Posted on Authorea 4 Mar 2021 | The copyright holder is the author/funder. All rights reserved. No reuse without permission. | https://doi.org/10.22541/au.161487405.53428023/v1 | This a preprint and has not been peer reviewed. Data may be preliminary. hs nig upr h ointa vltoayaattoso ete risaesgicn cosbird across significant are traits feather of adaptations evolutionary that notion the respect support with was findings associated significance These are niches. the birds, microstructure feeding for water feather aquatic the in observed For in differences was that differences structure. showing difference to feather niches such in aquatic similarity No all among indicating found niches groups. foraging these significant bird proved between land niches group foraging two distinction in approach. bird ANOVA significant evolutionary land differences the and no an water explain of of demonstrating reliability were birds medians parameter statistical land There deflection the the and between confirming ANOVADifferences water birds relationships. phylogenetic land for A phylogenetic or niches niche. for water foraging two for foraging accounting the aggregations each into while for if grouped before microstructure deflection determine species niches vane feather to the bird alighting. and foraging of followed land calculation stiffness and nine the Twelve was barb allowed diving into measurements approach for These of barbs. grouped medians comparison. forces their were and for impact study of families ranges this the spacing in bird included to water and were niches resistance 37 diameter, foraging details provide representing length, these study, also species of this they measurement 49 In if end, penetration. see water this to to To resistance examined and further repellency water were confer optimally that third T Abstract: therefore across are significant feathers patterns. are of behavioral variations traits and in morphological feather and habitats differences of mechanical different to observed was adaptations to The respect significance evolutionary adaptations with niches. birds, that considered foraging associated water notion respective are their the the was microstructure and For support difference species feather findings bird structure. in such These feather differences No niches. in that bird feeding similarity showing land groups. aquatic indicating niches and niches aquatic these water all foraging between of among bird distinction while medians found land the evolutionary microstructure parameter two confirming an feather the deflection birds approach for the in demonstrating land ANOVA observed between differences or significant phylogenetic water Differences explain proved A for birds niches approach. aggregations ANOVA niche. calculation land foraging group the foraging and the significant of water each no allowed reliability were for for measurements There statistical niches deflection These relationships. foraging vane phylogenetic the and comparison. for if stiffness for accounting species determine barb study bird to were for land this Twelve followed families medians in barbs. bird was and water their included of 37 ranges were representing spacing the niches and species of diameter, also 49 foraging they length, end, two if of this see into measurement To to before alighting. grouped examined optimally niches and further that foraging were diving one-third nine details of distal into these forces their study, grouped impact this in In the details to structural penetration. show resistance water provide to to well-known resistance are and birds repellency water water confer of feathers contour The Abstract: Abstract 2021 4, March 2 1 Rijke alighting Arie and the plunging to diving, adaptations of exhibit forces birds impact water of feathers contour The ot-etUniversity North-West Virginia of University 1 ila Jesser William , ecnorfahr fwtrbrsaewl-nw oso tutrldtisi hi itlone- distal their in details structural show to well-known are birds water of feathers contour he 1 utvBarnard Gustav , 1 2 olfCoertze Roelof , 2 n ekBouwman Henk and , 2 Posted on Authorea 4 Mar 2021 | The copyright holder is the author/funder. All rights reserved. No reuse without permission. | https://doi.org/10.22541/au.161487405.53428023/v1 | This a preprint and has not been peer reviewed. Data may be preliminary. fpyoeyi o odtoe nteaayi.Orhptei sta h otu eteso ae birds water mechanical of patterns. and feathers behavioral morphological contour and habitats penetration, the aqueous water that to specific is for resistance hypothesis estimates advantageous and Our are parameter repellency type that incorrect water analysis. high features infers to to the and simulation addition due in Adams based this inaccuracy in conditioned 2003; is Therefore, statistical exhibit, not phylogeny to simulation. al. is across prone phylogenetic et phylogeny are of trends (Blomberg if variations use evolutionary models its phylogeny and linear establishing and the errors for analysis of consider I coefficients this standard to However, of important The patterns 2018). these estimation is trait Collyer squares to groups. the it least adaptations where compared, the generalized studies are as in on and In niches identifiable species plunging, niches. foraging are the diving, foraging as of that of determined, such impact inito properties groups the ab biological structural different, specifically between the of habits forces, comparisons feeding mechanical and by the of feathers forces with 1989). effects vary contour the al. not on diameter et consider does the alighting, (Rijke we and barbs by 4.5 paper, for for about only parameter this does at wettability determined barbules. In the families