When the geese explode: SCVAS group trip to Merced National Wildlife Refuge

by Mar 2, 2020

On Sunday, February 23, I led a group of 15 through Merced National Wildlife Refuge on the annual SCVAS outing to that location. It was a great and enthusiastic group with a wide range of expertise, from regular visitors to the refuge to first timers. A good time was had by all, as far as I could tell.

Merced is birded via car along a 5 mile auto tour. It is a refuge were getting out along the way is okay as long as you stay near the cars, so we stopped here and there to pull out scopes and look around. There are also three short walking trails, two near the main entrance and one (bittern marsh) in the back at the rear observation platform.

We ended up taking over four hours for the tour, because it was a crazy wonderful day. The final species total was 60, which beats my previous day record for the location by five. We located an ongoing wintering female Vermillion Flycatcher that gave some of us a short (10 second or so) good, clean view followed by 20 minutes of shy obscured views where we tried to get everyone a good look. We looked for a leucistic Black Phoebe but it hid well (I saw it on a trip a month ago, and it’s gorgeous).

We had 11 species of ducks, including two or three very very distant ring-necked (not too common on this refuge). We missed Blue-winged teal but one was seen by one of the attendees the day before. We had a nice and cooperative Sora in the reeds at the front observation platform, along with a single Wilson’s snipe. We had tree swallows on the wires around the refuge, in one group we found a single early barn swallow. We saw multiple ruby-crowned kinglet, including one that presented it’s ruby crown, evidently not to us, but to another (presumed female) bird in the tree.

Out on the bittern marsh trail most of the attendees wandered out for a look at a Great Horned Owl nest with her partner in the tree near her. We saw mulitple pairs of red-tailed hawks.

And, oh yeah, we saw a few Sandhill Cranes and Geese. Just a few geese. And I should probably mention the Bald Eagles. Yes, plural: at least two, and possibly as many as four (I’m currently thinking three).

Do you know what happens when you stick 30,000 or more geese in a place with multiple hungry bald eagles?

It was glorious.

Merced is one of the refuges where Ross’s Goose is more common than Snow Goose; my estimate was 30,000+ white geese, along with 3-5,000 Greater White Fronted Goose, along with 2000+ Sandhill Cranes spread out across the refuge with a large concentration out near the back observation platform, and other groups in the meadows and in the being-mowed corn fields.

We got to the back observation platform and got out to enjoy the show and talk about how to ID Ross vs Snow (the TL;DR: if you can tell the difference between a Canada Goose and a Cackling Goose; smaller size, “button nose” beak much less prominent on the face, that’s a key to differentiating these species as well; also, the Snow goose has a visible dark “grin” between the two pieces of the beak, and the Ross’s doesn’t), and I’d suggested we keep an eye out for Eagles, since I’d seen an immature in the hour before the outing began that didn’t stick around.

By the way, we also had a flock of Cackling geese inside all of this, which was found by one of the group with great eyes and which gave us good flying looks a few times. Not too common here but nice to see.

About ten minutes after we started watching the goose flocks, I thought I saw a big brown bird with a white tail in the air, just as it flew behind a tree. I was just starting to tell the group to keep an eye it when the goose flock exploded.

Tens of thousands of birds all take to flight at once in a panic, at full yodel. Imagine yourself stuck inside a snow globe of geese that’s just been shaken. Imagine masses of these birds flying around all around and above you. Imagine thinking to yourself “why did I leave my hat in my car?”

The sound of all of those flying, panicked geese in full yodel — at some point you don’t really hear it any more, you more feel it. It’s visceral. The chaos is crazy, but within it there are lots of patterns of structure — birds DO collide at times in these mass flights and injuries can happen, but I didn’t see one happen here (fortunately). Groups will all take off en mass together, and then fly in a group among all of the other chaotic groups. Ultimately they all circle around and start settling back into the ponds and fields, and things start settling in.

And for about the next 45 minutes, we just hung around the edge of the back pond and watched repeatedly as various flocks around the refuge panic flew. Over time, most of the outlying flocks seemed to be pulling in and joining this big flock here at the back of the refuge, so we kept seeing more and more geese joining us. And then more panic flying. It was absolutely insane.

