Vocalizations of Common Ravens in Virginia

The Condor87:379-388 0 The CooperOrnithological Society 1985 VOCALIZATIONS OF COMMON RAVENS IN VIRGINIA

RICHARD N. CONNER

ABSTRACT. -1 tape recorded 1,2 10 vocalizations and observed the behavior of Common Ravens (Corvus corux) in southwestern Virginia from 1972 through 1976. Eighteen call types were identified and observed in conjunction with behavior at a communal roost, a landfill, and nest sites. I speculate that different call types were associatedwith excitement, agonisticinteractions, aggression,alert, courtship, submission, and thwarting. Common Ravens in Virginia and hand- reared, captive ravens in Germany shared six call types, suggestingthat the use of these call types may be innate. Although Common Ravens in Virginia, Alaska, and Germany gave many similar call types, locally learned call types may be present in each geographic area. Numbers of shared call types suggestthat vocal behavior of ravens in Virginia resembles that of other North American ravens more than European ravens.

The diversity and complexity of Common Ra- Europe. I was particularly interestedto seehow ven (Corvus corax) vocal behavior have in- Gwinner’s (1964) findings on hand-reared, terestedornithologists and ethologistsfor years. captive ravens applied to wild ravens. Such Although ravens may be locally numerous at comparisons may provide insight on deter- food sources, such as dumps (Mylne 196 1, mining which aspectsof raven vocal behavior Dorn 1972, Brown 1974, Conner et al. 1975) are innate and which are learned. and at communal nocturnal roosts (Cushing 194 1, Coombes 1948, Lucid and Conner 1974), STUDY AREA their populations are typically of low density, My study area (2,500 km2) was located in por- especially during the nesting season (Hooper tions of Botetourt, Craig, Giles, Montgomery, et al. 1975). Their sparsity in number, coupled Roanoke, and Rockbridge counties of south- with their high intelligence (Bent 1946, Knight western Virginia. This area is in the Appala- and Call 1980, Bruemmer 1984) extreme war- chian Oak Forest plant associationof the East- iness, and frequently inaccessible nest sites, em Deciduous Forest Province (Bailey 1978) make it difficult to record their vocalizations and the Ridge and Valley Physiographic Re- within social context. Gwinner (1964) at- gion (Fenneman 1938), where elevations range tempted to overcome these obstaclesby study- from 460 to 1,360 m above sea level. Vege- ing hand-reared, captive ravens, but normal tation in most of the study area is oak (Quercus behavior and related vocalizations could have spp.)-hickory (Curya spp.) forest, with occa- been altered by captivity. sional pine (Pinus spp.) stands scattered over Studies in North America by Dorn (1972) the entire area on portions of north-facing and Brown (1974) included some aspects of slopes. The study area included a nocturnal, Common Raven vocal behavior. Dorn re- communal roost of ravens in Giles County at corded and made audiospectrogramsof sev- an elevation of 1,350 m, where yellow birch eral different vocalizations, but he was unable (Betula alleghuniensis)and eastern hemlock to detect distinct behavioral associationswith (Tsugu cunudensis)were the dominant cover them. Brown (1974) recorded and made au- species(Lucid and Conner 1974). diospectrogramson about 25 different vocalizations and described,in detail and when pos- METHODS sible, display postures associatedwith many I studied raven vocal behavior from January, of the calls and their behavioral context. 1972, through May, 1976. I recorded most data The Common Raven population in the cen- within 1 h of dusk during late fall and winter, tral Appalachians is disjunct from the rest of 1973, from the concealment of a blind 30 m the population in Canada and the United States from the base of the communal roost. During (AOU 1983). Thus, vocal behavior of Com- March through May, 1972 to 1975, I observed mon Ravens in Virginia may differ from other raven behavior and recorded vocalizations at North American populations as well as from six different neststhat were within an area 100 those in Europe. I sought to document the km to the northeast and 35 km to the east of vocalizations and their social context in these the communal roost. Additional observations birds, and compare my observationswith those and recordings were made from a blind at a of comparable studies in North America and sanitary landfill that was 15 km southeast of

[3791 380 RICHARD N. CONNER

TABLE 1. Means and standard deviations of variables measured on eight calls vocalized by Common Ravens in southwesternVirginia.

