condition index used throughout the publication. The third dataset is from the file "boiga_all_baseline_submit.csv", which contains baseline blood plasma corticosterone values, basic morphometrics, body condition, and capture information for Boiga irregularis on Guam from 1992-2018. Corticosterone from 2018 is reported for two methods: radioimmunoassay and enzyme immunoassay. This dataset is used for models 2 and 3 of the publication. The fourth dataset is from the file "boiga_base_1h_submit.csv", which contains baseline and 1-hour-after-capture blood plasma corticosterone data for Boiga irregularis captured on Guam in 2003 and 2018. The dataset also includes capture data, morphometrics, and body condition for the animals. This dataset is used for model 4 of the publication. The fifth and final dataset is "boiga_bacterialkilling_submit.csv", which reports the baseline and 1-hour-after-capture blood plasma corticosterone and bacterial killing ability (measured as the plasma dilution at which 50% of bacteria was killed). This dataset was used in model 5 of the publication.