Bijdragen tot de Dierkunde, 56 (2): 181-204 — 1986

Microscopic identification of feathers and feather

fragments of Palearctic

by

Tim G. Brom

Institute of Taxonomic Zoology (Zoologisch Museum), University of Amsterdam,

P.O. Box 20125, 1000 HC Amsterdam, The Netherlands

much better and Abstract a assessment of the problem

could suggest the most adequate preventive Using light microscopy, a method has been developed for

measures. the identification of feathers and feather fragments col- of lected after collisions between birds and aircraft. Charac- LaHam (1967) started the application

of the barbules of feathers described for 22 ters downy are microscopic investigation of scrapings collected orders of birds. The of in combination with the use a key of amino from engines, combined with the use macroscopic method of comparing feathers with skins acid of and able analysis protein residues, was in a museum collection results in identificationto order or

to bird so that defective family level in 97% of the analysed bird strikes. Applica- diagnose strikes, could be into those tion of the method to other fields of biological research engines rapidly separated

is discussed. including due to either bird strikes or mechanical failures.

The microscopic structure of feathers was

Résumé first studied by Chandler (1916). He described

of feathers of North the structure pennaceous Une méthode utilisant la microscopie optique a été mise

l’identification des des American and found differences à point pour plumes et fragments birds, large

de collectés des collisions oiseaux plume après entre et between different taxa. He also examined the

avions. On décrit les caractères des barbules duveteuses downy barbules of a few and provided des 22 ordres d’oiseaux. L’utilisation d’une plumes pour evidence that the structure of these barbules is clé la des en même temps que comparaison macroscopique of and taxonomic value. muséales, diagnostic plumes avec des exemplaires de collections

dans des de collisions l’identification In the the characters of the permet 97% cas au present study,

niveau de l’ordre ou de la famille. On discute l’application downy barbules of 350 palearctic species are

de cette méthode à d’autres domaines de la recherche described.* The results have been applied to la taxonomie. biologique, y compris the identification of feather fragments collected

after collisions between birds and aircraft.

INTRODUCTION About 1400 bird-aircraft incidents have been

analysed, which allowed for a statistical evalua-

the of tion of the of birds often involved One of the first steps in solving problem groups most

birds aircraft is in bird strikes collisions between and (Brom & Buurma, 1979, 1981;

which bird Buurma establishing species are most & Brom, 1980, 1981; Buurma, 1983;

bird strike Brom, 1984; Buurma et al., 1984; for literature accident-prone. During many years,

statistics were based on observations by pilots synopsis see Brom, 1986).

and and the of ground personnel, on occurrence Feather identification is not only important

dead birds airfields. in bird strike but it has shown be found on Consequently, analysis, to

useful bird strike statistics were strongly biased by the in many areas of study: in forensic

of and science food presence large easily recognizable species as applied to criminology, con-

do and law (Buurma & Brom, 1979). These, however, taminations, wildlife enforcement

not necessarily constitute the highest risk. So if

bird identification is extended * beyond A version of this preliminary paper was sent to

this would result in interested in countries macroscopical examination, colleagues many (Brom, 1980).

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sides form the inner (Davies, 1970; Deedrick & Mullery, 1981; to outer and vanes. From

Robertson these form Olsen, 1981; et al., 1984), in barbs, barbules are branching off to

work Mes- the and inner vanules. The archeological (Hargrave, 1965; outer basal part of

and in the is singer, 1965; Bennike & Dyck, 1986), vanes more (in body feathers) or less (in

ecological studies on feeding habits of car- flight feathers) downy in character.

consist nivorous (Day, 1966; Altenburg et al., The downy barbules of a base and a

it 1982; Astier, 1982; Gilbert & Nancekivell, pennulum, and is here that we find the

features which of 1982). on many taxa birds, some-

times down to species level, can be distin-

The characters used in MATERIAL AND METHODS guished. following are

identification:

Material 1. The borders of the cells the forming pen-

nulae often swollen show are or prongs. In The examined feathers were taken from freshly dead birds

and from in the skin collection of the this the barbules divided into nodes specimens way, are

Museum Amsterdam No differences Zoologisch (ZMA). and internodes, clearly visible at lower in feather structures proved to exist when fresh feathers magnifications. Nodes vary in shape from were compared with feathers from bird skins that had round and to heart-shaped to elongated may been for preserved many years. be more or less strongly pigmented. Prongs

Methods in and curvature. vary length Collectively

nodes and prongs are called nodal structures. The characters examined in this study are found at the Nodal be 2. structures may uniformly downy base (pars plumea) of the contour feathers ofa bird

When distributed the entire of the bar- (fig. 1). making preparations, only this part is along length

taken: the barbs off close the shaft of are cut to the bule found its base downy or only at or tip. feather and are sandwiched between an object glass and a 3. The basal cells which the by barbules are cover slip, which are glued togetheralong the edges. This attached the barbs villi to may show (out- technique is simple and not time-consuming. After initial experiments with embedding substances, mounting the growths). 4. The of the barbules well the feathers dry under the cover slip turned out to be most length as as appropriate. More contrast is obtained than with the number of nodal structures per mm are employment of embedding substances which have distinctive for certain groups. Whenever unsuitable refractive indices. possible, the nodal structures have been feathers washed in Dirty or greasy are warm water to counted of 50 and their which mild has added. Then (at magnification x ) a soap or detergent been they

rinsed several times in clear the number of barbule is are water to remove soap per mm given.

with hair and dried a dryer. Dirty or twisted feathers can

be restored their usually to original shape by this pro- The intraspecific variability of these characters cedure. Different feathers require somewhat different was examined before differences between techniques ofdrying. Feathers with long and lax barbules

taxa of birds were described. (such as those of owls and other birds of prey) are more higher variation: Of five difficult to blow out as their tips tend to become tangled, a. Topical species (Black- whereas feathers from birds like waterfowl fluff up readily. headed Gull Larus ridibundus, Lapwing

The feather structures were studied by light microscopy Vanellus vanellus, Oystercatcher Haematopus using magnifications between 50 and 500 x . ostralegus, Chaffinch Fringilla coelebs, and

Skylark Alauda arvensis) an extensive series of

DESCRIPTION OF CHARACTERS feather preparations (taken from 26 different

feathers from each specimen) was examined

A is of three elements: feather composed the in order to determine the variation within an axis, the barbs, and the barbules. The proximal individual plumage. Considerable dif-

of part a feather, the calamus, is fixed in the ferences proved to exist in degree of pigmen- skin of the bird. From distal called number of the part, the tation, nodal structures per mm

off both and The shaft or rachis, barbs are branching on of barbule, length of the barbules.

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following feather regions have been found to DESCRIPTION OF ORDERS

the whole of variation within one cover range

tail The of bird follows the bird: breast, belly, under coverts, upper description species tax-

tail and onomic Voous coverts, mantle, upper wing coverts. sequence as given by (1973,

In of bird strike it is case a usually not known 1977).

feather of from which part of the bird a In addition to a description of the structure

in the tables their information the originates. So, only ranges are downy barbules, on given (instead of averages) for number of weights of the different species has been

nodes and for of barbule. In as is a factor in the per mm length included, weight key

all feather studied from each of of bird strikes This species a was analysis (Buurma, 1984).

the six regions mentioned above. From each information was mainly taken from Cramp &

5 Simmons feather at least barbules were measured (1977, 1980, 1983), Brough (1983),

from collection files in and counted for nodal structures, so the and Cramp (1985), and

result from about 30 the Museum Amsterdam. given ranges Zoologisch

measurements and counts for each species, b. Individual variation: Feathers from two 1. G aviiformes (fig. 2; table I)

of the have been individuals same species This order consists of a single family compared to establish the degree of (Gaviidae). All species have been examined. individual variation. This was done for of 800-6400 Range weights g. Black-headed Gull Larus ridibundus,

Swift — The barbules GoosanderMergus merganser, Apus apus, Description. are extremely

and Secretary Bird Sagittarius serpentarius. No short (0.5-1.1 mm). At low magnification they

variation found. intraspecific was appear filamentous, not pigmented. They

Sexual variation: In two most at their c. species (Lapwing possess prongs, conspicuously

Vanellus vanellus and Red-footed Falcon Falco tips. A subdivision of the barbules is percepti-

from both have but nodes No villi vespertinus) feathers sexes ble, no enlarged are present.

been compared. Even in the highly dimor- at the basal cells.

phic Red-footed Falcon no differences were

Table I found.

