In all the works on animal coloration that have come under my observation, there is a marked absence of any attempt to account for the concealed crests of bright colors on the crown of many birds, notably the Tyrannidae or  Fly-Catchers

Nutting, C. C.

English

University of Northern Iowa

Proceedings of the Iowa Academy of Science Volume 1 Part 3, 1892; (1887) - Article 18 1892 Significance of the Concealed Crests of Fly Catchers C. C. Nutting Copyright ©1892 Iowa Academy of Science, Inc. Follow this and additional works at: https://scholarworks.uni.edu/pias Recommended Citation Nutting, C. C. (1892) "Significance of the Concealed Crests of Fly Catchers," Proceedings of the Iowa Academy of Science, 1(Pt. 3), 42-46. Available at: https://scholarworks.uni.edu/pias/vol1/iss3/18 This Research is brought to you for free and open access by the Iowa Academy of Science at UNI ScholarWorks. It has been accepted for inclusion in Proceedings of the Iowa Academy of Science by an authorized editor of UNI ScholarWorks. For more information, please contact scholarworks@uni.edu. 42 IOWA ACADEMY OF SCIENCES. movement of the northern and western species toward the south and east. Almost without exception the novelties included in the above list come from the north and west. Among mammals the same is true, although the eYidence is not so exten-sive. The Prairie Hare is the most marked case in point. JU<;l'TII,ES. The following species are not found in Prof. Osborn's catalogue. Speci-mens of each are in the University museum. rJPHIDIA. Eutninia saurita (L.). ,Johnson county, Iowa. Uoluber guttati<s, L. Rippey, Iowa. B. F. Osborn. Diadophis punclrltus (L.}. Rippey. Iowa. B. F. Osborn. Crotalus horridus, L. Iowa City, Iowa. J,ACElnILIA. Eumeces septentrionalis (Baird). BATRACIIIA. Amblystoma jrffersonianum (Green), Baird. Specimens from Iowa in University museum. FISHE~. The following species should be added to the list on the basis of specimens from Iowa in the University museum. Ammoccctes niger (Raf.). Jordan. Iowa City. [Moxostoma microlcpirlota1 (LeS.), Jordan. Iowa City.] Uliola forbesii, Jordan. 2 Iowa City. Acantharchus pomotis (Baird), Gill. Iowa City. SIGNIFICANCE OF THE CONCEALED CRESTS OF FLY-CATCHERS. BY C. C. Nl"fTlNG. In all the works on animal coloration that lrnve come under my observation, there is a marked absence of any atte>mpt to account for the concealed crests of brig-ht colors on the crown of many bi rel,, notably the Tyrn1t11 idce or "Fly-Catchers." The writer, although the first, so far as he knows, to offer an explanation for this class of facts, was for a long time compelled by press of other duties, to defer for a number of years any considerable investigation in this direction. Last sum-mer, however, he took the time to exa•mine the collection of T11rn1111idw at the Smithsonian Institution, probably the largest sl•ri('s of this exclusively new world group in the world." lThis is doubtless the same species that Is entered by Meek in Osborn's list as 11!. duquesni'i, and is therefore not a species new to the State. 2Synopsis of Fishes of North America. .Jordan and Gilbert, 1882, p. 174. 3 The writ.er wishes to take this opportunity to acknowledge the never failing court-esy and patience of Mr, Robert Ridgway in facilitating the examination of the splen did collection under bis charge. 1Nutting: Significance of the Concealed Crests of Fly CatchersPublished by UNI ScholarWorks, 1893IOWA ACADEMY OF SCIENCES. 43 The facts ascertained by this examination were briefly as follows: Out of sixty-one gener,1 examined, seventeen contained species characterized by tlw possession of conccalrd crests, and forty-nine contained species without them. That is about twent.y-six per cent of the genera contained species with these crests and seventy-fotu contained species without them. lt has been hcl<l that these crests afforded a good gr,neric character among the TiJl'an11irlw, but the facts just given would militate against this view, a generic character which fails six out of seventeen times being of very q llestionable value. To one acquamted with the North American Tyra1111idre only, there would seem to be a relation between large sized birds ancl tlrn p0sscssion of these crr'sts. T11-n1mws, Pitongus, J[i/011/irn fLnd Jf.11iod.1J11"stis are the largest of our Fly-C<Ltchers, and they all possess conct•aled crests, whilr~ the remaining N. A. genera (seven) all comprise smaller hinls nrme of which exhibit tlw