Antipredator Behavior of American Avoget and Black-Necked Stilt Chicks

j. Field Ormthol., 53(4):315-325

ANTIPREDATOR BEHAVIOR OF AMERICAN AVOGET AND BLACK-NECKED STILT CHICKS

By T•:x A. SORDAHL

American Avocet (Recurvirostraamericana) and Black-necked Stilt (Hi- mantopusmexicanus) chicks are precocial,leave the nest within 24 h after hatching,and are flightlessfor their first 4-5 weeks.During this period they occur in open environments,where they are exposedto a variety of predators.The most important antipredatorstrategy of young avo- cetsand stiltsis to seek cover and hide or simply crouch (posturede- scribedby Hamilton 1975:88)in the openwhen dangerthreatens, and then rely on the aggressiveand/or diversionarybehavior of their parents. Chicks and especiallytheir parents are highly vigilant; this is probablyessential, in view of the large number of potentialchick predators and the inability of the parents to actually rout most of them (Sordahl 1981). Gibson(1971:452) noted that avocetchicks are very difficult to find when hiding, and that "hiding behaviorlasted until at leastthe third week,after which theyjust ran." In this paper I examine the antipredator behavior of young recurvirostridsand show that it differs betweenavocets and stiltsand varieswith age and contextin an apparently adaptivemanner.

STUDY AREA AND METHODS During the summersof 1977 and 1978, I studiedavocets and stiltsat 2 sitesin northern Utah: the BarrensCompany Hunting Club in Cache Countyand the Bear River Migratory Bird Refuge in Box Elder County. Both areas are managedby dredging, diking, and regulationof water flow. Their vegetationand topography are essentiallyidentical. The general aspectof these marshesis one of broad ponds <1 m deep, usuallybordered by dikes seldom• 1 m high. Vehiclescan be driven on the main dikes, which are paralleled by "borrow" channelsthat are often relativelydeep. The big pondslie on salt flats that are frequently exposed by fluctuating water levels. The flats become parched and crackedby June, water levelsdropping as the seasonprogresses. Vegetationis absentin many places.Salicornia spp. are the only plants growing on most of the salt flats. The Salicorniamay grow as a sparse coverof sprigs5-10 cm high or as widely-spacedsturdy bushes of 20- 40 cm height and 40-70 cm diameter.On someof the drier areasa few greasewood(Sarcobatus vermiculatus) shrubs occur. The dominant plant along channelsand other relatively stablewater boundariesis desert saltgrass(Distichlis stricta), which growsin densemats and reaches15- 40 cm in height. In parts of the Bear River Refuge and at the edge of the Barrens,more typical"marsh" vegetation occurs--e.g., cattails (Ty- pha spp.),rushes (Scirpus spp.), sedges (Carex spp.), and reeds(Phragmites communis).However, neither adult recurvirostridsnor their young reg- ularly use suchhabitats.

315 316] T.A. Sordahl j. k•elclo, ni,lml. Auttlnln 1982

I banded172 young avocets and 120young stilts. Of these,49 avocets (33 nestlings,16 older chicks)and 51 stilts(18 nestlings,33 older chicks) were captured at the Barrens; captureswere made opportunistically during daily field work and during 42 h of nightlightingon 17 nights. The remaining 123 avocetand 69 stilt chickswere capturedat the Bear RiverRefuge. Weekly trips were madeto the refuge oncehatching had begun.I searchedfor chicksby drivingthe dikesin an automobile;an assistantwatched the broodswith binocularsor spottingscope while I approachedthem, then directedme to their hiding placeswith hand signals.A smallboat was used to negotiatethe deeperwaterways. Each chick received a U.S. Fish and Wildlife Service band (on the tibio-fibula),which quickly became dull-colored and difficult to seein the field. Sincecolor bands might reduce the ability of chicksto hide from predators,only 2 avocetand 6 stiltchicks that werecaptured near fiedgingwere color-banded.Eighteen avocet and 15 stilt chickswere recapturedprior to fiedging. I attemptedto recordthe followingdata for eachyoung bird captured: (1) speciesand estimatedage; (2) time of capture;(3) what sub- strateit wascaptured on; (4) whetherit tried to hide whenapproached or simplyran; (5) whetheror not it calledwhen captured.I measured the wing chord of each chick to the nearestmillimeter with vernier calipers.Age estimateswere basedon personalexperience and the knowledgethat fiedging normally occursat ca. 28 days.Since I never misjudgedthe ageof a recaptureby > 1 day (mostrecaptures had been bandedoriginally during their hatching day and weretherefore of known age), I believethe age estimatesare accurateto +2 days. Wheneverwater of sufficientdepth waslocated near a capturesite, I testedthe underwaterswimming ability of chicks.Each bird wasplaced in the water and givena standard"scare treatment" that consistedof my wadingafter and reachingfor it; it wasthen classifiedas either a diver or nondiver. Dive durations were timed to the nearest. 1 sec with a stopwatch.I pacedthe distancebetween submergence and emergence pointsalong the chicks'underwater paths, and convertedthe pacesto meters(I had earlier calibratedmyself for accuracyand consistencyby pacinga footballfield while wearinghip boots;during 12 trialsI paced the 100 yd in 123 to 125 paces,so 124 pacesper 100 yd wasused as a standard).Most chickswere given 3 diving trials, in rapid succession, and the bestperformance was used for calculations;distance and du- ration usuallydecreased on consecutivedives.