Call type # recorded Highest freq. (Hz) Lowest freq. (Hz) Call duration(s) Hammnics #

Caw 358 1,840 t 19 245 + 3 0.223 * 0.003 1.91 * 0.04 Growl-like 292 1,830 f 20 240 t- 3 0.278 ? 0.005 - Whine 337 1,660 * 23 280 t- 4 0.240 ZL0.007 2.84 + 0.05 Rattle 10 1,430 + 88 600 4 112 0.680 _t 0.067 - Cawlup 8 1.690 + 111 220 t 20 0.248 -t 0.018 1.63 + 0.26 Staccatocaw 5 (450 + 25 240 +- 5 0.120 * 0.003 1.89 t 0.03 Awk 35 1,660 * 70 260 +- 16 0.232 IL 0.014 1.40 & 0.18 Cluck 109 1,810 & 30 550 +- 36 0.087 ? 0.004 1.01 + 0.11 Kow 1 7,000 950 0.270 7 Bell-like 8 1,020 -I 152 360 +- 76 0.365 + 0.099 0.25 f 0.31 Ku-uk-kuk 1 4,000 600 0.680 - Ko-pick 10 1,075 * 20 600 +- 20 0.187 f 0.008 - Ank-up 8 1,440 + 41 630 t 150 0.271 -t 0.035 0.25 + 0.16 woo-oo-woo 1 1,000 400 0.510 Uvular 2 1,000 900 0.110 - 0-ot 1,700 550 0.250 Puddle 1,200 550 0.170 1 Ke-aw 2: 1,780 t 64 255 +- 6 0.226 + 0.004 1.15 + 0.08 the roost. Whenever possible, I made obser- Ravens gave other call types in more than one vations and recordingsof ravens soaringabove context. Call types with simultaneous behav- the many mountain ridges in the study area. ioral observations are described in order of Many of the foregoing observations on bird decreasing frequency of occurrence. My ob- behavior were made without tape recording servations on behavior only report occasions concurrent vocalizations, as well as the re- when I also heard a call. They do not include verse. instanceswhen particular behaviors were ob- When watching pairs of ravens at nest sites, served without vocalizations. Thus, the num- I always assumedthe larger bird to be the male bers document my findings, but have little (Willett 1941, Coombs 1978). I usually could comparative value. not determine the sex of ravens at the roost becauseof their number and movement. I did THE CA W (FIG. la) not attempt to distinguishbetween females and The caw was a loud, hoarse sound,given singly non-breeding young ravens because of their or repeated many times. The raven’s cuw morphological similarity. soundedsimilar to that of the American Crow I used a l-m diameter parabolic reflector (Corvus bruchyrhynchos),but was much lower and Uher 4000 report-IC or Panasonic RQ- in pitch. It varied in pitch and duration, per- 2035 tape recorders at a tape speed of 9 cm/s haps in relation to the age and sex of the bird to record vocalizations. Sonagramswere pro- or the intensity of the stimulus eliciting the duced with a Sona-graph 7029-A on the wide call. Some cuwsaudibly ascendedin pitch while band setting of the linear frequency scale. All others descended. I tape-recorded 358 of the sonagramswere made using the 40-4,000 Hz 536 caw~ I heard (Table 2). range. To quantify calls, I measuredthe highest Context-Z. Caws were the most common and lowest frequency (Hz), the length (s), and vocalizations of single ravens and small flocks the number of harmonics above the funda- of ravens that were observed soaring above mental frequency of each call (Table 1). I clas- mountain ridges (189 instances),flying above sified the soundsinto various call types based or perched in the communal roost (146 oc- on their sonagraphic appearance and on my casions),or flying above a sanitary landfill, ap- ability to distinguish them in the field. parently trying to see if the area was safe to land and begin foraging in the garbage(35 in- RESULTS stances). I tape-recorded I ,2 10 Common Raven vocal- Context-2. Cuwswere the most frequent izations (18 call types) and made concurrent call when I disturbed ravens at nest sites (72 behavioral observations on 972: 521 obser- observations). When young were in the nest, vations at the communal roost, 222 on moun- cuws given by a single raven usually caused tain ridges throughout the study area, 180 at the bird’s mate to return to aid in defense of nest sites, and 49 at the landfill. The social the nest. On one occasion,I noted that the cuw context of some call types was discernable be- of the presumed female of the pair was slightly cause they were elicited by particular stimuli. higher-pitched than that of the male. COMMON RAVEN VOCALIZATIONS 381

a b C d - I- GROWL- LIKE I CAW

e f g h - WHINES I RATTLE

4 i i

3 CAWLUP - STACCATO CAW -

I” 2 Y

i 2 3

SECONDS

FIGURE 1. Vocalizations given by Common Ravens in Virginia: a-the cuw; b, c, and d-growl-like sounds;e, f, and g-whines; h-the rattle; i-the cawlup;and j -staccato caw.