crests. An examination of all the genera of the family, however, shows that this <lis-tinction breaks down almost completely, the average length of those species with the crests bPing 6.5:3 in., and that of those without the crests being G.47 in., an en-tirely insignificant diffarence which would be much reduced if the long-tailed species of Milon I us wr•rc taken out of the first class. Thrre is, as would lw expected, a marked relation between the general color of the birds and that of the crests. Thus out of seventeen genera with crests, thirteen had red or yellow crests as-sociated with an ab,;>mce of yellow in general color. Only two had red or yellow crests associated with white in general coloration, and one of these, Milon/us, showed retl on the axillars. Thus we see that in sixteen out of seventeen casetl, or 94 per cent, there is a marln~d relation between the color of the c:mcealed crests and the general colora-tion of the birds. A condensed statement of the facts may be as follows: First-About 2,5 per cent of the genera :if '/'.'frll1111idcc contain species possessing concealed crests. Second-This crest has no reliable value as a generic character, holding good in only two-thirds of the genera. Third-There is no relation between the size of the birds and the possession of concealed crests if we take the whole family into account, although in North America the largest species have crests, while the smaller have none. Fourth-There is an obvious relation between the color of the crr;sts and the general coloration of the bml, a large proportion of species with red and yellow crests, having yellocv as a main feature of their general coloration. Let us now attempt to explain the significance of concealed crnsts in the life of the birds. Their frequent occurrence would indicate a priori that they are of ser-vice to their posse,;sors, and to point out that service is the main object of this paper. In Vol V, page :mr; of the proceedings of the U. S. National Museum is the first suggestion of the significance of these cone-ea led crests that I have been able to find. lt occurs in a report written by myself on a collection of birds from Nicaragua. Jn discussing ,lfuscivora mexicana, '1 species of Fly-Catcher with a marvelom1 fan-shaped, erectile crest, the fol lowing hmguage is used: "Is it not possible that this bird is provided with its remarkable crest for the purpose of attracting its insect prey, and that the slow and regular waving motion 2Proceedings of the Iowa Academy of Science, Vol. 1 [1893], No. 3, Art. 18https://scholarworks.uni.edu/pias/vol1/iss3/1844 IOWA ACADEMY OF SCIENCES. is calculated to still further deceive by a simulation of a flower nodding in the breeze?" l may add that further observations on the rnme species convinced me that my explanation was correct. Mr. Charles W. Beckham, in a paper published a year or two later (which I am unfortunately unable to find), has the following to say in relation to the common "Kingbird" or" Bee Martin:" "Several years ago I saw one of these birds occupying an expoeed perch on a pear tree in bloom about which many bees were darting. Several times I observed that the bird caught the insect without leaving his perch, by quickly turning his head and grabbing them. My attention being thoroughly aroused, I noticed that rnany of them seemed to fly directly toward him, the majority seeming to 'shy off' at a sh Jrt distance and change their course, but very few that came within reach escaped him. Tht> question naturally suggests itself: Did the thrifty hymenoptera mistake the fully displayed orange-red crown (I could see that the crest was erected) for a flower? " 1 Mr. Beckham also quotes my own obsetvations on Muscii·ora mexicania above referred to. From that time to this there has been little attention paid to the matter, as far as I can ascertain. The later writers such as Wallace and Poulton have ignored the question entirely, although they recognize similar phenomena in regard to animals, and have grouped them together for purposes of discussion. Wall ace says :2 "Besides these insects which obtain protection through their resemblance to the natural objects among which they live, there are some whose disguise is not used for concealment, but is a direct means of securing their prey by attracting them within the enemy's reach." ''Only a few cases of this kind of coloration have yet been observed, chiefly among spiders and mantidm; but no doubt if