Don't Feed the Geese!
As you wind your way up the approach road to this short loop hike, take the time to detour into the short driving loop on your right that will wind you around to the Tree Molds... volcanic remnants wherein trees were surrounded with molten lava, leaving interesting impressions: smaller vertical caves.
At the parking lot for the Bird Park loop you will likely be assailed by the Nene, Hawaiian Geese. Do not feed them!
This loop winds you around among lush undergrowth and towering trees. Pick up the self guided tour pamphlet from the Visitor Center over in Volcano National Park... they may not be available at the trailhead, and they'll be cheaper at the Center.
About halfway around the loop you'll encounter a lava tube cave... do yourself a favor and stay out of this slimy pit... it is both dangerous and messy. Stick to admiring the varied flora displays.
When planning hikes and drives it is obvious to include this bit of touring with a nice drive up the Mauna Loa Road to the Lookout. Unfortunately, they close the road down just at the Bird Park parking area... a seasonal closure supposedly for fire danger..??? Check with the Rangers first, or just plan to walk in from the closed gate... and extra 8-9 miles up to the official trail beginning.
Some of the guide books describe the Bird Park loop nearly equal to the Kilauea Iki loop. I don't see it. It lacks the drama and diversity. If you are there, hike the loop. Enjoy the Tree Molds. If you're lucky, the road will be open and you can enjoy the drive up to a real hike!
Gate Policy: If a gate is closed upon arrival, leave it closed after you go through. If it is open, leave it open. Leaving a closed gate open may put cattle in danger. Closing an open gate may cut them off from water. Please be respectful, leave gates as found.
WARNING! Hiking and outdoor related sports can be dangerous. Be responsible and prepare for the trip. Study the area you are entering and plan accordingly. Dress for the current and unexpected weather changes. Take plenty of water. Never go alone. Make an itinerary with your plan(s), route(s), destination(s) and expected return time. Give your itinerary to trusted family and/or friends.