Opinion

We are asked to determine whether the trial court erred in terminating a natural father’s parental rights by considering only *68 the best interests of the child without first considering whether an award of custody to him would be detrimental to the child. We conclude Civil Code section 4600 1 is applicable to all section 7017, subdivision (d) termination proceedings and reverse the judgment.

I

Edward and Baby Girl M.’s mother dated during the fall of 1980. When the relationship ended in November, neither of them knew she was pregnant. Baby Girl M. was born on July 18, 1981. While in the hospital, the mother requested adoption assistance, met with a social worker, and placed the child in a foster home three days later. She had never informed Edward of the pregnancy and did not tell him of the birth until August 1, 1981.

Edward immediately contacted the San Diego Department of Social Welfare to determine his rights. He met with a social worker on August 5 and requested his daughter be placed with the family who was then providing day care for his sons. Later that day the mother formally relinquished the child for adoption and rejected Edward’s placement request, stating she wished the child placed with a family neither of them knew.

On August id a section 7017 petition to terminate Edward’s parental rights was filed. That same day Edward again met with the social worker, discovered the mother had relinquished the child for adoption, and expressed his fear he would be unable to see his child. He arranged to visit the child at the agency offices on August 17, at which time he specifically requested custody. Despite the father’s wishes, Baby Girl M. was placed with the prospective adoptive parents on August 24.

At the section 7017 hearing in December, the court found Edward to be the biological father and “a good parent [who] can provide a good, loving home for this child.” However, the court determined it was in the child’s best interests to remain with the adoptive parents. Edward’s parental rights were terminated without a finding it would be detrimental to the child to award him custody.

II

In 1976 the Uniform Parentage Act was enacted. (§§ 7000-7021.) One of its primary purposes, as well as that of several related statutes enacted simultaneously, was to eliminate the distinctions between legitimate and illegitimate children. To this end, the act declares the parent-child relation *69 ship extends to every child and every parent, regardless of the marital status of the parents (§ 7002), and sets forth various procedures by which the relationship of parent and child may be established. (§§ 7006, 7015.) In addition, it gives the natural father a right he did not previously possess: the right to notice of the hearing to terminate his parental rights. (§ 7017, subds. (b), (d), (f).)

No adoption may be completed, even after a mother has relinquished the child, until a section 7017 2 petition is granted terminating the natural father’s rights. Absent his prior written waiver, he is entitled to notice of the hearing. If he appears and “claims custodial rights, the court shall proceed to determine . . . custodial rights ....”(§ 7017, subd. (d), italics added.)

The Legislature, however, when it enacted sections 7000 et seq., did not specify the standard to be employed in a section 7017, subdivision (d) proceeding. Our analysis of statutory and decisional authority, recent legislative history, and public policy leads us to conclude the section 4600 detriment standard applies to a section 7017 custody hearing.

Section 4600 3 was enacted in 1969 as part of the Family Law Act. It sets forth a mandate that custody of a child in a dissolution proceeding could *70 not be awarded to nonparents without both parents’ consent or a finding “that an award of custody to a parent would be detrimental to the child. >>

In In re B. G. (1974) 11 Cal.3d 679 [ 114 Cal.Rptr. 444 , 523 P.2d 244 ], this court analyzed the legislative history of section 4600 and concluded “[a]s enacted, section 4600 expressly recognizes that custody should be awarded to parents in preference to nonparents. As between parents, it permits the court to award custody ‘according to the best interests of the child,’ but in a dispute between a parent and a nonparent, the section imposes the additional stipulation that an award to the nonparent requires a finding that ‘an award of custody to a parent would be detrimental to the child.’ ” (Id., at p. 698.) “There can be no question of the desirability of a uniform rule; the Legislature’s specification that section 4600 applies to ‘any proceeding where there is at issue the custody of a minor child’’ demonstrates that section 4600 was enacted to fulfill that objective.” (Id., at p. 696, fns. omitted, italics added.)

The court in In re Reyna (1976) 55 Cal.App.3d 288 [ 126 Cal.Rptr. 138 ], relying on In re B. G., applied the section 4600 standard to facts similar to ours. An unwed father sought custody of his infant son after the mother relinquished the child for adoption. The court held “[b]ecause David asserts his entitlement to the physical custody of his child against the agency’s claim to custody based on the mother’s relinquishment, [section 4600] clearly applies.” (Id., at p. 296.)