attention were given to the subject in tropical countries many more would be discovered." Poulton in his "Colors of Animals," says: "Special aggressive re3emblance sometimes does more than hide an animal from its prt>y; it may even attract the latter by simulating the appearance of some object which is of especial interest or value to it." 3 Mr. Poulton cites the case of the Asiatic lizard which is colored like the sand on which it Jives. A fold of skin at the corner of the mouth is red in color and is "produced into a flower-like shape exactly resembling a little red flower which grows in the sand." This the lizard successfully uses as a decoy for catching its insect food. Beddard is the only recent writer, so far as I have been able to discover, that alludes in any way to alluring colors among birds. After speaking of the alluring coloration of the lizard" fishing fr0g," etc., mentioned by Poulton, he adds: "It is said that the Lrightly colored crests of many birds act in the same way as a lure. Here of course there can be no question of any special resemblance to a flower." 4 And with this casual allusion Mr. Beddard leaves the question without discus-sion. 1 Quoted by me from Standard Natural History, Vol. IV, p. 499. 2"Darwinism," p. 210. ""Colors of Animals," p. 72. ~"Animal Coloration," p.188. 3Nutting: Significance of the Concealed Crests of Fly CatchersPublished by UNI ScholarWorks, 1893IOWA ACADEMY OF SCIENC.l<.:S. 45 It seems strange that such a strikiP.g assemblage of facts as is exhibited by these concealed crests should have been left so long practically unnoticed by thosA who make a special study of coloration. A partial explanation may be found in the fact that no American has undertaken a serious study of coloration. Tlie Tyrn1111ida' are all A mencan, and British writers have had lilt.le opportunity to study their habits. Another impOt'tant consideration is that the writers on colora-hou have concentrated th('ir attention almost exclusiwly on insects, and have passed over the birdo with an entirely im1rlequate examination of these strikingly colored animals. Let us now turn to the argument, which is based partly on elimination, partly on the study of the habits of insectivorous birds in general, and partly on direct observation. Accordiug to modern ideas all special organs or characters are supposed to be of special nse in the economy of their poscssors.1 Colors are usefol to birds in mar.y ways. These uses have been divided into four general chlsses, protectire, 11,rrqressire, dii'I cl ire and atlraclil'e. Protective coloration includes all cases where animals are helped in escaping their enemies by their cdorn, either by a resemolance to environment, which aids in concealmrnt, or by a mimicking of dangerous or distasteful forms. This in-clndes both true mimicry and warning coloration such as is exhibited by skunks, coral snakes, wasps, etc. It needs no argument to show that concealed crests do not come under this head. Directive coloration furnishes a means by which individnals, particularly of grrgarious specieP, may keep track of their fellows after being scattered. The crests of Fly· Catchers are probably concealed during flight and at any rate 1.,annot be seen at a suflicient distance to be effective as directive colors. Atlractire coloration includes all C<tses when the colors servP to attrnct the at-tention and secure the favor of the mate. They are generally, among birds at least, secomlary cexual characters and one usually considt>red to be a product of sexual selection. They are apt to appear in the male only, or to be especially mtense in that srx. One of the most notable peculiarities of the concealed crests of the Fly-Cc1lchers is the fact that they are h11:.uioblfJ possessed by both se.ces. Among the sixty-one genera examined by me, there was not one in which the male alone h<td a true concealed crest, although in a few rare instances it was much more conspicnous in the male, nnd in one, .Muscil'orn 111e.ric111w, the crests wPre equally conspicuous in both sexes, but crimson in the male and bright yellow in the female. These crests, then, can lrnrdly be regarded a-; secondary sexual characters, and hence, cannot be considered as coming undrr the head of attractive coloration in the technical sense of the word. There remains bnt one more class of coloration, and that is aggressive colora-tion, which assist' its po,se<sors to c~tptum their prey. It is the direct opposite to