Photo of the Week – August 16, 2018

I’ve been spending a lot of this summer at Lincoln Creek Prairie, right across town from my house.  Much of my time there has been spent working on my square meter photography project, but I’ve wandered a lot through the rest of the prairie as well.  Visiting the same site frequently always helps me appreciate the dynamic nature of prairies.  I get to track individual flower blossoms as they transform from buds to blossoms to seed heads, and watch insects move from larva/nymph stage to adult.

Last weekend,  for example, I visited the prairie two days in a row and spotted four different Chinese mantises  that had just emerged from their last molt, leaving their exoskeletons behind.  I don’t think I’ve ever seen one of those exoskeletons before, let alone four over a two day period.  I’m guessing the skeletons don’t usually hang around long before they fall, dry up, and shrivel into obscurity – not necessarily in that order.

A Chinese mantid peers at me as I eased my camera toward it.  This one was photographed a few days before I found the exoskeletons and recently-molted adults.  
This is one of four shed mantis exoskeletons I found over a two day period.

One of my most exciting finds at Lincoln Creek this month was a small bee with gorgeous blue eyes.  It was a male Tetraloniella cressoniana – something I know only because I sent the photo to  Mike Arduser for identification.  I’ve photographed this species once before, back in 2009, and I wrote about it in a 2011 blog post.  The bee is noteworthy because it is very specialized in diet – feeding only on pitcher sage, aka blue sage (Salvia azurea).  Not coincidentally, that is the flower species in both pictures I have of this species.

Ever since learning about the species from Mike, I’d been hoping to see and photograph it again.  I finally got my wish last week, on a dewy morning at Lincoln Creek.  The bee was poised on a blue sage flower, probably waiting for the prairie to warm up and dry out enough that females would emerge from their nests.  I took quite a few shots of it as I gradually edged closer and closer, until it nearly filled the frame.  As soon as I got home, I fired off one of the photos to Mike, who enthusiastically identified it for me.

A male blue sage bee, which tolerantly allowed me to photograph it – only, I assume, because no females were available to chase.

Dewy mornings have always been favorite photographic opportunities for me, especially when the wind is calm.  Insects get trapped in dew drops, making them easy to photograph, and the entire prairie glistens and sparkles as the first light of the day hits it.  Photographing individual dew drops is always alluring, but rarely turns out very well for me – my macro lens doesn’t magnify them enough for my taste, and depth-of-field issues and slight breezes increase the technical difficulty significantly.  Now and then, however, I find the right situation.  That happened last week with a big droplet near a patch of sensitive briar flowers.

A dew drop and sensitive briar flower (Mimosa quadrivalvus) made a pretty combination.

Lincoln Creek Prairie has been a favorite spot of mine since I moved to town over 20 years ago.  It’s only about a mile from my house, and is a nice restored prairie with lots of flower and insect diversity.  The prairie is small and subdivided by tree lines and roads, but none of that really affects close-up photography.  Despite having made hundreds of trips to the prairie before this summer, though, I’m still finding new subject matter and making new observations – showcasing beautifully what prairies are all about.

Photo of the Week – August 3, 2018

I walked around one of our newer prairie/wetland restoration sites yesterday morning.  The sun was just starting to punch some holes in low-lying fog and everything was wet.  A cool and wet summer morning is usually a great time to find immobile insects and photograph them, but I for some reason I wasn’t seeing much as I walked.  Not a dragonfly, not a butterfly, not even a big ol’ beetle…  I did eventually find some bees encased in dew drops, waiting for the sun to emerge to warm and dry them.

A sunflower bee (Svastra obliqua) hides beneath a wet sawtooth sunflower leaf while waiting for morning fog to completely disperse.