Variation with and time of the Bar- Body weight (in g) and length of barbules (in mm) in d. age year: Gaviiformes. from and adult bules juvenile plumage were

for Goshawk compared Accipiter gentilis, Species body barbule

Black-headed Gull Larus ridibundus, Meadow weight length

Pipit Anthus pratensis, and Greenfinch Car- Gavia stellata Red-throated Diver 800-2460 0.5-0.9 differ duelis chloris. Nestlings and fledglings G. arctica Black-throated Diver 1200-3792 0.5-1.0

Northern Diver from older birds because the downy bar- G. immer Great 2200-4480 0.7-1.1 G. adamsii White-billed Diver 3700-6400 0.8-1.1 if and bules, present, are simple not fully

In developed. a fully developed juvenile

plumage, however, the size and structure of

the downy barbules is indistinguishable from 2. Podicipediformes (fig. 3; table II)

the adult. This order consists of a single family variation the time of the No with year was (Podicipedidae). Five species have been found. As the examined barbules are the examined. of 91-1490 Range weights g. most basal ones of the feather, located close

much — The barbules to the skin, they are not as subject to Description. are on average

in than in Gaviiformes. wear as is the plumage general. longer (0.7-1.7 mm)

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1. Position of the barbules that described in 1 = shaft = Fig. downy are this paper: or rachis, 2 calamus, 3 = vane,

4 = downy part of feather (pars plumea), 5 = barb, 6 = barbule. Fig. 2. Black-throated Diver Gavia arctica; breast feather (105 x).

Fig. 3. Black-necked Grebe Podiceps nigricollis; belly feather (165 x).

Fig. 4. Cory’s Shearwater Calonectris diomedea; mantle feather (105 x).

Fig. 5. Leach’s Storm Petrel Oceanodroma leucorhoa; mantle feather (105 x).

6. Cormorant tail Fig. Great Phalacrocorax carbo; upper covert (105 x).

and in this 3. Procellariiformes Prongs are always present at the tips (figs. 4-5; table III)

respect grebes may resemble Anseriformes, but Five species from two families (Procellariidae triangular nodes are not present. Proximally, a and Hydrobatidae) have been examined. subdivision of the barbules is perceptible, Range of weights 18-1130 g. usually indicated by prongs present at only one

of the but — side barbule, nodes cannot be Description. The barbules are extremely

counted. No villi the basal and into at cells. short (0.5-1.1 mm), a subdivision

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T able II Phalacrocoracidae: The barbules are usually

diffuse Body weight (in g) and length of barbules (in mm) in not pigmented; sometimes a pigmenta-

of Podicipediformes. tion is visible which gives the impression a

subdivision of the barbules, but nodal struc- Species body barbule tures could not be counted. At the there are weight length tips

minute which always some prongs, often are Tachybaptes only perceptible at higher magnifications; occa- ruficollis Little Grebe 91-315 0.7-1.3 the extend the entire Podiceps cristatus Great Crested Grebe 492-1490 0.7-1.5 sionally prongs along

P. Red-necked Grebe 316-1270 0.7-1.4 grisegena length of the barbule. P. auritius Slavonian Grebe 300-500 0.7-1.6 Sulidae: The barbules are not pigmented, P. nigricollis Black-necked Grebe 213-450 0.7-1.7 but they possess many very well-developed

their entire These prongs along length. prongs

reach of 0.1 and a length over mm they are slightly swollen nodes or well-developed prongs always longer than the adjacent internodes. internodes is (21-29 per mm) and easily percep- They are slender, filamentous, and frequently tible. the nodes Usually are not pigmented, bifurcated, and they only slightly decrease in in except in Oceanodroma leucorhoa and often length towards the tips of the barbules. Hydrobates pelagicus. No villi at the basal cells. Phaethontidae: The barbules are not

and short their pigmented possess prongs along Table III entire length (21-25 per mm). Body weight (in g), length of barbules (in mm), and

in number of nodal structures (per mm barbule) Table IV Procellariiformes.

Body weight (in g) and length of barbules (in mm) in

Species body barbule N of Pelecaniformes.

weight length nodes

Species body barbule Fulmarus glacialis Northern Fulmar 535-1000) 0.7-1.1 25-29 weight length Calonectris diomedea Cory's Shearwater 500-1130) 0.6-1.0 21-26

Puffinus puffinus Manx Shearwater 310-565 0.6-1.0 22-27

Hydrobates pelagicus Storm Petrel 18-40 0.5-1.1 24-29 Phaethon Red-billed

Leach's Storm Oceanodroma aethereus Tropicbird 427-730 0.6-1.0 leucorhoa Petrel 29-57 0.5-1.0 23-27 Sula bassana Northern Gannet 1630-3610 0.5-1.0

Phalacrocorax

carbo Great Cormorant 1500-4900 0.7-1.2

P. aristotelis Shag 1470-2154 0.6-1.2 4. Pelecaniformes (figs. 6-7; table IV) Pelecanus Australian con-

Six species from five families (Phaethontidae, spicillatus Pelican 4000-13000 0.7-1.3

Sulidae, Phalacrocoracidae, Pelecanidae, and Fregata Magnificent magnificens Frigatebird 1061-1750 0.9-1.5 Fregatidae) have been examined. Range of

weights 427-13000 g.

— 5. Cic Description. The barbules are short (0.5- oniiformes (figs. 8-10; table V)

1.5 mm) and smoothly filamentous for most of Thirteen species from three families (Ardeidae, their length. No villi at the basal cells. In Ciconiidae, and Threskiornithidae) have been pigmentation of the pennulae and in length of examined. of 64-5000 Range weights g. the variation exists within this prongs some

— The barbules in order. Description. vary length

Pelecanidae The barbules from 0.8 3.0 Some exist and Fregatidae: to mm. differences

and swollen nodes between the families in the of are not pigmented no are examined, length

found. At the there minute the of tips are prongs barbules, degree pigmentation, presence

which sometimes extend the whole of and number of nodal along length prongs, structures per

No villi of the barbule. mm. at the basal cells.

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barbules rather than in both other Ciconiidae: The are long are more numerous per mm

(1.2-2.5 mm), slender, filamentous and not families. pigmented. Usually there are small,

the entire of 6. Phoenicopreroformes inconspicuous prongs along length (fig. 11)

which fewer in the barbule (11-14 per mm), are consists of This order a single family number than in both other families. (Phoenicopteridae). Two species have been Ardeidae: The barbules are rather long (1.1- examined: Greater Flamingo Phoenicopterus ruber with 3.0 mm), very slender, filamentous, and Lesser Flamingo P. minor. Range of slightly enlarged nodal structures which can 1412-4400 weights g. often be counted. In Bubulcus, Ardeola, Egretta, and Nycticorax the barbules are not pigmented, Description. — The barbules are very short and minute be found. In and their some prongs can (0.5-1.2 mm) not pigmented. Along

and the barbules entire small found Ardea, Botaurus, Ixobrychus may length sprongs are (22-27 per be uniformly (or almost uniformly) pigmented mm), that are slightly longer than in

(pigment not collected into conspicuous spots) Ciconiiformes. Only distally some slightly

with minute be No villi the or not pigmented, prongs usually enlarged nodes may present. at present only distally. basal cells.

T able V 7. Anseriformes (figs. 12-14; table VI)

Body weight (in g) and length of barbules (in mm) of the Anatidae in Ciconiiformes. Thirty-eight species family

have been examined. Range of weights 163-

Species body barbule 15000 g. weight length

— rather Description. The barbules are

Botaurus stellaris Bittern 430-1940 1.3-2.0 short but less than 1.3 (0.5-2.0 mm, usually Ixobrychus in For and simple structure. the greater minutus Little Bittern 64-170 1.6-2.1 mm)

of their are thread-like. The Nycticorax part length they nodes the distal nycticorax Night Heron 339-1014 1.2-2.1 are undeveloped except at part

Ardeola ralloides Heron 180-370 1.1-2.2 number of Squacco of the barbule where a triangular Bubulcus ibis Cattle Egret 300-450 1.3-2.4 (but visible as heart-shaped under the Egretta garzetta Little Egret 280-614 1.1-1.9 nodes followed microscope) are found, by a E. alba Great White terminal slender The number of nodes may Egret 760-1680 1.2-3.0 tip. 1 in different Ardea cinerea Grey Heron 810-2300 1.2-2.5 differ considerably (from to 10)

A. Purple Heron 515-1650 1.2-2.5 value resides in this purpurea genera, but no diagnostic

Ciconia Black Stork 1.2-2.1 nigra 2400-3000 found character as large differences can be C. ciconia White Stork 2140-5000 1.3-2.5 The between feathers of a single bird. nodes Plegadis may sometimes be reduced and in that case a falcinellus Glossy Ibis 365-850 0.8-1.2 their Platalea few terminal pairs of prongs are taking

795-1960 0.9-1.3 leucorodia Spoonbill place. Pigmentation of the barbules is confined

to the nodes and varies in density from species

to species. The internodes are long (longer in

Threskiornithidae: The barbules are shorter geese than in ducks) and often show a con- than in both other families (0.8-1.3 mm), stout spicuous bending or kinking, usually most pro- and and nounced in No differences coarse, they are not pigmented. Along geese. significant their entire the barbules well- found in the of the barbules of the length possess are length

in Platalea and various three developed prongs (19-23 per mm species. However, large groups

in shorter than of the bar- 21-26 Plegadis), which are always can be distinguished when the part the adjacent internodes. The nodal structures bule is measured that shows nodal structures.

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Fig. 7. Northern Gannet Sula bassana; throat feather (105 x).