The Second District Court of Appeal recently decided In re Adoption of Baby Boy D. (1984) 159 Cal.App.3d 8 [ 205 Cal.Rptr. 361 ], When a motion was made to terminate his parental rights, the unwed father sought custody. The court noted the issue was custody, not adoption. “So long as [the mother] does not assert her mother’s right to physical custody, [the natural father] may not be denied custody of his child or have his parental rights terminated except upon finding that leaving custody with [the adoptive parents] is necessary to avert harm to the child.” (Id., at p. 22.)

The Legislature, when it enacted section 7017, was aware of this court’s decision in In re B. G. extending the section 4600 standard to proceedings outside the Family Law Act. If the Legislature did not wish the detriment standard to apply to section 7017, subdivision (d) custody proceedings, it *71 could have so indicated. (In re William Phyle (1947) 30 Cal.2d 838 [ 186 P.2d 134 ], Estate of Carson (1959) 174 Cal.App.2d 291 [ 344 P.2d 612 ], Estate of Fritz (1951) 102 Cal.App.2d 385 [ 227 P.2d 539 ].)

We are aware of the Legislature’s enactment of Assembly Bill No. 649, vetoed by the Governor because he objected to certain financial provisions. Reintroduced as Assembly Bill No. 1782, and amended on January 17, 1984, the proposed statute again declared section 4600’s parental preference would not apply to an alleged natural father seeking custody in a section 7017 hearing. However, this provision, as shown by a report on the bill to the Senate Committee on the Judiciary, was never considered by the Assembly Judiciary Committee, either as originally enacted or as reintroduced. The report stated: “AB 649 (McAlister) of 1983 contained a provision, identical to the one in AB 1782, applying the parental preference only to the presumed natural fathers. [S] This provision was amended into both bills after they had left the Assembly Judiciary Committee. Thus it is once again being considered by only one policy committee, [f] AB 649, which passed Senate Judiciary on a vote of 9-1, was heard when almost 80 other bills were on calendar.” The report continues: “On November 18, the Select Committee on Children and Youth held an interim hearing on alleged and presumed fathers. This hearing was well attended by representatives from the Department of Social Services, adoption agencies, the academic community, and those interested in fathers’ rights. [f] The consensus of the witnesses was that the rights of alleged fathers are important and should be protected, [f] This bill is contrary to that consensus. ” (Italics added.)

In a similar report on the bill, as amended February 23, 1984, the Senate Committee on the Judiciary confirmed the Legislature did not intend to deprive alleged natural fathers of the parental preference of Civil Code section 4600—“After lengthy debate the subject matter of this provision [denying alleged fathers section 4600 protection] was sent to interim, and the author agreed to amend it out of the bill. ” (Italics added.) Thus the Legislature has declined its opportunity to disprove application of the section 4600 standard to section 7017 hearings.

Our interpretation is also consistent with the public policy which led to the Uniform Parentage Act and other relevant civil code sections. Sections 221-230 set forth the mechanisms for adoption. Sections 232-240 contain the applicable law on freeing a minor from parental custody and control. Read together with the Uniform Parentage Act, the following statutory scheme emerges.

Under section 197, both mothers and presumed fathers 4 are entitled to custody of their minor children. An adoption can proceed only if their con *72 sent has been given or their parental rights have been terminated pursuant to a section 232 or section 224 hearing. The mother and presumed father are equally entitled to the child’s custody; therefore his consent is necessary before the child may be adopted.

However, if the father is merely a natural father 5 and not a presumed father, the mother alone is entitled to the child’s custody. Only when the natural mother relinquishes the child for adoption do the natural father’s rights commence. (§ 7017, subd. (d).) He is to be notified and his custodial rights, if claimed, determined before the adoption can proceed.

The Legislature intended to differentiate between the veto powers accorded unwed mothers and presumed fathers on the one hand and natural fathers on the other. Application of the detriment standard does not defeat this policy. We do not find W. E. J. v. Superior Court (1979) 100 Cal.App.3d 303 [ 160 Cal.Rptr. 862 ] to the contrary. W. E. J. recognizes “. . . that, although the father was not a presumed father,” he nevertheless was entitled to a hearing to determine his custodial rights. (Id., at p..311.) Confusion arose when the court seemed to reject a detriment standard by inferring its use would be tantamount to a veto. We agree the natural father, unlike the presumed father, holds no automatic veto power over the adoption. It does not follow, however, that the use of the detriment standard would lead to such a veto power and we disapprove any language in W. E. J. to the contrary. 6 In the context of section 7017, the mother must *73 relinquish the child for adoption before the natural father has any rights. And once the child has been relinquished, we can foresee many instances where the trial court could find it was not only in the best interests of the child to terminate the father’s parental rights, but it would be detrimental to the child not to do so. Then, as the natural and not the presumed father, his consent would be unnecessary and the adoption could proceed.