Unlike females, male solitary bees don’t have nests to defend and spend most of their days chasing around foraging females.  When night comes, most species (except for a few night-feeding bees) just find a convenient place to shelter until morning.  Many times, they seem to choose roost sites where they can be a little protected from potential predators, but other times they just end up on the exposed surface of a flower (the equivalent of falling asleep on their dinner plate, I guess).  Most of the bees I saw yesterday were at least somewhat hidden- which is why I had to look pretty hard to find them, but there were a few out in the open as well, including the one pictured below.

This little fella (Melissodes agilis) looks like he fell asleep and became covered in dew drops while feeding on this rosinweed plant (Silphium integrifolium).

As I wandered along a wetland swale, I was admiring one of my favorite plants – prairie gentian (Eustoma grandiflorum) – when I happened to look down inside the blossom and spotted a fuzzy little bee.  Because it seemed like a convenient and relatively safe hiding place for bees, I started looking into other flowers too, and sure enough, I found more bees.

An agile long-horned bee (Melissodes agilis) sheltering inside a prairie gentian blossom. The circular holes in the flower petals were made by a different kind of bee – a leaf cutting bee, harvesting materials for its nest construction.

All the bees I was seeing in the prairie gentian flowers looked like the same species to me, but I’ve become smart enough not to overestimate my ability to tell bee species apart, so I double checked with Mike Arduser.  Mike confirmed that they are all male agile long-horned bees (Melissodes agilis), as was the bee I’d seen on the rosinweed flower.  He said they appear to have just recently emerged, based on their fresh appearance.  I’ll take his word for that and so should you.

There are actually three bees stacked on top of each other on this flower.

Mike also confirmed that the agile long-horned bees don’t have any particular tie to prairie gentian (they don’t specialize on its pollen or use it for nesting sites or materials).  Instead, it just appears a number of them independently recognized the potential value of prairie gentian flowers as safe overnight roost sites.  If I hadn’t been specifically admiring the gentian flowers, I’m sure I wouldn’t have noticed the bees.  I’m guessing most predators wouldn’t have spotted them either, though if a smart predator had happened to find one then and decided to do what I did and check other flowers nearby, it would have had a pretty easy time filling up on bees for breakfast!

After hearing from Mike, I followed up with a series of questions I’m guessing even he can’t answer.  Among those, I’m wondering if an individual bee returns to the same roost site night after night – assuming it isn’t disturbed while sleeping the previous night.  If that hasn’t been studied, it seems like it would be relatively easy to do a mark and recapture study on them.  The trick might be to catch the bees AFTER they leave their roost, though, so they don’t associate that roost site with being caught…  Ok, maybe it wouldn’t be as easy as I was thinking.  If you try it, however, let me know what you figure out!

Back Door Thieves

I took a quick walk through one of our restored wetlands last week.  Most plants had finished blooming for the year, but in some recently-mowed patches, there were some scattered flowers of beggarticks (Bidens sp) and blue lobelia (Lobelia siphilitica). I knelt down to look more closely at some small bees I spotted crawling around on the lobelia flowers.

I saw one bee crawl in and out of one of the flowers, but for the most part, the bees (and a few flies) were all hanging around at the base of the flowers.  As I watched, I saw one slide its long tongue into the flower.  I couldn’t tell if it opened up a hole or just took advantage of one that was already there.  Either way, it was apparently “stealing” nectar from the flower through a back window rather than entering politely through the front door.

A bee inserts its tongue into the base of a lobelia flower while two flies loiter nearby.
Another bee stealing nectar.

I sent photos and questions to both Jennifer Hopwood and Mike Arduser, who are always generous about sharing their expertise with me.  They both agreed with my interpretation, and Mike added some additional information.  He said that blue lobelia flowers have slits in them that make this kind of nectar robbing pretty easy for bees.

It seems an odd strategy for a flower to make it easy for bees to steal nectar without providing any pollination services in return.  Maybe the slits serve another purpose and the benefits outweigh the costs.  Or maybe it’s just a random loophole that natural selection hasn’t yet closed.  Regardless, blue lobelia plants tend to produce copious amounts of seed, so the flowers must get enough front door visitors to do the job.