Fig. 8. White Stork Ciconia ciconia; under tail covert (105 x).

Fig. 9. Bittern Botaurus stellaris; under wing covert (42 x).

10. Platalea Fig. Spoonbill leucorodia; upper wing covert (42 x).

Fig. 11. Greater Flamingo Phoenicopterus ruber; breast feather (105 x).

Fig. 12. Pochard Aythya ferina; belly feather (105 x). Heart-shaped nodes at the tips of the barbules.

The barbules of ducks show nodal arrangement 8. (figs. 15-16; table VII)

for 10-35% of their length, those of geese for

those of for This order of birds of consists of 30-70%, and swans 55-85%. Only prey two

Shelducks Tadorna families and the ( ) form an ( Pandionidae).

intermediate group with 23-44%. No villi at the Seventeen species have been examined. Range

of 103-7500 basal cells. weights g.

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TableVI of the barbule, sometimes at the tips only, but

Body weight (in g) and length of barbules (in mm) usually only at the bases. Counting the nodes or

in Anseriformes. is difficult and sometimes prongs usually

impossible at magnifications up to 200 x . No Species body barbule

villi at the basal cells. weight length

Cygnus olor Mute Swan 5500-15000 0.8-1.1 Table VII C. columbianus Bewick's Swan 3300-9600 0.7-1.1

7000-14000 0.7-1.1 and of barbules in C. cygnus Whooper Swan Body weight (in g) length (in mm)

Anser fabalis Bean Goose 1500-4300 0.7-1.2 Accipitriformes.

A. brachyrhynchus Pink-footed Goose 1410-3350 0.7-1.4

A. White-fronted Goose 1150-3340 0.6-1.4 albifrons Species body barbule A. erythropus Lesser White- weight length fronted Goose 1310-2500 0.7-1.1

A. anser Greylag Goose 1980-4560 0.6-1.1 Pernis apivorus Honey Buzzard 360-1490 2.5-5.8 A. indicus Bar-headed Goose 2000-3200 0.7-1.3 Milvus migrans Black Kite 500-1186 2.0-3.6 Branta canadensis Canada Goose 1100-7570 0.8-1.3 M. milvus Red Kite 757-1600 1.8-3.0 B. leucopsis Barnacle Goose 1020-2650 0.9-2.0 Haliaeetus B. bernicla Brent Goose 850-2220 0.6-1.1

albicilla White-tailed e 3019-7500 1.8-4.1 B. ruficollis Red-breasted Goose 1000-1625 0.7-1.5

Tadorna ferruginea Ruddy Shelduck 925-1600 0.6-1.5 Terathopius

T. tadorna Shelduck 500-1650 0.6-1.3 ecaudatus 1820-2950 1.8-2.1

Aix galericulata Mandarin Duck 428-725 0.8-1.7 Circus aerugi- 400-1090 Anas penelope Wigeon 0.6-1.8 Marsh Harrier 2.3-3.7 nosus 320-1370

A. Gadwall 470-1300 0.5-1.2 strepera C. Hen Harrier 200-740 2.4-4.0 cyaneus

A. crecca Teal 163-500 0.7-1.7 C. macrourus Pallid Harrier 235-604 2.3-3.4 A. platyrhynchos Mallard 500-1800 0.7-2.0 C. pygargus Montagu's Harriei:r 227-445 2.3-3.1 A. acuta Pintail 400-1444 0.7-1.1 Melierax Dark Chanting A. querquedula Garganey 250-600 0.6-1.1 metabates Goshawk 488-852 1.5-2.2 A. discors Blue-winged Teal 188-590 0.7-1.4 Goshawk 517-2054 1.9-4.8 A. clypeata Shoveler 300-1100 0.6-1.1 Accipiter gentilis

Netta rufina Red-crested Pochard 694-1550 0.6-1.6 A. nisus Sparrowhawk 103-346 1.8-3.8

Aythya ferina Pochard 467-1300 0.7-1.2 Buteo buteo Buzzard 427-1364 1.8-4.1

A. Ferruginous Duck 400-740 0.6-1.1 nyroca B. lagopus Rough-legged A. fuligula Tufted Duck 335-1400 0.6-1.0 Buzzard 600-1660 1.9-3.4 A. marila Scaup 690-1372 0.6-1.1 1572-4850 2.4-3.8 Aquila rapax Steppe Eagle Somateria A. chrysaetos Golden Eagle 2840-6665 2.0-3.5 mollissima Eider 1150-2900 0.5-0.9 Pandion Clangula hyemalis Long-tailed Duck 453-955 0.5-0.8 haliaetus Osprey 1120-2050 1.0-1.7 Melanitta nigra Common Scoter 600-1610 0.5-1.3

M. fusca Velvet Scoter 850-2104 0.5-0.8

Bucephala clangula Goldeneye 496-1400 0.7-1.2

Mergus albellus Smew 500-950 0.5-0.9 9. Falconiformes (figs. 17-18; table VIII) M. senator Red-breasted

Merganser 644-1360 0.5-1.2 Nine of the Falconidae have been M. species family merganser Goosander 860-2160 0.8-1.6 of Oxyura leuco- examined. Range weights 90-2100 g.

cephala White-headed Duck 400-900 0.7-1.1

Description. — The barbules are rather long

(1.1-3.4 mm) and always clearly divided along

— their entire into and Description. The barbules are very long length slightly enlarged

and slender and and slender and (1.0-5.8 mm), not pigmented heavily pigmented nodes, very

(only in the Bateleur Terathopius ecaudatus wavy internodes. In this they are completely

A sub- from the heavily pigmented barbules are found). different Accipitriformes. The number

division of the barbules is often hardly percepti- of nodes can always be counted and varies from

the nodes 11 24. birds tend ble, as are only very slightly enlarged to Larger to possess longer

short barbules with fewer nodes than smaller (10-20 per mm). They possess prongs, per mm

in but small be which are asymmetrical most cases. These birds, the differences are too to

sometimes the entire No found in this prongs occur along length diagnostic. prongs are group

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Fig. 13. Barnacle Goose Branta leucopsis; back feather (105 x). Barbules show characteristic kinking.

Fig. 14. Whooper Swan Cygnus cygnus; neck feather (105 x).

15. Goshawk Fig. Accipiter gentilis; upper wing covert (42 x).

Fig. 16. Buzzard Buteo buteo; breast feather (130 x).

Fig. 17. Hobby Falco subbuteo; breast feather (85 x).

Fig. 18. Red-footed FalconFalco vespertinus; breast feather (85 x).

200 No villi the — The barbules (at magnifications up to x ). at Description. are very long basal cells. (1.6-5.5 mm) and they are always clearly

divided along their entire length into pigmented

nodes and filamentous internodes. At their 10. Galliformes (figs. 19-20; table IX) the barbules proximal part possess poorly

from families Thirteen species two developed nodes, which, however, soon

and been increase in width and (Tetraonidae Phasianidae) have develop a typical ring-like

of 52-6500 of these become examined. Range weights g. shape. Frequently, some rings

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Table VIII 11. (figs. 21-23; table X)

Body weight (in g), length of barbules (in mm), and Fifteen species from five families (Turnicidae, number of nodes (per mm barbule) in Falconiformes. Rallidae, Aramidae, Gruidae, and Otididae)

N Species body barbule of have been examined. Range of weights 28- weight length nodes 18000 g.

Fako naumanni Lesser Kestrel 90-208 1.2-2.1 13-22

— The barbules from Description. vary F. tinnunculus Kestrel 113-314 1.2-2.6 13-24

F. American Kestrel 95-130 1.1-2.5 short to sparverius 13-23 extremely (0.4 mm) extremely long

F. Red-footed vespertinus (5.9 mm). Large differences exist between the Falcon 130-197 1.4-2.4 13-23 families that were studied. In none of them villi F. columbarius Merlin 125-300 1.4-2.6 14-23 the basal cells. F. subbuteo Hobby 131-340 1.3-2.7 14-21 are present at

F. eleonorae Eleonora's Turnicidae: The barbules are short (0.6-1.3 Falcon 270-510 1.4-2.6 13-18 mm) and subdivided along their entire length F. rusticolus Gyr Falcon 800-2100 1.5-3.4 11-17 but nodes F. peregrinus Peregrine 330-1333 1.8-3.0 12-19 by pigmented, hardly enlarged (23-

29 difficult per mm, to count).

Rallidae: The barbules are rather short (0.4-

1.7 mm) and subdivided into heavily detached and slide along the slender internodes pigmented nodes (15-32 per mm) and short like into of rings on a wire, breaking up groups The is in internodes. pigment mainly present 2-10 (multiple nodes; fig. 20). Toward the tips the nodes and the distal of the part internodes. of the barbules, the ring-like structure is again The minute prongs at the nodes and the prox- lost, and the nodes become simply swollen. imal part of the internodes are more or less Larger birds tend to have longer barbules and unpigmented. Towards the base of the barbules fewer nodes per mm. Multiple nodes are not nodes whereas further usually 2-4 are enlarged, always present in great numbers and may be along the barbule and in the tip region they are difficult to find. No villi at the basal cells. only slightly swollen and often difficult to

Table IX Table X

Body weight (in g), length of barbules (in mm), and Body weight (in g), length of barbules (in mm), and number of nodes (per mm barbule) in Galliformes (multi- number of nodes (per mm barbule) in Gruiformes. ple nodes not included).

