diff --git a/tests/unit/test_wildlife.py b/tests/unit/test_wildlife.py
new file mode 100644
index 0000000..0abdd35
--- /dev/null
+++ b/tests/unit/test_wildlife.py
@@ -0,0 +1,50 @@
+"""Tests for wildlife threat classification."""
+
+from vigilar.config import WildlifeConfig, WildlifeThreatMap, WildlifeSizeHeuristics
+from vigilar.detection.person import Detection
+from vigilar.detection.wildlife import classify_wildlife_threat
+
+
+def _make_config(**kwargs):
+    return WildlifeConfig(**kwargs)
+
+
+class TestWildlifeThreatClassification:
+    def test_bear_is_predator(self):
+        cfg = _make_config()
+        d = Detection(class_name="bear", class_id=21, confidence=0.9, bbox=(100, 100, 200, 300))
+        level, species = classify_wildlife_threat(d, cfg, frame_area=1920 * 1080)
+        assert level == "PREDATOR"
+        assert species == "bear"
+
+    def test_bird_is_passive(self):
+        cfg = _make_config()
+        d = Detection(class_name="bird", class_id=14, confidence=0.8, bbox=(10, 10, 30, 20))
+        level, species = classify_wildlife_threat(d, cfg, frame_area=1920 * 1080)
+        assert level == "PASSIVE"
+        assert species == "bird"
+
+    def test_unknown_small_is_nuisance(self):
+        cfg = _make_config()
+        d = Detection(class_name="unknown", class_id=99, confidence=0.7, bbox=(100, 100, 30, 30))
+        level, species = classify_wildlife_threat(d, cfg, frame_area=1920 * 1080)
+        assert level == "NUISANCE"
+        assert species == "unknown"
+
+    def test_unknown_medium_is_predator(self):
+        cfg = _make_config()
+        d = Detection(class_name="unknown", class_id=99, confidence=0.7, bbox=(100, 100, 300, 300))
+        level, species = classify_wildlife_threat(d, cfg, frame_area=1920 * 1080)
+        assert level == "PREDATOR"
+
+    def test_unknown_large_is_passive(self):
+        cfg = _make_config()
+        d = Detection(class_name="unknown", class_id=99, confidence=0.7, bbox=(100, 100, 600, 500))
+        level, species = classify_wildlife_threat(d, cfg, frame_area=1920 * 1080)
+        assert level == "PASSIVE"
+
+    def test_custom_threat_map(self):
+        cfg = _make_config(threat_map=WildlifeThreatMap(predator=["bear", "wolf"]))
+        d = Detection(class_name="wolf", class_id=99, confidence=0.85, bbox=(100, 100, 200, 200))
+        level, _ = classify_wildlife_threat(d, cfg, frame_area=1920 * 1080)
+        assert level == "PREDATOR"
diff --git a/vigilar/detection/wildlife.py b/vigilar/detection/wildlife.py
new file mode 100644
index 0000000..85fb175
--- /dev/null
+++ b/vigilar/detection/wildlife.py
@@ -0,0 +1,38 @@
+"""Wildlife threat level classification."""
+
+from vigilar.config import WildlifeConfig
+from vigilar.detection.person import Detection
+
+
+def classify_wildlife_threat(
+    detection: Detection,
+    config: WildlifeConfig,
+    frame_area: int,
+) -> tuple[str, str]:
+    """Classify a wildlife detection into threat level and species.
+
+    Returns (threat_level, species_name).
+    """
+    species = detection.class_name
+    threat_map = config.threat_map
+
+    # Direct COCO class mapping first
+    if species in threat_map.predator:
+        return "PREDATOR", species
+    if species in threat_map.nuisance:
+        return "NUISANCE", species
+    if species in threat_map.passive:
+        return "PASSIVE", species
+
+    # Fallback to size heuristics for unknown species
+    _, _, w, h = detection.bbox
+    bbox_area = w * h
+    area_ratio = bbox_area / frame_area if frame_area > 0 else 0
+
+    heuristics = config.size_heuristics
+    if area_ratio < heuristics.small:
+        return "NUISANCE", species
+    elif area_ratio < heuristics.medium:
+        return "PREDATOR", species
+    else:
+        return "PASSIVE", species