RESULTS AND DISGUSSION Diurnal rs. nocturnalescape behavior.--The habitats where avocetand stiltchicks were captured in the daytimediffered from thosewhere they werecaptured at night (Fig. 1; althoughthe data for both speciesyield highly significantX 2 values,the statisticaltest for avocetsmay not be validbecause of the low expectedfrequencies at night).During the day I usuallycaught chicks hiding in grassor, lesscommonly, crouching on Vol.•, •,) 4 Avocetand Stilt Chick Behavior [317

DAY NIGHT 1oo

• so

o avocets stilts avocets stilts n: 116 n=89 n=? n=35

HABITAT FIGURE1. Percentof AmericanAvocet and Black-neckedStilt chickscaptured in 3 hab- itatsduring the day and at night. Open barsrepresent open water, shadedbars mud flats,and blackbars vegetation.

open mud fiats;a smallpercentage, usually very youngchicks, crouched in shallowexpanses of open water, and a few older chickstook refuge in deep water (seesection on aquaticescape behavior below).At night, on the other hand, chickswere caughtalmost exclusively in shallowopen water. This pattern couldbe explainedby the fact that chickshiding in the grasswould be extremelydifficult to find at night (despitethe fact that they are alsomore difficult to find in grassthan on mud or water in the daytime). However, it seemedpeculiar when a 1-day-oldavocet brood that I caughtcrouching in the water at night repeatedlyscrambled out to lie fiat in the water each time I placedthem in the grass.My subse- quent capture of so many chicksat night in open water led me to con- sider severalfactors which would promote this behavior (I doubt that chicksroost in the water, as someadults do, at leastuntil they are near fiedging). The overriding factor must be that chicksare lessinhibited by the danger of visualpredators to move about or crouchin the open at night. Twenty-fivepercent (30/118) of avocetchicks captured in the daytime and 43% (3/7) of those capturedat night tried to escapeby running. Eleven percent(10/91) of stilt chickscaptured in the daytime 318] T.A. Sordahl j. FieldOrnithol. Autumn 1982 and 70% (23/33) of thosecaptured at night tried to escapeby running (X2 = 39.79, 1 dr, P < .001). Probably chickswere both more likely to run and lesslikely to be discoveredif hiding at night. The increased tendency to run at night could be explained by the chicks'reduced abilityto seethe predator,if this is the stimulusrequired to causechicks to hide. A proximate explanationof the behavior leading to a large number of capturesin the water at night might be that, under cool nighttime air temperatures,chicks seek the water for warmth when disturbances preventtheir parentsfrom broodingthem. Low temperaturesat night tended to increase chick movement. Small chicks became chilled and chasedtheir parentsin order to be brooded;activity may alsoserve to generatebody heat. Possiblythe youngdo somefeeding in the water at night, but their apparentinability to withstandnighttime temperatures without frequent brooding makesthis an unlikely explanationfor at least the first 2 weeks. Nocturnal releasefrom danger by visualpredators permits chicks to activelyescape from a disturbancecenter. Thus an ultimateexplanation, in viewof the muchgreater importance of olfactorypredators at night, is that the behaviorcould be adaptivebecause: (1) water would not hold the chicks'scent and would therefore be a safer hiding placeor escape route than solid ground or vegetation;(2) water-coveredareas have fewerobstructions than vegetatedareas and thusprovide a fasterescape route. The beststrategy to elude olfactorypredators searching an area at night may be to move to water and crouch(young chicks)or escape to another area (older chicks).Auditory cuesare probablyreduced by the loud callingand splashingof the parents. The loud behaviorof parentswas much more localizedaround their chicksat night than during the day. This and the chicks'greater activity enabledme, as a visualpredator with a flashlight,to find chicksquite readily at night. Avocetvs. stilt escape behavior.--Avocet and stilt chicksare quite similar at hatching,but a stilthatchling is somewhatsmaller, has relatively longer legs,unwebbed feet, and slightlydarker down with blackmarkings that are more distinct.The lessaquatic stilt chick frequentsvegetation, where its darker colorationand more distinctmarkings match the rel- ativelydark backgroundand shadows;while the youngavocet occurs in the sameplaces, it has a greater tendencyto forage on open flatsand ponds,where its paler plumagematches the washed-outbackground (see also Hamilton 1975:14 for habitat differences in these species). During the day I caughtmore stiltchicks than avocetchicks in vegetation (Fig. 1; X2 = 10.47, 1 df, P <.005); conversely,I caught more avocet chicksthan stilt chickson mud flatsand open water. These habitat differencesbecame more pronouncedas the young attainedtheir juvenal plumages--stiltstended to staynear vegetation, and avocetstended to venture into the open.Juvenile stilts have brown edging on the dorsal feathers that producesa scalycryptic pattern, Vol.53, No. 4 Avocetand Stilt Chick Behavior [319

