(a) Consent to adoption is not required of

(1) for purposes of this section, a parent who has abandoned a child for a period of at least six months;

(2) a parent of a child in the custody of another, if the parent for a period of at least one year has failed significantly without justifiable cause, including but not limited to indigency,

(A) to communicate meaningfully with the child; or

(B) to provide for the care and support of the child as required by law or judicial decree;

(3) the father of a minor if the father's consent is not required by AS 25.23.040(a)(2);

(4) a parent who has relinquished the right to consent under AS 25.23.180;

(5) a parent whose parental rights have been terminated by order of the court under AS 25.23.180(c)(2) or AS 47.10.080(c)(3);

(6) a parent judicially declared incompetent or mentally defective if the court dispenses with the parent's consent;

(7) a parent of the person to be adopted, if the person is 18 or more years of age;

(8) a guardian or custodian specified in AS 25.23.040(a)(3) or (4) who has failed to respond in writing to a request for consent for a period of 60 days or who, after examination of the guardian's or custodian's written reasons for withholding consent, is found by the court to be withholding consent unreasonably; or

(9) the spouse of the person to be adopted, if the requirement of consent to the adoption is waived by the court by reason of prolonged unexplained absence, unavailability, incapacity, or circumstances constituting an unreasonable withholding of consent.

(b) Except as provided in AS 25.23.100, notice of a hearing on a petition for adoption need not be given to a person whose consent is not required or to a person whose consent or relinquishment has been filed with the petition.