specially concurring.
I agree that there is an “aversion” to changing the custody of a happy child who has spent a substantial time with the custodial parent. Translated into evidentiary language, there is a presumption in favor of maintaining the custody of a happy child with the custodial parent. This presumption is based largely on the socially desirable policy of maintaining the continuity of primary parental care as well as the equally desirable policy of maintaining some semblance of finality of custody judgments. “A party against whom a presumption is directed has the burden of proving that the nonexistence of the presumed fact is more probable than its existence.” NDREv 301. Here, I believe Ms. Delzer has failed to fulfill her burden.
I concurred in the result in Von Bank v. Von Bank, 443 N.W.2d 618 (N.D.1989), because I concluded that there was some evidence in support of the fact finder’s concern over the adverse consequences to the child’s emotional health because of the custodial mother’s planned move to an isolated rural area. In retrospect, I wish I had dissented in Von Bank, because I believe it was a close case and we ought to resolve close cases in favor of continuing the custody with the custodial parent in order to protect the desired continuity of care as well as the desired predictability of and requiem from litigation arising from custody judgments.
However, I agree that the present case is distinguishable from Von Bank. Most importantly, here, the significant changes in circumstances are not changes in the custodial parent’s circumstances at all. Instead, there are significant changes in the noncustodial parent’s circumstances. While these significant changes are not “marginal,” as they were in Orke v. Olson, 411 N.W.2d 97 (N.D.1987), but are major, material improvements in the noncustodial parent’s personality, emotional health and maturity, *748neither do these changes adversely affect the best interests of the children. Gould v. Miller, 488 N.W.2d 42 (N.D.1992). So the question is whether, given the substantial changes in circumstances of the noncustodial parent, a change in custody is required or compelled for the children’s best interests. And I use the words “required or compelled” advisedly. The trial court thought that the children’s best interests “[would] be met” by their residing with their mother. But, this is not an original custody proceeding and more is required of the fact finder than simply to find that a material change in circumstances justifies a change in custody to “meet” the children’s best interests. Blotske v. Leidholm, 487 N.W.2d 607 (N.D.1992). That is why I believe the trial court erred in changing custody. Aside from the minor maladies described in the majority opinion, the record does not suggest that the children here were languishing in their custodial parent’s care. Compare Ebertz v. Ebertz, 338 N.W.2d 651 (N.D.1983). There is nothing to indicate that these children were anything but happy, well-adjusted and secure in their present custodial arrangement. See Blotske v. Leidholm, supra.
The trial court found that the father was not promoting the best interests of the children because he “treated them unequally solely because of their sex difference.” That finding was based exclusively upon evidence that the father took his six-year-old son for a motorcycle ride, but neglected to do the same for his two-year-old daughter. Viewed in its most favorable light, I believe the evidence is insufficient as a matter of law to support that finding.
The trial court says there was a lack of nurturing and care by the father, but I searched the record in vain for support for that suggestion.
The only expert witness in the case was a psychologist. He examined the mother, but not the father, and described Ms. Del-zer’s primary asset in parenting as her capacity to be nurturing and caring with the children. She “just seems very loving and very close with the children.” But nothing in the record establishes that the father is not loving or close with the children.
The trial court, appropriately concerned about uprooting the children, asked the psychologist which home was the children's “home base,” but the expert did not know. It seems to me that it is the movant’s obligation to provide the answer to that question. Surely, we can safely assume that the home base of the children, who spent all of their time with the custodial parent, except for every other weekend visitation, is with the custodial parent and that to uproot the children from the security of that arrangement calls for compelling reasons.
The trial court was influenced by the significant improvements in the mother’s personality, psychological health and personal development, which overcame the very deficiencies that caused the court to award custody to the father in the original divorce proceeding. The trial court concluded that those significant changes produced “a more balanced or level field between the parents.” But, again, this is not an original custody proceeding and so the playing field is not as “balanced” or as “level” as the trial court believed. Instead, two years have elapsed, during which time the father has served as the primary caretaker of the children. The trial court’s assessment of the noncustodial parent’s virtues overlooks the importance of the children’s attachment to, familiarity with and reliance on their custodial caregiver, their life and their routine they have had for over two years with their father, their primary caretaker. In any change of custody proceeding, the important factor is the stability of the child’s relationship with the custodial parent. E.g., Blotske v. Leidholm, supra.
I agree with the majority that the trial court, in changing custody, failed to take into account the importance of maintaining stability and continuity in the children’s lives. This is a couple whose cooperation with visitation appears to have benefited their children. Nothing in this record suggests any compelling need to change custody. Accordingly, I believe a mistake has *749been made. I, therefore, join in the majority’s disposition.