In addition to the bees, there were a lot of flies hanging around the flowers too.  Flies have pretty short tongues, and it didn’t look like any of them were sticking those tongues into the flower slits.  Instead, they seemed to be feeding on the outside surface of the flower.  Maybe nectar was seeping through those flower slits?  Or maybe the bees were a little sloppy with their drinking and the bees were cleaning up after them?  Whatever the reason, I saw at least as many flies as bees on the flowers, so there must have been some attraction.

Flies were crawling around the bases of the flowers too, apparently feeding on the leftovers.

I wish now that I’d spent more time examining the flowers, and that I’d brought one home with me so I could look at the slits under a scope.  However, I hadn’t really planned to stop at the wetland, let alone to kneel down in the mud to look at bees stealing nectar from hapless flowers.  Also, my neck was starting to throb a little from holding my head at an uncomfortable angle necessary to photograph the bees.  Instead of sticking around to learn more, I took my camera, my muddy jeans, and my sore neck back to the truck and headed home.

Little cheater…

Popular Sunflowers

Plains sunflower (Helianthus petiolaris) is an annual plant that responds quickly to bare ground in the Nebraska Sandhills.  They pop up after fire, intensive grazing, pocket gopher activity or something else allows light to hit the soil.  At times, they can be widespread, as they were the year after the 2012 drought. More often, they are found scattered about the prairie in patches of sparse vegetation.  They have started to bloom in earnest over the last couple of weeks, adding beautiful accents to the summer prairie.

Last week, I spent an hour photographing sunflowers and the wide variety of small creatures I found hanging about on them.  In just one hour, I spotted a pretty incredible abundance and diversity of invertebrates within an area smaller than my backyard.  Sunflowers, especially annual sunflowers, are considered by some to be weeds, but these native wildflowers play really important roles in prairie ecology.  Their seeds are extremely valuable as food sources for many wildlife species and their young leaves and flower buds/blossoms are quality forage for other species, including cattle.  During this time of year, the abundant and accessible pollen and nectar of the flowers is what seemed to be attracting the invertebrates I saw.  Here is a selection of photos displaying some of those sunflower visitors.

A variety of grasshopper, katydid, and tree cricket species are all commonly found feeding on the flower parts and pollen of sunflowers.  Weevils, long-horned beetles, and other beetles are also frequently seen.

Weevils and other beetles (including the one at the top right of this photo) were also present on many of the sunflowers I saw.
Hover fly
As a small female bee (Perdita albipennis) was gathering pollen from this sunflower, a male zipped in and began mating with her. She dragged him around and just kept foraging…
Wasps, like this paper wasp, were crawling around the stems and leaves of the sunflowers, apparently gathering extra-floral nectar that was also attracting abundant ants.

The abundance of herbivores, pollinators, and other insects on the flowers and vegetation of the sunflowers seemed to attract a number of predators as well, including robber flies, spiders, and assassin bugs.

A robber fly perches on a flower bud.
A tiny crab spider.
Assassin bug.
It was hard to see for sure, but I’m pretty sure this assassin bug was feeding on an individual of the same Perdita bee species shown above.

I hope these photos, all taken from a small area and within a short time period, help illustrate the kind of resource annual sunflowers can be in the Sandhills.  I’m sure many other wildflowers host similar numbers of invertebrates, but the height and conspicuous nature of sunflowers make it really easy to see and appreciate their value.

Annual sunflowers aren’t aggressive – they just take advantage of open soil and available root space.  As vegetation recovers from whatever event caused it to become sparse, sunflower abundance diminishes…until they get another opportunity to pop back from seeds and make their contribution to the prairie ecosystem.

Photo of the Week – July 28, 2017

My daughter and I are on a short working vacation in the Nebraska Sandhills this week, so I don’t have much time to write.  Instead, here are two of my favorite photos from my trip to the Niobrara Valley Preserve last week.

