As these guys may be starting to trickle back into the state any day now, I thought I’d better finish up on the spectacular times we had with these birds last winter. Here’s hoping for a repeat this winter!
A few more SEOW from last winter.
A few from a couple snow days this past January. Some of the first outings with the Canon R5. On one day, light levels were quite low and birds were at a great distance. Tried shooting with and without teleconverter to get more light. Difficult circumstances.
It’s been a while since I shared some, so here you go…
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.
That is all for tonight. I will hopefully have more photos of these species to share soon.
I processed a heap of these images. I might as well share them.
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.
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.
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).
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.
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.
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.
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.
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 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.