Species body barbule N of barbule N of Species body weight length nodes weight length nodes

Turnix sylvatica Andalusian

Bonasa bonasia Hazel Grouse 278-500 1.8-3.2 20-28 Hemipode 29-70 0.6-1.3 23-29

Lagopus lagopus Willow/Red Rallus aquaticus Water 74-190 0.6-1.1 26-32

Crake 47-147 0.5-1.3 22-28 Grouse 400-908 1.7-3.3 20-29 Porzana porzana Spotted

P. Little Crake 30-72 0.5-1.2 L. mutus Ptarmigan 243-610 2.0-3.9 14-26 parva 25-30 P. Baillon's Crake 28-60 0.5-1.2 26-30 Tetrao tetrix Black Grouse 615-1750 2.8-3.8 13-24 pusilla

Crex crex Corn Crake 95-210 0.5-1.4 22-29 T. urogallus Capercaillie 1370-6500 2.2-5.5 15-26 Gallinula Callipepla California chloropus 140-493 0.7-1.5 19-29 californica Quail 130-207 1.7-3.0 20-34 Porphyrio Alectoris chukar Chukar 365-595 2.3-3.6 18-27 porphyrio Purple Coot 325-1000 0.6-1.7 15-19 A. rufa Red-legged Gallicrex cinerea Watercock 200-510 0.4-1.3 21-26 Partridge 240-547 1.9-3.0 23-31 Fulica atra Coot 300-1460 0.6-1.4 18-24 Francolinus Grus Common 3000-7000 grus Crane 1.0-2.2 francolinus Black Francolin 227-570 2.5-3.3 22-28 Anthropoides Demoiselle Perdix perdix Partridge 310-480 2.1-4.0 22-30 virgo Crane 1985-3060 0.8-2.2

Coturnix coturnixx 52-155 1.8-2.6 25-35 Quail Tetrax tetrax Little Bustard 525-1000 1.7-3.8 C. japonica Japanese Quail 1.6-2.4 25-35 Chlamydotis

Phasianus undulata Houbara 1100-1375 1.9-4.9

colchicus Pheasant 500-2015 2.5-4.1 15-23 Otis tarda Great Bustard 3200-18000 2.0-5.9

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Fig. 19. Black Grouse Tetrao tetrix; breast feather (85 x).

Fig. 20. Black Grouse Tetrao tetrix; breast feather (325 x). Barbules with multiple nodes.

Fig. 21. Andalusian HemipodeTurnix sylvatica; breast feather (105 x).

tail Fig. 22. Spotted Crake Porzana porzana; under covert (105 x). Fig. 23. Watercock Gallicrex cinerea; breast feather (105 x).

Fig. 24. Oystercatcher Haematopus ostralegus; thigh feather (130 x).

count. This reduction in the size of the nodes form of almost unmodified threads, which, takes distance 1-3 show place quite abruptly over a of however, at higher magnification (200 x ) internodes and is always more pronounced in minute prongs at the nodes; two of a pair of

birds tend have size. The small one of both vanules. Larger to prongs are usually of unequal fewer nodes than smaller birds. nodes and be counted. per mm prongs cannot

The barbules medium The Gruidae: are of length Otididae: barbules are extremely long

(0.8-2.2 mm), not pigmented, and have the (1.7-5.9 mm), not pigmented, and only

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inconspicuously subdivided by nodes (but not

towards the bases some by prongs). Only very Species body barbule AT of nodes weight length nodes slightly enlarged (but unpigmented) are

few in number be C. hiaticula Plover 27-81 0.6-1.5 20-26 visible, which are too to Ringed C. vociferus Killdeer 65-90 0.9-1.5 22-27 counted. C. alexandrinus Kentish Plover 32-69 0.5-1.3 23-32

C. mongolus Lesser Sand Plover 39-126 0.8-1.3 22-27

C. leschenaultii Greater Sand Plover 60-120 0.7-1.3 21-29 12. Charadriiformes (figs. 24-33; table XI) C. asiaticus Caspian Plover 60-91 0.7-1.3 22-34

Eudromias morinellus Dotterel 86-142 0.8-2.2 19-30

Sixty-eight species from nine families Pluvialis apricaria Golden Plover 88-239 0.6-1.7 19-26 P. squatarola Grey Plover 105-335 0.6-1.9 18-24 (Haematopodidae, Recurvirostridae, Glareoli- Hoploplerus spinosus Spur-winged dae, Charadriidae, Scolopacidae, Ster- Lapwing 127-170 0.9-1.3 18-22 Chettusia gregaria Sociable Lapwing 180-260 0.7-1.7 16-21 corariidae, Laridae, Sternidae, and Alcidae) C. leucura White-tailed

have been examined. Range of weights 14-2700 Lapwing 99-198 0.7-1.4 22-27 Vanellus vanellus Lapwing 112-330 0.4-1.5 24-35

g- Calidris canutus Knot 82-230 0.5-1.4 26-35

C. alba Sanderling 41-88 0.5-1.2 25-32

Description. — The length of the barbules C. minuta Little Stint 14-44 0.5-1.2 24-34

C. temminckii Temminck's Stint 15-35 0.6-1.6 23-33 0.4 varies between and 3.4 mm. Large dif- C. ferruginea Curlew Sandpiper 32-100 0.5-1.2 26-35

ferences exist between the nine families in the C. alpina Dunlin 26-74 0.5-1.4 29-39 25-33 Philomachus pugnax Ruff 67-254 0.5-1.4 length of the barbules, degree of pigmentation, Lymnocryptes minimus Jack Snipe 43-92 0.5-1.3 30-37

of and number of nodal struc- Gallinago gallinago Common Snipe 76-227 0.5-1.4 24-33 presence prongs, G. media Great Snipe 140-265 0.6-1.5 19-30 tures mm. No villi are present at the basal per Scolopax rusticola Woodcock 198-520 1.1-3.4 14-18 cells. Limosa limosa Black-tailed Godwit 160-500 0.5-1.3 26-35

L. lapponica Bar-tailed Godwit 147-373 0.5-1.6 23-29 The barbules from Haematopodidae: vary Numenius phaeopus Whimbrel 227-660 0.5-1.0 27-34

N. Curlew 410-1280 0.5-1.1 25-31 0.7 to 1.7 mm and are subdividedby nodes(17- arquata Tringa erythropus Spotted Redshank 97-205 0.5-1.2 25-31 23 which are not 25-33 per mm) pigmented (thus, T. totanus Redshank 78-166 0.6-1.4

T. Marsh 36-120 0.5-1.5 26-34 completely different from Lapwing). Towards stagnatilis Sandpiper T. nebularia Greenshank 134-283 0.5-1.3 22-28 the of nodes tips the barbules, the gradually T. ochropus Green Sandpiper 50-112 0.6-1.4 25-31

T. glareola Wood Sandpiper 34-89 0.6-1.2 26-35 become smaller and less conspicuous, and Actitis hypoleucos Common Sandpiper 28-73 0.6-1.6 24-30 often show short 26-32 distally they prongs. Arenaria interpres Turnstone 73-195 0.5-1.2

Phalaropus lobatus Red-necked Recurvirostridae: The barbules from vary Phalarope 25-48 0.5-1.1 25-34 0.6 1.5 and 30-77 0.5-1.1 25-33 to mm are always subdivided by P. fulicarius Grey Phalarope Stercorarius pomarinus Pomarine Skua 469-917 0.6-1.1 18-27 nodes sometimes usually unpigmented (but S. parasiticus Arctic Skua 297-644 0.6-1.1 18-27

pigmented and situated at the bases of the bar- S. longicaudus Long-tailed Skua 195-444 0.6-1.2 20-27 S. skua Great Skua 600-2040 0.5-1.0 20-26 which minute bules) may possess prongs. Larus minutus Little Gull 80-150 0.5-1.0 19-24

Glareolidae: The barbules from 0.5 L. ridibundus Black-headed Gull 116-390 0.5-1.3 16-22 vary to 300-586 0.5-1.3 16-22 L. canus Common Gull 1.3 and subdivided mm they are always by L. fuscus Lesser Black-

backed Gull 534-1180 0.6-1.2 17-22 pigmented nodes (19-27 per mm). 600-1800 0.7-1.2 16-21 L. argentatus Herring Gull L. hyperboreus Glaucous Gull 1151-2700 0.5-1.2 18-22 Table XI L. marinus Great Black-

backed Gull 996-2275 0.7-1.4 15-20 Body weight (in g), length of barbules (in mm), and Rissa tridactyla Kittiwake 210-610 0.5-1.2 18-23 number of nodal structures (per mm barbule) in Gelochelidon nilotica Gull-billed Tern 154-290 0.6-1.1 19-25 Charadriiformes. Sterna sandvicensis Sandwich Tern 174-330 0.6-1.1 20-25