61 1oo 12 22

Stilts

Bvocet$ 21 15

I _ I I l

I -7 8 - 14 15 - 21 22 - 28

AGE CLASS (DAYS) F•CURE2. Percent of American Avocet and Black-neckedStilt chickscaptured during the day that tried to escapeby hiding rather than running. Samplesizes for eachage class are indicated next to the circles. whereasjuvenile avocetshave a black-and-whitechevron pattern dorsally (like that of adults)and are relativelyconspicuous when hiding in grass. Escapebehavior data are consistentwith this changein the relativeabil- ity of the 2 speciesto hide effectively.During the first weekyoung of both speciesnearly always tried to hide whenapproached in the daytime (Fig. 2; nighttime capturesare omitted becausedarkness and low tem- peraturesdecrease a chick'stendency to hide; see precedingsection). During the secondweek more chickstried to run, probably because increasingstrength and speedimproved their chancesof escapeby this method, while increasingsize lowered their chancesfor successfulhid- ing; the samplesize is too smallfor valid statisticaltesting, but it appears that avocetsran more frequentlythan stilts.During the third (X2 = 8.75, 1 df, P < .01) and fourth (X2= 2.59, 1 dr, P = .11) weeks, i.e. when juvenal plumagewas attained, avocet and stiltescape behavior diverged more strongly,with stiltstending to hide and avocetstending to run. It is not clear whether this speciesdifference is determined by habitat selectionand therefore availabilityof hiding places,or whether a psy- chologicaldifference in hiding tendencyexists. The function of vocalizations of avocet and stilt chicks is not known, but avocetchicks were noticeablymore vocal.At night callsoften seemed 320] T.A. Sordahl j. FieldOrnlthol. Autumn 1982 to connotediscomfort, and probablyfunctioned as a locationsignal and/ or summonsto the parentsto brood the young. During the day 79% (85/108) of avocetchicks but only 39% (35/89) of stilt chickscalled when captured(X 2 = 30.14, 1 dr, P < .001). Assumingthat the callsmay elicit antipredatorbehavior from adults,this speciesdifference can be inter- pretedin 2 non-mutuallyexclusive ways. First, avocets are more strongly colonial and more socialthan stilts (pers. obs., Hamilton 1975); thus callingcould be adaptiveif it enablesa chickto evokethe aid of unre- latedconspecifics. Adult avocets(and stilts)might be selectedto respond to the callsof nearbyunrelated chicks if doing so enhancesthe survival chancesof their own young. Sinceparents guard their young closely, they are aware of threatsto them, and the young stilt might often be better off to remain silentif additionalhelp is unlikely to be near (e.g., if chick calls also sometimesattract predators). Second,silence seems more compatiblewith the hiding behaviorof stiltsthan with the running behaviorof avocets.All (9/9) stiltsthat attemptedto run when captured alsocalled, whereasonly 32% (26/80) of stiltsthat tried to hide when capturedgave calls (X 2 = 12.75, 1 dr, P < .001). However,avocets were equallylikely to call if they were hiders(76%, 62/82) or runners(88%, 23/26; X2 = 1.25, 1 dr, P > .25). Possiblya running stilt chickwould be more likely than a hider to enter the domainof other defendingparents, and thus would benefit from calling to elicit their antipredator responses.A hiding stilt chickthat is vocalwhen capturedwould alsobe more likely than an avocetchick to attractpredators to hiding placesof siblings,because siblings often hide in the samegeneral area but the probabilityis higher that an avocet'ssiblings would be running instead of hiding. Answersto thesequestions await detailed study of the social contextof chickpredator responses and explicationof the effectsof the chicks'calls on conspecifics. Aquaticescape behavior.