diff --git a/intake/source.py b/intake/source.py
index 10edaa7..aa45194 100644
--- a/intake/source.py
+++ b/intake/source.py
@@ -204,7 +204,7 @@ class LocalSource:
                 yield Item(self, json.loads(filepath.read_text(encoding="utf8")))
 
 
-def _read_stdout(process: Popen, output: list) -> None:
+def _read_stdout(process: Popen, source_name: str, output: list) -> None:
     """
     Read the subprocess's stdout into memory.
     This prevents the process from blocking when the pipe fills up.
@@ -212,13 +212,23 @@ def _read_stdout(process: Popen, output: list) -> None:
     while True:
         data = process.stdout.readline()
         if data:
-            print(f"[stdout] {data.rstrip()}", file=sys.stderr)
+            try:
+                item = json.loads(data)
+                if "id" not in item:
+                    print(f"[{source_name}:out] {data.rstrip()}", file=sys.stderr)
+                else:
+                    item_id = f"id: {item['id']}"
+                    attrs = [item_id] + [k for k in item.keys() if k != "id"]
+                    print(f"[{source_name}:item] {{ {', '.join(attrs)} }}", file=sys.stderr)
+            except json.JSONDecodeError:
+                print(f"[{source_name}:out] {data.rstrip()}", file=sys.stderr)
+
             output.append(data)
         if process.poll() is not None:
             break
 
 
-def _read_stderr(process: Popen) -> None:
+def _read_stderr(process: Popen, source_name: str) -> None:
     """
     Read the subprocess's stderr stream and pass it to logging.
     This prevents the process from blocking when the pipe fills up.
@@ -226,7 +236,7 @@ def _read_stderr(process: Popen) -> None:
     while True:
         data = process.stderr.readline()
         if data:
-            print(f"[stderr] {data.rstrip()}", file=sys.stderr)
+            print(f"[{source_name}:log] {data.rstrip()}", file=sys.stderr)
         if process.poll() is not None:
             break
 
@@ -274,9 +284,9 @@ def _execute_source_action(
 
     # Kick off monitoring threads
     output = []
-    t_stdout: Thread = Thread(target=_read_stdout, args=(process, output), daemon=True)
+    t_stdout: Thread = Thread(target=_read_stdout, args=(process, source.source_name, output), daemon=True)
     t_stdout.start()
-    t_stderr: Thread = Thread(target=_read_stderr, args=(process,), daemon=True)
+    t_stderr: Thread = Thread(target=_read_stderr, args=(process, source.source_name), daemon=True)
     t_stderr.start()
 
     # Send input to the process, if provided