Season

If you found your swift in May or June, it is definitely an adult swift that has returned from Africa(!). At this time there are no chicks yet.

Month	Description
May	🟢 Arrival Only an adult swift can be found
June	🟡 Nesting and eggs Only an adult swift can be found
July	🐣 Chicks
August	🔴 Departure Abandoned and emaciated young swifts are found
September

Important: Swifts do not have a "fledgling" stage in the usual sense: once a chick leaves the nest, it can already fly and find food for itself. So do not try to place a swift on a tree branch. If a swift is on the ground, it needs help!

To determine a chick's age, use visual signs such as feathers, eyes, and behavior, and compare them with the descriptions below.

Swift Age: Development from Day 1 to Day 42

This table describes the development of common swift chicks (Apus apus) from day 1 to day 42, including appearance, behavior, and key features. "Parent feeding times" are the recorded hours when the parents arrived to feed them.

Description	Photo
First hours and first day No embryonic down. Skin is soft pink. Feather tracts are not yet defined. Beak is pale, the fold at the corners of the mouth is white. Ear openings are closed. Eyelids are shut. Body length 40 mm. Wing length 7−8 mm. Weight 3.0 (2.5−3.6) g. Parent feeding times: 5:10, 7:28, 7:56, 9:05, 10:03, 11:35, 12:29, 15:40, 15:57, 17:07, 18:29, 20:22, 20:34, 21:17, 21:35

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Day 2 Skin is light pink. Feather tracts appear as small dark dots (0.2 mm in size) on the shoulders and in the caudal area. Feather tracts are not visible on the back or belly. Ear openings are closed. Eyelids are shut. Beak and claws are darkening. Body length 56 mm. Wing length 11 mm. Weight 5.5 (5.0−6.6) g. Parent feeding times: 5:36, 7:23, 8:18, 10:03, 13:06 16:16, 17:32, 19:16, 20:36, 20:58
Day 3 Feather tracts are visible as faint dotted lines of feathers developing under the skin on the head, shoulders, wings, back, and chest feather tracts (each feather bud is 0.5 to 1.5 mm, the largest shoulder ones are 1.5 mm). Wing feather tracts appear as a dotted stripe 1 mm wide. Ear openings are closed. Eyelids are shut. Beak is light gray, claws are pale. Body length 60 mm. Wing length 12 mm. Weight 8.5 (7.5−10.4) g. Parent feeding times: 4:02, 4:13, 5:23, 5:58, 6:34, 9:22, 10:42, 12:40, 13:44, 13:57, 14:52, 16:06, 16:45, 17:56, 18:08, 20:00, 20:55
Day 4 All feather tracts are visible as dotted and dashed lines of feathers growing and developing under the skin. On the head, shoulders, wings, back, and chest feather tracts, feathers appear as dotted lines, dots, or short dashes (0.5−1 mm). Shoulder feather tracts and back dashes measure 1.5−2 mm. Beak is light gray. Egg tooth is present. Claws are pale. Ear openings are closed. Eyelids are shut. Body length 65 mm. Wing length 12−16 mm. Weight 10.7 (9.6−12.8) g. (emaciated chick — 5.6 g) Parent feeding times: 4:18, 4:51, 5:18, 6:03, 7:07, 9:01, 10:44, 11:01, 12:37, 13:12, 14:51, 15:44, 16:36, 18:07, 18:14, 19:48, 20:30, 20:44, 21:19
Day 5 Feather tracts are clearly defined as dashed bands of feathers developing under the skin (on the shoulders, back, and lateral feather tracts the feathers are 2−3 mm; on the chest and legs: 2−1.7 mm). Wing feather tracts appear as solid dark stripes 2 mm wide. Small whitish dots mark the places of future flight and tail feathers. Ear openings are closed. Eyelids are shut. Beak is dark, egg tooth remains. Claws are light gray. Body length 70−75 mm. Wing length 15−18 mm. Weight 13.0 (10.7−14.8) g. Parent feeding times: 3:47, 4:03, 4:38, 4:43, 5:25, 7:56, 10:17, 11:59, 12:55, 13:34, 14:02, 14:33, 15:38, 16:38, 17:36, 19:06, 18:44, 19:41, 20:34, 20:35, 21:25