it adjoining is that bird as is the all families feather Noteworthy for bird of the constant barbules. water flanges through less the of the or water to in more recourse force They without is sliding to barbs barbules hooks barbs. the required their between of the pressure spacing with penetrates on the and separation water based result, own when not a the their instance, preventing is As increasing for by penetration mechanism by forces, way interlocking water so mechanical an other to provide do under the barbules resistance separating Instead, is and from it barbs. barbs repellency to birds, applies water land as to mechanism of repellency, same barbules water feathers of poor contour contribution have the The penguins For of feathers penetration. contour the water that to around. implying resistance to birds, proportional excellent land inversely typical but is for barbules, more and barbs or the to 7 as through well water as force parameter to this required pressure the as expressed parameter wettability the of value the the by to rated be penetration can water feather contour to the This of resistance part ( water. and this of or repellency repellency air water water critical The to confers so exposed also arranged rigidity aspect are It the dorsal They plumage. with their properties. body distal. one-third having mechanical more distal roof, next its the patterned, a barb for provides a on the ones arrangement have shingles of distal one-thirds hook-and-flange barbules like the continuous-looking, distal which proximal fashion of curled, The overlapping 1961; barbules the Farner an sprouting 2002). upon and each in catch (King rachis, al. that the air et rachis from entrapping hooks by extending have Lei the barbs temperature of 2000; with body two-third Stettenheim structure regulate proximal pennaceous 1972; to the Stettenheim means their alongside (Thomson a and literature of parts as Lucas ornithological (plumulaceous) function benefit the to downy optimal in thought The described the are well to 1972). been have qualities Stettenheim feathers such these 1964; contour to confer of details signaling that structural elements intraspecific The of from array therefore, range surprise, an no that is of bearer. It functions avian composed impact. of are to variety resistance they and a repellency, that water serve insulation, thermal birds as qualities of physical feathers contour The Introduction patterns. behavioral and feath- of habitats variations different morphological Keywords to and adaptations mechanical considered observed The therefore are niches. ers foraging respective their and species 95 olit16;Rje17) ae eelny xrse ntrso h otc nl ihwiha which with angle contact ( the to of proportional terms is surface, in feather expressed a repellency, on Water rests water 1970). of Rijke drop 1963; Moilliet 1945; 2 and r + d d )/ h eaaino h ab esrdi h ln fteln xso h ab Csi n Baxter and (Cassie barbs the of axes long the of plane the in measured barbs the of separation the r, hr 2 where ae id,cnorfahr,wtrpntain matfre,dvn,frgn niches. foraging diving, forces, impact penetration, water feathers, contour birds, water r eoe h imtro h prxmtl iclro litclcosscino h barb the of cross-section elliptical or circular approximately the of diameter the denotes r ausfrteprmtrrnefo bu . o egis( penguins for 2.5 about from range parameter the for Values . 2 r + d )/ r u eitnet ae penetration, water to resistance but , Spheniscidae to ) Posted on Authorea 4 Mar 2021 — The copyright holder is the author/funder. All rights reserved. No reuse without permission. — https://doi.org/10.22541/au.161487405.53428023/v1 — This a preprint and has not been peer reviewed. Data may be preliminary. oc sapidt h ae h eua ipaeeto h iso h aeprrpaigui 2( unit the repeating When per vane shaped. the cylindrically of be tips to the assumed of here S displacement are flexural barbs as the modeling, written vane, be of the can purpose to applied the For is force 2014). al. et where distance a S over flexing be engineering tip can its hypothesis in with our described to force well relation in force been a conclusions have When of sizes meaningfully number and a be that shapes not considerations different However, would these water. of drawn. from data with is materials interaction such it forceful of and during Any vanes measurement flexing physics and direct way. and barbs to of representative bending flexure accessible or or the not yield reliable resulting are the any alighting to in correlated and a plunging, technologies in diving, current feathers in by nine involved lower of forces the average mechanical in an The families show for birds stack Land a measurements in birds. Feather heavier feathers 15 for number to 10 that stack. twice results about area with yields the surface range calculations, Combining 200,000/m per weight to these weight feathers weight. to m body of relationship according with per body and number the increases overlap, 150,000 of (2014) in number For to This expressed Pritsos function 100,000 densities studied. and obtained. a approximately feather species Moye was be as contour Perez, to bird area calculations, found by the of surface were al. proposed of sets of estimate two estimate et expressions mass fitting to these an Hoyo mass, By the used of penguins), (Del body of were purpose. and HBW and function our (1936) birds source for area a small Mitchell our averaged very surface as as being by on feathers body birds used those reported contour between female we (ignoring Lowe as of and birds data weights 1932; number male these the body both Knappen the to of for and 1903; polynomial weights ranges feathers McGregor second-order the weight of a 1900; For the