Recently, I noticed that the Liparis lilifolia in our woods is flowering again. I have discovered that photographing small plants at night helps to separate the subject from the background leaf litter, so I went out on Tuesday night, May 14, to take some pictures. It had been raining and was fairly warm, 65 F (18 C). As I walked through the woods, I heard frogs calling from the little wetland, really a flooded oxbow of our local creek, that is just across the lane from the south end of our property. I didn’t recognize the species (sound recording is here), so eldest offspring and I took our cameras and headlamps, and went to have a look.
A male Scaphiopus holbrookii calling for a mate
The noisemakers were eastern spadefoots (Scaphiopus holbrookii). We saw perhaps thirty of them, inflated with air and slowly circling the little pond as they called for a mate. In among the calling males were silent spadefoots that we assumed were females. I stayed for about thirty minutes, but eldest offspring texted his college room mate, another herpetology nerd, and the two of them spent several hours watching the spadefoots. They reported that by the time they left at about 01:00 am, most of the males had found females. I have long assumed that the eastern spadefoots use the oxbow as a breeding pool, but this was the first time I have heard them calling. It is nice to be proven right.
A pair in amplexus
Conditions were much the same on the night of May 15, but there was not a single spadefoot to be seen. Instead, a number of Cope’s gray treefrogs (Hyla chrysoscelis) were making a racket along the edge of the water and on the trunks of nearby trees. This little oxbow is clearly a very important site for the amphibians in our neighborhood. It retains water all summer, even when the main channel of the creek dries up, and it does not have fish that would eat amphibian eggs. In addition to the spadefoots and tree frogs, it is a breeding pool for marbled and spotted salamanders (Ambystoma opacum and A. punctatum), pickerel frogs (Lithobates palustris), chorus frogs (Pseudacris ferianum), bullfrogs (Lithobates catesbeianus), and probably other species, and it is home to one large snapping turtle (Chelydra serpentina).
Male Cope’s gray tree frog calling from the trunk of a loblolly pine on May 15. A young bullfrog at the edge of the oxbow pool on May 14 Resident snapping turtle has hauled itself (herself?) out of the oxbow pool on May 3, 2015.
Magicicada nymphs. In the next few hours, the nymph exoskeleton will split along the back, and the adult cicada will emerge. All Magicicada species have red eyes, while the larger annual cicadas have dark eyes (but see the last photo below).
After a thirteen year wait, the periodical cicadas (Magicicada species) are here again. We are in the range of Brood XIX, the Great Southern Brood, and it is exciting to see the big, bumbling insects and hear their loud, incessant chorus.
I first noticed emerging nymphs on the evening of April 25, when I saw three outside the local high school, about five miles from our house. Over the next few days, I started to see occasional adults around the garden, and I found one nymph on April 28. Then, on the evening of April 30, they emerged in force. At sunset, we could hear rustling in the leaf litter and see constant slow movement as nymphs dug themselves out of the ground. The trees and bushes were festooned with cicadas breaking out of their nymph exoskeletons and hanging motionless as their new bodies and wings hardened and darkened. Interestingly, my notes say that we noticed the last emergence when we awoke on the morning of May 1, 2011, so the brood was right on schedule: thirteen years to the day!
Adult cicada squeezing out of its nymph exoskeleton. The newly emerged adults are pale, with unexpanded wings, and their only color is in their eyes and the black patches that resemble Groucho Marx eyebrows.
Over the next few days, there were many nymphs emerging each evening, but the numbers slowly decreased. I saw only two nymphs on the evening of May 7 and none since then. Interestingly, the early stragglers that I saw last year showed up on April 28 and 29, so they were almost precisely one year early.
Another new adult that has completely emerged from its nymph exoskeleton and has expanded wings.
The noise started on May 2 (about two days before that where I work, 20 miles to the southeast) and has been slowly increasing in intensity. The drone of millions of cicadas sounds a bit like a flying saucer from some 1950s science fiction movie or, as a coworker put it, ten thousand Teslas all backing up at the same time. Over the last day or two, the predominant sound seems to have shifted to a slightly lower pitch. I wonder if that indicates that one species started calling earlier and another species has now joined the chorus.
An adult cicada that has darkened to its mature color. The dull orange patch immediately in front of the wing suggests that this is Magicicada tredecim. M. tredecassini and M. tredecula lack this feature.Another adult.
There are many web pages that describe periodical cicadas (e.g. at the University of Connecticut, where most of the information below is derived), so I won’t try to describe everything about them. I’ll just list a few facts that I find amazing–that their timekeeping is amazing goes without saying, but that’s not the only interesting thing about them:
1. The genus Magicicada contains several groups of sibling species where one species is a 17-year cicada and its sibling species is a 13-year cicada. Genetic analysis has shown that on the rare occasions when the 13-year and 17-year emergences coincide, hybridization between the sibling species can occur. For instance, 13-year M. tredecassini could potentially hybridize with 17-year M. cassini.
