Oregon Revised Statutes Domestic Relations § 109.145

If a respondent fails to answer or fails to appear at trial, the court shall have the power to proceed accordingly. In such case, the court may make a determination of paternity and may impose such obligations on the respondent as it deems reasonable. In all such cases corroborating evidence in addition to the testimony of the parent or expectant parent shall be required to establish paternity and the court may, in its discretion, order such investigation or the production of such evidence as it deems appropriate to establish a proper basis for relief. The testimony of the parent or expectant parent and the corroborating evidence may be presented by affidavit.