number Dwight 2013), 1957). on – 1933; Hesse data 1997 Ball and the and Kuhn of Hutt 1933; use 1936; (Wetmore made of we authors extent several latter, the the and estimate density To of feather feather product rachis body three the the of least area. by of At calculation surface approximated length the microscope. be the For traveling can measured a overlapping we using examined. overlap, millimeter were feather half species contour nearest each the to of vane techniques. of specimens the imaging precision of and electronic data length accuracy mid-part with The the barb the collected suspect those ocular. for to of scale values reason than calibrated The no less a see anything We with be equipped 1. to Table of microscope data in light list convenience these transmission for A a reproduced 2013). by been using birds not. – have suggested study have 1997 water sequence 1970 that al. Here, taxonomic the et those and of Hoyo as 1970). names (Del for Our English birds (Rijke (HBW) values using World land birds The 1, the water. and water Table of water in with of Birds compiled open the interface study is of with earlier to study Handbook habitats this an likely have in in most that species used the birds the as as as same defined selected the are were was feathers source abdominal primary feathers, contour For material Feather Methods and Materials v = = l . F F E v . tnsfrteYugseatcmdlso h ete eai Bne n uso 95 Greenwold 1995, Purslow and (Bonser keratin feather the of modulus elastic Young’s the for stands l 3 3 /2 2( . . π F r r r sapidoe h egho igebr,tebr ilbn ntedrcino h applied the of direction the in bend will barb the barb, single a of length the over applied is 4 and + . d E )/2 d (1) fteefahr,maue ttemdpr ftevn,wr olce ttetime the at collected were vane, the of mid-part the at measured feathers, these of . π r l 4 ftecoe encosprino h otu eteswr esrdat measured were feathers contour the of portion pennaceous closed the of . E (2) S hsrltst h ablength barb the to relates This . 3 L f n h qaero ftenme ffahr per feathers of number the of root square the and 2 o ae id egigls hn12k o all for kg 1.2 than less weighing birds water for L f otenaetmliee.Teetn of extent The millimeter. nearest the to 2 taot7k.Teetn ffeather of extent The kg. 7 about at l n abradius barb and r as r + d ) Posted on Authorea 4 Mar 2021 — The copyright holder is the author/funder. All rights reserved. No reuse without permission. — https://doi.org/10.22541/au.161487405.53428023/v1 — This a preprint and has not been peer reviewed. Data may be preliminary. ntedffrn edn ihsaeilsrtdi i.1adFg 2. Fig. and 1 groupings of Fig. representative placement in and as illustrated birds well are as aquatic niches species and feeding bird land different between the both relationships www.birdtree.org phylogenetic in for from the generated obtained depicting were were trees the trees genetic species, using 1000 bird constructed A land were 12 trees 2014). and independent Thomas Two aquatic and 49 relationships. (Jetz phylogenetic ex- of niches for consisting feeding accounting whether trees, while determine phylogenetic microstructure to used feather was ANOVA in phylogenetic differences birds, plain deflection land and of birds aquatic with differences both Test For the U the with Mann-Whitey Test phylogenetic of the H Kruskal-Wallis the using Significance the calculated with using was represented phylogeny. comparison species bird niche in of land the foraging and used influence aquatic which were the between values determine results substantiate parameter to These to calculated results values. were ANOVA parameter groups deflection between 0.824 higher/lower parameters = (W deflection distributed p normally of not of was Significance dataset values 3.6.0). parameter (version deflection the for with software normality recognized analysis of statistical test was Shapiro-Wilk R analyses the all using been conducted not for were have purpose). and analyses archival incomplete statistical for were were exceptional All land here dippers their dippers, Twelve two (reported of into and the calculations account divided (2020). of on the darter were datasets excluded in species the The were al. twelve included excluding Darters Discussion). These et study, (see aerial/sally). Pigot comparisons. microstructure and this similarity to feather feeders of in accordance (ground purpose birds niches in the foraging aquatic for groups) two included of (independent were species niches species 49 foraging bird the nine to 2, Table assigned in seen As other the of magnitude. higher, ANOVA that of or Phylogenetic dwarfs orders 7 and three to parameter about 2.5 by deflection in of so the range parameter does that to long its bending, wettability Note contribution over their whereas the its prevent not. factor: bending, of help enhances do also resisting markedly appearance penetration feathers which stiff The water repellent power vane to water resistant the bending. highly feathers make ratio promotes that whereas the barbs shows that (1) parameter thick flexibility associated as factors: deflection and favor two forces the expressed short of barbs of barbs consists that impact thin the - the indicates and parameter of under factor deflection thickness feather the first the contour as The to the are to of length barbules referred vane size, here the bending. primary the small - of to of alighting their their resistance or for bending of over-all sliding diving mostly the light the with hooks but 2a, to the their reason, contribution Eqn in by any, this to so For considered if According doing minimal, be distal. and a more to force only next is make applied barbule vane to an the the assumed under of of separating flanges