Day 6 The chick is dark all over from feathers developing beneath the skin. Eyelids have opened. Ear opening is closed. Whitish tips of down feathers have emerged through the skin on the back (the subcutaneous portion of the feather measures 3−4 mm). Main feathers appear as pale bumps forming two stripes among the developing down feathers. The head has darkened from feathers developing under the skin. Wing feather tracts appear as dark ribbed stripes (5 mm). Flight feathers look like tiny teeth (0.2 mm). Tail feathers look the same. On the belly side, the plumage is developing under the skin (3 mm). Egg tooth remains. Body length 78−83 mm. Wing length 20−23 mm. Weight 17.5 (16.3−19.2) g. Parent feeding times: 4:14, 4:21, 6:34, 8:34, 11:50, 12:43, 13:04, 14:43, 14:45, 16:07, 17:06, 17:16, 18:47, 18:51, 20:15, 20:27, 20:59
Day 7 Down feathers have emerged from under the skin (5 mm) as tiny whitish brushes (0.5−1 mm). The lines of feathers growing under the skin have merged into dark spots and stripes on the head, wing, and shoulder feather tracts. The back, lower back, belly, and leg feather tracts are covered with dashes and strokes of subcutaneous feathers (3−6 mm). Eyes begin to open. Ear openings are slightly open. Body length 80−86 mm. Wing length 16−26 mm. Weight 16.0 (19.8−22.2) g. Parent feeding times: 3:48, 5:11, 6:51, 8:11, 9:23, 10:05, 10:29, 12:13, 13:26, 13:50, 14:36, 15:06, 16:49, 17:06, 18:26, 19:36, 20:01, 20:54, 21:13
Day 8. All feather tracts are clearly visible as ribbed and raised black stripes of feathers developing under the skin. On the lower back feather tract, the tips of feathers emerging through the skin have burst open at the ends, and numerous whitish-gray small brushes of growing down feathers have appeared (1−2 mm), with the subcutaneous part of the feather measuring (4−5 mm). Down feathers have also emerged through the skin on the chest feather tract. Beak and claws are black. Egg tooth remains. Ear opening is open. Body length 82−88 mm. Wing length 20−29 mm. Length of primary flight feathers 0.2−1.7 mm. Length of tail feathers 0.2−1.0 mm. Weight 18.0 (16.3−22.0) g. Parent feeding times: 3:39, 3:52, 4:26, 4:56, 7:02, 11:24, 12:56, 13:22, 13:50, 15:00, 15:44, 18:52, 19:59, 20:09, 21:05.
Day 9 Numerous needle-like feather pins of growing plumage have appeared on the head (1 mm), back, wings, and tail feather tracts (3−4 mm). On the shoulders, back, and upper tail coverts there are many brushes of down feathers (3−4 mm). Eyes are partly open. Ear opening is open. Body length 90−95 mm. Wing length 33−36 mm. Weight 25.0 (23.8−26.7) g. Parent feeding times: 3:59, 4:23, 4:39, 8:59, 12:07, 12:44, 13:38, 14:45, 15:02, 15:13, 15:49, 16:39, 17:25, 18:04, 19:00, 19:19, 20:02, 20:28
Day 10 Numerous brushes of down feathers (3−4 mm) are unfolding on the back and forming a sparse fluffy covering on the shoulders and caudal part of the body. Feathers of the lower back feather tract appear as small pins (1−1.5 mm). Eyes are half open. Egg tooth remains. Primary and secondary flight feathers and tail feathers look like small pins (or sheaths). Body length 98−103 mm. Wing length 37−42 mm. Length of primary flight feathers 3−8 mm. Length of tail feathers 1−3 mm. Weight 23.5 (15.5−31.1) g. Parent feeding times: 6:20, 8:59, 9:38, 12:43, 14:43, 16:29, 17:39, 18:08, 20:23, 20:45, 21:02, 21:08
Day 11 Noticeably fluffier than before. Parent feeding times: 3:46, 3:54, 4:26, 5:16, 6:31, 8:16, 9:41, 10:23, 12:44, 13:05, 14:44, 15:18, 15:57, 15:58, 16:58, 17:44, 18:54, 20:04, 20:11
