Auroraのスナップショット一覧がAWS CLIから取得できない件

Auroraで作ったDBのスナップショット一覧は describe-db-snapshots では取得できない:

$ aws rds describe-db-snapshots
{
    "DBSnapshots": []
}

代わりに describe-db-cluster-snapshots を使う:

$ aws rds describe-db-cluster-snapshots
{
    "DBClusterSnapshots": [
        {
            "Engine": "aurora",
            "SnapshotCreateTime": "2016-10-11T18:01:09.605Z",
            "VpcId": "vpc-XXX",
            "DBClusterIdentifier": "XXX",
            "DBClusterSnapshotArn": "arn:aws:rds:ap-northeast-1:XXX",
            "MasterUsername": "XXX",
            "LicenseModel": "aurora",
            "Status": "available",
            "PercentProgress": 100,
            "DBClusterSnapshotIdentifier": "rds:XXX",
            "KmsKeyId": "arn:aws:kms:ap-northeast-1:XXX",
            "ClusterCreateTime": "2016-10-06T00:48:22.278Z",
            "StorageEncrypted": true,
            "AllocatedStorage": 1,
            "SnapshotType": "automated",
            "AvailabilityZones": [
                "ap-northeast-1a"
            ],
            "Port": 0
        }
    ]
}

参考:
- http://recipe.kc-cloud.jp/archives/8811
- http://docs.aws.amazon.com/cli/latest/reference/rds/describe-db-cluster-snapshots.html