from bending the barbs the in resisting the of in keeping spacing barbules i.e., and function, the dimensions of the role from force The 2( variables applied distance feather an the a under over of vane alone. up the measured barbs made of and is bending barbs equation the the the semi-quantitatively of of lengths side right-hand the unlike over the that applied Note force vane. of unit per + barbs of tips the from Apart π subscript the where .E.S d wilcox.test .Frtebnigo h nievane, entire the of bending the For ). v S /F v v and ( = π F n h lsi modulus elastic the and l/r ucin infiac fdffrne ewe oaignce fautcbrswscalculated was birds aquatic of niches foraging between differences of Significance function. v r aiyaddrcl cesbet esrmn.Teecnieain lo st predict to us allow considerations These measurement. to accessible directly and easily are , ) 3 ( . v eest h eetn nto h ae eragmn fEn2te yields then 2 Eqn of Rearrangement vane. the of unit repeating the to refers r + d )/ r (2a) maxCladeCred shapiro.test E kruskal.test h ethn ieo q arpeet h xeto eigof flexing of extent the represents 2a Eqn of side left-hand the , F v r+d)/r + (r ed ob osdrdfrtenme frpaiguisper units repeating of number the for considered be to needs ucinfo the from function < ucinfo h aefntos twssonta the that shown was It functions. base R the from function .5 omlt fdtst a acltduigthe using calculated was datasets of Normality 0.05. 4 function. nrae yol atro r4 hra ( whereas 4, or 3 of factor a only by increases l/r l/r n 2 h etblt parameter wettability the (2) and nesteeuto ntefr fathird a of form the in equation the enters phangorn p , < .0) infiac fdifferences of Significance 0.001). akg vrin253.Phylo- 2.5.3). (version package l , r and r+d)/r + (r d which, , l/r ) 3 r . Posted on Authorea 4 Mar 2021 — The copyright holder is the author/funder. All rights reserved. No reuse without permission. — https://doi.org/10.22541/au.161487405.53428023/v1 — This a preprint and has not been peer reviewed. Data may be preliminary. aiis u,a hw nTbe3 eraigys o h aiisls niaewt pnwtr Swimmers of water. aquatic open with most intimate the less for families true the particularly remains for is that so water This decreasingly with barbs. 3, contact Table the in in through area shown water surface as force their but, the to on families, of required pressure that a exception behavior. exert below possible weights, the well and their the habitat for by their values with birds, of large Swimming species, requirements unusually specific other prey show the all stalking feathers suit However, while to contour buoyancy resistance Their reduce together. Only ( to all streams. Cormorant penetration. order barbules and water Flightless in lack to lakes skin resistance shallow and the the reaching of parameter greater water bottoms the from the are, benefit values on to these known spacing smaller and are The diameter darters ( the 2011). by parameter Jesser skin the the and by to Rijke determined penetrating as water barbs from protected the are of birds, water particular in Birds, ( observed was niches feeding bird Discussion land two results aquatic the between The for microstructure microstructure feather phylogeny. in feather difference ( the significant groups a and is bird niche, there by that foraging affected demonstrated ( results be ANOVA birds e. would aquatic and methodology either of ANOVA 0.650 i. for degree = aggregation the variable, group The if while independent significant establish microstructure no the followed. indicated feather to between was explain order birds approach association in ANOVA land the determined and phylogenetic was aquatic a aggregation for relationships, niches group foraging phylogenetic the for if accounting niches. determine aquatic to in order differences In to respect with identifiable are microstructure qai ufc n qai ec (276.10 Perch Aquatic and (328.10 Surface Dive foraging Aquatic Aquatic between bird (37.10 differences land significant Surface expressed two however, Aquatic the species and bird of aquatic parameters The deflection birds. land the between difference significant ( niches no was There groups. efudasgicn ieec ewe h eeto aaee ein fautc(260.10 and aquatic Feeding of Ground medians parameter niches: deflection darters two study, the into this between grouped of difference categorized (1595.10 be species significant were could bird a niches water species found foraging of We 49 bird major all the land six accommodate for 12 to 2). identified these The (Table us were Of Aerial/Sally by niches excluded. chosen world. Thirty dippers (2020) more the and three al. delimitation. of et with niche Pigot species Aquatic by foraging bird as proposed for 10,000 procedures followed protocol approximately have standardized we the niches, a foraging on to species based bird than the datasets. assigning accurately multivariate In more highly context for phylogenetic appropriate a more in also exist, Results is they RRPP if has using models. it detected, iterations Moreover, simulation ANOVA. be 1000 phylogenetic phylogenetic can in in in differences aggregation performed group group was that for analysis shown accounting This of approach importance (2018). ANOVA the phylogenetic Collyer the demonstrated (RRPP) and as procedure Adams regarded permutation by the were a described in 2 as residuals Table used considered randomizing was in were a parameter listed study, deflection this niches to In foraging regard The with microstructure variables. aggregation. feather dependent group on as no the Data using indicated variable. calculated 0 independent was of trees value phylogenetic the a on groups the bird from the of aggregation Group procD.pgls p 6 idfrgn ihs( niches foraging bird ) .0) rudFeig(1228.10 Feeding Ground 0.600), = geomorph p p .2)wihcnre h ttsia eiblt fteAOAapoc.Tephylogenetic The approach. ANOVA the of reliability statistical the confirmed which 0.120) = ucinfo the from function .0) eadeso hlgntcrltdes ncnrs,n infiatdffrnein difference significant no contrast, In relatedness. phylogenetic of regardless 0.001), = akg vrin312.A -au f1wsidctv fttlgopageainand aggregation group total of indicative was 1 of R-value An 3.1.2). (version package .harrisi P. 6 ( ) p p .1) qai ufc n qai lne(935.10 Plunge Aquatic and Surface Aquatic 0.012), = geomorph < ,hv otu ete tutr htotmzswtrrplec and repellency water optimizes that structure feather contour a have ), .0) hrb eosrtn neouinr itnto ewe these between distinction evolutionary an demonstrating thereby 0.001), akg vrin312.Ti ehdi eeca ic thas it since beneficial is method This 3.1.2). (version package 6 6 n eilSly(2864.10 Aerial/Sally and ) ( ) r + p d .0) hs eut hwta ieecsi feather in differences that show results These 0.001). = )/ 5 r n h bouevleof value absolute the and r .6 and 0.468 = 6 ,wihidctssmlrt among similarity indicates which ), p 0.971). = r p Bxe n ase1945; Cassie and (Baxter .2)o adbrs( birds land or 0.122) = 6 ( ) two.b.pls p < 6 .0) and 0.001), n land and ) function 6 r ) Posted on Authorea 4 Mar 2021 — The copyright holder is the author/funder. All rights reserved. No reuse without permission. — https://doi.org/10.22541/au.161487405.53428023/v1 — This a preprint and has not been peer reviewed. Data may be preliminary. . gd efida nraei ete est n vra ihwih:u o2000prm than per more 250,000 weighing to birds up for weight: mass. Only with to overlap as proportional and same. ( and, directly density the pelican birds are feather also pink-backed water in the is increase all for an for bending approximately 18 find same with to we groups the provides do all is stacking kg in overlapping birds 1.2 restriction feather for Apparently, the stack a birds. result, 100,000 in heavy a approximately feathers more for 15 are the number to overlap there that 10 feathers shown about double the to have the amounts of more overlapping calculations measure m of bending the to our extent per However, difficult and by feathers is coat caused and attained. 150,000 extent feather plunging be to is which the in also to bending denser but may but to the feathers, bending, penetration restriction expect contour impede water would outer should exceeds surfaces, One bird the feathers water experimentally. the contour of of on stacked barbs weight landing Closely the the birds if vanes. through skin or water the birds reach force ultimately diving to may required water that pressure vanes seen the dissimilar have and we feathers flexible birds, contour more swimming their For habits, less in feeding with vanes diverse this species protection. more similar with whereas such from very skin, parallel no apart the and in with have, In reaching stiff water water prey have niches. open against their with foraging species protection interaction increased aquatic other pursue providing most the all bending, the in resist cormorants words, that families and other taxonomically for for In the grebes true values for less others. the divers, so holds that less Penguins, find this but we niche, but observation, niches. way, foraging Dive same other Aquatic the interaction in the and much in habits families feeding families their distant for to evident respect more in is with behavior differences This similar these a water. forces share that with niche the habitats. foraging posit to each and We adaptations in evolutionary habits families feathers magnitude. represent The feeding contour bending of specific these to and orders with resistance birds, three petrels, of associated land range as storm impact of wide much and those those of the as jacanas with than as by Compared well finfoots, so as bending of more waders. magnitude to those of times resistant thirty thicker, those than and than more so species: shorter so are more aquatic much more times are less times fifty that birds. of hundred cormorants, barbs swimming those six have and in than penguins grebes not bending of divers, but and feathers to of - diving contour resistant skin in the more vanes show, the therefore 1 of reaching Table and from flexing It in water and feathers. data unknown. preventing bending stacked the is in the As of all, aid reduce bending at thus to if and and serve penetration, flexing - mostly water on the birds layers to landing alighting by stacked contributes birds skin that mechanisms of however, the dynamic likely, conditions two reach is the these this also resemble of of multiple could closely each Experiments well of much impact this may 1989). How stack on feathers, Mahoney if layer a water through and feather known However, or additional forced Jesser not feather each (Rijke, water. is that contour is water resistance suggest water which single It to but to in a seem increase air, kind, plumage. of are, percent trapped they barbs the 50 as compressed the in another few by through adds data, air water experimental balanced atmospheric available force be The the to not feathers. with enough will gradient large impact pressure is on a gradient pressure thereby produce the depths, hydrostatic instead greater water, by will at on compressed air bird. alighting remaining and trapped the increase, birds the of the trapped longer For buoyancy compresses no but be further the will will expelled, coat interface and water-feather airways, feather volume be the compliant the and will across the decreasing sacs difference immersion, as air pressure air out On some the in balance Initially, deeper, pressures. but as dive