Day 12 The chick looks similar to an 11-day-old, but the feather sheaths (pins) have become longer. On the head, wings, and tail feather tracts, the sheaths are 3−5 mm. On the back and caudal part of the body there are sparse brushes of down feathers (3−5 mm). Primary flight feathers (2nd−5th) are in sheaths. The larger primary coverts are of similar length. Secondary flight feathers are also in sheaths (coverts 1−4 mm). Tail feathers are in sheaths (3−5 mm), which have split at the ends. Wing length 38−45 mm. Length of primary flight feathers 4−8 mm. Length of tail feathers 3−5 mm. Weight 28.5 (24.2−34.2) g. Parent feeding times: 3:58, 5:15, 5:53, 7:22, 7:48, 8:28, 9:39, 10:03, 10:44, 11:53, 11:58, 14:15, 14:48, 15:30, 16:16, 17:41, 18:17, 19:07, 19:50, 20:42, 20:46, 21:10
Day 13 The chick is covered all over with short steel-colored feather sheaths split at the tips. On the head there are needle-like pins and small ocher-gray brushes of developing feathers (0.5−1 mm). Sparse down feathers (3−5 mm) are present on the back and belly. The chest feather tract has thin sheaths (3 mm). Primary flight feathers are in sheaths (7−8) with small brushes (0.5 mm). Secondary flight feathers are sheaths (5 mm). Tail feathers are sheaths (the central ones are short, the outer ones long). Body length 95−103 mm. Length of primary flight feathers 7−8 mm. Length of tail feathers 0.5−7 mm. Weight 28.5 (17.6−39.0) g. Parent feeding times: 4:38, 5:59, 6:06, 7:12, 8:49, 9:14, 10:57, 11:16, 13:24, 13:26, 14:38, 15:04, 15:58, 17:06, 17:11, 19:14, 19:29, 20:24, 20:33, 20:58, 21:01, 21:11
Day 14 The chick is covered with long feather sheaths split at the ends and dense down feathers. The down is strongly branched at the tips and half unfolded; fluffy brushes densely surround the main back, lower back, and belly feather tracts, which are covered with needle-like pins and sheaths. The head is covered with small grayish-ocher brushes. Primary flight feathers are in sheaths with brushes (1−4 mm). Secondary flight feathers are also in small sheaths with tiny brushes (1 mm). Tail feathers have small brushes (1−2 mm). Down feather length 5−6 mm. Length of the main feather tract sheaths — 5 mm. Body length 110 mm. Wing length 52 mm. Length of primary flight feathers 13 mm. Length of tail feathers 10 mm. Weight 28.0 (17.5−38.0) g. Parent feeding times: 3:47, 4:52, 5:00, 6:12, 7:55, 8:16, 9:52, 10:28, 12:00, 12:55, 13:14, 15:32, 15:58, 17:14, 17:16, 18:41, 18:49, 19:49, 20:31, 20:42, 20:57
Day 15 The chick is covered with long feather sheaths and dense dark gray down feathers, especially well developed around the back and lower back feather tract. The head is covered with small sheaths and brushes of main feathers. Primary flight feathers are in long sheaths with brushes (2−5 mm) at the tips. Secondary flight feathers look the same (brushes: 2−3 mm). Tail feather brushes have opened more (5−7 mm). Egg tooth is present. Body length 110 mm. Wing length 60 mm. Length of primary flight feathers 19−20 mm. Length of tail feathers 10−17 mm. Weight 33.0(28.5−37.8) g. Parent feeding times: 4:38, 4:42, 6:08, 6:26, 8:26, 9:17, 10:42, 13:58, 14:47, 16:17, 16:49, 19:00, 20:12, 20:54, 20:59
Day 16 The chick is entirely covered with small brushes of contour feathers growing and unfolding on all feather tracts (small brushes, 1−3 mm, on the head, chest, and back-lower back feather tracts). The fully unfolded down feathers are very dense and branched at the tips, surrounding the stripes of contour feathers (in small sheaths with brushes at the ends) on the back-lower back feather tract. Primary flight feathers are in brushes (5−7 mm), large coverts from 5 to 20 mm (brushes 1−6 mm). Secondary flight feathers from 5 to 20 mm (brushes 0.2−0.5 mm). Tail feathers are in long sheaths and small brushes (0.2−3 mm). Beak and claws are black. No egg tooth. Eyes are wide open (fully). Wing length 68 mm. Length of primary flight feathers 15−25 mm. Length of tail feathers 7−18 mm. Weight 35.5(26.6−45.0) g. Parent feeding times: 4:20, 4:30, 6:16, 6:38, 8:25, 9:07, 9:54, 10:20, 10:56, 12:08, 14:10, 14:45, 15:46, 16:41, 19:01, 19:13, 20:15, 20:47, 21:00
