diff --git a/engine/src/modules/ecology/ecology_initializer.gd b/engine/src/modules/ecology/ecology_initializer.gd
index a4095236..6771d916 100644
--- a/engine/src/modules/ecology/ecology_initializer.gd
+++ b/engine/src/modules/ecology/ecology_initializer.gd
@@ -406,18 +406,17 @@ static func _initialize_reef_health(game_map: Variant) -> void:
 
 
 static func _derive_growth_rate(traits: Variant) -> float:
-	## r-strategy = fast growth, k-strategy = slow
-	var base: float = 0.02
+	## r-strategy = fast growth, k-strategy = slow.
+	## Tuned for damped equilibrium by ~turn 50 (M2b Block 3).
+	var base: float = 0.06  # k_strategy base (was 0.02)
 	if traits.reproduction == "r_strategy":
-		base = 0.05
-	elif traits.reproduction == "budding":
-		base = 0.04
+		base = 0.12  # r_strategy breeds fast (was 0.05)
 	# Smaller creatures reproduce faster
 	match traits.size:
 		"tiny": base *= 2.0
 		"small": base *= 1.5
 		"large": base *= 0.7
-		"huge": base *= 0.4
+		"huge": base *= 0.5
 	return base
 
 
diff --git a/engine/src/modules/ecology/fauna.gd b/engine/src/modules/ecology/fauna.gd
index ce22547a..c85bdf26 100644
--- a/engine/src/modules/ecology/fauna.gd
+++ b/engine/src/modules/ecology/fauna.gd
@@ -173,8 +173,8 @@ func _process_creature_lifecycle(
 				if health > thresh:
 					new_q = quality + 1
 
-		# Reproduction
-		if health > 0.8 and age > sp.get("maturity_age", 5):
+		# Reproduction — threshold 0.6 (tuned from 0.8 for stable populations)
+		if health > 0.6 and age > sp.get("maturity_age", 5):
 			var count: int = ecology_db.get_creature_count_on_tile(pos.x, pos.y)
 			var cap: float = sp.get("carrying_capacity", 10.0)
 			if float(count) < cap and rng.randf() < sp.get("growth_rate", 0.02):