temporary, well they water. albeit As as by greater, forces. plumage much surrounded the to quickly within subject be air are will protection hand, bodies further other no their and the provide resistance, bird on will this the birds, and exceeds 1989). of well Diving pressure weight Mahoney as the and the penetrated Once by Jesser be (Rijke, eventually exerted penetration. wetting will pressure resist against feathers the to of between feathers layers equilibrium contour underlying static outer the the less of or capability more the a to subject are 2 o ae id egigls hn12k eadeso ru.Frhroe the Furthermore, group. of regardless kg 1.2 than less weighing birds water for .rufescens P. l / r r ml o pce nteAutcDv ih,btlre nthe in larger but niche, Dive Aquatic the in species for small are .Ti bevto si iewt xetto sipc forces impact as expectation with line in is observation This ). 6 2 n tcsof stacks and Posted on Authorea 4 Mar 2021 — The copyright holder is the author/funder. All rights reserved. No reuse without permission. — https://doi.org/10.22541/au.161487405.53428023/v1 — This a preprint and has not been peer reviewed. Data may be preliminary. e ooJ litA agtlJ(9221)Hnbo ftebrso h ol.Ln dcos Barcelona. Edicions, Lynx world. the of birds the of Handbook (1992-2013) into J birds Sargatal of A, adaptation Elliot the evolution J, Hoyo Dynamic and 14:249 (2014) Del diversification Biol RH integument Sawyer Evol accompanied G, BMC has Zang York – MTP, keratins New Gilbert lifestyles beta Ann C, novel and Li York. alpha H, New Hu the of ED, of birds Jarvis W, passerine Bao the MJ, of Greenwold moults 198:1029-1033 and Biol plumages 13:118-119 Exp of Sci J sequence Acad keratin. The feather (1900) behavioral of J Youngs-modulus Dwight data: The comparative (1995) in PP Purslow signal RHC, phylogenetic Inst Bonser 57:717-745 for Text. Evolution Testing J labile. (2003) test. more AR repellency are Ives water traits T, new Garland a SP, and Blomberg fabrics of repellency water The (1945) 36:T67-T90 ABD Cassie a S, and Baxter challenges, 72(6):1204-1215 biological Evolution aggregation, Group-clade procedure. ANOVA: permutation Phylogenetic (2018) refined separately ML Collyer been DC, not have Adams and Figures and Tables text, the REFERENCES in reported repository. been have a study in this archived in used data text. All the writing RDC to Statement and contributed GRB Accessibility authors Data calculations. five and All measurements interest. analyses. the of phylogenetic performed authors. conflict the HB the no conducted and of WAJ have any AMR, they by contributions: that performed Authors’ declare animals authors with The studies Interest: any of contain Conflict not does article remain This may approval: traits Ethical terrestrial feeding other diverse although more have birds, niches. less and Acknowledgements: terrestrial respective but habitats niche, among birds’ in of Dive the observed have Aquatic range to not but the wider due different, was in a conserved species taxonomically effect which populate the are This which for flexible less groups representatives, true with habits. are these niche particularly birds is of other for barbs This magnitude each for thin of feeding. in so orders of and families by method show increases The long their but to common whereas water. families, able bird open were bending, of with we aquatic resist interaction most general, the and in for penguins, materials stiff for value of small are The properties barbs mechanical bending. the thick facilitates to and referring short adapted By evolutionarily considerably however vary that niche. range feathers eight-fold contour specific an of covering a barbs parameters the to stiffness advantageous of alighting. their diameter are with and supports and birds that plunging length water niches features the among diving, feeding that exhibit the as observed bird have birds such between we water land summary, patterns microstructure In of the behavioral feather feathers and for contour in habitats found the aqueous was difference that specific difference relationships significant study for significant phylogenetic this a such of the is no hypothesis of there That the study, regardless groups. increase this that large bird further in demonstrated water a are have species from species ANOVA benefit bird each phylogenetic not between of do of feathers and and results contour account pattern The own the behavioral their stacking. of of on or number penetration regardless skin density and water the bending feather density reaching to feather in feather water prevent resistance the prevent 1) to and to large possibilities: stiffness enough sufficiently both barb are or the two stack of 2) a any in by feathers explained be of may findings above The l/r n,i atclrtedflcinprmtr( parameter deflection the particular in and, 7 l/r ) 3 ( . d + r )/ r is , Posted on Authorea 4 Mar 2021 — The copyright holder is the author/funder. All rights reserved. No reuse without permission. — https://doi.org/10.22541/au.161487405.53428023/v1 — This a preprint and has not been peer reviewed. Data may be preliminary. DEgihNm eu species Genus Penguin Rockhopper Penquin Gentoo 4 Penquin Magellanic 3 Penquin Jackass 2 Name English 1 area. surface of ID unit per feathers 53:159-169 of Auk number The for birds. stands related N/A and measurements. passeriform in 1 feathers contour Table of number London. The Nelson, 2 (1936) birds. Vol. A of Wetmore dictionary Biology, 40:461-477 Zool new Avian Amer A overview. (eds). (1964) an – JR AL birds Thomson modern King of morphology DS, integumentary Farner The (2000) In: PR Stettenheim birds. 