Red Kite and Black Kite
Red and black kites are very similar, which can confuse the inexperienced or even the experienced bird watcher. On this page I try to clarify the differences a little with many examples. The black kite is not that common in my area so I don't have as many pictures available of the many pictures of the different age clothes.
Sitting Birds
Here are two black and three red kites:
(a) Black Kite juvenile shortly after leaving the nest. Dark brown base colour, with cream feather edges on wings and centers of breast and mantle feathers. Can appear surprisingly bright depending on the lighting situation.
The head is lighter with a smooth transition to the body, the area around the eyes is typically dark.
(b) Red Kite juvenile one month after leaving the nest. Rusty red base color with sandy wing feather margins and centers of breast and mantle feathers. Generally very light, later the feathers fade even more so that they appear almost creamy white.
The head is lighter and fades from a light rust color shortly after fledging to a light brown-grey within a few weeks. The crown remains brown for a long time. The area around the eyes is a bit dark, but never as obvious as in the Black Kite.
(c) Red Kite in June of the 2nd calendar year. A mix of the old feathers of youth plumage and the new ones of adult plumage. In the example, the mantle feathers have already molted and are bright rust-red with a black shaft line. The nape feathers are still old and show bright centers. Generally very faded, sand colored look.
(d) Black Kite Adult. Dark brown with little contrast, indistinct markings.
Depending on age, the head can be brownish or gray, the area around the eyes remains slightly darkened.
Black Kites take 6-7 years to reach their full adult plumage, although little changes after the 2nd calendar year.
The beak is more black than yellow.
(e) Red Kite Adult. Lively rust colored with clear markings and high contrasts. Elytra are clearly three-colored rusty red / black / white. The head is bluish gray and in most cases clearly contrasting in color compared to the body.
The beak is variable in the proportion of black, usually more yellow.
Direct comparison in flight
Kites are mostly seen in flight. A trained eye will immediately notice some differences here. The black kite holds its wings a little lower on gliding routes, often making smaller circles. The red kite looks more elegant, with softer wing beats. Both species often flip their tails back and forth.
(a) Tail comparison
Often the indentation of the tail is consulted to distinguish the two, but on this tablet it is seen that this feature is disregarded. In most cases, the red kite has a deeper forked shock, but there are many exceptions.
(a1) shows an adult Black Kite, whose widely spread tusk is slightly rounded, i.e. shows no notching at all.
(a2) shows a young Red Kite in the same situation, whose thrust is almost straight. Compared to (b1) the black kite has a deeper forked tail!
Young red kites usually have shallow forks.
(b) In flight characteristics
One feature that is often mentioned is the "fingers". These are the outermost flight feathers, which have a narrowed tip and thus do not fully cover one another. The Black Kite (b1) has 6 and the Red Kite (b2) has 5. However, one should consider that individual feathers may be missing due to moulting. It is better to look at the pattern of the primaries.
In the Red Kite, the fingered primaries have a clear contrast between a pure white base and black tip. The black kite, on the other hand, has a faded transition from the dark tip to the gray base, in which banding can often be seen. On some black kites the primaries can be more obvious, more on that below. The black kite also has a clear banding in the middle shock feathers, but the red kite does not.
(c) In juveniles of both species, light feather centers of the body plumage and the light edges of the elytra are conspicuous. In contrast to the red kite, the basic color of the young black kite is chocolate brown.
(d) In a direct comparison you can see a clear difference in size between the two species. In the example, the larger Red Kite is chasing the smaller and more powerfully built Black Kite.
Red kite age determination in flight
(a + g) Adult 3 calendar year +
Head distinctly grey-blue, small plumage rust-red with black quill lines.
Inner shock springs unbanded. Top colorful and rich in contrast.
(b) August 2nd calendar year
Moulting violently, small plumage already with black quills, but individual feathers still from youth plumage. Continuous end binding at the joint.
(c) April 2nd calendar year
The pale feather edges of the elytra have already receded or disappeared due to wear.
(d + e ) Young bird, August 1st calendar year
All feathers fresh, light edges of all elytra, light centers of body feathers and brownish head with a faded transition to the chest.
(f) Dark bands of shock feathers indicate 3rd or maybe 4th calendar year, later middle feathers without bands.
Black kite variation
(a) This adult black kite looks strikingly similar to the red kite, but the key features are there too. The primaries and inner shock-feathers are not white but light gray, with single bands appearing here and there. 6 fingers are visible, the stature quite strong. The gray of the head is not clearly contrasted with the brown breast. The picture was taken over snow, so the colors appear more intense. Due to the posture, the notch in the tail is very clear.
(b) Medium coloring with still quite clear primaries, gray of the head runs far into the chest.
(c) Very faded feathers, very dark primary wing panel, straight kick. Hardly anything clearer.
(d) Juvenile with light feather centers
(e) Upper surface very uniformly dark brown without any contrast.
All images from my own archive, text based on my own experience.