S. hirundo Common Tern 76-175 0.6-1.1 18-26

Species body barbule AT of S. paradisaea Arctic Tern 87-142 0.6-1.1 19-24 nodes weight length S. albifrons Little Tern 31-60 0.5-1.0 22-29

Chlidonias hybrida Whiskered Tern 61-94 0.6-1.2 19-24 Haematopus ostralegus Oystercatcher 284-745 0.7-1.7 17-23 C. nigra Black Tern 51-77 0.7-1.2 20-24 Himantopus Uria aalge Guillemot 612-1200 0.4-0.8 Stilt 132-289 0.6-1.5 17-26 himantopus Black-winged U. lomvia Briinnich's Recurvirostra Avocet 231-435 0.6-1.4 17-24 avosetta Guillemot 604-1200 0.4-0.9 Glareola Pratincole 60-95 0.5-1.3 19-27 pratincola Alca torda Razorbill 450-920 0.4-0.9 G. nordmanni Black-winged Cepphus grylle Black Guillemot 312-615 0.6-1.1 Pratincole 87-105 0.6-1.2 20-27 Fratercula arctica Puffin 290-586 0.4-1.0

Charadrius dubius Little Ringed Plover 26-54 0.5-1.2 23-29

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Fig. 25. Avocet Recurvirostra avosetta; breast feather (85 x).

Fig. 26. Pratincole Glareola pratincola; belly feather (205 x).

Fig. 27. Golden Plover Pluvialis apricaria; breast feather (85 x).

Fig. 28. Ringed Plover Charadrius hiaticula; belly feather (205 x).

Fig. 29. Dunlin Calidris alpina; breast feather (85 x).

Fig. 30. Long-tailed Skua Stercorarius longicaudus; mantle feather (85 x).

Charadriidae: The barbules from 0.4 basal barbules. Considerable differences in the vary to

and of exist. In the Golden 2.2 mm they are always clearly subdivided extent pigmentation

Pluvialis by nodes (16-35 per mm), which may be Plover apricaria some unpigmented

nodes found the of the pigmented as well as unpigmented. Prongs are are at tips barbules only

while the all not found within this family (at magnifications remaining nodes are pigmented. In

the between 50 and 500 x ). Pigmented nodes are Charadrius usually only the nodes at basal

of the always found at the basal portion of the most part most basal barbules are pigmented.

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Table XII Scolopacidae: The barbules are rather short

reach of barbules (0.5-1.6 mm; only in Scolopax they up to Body weight (in g), length (in mm), and

3.4 such number of nodal structures (per mm barbule) in mm). In some genera, as Scolopax, Pteroclidiformes. Gallinago, Lymnocryptes, and Phalaropus the bar- bules are conspicuously subdivided by nodes Species body barbule TV of

weight length nodes (14-37 per mm) which are always pigmented.

In the remaining species, pigmented as well as Pterocles alchata Pin-tailed Sand-

200-340 1.6-3.0 12-17 nodes grouse unpigmented occur (22-39 mm), per P. orientalis Black-bellied Sand- which occasionally possess minute prongs. In grouse 410-650 1.6-4.8 12-17 Syrrhaptes paradoxus Pallas's Sandgrouse 254-340 1.7-4.2 11-15 Numenius the nodes are usually not pigmented, but In pigmented ones may occur. Calidris,

Tringa, Limosa, Arenaria, and Philomachus the nodes but 14. Columbiformes table are usually pigmented, especially (fig. 35; XIII) towards the tips of the barbules unpigmented This order consists of a single family (Colum- nodes occur as well. bidae). Five species have been examined. Stercorariidae: The barbules short are very of 74-739 Range weights g. and subdivided (0.5-1.2 mm) they are by

nodes minute — The barbules unpigmented or prongs (18-27 Description. are very long

the basal number of per mm). (1.1-5.1 mm); on part a

Laridae: The barbules short and nodes are along very large, flattened, plate-like are

of subdivided found: 3-8 of full then number of most their length by usually size, a

and rather nodes smaller and less unpigmented inconspicuous conspicuous ones, decreasing which often possess prongs. Always only the in size until they almost completely disappear,

basal barbules 3-8 and the barbule most possess enlarged the whole distal portion of being

nodes filamentous with minute heavily pigmented proximally. smoothly or very

Sternidae: This resembles the swollen nodes with minute group closely (occasionally

the gulls. The barbules vary from 0.5 to 1.2 mm prongs). Only the most basal barbules of

there nodal and are 18-29 structures per mm. feather possess expanded, quadrilobed nodes

Alcidae: The barbules short their whole are extremely along length (10-18 per mm).

and is and confined the (0.4-1.1 mm) they are faintly subdivided Pigmentation slight to

indistinct nodes nodes. the examined by or well-developed prongs, Among species no

the which are most prominent distally. Often an diagnostic differences are found in length of

diffuse barbules the number inconspicuous and pigmentation is the or of nodes per mm.

No villi cells. present. at the basal

13. Pteroclidiformes (fig. 34; table XII)

Table XIII This order consists of a single family Body weight (in g), length of barbules (in mm), and (Pteroclididae). Three species have been number of nodes (per mm barbule) in Columbiformes. of examined. Range weights 200-650 g.

Species body barbule N of — The Description. barbules are very long weight length nodes (1.6-4.8 mm) and along their entire length divided into nodes which often Columba livia Rock Dove/ (11-17 per mm)

Feral Dove 194-570 1.2-4.4 11-16 minute and both possess prongs, internodes, C. Stock Dove 217-567 10-16 oenas 1.1-4.7 3-5 nodes unpigmented. Orily proximally are C. palumbus Wood Pigeon 258-739 1.2-4.6 10-16 slightly enlarged and rather conspicuous, fur- Streptopelia decaocto Collared 12-18 ther the Dove 113-243 1.2-4.8 along barbules they are often hard to S. turtur Turtle Dove 74-178 1.3-5.1 11-17 count. No villi at the basal cells.

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Fig. 31. Little Gull Larus minutus; breast feather (85 x).

Fig. 32. Kittiwake Rissa tridactyla; belly feather (205 x).

Fig. 33. Razorbill Alca torda; breast feather (205 x).

Fig. 34. Pallas’s Sandgrouse Syrrhaptes paradoxus; belly feather (205 x).

Fig. 35. Wood Pigeon Columba palumbus; mantle feather (85 x).

Fig. 36. Budgerigar Melopsittacus undulatus; belly feather (105 x).

15. Psittaci formes table nodes which (fig. 36; XIV) (12-34 per mm) are enlarged prox-

imally but minute distally. Larger birds tend to Ten species from three families (Loriidae, fewer nodes than smaller birds. possess per mm Cacatuidae, and Psittacidae) have been nodes well Deeply pigmented as as examined. of 33-1286 Range weights g. be in first unpigmented nodes can found; the

— The barbules the barbules resemble those of Description. are long (0.8- case may the

3.5 and but slender and mm) possess globular or triangular Passeriformes, they are more

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sometimes show bend- Strix aluco is No villi wavy. The internodes a pigmentation quite heavy.

No cells. ing or kinking. villi at the basal at the basal cells.

Table XIV T able XV

Body weight (in g), length of barbules (in mm), and Body weight (in g), length of barbules (in mm), and

number of nodes (per mm barbule) in Psittaciformes. number of nodes (per mm barbule) in Strigiformes.

Species body barbule Not Species body barbule N of weight length nodes weight length nodes

Melopsittacus Tyto alba Barn Owl 206-660 1.5-3.7 8-15 undulatus Budgerigar ca. 33 0.8-1.6 23-34 Otus Scops Owl 50-145 1.6-3.1 13-23 Nymphicus hollandicus Cockatiel 72-113 1.4-2.8 13-21 scops Owl Cacatua sulphurea Sulphur-crested Bubo bubo Eagle 2000-3260 1.6-6.1 10-19 Cockatoo 320-358 1.4-3.5 14-23 Nyctea scandiaca Snowy Owl 710-2950 2.0-4.3 10-15 Psittacus erithacus Parrot 200-300 1.3-2.6 17-25 Grey Glaudicium Lorius domicellus 1.5-2.3 16-24 Purple-naped Lory passerinum Pygmy Owl 55-79 1.0-2.4 15-26 Agapornis taranta Black-winged Athene noctua Little Owl 85-271 1.2-2.9 15-24 Lovebird ca. 38 1.1-1.8 24-33 Strix aluco Tawny Owl 264-695 1.5-4.1 12-21 Loriculus stigmatus Celebes Hanging