protective coloration; may be such as to aid an animal in ~talking its quarry, or it may serve r1s a decoy to attract the prey within reach of the animal pnrsuing. It is evident that the bright crown pakb of the king-bird C<tn be of no service in con-cealing the bird from its insect food. Hence, uy a proces~ of exclusion we come to regard the concealed crests of Fy·Catcher;i as 111/urinr1 coloration. Of course, this reasoning is or little weight if taken alone. A much more im-IRudimentary organs or eharacters would at first sight seem to be an exception to this i·ule; but ru<lirnent:try organs are, in nearly H.11 cases at least, regarded as rem-nants of organs once functionid and useful to their possessors. 4Proceedings of the Iowa Academy of Science, Vol. 1 [1893], No. 3, Art. 18https://scholarworks.uni.edu/pias/vol1/iss3/1846 IOWA ACADEMY OF SCIENCES. portant step in the argument is taken when we discover that the true concealed crest.~ are a/1raysfound amo11r1 inseclirorous birds. and nowhere else, so far as I can dis-cover, among American birJs, at least. 1 They occur among the '1'11rn1111idw 0.cy· 1·hatnphirlm, Pipridm, Tanag1'idw and the Re,q11li11!f;. Now, all of tlwse birds are essentially i1rnectiroro11s and I have been unable to find Now, when we adJ to these com;iJerntions and facts the observations of l\Ir. Beckham on the Kingbml, and myself on Musciro1·n me::cicana, in which cases the crests were seen to be of direct service in alluring insects; the theory m~ty be regarJed :ts practically demoustr,Lted, although a larger number of observ:ttions is greatly to be desired. Another interesting fact is that :tll of these crests are ei"ectile, and are conspic-uous when erected, and partially or eomplcb"ly concealed when not erected. In-Hectivorous birds which are without these crests often erect the feathers of the crown when excited by anger or the proximity of food. I noticed Inst summer, while visiting Mr. Uidgway, that his pet song-thru,;h always erected its crown feathers when about to peck a fly from anyone's fingers, which was its habitual way of feeding. Many Tyra1midac have yellow or red as pm·t of their general coloration. 8ome of these colors at the b:tses of the crown feathers would be exposed when the feathErs are erected in the excitement incidPnt on the approach of' insect prey. If this tended to benefit the l.mtl by attracting the insects, natural selection would preserve and intensify it, and we may thus see the means or method by which concealed crests may have originated. It may be ouggested in conclusion that theoe concealed crests are probably among Nature's latest devices wherewith she has equipped her feathered favoriteR. The fact th:tt they appear among the most highly specialized genera of the T,1,nw· nidie, and are often sp2ciflc and not gen~ric characters, show,; th•!lll to be lately ac-quired. Another indication of the same truth lies in thP, fact that, in many spe-cies, at least, the crests are acquired rather late in life, young birds having- little or no trace of it. PI-L'ENOLOGICAL NOTES FOR 1892. BY L. H. l'A)DIEL. It has always seemed to me that there is abundant room for such botanists as have little time to do original work to devote a few moments in taking notes on the leafing, flowering and ripening of seeds of our native and cultivated plants, in short eyerything that may be eonsidered under the head of pbmnological observations. These observations, like those on the pollination of flowers may be made at odd moments and would be of great service to working botanists. If a few scattering botanists would only col-lect insects on various flowers and make lielcl obsen·ations, then turn them over to a botaniEt like Mr. Roberts, it would be of incalculable benefit. So, too, in this phmuological work botanists all over the country should make a few observations, bring them together so that some general conclusions !There may be other cases amon~ Central and South American birds, a• lack of time prevented my i::oing through t,he whole series rts carefully as I could have desired. a single well-defined concealed creot which is possessed by anon-insectivorous bird. 5Nutting: Significance of the Concealed Crests of Fly CatchersPublished by UNI ScholarWorks, 1893

Significance of the Concealed Crests of Fly Catchers

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Significance of the Concealed Crests of Fly Catchers

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