Occasionally when trawling through the scientific literature I turn up a study that I wish I had done myself. Such is the case with this week’s feature.
The southern (oak) hairstreak is related to the species in this study. Note the antenna-like extensions on the corners of the hind wings.
Andrei Sourakov. Two heads are better than one: false head allows Calycopis cecrops (Lycaenidae) to escape predation by a Jumping Spider, Phidippus pulcherrimus (Salticidae). Journal of Natural History, 2013; 1 DOI: 10.1080/00222933.2012.759288 He conducted experimental studies focused on the shape and color pattern of the lower outer wing corner of a hairstreak. Many of the small butterflies in this group have similar patterns that appear to mimic the head (complete with eyespots and threadlike extensions resembling antennae), at the other end of the insect, and have been speculated as providing some protection from birds. His tests showed that the mimicry was 100% effective against attack by a common jumping spider. The effectiveness appeared to be enhanced by the butterflies’ behavior, moving the wings in a way unlike other butterflies. The spiders always were successful against other butterfly and moth species lacking this pattern.
Another species in the group, the banded hairstreak.
Jumping spiders in genus Phidippus have iridescent chelicerae, and the family’s characteristic large eyes.
Jumping spiders are visual hunters that leap to capture their prey, so the effectiveness of the butterflies’ deception is a well-matched defense.
We’re in the season we associate with death and decay. My own personification of this quality is a character named Fun Gus.
Fun Gus, with Carl Strang inside
The character was created by Andy Kimmel, then a public information specialist for the Forest Preserve District of DuPage County, now an executive with the Forest Preserve District of Lake County (Illinois). Gus’ original home was the Halloween program at Fullersburg Woods Forest Preserve. When I became Gus, on a few selected occasions I carried him to other venues. Once I was asked to provide a special presentation as Gus at a regional conference of heritage interpreters. One of the moments in that hour was a song I wrote for the event, “Fun Gus’ Song.” Here it is, followed by the lyrics.
This is the rare, serious side of Fun Gus. In the song he refers to fungal roles as decomposers, mycorrhizal mutualists, poisons, foods, and phosphorescent mycelia, while suggesting there may be some metaphoric value in toadstools.
Can you see me just as I am?
A mirror for your own shadow stands in every toadstool in the woods.
Last Friday a doe and her newly spot-free fawn appeared at the edge of the prairie at Mayslake Forest Preserve.
The fawn was noticeably smaller, more skittish, and shorter of body in proportion to leg length than its mother.
I am guessing that this is the fawn that was so successfully hidden on the preserve through the summer, though it is possible that this pair came onto the preserve to find respite from the frantic nuttiness of the rut.
Another mammalian development was the sudden appearance of a new muskrat house in the parking lot marsh.
This den was built in less than a week.
The other main marsh, in the stream corridor, had dried out earlier in the fall, but did not remain so for long.
Some heavy rains in recent weeks have built the central pool back up to nearly a third of its normal full size.
For the most part otherwise, the routine shutting down into winter has characterized the state of the preserve in the past month.
I have long had a fondness for turtles. These strange animals were diverse and abundant in the lake below my childhood home. Two studies of this group caught my eye in 2013.
Wang, Zhuo, et al. The draft genomes of soft-shell turtle and green sea turtle yield insights into the development and evolution of the turtle-specific body plan. Nature Genetics, 2013; DOI: 10.1038/ng.2615
As described in a ScienceDaily article. This was a genomic study with an evo-devo component that looked at those two highly different turtle species. They placed the turtles with the archosaurs (the group including dinosaurs, birds and crocodiles) rather than being more primitively reptilian. They place the split of the turtle line at 250 million years ago, coinciding with the great end-Permian extinction. Shell development makes use of genes connected with limb development (perhaps bone-extending elements that expand the ribs and sternum to form the shell? This article did not get that specific). Turtles also are found to have the greatest range of odor detection capability in vertebrates other than mammals.
A sea turtle, either the green sea turtle of the previous study or a close relative.
Tyler R. Lyson, Gabe S. Bever, Torsten M. Scheyer, Allison Y. Hsiang, Jacques A. Gauthier. Evolutionary Origin of the Turtle Shell. Current Biology, 2013; DOI: 10.1016/j.cub.2013.05.003
From a ScienceDaily article. They described a fossil from South Africa, Euntosaurus africanus, which is a transitional turtle. The ribs are widened but not fused. This animal lived 260 million years ago, in the Permian. Turtles had complete shells by 215 million years ago. Odontochelys semitestacea, a previously described Chinese fossil of 220 million years ago, had a complete plastron but incomplete carapace.