Day 17 Parent feeding times: 3:50, 3:59, 4:50, 4:51, 5:33, 6:21, 6:50, 8:16, 9:42, 10:08, 11:06, 12:01, 12:13, 13:29, rain, 16:15, 16:25, 16:55, 16:57, 18:16, 18:33, rain, 20:05
Day 18 The chick is heavily covered with dark gray fluffy down feathers. The main feather tracts, in sheaths with brushes at the ends from growing and unfolding feathers, barely protrude from beneath the downy covering. The head is feathered; around the beak are small sheaths and brushes of growing but not yet unfolded feathers. Tail feathers are unfolded by 1/2 (brushes 5−10 mm). Wing length 78 mm. Length of tail feathers 12−20 mm. Weight 37.5(32.5−43.0) g. Parent feeding times: 4:04, 4:24, 5:08, 5:59, 7:36, 9:40, 10:14, 11:19, 12:29, 12:45, 13:14, 13:23, 14:18, 14:44, 15:27, 15:35, 16:38, 16:50, 17:51, 18:17, 19:29, 19:35, 20:45, 20:49
Day 19 Parent feeding times: 4:12, 4:21, 8:25, 9:03, 11:12, 11:31, 12:53, 13:03, 14:30, 15:24, 16:30, 18:07, 18:20, 18:54, 20:13, 20:21
Day 20 The chick is feathered by 1/3, covered with large brushes of unfolding feathers. The head is fully feathered. The stripes of contour feathers on the main feather tracts clearly protrude from beneath the cover of down feathers. The chest feather tract has small feathers of unfolded plumage. Primary flight feathers are unfolded by 1/3. Tail feathers are in large brushes (12−14 mm). Wing length 82−91 mm. Length of tail feathers 8−22 mm. Weight 40.0 (31.5−48.0) g. Parent feeding times: 4:11, 4:41, 4:48, 6:37, 8:41, 11:42, 12:51, 13:35, 14:03, 15:06, 16:02, 16:30, 17:05, 17:07, 18:59, 19:07, 20:20, 20:30
Day 21 Parent feeding times: 4:37, 4:44, 6:24, 7:34, 7:34 (no, I didn't make a mistake, they arrived one right after the other), 10:48, 11:05, 13:57, 16:21, 16:56, 17:51, 18:39, 20:31, 20:33
Day 22 The chick has large feather brushes, with feathers unfolded by 1/3. The down feathers on the back and rump are 50% covered by contour feathers. On the wings and tail, the sheaths of the growing plumage are clearly visible where they are not yet covered by half-unfolded feathers. There are small brushes around the eyes and on the neck. Primary flight feathers (from the 9th to the 6th and from the 5th to the 2nd) are unfolded by about 1/2 (brushes 15−22 mm). Secondary flight feathers are also half unfolded (brushes 14 mm). Tail feather brushes (15 mm) also make up ½ of the feather. Wing length 95 mm. Length of primary flight feathers 38−42 mm. Length of tail feathers 28−34 mm. Weight 43.5 (35.7−51.0) g. Parent feeding times: 5:11, 7:12, 7:23, 8:28, 11:45, 11:47, 13:35, 14:03, 14:33, 14:34, 15:12, 17:55, 17:58, 19:22, 19:42, 20:18
Day 23 Parent feeding times: 5:40, 5:52, 9:24, 11:44, 11:56, 12:38, 13:06, 13:18, 15:53, 16:35, 16:55, 17:31, 18:48, 18:49, 20:16, 20:50
Day 24 The chick is half feathered, heavily covered with large brushes of developing, unfolding feathers. On the wings and tail, the sheaths of the half-opened plumage are not covered by the vanes of the coverts (at the same time, the wing surface is continuous, without noticeable gaps). On the neck, brushes of half-opened feathers are visible. The down feathers are covered by the feathers of the back feather tract and only show beneath the contour feathers on the shoulders and rump. Tail feathers are unfolded by 2/3 (feather vanes 20−30 mm). Wing length 105−114 mm. Length of tail feathers 35−45 mm. Weight 42.0 (30.8−52.2) g. Parent feeding times: 5:06, 5:46, 6:30, 7:02, 8:12, 8:18, 10:20, 10:25, 11:35, 12:48, 13:02, 14:59, 17:04, 18:03, 18:32, 20:02, 20:10