Context-3. On four occasions,several ra- Context- 1. I heard these soundsat the roost vens, possibly immatures, gave caws while as the ravens were finding positions in trees to “playing” and pursuing each other above the spend the night. In each instance, one or both roost for the possessionof a twig or similar, of two ravens trying to get the same roost po- apparently useless,object. sition gave growl-like sounds. I could not see Context-4. “Spectator” ravens gave caws clearly which was the aggressor. while they watched agonisticactivities of other ravens near them (90 instances).Although no WHINES (FIGS. le, f, and g) feathers were displayed with this vocaliza- Whines were soft calls and sounded much like tion, unspread wings were slightly raised and the mono-pitched, or on occasion, the multi- the raven’s head usually bobbed noticeably harmonic whine of a dog. I made behavioral while the call was given in this context. observationson 5 1 of the 337 calls I recorded. GROWL-LIKE SOUNDS (FIGS. lb, c, and d) Context- 1. I heard this call only at the roost These sounds were loud and harsh; they had in what appeared to be agonistic confronta- a pulsing, growl-like quality. Although I re- tions over position in the roost trees. Individ- corded 292 growl-like sounds, I saw concur- uals giving the call appeared to retreat from rent behavior on only 97 occasions. an apparently dominant raven. 382 RICHARD N. CONNER

TABLE 2. Summary of Common Raven call types and their behavioral context,

Number of calls with Call type Figure number behavioral contexts Behavioral contexts

Caw la 536 Conflict, aggression,excitement, alert, play, unknown Growl-like lb, c, d 91 Aggression Whine le, f, g 51 Conflict, submission Rattle lh 49 Courtship, associatedwith pairs Cawlup li Unknown, possibly a location call Staccatocaw lj z: Alert Awk 2a 30 Unknown Cluck 2b 29 Distress, thwarting Kow 2c 27 Aggression,attack call Bell-like 2d, e 21 Courtship, associatedwith pairs Ku-uk-kuk 2f 18 Aggression,chasing another raven Ko-pick 16 Pair associated,unknown Ank-up % 6 Pair associated,unknown woo-oo- woo 2i 0 Unknown Uvular 2j 2 Unknown 0-ot 2k 1 Unknown Puddle 21 4 Unknown Ke-aw 2m 4 Unknown

THE RATTLE (FIG. lh) Figure lj representsa typical staccatocaw (0.25 Rattle calls resembled the territorial drum- s) followed (1.3 s) by two longer caws.Varia- ming of Downy Woodpeckers (Picoidespu- tions on this basic call either increased the bescens),but were about twice as loud. I re- number of cawsfollowing the initial sharp caw corded 10 of the 49 rattle calls I heard. or totally eliminated them. I recorded 5 of the Context-I. Ravens gave rattle calls during 35 staccato cawsI heard. courtship (49 occasions)at the roost, the san- Context--I. These calls were the first to be itary landfill, and nest sites. During the rattle given on nine of 39 occasionswhen I disturbed call, ravens arched their neck and pointed their pairs at their nests.Ravens gave staccatocaws bill downward with the tip spread about 7 to on 15 of 24 occasionswhen flushed from the 8 cm in a gaping,or choking, action. Typically, roost. Figure lj showsthe call given by a raven leg and throat feathers and all the head feathers when a Golden Eagle (Aquilachysaetos) dived were ruffled and displayed during this vocal- at the roost just before nightfall and flushed ization. I heard the rattle call throughout the the ravens. Ravens gave staccato cawsat the year, but most frequently during the breeding sanitary landfill on 11 of 32 occasionswhen season. The bell sound (Figs. 2d and e) was they were flushed by dogs, humans, or trucks. often given in conjunction with the rattle. THE A WK (FIG. 2a) THE CA WLUP (FIG. li) This call was harsh and low in frequency. Of The cawlupcall was moderately loud and I 35 awksrecorded, I observed concurrent be- could hear it at distancesof several kilometers havior for only 30. if the raven was soaring above a mountain Context- I. On 28 separateoccasions, the awk ridge. This call resembled the caw (Fig. la), call was given singly by ravens in roost trees. but had a two-syllable sound. I was able to I did not detect any response from other ra- record only 8 of the 38 cawlupsI heard while vens. watching individuals. Context-2. On two occasions,the awk call Context- 1. I heard this call during aerial wasuttered by one raven while chasinganother. courtship on 15 occasions.On four occasions, The call was repeated twice in both of these the caller’s mate replied with the ank-up call instances. (Fig. 2h). Context-2. Single ravens gave cawlupsas THE CLUCK (FIG. 2b) they soared above mountain ridges (12 cases), Typically, ravensgave a seriesof staccatoclucks or while flying above the roost (11 cases).The in couplets(Fig. 2b). Occasionally, four to nine call was usually repeated two or more times. cluckswere given in rapid succession.Each cluckhad a sputter-like quality. I observed the STACCATO CA WS (FIG. 1j) behavior associatedwith 29 of the 109 clucks This call resembles the caw (Fig. la), but is recorded. about one-half as long in duration (Table 1). Context-I. I heard clucks on 17 occasions COMMON RAVEN VOCALIZATIONS 383