2. A group of cicadas on the same emergence schedule is called a brood, and a single brood can contain several species that all emerge at the same time. For instance, Brood XIX in our area contains Magicicada tredecim, M. tredecassini, and M. tredecula, all on the same schedule. Elsewhere, Brood XIX also contains M. neotredecim.
3. A Magicicada species can occur in several broods. Brood XXII also contains Magicicada tredecim, M. tredecassini, and M. tredecula, but it lacks M. neotredecim. The emergence time of Brood XXII is three years off from Brood XIX, so cicadas of the same species in the two broods will never have the opportunity to mate. A possible exception might be if stragglers emerge three years out of sync in the correct direction, but stragglers tend to emerge 1 or 4 years off-schedule.
These insects are deeply weird.
The last two nymphs that I saw. Oddly, the nymph on the right has brown eyes. It is too small and too early in the year for an annual cicada, so I suspect this is a Magicicada with aberrant eye color.Making cicadas for 2037. I hope I’ll be here to see the next emergence.
Blue-eyed grass, Sisyrhinchium species. I suspect this is either S. angustifolium or S. mucronatum, but I am not sure which.
Many people consider blue-eyed grass to be a pesky lawn weed, but I prefer to think of it as an ornament. Despite the name, blue-eyed grass is a member of iris family, Iridaceae, not a grass. Several species invade lawns in North Carolina, and their violet flowers look great along with other flowering “weeds” like yellow-flowered false strawberry (Potentilla species).
Tiny Sisyrhinchium rosulatum (fairy stars, annual blue-eyed grass) is short enough that the flowers often escape the lawnmower unscathed.
Penelope Shelley, the garden’s resident female box turtle, made her first appearance of the year this afternoon. I always try to give her a treat when I see her, but I didn’t have any berries in the refrigerator today. Instead, I scrounged around and found two earthworms, a slug, and a periodical cicada nymph. She ate everything offered and then washed it down with water from a saucer before ambling off into the undergrowth.
According to my records, the first time we encountered Penelope was on April 25, 2010, so we missed our 14th anniversary by just three days.
It has been an interesting few weeks in our garden. On April 6th, I noticed activity in a tall pine tree right beside our driveway. A pair of red-shouldered hawks (Buteo lineatus) were building a nest. As we watched, they brought twigs and other material to complete the structure, and then one of the birds settled in.
One of the few pictures I got of the presumed female on the nest. The nest is deeper than it appears, so most of the time she was invisible, with her tail only occasionally poking above the rim to prove that she was inside.
These events were surprising for several reasons. First, it was late in the season for red-shouldered hawks to start nesting. Second, a pair of hawks had been nesting in a tree on our neighbors’ property. These birds are highly territorial, suggesting that the hawks in our driveway were the same pair that had been nesting nearby earlier in the spring. Why had they moved?
The third reason that this situation was surprising became clear when I got pictures of the two birds. The bird that spent most of its time outside the nest, presumably the male, was clearly an adult-red shouldered hawk. He was very vocal, shrieking loudly throughout the day, and frequently brought small objects to the nest. On one occasion, I saw him give what appeared to be a lizard to the bird in the nest.
Adult red-shouldered hawk, presumably a male, distinguished by his rusty red chest and shoulders. He was difficult to photograph under the expanding leafy canopy.
The other bird, presumably the female, had the paler, speckled breast of an immature red-shouldered hawk. Why was she nesting with an adult male?
The presumed female hawk with the paler, speckled breast of a young bird.
When I posted pictures on the Carolinas Wildlife page on Facebook, a bird expert suggested that this might be a late-season “emergency” nest and subadult replacement mate for an adult bird that lost its original mate earlier in the season. Presumably the female was old enough to engage in courtship behavior, even though her plumage was not fully adult.
Over the next ten days or so, there was a lot of activity around the nest. One morning, I watched a gray squirrel harassing the female. It would scramble up the tree trunk and grab at the nest, quickly running away whenever the female rose and spread her wings. Last Saturday, there was major excitement and much noise when a third hawk invaded the territory of the nesting birds. The two residents quickly chased the interloper way and then sat in the trees shrieking. I could hear the third bird also calling in the distance.
One of the resident hawks, I think the female, just after chasing away an interloper.
Earlier this week, I found the completely cleaned spinal column of a snake lying under a tree. I suspect it was the remains of the hawks’ prey, although I can’t rule out an owl or one of the various mammalian predators as the perpetrator.
It has been quiet in the garden for the last few days. The deciduous canopy has filled in, so I’m not sure if the hawks are still around, or if they have moved on. Perhaps the female was too young to successfully lay and incubate eggs after all. Red-shouldered hawks often reuse nests, so if they are gone I hope they will be back next year.
Update 4/29/2024: This weekend, I heard and saw the hawks several times, mostly early in the morning. On one occasion I saw the female leaving the nest, which is now almost completely hidden by the surrounding trees. Perhaps they have eggs or chicks up there.
Sweetgum and Pines 