1-63 pp. of York, integument New Press, The Academic 133:245- (1972) Condor water PR The to revisited. Stettenheim feathers resistance of and repellency and repellency penetration water water The 254 (2011) dippers: WA Jesser of AM structure Rijke feather 122:563-568 Ornithol The J (2010) Wilson WA penetration. Jesser AM, ( ( darter Rijke cormorant African the double-crested of the wettability with Plumage compared (1989) SA ) Mahoney WA, Jesser J AM, birds. Rijke water in structure 52:469-479 feather Biol of development Exp form pigeon phylogenetic morphological and homing connects Wettability https://doi.org/10.1038/s41559-019-1070-4 convergence (1970) the Evol Macroevolutionary AM Ecol using Rijke (2020) Nat birds: al. birds. et in of function ET, area ecological Miller surface to C, the Sheard AL, Estimating Pigot (2014) CA Pritsos 2:443-449 JK, Nutr. ( Moye J. – CR, repellency chickens water leghorn Perez and 5:17-20 white Condor proofing comb Water Carpenter The single (1963) skin. JM, of JL bird Miller area Moilliet a FC, surface in Clark The feathers 1930. J, of H. Grinnell number H. E, The Mitchell, Adams (1903) J, ER Warren Mailliard JH, FS, Bowles Daggart N, L, Belding Agr., related RC, Dept. McGregor US and 362. passeriform Handbook in Agricultural Integument. feathers anatomy. Avian DC. contour Washington, (1972) of PR Stettenheim number AM, The Lucas (1936) A 53:159-169 Wetmore Auk in: The birds. Cited gr (1933) verschiedener Taubenrassen PR Lowe bei Pterylose postembryonale 49:461 Die 45:616-655 Auk Tiere (1957) The 215-288 Оkol R duck. pp. Hesse a London, O, on and Kuhn AJ York feathers Marchall New of Press, Number In: Academic (1932) temperature. P birds. body Knappen of and physiology conservation thermoregulation comparative and metabolism, and Distribution Biology Energy (2014) (1961) (ed.) 24:1-12 AO DS Biol 55:651-657 Farner Mooers Curr Auk JR, D, – The King Redding birds birds. K, in passerine Hartmann distinctness in evolutionary JB, size global Joy of body GH, and Thomas feathers W, of Jetz Number (1938) L Ball FB, Hutt ¨ oub livia Columba ito h 4br pce fti td ln ihtercrepnigfahrmicrostructure feather corresponding their with along study this of species bird 64 the of List samdl ilOe 3:486-488 Open Biol model. a as ) uytschrysocome Eudyptes papua Pygoscelis magellanicus Spheniscus demersus Spheniscus hlcooa uratus Phalacrocorax 8 . leir e York New Elsevier, .Otih60:128-132 Ostrich ). 04. .5258. 51.53 3.02 1.19 0.51 25 25 83.3 25 22 107.9 78.1 58.8 2.5 3 2.5 2 2.65 2.40 2.50 49.4 2.51 38.9 47.9 30 51.3 27.8 32 34 r (μμ) d (μμ) nig melanogaster Anhinga ( о s.ZMorphol ¨оsse. Z r + d )/ r l (mm) .

l/r L

f m)N/A(10 (mm) 4 tc eeto aaee (10 Parameter Deflection Stack ) 6 ) Posted on Authorea 4 Mar 2021 — The copyright holder is the author/funder. All rights reserved. No reuse without permission. — https://doi.org/10.22541/au.161487405.53428023/v1 — This a preprint and has not been peer reviewed. Data may be preliminary. 4NmqaSngos (F) Sandgrouse Namaqua (M) Sandgrouse Namaqua 54 Murre Common 54 Skimmer African 53 Tern Sooty 52 Gull Black-backed Lesser 51 Skua Pomarine 50 Sheathbill Pale-faced 49 Phalarope Red 48 Curlew Eurasian 47 Plover White-fronted 46 Dikkop Spotted 45 Avocet Pied 44 Oystercatcher Black African 43 Plover Crab 42 Painted-snipe Greater 41 Jacana African 40 Finfoot African 39 Coot Red-knobbed 38 Limpkin 37 Crane Blue 36 Francolin Coqui 35 Turkey Wild 34 Duck Yellow-billed 33 Goose Egyptian 32 Screamer Horned 31 Flamingo Greater 30 Ibis Sacred 29 Saddlebill 28 Stork Yellow-billed 27 Hamerkop 26 Egret Little 25 Heron Black-headed 24 Heron Grey 23 Frigatebird Great 22 Darter 21 Cormorant Cape 20 Gannet Cape 19 Gannet Northern 18 Pelican Brown 17 Pelican Pink-backed 16 Pelican White Great 15 Diving-Petrel Common 14 Storm-Petrel European 13 Petrel Grey 12 Petrel Blue 11 Petrel Great-winged 10 Albatross Yellow-nosed 9 Grebe Black-necked 8 Grebe Little Diver 7 Northern Great 6 5 trce namaqua Pterocles namaqua Pterocles aalge Uria flavirostris Rynchops fuscata Sterna fuscus Larus pomarinus Stercorarius alba Chionis fulicaria Phalaropus arquata Numenius marginatus Charadrius capensis Burhinus avocetta Recurvirostra moquini Haematopus ardeola Dromas benghalensis Rostratula africanus Actophilornis senegalensis Podica cristata Fulica guarauna Aramus paradisea Anthropoides coqui Francolinus gallopavo Meleagris undulata Anas aegyptiacus Alopochen cornuta Anhima ruber Phoenicopterus aethiopicus Threskiornis senegalensis Ephippiorhynchus ibis Mycteria umbretta Scopus garzetta Egretta melanocephala Ardea cinerea Ardea minor Fregata melanogaster Anhinga capensis Phalacrocorax capensis Sula bassana Sula occidentalis Pelecanus rufescens Pelecanus onocrotalus Pelecanus exsul urinatrix Pelecanoides pelagicus Hydrobates cinerea Procellaria caerulea Halobaena macroptera Pterodroma chlororhynchos Diomedea nigricollis Podiceps ruficollis Tachybaptus immer Gavia 9 66 49 .01 0. 51228.40 126.50 328.11 8.5 541.07 12.5 4884.36 10.6 1019.40 1622.67 968.10 14.7 9.2 64.02 9.7 14.7 9.2 289.41 9.4 25 260.83 25 28 8.6 15.6 600.6 40 11.6 600.6 8.7 300.8 991.08 162.49 35 1214.54 379.1 14.2 13.2 650.98 449.4 10 50 9.7 17.6 127.05 15.3 10 50 8 13.2 8.4 549.0 60.30 55 8 25 9.9 549.0 903.6 6.10 8 47 12.3 8.6 232.6 5.67 991.64 40 462.96 13108.15 8.7 8.6 4.65 14 640.0 84.92 40 6.02 318.5 9.9 2405.66 13.4 14 12.1 77.7 15 5.96 391.32 320.0 9.1 97.2 16.65 45 4 32.6 8.6 106 144.86 33 6.16 60 16.65 16 11.7 555.6 88.3 5.85 26.6 5 42 311.4 550.0 6.62 12.1 1751.00 8.9 131.6 127.37 21.1 9.1 8 33 5.09 463.9 123.8 17.8 16.6 42 6.19 1027.20 16.4 257.5 93.3 12 25.5 8.4 8.96 8.6 11 241.0 2035.44 70.4 9 25.5 18.1 129.8 7.96 45 40 9.1 16.6 1287.81 9 1789.65 14.3 80 563.9 125 5.78 17.2 420.4 10.8 173.9 6 343.48 7.30 11.4 22.5 534.31 40 5.38 25 671.6 27.5 8 13.1 103.3 15.7 