Ill

The major United States Supreme Court cases addressing cognizable interests of unwed fathers have involved situations where the fathers assumed full custodial responsibility or failed to pursue possibilities available to them. They either voluntarily ignored their rights or were precluded from ever exercising full custodial control because the mother had not relinquished the child. Both Stanley v. Illinois (1972) 405 U.S. 645 [ 31 L.Ed.2d 551 , 92 S.Ct. 1208 ] 7 and Caban v. Mohammed (1979) 441 U.S. 380 [ 60 L.Ed.2d 297 , 99 S.Ct. 1760 ] 8 involved biological fathers who had established strong ties with the children and held them out as their own. Both would qualify in California as presumed fathers, entitled to custody. Both had taken the affirmative steps necessary to assume parental responsibilities. By contrast, in Quilloin v. Walcott (1978) 434 U.S. 246 [ 54 L.Ed.2d 511 , 98 S.Ct. 549 ], 9 the father did not live with the child, offered only sporadic *74 support, and made no attempt to legitimate the child until it was 11 years old, when adoption was sought by the mother’s husband. The court denied the legitimation petition by the natural father, who had declined to accept parental responsibility for 11 years and failed to avail himself of his statutory right to do so, on the ground of the best interests of the child. He had not requested custody. Under these circumstances, it is not difficult to assume the court could have also found it detrimental to the child to place her with the natural father. Additionally, in Quilloin , the mother retained custody and merely consented to her new husband’s adoption request. Thus, no question arose of transferring custody from the only remaining parent.

Similarly, in Lehr v. Robertson (1983) 463 U.S. 248 [ 77 L.Ed.2d 614 , 103 S.Ct. 2985 ], 10 the mother remarried and the new husband sought to adopt. The biological father was not given notice of the adoption proceedings because he had not strictly complied with New York law by filing a claim with the putative father registry. Again, a statutory method of establishing a parent-child relationship was available but he took no action to utilize it.

The Supreme Court has not directly considered a fact situation similar to ours, where a mother has relinquished a newborn child and refused the father any contact. Thus the court has not addressed whether the natural father’s parental rights may be terminated by only a best interests standard, or if a further finding of detriment is required.

We recognize our state scheme satisfies the procedural requirements of notice and opportunity to be heard. Thus, our holding is not based on any lack of federal due process. However, it is appropriate to note a recent law review article exploring the constitutional rights of unwed fathers. “Recognition of an opportunity interest in unwed fathers requires a conclusion that if the two elements of a constitutionally protected parent-child relationship are the biological link and commitment to and exercise of custodial responsibility, the state may not deny biological parents the opportunity to establish a protected custodial relationship.” (Buchanan, The Constitutional Rights of Unwed Fathers Before and After Lehr v. Robertson (1984) 45 Ohio State L.J. 313, 351.) This “opportunity interest” may, however, be lost where a parent voluntarily fails to pursue custodial responsibility or “the child’s stepfather voluntarily assumes full custodial responsibility for the *75 child.” (Id., at p. 368.) 11 The fitness or detriment standard is met in the first instance by effective abandonment; in the second, the father will never have an opportunity to seek custody.

However, in the absence of these factors, and where an adoption is sought by “strangers, the father’s opportunity to establish a protected relationship must prevail in the absence of his unfitness.” (Id., at p. 373.)

IV

We have held section 4600 applies to all parental custody proceedings involving a minor child. (In re B. G., supra, 11 Cal.3d 679 .) Whether it now applies in section 7017 hearings should not be controlled by the context in which insemination occurs. The actions of both parents after the birth of their child determine their ability to accept parental responsibility. An unwed mother may have had no more desire to conceive or knowledge of the conception than the unwed father. Nevertheless she is given a choice to keep or relinquish the child because she gave birth. Her decision to release the child for adoption should not deprive the father of a meaningful opportunity to retain and develop his relationship.

A natural father may not have initial custodial or veto rights equal to those of a presumed father. However, both classes of fathers share the same burdens of support for the child and liability for the reasonable expenses of the mother’s pregnancy and confinement. (§§ 7010 and 7012.) Thus when the natural father’s rights do arise, upon relinquishment by the mother, and he claims custody at a section 7017 hearing, an additional finding of detriment is necessary to terminate his parental rights.