Parrot 37-49 1.4-2.0 20-30 Asio otus Long-eared

Poicephalus rueppellii Ruppell's Parrot 1.5-2.3 17-28 Owl 151-378 1.7-5.2 10-17

P. senegalus Senegal Parrot 1.2-2.5 19-27 A. flammeus Short-eared

Ara ararauna Blue and Yellow Owl 229-500 2.0-4.2 10-17 Macaw 1157-1286 1.5-2.9 12-22 Aegolius Tengmalm's

funereus Owl 109-197 1.2-2.8 14-30

16. Cuculiformes (fig. 37)

18. Caprimulgiformes (fig. 40) Two species of the family Cuculidae have been

examined. of 63-220 Three of the have Range weights g. species family Caprimulgidae

been examined: Nightjar Caprimulgus europaeus,

— The barbules Description. are very long Red-necked Nightjar C. ruficollis, and Egyptian in (1.4-3.2 mm Great Spotted Cuckoo Clamator Nightjar C. aegyptius. Range of weights and 1.5-5.0 Cuculus glandarius mm in Cuckoo 45-100 g. and slender. have canorus) very They globular

the — barbules of medium nodes (8-18 per mm); those towards base Description. The are

are large, whereas more distally they are length (1.3-3.0 mm) and at low magnifications

minute. The internodes dark and are extremely long and (50 x) they appear as heavily

and show kink- slender, they sometimes a slight pigmented threads, resembling those of

ing. No villi at the basal cells. Apodiformes. At higher magnification (200 x ),

the subdivision into nodes and internodes

17. Strigiformes (figs. 38-39; table XV) becomes perceptible, but even then only 2-5

the of basal nodes are visible. Thus, number This order consists of two families (Tytonidae nodes be estimated can only (14-16 per mm). and Strigidae) from which ten species have No villi at the basal cells. been examined. of 50-3260 Range weights g.

— The Description. barbules are very long 19. Apodiformes (fig. 41)

and (1.0-6.1 mm) are divided by pigmented Two species of the family Apodidae have been nodes their entire along length (8-30 per mm). examined: Swift Apus apus and Alpine Swift A. The nodes show an abrupt reduction in size: 2- melba. of 22-120 Range weights g. nodes 6 proximal are enlarged, the remaining

— rather ones are small and longitudinally shaped. The Description. The barbules are

degree of pigmentation varies from species to short (0.7-1.7 mm). At low magnification

The Owl scandiaca shows species. Snowy Nyctea (50 x ) they appear as dark, heavily pigmented

whereas sub- little pigmentation, in the Tawny Owl threads; at higher magnification (200 x ), a

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Fig. 37. Great Spotted Cuckoo Clamator glandarius; breast feather (105 x)

Fig. 38. Barn Owl Tyto alba; neck feather (85 x).

39. Fig. Snowy Owl Nyctea scandiaca; upper wing covert (85 x). Fig. 40. Red-necked Nightjar Caprimulgus ruficollis; breast feather (85 x).

feather Fig. 41. Swift Apus apus; breast (85 x).

Fig. 42. Kingfisher Alcedo atthis; breast feather (85 x).

division into nodes and internodes becomes 20. Coraciiformes (figs. 42-43; table XVI)

visible. The nodes minute but possess prongs,

nodes difficult Both Four from four or prongs are very to count. species families (Alcedinidae,

nodes and internodes No and are partly pigmented. Meropidae, Coraciidae, Upupidae) have

villi at the basal cells. been examined. of Range weights 23-183 g.

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Fig. 43. Hoopoe Upupa epops; breast feather (85 x).

Fig. 44. Black Woodpecker Dryocopus martius; belly feather (105 x).

Fig. 45. Lesser Spotted Woodpecker Dendrocopos minor; breast feather (165 x). Curved and scimitar-shaped villi at the

basal cells.

Fig. 46. Skylark Alauda arvensis; breast feather (105 x).

Corvus breast Villi basal Fig. 47. Hooded Crow corone cornix; feather (205 x). at the cells.

48. Hooded Crow Corvus breast feather Villus basal cell Fig. corone cornix; (325 x). at (arrow).

— barbules the Description. The are of medium barbules. Among four species examined, a

length (0.8-2.9 mm) and they are clearly tendency seems to exist that larger birds possess

divided into fewer than smaller No villi pigmented nodes (14-32 per mm) nodes per mm ones.

and unpigmented internodes. The nodes at the basal cells.

slightly decrease in size towards the tips of the

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Table XVI suborders, of which in Europe only the largest

Body weight (in g), length of barbules (in mm), and (Oscines) is found. Some 100 species have been

number of nodes in Coraciiformes. (per mm barbule) examined, belonging to 22 families. Range of

4-1560 weights g. Species body barbule N of

nodes weight length — The of medium Description. barbules are

but than length (0.5-3.3 mm, usually shorter 2 Alcedo atthis Kingfisher 23-46 0.8-1.6 21-32

are subdivided into Merops apiaster Bee-eater 37-60 0.9-1.4 21-26 mm). They clearly enlarged

Coracias garrulus Roller 107-183 1.0-1.8 14-24 and pigmented nodes (16-55 per mm) and

Upupa epops Hoopoe 41-91 1.6-2.9 19-24 unpigmented internodes. The longest barbules

the are found in families Turdidae (0.5-3.3

mm), Corvidae (0.6-2.7 mm), and Alaudidae 21. Piciformes table (figs. 44-45; XVII) (0.6-2.2 mm); in the remaining families they

from 0.5-1.6 mm. At the basal cells villi Eight species of the family Picidae have been range which differ in from those examined. of 23-317 are present, shape Range weights g. found in Piciformes by being blunt, knobbed,

— barbules of medium Description. The are instead of recurved or finger-like, or sharply length (0.6-2.5 mm) and along their entire pointed. length they are clearly divided into pigmented

Table XVIII nodes (21-39 per mm) and unpigmented inter-

nodes. towards the tip the nodes Only slightly Body weight (in g), length of barbules (in mm), and number There decrease in size. is a tendency that larger of nodes (per mm barbule) in Passeriformes.

birds possess fewer nodes per mm than smaller Species body barbule N of

nodes birds. At the basal cells curved or scimitar- weight length

villi which shaped are present usually are point- Melanocorypha ing in the direction of the barb. The length of calandra Calandra Lark 55-63 0.8-1.7 30-35 Galerida cristata Crested Lark 31-49 0.8-2.2 29-40 these villi from 0.02 to 0.22 mm. ranges Lullula arborea Wood Lark 20-40 0.7-1.7 28-42

Alauda arvensis Skylark 23-54 0.7-1.6 28-40

Eremophila alpestris Shore Lark 27-46 0.6-1.4 31-37

Riparia riparia Sand Martin 9-19 0.6-1.1 28-36 Table XVII Hirundo rustica Swallow 11-28 0.6-1.2 27-35

Delichon urbica House Martin 10-28 0.8-1.5 27-32 Body weight (in g), length of barbules (in mm), and Anthus campestris Tawny Pipit 16-27 0.5-1.3 26-35 number of nodes (per mm barbule) in Piciformes. A. trivialis Tree Pipit 15-28 0.5-1.1 33-41 A. pratensis Meadow Pipit 10-25 0.5-1.0 38-46 Species body barbule N of A. spinoletta Water Pipit 16-31 0.6-1.1 31-42 weight length nodes Motacillaflava Yellow Wagtail 11-26 0.7-1.4 29-38

M. cinerea Grey Wagtail 14-25 0.6-1.3 29-38 Jynx torquilla Wryneck 23-72 1.0-1.7 31-36 M. alba White Wagtail 15-30 0.5-1.0 36-42 Picus canus Grey-headed Bombycilla garrulus Waxwing 40-83 0.7-1.3 29-40 Woodpecker 98-162 0.9-1.5 29-36 Cinclus cinclus Dipper 49-100 0.6-1.3 26-34 P. viridis Green Woodpecker 101-250 1.0-2.1 27-36 Troglodytes Dryocopus martius Black Woodpecker 201-317 1.0-2.3 21-31 troglodytes Wren 4-14 0.6-1.4 38-53 Great Spotted Dendrocopos major Prunella modularis Dunnock 13-26 0.8-1.7 34-43 Woodpecker 53-110 0.8-2.5 24-30 Erithacus rubecula Robin 10-25 0.7-1.5 30-44 D. medius Middle Spotted Luscinia Woodpecker 54-85 1.0-1.9 27-36 megarhynchos Nightingale 12-27 0.6-1.3 30-43 D. minor Lesser Spotted Phoenicurus ochruros Black Redstart 13-19 0.5-1.3 34-45 Woodpecker 14-25 0.6-1.2 33-39 Saxicola rubetra Whinchat 13-24 0.5-1.2 34-42 Picoides Three-toed S. torquata Stonechat 12-19 0.5-1.3 33-40 tridactylus Woodpecker 51-80 0.8-1.7 24-35 Oenanthe oenanthe Wheatear 14-41 0.7-1.2 34-43