The first study used genetic methods, and therefore molecular clock estimation, to place the timing of turtle evolution. The agreement with the fossil aging in the second study is impressive.
The first field recording I made this year was at the Connor Prairie bioblitz near Indianapolis, of a mysterious cricket that sounded just like the familiar Say’s trig but was in a mesic prairie habitat and was singing too early in the season. Here is what it sounded like:
With much effort I caught one, and this clearly was no Say’s trig. I collected him.
The head is entirely dark, unlike Say’s trig (see below).
It proved to be a spring trig, in the same genus but a distinct species, and in the process of being described by specialists. Until that happens, its label in the Singing Insects of North America website is Anaxipha species G.Say’s trig has a paler head, with a dark line descending diagonally from each compound eye.
Say’s trig female
Say’s trig is abundant throughout the Chicago region, in marshes, wet meadows and bottomland woods. So far I have found the spring trig fairly common in Fulton County, Indiana, at the southeast corner of the region, but it diminishes to rare individuals in northeast Illinois. Its preference is grassy prairies and mesic meadows.
The region’s third trig species is the handsome trig, a cricket that seems to prefer brush or thinly wooded edges close to wetlands.
Its song is distinct from the other two. Each pulse of its trill has, at least to my ear, a sharp clicking or percussive quality:
A comparison of sonographs shows this difference.
Spring trig sonograph. The selected area is half a second of the recording.
Handsome trig sonograph. Again, half a second is selected.
The narrow, sharp attack at the beginning of each pulse distinguishes the handsome trig’s song.
As autumn slides into winter, it’s time to start looking back at selected scientific literature from the past year. Today’s focus is on two studies of plant development. Developmental biology has gotten a big boost in recent years by its powerful alliance with genetics and evolutionary biology. Most of that work to date has been done with animals, so it was refreshing to see these studies of plant development.
Daffodils. The following study looked at the genetic controls of the trumpet-like corona on the front of the flower.
Mark T Waters, Anna M M Tiley, Elena M Kramer, Alan W Meerow, Jane A Langdale, Robert W Scotland. The corona of the daffodil Narcissus bulbocodium shares stamen-like identity and is distinct from the orthodox floral whorls. The Plant Journal, 2013; DOI: 10.1111/tpj.12150 As described in a ScienceDaily article. This was a genetics-development study that focused on the trumpet-like projection on the daffodil flower. Though petal-like in appearance, it develops independently out of the flower platform. It is closer to stamens than petals in the genes that control its development, but is a separate structure rather than a modification of stamens.
Sauret-Güeto S, Schiessl K, Bangham A, Sablowski R, Coen E (2013). JAGGED Controls: Arabidopsis Petal Growth and Shape by Interacting with a Divergent Polarity Field. PLoS Biol, 2013 DOI: 10.1371/journal.pbio.1001550 They examined the development of leaf and petal shape, and found that certain proteins influence the directionality of cell growth and reproduction. One protein influences cells to orient toward the tip, producing a pointed shape, while another influences cells to orient toward the edge, producing a rounded shape. The proteins, of course, are produced under the direction of genes involved in tissue development. Plants need somewhat different developmental controls than animals, because their cells cannot migrate through the organism. This is why the shapes of plants are less variable than those of animals.
I promised a new winter series for this season, and today is the first installment of Sound Ideas. These posts will include sound recordings of various sorts. Some will be more informational, while others, like today’s, are intended more in fun. They often will tie to previous winter series or other earlier posts.
“John and the Evinrude” is a song, and it seems to be my Greatest Hit among adults. It tells a true story from my days as a graduate student in western Alaska. One way we paid back our host, the U.S. Fish & Wildlife Service, was to conduct goose banding roundups. These take advantage of the brief period of time when waterfowl lose all their flight feathers at once. They then can be herded into a trap and banded.
A banding session. I am holding a cackling goose in the foreground, as Dave Eisenhauer (whose thesis work was on emperor geese) looks on. In the background is Dr. Cal Lensink, then refuge manager for the Fish and Wildlife Service.
Inevitably the end of that season comes, as the geese discover they can fly again. This story begins after one such futile trip upriver. We had a bit of a challenge getting back to camp.
The other characters in the story. John Eisenhauer pulls the boat, Dave Frasier is next, and Dave Eisenhauer pushes from behind. For simplicity’s sake I combined the two Daves in the song. This Grumman was how we got out to the bigger boat when we had to anchor it far offshore, as here when we returned at low tide.