V

We have held the trial court erred by applying the best-interests-of-the-child standard without first determining whether granting custody to the natural father would be detrimental. A review of the evidence introduced at the hearing indicates a finding of detriment would have been unsupportable at that time. However, concerned, as we must be, with the child’s welfare *76 and because of the passage of time, we recognize further evidence will be necessary. 12 The circumstances leading to the earlier determination should be reviewed in light of subsequent events. “[W]e recognize that during the pendency of this appeal, additional circumstances bearing on the best interests of the child(ren) herein may have developed. Any such circumstances may, of course, be considered by the trial court on remand.” (In re Marriage of Carney (1979) 24 Cal.3d 725, 741 [ 157 Cal.Rptr. 383 , 598 P.2d 36 , 3 A.L.R. 4th 1028 ].)

We emphasize the section 7017 hearing is ancillary to the adoption, and while a condition precedent, it is not determinative. Adoptions can only be concluded after completion of the termination hearings and custody cannot, therefore, be determined by comparing the adoptive family and the father.

The judgment terminating the father’s custodial rights is reversed. The matter is remanded to the trial court for further proceedings consistent with this opinion.

Bird, C. J., Broussard, J., Reynoso, J., and Grodin, J., concurred.

Assigned by the Chairperson of the Judicial Council.

All references are to the Civil Code unless otherwise indicated.

Section 7017 provides in part: “(a)(1) If a mother relinquishes for or consents to or proposes to relinquish for or consent to the adoption of a child who has (1) a presumed father under subdivision (a) of Section 7004 . . . the father shall be given notice of the adoption proceeding and have the rights provided under Chapter 2 (commencing with Section 221), Title 2, Part 3, Division 1 of the Civil Code, . . . [f] (b) If a mother relinquishes for, consents to, or proposes to relinquish for or consent to the adoption of a child who does not have (1) a presumed father under subdivision (a) of Section 7004 ... the agency or person to whom the child has been or is to be relinquished, or the mother or the person having custody of the child, shall file a petition in the superior court to terminate the parental rights of the father, unless the father’s relationship to the child has been previously terminated or determined not to exist by a court, or unless the father has been served as prescribed in subdivision (f) with a written notice alleging that he is or could be the natural father of the child to be adopted or placed for adoption and has failed to bring an action for the purpose of declaring the existence of the father and child relationship pursuant to subdivision (c) of Section 7006 within 30 days of service of such notice or the birth of the child, whichever is later . . . . [K] (d) If, after the inquiry, the natural father is identified to the satisfaction of the court, or if more than one man is identified as a possible father, each shall be given notice of the proceeding in accordance with subdivision (f), ... If any of them fails to appear or, if appearing, fails to claim custodial rights, his parental rights with reference to the child shall be terminated. If the natural father or a man representing himself to be the natural father, claims custodial rights, the court shall proceed to determine parentage and custodial rights in whatever order the court deems proper. If the court finds that the man representing himself to be the natural father is a presumed father under subdivision (a) of Section 7004, then the court shall issue an order providing that the father’s consent shall be required for an adoption of the child. In all other cases, the court shall issue an order providing that only the mother’s consent shall be required for the adoption of the child.”

Civil Code section 4600, subdivisions (a) and (c) provide in pertinent part “In any proceeding where there is at issue the custody of a minor child, the court may.....make *70 such order for the custody of the child during minority as may seem necessary or proper, [f] Before the court makes any order awarding custody to a person or persons other than a parent, without the consent of the parents, it shall make a finding that an award of custody to a parent would be detrimental to the child and the award to a nonparent is required to serve the best interests of the child. ...” (Italics added.)

Section 7004 provides in part: “(a) A man is presumed to be the natural father of a child if he meets the conditions as set forth in Section 621 of the Evidence Code or in any of the *72 following subdivisions: [t] (1) He and the child’s natural mother are or have been married to each other and the child is born during the marriage, or within 300 days after the marriage is terminated by death, annulment, declaration of invalidity, or divorce, or after a decree of separation is entered by a court. [H] (2) Before the child’s birth, he and the child’s natural mother have attempted to marry each other by a marriage solemnized in apparent compliance with law, although the attempted marriage is or could be declared invalid, and, [K] (i) If the attempted marriage could be declared invalid only by a court, the child is born during the attempted marriage, or within 300 days after its termination by death, annulment, declaration of invalidity, or divorce; or [1] (ii) If the attempted márriage is invalid without a court order, the child is born within 300 days after the termination of cohabitation. [H] (3) After the child’s birth, he and the child’s natural mother have married, or attempted to marry, each other by a marriage solemnized in apparent compliance with law, although the attempted marriage is or could be declared invalid, and [H] (i) With his consent, he is named as the child’s father on the child’s birth certificate, or [H] (ii) He is obligated to support the child under a written voluntary promise or by court order. [U] (4) He receives the child into his home and openly holds out the child as his natural child. ”

A natural father is one who has been found to be the biological father but not a presumed father.