Zoothera dauma White's Thrush 100-190 1.0-3.3 22-33

Turdus torquatus Ring Ouzel 83-138 0.9-2.7 20-31

T. merula Blackbird 73-135 1.0-1.9 30-41

22. Passeriformes (figs. 46-48; table XVIII) T. pilaris Fieldfare 52-146 0.6-2.2 24-34 T. philomelos Song Thrush 51-107 1.0-2.6 24-35 T. iliacus Redwing 38-88 0.8-1.7 27-34 This order contains nearly half of the known T. viscivorus Mistle Thrush 95-167 1.1-3.0 16-31 It species of birds. is divided into several Cettia cetti Cetti's Warbler 10-18 0.5-1.1 41-55

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Table XVIII (continuation)

Species body barbule AT of Species body barbule N of

weight length nodes weight length nodes

Locustella naevia Grasshopper Plectrophenax nivalis Snow Bunting 22-50 0.7-1.1 36-50

Warbler 11-16 0.6-1.3 35-44 Emberiza citrinella Yellowhammer 18-40 0.7-1.2 32-42

L. luscinioides Savi's Warbler 12-26 0.7-1.6 28-35 E. hortulana Ortolan Bunting 15-33 0.5-1.2 29-38

Acrocephalus E. pusilla Little Bunting 13-16 0.5-1.3 29-36

palustris Marsh Warbler 9-17 0.5-1.0 37-46 E. schoeniclus Reed Bunting 15-28 0.7-1.4 37-46

A. schoenobaenus Sedge Warbler 8-18 0.5-1.3 36-43 Miliaria calandra Corn Bunting 34-64 0.6-1.3 36-46

A. arundinaceus Great Reed

Warbler 22-53 0.7-1.3 32-42

Hippolais icterina Icterine Warbler 8-16 0.6-1.2 31-41

Sylvia nisoria Barred Warbler 19-30 0.7-1.3 27-42

S. curruca Lesser Whitethroat 9-21 0.6-1.2 34-47 IDENTIFICATION KEY S. communis Whitethroat 8-23 0.5-1.3 33-46

S. borin Garden Warbler 12-28 0.5-1.2 35-46

S. atricapilla Blackcap 11-27 0.5-1.4 37-45 is recommended It strongly to use this key only Phylloscopus Yellow-browed after the of the inornatus Warbler 4-8 0.6-1.1 38-45 studying previous description

P. sibilatrix Wood Warbler 6-14 0.5-1.0 35-45 characters of the 22 orders of birds examined. P. collybita ChifTchafT 5-11 0.5-0.9 36-46 The will identification if some P. trochilus Willow Warbler 5-13 0.5-1.0 39-50 key only permit

Regulus regulus Goldcrest 4-7 0.6-1.1 40-51 in coherent barbs are present the sample. When R. ignicapillus Firecrest 4-9 0.5-1.0 38-49 detached barbules are found, the iden- Muscicapa striata Spotted Flycatcher 10-20 0.6-1.2 34-44 only

Ficedula Red-breasted parva tification procedure will have to be stopped if Flycatcher 7-14 0.5-1.0 40-50 between barbules must be made. F. hypoleuca Pied Flycatcher 9-19 0.5-1.1 32-46 comparisons Panurus biarmicus Bearded Tit 12-18 0.5-1.2 38-46 that small is In the case only a very sample Aegithalos caudatus Long-tailed Tit 5-11 0.5-1.2 40-49 available, it not always be certain that Parus palustris Marsh Tit 7-14 0.6-1.5 34-44 may

P. montanus Willow Tit 7-12 0.5-1.0 36-48 barbules It be in downy are present. must kept P. cristatus Crested Tit 8-13 0.6-1.1 44-53 mind that barbules from the P. ater Coal Tit 7-16 0.6-1.1 39-52 originating pen-

P. caeruleus Blue Tit 9-16 0.6-1.1 43-52 naceous portion of the feather cannot be iden-

P. major Great Tit 14-22 0.6-1.2 38-47 tified with the help of this key. Some characters Sitta europaea Nuthatch 17-28 0.6-1.1 33-43

Certhia Short-toed for certain are diagnostic groups when only one brachydactyla T 7-14 0.5-1.3 37-50 reecreeper of example is found (such as the occurrence Oriolus oriolus Golden Oriole 52-96 0.7-1.6 21-31

Lanius collurio Red-backed Shrike 23-38 0.9-1.6 29-35 multiple nodes in Galliformes), but in other L. excubitor Great Grey Shrike 31-81 0.9-1.5 27-34 cases (such as the occurrence of villi at the basal L. senator Woodchat Shrike 21-45 0.7-1.4 26-36 in Piciformes it is Garrulus glandarius Jay 121-199 1.2-2.5 25-33 cells and Passeriformes) Pica pica Magpie 131-300 0.6-1.9 27-39 recommended to look for several examples to Nucifraga artifacts with caryocatactes Nutcracker 110-200 0.8-1.4 27-34 make sure that no interfere a cor-

Corvus monedula Jackdaw 123-281 0.8-1.6 28-40 rect identification. C. frugilegus Rook 225-595 1.0-2.0 25-30

C. corone corone Carrion Crow 322-695 1.0-2.4 23-34 Barbules 2 1. possess prongs C. c. cornix Hooded Crow 440-611 0.9-2.6 26-36

— Barbules lack 3 C. albus Pied Crow 474-612 0.8-2.1 21-29 prongs

2. Barbules nodes C. corax Raven 798-1560 1.0-2.2 21-29 possess triangular (heart-shaped)

Sturnus vulgaris Starling 49-122 0.6-1.3 31-41 distally 4 Passer domesticus House Sparrow 19-37 0.9-1.6 28-38 — Barbules without triangular nodes distally 5 P. montanus Tree Sparrow 15-29 0.6-1.3 32-40 3. Barbules nodes possess triangular (heart-shaped) Fringilla coelebs Chaffinch 15-39 0.5-1.4 33-44 4 F. montifringilla Brambiing 15-37 0.6-1.2 35-43 distally

Serinus serinus Serin 9-14 0.6-1.1 34-43 — Barbules without triangular nodes distally 12 S. canaria Canary 8-17 0.5-1.0 42-52 4. Barbules with triangular (heart-shaped) nodes distally: Carduelis chloris Greenfinch 20-37 0.7-1.1 35-45 ANSERIFORMES C. carduelis Goldfinch 12-22 0.6-1.2 36-46

- nodes of C. cannabina Linnet 16-24 0.7-1.0 35-44 along <40% barbule: DUCKS

C. Twite 13-21 0.7-1.4 35-43 - nodes flavirostris along 40-60% of barbule: GEESE

C. Common 9-23 0.7-1.4 43-52 flammea Redpoll - nodes along >60% of barbule: SWANS Loxia curvirostra Crossbill 24-48 0.7-1.3 35-44 5. Prongs longer than adjacent internodes: Pyrrhula pyrrhula Bullfinch 16-36 0.5-1.4 40-49 SULIDAE C. coccothraustes Hawfinch 41-70 0.6-1.2 28-39

— shorter internodes 6 Calcarius lapponicus Lapland Bunting 16-36 0.6-1.1 38-47 Prongs than adjacent

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entire of barbules, 6. At low magnification (50 x ) barbules clearly sub- 20. Nodes along length not plate-like divided into enlarged nodes and internodes 7 in shape 21

— At low nodes difficult — Nodes flattened and in magnification (50 x ) very to plate-like shape; only at most

discern 9 basal barbules reaching tip of barbule, but usually not

7. In most barbules (basalmost of barb) nodes rapidly present along entire length (the remaining part being

decrease in size over 2-6 basal internodes 8 smoothly filamentous):

— No decrease in size of COLUMBIFORMES nodes apparent:

of PROCELLARIIFORMES, PHAETHONTIDAE 21. Pigment located in spots just proximal globular

8. Barbule >1.5 and nodes <18 mm nodes and barbules and slender: length mm per very long

PTEROCLIDIFORMES CuCULIFORMES

— Barbule <1.5 and nodes >15 — located in nodes 22 length mm per mm: Pigment

LARIDAE, STERNIDAE 22. In the basalmost barbules nodes abruptly decrease in

9. Barbule 3 size short distance 23 length > mm, prongs usually asymmetrical over

ACCIPITRIFORMES — No reduction in size of basalmost nodes 24

— Barbule length <3 mm 10 23. Barbule length >1.7 mm (barbules often in clews),

10. Prongs only at one side of the majority of barbules: most nodes elongate in shape:

PODICIPEDIFORMES STRIGIFORMES

— — reduction in of Prongs at both sides of barbules 11 Barbule length <1.7 mm and size

Barbule >1.7 nodes in of the vanules 11. length mm: more pronounced one two

CLCONIIDAE, ARDEIDAE, GRUIDAE RALLIDAE

— nodes within Barbule length <1.7 mm 24. Both pigmented and unpigmented occur

GAVIIFORMES, PELECANIDAE, FRECATIDAE, one feather or even in one barbule 25

T — Barbules uniform in 26 PHALACROCORACIDAE, HRESKIORNITHIDAE, pigmentation

Barbules slender and internodes PHOENICOPTERIFORMES, HAEMATOPODIDAE, 25. wavy, kinky:

RECURVIROSTRIDAE, STERCORARIIDAE, ALCIDAE PsiTTACIFORMES

At low barbules sub- — Barbules slender and short internodes 12. magnification (50 x) clearly not wavy, not divided by enlarged nodes and internodes 17 kinky:

— At low magnification (50 x ) no conspicuous subdivi- CHARADRIIDAE, Numenius, Calidris, Tringa, Limosa,

sion into nodes and internodes 13 Arenaria, Philomachus

13. At low barbules visible 26. Barbules slender and in magnification (50 x) as very wavy (often clews),

strongly pigmented threads 14 nodes small and rounded:

— Barbules filamentous and not strongly pigmented FALCONIFORMES

15 — Barbules straight, nodes not rounded:

14. Barbule length >1.7 mm: CoRACIIFORMES, TuRNICIDAE, GLAREOLIDAE,

CAPRIMULGIFORMES Scolopax, Gallinago, Lymnocryptes, Phalaropus

— Barbule <1.7 length mm:

APODIFORMES

Barbule >1.7 16 CONCLUSIONS 15. length mm

— Barbule length <1.7 mm:

RECURVIROSTRIDAE HAEMATOPODIDAE, Using the structure of the downy barbules of

16. At higher magnification x at the basal of (150 ), part feathers establish the one can usually order to the barbules some enlarged nodes are visible which which bird The described char- a given belongs. decrease in size over a short distance:

acters to be uniform within ACCIPITRIFORMES, OTIDIDAE proved very

— x subdivision of but show dif- At higher magnification (150 ) a the monophyletic taxa, striking

barbules is visible, but proximally the nodes are not ferences between birds that occupy comparable

more enlarged than elsewhere: habitats (e.g. Gaviiformes, Podicipediformes, ClCONIIFORMES Anseriformes, Rallidae, and Alcidae), leading 17. Villi present at the basal cells 18

to the conclusion that these characters are not — Villi absent at the basal cells 19

18. Villi recurved and sharply pointed: highly adaptive.

PLCIFORMES several the In groups distribution of nodal

— Villi blunt, knobbed, or finger-like: structures along the barbules is related to the PASSERIFORMES size of the bird. Within the Falconidae, 19. nodes Multiple present:

GALLIFORMES Galliformes, Rallidae, Laridae, Sternidae,

— Multiple nodes absent 20 Psittaciformes, Strigiformes, Coraciiformes,

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has the bird be obtained Piciformes, and Passeriformes, a tendency can without exactly know- been found birds fewer nodes the actual involved. This is that larger possess ing species impor-

barbule than smaller birds. tant is factor in the of per mm as weight a key analysis

bird strikes (Buurma, 1984). For example,

within the Passeriformes be crows can always

from small In DISCUSSION distinguished songbirds. a similar

a distinction be made between way, can ducks,

identification of feathers is based Anatidae. Microscopic geese, and swans in the family

observation that the fine of In of on the structures contrast to mammals, the phylogeny feathers from each of bird differ birds is still understood species just as very imperfectly (see

characters. The the discussion between do other more closely two e.g. Cracraft, 1981, and

the alike the feather the constraints species are related, more Olson, 1982). Owing to of

and It that the the of birds is less structures are, conversely. seems flight, general morphology complexity of feather structures generally diverse than that of mammals (discussed by follows the taxonomic order, although the exact Wyles et al., 1983). The application of the value of this set of characters for avian tax- method of phylogenetic analysis is hindered by

remains be evaluated. It is evident the in character onomy to difficulty recognizing clearly that of the described characters unite that either some states are plesiomorphic or apo- several orders, whereas other characters morphic.

families separate that are usually grouped Recently the amino-acid sequence of the eye within that one (assumed) order. Groups attract lens protein a-crystallin A was studied in 19

and bird 14 orders special attention are the Falconidae the species, belonging to (Stapel et

Rallidae. Their downy barbules have al., 1984). This study provided new evidence microstructures that are totally different from that the Ratites are the sister-group of all other their alledged relatives, the Accipitriformes and birds. However, the resolution of the method is the remaining Gruiformes, respectively. insufficient to determine the relationships of

The identification method described in this most other orders. paper has been extensively applied to the study Comparative studies on feather keratins car- of collisions between birds and aircraft (bird ried out on solubilized S-carboxymethyl (SCM)

In combination with the method of show that the strikes). proteins patterns on

with bird it comparing feathers skins, usually polyacrylamide gel electrophoresis (PAGE) are leads identification and that contain taxonomic to at order-, family-, or complex they may

The level is fur- of for species-level. of identification information. Comparison these patterns ther influenced the or absence of 45 to the Anseriformes led to by presence genera belonging

the the of additional information, such as time of production of a dendrogram intraordinal

time of the and location. Some feather season, day, height, relationships (Brush, 1976a, b).

bird this is keratin Applied to strike analysis, method a monomers are species specific, whereas

of methods of others tissue and be major improvement existing are specific appear to

identification. In = 97% of all cases (N 658) the characteristic of various feather parts such as order could be established (in the remaining the vane or rachis, or are typically found in the

3 bird strike could be but of the feather % a usually confirmed, pennaceous or downy portion the material was not sufficient for further iden- (O'Donnell, 1973; O'Donnell & Inglis, 1974;

in 47 tification), % of the cases the species could Fraser & MacRae, 1976; Busch & Brush, 1979). be established (Brom, 1984). For bird strike Studies on the internal structure of shafts and

it is useful analysis very that in several groups barbs (by means of transverse sectioning) sug- of birds medulla a tendency exists that larger birds have gest that the cellular arrangements in fewer nodes constitute per mm of barbule than smaller and cortex a taxonomically impor- birds. In this indication way an of the weight of tant character: these configurations are con-

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stant within a differ 1959. The structure of feathers in and its species, from related , Meropidae evolutionary significance. Int. Congr. Zool., 15: species only in detail, and include a basic pat- 452-455. tern common to all species of a family (Frank, 1964. The of dif- , possible evolutionary significance 1939; Auber & Appleyard, 1955; Auber & ferences in feather structure between closely related

Mason, 1955; Auber, 1957, 1959, 1964; Pittidae (Passeres: Mesomyodes). J. Linn. Soc.,

45 Swales, 1970; Dyck, 1977). (Zool.), (305): 245-250.

AUBER, L. & H. M. APPLEYARD, 1955. The structure of A more detailed study of the ptilomorphology the feathers in Chlorophanes and Iridophanes (both external and internal) might answer the (Coerebidae). Ibis, 97: 252-258. questions (a) to what extent are feather charac- AUBER, L. & M. V. MASON, 1955. Structurally coloured and ters which characters are to be feathers. adaptive, (b) pattern marks on the inner webs of flight

and 97: 259-265. considered primitive which are derived. Ibis,

BENNIKE, O. & J. DYCK, 1986. A subfossil Lapland Bun- These aspects of phylogenetic analysis will ting Calcarius lapponicus feather from Volvedal, detailed which require a comparative study North Greenland. Ornis scand., 17: 75-77. lead datawith the rela- may to new a bearing on BROM, T. G., 1980. Microscopic identification of feather- of birds. The fact tionships of the higher taxa remains after collisions between birds and aircraft: 1-

that the 89 general structure of barbules often does (mimeographed report, Amsterdam).

within entire orders families makes , 1984. Microscopic identification of feathers in order not vary or to improve birdstrike statistics. In: M.J. HARRISON, these characters suitable for phylogenetic S. A. GAUTHREAUX & L. A. ABRON-ROBINSON eds., studies at higher levels. The value of this study Proceedings Wildlife Hazards to Aircraft Conference will reside in the it possibility to apply as an and Training Workshop, Charleston, S.C.: 107-119

independent test to the results of several recent (National Technical Information Service, Springfield, Virginia). studies that are mainly based on a molecular , 1986. Identification of bird remains for bird strike approach (e.g. Lewin, 1985; Sibley & Ahlquist, literature 18th analysis: a synopsis. Meeting Bird 1986; Stapel, 1986). Strike Committee Europe, Copenhagen, Working

Paper, 23: 1-7.

BROM, T. G. & L. S. BUURMA, 1979. The quality of iden- ACKNOWLEDGEMENTS

tification: a microscopic key to the determination of

14th Bird The financial support by the Royal Netherlands Air Force feather-remains. Meeting Strike Commit- is gratefully acknowledged. I wish to thank Dr. Jan Wattel tee Europe, The Hague, Working Paper, 19: [1-6],

1981. (Curator of the Bird Department of the Zoologisch & , Microscopische herkenning van veer-

Museum Amsterdam) for the opportunity to study resten: hulpmiddel bij de analyse van aanvaringen material under his care and for his valuable suggestions, tussen vliegtuigen en vogels. Het Vogeljaar, 29 (1): and Anthony James for editorial assistance. Mr. J. 9-17.

Zaagman kindly helped with the preparation of the BROUGH, T., 1983. Average weights ofbirds: 1-131 (Avia- illustrations. tion Bird Unit, Worplesdon Laboratory, Guildford).

BRUSH, A. H., 1976a. Some taxonomic and evolutionary

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