--Avocet and stiltchicks are capableswimmers, and readilytake to water as soonas their down is dry. Webbedfeet and shorter legs make avocetsbetter swimmers than stilts (adult stilts rarely swim and are relatively awkward when they do). When ap- proachedby predators,chicks sometimes swim away from shore,espe- ciallyif it offerslittle cover(pers. obs., Hamilton 1975:88).This behavior becamemore commonin avocetchicks during their third and fourth weeks,probably because their increasingsize and plumageconspicu- ousnessrendered hiding less effective;some of these young avocets simplyretreated to deeperwater when I chasedthem, and then waited. When I reachedfor them they often dove (cf. Sumner 1931 for stilts, and Gibson 1971:452for avocets),emerging again somedistance away. No chicks lessthan 24 h old dove, but beyond that age many did. Diving only occurredin water deeper than a chick'swading depth. Avo- cetsand stilts propel themselvesunderwater mainly with shallowsyn- chronouswingbeats, but they often kick their legs vigorouslyas well. Divesare to a depth of only ca.. 1-.4 m. Underwaterpaths are usually straight,but sometimescurve as much as 90ø . Young avocetswere more likely than stiltsto dive, and they achieved Vol.53, No. 4 Avocetand Stilt Chick Behavior [321 better underwater performances.Sixty-three percent (30/48) of avocets were divers, whereasonly 32% (6/19) of stiltscould be induced to dive (X2 = 4.07, 1 dr, P < .05). Avocet divesaveraged 6.0 sec(n = 30, SD = 2.6, range = 2.3-12.8) and stilt divesaveraged 4.2 sec(n = 6, SD = 1.4, range = 3.0-6.6). Avocetsswam an averageof 3.8 m (n = 28, SD = 1.6, range = 1.5-7.4) underwaterrs. 2.2 m (n = 6, SD = 0.8, range = 1.1- 3.0) for stilts. Underwater swimming speed for avocetswas .64 m/sec (n = 28, SD = .13, range = .42-1.06) rs..55 m/sec (n = 6, SD = .22, range = .37-.99) for stilts.The avocet/stiltcomparisons for diving time, distance,and speedare statisticallynonsignificant, but the trend suggests a greater diving proficiencyin avocets. The tendencyof a chick to dive should depend largely on: (1) its diving ability,and (2) its availablealternatives for escape.This may ex- plain why the lessaquatic stilt is lesslikely to dive. Downy chicksare poor divers, largely becausethey have too little wing area for propul- sion;in fact they often are unableto submergecompletely. Thus young chicksmight be expectedto dive only rarely, and to simplyswim away from predatorswhen in the water; the tendencyto dive shouldincrease with age and ability. My observationssupport these expectations(Fig. 3; avocetX 2 = 13.83, 3 dr, P <.005; stilt sample too small to test statis- tically),assuming that different-agedchicks perceived the human threat stimulussimilarly. The underwater swimming speed of avocet chicks appearsto increasecontinuously with wing size (Fig. 4), and henceage, but underwater distance(Fig. 5) and tendencyto exhibit diving (Fig. 3; X2 = 3.14, 1 dr, P = .08) seemto declinelate in the chickstage. In view of the dissimilarselection pressures for flying in air and in water (Storer 1971:153),it might be expectedthat underwaterability would decrease as the paddle approachesits ultimate use as a wing. My data do not showthis clearly,possibly because they are too coarse,or becausethe birdsadjust their wingarea underwater;perhaps the increasingstrength of the chicks'flight musclescompensates for any decreasein efficiency of the paddle. The apparent decline in the diving responsemay be concomitantwith a shift toward or maturation of the aerial flight re- sponse(to a human predator). Diving behaviorwould be effectiveagainst many kinds of predators. Even well-trainedhunting dogs have great difficulty locatingflightless ducksthat dive in shallowwater, becausethey concentratetheir atten- tion on the submergencepoint (pers. obs.). Other non-aquaticmam- malian predatorswould probably be no lessconfused. Remaining on the water and diving may be a better strategythan flight againstsome raptors.Many prey speciesare reluctantto fly when a PeregrineFalcon (Falcopereg'rinus) is around (Cushing 1939:107, Meinertzhagen 1959: 152). The importanceof avocetsin the diet of Peregrineand Prairie (?. mexicanus)falcons (Porter and White 1973) suggeststhat divingbehavior is a significantpart of their antipredator repertoire. Diving should be effectiveagainst falcons (R. D. Porter pers. comm.), but it is not totally effective--Peregrineshave been seen killing swimmingducks and seiz- ing wooden decoysoff the water (Cushing 1939:103; Meinertzhagen 322] T.A. Sordahl j. FieldOrnithol. Autumn 1982

