With its triumphantly puffed-out chest and finely barred under-wings, the Japanese Sparrowhawk in flight is a sight to behold.
As part of the Accipitridae family, it’s categorized alongside other birds of prey such as buzzards and eagles, but there are many things that make the Japanese Sparrowhawk a truly unique animal. Let’s take a closer look!
Japanese Sparrowhawks typically measure between 23-30cm (9-11.8”), with a wingspan of 48-56cm (18.1-22.”).
Their most significant features are the hypnotic brown bars that run along the underside of their wings, but their tail feathers that splay into a perfect fan shape in flight can also be helpful in identifying them.
Male Vs Female
Unlike some species of birds, it’s relatively easy to distinguish male and female Japanese Sparrowhawks.
If you’re lucky enough to glass these majestic creatures through a decent pair of binoculars, the first thing you’re likely to notice is that the females are larger than the males, which is a rare ornithological trait.
The top side of the male Japanese Sparrowhawk is usually either slate gray or blue-black, while females tend to show more of a brown hue. Furthermore, adult males develop a peach section running from the throat along both sides of the chest.
Next, you may notice the difference in eye color, as the male of the species has blood-red eyes (especially older specimens), while the females have honey-yellow eyes.
You can also differentiate Japanese Sparrowhawks while they’re in flight by observing the color depth of the bars on their underparts. Male barring is fairly light, while female barring is a much deeper brown.
Are They Aggressive?
As birds of prey, Japanese Sparrowhawks can be aggressive in the wild, but will rarely approach humans or medium-sized mammals such as cats or dogs, let alone attack them.
They may show signs of aggression when they feel trapped, as any larger bird would, but generally speaking, you’ve got more to worry about from the average seagull than you do a Japanese Sparrowhawk.
Known to chase away other birds who get within 10-50 meters of their nests, they can be considered more defensive than offensive creatures.
What Adaptations Do They Have?
In order to navigate the dense forests and brush of their habitats, the Japanese Sparrowhawk has developed quite short rounded wings and long tail feathers, making them deadly hunters in both open spaces and woodland environments.
They also have slender legs and long middle digits, enabling them to catch all sorts of air- and land-dwelling prey.
Females tend to lay clutches consisting of between 2-5 eggs. Once laid, the birds will incubate the clutch for a month or so, and after hatching, the fledgling period usually lasts another month.
Most sparrowhawks will only venture as far as 20km from where they were born to find a suitable place to breed, and if the two birds return to the same mating ground in consecutive years, it’s common for them to mate again.
They’re almost entirely monogamous, but there have been a few rare observations of extra-pair copulation within the species.
Japanese Sparrowhawks are incredibly articulate birds with four primary vocalizations, the shortest of which is their battle cry that sounds like a sharp and quick “Kit” sound.
If they’re just trying to threaten predators in order to avoid a fight, you’ll hear a distinctive, descending “Pyoh-pyo” call, but this vocalization also doubles up for males as a way of communicating with their mate, and for females as a territorial declaration.
But that’s not the female’s only means of marking her territory. She will also let out a shrill and resounding “Kek-kek-kek” call to establish boundaries or as a means of food begging.
The final call of the Japanese Sparrowhawk is a gentle “Coo-coo” used by mating birds for general communication.
What Do They Eat? (Diet)
As birds of prey, roughly 90% of the Japanese Sparrowhawks diet is composed of small songbirds, but during the mating season, they’re emboldened with duty and have been known to hunt larger birds such as pigeons and partridges.
Although they do hunt from the sky sometimes, they’re most commonly seen to wait on a high branch on the edge of the woodland until a bird flies by. They then soar out of hiding, taking their prey by surprise.
While they prefer birds, they’re known to hunt rodents (including squirrels), bats, insects, and even lizards too. They’re also prolific “caching” birds, meaning they’ll save leftovers in the branches of trees to return to at a later date.
This behavior is particularly prevalent during the mating season when extra food is needed to rear their young.