Prickly poppy (Argemone polyanthemos) at the Niobrara Valley Preserve.
A metallic green sweat bee (Agapostemon splendens) feeds on purple prairie clover, displaying its long tongue. (thanks to Mike Arduser for identifying this)

Photo of the Week – May 19, 2017

Over the last five years or so, I’ve been learning a lot more about pollinators, and that has changed the way I look at prairies.  As I walk around our prairies, I often think about how I would see the site if I was a bee trying to find enough nectar and pollen to both survive and provision my eggs.  Often, our prairies are full of flowers, but April and May can be pretty tough months.  The flowers that are blooming tend to be small and scattered, and I can walk a lot of steps without finding anything.

Prairie ragwort (Packera plattensis) was a welcome sight for this orange sulphur butterfly after its northward migration this spring.

The lack of available flowers in the spring is not necessarily a new thing.  Spring weather is unpredictable, and investing resources in blooming early means risking a late freeze or (in some cases) flooding rains that can scuttle the whole process.  However, many prairies today have fewer spring flowers than they used to, and restored prairies (crop fields converted back to prairie vegetation) are often low on spring flowers because finding seed for those species is difficult.  Flowering shrubs can help make up for a scarcity of spring wildflowers, but they are also less common these days than they used to be.

Shrubs like this wild plum (Prunus americana) can provide critically important pollinator resources when few wildflowers are blooming. This photo was taken back in mid-April.

Prairie managers and gardeners can both play important roles in helping to provide spring flowers for pollinators.  In prairies, allowing shrubs to grow in some areas of the landscape can benefit pollinators in the spring, but also help out increasingly rare shrub-nesting birds during the summer.  Thinking about spring flower availability might also help inform prairie management plans, and enhancing restored, or even remnant prairies, to add missing spring wildflowers might be beneficial as well.  For gardeners, adding native spring wildflowers can be both aesthetically pleasing and extremely important for the bees and other pollinators in your neighborhood.

By the time this monarch emerges as an adult in a few weeks, there should be plenty of wildflowers available for it. Hopefully, it will be competing for nectar against a number of bees and other pollinators that made it through a tough spring season.

2017 Field Days! (And a Photo Question)

Mark your calendars if you’re interested in attending either or both of our Platte River Prairies Field Days this summer.  The first will be on Thursday July 6, and will be focused on plant identification.  We’ll have several instructors on hand to lead field-based plant identification sessions in various habitats, including upland sand prairie, mesic prairie, and wetlands.  The second field day will be August 5, and will feature a wide range of topics covering prairie ecology, restoration, and management, pollinators and other invertebrates, and more.  Both days are free and open to the all ages.  Look for more details as the time grows near.

Now, a (minor) technical photo quandry I’m hoping you can help me with…

When photographing small flowers and insects, depth-of-field (the depth of an image that is in focus) is a challenge.  At close range, a camera can only bring into focus a narrow range of the image (front to back).  Deciding what needs to be in focus and what can be a little fuzzy is a constant issue, and I often try taking the image a few different ways so I can decide which I like best later.  When I’m photographing a small creature, I almost always make sure the eyes are in focus, regardless of everything else, because as viewers, our eyes are always drawn to the eyes of other creatures.

The eyes of this Woodhouse’s toad are both sharply in focus, but the tip of her nose/snout is a little out of focus – but not enough to be distracting.

When photographing the toad above, for example, I made sure the eyes were sharply in focus, even though i knew that would mean that the part of the toad closest to the camera (the center of its mouth) would appear slightly out of focus.  Because the toad was relatively large, the out-of-focus part was only a little soft and not at all distracting, making it an easy decision to prioritize the eyes being sharp.

Bee Photo #1

The other day, I was photographing a cute little green bee (Agapostemon sp.) on a dandelion flower.  I took quite a few photos, playing with the depth-of-field.  When editing the images later, I came up with two I really liked, but neither had the entire face of the bee in focus.  In the first photo (above), the front green portion of the head was in focus, along with much of the antennae, but eyes were a little soft.  In the second photo (below), the eyes are in focus, but more of the parts of the bee closer to the camera are not.  The second photo shows off the tongue and mandibles a little better, as well as the three simple eyes on the top of the bee’s head.