100 10

Savocets

ß SO

/ - stilts zød / o 20/ I I i i 1-7 8-14 15-21 22-28

AGE CLASS IDAYSI

FIGURE3. Percentof American Avocet and Black-neckedStilt chickscaptured that dove when pursued closelyin the water by a human. Sample sizesfor each age classare indicated next to the circles.

1959:152,153), and they prey heavily on Eared Grebes (Podicepsnigri- collis)in the Gulf of California (R. D. Porter pets. comm.). Among the shorebirdsdiving behavioris seenonly in an antipredator context. Several observationsindicate that diving is a tactic employed successfullyagainst aerial predatorsby both young (Pettingill 1976:39) and adults (Osgood1909:36, Stone 1925, Kelso 1926, Martin and Atke- son 1958, Meinertzhagen 1959:95, 135, Nethersole-Thompsonand Nethersole-Thompson 1979:182). Diving by adults is most commonly seen when they are surprised at close quarters (Sutton 1925) or are wounded (Miller 1918, Kelso 1926, Bent 1929:87), situationsthat are likely to be associatedwith raptor attacks.Thus diving is probablyused by many shorebirdspecies when the wing area of individualsis sufficient for underwater propulsionbut aerial flight (the primary mode of escape) has not yet been attained, or has been lost or otherwiserendered ineffective.

SUMMARY

American Avocet and Black-necked Stilt chicks crouch or hide when danger threatens,and then rely on the aggressiveand/or diversionary behaviorof their parents.Chicks exhibited different escapebehavior at Vol•3. xo 4 Avocetand Stilt Chick Behavior [323

1.00

0 0 0 0 0 • 0 • .60 o •• o o o. • o o

o ß

.2O

20.... 40 6; t ;0 i 100i i 120i , 140, , 160i I 180i

Left Wing Chord (mm) F]C•'RE4. Underwaterswimming speed of AmericanAvocet (open circles) and Black- neckedStilt (solid circles) chicks as a functionof wingsize. Linear regression equation for theavocet data is: y = .5112+ .0013(x). Correlation coefficient r = .48;t = 2.55, 22 df, P < .05.

o • o o o • ß o o o • O• 0 ß ß¸ ß o

t i I I I I I I I I ' i t I I I I 20 40 60 80 100 120 140 160 180

Left Wing Chord (mm) F](;•'i•E5. Underwaterswimming distance of AmericanAvocet (open circles) and Black- neckedStilt (solid circles) chicks as a functionof wingsize. Curve fitted for avocet databy step-up polynomial computer program to the equation: y = -.2934+ .0787 (x) - .0003(x2). Correlation coefficient r = .54;t = 3.03,22 df, P < .01. 324] 7•. A. Sordahl j. FieldOrnithol. Autttmn 1982 night than in the daytime.At night, releasefrom dangerby visualpredators may allow chicksto actively escapefrom a disturbancecenter. Other factors,such as low temperatureand inabilityto seethe predator increasethe activityof chicksat night whena disturbanceprevents parents from brooding them. An apparent tendencyto "hide" in shallow water or to crossstretches of water at night may representa strategyto avoid scent-orientednocturnal predators,and merits further study. During their first week,avocet and stiltchicks nearly alwaysattempted to hide when approached,whereas in subsequentweeks many tried to run away. During weeks2, 3, and 4, avocetand stilt escapebehavior diverged,with stiltstending to hide and avocetstending to run. This species'difference may be relatedto the greatertendency of avocetchicks to forage in open areas,and to their lesscryptic juvenal plumage,both of which render hiding lesseffective. Avocet chickswere more vocal than stilt chickswhen captured, but the explanationis not clear. Avocetand stilt chickscan swim 1-2 h after hatching.After the first 24 h many chicksdive when pursued in the water. Chickspropel themselvesunderwater with their wings.Thus underwaterswimming ability was positivelycorrelated with wing size and age. Avocet chickswere more likely to dive, and they swamfarther, faster, and stayedunder- water longer than stilt chicks.Diving is probablyeffective in eluding many kinds of predators.

