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!

Photo of the Week – March 26, 2015

Despite snide comments from certain friends, I do – now and then – take photos of subjects other than insects and plants…

As I write this, the annual sandhill crane migration phenomenon is taking place on Nebraska’s Platte River.  The river valley abounds with tall gray birds feeding in crop fields and meadows and the sound of calling cranes fills the air.  I haven’t had a lot of time for crane photography this year, but have managed to pull the camera out of its bag a few times.  A couple weeks ago, for example, I was in a riverbank viewing blind with a group of birdwatchers, watching cranes coming in to their river roost against a rose-colored post-sunset sky.  The muted light made photography difficult, but I managed a few photos, including the one below.

Sandhill cranes landing on the Platte River, where they will roost overnight.  Because of low light levels, this photo was taken with an ISO of 2000, making it relatively grainy.
Sandhill cranes landing on the Platte River, where they will roost overnight. Because of low light levels, this photo was taken with an ISO of 2000, making it relatively grainy.

After the light and color faded a little more that evening, I decided to try a short video.  If you have never been to the Platte River during this time of year, this will give you a tiny glimpse of what it’s like to watch cranes coming to the river in the evening.

Watching cranes drop into the river at sunset is fun, but I prefer to visit them in the early morning as the roosting birds start to wake up and get ready for the day.  We have to sneak into the blind well before daylight and it’s often difficult to tell how many birds are on the river until the growing light slowly reveals their shadowy outlines.  On a good morning, we may have 10-20,000 birds or more within view as the sun comes up.  The sight and sound of those birds is astounding.  As the sun rises and the air warms up, the activity level of the birds increases, and we get to see a great deal of social behavior – preening, pair-bonding and courtship “dancing”, and aggressive posturing.  The short video below documents that kind of increasing activity through one morning this spring.

I am grateful to have a front row seat to an annual ecological phenomenon that draws birdwatchers and nature lovers from around the globe.  The sound of sandhill crane calls is a pretty great soundtrack to my spring.  The only regret I have is that the majority of crane-watchers never get to see the Platte River Prairies during the summer when – though we have no cranes around – our grasslands are teeming with the sights and sound of birds, insects, flowers, and generally spectacular prairie life.  Please come visit!

Flying cranes silhouetted against the dusk.  The Nature Conservancy's Platte River Prairies, Nebraska.
Flying cranes silhouetted against the dusk. The Nature Conservancy’s Platte River Prairies, Nebraska.  March 2015.

 

Photo of the Week – March 7, 2013

It’s March, which means the sandhill cranes are back on the Central Platte River.  Every spring, the entire mid-continent population of sandhill cranes (500,000-650,000 birds) comes to the Platte River to spend several weeks fueling up for the rest of their northward migration and breeding season.

Sandhill cranes roosting on the Platte River, just north of The Nature Conservancy's Studnicka tract.  2007 photo.
Sandhill cranes roosting on the Platte River, just north of The Nature Conservancy’s Studnicka tract. 2007 photo.

Interestingly, we seem to have fewer cranes right now (March 7) than we did in mid-February back in 2012.  The vagaries of weather – both here and in the wintering grounds in Texas, New Mexico, and northern Mexico – help drive the timing of migration.  I’m not sure exactly what cues they’re using to make their decisions, but apparently there is less urgency to leave the south this year. 

While the cranes are a little slow to arrive, vast numbers of snow geese, along with other geese and ducks, are making up for them.  The skies are full of birds and their calls, making it pretty nice to work outside (and, conversely, hard to stay inside.)

Spring is coming!

Time to Go North

I was fortunate enough to be in a viewing blind along the Platte River last Friday and Saturday nights, watching sandhill cranes coming in to roost.  Both nights had fantastic weather, beautiful sunsets, and excellent opportunities for our guests to see cranes up close.  However – there was a huge difference between the two nights in terms of the number of cranes that came in to roost.  On Friday night, we could probably see around 30,000 birds from the blind I was in.  On Saturday, the number was probably down around 5,000. 

Sandhill cranes at sunset on Friday night. As the sun went down, the numbers of cranes on the river went up. I'm not an expert at estimating numbers, but I'd guess there were at least 30,000 birds within view of the blind. A big contrast to Saturday night - though Saturday night was nothing to sneeze at, with birds landing close to the blind and a fantastic sunset as well.