* 4 a b f‘ “!’ d

3, CLUCKS BELL- LIKE AWK I” 2. ’ \ Y I

1 ’ Cs.1 If d b I I” KOW

, 4 e

BELL- LIKE KO-PICKS 2 2. Y

KU-UK-KUK

4 h i i k 1 m

36 PUDDLE woo- ANK- UP UVULAR KE-AW 0-OT : 2. oo-woo Y I

1, +I kr IIIt II‘

1 2 3

SECONDS FIGURE 2. Vocalizations given by Common Ravens in Virginia: a-the awk; b-clucks; c-the /cow;d and e-bell- like sounds;f-the ku-uk-kuk; g-the ko-pick; h-the ank-up; i-the woo-oo-woo;j-descending uvular sound; k- the o-ot; l-the puddle; m-the ke-aw.

when nestingpairs were disturbedat their nests. when examining young, and an adult dived at The clucks were usually given by flying or me, flew over me, or perched in a tree nearby. perching birds after some time had elapsed Context-2. The male raven of a nestingpair (10-l 5 min.) during my nest visits. gave the call once when attacking a strange Context-2. On 12 occasions, ravens gave raven that flew within 50 m of its cliff nest (five cluckswhen displaced from what appeared to cases).The call was given immediately before be a favored roost position. the male raven’s physical contact with the in- truder. Ravens also gave kows as they chased THE KO W (FIG. 2c) other ravens out of the roost (three cases). The kow, which resembled the high pitched Context-3. I heard the kow during an ag- honk of a Canada Goose (Branta canadensis), onistic encounter between two male ravens. was the loudest call I heard. The call has many Pairs A and B were standing to the side of a harmonics, which range up to 7,000 Hz. Al- landfill trench when pair B walked over to though I observedravens give the call 23 times, within 2 m of pair A. The two males were the I tape-recorded it only once. closestbirds, with the femalespositioned about Context--I. I heard this call 18 times at nests 0.5 m behind their mates. All four ravens dis- 384 RICHARD N. CONNER played tufts of feathers on either side of the THE KO-PICK (FIG. 2g) tops of their heads as well as their throat and The ko-pickresembled the sound of a coffee leg feathers. The pairs faced each other silently percolator; however, its tonal quality was sim- for about 1 min, after which pair B flew into ilar to the bell-like sounds(Fig. 2d, e). Ravens the trench and beganto feed. Pair A then began always gave the ko-pick twice in succession courtship activities, after which male A flew (Fig. 2g). Two frequencies (700 and 1,100 Hz) into the trench, displayed his throat, leg, and occasionallycomposed the first element of each all his head feathers, and walked toward male call. B. Male B then displayed the same feathers Context- 1. I heard the ko-pick 16 times. and hopped toward male A. Both ravens faced Paired ravens gave this call while flying (12 each other for 10 s with their heads held high occasions)and while perched in the roost (four and bills pointed slightly downward. Both cases).I noted no particular behavior associ- males began hopping off the ground slightly, ated with the call. as if to gain an advantage over each other. The apparently more dominant male A then at- THE ANK- UP (FIG. 2h) tacked male B, jumped up in the air 1.5 m, gave a kow, and landed on male B. Male A The ank-upresembled the squeakingof an old tried to clutch male B with its feet while beat- fashioned pump handle. The call was similar ing with its wings and thrusting with its bill. to the Blue Jay’s (Cyanocittacristata) pump Male B broke loose and rapidly flew off un- handleor squeakygate call (Cohen 1977), but pursued by male A. Female B followed male was much lower in pitch. Ravens usually re- B as he flew off. peated the call twice. I made concurrent behavioral observations on all of the eight calls recorded. THE BELL-LIKE SOUND (FIGS. 2d and e) Context- 1. One of a pair of flying ravens (three This call was not loud, but I could hear it from different pairs) gave this call at nest sites(eight a distance of more than 1 km under good con- occasions). On two occasions, its mate re- ditions. The sound resembled that emitted by sponded with the cawlupcall (Fig. li). In four a bell or xylophone