ACKNOWLEDGMENTS I thank Keith L. Dixon and MarshallA. Howe for helpful suggestions on this paper. Ja•nesT. Bowman, Bartie K. Gilbert, Ivan G. Pahnblad, and Allen W. Stokesread an earlier version.I am grateful to Kathy Fite, Richard D. Porter, and Kimberly G. Smith for discussionsand technical advice, and to Debra A. Tirmenstein for field assistance on chick-band- ing trips to the Bear River Refuge. Jack B. Parson and Ned Peabody .grantedpermission to conductresearch at the BarrensCompany Hunt- •ng Club and the Bear River MigratoryBird Refuge,respectively. This researchwas supportedby grants from the Frank M. Chapman Me- morial Fund of the American Museum of Natural History and from SigmaXi, The ScientificResearch Society.

LITERATURE CITED

BENT, A.C. 1929. Life histories of North American shorebirds. Part II. U.S. Natl. Mus. Bull. 146:1-340. CUSHINC.,J. E., JR. 1939. The relationof someobservations upon predationto theories of protectivecoloration. Condor 41:100-111. GIBSON,F. 1971. The breedingbiology of the AmericanAvocet (Recurvirostra americana) in central Oregon. Condor 73:444-454. HAMILTON,R.B. 1975. Comparativebehavior of the American Avocetand the Black- neckedStilt (Recurvirostridae).Ornithol. Monogr. 17:1-98. KELSO,J. E. H. 1926. Diving and swimmingactivities displayed by the Limicolae.Auk 43:92-93. M^RTIN,L. M., ^NDT. Z. ATKESON.1958. Escapediving by a SpottedSandpiper. Wilson Bull. 70:281. VoL•:•, No 4 Avocetand Stilt Chlck Behavior [325

MEINERTZHAGEN,R. 1959. Piratesand predators.Oliver and Boyd, London. MILLER,m. 1918. A surprisingtrait in the Black-neckedStilt. Condor 20:126. NETHERSOLE-THoMI'SON,D., AND M. NETHERSOLE-THOMPSON. 1979. Greenshanks. Bu- teo Books, Vermillion, South Dakota. Os(;ooD,W. H. 1909. Biologicalinvestigations in Alaskaand Yukon Territory. North Am. Fauna No. 30.' 1-96. PETTINGILL,O. S., JR. 1976. Observedacts of predation on birds in northern lower Michigan. Living Bird 15:33-41. PORTER,R. D., ^ND C. M. WHITE. 1973. The Peregrine Falcon in Utah, emphasizing ecologyand competitionwith the Prairie Fai::on.Brighain Young Univ. Sci. Bull. Biol. Ser. 18:1-74. SORD^HL,T.A. 1981. Sleightof wing. Nat. Hist. 30(8):42-49. STONE,W. 1925. Diving of the SpottedSandpiper. Auk 42:581. STORER,R.W. 1971. Adaptive radiation of birds. Pp. 149-188 in Avian biology,Vol. 1 (D. S. Farnet and J. R. King, eds.), AcademicPress, New York. SUMNER,E. L., JR. 1931. Someobservations on bird behavior.Condor 33:89-91. SUTTON,G. M. 1925. Swimmingand diving activityof the Spotted Sandpiper (Actiris macularia). Auk 42:580-581. Departmentof Biologyand The EcologyCenter, Utah StateUniversity, Logan, Utah84322. (Currentaddress: Department of Biology, Luther College, Decorah, Iowa 52101). Received19 Jan. 1982; accepted3 Aug. 1982.

NOTES AND NEWS

Bird EvolutionSymposium.--The Zoology Departfiaent of Ohio WesleyanUniver- sit)'will host a symposium,"Evolution of birds:processes and products." The symposium will be held Friday,15 April 1983,beginning at 9:30A.M. andcontinuing throughout the day.Speakers will include:Alan Feduccia, Richard F. Johnston,George F. Barrow- clough,William R. Dawson,and Glen E. Woolfenden.Meals will be arrangedin con- junctionwith the symposium.Overnight accommodations can be arranged.For further informationplease contact: Edward H. Burtt,Jr., Departmentof Zoology,Ohio Wesleyan University,Delaware, OH 43015 (614-369-4431, ext. 400).