We note an additional problem with applying W. E. J. in the present context. The hearing below in W. E. J. was an adoption proceeding, not a section 7017 hearing. As a result, its author was concerned because there was “no finding that the change of custody [from the prospective adoptive parents] was in the child’s best interest.” (Id., at pp. 306-307.) But the concerns voiced by the other justices illustrate there was no consensus on the appropriate standard to be applied. The dissent strongly supported application of the detriment standard enunciated in In re B. G., supra, 11 Cal.3d 679 . The concurring opinion stated, “The trial *73 court is directed (as it has not yet done) to consider, whether it will be adverse to the best interests of the child to give custody to the father.” (Id., at p. 315.)

In Stanley , the court concluded, “as a matter of due process,” a father’s parental rights could not be terminated without notice and “a hearing on his fitness as a parent. . . .” (Id., at p. 649 [ 31 L.Ed.2d at p. 557 ].) The Stanley court held unconstitutional a statutory scheme which irrebuttably presumed all unwed fathers unfit.

The court in Caban found a statute allowing unwed mothers, but not unwed fathers, to prevent adoptions, to be unconstitutional. The court concluded “this undifferentiated distinction between unwed mothers and unwed fathers, applicable in all circumstances where adoption of a child of theirs is at issue, does not bear a substantial relationship to the State’s asserted interests.” (Id., at p. 394 [ 60 L.Ed.2d at p. 308 ].) The court found no “profound difference between the affection and concern of mothers and fathers for their children” (id., at p. 392) and indicated “no showing” was made that allowing natural fathers the right to consent would “pose a strong impediment for adoption.” (Id., at p. 392 [ 60 L.Ed.2d at p. 307 ].)

The Caban court, however, in two footnotes, specifically limited the application of its holding. In footnote 11, the court acknowledged the question of newborns was not at issue and reserved judgment. In footnote 16, the court stated: “Because we have ruled that the New York statute is unconstitutional under the Equal Protection Clause, we similarly express no view as to whether a State is constitutionally barred from ordering adoption in the absence of a determination that the parent whose rights are being terminated is unfit.” (Id., at p. 394 [ 60 L.Ed.2d at p. 308 ].)

A “father’s interest in the ‘companionship, care, custody, and management’ of his children is ‘cognizable and substantial,’ [citation] and ... the State’s interest in caring for the children is ‘de minimis’ if the father is in fact a fit parent [citation], Stanley left unresolved the degree of protection a State must afford to the rights of an unwed father ... in which the countervailing interests are more substantial.” (Quilloin v. Walcott, supra, 434 U.S. 246, 248 [ 54 L.Ed.2d 511, 515 ].)

In Lehr , the court found constitutional a statutory scheme requiring an unwed father to file a notice with a registry claiming paternity of a child born out of wedlock if he was to be entitled to notice of adoption proceedings. But again the court did not rule on the issue with which we are presented.

In Adoption of Rebecca B. (1977) 68 Cal.App.3d 193, 198 [ 137 Cal.Rptr. 100 ], the court held only the mother’s consent necessary for a stepparent adoption but found “. . . there inhere in the natural father certain residual rights in the child which cannot be terminated by adoption [citation] without notice and the opportunity to be heard. Until the child is adopted, the natural father of an illegitimate child is a parent within the meaning of section 4600 (In re Reyna, supra, 55 Cal.App.3d at p. 297 [ 126 Cal.Rptr. 138 ]).” (Id., at p. 199.) “[Subsequent relinquishment of the child to an adoption agency by the mother (§ 224m), [constitutes a change] of circumstance which could lead to the acquisition of custody by the natural father.” (Id., at p. 200.)

We recognize the dilemma arising under the present fact situation. The state has placed the child with prospective adoptive parents pending resolution of Edward’s claims; strong relationships have developed, and breaking those bonds could be harmful to the child.