Where Do They Live? (Habitat)
Despite their geographically specific name, Japanese Sparrowhawks have a relatively wide distribution.
Of course, they do live in Japan, but they’re also known to breed in southern Siberia; the southern side of the Kuril Islands in the far-eastern stretch of Russia; the Ussuri and Amur regions between Russia and China; Sakhalin, a Russian island to the North of Japan; the Korean Peninsula; northern Mongolia; and eastern China.
They are most prevalent in woodlands, but they’ve been observed in planes, on mountains, and sometimes even in cities (especially in Japan).
What Are Their Nesting Habits?
When it comes to breeding, Japanese Sparrowhawks don’t particularly have a preference in terms of altitude. As long as the area is densely forested, it doesn’t matter if their habitat is on a hill or in the lowlands.
Their nest-building period usually occurs during the first half of April. Once a pair are ready to breed, they’ll craft a nest out of twigs and leaves, hiding it close to the trunk of the tree in order to provide plenty of branch cover.
They seem to prefer coniferous trees (red pine in particular), but they’re partial to nesting in deciduous trees such as cherries and oaks as well.
The coupled Japanese Sparrowhawks will share material-gathering and nest-building duties, but there is no set workload split, as it’s known to differ from couple to couple.
How Long Do They Live? (Lifespan)
Able to survive for as long as 11 or, in some cases, even 12 years, Japanese Sparrowhawks have comparatively lengthy lifespans, although 7-8 years is considered a long innings for the males of the species.
What Predators Do They Have?
Luckily for the Japanese Sparrowhawk, it doesn’t have many natural predators. The biggest threat it faces is other, larger birds of prey, such as eagles, owls, and other species of hawks.
Foxes also pose a threat, but it’s rare that the two animals will ever be all that near to one another.
What Are Their Feathers Like?
The wing feathers of Japanese Sparrowhawks are quite thin, especially towards the outer reaches of their wingspans, and they carry a distinctive brown barring.
Their chest feathers are quite downy, protecting them from the cold as they travel at high speeds through the air.
Dark bands arc across the fan of the tail feathers, fading slowly from the tips towards the spine.
What Does Their Poop Look Like?
As they feed primarily on other birds, Japanese sparrowhawk droppings look very little like the mottled white and black splatters you’ll find on your car windshield.
They essentially look like tightly packed bundles of dark fluff and feathers with the odd bone or skull poking out.
They tend to be roughly ovoid in shape, but smaller specimens are often more circular.
Do They Migrate?
Typically speaking, when the winter months come around, Japanese Sparrowhawks will migrate to southern China or Southeast Asia; however, in certain areas of Japan, it’s been observed that they migrate southward during the fall period.
Japanese Sparrowhawks inhabiting certain areas of Taiwan and South Ryukyu are thought to be completely sedentary.
The IUCN Conservation Status scale registers Japanese Sparrowhawks as LC, which stands for “Least Concern”. They do not qualify as a threatened species, so no conservation efforts are currently being made.
Female Japanese Sparrowhawks can live up to 6 days without food, but the male can only survive for 2-3 days on an empty stomach.
Japanese Sparrowhawks were considered quite rare birds until the 70s and 80s when the breeding grounds expanded and their numbers increased significantly.
The eyes of a male Japanese Sparrowhawk start out orange-yellow and redden over time.
Female Japanese Sparrowhawks can weigh up to 45.8 grams more than males.
Japanese Sparrowhawks will abandon their nest site if other birds frequently fly around the area making lots of noise.
They’re one of the most common hawks in the Kanto region of Japan.
While male and female Japanese Sparrowhawks look very distinct, Juveniles look almost indistinguishable.
Japanese Sparrowhawks require a minimum of 354 small birds to carry them through the breeding period.
Unlike owls, Japanese Sparrowhawks are diurnal, which means they’re active during the daytime rather than at night.
When wintering, Japanese Sparrowhawks are known to take up residence in more wide-open areas such as fields and forest edges.