that had been struck while instances,a raven gave the ank-upcall in re- being held to prevent continued ringing. Ra- sponseto a cawlupcall from its mate. vens also gave the call softly so that it resembled soft hoots of a Great Horned Owl (Bubo INFREQUENT VOCALIZATIONS (FIG. 2i, j, k, 1,and m) virginianus).I recorded 10 of the 27 calls I heard. I heard many vocalizations only once or rarely. Context- 1. Male and female ravens gave bell- I was able to record some of them to document like sounds during aerial courtship (20 in- their existence and illustrate the variety of ra- stances)and courtship on the ground and in ven vocal behavior. An unseen raven gave a trees (six cases).Perched ravens displayed all soft woo-oo-woo at the roost (Fig. 2i). A single head, throat, and leg feathers in addition to pair of ravens gave the following calls while spreadingtheir rectrices when giving the call. flying when I disturbed them at their nest: a Bell-like sounds were heard most frequently descendinguvular sound (Fig. 2j), a call sound- during the breeding season. ing like o-ot(Fig. 2k), and a call soundingmuch Context-2. I heard the call during what ap- like puddle,puddle, puddle, puddle (Fig. 21). A peared to be an agonistic interaction between rattle (Fig. 1h) was the responsewhen one of two male ravens. Both males had all head, the pair gave a ke-aw(Fig. 2m) call four times. throat, breast, and leg feathers displayed and gave the bell call before strutting parallel to DISCUSSION each other. Goodwin (1976) described Common Ravens as “very loquacious.” Common Ravens in THE KU- UK-KUK (FIG. 2f) Virginia fit this characterization and regularly The ku-uk-kukcall was a harsh, staccatocou- gave a variety of calls. Fundamental frequen- plet or triplet with frequenciesranging between cies of most calls ranged from 250 to 2,300 Hz 600 and 4,000 Hz. It resembled the cluck(Fig. (Table 1, Brown 1974), which are well suited 2b) slightly and also had a sputter-like quality. for long distance communication (Wiley and I recorded only one of the 18 calls I heard. Richards 1982). I recorded sufficient numbers Context- 1. The ku-uk-kukcall was given by and social contexts of some calls to permit a raven as it chasedanother raven at the roost speculation on their social interpretation (Ta- (18 occasions).Usually, the pursuingraven was ble 2). Many of these calls are used by ravens as close as 2 m to the pursued raven when in similar contextsin other areasof their range. giving the call. The caw (Fig. la) was used in a variety of COMMON RAVEN VOCALIZATIONS 385 contexts and seemedto convey general excite- time. Morton (1982) suggestedthat soundsof ment, whether the stimulus was from a poten- this structure are used by fearful or appeasing tial predator, daily activities, “play,” or ago- individuals. nistic interactions of other ravens. The caw is European ravens also gave rattle calls (Fig. probably the most frequently described call in lh). Gwinner (1964) described a gro call that other areasaround the world. My observations intimate ravens gave when reunited and dur- on social context support and expand on what ing pair feeding in captivity. Coombs (1978) Gwinner (1964) Brown (1974), and others noted that Gwinner’s (1964) ravens gave a found. Brown (1974) recorded a sonagraphi- softer version of the gro call, the “Gauzlaute,” tally similar call in Alaska and thought it to when mutual preeningwas done roughly. Emeis function as a “distress” call. Gothe (in Gwin- (1926) also heard a deep rattle call, followed ner 1964) and Gwinner (1964) describeda rapp by a bell-like call, from a wild pair of ravens or krapp that was given by flying German ra- in Germany. The rattle calls that I heard were vens in the wild and in captivity. Wilmore given mainly by pairs of ravens during the (1977) also described a krok-krok-krok given breeding seasonand often were associatedwith by flying ravens. Russian ravens (C. c. corax) bell-like sounds.Brown (1974) did not report give a croaking, described as kruk, kruk, kruk