It looks like this year’s early arrival of cranes on the Platte is leading to an early exit as well.  Normally, the 24th of March (Saturday’s date) sits right at, or shortly after the peak time to see sandhill cranes on the Platte.  Even if some of the early arrivals have started to head north to breed by the 24th, the numbers are still very high in most years.  This year, it was as if someone opened the gates and let them out Saturday morning, and they all rushed north at the same time.  Don’t get me wrong, there are still enough cranes around that driving the roads during the day and watching them come to the river at night are fantastic experiences.  It’s just different than it was during the 2-3 weeks leading up to last Friday.

It was especially interesting to be in the same viewing blind the night before and the night after the big departure that apparently took place during the day on Saturday.  Saturday was one of those days everyone wishes for on a weekend.  The temperature got up into the low 80’s (normal highs are 55 degrees F this time of year) with sunny skies and light winds.  Before heading to the blind, I spent the day working in the garden and playing baseball with my kids in the backyard.  It’s exactly the kind of day I expect cranes to leave and head north – except that it was a week or two before I would typically expect a mass exodus.

However, Friday’s weather was almost identical to Saturday’s weather, so why did they leave Saturday and not Friday?  On both days, we watched as groups of cranes spiraled up into the sky, riding the warm air currents until they were almost out of site.  On Friday, most of them must have come back down to roost on the river on more time, but on Saturday, they apparently got up high, liked what they saw/felt, set their wings, and glided north.  Maybe the high air currents on Saturday were coming from a different direction (south, presumably) than they were on Friday.  Maybe they used Friday as a practice day and the itch was unbearable two days in a row, so they gave in and headed out.

Going north early can be a risky venture for breeding cranes.  The primary role of the Platte River as a spring staging area is to allow cranes to build fat reserves while feeding on waste corn and invertebrates.  Those reserves are important because once they head north they typically have fewer opportunities to feed as they are busily setting up nesting territories, laying eggs, and caring for their young colts.  Heading north early means they are more likely to find breeding areas that are still frozen and inhospitable.  That can lead to additional stress, less food availability, and a greater chance that things will go badly during the nest season.  Waiting a couple weeks gives them some insurance that conditions will be better in the nesting grounds when they arrive. 

So did the cranes that left on Saturday know something?  Did they leave simply because they’d been on the Platte long enough to fill up with food and energy?  Or are they somehow picking up cues that make them feel good about the weather they’re heading into up north?  I don’t have the answers, but I was glad to be an observer when they made their choice. 

I wish them luck.

Photo of the Week – March 16, 2012

Sandhill cranes have filled the Platte River valley.   They’re in nearly every field within 5 miles (or more) of the river.  Bird watching is pretty easy when you just have to pull over to the side of the road to see a few thousand cranes feeding, dancing, and calling to each other.  It’s a great experience, and widely accessible to anyone with a car and a few extra minutes to pull off the interstate and drive a few county roads.  Sometimes, as was the case this past weekend, there is even a big white crane mixed in with the sandhill cranes – just for a little extra excitement.

On the other hand, while seeing the birds in the fields is fantastic, it pales in comparison to the experience of sitting in a viewing blind on the edge of the river watching the cranes pour out of the sky into their river roost sites in the evening, or sneaking back into the same blind early the next morning to watch them wake up. 

Looking through windows cut in the burlap front of a crane viewing blind along the Central Platte River. The birds were just waking up in the early dawn and starting to get noisy when this photo was taken.

It’s tough to beat an early morning in the blind.  Arriving well before sunrise, it’s usually hard to tell how many birds are on the dark and nearly silent river.  Then, as the light slowly comes up, thousands of silhouettes appear on the water and start to shift around.  As the sun slowly rises, so does the volume of the crane cacophany.  On most mornings, the cranes stick around for an hour or more after the sun is fully up, providing plenty of time to watch and listen to them at close range.  Awesome.

If you’ve never had the experience, what’s stopping you?  You can make reservations through Audubon’s Rowe Sanctuary or the Crane Trust Nature and Visitor Center.  While you’re in the area, stop by and hike one of the trails through our Platte River Prairies.