Day 25 Parent feeding times: 4:40, 4:58, 5:34, 5:48, 6:50, 8:32, 10:25, 10:43, 11:21, 12:33, 13:38, 14:30, 14:45, 16:36, 16:52, 18:21, 18:25, 19:28 19:49
Day 26 The chick is feathered by 2/3. Feather sheaths are visible only on the neck and tail. The rest of the upper body surface is covered by the vanes of unfolding plumage. Down feathers protrude from beneath the main plumage on the neck and near the upper tail coverts. The wing is 70% feathered. A leathery unfeathered patch is visible at the bend. The vanes of the primary flight feathers have opened by 2/3. The vanes of the tail feathers are also open along 2/3 of the feather length. Wing length 110 mm. Length of primary flight feathers 35−50 mm. Length of tail feathers 43−48 mm. Weight 44.5 (37.7−51.0) g. Parent feeding times: 5:04, 5:30, 6:07, 9:02, 10:55, 12:20, 12:35, 13:33, 16:00, 16:31, 17:58, 18:47, 20:01
Day 27 Parent feeding times: 5:20, 5:23, 8:28, 8:32, 11:06, 11:33, 12:51, 13:19, 14:57, 17:31, 17:45, 19:45
Day 28 The chick is completely covered in dark brown-black feathers with thin pale edges, clearly visible on the shoulders and head. The down feathers on the back are covered by contour feathers unfolded by ¾. On the belly there is a small patch of skin still not covered by feathers. A leathery patch not covered by feathers is also visible at the bend of the wing. The vanes of the primary flight feathers have opened by 3/4 (47−57 mm). The vanes of the tail feathers have also opened by 2/3 or ¾ of the full feather length (35−43 mm). Wing length 125 mm. Length of primary flight feathers 74−78 mm. Length of tail feathers 45−60 mm. Weight 47.5 (45.3−49.4) g. Parent feeding times: 5:11, 5:38, 6:17, 6:44, 8:11, 8:54, 11:49, 12:18, 14:32, 18:25, 19:44, 20:21
Day 29 Parent feeding times: 8:07, 10:29, 11:41, 13:05, 13:45, 15:38, 17:30, 17:46, 19:04, 20:16
Day 30 Outwardly the chick appears fully feathered, but if the plumage is blown apart, numerous brushes of unopened feathers can still be seen everywhere. From above, the wing has a continuous load-bearing surface, but the sheaths of the flight feathers are visible through the unfolded plumage. A leathery patch is visible at the bend of the wing. Vanes of the primary flight feathers 52−57 mm, sheaths 25−30 mm. Tail feather vanes 32−35 mm. Wing length 123−127 mm. Length of primary flight feathers 80−85 mm. Length of tail feathers 47−60 mm. Weight 45.5 (40.5−49.0) g. Parent feeding times: 5:13, 6:02, 6:47, 7:08, 8:42, 10:35, 11:11, 14:53, rain, 19:57
Day 31 Parent feeding times: rain, 11:15, 11:28, 13:51, 14:56, 18:37, 19:22, 20:21
Day 32 The chick is covered with well-opened feathers; sheaths are no longer visible. There are no gaps on the wing surface: the upper wing coverts have fully opened, while the lower wing coverts are still in sheaths with brushes at the ends. The primary flight feathers have not yet fully opened (vanes 54−69 mm). The secondary flight feathers have unfolded, but the bases of the feathers are still in sheaths. The tail feathers have not yet fully unfolded (vanes 39−43 mm). Wing length 128−136 mm. Length of primary flight feathers 80−87 mm. Length of tail feathers 54−60 mm. Weight 45.3 (37.0−50.5) g. Parent feeding times: One parent left for wintering, leaving the chicks in the care of the second parent, presumably the mother (but that is not certain). So we understand that the intervals between feedings for each chick increased, and the number of meals per day decreased. Light rain almost all day, 13:11, 16:52, 18:16, 19:40
Day 33 Parent feeding times: A long rain began during the night and continued all day. The parent was only able to leave the nest site toward evening and brought food only once, feeding just one chick. The second one went hungry that day. No detailed notes are available for this day yet.
