Parasitoid Cocoon

We found this cocoon of a parasitoid wasp (Ichneumonidae) during a WGNSS Nature Photo Group Outing in September of last year. This distinctive cocoon is identified to belong to a member of the subfamily Campopleginae who are characterized as koinobiont (allows host to continue development) endoparasitoids that primarily parasitize lepidopteran hosts. We did not find any remains of a potential host nearby.

Campopleginae cocoon

Rough-legged Hawk (Buteo lagopus)

The lemmings in the sub-arctic and arctic regions of Canada and Alaska must of had a bumper year in 2021 because the mid-west United States had an irruption 2021/2022 winter season for the Rough-legged Hawk (RLHA). Lemmings are the primary food source for this beautiful species during its summer nesting cycle. Typically, during our winters, RLHA are found in ones or twos in Missouri, south to the Missouri River. Around the St. Louis area we may only see one or two birds in a typical winter. This season was quite exceptional. Looking at the occurrences for this past season documented in eBird shows this species has been seen across the state, up and down the Mississippi River, even as far south as the Arkansas border. On a birding day in February, Miguel, Dave and I counted eight as we moved along the Hwy 79 corridor.

On an early mid-February morning Miguel and I hit one of our favorite winter birding locations in St. Charles County to see what luck we could have. We knew a RLHA or two had been reported and photographed by multiple folks and we had our hopes high. Nothing much was showing up on this frigid morning but I thought to check a specific area that was off the beaten path and had a history of holding birds that wanted to get away from the busy roads and throngs of gawkers. That is when we ran into an individual RLHA of our dreams. We wound up spending hours with this cooperative bird despite freezing fingers, toes and tips of our noses. We simply stood outside our vehicles and watched as the bird perched, hover-hunted, soared and fed, all the while seeming oblivious to our presence. The following video and images are the results of this day.

Rough-legged Hawk, February, St. Charles County, MO
The entire population of RLHA migrate for the winter. The light-colored iris of this bird suggests it is a juvenile. Juveniles are very difficult to discern the sex of, but juvenile males are more likely to travel further south during their migration.

The three images above show the bird hover-hunting. This process can be seen in the video as well. The RLHA will hunt by the more typical buteo standard of sitting on a perch and waiting for the right opportunity to show itself. However, because they spend roughly half of their lives in or around the tundra biome where there are few trees or other tall perches to do so, they have developed this method of hunting that allows them to stay high above their prey. They will often start very high, using their keen eyesight to spot the motion of a rodent. They will then descend in tier-like steps, getting closer to their eventual target until finally making their catch. It is quite a sight to watch a buteo of this size hover-hunting and something I doubt I could ever get tired of watching. I think these images show some modifications that help them in hover-hunting. Their wings are longer and narrower than most buteos and their tails are longer and broader as well. With these tools they can keep their heads nearly completely stationary in the sky for minutes at a time.

Right after the catch. This is the poor mouse that was eaten in the video. During winter, hawks of this size may eat 4-8 rodents a day.
The distinctive feathered legs can be easily seen in this image. This namesake trait is referred to in not only the common name, but in the specific epithet as well – lagopus referring to “hares foot”. This trait, found only in the Rough-legged Hawk, the Ferruginous Hawk and the Golden Eagle in North America, is undoubtably an adaptation for survival in the cold environments that these birds inhabit.
Rough-legged Hawks come in a dark phase coloration as well. This bird was photographed in Lincoln County, MO this year.
This is a different juvenile that was photographed in Lincoln County, MO this season.

How I would love to see them in their nesting range some day! These birds typically nest on rocky cliffs and because there is often a lack of sticks and branches available in the tundra, they will often use caribou bones to build their nests. They line their nests with soft vegetation like moss and lichen as well as the fur and feathers of their prey.

Because they are so-well adapted to living on the wing, in more open and treeless areas, the RLHA will outcompete species like Red-tailed Hawk and Ferruginous Hawk that prefer to hunt from tall perches. If you have spent enough time in the field, you have probably watched Red-tailed Hawks attempting to hover-hunt when the winds are just right. However, they cannot keep this activity up for very long and do not do it nearly as well as RLHA.

Rough-legged Hawk taking off.

I hope this post gives a good glimpse into the winter life of the Rough-legged Hawk and why, when asked what is my favorite bird species, this is one out of ten or so that I would give as the answer.

-Ozark Bill

“Raptors” of 2021/2022 Winter Season

I know that at least one of these birds pushes the definition of a raptor a little far, but, there is no denying that each of the birds featured in this post is a truly horrific predator if your are unfortunate enough to be considered their prey. It’s been a lot of fun this season shooting these birds. I get out as much as I reasonably can and although it looks like the season is turning over, I’ll have a lot more photos of these birds to share in the following weeks.

The smallest on this short list, the American Kestrel feeds primarily on small rodents and birds during winter months. During warmer times of the year, Kestrels will include arthropods and reptiles in their diets.
Anyone who has spent any time on grasslands, marshes or other flat rural areas will know the distinct shape of the ubiquitous Northern Harrier. These low-flying raptors are the scourge of rodents trying to make their living among dead winter vegetation. In rough times, they will also kill and eat birds, including members of their own species.
The Short-eared Owl should already be pretty well known to anyone that has recently visited this blog. They are terrific predators, combining keen eyesight, hearing and the ability to fly completely silent while performing aerial acrobatics. This bird is on its way to attempt a prey capture.
This was an irruption season for the Rough-legged Hawk. Many more birds than typically seen have been observed in eastern Missouri including this very cooperative female that was photographed in St. Charles County, MO. These birds, along with Short-eared Owls, have already begun moving north towards their summer habitats.
Sure, the American White Pelican is not typically lumped in with the Raptors, but I thought this photo conveyed the ferocity that this predator can use to catch its fish prey. This is another great winter photography subject.
Finally we have the Bald Eagle. We tried a few times this season along the great Mississippi River to photograph these guys pulling stunned fish from the waters. We had some success, but unfortunately, we did not have a long enough deep freeze to bring them down river in the concentrations that photographers dream about.

That is all for tonight. I will hopefully have more photos of these species to share soon.

-Ozark Bill

Short-eared Owls – In Flight and Notes About their Vocalizations

Another thing that makes Short-eared Owls so fascinating to observe is their vocalizations. These birds make sounds in a variety of ways. First, is their primary “hoot”. I have never heard this in person because this is primarily used by males in advertising for mates and establishing territories in the nesting season. You can, however, hear the barks and screams given by both males and females on their wintering grounds. The screams seem to be primarily given while in flight and the barks can be given in flight or while perched. I do not know the purposes of these two call types but will put this on my list to research. Another sound these birds deliver is the wing clap. This seems to be primarily used by males in their courtship flights and I have not observed this yet in Missouri.