diff --git a/src/overlays/actors/ovl_En_Bird/z_en_bird.c b/src/overlays/actors/ovl_En_Bird/z_en_bird.c
index 7ee366a324..a526cea4d8 100644
--- a/src/overlays/actors/ovl_En_Bird/z_en_bird.c
+++ b/src/overlays/actors/ovl_En_Bird/z_en_bird.c
@@ -14,10 +14,10 @@ void EnBird_Destroy(Actor* thisx, PlayState* play);
 void EnBird_Update(Actor* thisx, PlayState* play);
 void EnBird_Draw(Actor* thisx, PlayState* play);
 
-void func_809C1E00(EnBird* this, s16 params);
-void func_809C1E40(EnBird* this, PlayState* play);
-void func_809C1D60(EnBird* this, PlayState* play);
-void func_809C1CAC(EnBird* this, s16 params);
+void EnBird_SetupMove(EnBird* this, s16 params);
+void EnBird_Move(EnBird* this, PlayState* play);
+void EnBird_Idle(EnBird* this, PlayState* play);
+void EnBird_SetupIdle(EnBird* this, s16 params);
 
 ActorInit En_Bird_InitVars = {
     ACTOR_EN_BIRD,
@@ -47,81 +47,75 @@ void EnBird_Init(Actor* thisx, PlayState* play) {
     SkelAnime_Init(play, &this->skelAnime, &gBirdSkel, &gBirdFlyAnim, NULL, NULL, 0);
     ActorShape_Init(&this->actor.shape, 5500, ActorShadow_DrawCircle, 4);
     this->unk_194 = 0;
-    this->unk_198 = 0;
-    this->unk_1C0 = 0x9C4;
+    this->timer = 0;
+    this->rotYStep = 2500;
     this->actor.colChkInfo.mass = 0;
-    this->unk_1A8 = 1.5f;
-    this->unk_1AC = 0.5f;
-    this->unk_1A0 = 0.0f;
-    this->unk_1A4 = 0.0f;
-    this->unk_1B8 = 0.0f;
-    this->unk_1B0 = 40.0f;
+    this->speedXZTarget = 1.5f;
+    this->speedXZStep = 0.5f;
+    this->posYMag = 0.0f;
+    this->rotYMag = 0.0f;
+    this->posYPhaseStep = 0.0f;
+    this->flightDistance = 40.0f;
     this->unk_1BC = 70.0f;
-    func_809C1CAC(this, this->actor.params);
+    EnBird_SetupIdle(this, this->actor.params);
 }
 
 void EnBird_Destroy(Actor* thisx, PlayState* play) {
 }
 
-void func_809C1CAC(EnBird* this, s16 params) {
+void EnBird_SetupIdle(EnBird* this, s16 params) {
     f32 frameCount = Animation_GetLastFrame(&gBirdFlyAnim);
-    f32 playbackSpeed = this->unk_19C ? 0.0f : 1.0f;
-    AnimationHeader* anim = &gBirdFlyAnim;
+    f32 playbackSpeed = this->scaleAnimSpeed ? 0.0f : 1.0f;
 
-    this->unk_198 = Rand_S16Offset(5, 0x23);
-    Animation_Change(&this->skelAnime, anim, playbackSpeed, 0.0f, frameCount, ANIMMODE_LOOP, 0.0f);
-    EnBird_SetupAction(this, func_809C1D60);
+    this->timer = Rand_S16Offset(5, 35);
+    Animation_Change(&this->skelAnime, &gBirdFlyAnim, playbackSpeed, 0.0f, frameCount, ANIMMODE_LOOP, 0.0f);
+    EnBird_SetupAction(this, EnBird_Idle);
 }
 
-void func_809C1D60(EnBird* this, PlayState* play) {
-    f32 fVar2 = sinf(this->unk_1B4);
-
-    this->actor.shape.yOffset = this->actor.shape.yOffset + fVar2 * this->unk_1A0;
+void EnBird_Idle(EnBird* this, PlayState* play) {
+    this->actor.shape.yOffset += sinf(this->posYPhase) * this->posYMag;
     Math_SmoothStepToF(&this->actor.speedXZ, 0.0f, 0.1f, 0.5f, 0.0f);
 
-    if (this->unk_19C != 0) {
-        this->skelAnime.playSpeed = this->actor.speedXZ + this->actor.speedXZ;
+    if (this->scaleAnimSpeed) {
+        this->skelAnime.playSpeed = this->actor.speedXZ * 2.0f;
     }
 
     SkelAnime_Update(&this->skelAnime);
-    this->unk_198 -= 1;
+    this->timer--;
 
-    if (this->unk_198 <= 0) {
-        func_809C1E00(this, this->actor.params);
+    if (this->timer <= 0) {
+        EnBird_SetupMove(this, this->actor.params);
     }
 }
 