Bee Photo #2

Below, you can see cropped versions of both photos and compare them.  Again, the one on the left has the green part of the head in focus, while (all 5 of) the eyes are more sharp in the photo to the right.  If I follow my typical rule, I should like the second image better, but I’m not sure I agree with that in this case.  My question for you is this: as the viewer, what is the focal point in the photo?  The big compound eyes?  The point where the antennae meet the head?  Something else?   That focal point needs to be sharp, regardless of whatever silly rule I usually follow.

Here is a side by side comparison.

Ok, I know this is kind of splitting hairs, and the difference between these two photos is pretty slight, but I’ve had other situations in which the decision about whether to focus on a little critter’s eyes or another part of its face is more difficult.  I’m hoping to find out whether what I see as the focal point of these bee images is the same as what others see.  That will help me make future decisions with other images.

Thanks for your help.

Spring Obsession

Man, I sure do love Carolina anemone (Anemone carolinianum).  It’s such a beautiful plant in such a compact package.  We have a few plants blooming in our prairie garden at home, but last weekend, I went looking for more of them at Gjerloff Prairie, owned and managed by Prairie Plains Resource Institute.  I don’t visit the prairie often enough to know for sure, but it sure seemed like there were many more patches of anemone than I’d seen in previous years.

There are both blueish-purple and pale lavender-white blossoms at Gjerloff, and sometimes the two were mixed within the same patch of flowers.  Interestingly, the white ones were easier to see at a distance then the blue ones, but both hide pretty well.  I often didn’t see them until I was within 5-10 yards.  They’re short, you see…

While it is a perennial plant, my limited experience tells me Carolina anemone flourishes when the surrounding vegetation is short.  Of course, that could be a function of visibility too, but I’m guessing it doesn’t bloom well when covered by thatch and tall skeletons of plants from the previous season.  (I’d be interested to hear from others about what kinds of response to management they’ve seen with this species.)  In our Platte River Prairies, I most often see them after a summer fire or after a year of intensive grazing.  The portion of Gjerloff prairie I found them in this year was burned and grazed pretty hard last year.  Other plant species seemed to be enjoying the abundant light in the grazed area as well, including numerous rosettes of ragwort (Packera plattensis) and quite a few individuals of prairie dandelion (Nothocalais cuspidata), which was just starting to bloom.  …More on prairie dandelion in an upcoming post…

Several different small bee and fly species were feeding on the pollen of the anemone plants last weekend, including the gorgeous little Lasioglossum species shown above.  I’m guessing the anemone is a very welcome resource for those early-season pollinators.  Carolina anemone makes its pollen easy to access, and when you find one plant, there are usually quite a few more right next to it.  That’s pretty handy for a hungry bee or fly searching for something to eat across a still-mostly-brown prairie landscape.

There are lots of great spring wildflowers, but I have to say the little Carolina anemone is my favorite.  At least this week.  Although that prairie dandelion is sure cute too…  Oh, and how can you not like pussytoes?  And violets…  Hmm.

Voting Results: Prairie and Bee? or Bee in Prairie?

Back on August 4, I posted a selection of similar images and asked for help selecting the best of four compositions.  As has been the case in the past, there was no clear consensus, but there was a winner.  That winner was PHOTO NUMBER FOUR.

Bee on blazing star #4. (Vertical - just to complicate things)
This was the most popular choice from the voting.  (Though not by a landslide.)

Photo number four got 25 votes, followed by photo number one with 22 votes.  Photos number two (7 votes) and three (3 votes) lagged far behind.  However, it was interesting that all four compositions got votes, and even numbers two and three had very passionate supporters.

Bumblebee on blazing star. Photo #1.
This one (photo number one) finished a close second to photo number four.

