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.

Short-eared Owl vs. Northern Harrier – A Case of Kleptoparasitism

Miguel and I watched as this SEOW returned to a favorite perch after just catching a vole. It wasn’t quick enough to ingest its catch and the NOHA is coming up behind to take advantage of this.

I would love to know how many thousands of years this struggle has been going on. The Short-eared Owl (SEOW) and Northern Harrier (NOHA) are separated genetically by millions of years, currently existing in separate orders. The SEOW belongs to the Strigiformes and the NOHA falls within the Accipitriformes. However, they have evolved to have similar lifestyles that have placed them in similar niches and thus, pushed them into direct competition with each other.

Yes, technically, the SEOH has developed more of a nocturnal habit and the NOHA is more active in the day. However, both species are highly crepuscular (active near dawn and dusk) and the SEOW is one of the most diurnal owl species, routinely hunting during daylight hours. They also use the same prey sources – primarily feeding on small rodents like mice and voles in winter. Additionally, both species have similar hunting strategies of flying low over the prairies, meadows and agricultural fields, using both their keen sight and hearing to locate their favorite scuffling mammals.

As the NOHA arrives, the SEOW leaps from its perch with catch in claw.

On average, harriers are roughly 25% larger than the SEOW but the wingspan of both species is nearly identical. Short-eared Owls use this increased wing area to their advantage with increased maneuverability. They can find themselves on the menu of NOHA but this is a much more challenging prey for the harriers who usually prefer their acts of kleptoparasitism (stealing another’s food).

This female NOHA rushes in talons first with her eyes on the prize.

After spending dozens of hours this season watching these two species forage across these grasslands of Lincoln County, MO I can attest that both species are terrific hunters. However, I think it’s safe to say that the SEOW has the higher success rate. They were not successful every time they plunged into the vegetation but more often than not, we saw these birds rising with a recently departed vole or mouse in their beak or claws.

An observation I found interesting is that when the SEOW made a successful kill, they almost always would fly a short distance and either eat it on the wing or, more often, would land in a new place to consume. I can only speculate that they do this because they think the act of catching the prey may alert would-be kleptoparasites and they move with the prey to get a better idea of who may be watching. On the other hand, it could be argued that this action could make it more obvious that they have had a successful kill and potentially ring the diner bell. Here is another interesting question.

Moment of impact. We can’t say for certain what happened here but I like to think the NOHA put one foot on the prey and one directly in the owl’s chest. Note that each bird pulls their head and delicate eyes as far from their opponents weapons as they can.

It’s a complicated relationship, for sure. I do not know for certain, but I would anticipate that the NOHA gets a significant portion of their caloric needs from the SEOW – or at least in this particular setting. As I mentioned earlier, the SEOW are so successful, it appears they can take this loss with little significant impact – or at least in a setting such as this with ample rodent populations. It may be a completely different scenario when they find themselves in a less productive area.

Caught in the act. I was very happy to have caught a frame that shows a foot of each bird on the vole at the same time.

On numerous occasions, Miguel and I watched as the SEOW took a much more aggressive and territorial stand. They were much more likely to pick a specific area that they foraged in and defended, often chasing NOHA and other SEOW away from their lands. NOHA, on the other hand, appear to cruise much more at random.

There is nothing particularly noteworthy ethologically speaking about this image. I just liked the shape of the SEOW with wings and tailfeathers spread and backlit by the low-hanging sun.

I have read that others have documented the swings in the numbers of SEOW from year to year and location to location based on the availability of prey. It is also well known that the SEOW is one of the most migratory of owl species. In the years we have followed these birds in Lincoln County, we can attest to this. If not already done, it would be really interesting to see the results of an in-depth look at the population dynamics and migration patterns of the SEOW and determine what role, if any, the NOHA may play.

The NOHA has its meal and the owl will likely have another for itself in little time.

Finally, I tapped into the inner comic writer in me and produced this silly little GIF that personifies the above interaction. I apologize if I offended anyone with my bad attempt at using a Cockney accent for the “villain” of this story… 😉

The Short-eared Owl – More In Flight Shots

The Short-eared Owl is a unique flyer. Birder and author Pete Dunne described them as a “…pale beer keg on wings.” Just as apt, but completely different, many have described their flight as like that of a moth, with long, straight wings that give a buoyant and unpredictable pattern that is often mixed with long periods of gliding. They have the tools of a successful hunter and although they lack the speed and power of their neighbors – the Northern Harriers, their ability to fly agilely and without making a sound, allows them to pick up their rodent prey without much apparent effort.

