Parasitic Jaeger | The PhotoNaturalist

Parasitic Jaegers migrate through Lake Superior in spring and fall. We often see them harassing gulls in mid to late September off of Duluth, Minnesota’s Park Point and Wisconsin’s Wisconsin Point. Long-tailed, Pomarine and Parasitic can all be seen here, but Parasitic Jaeger is the most common by far. They will somehow single out an individual Ring-billed Gull that it feels has a crop full of food. I suppose they can see the full crop. Then they perform the bird equivalent of a aerial “dog fight” and scare the gull into coughing up its last meal. The jaeger can often catch the regurgitant in mid air!

You will see a successful “hunt” in this video. By the way, “jaeger” is “hunter” in German.

These attacks were filmed in mid September off Superior, Wisconsin’s Wisconsin Point with the Panasonic GH5 at 180 fps.

Though jaegers look superficially like a species of gull, they have a quite different lifestyle (can birds have lifestyles?). “Jaeger” is the German word for “hunter” and that is exactly how the Parasitic Jaeger makes its living on the tundra.

I found this active pair (*June 18, 2017) on a stretch of open tundra near a large pool of open water south of Launch Road. They were very curious about me…buzzing me once, but not in an aggressive manner (so I assumed they had not yet nested). But they constantly came and “visited me,” by landing nearby even as I moved away from them. This one landed very close to me on several occasions. She would then pose…as if to say, take another picture of me already!

Parasitic Jaeger yawning or trying to cough up a pellet. Churchill, Manitoba, June 2017

Since the Parasitic Jaeger diet is mostly birds and some small rodents, they do need to cough up pellets of indigestible bones and fur. Maybe that is what this one is getting ready to do. Or maybe it was just a stretch or yawn. It was NOT screeching at me! No vocalization at all.

[Sony A6500 with Canon EF 100-400mm f4.5-5.6 L IS II USM lens at 330mm; 1/500 second at f5.6; ISO 100; braced on moss hummock]

Parasitic Jaeger landing on tundra hummock. Churchill, Manitoba, June 2017

The tundra here was bordered by a small stand of Black Spruces. The jaegers only flew over the tundra and ponds.

[Canon 7D with Canon EF 400mm f5.6 USM lens; 1/3200 second at f5.6; ISO 250; +0.66 ev; handheld]

Parasitic Jaeger in flight over tundra. Churchill, Manitoba, June 2017

They are not totally dependent on lemmings and voles as are many arctic predators, including their cousins the Long-tailed Jaeger and Pomarine Jaeger; this allows them to survive and thrive even during times of low lemming populations. Small songbirds, shorebirds, lemmings, voles, ducks, ptarmigan, fish, insects, carrion and eggs of many species are all on the menu.

[Canon 7D with Canon EF 400mm f5.6 USM lens; 1/2000 second at f5.6; ISO 250; +0.66 ev; handheld]

Parasitic Jaeger Launch Road Churchill Manitoba Canada IMG_2019 Parasitic Jaeger pair nuzzling on tundra hummock. Churchill, Manitoba, June 2017

This behavior shown in the above two photos could be related to nest site selection…An article on birdsna.org (Birds of North America online) says this….

“Usually male initiates choice of a nest site by walking or flying toward a suitable site and uttering the Nest Call. At the site, both birds produce Squeaking. Male usually has neck withdrawn and beak pointing downward; female lowers her neck and pecks at male’s beak (sometimes male pecks at female’s beak). Meanwhile nesting-building movements occur mostly by the female (Scraping, Sideways Building; Perdeck 1963).”

If so, the female is doing the nuzzling and pecking at his beak in order to confirm that this is an acceptable nest site.

[Canon 7D with Canon EF 400mm f5.6 USM lens; 1/800 second at f5.6; ISO 250; +0.66 ev; handheld]

Songbirds are the main course for most nesting Parasitic Jaegers on the tundra. Studies have shown the percentage of passerines in their diet ranges from 75 to 93 percent!

If vole or lemming numbers are high, then they will eat proportionately more small rodents.

[Canon 7D with Canon EF 400mm f5.6 USM lens; 1/2000 second at f5.6; ISO 320; +0.66 ev; handheld]

Breeding range of the Parasitic Jaeger matches the range of its preferred habitat…tundra. Churchill is at the southern edge of the tundra in North America. Being circumpolar species, they also breed in Norway, Greenland, Scotland, Iceland and Siberia.

In winter, they mostly range over the oceans from southern coasts of U.S., Mexico south to both offshore coasts of South America. Feeds by forcing gulls to disgorge their last meal in flight and swooping down to catch the regurgitated mass.

Parasitic Jaeger in flight over tundra. Churchill, Manitoba, June 2017

Parasitics will hunt cooperatively, with pairs working in tandem to find and kill prey. For accessing goose and loon eggs, one bird may harass the adult off the nest and keep her distracted while the other swoops in and steals an egg.

[Canon 7D with Canon EF 400mm f5.6 USM lens; 1/2500 second at f5.6; ISO 320; +0.66 ev; handheld]

Parasitic Jaeger in flight over tundra pond. Churchill, Manitoba, June 2017

[Canon 7D with Canon EF 400mm f5.6 USM lens; 1/1000 second at f5.6; ISO 320; +0.66 ev; handheld]

Parasitic Jaeger in flight over tundra pond. Churchill, Manitoba, June 2017

[Canon 7D with Canon EF 400mm f5.6 USM lens; 1/1000 second at f5.6; ISO 320; +0.66 ev; handheld]

Parasitic Jaeger alighting on hummock. Churchill, Manitoba, June 2017

Another case where this pair seemed genuinely curious about me…and not mad or aggressive. This one landed only a short distance away. They occasionally made low flights over my head.

[Canon 7D with Canon EF 400mm f5.6 USM lens; 1/1000 second at f5.6; ISO 320; +0.66 ev; handheld]