For many people, the choice came down to whether or not the image was a photo of a prairie landscape with a bee in it (#1) or a photo of a bee in a prairie landscape (#4).  Some people liked the “surprise” of seeing the bee upon looking closely at a prairie.  Others enjoyed the more exposed bee in the vertical photo.

For what it’s worth, the photos were presented in the order I took them in the field.  I personally like number one best, but mainly because it best represents the feel I was trying to capture when I first saw the flowers and then discovered the bee.  I do like number four too, and remember making the decision to drop a little lower with my camera so the bee would be more visible against the sky.  …Of course, I like number two and number three too…

So, thanks for your help.  This is why photographers usually take many photos of the same subject, experimenting with various compositions.  It’s hard to know what you (or others) will like best later on.  This is also why I’ve never enjoyed photo contests.  It’s relatively easy to separate images that are technically good from those that aren’t, but the process is very subjective from there.  In some ways, a big selection of photos is much like an ecosystem – you can argue that one species/photo is more important than another, but it’s really the abundance and diversity that makes both a photo contest and ecosystem work!

Photo of the Week – August 11, 2016

I made a quick trip up to the Niobrara Valley Preserve this week.  As always, there was a treasure trove of unexpected finds.  Here are some of them.

Bison calves are growing fast. Their coats have darkened to match the adults, and their horns are starting to look like more than just little bumps.
Bison calves are growing fast. Their coats have darkened to match the adults, and their horns are starting to look like more than just little bumps.
Bison tend not to hang around wooded areas for shade, but they also like to rub on trees aggressively enough to keep them stunted or even kill them. This bull was one of several bison that had evidence of recent rubbing on eastern red cedar trees.
Bison tend not to hang around wooded areas for shade, but they also like to rub on trees aggressively enough to keep them stunted or even kill them. This bull was one of several bison I saw this week that had apparently been recently rubbing on eastern red cedar trees.  Good for them.
Robber flies are amazing predators and always fun to photograph, but this might be my favorite of all time. This gorgeous robber fly landed in a sand blowout and was consuming a leaf hopper.
Robber flies are amazing predators and always fun to photograph, but this might be my favorite of all time. This gorgeous robber fly landed in a sand blowout and was consuming a leaf hopper.
Sand bluestem (Andropogon hallii) is sometimes lumped with big bluestem (Andropogon gerardii) and sometimes considered a separate species. I'm not entering that argument. However, sand bluestem (shown here) does tend to have much hairier flowers.
Sand bluestem (Andropogon hallii) is sometimes lumped with big bluestem (Andropogon gerardii) and sometimes considered a separate species. I’m not entering that argument. However, sand bluestem (shown here) does tend to have much hairier flowers.

How many of you noticed the small larva in the above photo?  I didn’t, until I was going through the photos on the computer the day after taking them.  Look below for a more close-up view of the larva.  You can see it at its original scale just to the left of the bottom left of the inset image.

Fly larva? Whatever it is, it sure is small. Wouldn't you love to know what it's doing there?
Fly larva? Whatever it is, it sure is small. Wouldn’t you love to know what it’s doing there?
This tumbleweed (Russian thistle, aka Salsola iberica) was lodged up against a fence in a big sand blowout.
This tumbleweed (Russian thistle, aka Salsola iberica) was lodged up against a fence in a big sand blowout.
This tiny pale bee (Perdita perpallida) is a specialist in prairie clovers (Dalea species) but I've only seen it on one species - Silky prairie clover (Dalea villosa)
This tiny pale bee (Perdita perpallida) is a specialist in prairie clovers but I’ve only seen it on one species – Silky prairie clover (Dalea villosa).  Its pale color helps it blend in very well. Thanks to Mike Arduser for ID and information.
What is more evocative of the Great Plains than bison grazing in a prairie dog town as the sun goes down over an expansive grassy landscape?
What is more evocative of the Great Plains than bison grazing in a prairie dog town as the sun goes down over an expansive grassy landscape?