Short-eared Owl – In Flight Shots and Some Natural History

As you know by now, the Short-eared Owl does not nest in Missouri. It uses our state as a wintering ground and nests in the plains states and up into the tundra of Alaska and Canada. It does the same in conducive habitats in South America, Europe and Asia and is even found in Hawaii. In Missouri winters, these birds of prey feed primarily on voles, mice and other small mammals but, in the summer, they expand their diets to include almost anything they can catch including arthropods, birds, reptiles and amphibians.

The Flaming Owl

The Flaming Owl was the original English name given to the Short-eared Owl. This directly represented its Latin binomial of Asio flammeus, and assumedly refers to the fiery textures and colors of its plumage. I like to think that it might better represent the look of the bird when it is typically seen – in the golden warm light of the setting or rising sun.

Season of the Short-eared

I’ve been hunting and trying to photograph Short-eared Owls in Lincoln County, MO for nearly 10 years with mixed success. The past three years or so have been particularly challenging with lower numbers than typical, often without seeing a single owl on several outings. We hypothesize that a year or two of bad flooding in these areas adjacent to the Mississippi River have caused dramatic declines in the small rodents that these and other birds of prey need in order to spend their winters here.

Whatever the reasons, this winter (2021/2022) we are seeing incredible numbers of these long-winged beauties. Although primarily nocturnal, this species also exhibits diurnal and crepuscular habits and this is another area where we have been fortunate. I have spent close to 25 afternoons and evenings with these birds over the past six weeks, sometimes alone and sometimes with friends. On most of these days at least one or two owls were seen flying with the sun still well into the sky. This makes for excellent opportunities for observing their behaviors and working on better strategies to get the meaningful photographs we are after.

I have probably kept way too many photographs that will require purchasing new external drives much sooner than I anticipated and I have probably processed too many as well. Still, I plan on sharing many of these here over the course of the next several weeks. Hell, the season isn’t over. I’ll probably try for more before they head back to the great north for the breeding season.

Green Heron – From the Canoe

On my last trip out with the canoe, back in September, I came across this most cooperative Green Heron. It did not care at all that I was hanging out watching it hunt. It was a fun challenge, maneuvering around as quietly and methodically as I could in order to get the right light on the bird and the best background possible.

The benefits of wildlife photography from a boat.

Thank you for stopping by.

-OZB

Lone Elk Park – October 2021

The dominant bull of the park gives a glance to the group of photographers has he roams his ground.

On a crisp and beautiful autumn morning this past Halloween, the WGNSS Nature Photo Group group enjoyed the rare occasion of visiting a relatively close St. Louis County location. Part of the St. Louis County Park system, Lone Elk Park has contained herds of elk and bison in some fashion since the original introduction in 1948. This is a beloved park that offers visitors up close looks at bison, elk, deer and other wildlife. Because of the constant visitors, the animals have no fear of humans and, therefore, are an easy subject for the nature photographer.

A “small satellite male” keeps to the outer boundary of the dominant bull’s area, hoping to find a stray cow.

Due to the cooperative nature of these subjects, a long telephoto lens, typically needed for wildlife photography is not required here. However, it is a good idea to give these animals their space and use common sense to keep the proper safe distance or remain in your vehicle while photographing here. Always be aware of your surroundings and photograph in a group when possible.

I recommend a mid-range telephoto focal length – a zoom lens in the neighborhood of 100-400 mm is an ideal choice. Depending on available light, a support like a tripod or monopod may be needed. However, with modern cameras and their ability to provide acceptable results at high sensitivities, handholding is usually a viable option.

A mother cow gives her calf a reassuring muzzle nudge.

Because this is a nearby location, Lone Elk Park is a great spot to practice with wildlife while building a portfolio of a variety of images. Plan to visit during every season to include the greens of summer, the warm backgrounds associated with autumn and the snows (when available) of winter. Multiple visits will allow for photographing these animals at different life stages, such as when bull elk are in velvet in the summer or while bugling during the autumn rut. From time to time photographers have also been able to capture birthing of bison and elk and the subsequent play of the growing young. I hope to visit this location more frequently in the future.

Here are a few other images I took on this visit.

Papilio glaucus (Eastern Tiger Swallowtail)

This eastern tiger swallowtail was found in late July, preparing to pupate on an American Jointweed (Polygonella americana) at Sand Prairie Conservation Area in Scott County, MO.

Papilio glaucus (eastern tiger swallowtail) preparing to pupate.