Day 34 A feathered young bird. Long wings without gaps. Plumage of the back, head, and belly is fully opened. Secondary flight feathers and lower wing coverts have unfolded to the base. Primary flight feathers and lower wing coverts are still not fully unfolded; the feather sheaths are clearly visible on the underside of the wings (primary flight feather vanes 65−87 mm, sheaths 20−28 mm). Tail feathers are in sheaths at the base (15−17 mm). Wing length 137−155 mm. Length of primary flight feathers 92−95 mm. Length of tail feathers 56−63 mm. Weight 44.0 (37.5−51.0) g. Parent feeding times: 16:17, 10:20, 12:14, 15:04, 18:07, 19:59, 20:11
Day 35 Parent feeding times: 5:53, 8:32, 12:53, 13:10, 16:05, 19:24
Day 36 A feathered young bird (outwardly looks the same as on day 35). The lower wing coverts are in sheaths at the base. Primary flight feathers (9th−3rd) are in sheaths (17−25 mm). The outer tail feathers are in sheaths at the base (12−14 mm). Wing length 150−160 mm. Length of tail feathers 63−64 mm. Weight 47.5 (40.5−54.2) g. Parent feeding times: 15:14, 20:08, 19:27
Day 37 Parent feeding times: 10:24, 12:31, 13:21, 15:17, 17:16, 18:45, 19:51 At 20:20 the first chick turned 39 days old, and at 20:44 it left the nest for its first flight to Africa.
Day 38 A young bird. Dark brown-black plumage with thin pale edges densely covers the whole body surface. Brushes of feathers not yet fully opened to the base are visible on the back, rump, and lower wing coverts underneath. The primary flight feathers still have sheaths or tubes at the base (12−20 mm). The tail feathers are in sheaths at the base (10−12 mm). Wing length 160−162 mm. Length of tail feathers 60−68 mm. Weight 43.0 (34.5−47.5) g. Parent feeding times: 7:19, 11:46, 15:04, 18:36, rain Our chick weighs 42.57 g.
Day 39 The second parent spent the whole morning with the chick. It left at 7 a.m. and never returned. The chick went hungry all day. At 18:17 it turned 40 days old. During the day I examined it: weight 38.75 g, the feathers had unfolded to the base, there were no sheaths. In the evening I planned to feed it if the parent still did not return, but I did not get the chance. At 20:30 it left the nest and set off for Africa after its brother and parents. It flew off hungry. Just in case, my husband and I went out with flashlights to check, but we found no one. Safe journey!
Day 40 And these are Mikhail's chicks again
Day 41 A fully feathered young bird, differing from an adult by its lighter plumage coloration thanks to the white feather edging, especially developed on the head, wing bends, and the underside of the body. Wing length 165−173 mm. Length of tail feathers 64−70 mm. Weight 43.0 (37.0−46.7) g. The first chick left the nest during the night.
Day 42 The second chick also left the nest during the night.