-void func_809C1E00(EnBird* this, s16 params) {
-    this->unk_198 = Rand_S16Offset(0x14, 0x2D);
-    EnBird_SetupAction(this, func_809C1E40);
+void EnBird_SetupMove(EnBird* this, s16 params) {
+    this->timer = Rand_S16Offset(20, 45);
+    EnBird_SetupAction(this, EnBird_Move);
 }
 
-void func_809C1E40(EnBird* this, PlayState* play) {
-    f32 fVar4 = sinf(this->unk_1B4);
+void EnBird_Move(EnBird* this, PlayState* play) {
+    this->actor.shape.yOffset += sinf(this->posYPhase) * this->posYMag;
+    Math_SmoothStepToF(&this->actor.speedXZ, this->speedXZTarget, 0.1f, this->speedXZStep, 0.0f);
 
-    this->actor.shape.yOffset += fVar4 * this->unk_1A0;
-    Math_SmoothStepToF(&this->actor.speedXZ, this->unk_1A8, 0.1f, this->unk_1AC, 0.0f);
-
-    if (this->unk_1B0 < Math_Vec3f_DistXZ(&this->actor.world.pos, &this->actor.home.pos) || this->unk_198 < 4) {
+    if (this->flightDistance < Math_Vec3f_DistXZ(&this->actor.world.pos, &this->actor.home.pos) || this->timer < 4) {
         Math_StepToAngleS(&this->actor.world.rot.y, Math_Vec3f_Yaw(&this->actor.world.pos, &this->actor.home.pos),
-                          this->unk_1C0);
+                          this->rotYStep);
     } else {
-        fVar4 = sinf(this->unk_1B4);
-        this->actor.world.rot.y += (s16)(fVar4 * this->unk_1A4);
+        this->actor.world.rot.y += (s16)(sinf(this->posYPhase) * this->rotYMag);
     }
 
     this->actor.shape.rot.y = this->actor.world.rot.y;
     SkelAnime_Update(&this->skelAnime);
-    this->unk_198 -= 1;
-    if (this->unk_198 < 0) {
-        func_809C1CAC(this, this->actor.params);
+    this->timer--;
+    if (this->timer < 0) {
+        EnBird_SetupIdle(this, this->actor.params);
     }
 }
 
 void EnBird_Update(Actor* thisx, PlayState* play) {
     EnBird* this = (EnBird*)thisx;
 
-    this->unk_1B4 += this->unk_1B8;
+    this->posYPhase += this->posYPhaseStep;
     this->actionFunc(this, play);
 }
 
diff --git a/src/overlays/actors/ovl_En_Bird/z_en_bird.h b/src/overlays/actors/ovl_En_Bird/z_en_bird.h
index a8a745f2da..589b72b01f 100644
--- a/src/overlays/actors/ovl_En_Bird/z_en_bird.h
+++ b/src/overlays/actors/ovl_En_Bird/z_en_bird.h
@@ -12,19 +12,18 @@ typedef struct EnBird {
     /* 0x0000 */ Actor actor;
     /* 0x014C */ SkelAnime skelAnime;
     /* 0x0190 */ EnBirdActionFunc actionFunc;
-    /* 0x0194 */ u32 unk_194;
-    /* 0x0198 */ s32 unk_198;
-    /* 0x019C */ s16 unk_19C;
-    /* 0x019E */ char unk_19E[0x2];
-    /* 0x01A0 */ f32 unk_1A0;
-    /* 0x01A4 */ f32 unk_1A4;
-    /* 0x01A8 */ f32 unk_1A8;
-    /* 0x01AC */ f32 unk_1AC;
-    /* 0x01B0 */ f32 unk_1B0;
-    /* 0x01B4 */ f32 unk_1B4;
-    /* 0x01B8 */ f32 unk_1B8;
-    /* 0x01BC */ f32 unk_1BC;
-    /* 0x01C0 */ s16 unk_1C0;
+    /* 0x0194 */ u32 unk_194; // set to 0 but otherwise unused
+    /* 0x0198 */ s32 timer;
+    /* 0x019C */ s16 scaleAnimSpeed; // when true, anim speed scales with XZ speed while slowing down. otherwise anim plays full speed
+    /* 0x01A0 */ f32 posYMag; 
+    /* 0x01A4 */ f32 rotYMag; 
+    /* 0x01A8 */ f32 speedXZTarget;
+    /* 0x01AC */ f32 speedXZStep;
+    /* 0x01B0 */ f32 flightDistance; // radius of "home" area
+    /* 0x01B4 */ f32 posYPhase;
+    /* 0x01B8 */ f32 posYPhaseStep;
+    /* 0x01BC */ f32 unk_1BC; // set but otherwise unused.
+    /* 0x01C0 */ s16 rotYStep;
     /* 0x01C2 */ char unk_1C2[0x1A];
 } EnBird; // size = 0x01DC