40 6.52 429.2 14.5 1102.87 10.1 935.00 126.5 15 589.96 25 1333.3 10.1 126 14 7.44 50 327.9 21.6 18 25.3 25 4.31 23.8 17.9 107 392.06 28.9 733.3 12 50 10 306.1 31.61 150 5.53 20 36 6.23 8.5 45 601.5 8.3 12.5 10 110 19.4 7.94 202.21 120.5 9.3 23.3 709.5 10.1 22 65 10 4.95 98.76 65 174 33.2 9 5.53 12.2 46.45 637.1 16 186 4.11 50 26.6 622.8 35 13.2 9.8 92.1 144.18 33.3 124.5 21 4.44 386.3 14.9 66.13 75 394.1 9.6 312.94 80 26.8 4.44 17.4 95 23 4.72 12.1 23.3 500.0 93.04 103.2 18 560.0 7.9 17.5 12.4 27 5.70 40 132.23 239.23 101 9 13.8 30.5 8 8.4 30 410.4 99 6.92 30 12 5.33 260.58 16.8 24.6 35 14 139 188.0 8.7 29.4 386.1 17.3 56.10 37 213.7 379.1 5.96 10 26.6 13.2 8.73 1403.55 75.93 40 125 42.50 11 311.4 21.8 29.6 7.48 6.28 7.3 115.5 211.6 35 36.1 29.9 10 9.3 5 7.6 157 42 9.1 9.4 28.9 155.5 300.8 8 25 5.67 23.3 8.6 132 386.3 9 18 237.0 10.25 20.3 4 4.76 8.5 12.4 125.1 55 241.0 24 29 3.71 9.2 239.6 8 25 14 332.4 3.27 45 99.9 9 376.6 26.8 5 4.90 57.2 25.9 384.6 25 85 4 65.5 5.30 26.6 25 12 225.1 688.5 73.8 25 5.43 21.1 9 4.97 229.9 114.3 28.9 13 221.5 6.65 103.3 18.9 3.60 83.8 21 26.6 7 4.48 93.8 23.3 6 4.58 7 93.8 21.1 83.2 4.30 16.6 4.92 121 36.1 6.25 100.8 3.91 23.9 122 33.8 137 30.5 92 31.1 26.1 31.6 Posted on Authorea 4 Mar 2021 — The copyright holder is the author/funder. All rights reserved. No reuse without permission. — https://doi.org/10.22541/au.161487405.53428023/v1 — This a preprint and has not been peer reviewed. Data may be preliminary. 5 4 3 Niches Foraging 2 1 Grp (DP). parameters deflection and stiffness for ranges with study this in species bird 2 Table Starling European Dipper Rufous-throated 64 Dipper White-capped 63 Kingfisher Half-collared 62 Trogon Narina 61 Swift White-rumped 60 Nightjar Rufous-cheeked 59 Coucal White-browed 58 Parrot Brown-necked 57 Turtle-dove Dusky 56 55 oaignce nacrac ihPgte l 22)frte4 ae idseisad1 land 12 and species bird water 49 the for (2020) al. et Pigot with accordance in niches Foraging Phalaropes and Curlews Plovers, Avocets, Oystercatchers, Plover, Crab Painted-snipe, Greater Jacanas, Limpkin, Flamingos, Ibises, Saddlebill, Storks, Hamerkop, Egrets, Herons, Ground Aquatic Skimmers and Skuas Birds, Frigate Petrels, Storm Petrel, Great-winged Aerial Aquatic Gulls Finfoot, Coots, Geese, Pelicans, Petrel, Grey Petrel, Blue Albatrosses, Surface Aquatic Terns and Gannets Plunge Aquatic Murres and Cormorants Petrels, Diving Grebes, Divers, Penguins, Dive Aquatic tru vulgaris Sturnus schulzi Cinclus leucocephalus Cinclus semitorquata Alcedo narina Apaloderma caffer Apus rufigena Caprimulgus senegalensis Centropus robustus Poicephalus lugens Streptopelia 3 1 4-23 935 2036 - 64 710 - 233 4 4 3-98328 968 - 93 276 202 549 - 1751 241 - 46 541 37 – 99 733 - 241 126.5 – 0.5 449 - 311 301 - 59 l range parameter Stiffness / r 10 ( range Parameter Deflection (10 713771 5. 0342.93 3169.64 535.62 2864.25 644.52 10.5 1962.02 744.21 619.94 6.3 17.7 20 352.9 24 25 382.5 6 35 13 743.2 451.1 25 7.10 30 7 718.6 7.80 25 25 682.9 11 103.7 447.8 6 466.7 7.90 81.6 5.37 12 93.15 14 9.57 17 7.72 79.9 9 12 7 126.9 7.02 13.5 89.4 7.72 18.3 100.5 6.16 14.8 8.29 137.7 13.3 103.7 16.7 109.3 20.5 20.1 15 l / r 6 ) einD (10 DP Median ) ³ ( r + d )/ r 6 ) Posted on Authorea 4 Mar 2021 — The copyright holder is the author/funder. All rights reserved. No reuse without permission. — https://doi.org/10.22541/au.161487405.53428023/v1 — This a preprint and has not been peer reviewed. Data may be preliminary. oysraeae ncnatwt ae.(ik,1970) (Rijke, water. with contact in area surface body 3 Table 11 10 9 Niches Foraging 8 7 6 Grp eos2 .83. 803. 48.0 – 35.2 47.5 – 39.0 98.4 58.3 – – 95.3 45.0 48.0 – 38.3 1.48 78.8 43.3 – – 63.6 32.5 27.0 25 2.84 1.40 0.66 32 30 25 Herons Gull Black-backed Ducks/geese Penguins Avg Family/species aiu egt o owtrpntaintruhadmnlfahr oprdwt egt per weights with compared feathers abdominal through penetration water no for weights Maximum n aiaTrogon Narina and Swifts Nightjars, Aerial/Sally Starlings and Cougals Parrots, Turtle-dove, Sandgrouse, Namaqua Sheathbill, Crane, Blue Francolins, Turkey, Wild Feeding Ground birds Land Ground Invertivore Screamer Horned Ground Aquatic Herbivore Ducks Surface Aquatic Herbivore Kingfishers Perch Aquatic ( μ )(g (kg/m (kg) m) Dikkops r . v tW e ufc raMx tfrn penetration no for wt Max. area surface per Wt Wt Avg 2 6 261 261 320 5 4 0 992605 3929 - 709 743 - 451 1228 127 145 13107 – 312 301 127 1333 – 353 145 301 306 328 383 l range parameter Stiffness / r 11 2 (kg/m ) ( range Parameter Deflection (10 l / r 6 ) einD (10 DP Median ) ³ ( r 2 ) + d )/ r 6 ) Posted on Authorea 4 Mar 2021 — The copyright holder is the author/funder. All rights reserved. No reuse without permission. — https://doi.org/10.22541/au.161487405.53428023/v1 — This a preprint and has not been peer reviewed. Data may be preliminary. hssuy ahnd i lutae h edn ih/needn ru nowihteascae bird associated the which into group niche/independent feeding the illustrates assigned. tip is node species Each study. this 1 Fig. hlgntcte eitn h hlgntcrltosiso 9autcbr pce ersne in represented species bird aquatic 49 of relationships phylogenetic the depicting tree Phylogenetic 12 Posted on Authorea 4 Mar 2021 — The copyright holder is the author/funder. All rights reserved. No reuse without permission. — https://doi.org/10.22541/au.161487405.53428023/v1 — This a preprint and has not been peer reviewed. Data may be preliminary. td.Ec oetpilsrtstefeignceidpnetgopit hc h soitdbr species bird associated the which into group niche/independent feeding the assigned. illustrates is tip node Each study. 2 Fig. hlgntcte eitn h hlgntcrltosiso 2ln idseisrpeetdi this in represented species bird land 12 of relationships phylogenetic the depicting tree Phylogenetic 13