Friday, March 31, 2023

Limpkins in Louisiana

Come for the seafood, stay to raise a family

Recently Jessa's cousin Rebekah pointed out a bird to me and asked what it was. Its appearance was distinctive, and despite never having seen one before—and despite not having expected to see one here—I was able to immediately identify it as a limpkin. (Does obsessively poring over bird books constitute a misspent youth?)

All of my field guides list Florida as the only place in the U.S. to find limpkins, but they were first seen in Louisiana in Lafourche Parish in 2017, just six years ago. The following year a breeding pair was documented in nearby Terrebonne Parish, and over the next few years reports continued to come in from these coastal parishes, where non-native Pomacea maculata apple snails had made an appearance in the mid-2000s. 

The invasive apple snails, notes non-game ornithologist Robert Dobbs of the Louisiana Department of Wildlife and Fisheries, were the key to these reported sightings and especially breeding records. Limpkins may have arrived with a storm, or under their own power, but they almost certainly would have left again without Pomacea:

They wander around naturally. They've wandered up the east coast in the past and around the southeast. Typically, when they show up out-of-range, they eat clams and other mollusks for a while, and then they leave. They generally don't persist in those odd places well outside of their core range. It's possible we had some birds wandering around and they happened upon the Terrebonne-Lafourche area, which is full of apple snails. So why leave? There's a ton of food. The habitat is good. Presumably the climate is okay. They've persisted thus far...

Persisted and spread, apparently. We saw our limpkin—and crucially, heard at least one other—at Irish Bayou in Orleans Parish. Bucks to beignets this ends up being another breeding locality for the newcomers.

A specialist uses specialised tools, and Jessa's photos—these are all hers, by the way—show a gap near the end of the bill, with the mandible tips crossing slightly. (Click to embiggen.) To extract an apple snail from its shell, the limpkin removes the operculum and extracts the snail with the forceps-like tip of the bill; when feeding on bivalves, the limpkin uses scissoring movements of the bill tip to sever the adductor muscles.

Even with these adaptations, however, limpkins are not a panacea for Louisiana's Pomacea problem. (P. maculata threatens both agricultural crops and native vegetation, and competes with crawfish as well as native snails). Robert Dobbs again:

At this point, there aren't enough limpkins to make much of an impact on the apple snail population. But if this trend continues and limpkins really do become established, it's possible that they could provide some level of bio control.

Meanwhile, birdwatchers such as ourselves can enjoy this recent addition to Louisiana's avifauna and the wild calls they add to the soundscape of the wetlands.

Monday, March 27, 2023

St. Tammany bugeaters

Our visit was impromptu, almost accidental. When in Louisiana, we always stay in St. Tammany Parish: Jessa grew up there—well, there and New Orleans East, just across Pontchartrain—and most of the people we visit live there. So Lacombe and Slidell are where we've traditionally hung our hats. This was our first time staying in Abita Springs, and I was idly scrolling Google Maps when I noticed Abita Creek Flatwoods Preserve. The website showed Sarracenia pitcher plants; I naturally thought, "Hey, wouldn't it be nice to see some pitcher plants?" So I ran it by Jessa, a.k.a. The Keeper of the Itinerary, and she agreed that this would be good to squeeze in. So then my thoughts transitioned to something like "Man, I hope we can find a pitcher plant..."

Mission accomplished. 

I think I've mentioned before that I'm nobody's botanist, but based on my pre- and post-visit research (mostly post), there are two species of pitcher plant native to St. Tammany Parish: Sarracenia alata, the pale pitcher plant, and S. psittacina, the parrot pitcher plant. S. alata has upright pitchers, yellow flowers, and was in full bloom at the time of our visit, whereas psittacina's pitchers are mostly prostrate, and it blooms reddish to purple about a month later. Without the blooms to guide us, we didn't see (or more likely didn't notice) any psittacina, but alata was hard to miss. 

It helped that Jessa already had a good idea what the blooms would look like; the flowers were practically shouting "Here we are!" while, on the first few plants at least, the pitchers were sere and brown, difficult to notice amidst all the botanical clutter of the longleaf pine savanna.

The mid-Gulf region has been described as a global hotspot for carnivorous plant diversity, and also present at the preserve are sundews. I know even less about Drosera than Sarracenia, but I believe these are either D. capillaris or D. brevifolia—very possibly both.

These are not large or conspicuous plants; we saw sundews ranging from silver-dollar size (like the specimen above) to dime size or smaller. Jessa and Rebekah got quite good at spotting them on mown paths or amongst pine needles on the savannah floor; I mainly saw the ones nestled against the exposed roots of longleaf pine.

The most subtle of the carnivorous plants we noticed were these bladderworts, Utricularia subulata (I think). The bulk of the plant, including the "trap", lies beneath the wet soil, with only the flowers being noticeable to the likes of us.

Carnivorous plants tend to attract devoted, even obsessive, admirers [helpful example], including the most important naturalist in history.

...At the present moment, I care more about Drosera than the origin of all the species in the world.

—Charles Darwin, 1860

Given my botanical limitations, many such devotees will doubtless consider the riches we saw to be so many pearls before swine—but appreciative swine, I assure you. We are immensely grateful to The Nature Conservancy for preserving this site, and now feel even more attached to our favourite parish: St. Tammany is home.

* * *

Related post: No way out.

Additional photos:

Friday, March 24, 2023

Squirrels for Karen

When she first learned of our upcoming trip, my friend and colleague Karen asked, "Are there squirrels involved?" Apparently our reputation precedes us. So, for Karen—and because that's just what we do—here are some eastern grey squirrels.

Photos by Jessa Farrell-Churchill. 

Thursday, March 23, 2023

Just add sunlight

Jessica and I have been photographing (and then posting) green anoles since our first joint trip to Louisiana back in 2012, with subsequent sessions in 2013, 2016, and 2018. Despite two visits in 2020, we evidently broke our streak. The photos below may not be the best we've ever taken, but at least we're back on track, and back in Louisiana again.

We brought a cold front with us, and when Jessa first spotted this little guy, he was brown and rather sluggish. But a few minutes and 12 frames later (not all of which were of the anole), he was in the pink green.

This second one greened up much more quickly, but then he had already been active—he came to Jessa's attention by crash-landing in front of her, and was soon doing push-ups and throat-fanning, though alas she stopped shooting before that point.

More trip photos to follow soon.

Wednesday, March 22, 2023

Brown thrasher

Then a flutter in the brush caught her eye. They sat still as a robin-size bird with a long graceful tail bounced in the undergrowth. "Is it a brown thrasher?" Margaret whispered.

Bill hesitated before he spoke. "No," he said. "It's a beige dolorosa."

Margaret squinted at him. "Are you sure?"

Bill's eyes were smiling. "Come on. Let's move." He stood up and the bird darted away.

—Dan O'Brien, Brendan Prairie 

Photos by Jessica Farrell-Churchill.