Eventually, we saw the eagle — full adult bald eagle flying about 150′ above the pond. The geese saw it, too, but at that height, all the geese did was yodel. We watched it circle for a while, then it decided to leave and flew off west out of the refuge.

Things settled down, but then birds started going off again elsewhere on the refuge. We had over a thousand sandhill cranes panic fly and yodel their way past us. Other goose flocks mass flew. Many of these ended up in this back pond with us.

We then had one more mass flight panic yodel snowglobe moment. When we were done, where in the morning we had geese spread out all over the refuge, it seemed almost all of them were now in a tight group in about half of the back pond here, very tightly packed.

We then saw the second bald eagle, again flying over the flocks. This one was an immature, 2-3 year old bird. It soared around for a while and then headed off to other areas to annoy groups of birds.

Ultimately, we got back in the cars and headed off. We soon found one of the groups of sandhills at a reasonable distance, so got out to take a good look at them. While looking at them, I found a big brown bird with a white head and tail, sitting on the ground on an island more or less in the middle of the cranes. The cranes were ignoring it, because on the ground, it’s not really a threat — it can’t exactly run up to a crane and grab it.

Much discussion: is this that first adult eagle back again? Or a third bird? in my eBird, I counted out two eagles. My guess is this was a second adult, since the first we saw flew off in the direction opposite of where we found this individual. Could it have gone out of sight and circled back? Yes. Maybe. But my gut told me it was two adults.

Was the flying immature we saw the same as the perched one I saw around 8:15AM? I’m unsure, because I couldn’t see the under wings of the perched one so I can’t really compare, so again I only counted as one bird. But I think a good argument can be made for 3 birds, and a fourth is definitely possible but unproven. That seems like a lot of eagles (a good problem to have, unless you’re a goose). From the way the flocks were mass flying, I wouldn’t be surprise at all if there was at least one more bird hunting we never saw. it was really that crazy.

After that, we made the slow drive past the now empty pastures in the back half of the auto tour (they were loaded with geese and cranes at 8AM). I did a quick look for the wintering burrowing owl and again failed to see any sign of anything not furry, and we were up against 1PM so we ended up going back to the front parking lot and dispersing. A large group of cranes was now in that front pond for good looks.

I had to tell people a couple of times that it’s not always like this on Merced. This may have been the craziest fun I’ve ever had on the refuge. I also said at one point that a lot of first time visitors tend to come for the sandhill cranes, but they tend to come back for the geese, and I saw a couple of the group nod. I know, much as I love watching the cranes and spending time with them, the geese are probably my favorites now.

The eBird checklist has 60 species on it. Not on the list because only one member saw it as we were driving was a Great Tailed Grackle. We also had a probable Common Yellowthroat but didn’t get a good enough look to count. Before we got started I also had one of those at the front deck, as well as a continuing Fox Sparrow, but the Fox Sparrow didn’t appear for the group (look for it in the grass near the ramp of the front deck, usually with some white-crowns).

Notable misses: we never saw loggerhead shrike; we missed blue-winged teal. The wintering flock of Tri-colored Blackbird was elsewhere, along with Brewer’s Blackbird. We missed, of all things, House Finch. There were few White-Faced Ibis but we got good looks.

Vermillion Flycatcher, where we’ve had wintering females in Merced for 2-3 years hiding from me, finally joins my lifer list at #301. This brings my year list to 147, which I didn’t get to until July last year (yay me), and my all time species list at Merced NWR to 131, 56% of species seen there and 11th on the list for most species seen there. This is my 13th year birding Merced, which is my favorite birding location anywhere, and it’s a joy to share it and help teach it to others once a year for SCVAS. I get good groups of people and I love doing this with them every end-of-winter.

In the next month, most of these birds will be gone, headed north for the summer nesting. Merced NWR is quiet in summer, but starting in September the fields will start to flood, and by November, they’ll be full of ducks and geese and cranes, calling and yodeling and watching the skies to see the eagles before the eagles see them…

eBird checklist for the outing (60 species)

eBird checklist for the pre-outing (8-9AM, 26 species)

(not seen during the main outing: Fox Sparrow, Common Yellowthroat)

eBird checklist for pre-scout (Feb 17, 47 species)

(not seen during the outing: Tricolored Blackbird, Great-tailed Grackle)