rattle calls in Alaska. I suspectthat rattle calls (Dement’ev et al. 1954). Tyrrell (1945) de- serve as a part of courtship and aid in strength- scribeda hoarse,gutteral, rolling cr-r-r-r-truck ening pair bonds. I observed ravens using a that may be the same as the caw I heard. Some gapingor choking action as they gave the rattle of the variation (frequency, Hz) in the caw may call. This posture may be necessaryto produce relate to the age and sex of ravens. I noted, as the mechanical clicks that compose the rattle. did Harlow (1922) that caws of females were Lorenz (1940), however, also observed a chok- higher in pitch than those in males. Much of ing action, but with what may be a different the within-call variation in frequency, how- call: Krrooa (Goodwin 1976). ever, may also relate to unidentified social Only North American ravens have been re- communication. ported to give the cawlup call (Fig. li). Brown European and Alaskan ravens also give (1974) describeda sonagraphicallysimilar call growl-like calls. These vocalizations of Virgin- as Kowah, but could attach little behavioral ia ravens (Figs. 1b, c, and d) resemble the typ- significance to it. Although Griffin and Mc- ical enemy call, “Gewbhnliche Feindruff,” and Callum (195 1) heard a tch-reepwhen one pair loud enemy call, “Laute Feindruf,” recorded of ravens attacked another pair in England, I by Gwinner (1964). He thought the calls to be doubt that they heard the call I described as a defensive reaction to a predator stimulus. cawlup. I never heard the cawlup given during Brown (1974) also heard a sonagraphically aggression or attacks in Virginia. Gwinner similar call (“antagonistic Kaaa”) given by (1964) did not hear a similar call from captive subordinate ravens when threatened by more German ravens. I have no direct evidence on dominantbirdsinAlaska.Morton(1977,1982) the socialfunction of the cawlup call, but spec- predicted that soundsused by aggressivebirds ulate that it serves to convey location. should be low and relatively constant in fre- The use of staccato caws (Fig. lj) by ravens quency (Hz). My observations on growl-like in alert situations has previously been de- calls, as well as Gwinner’s (1964) and Brown’s scribed in North America (Tyrrell 1945, Dorn (1974), support Morton’s prediction. 1972, Brown 1974, Conner et al. 1975). Gwin- Whines (Figs. le, f, and g) were also given ner’s ravens in Germany may not have given by ravens in Alaska and Europe. In Virginia, staccato caws becauseof the restraints of cap- submissive ravens gave whines during con- tivity. Emeis (1926), however, heard fiight- flicts with other ravens. Brown (1974) record- ened, wild ravens give a short, loud rub or ra. ed a sonagraphicallysimilar call that he thought I played staccatocaws (Fig. lj) back to ravens was given only by young ravens as a defensive on three occasionsat nest sites. On each oc- call. Gwinner (1964) reported a sonagraphi- casion, the birds became excited and flew tally similar ruh call given by young and adult around, scanningthe ground and sky. ravens that he thought served in part as a sub- Clucking (Fig. 2b) may have indicated dis- missive call. Gwinner also recorded a “Win- tressor thwarting becauseravens gave the call sellaute” (whine or whimper) that young ra- when they were unable to drive me away from vens gave when preened by their parents. a nest. Dorn (1972) also recorded a cluck call, Whines may serve as an appeasement sound but attached no social significance to it. Al- to avoid further hostile interaction with though Gwinner (1964) heard “glucken” stronger, more dominant birds. Relative to (clucking) from captive ravens, his sonagram growl-like calls,whines are higher in frequency of the call resembles that of the bell-like call (Hz) and tend to decrease in frequency over (Fig. 2e) in frequency (Hz) and structure. 386 RICHARD N. CONNER

The kow (Fig. 2c) served as an aggressive described in North America. Harlow (1922) call and, in many instances,as an actual attack mentioned a rare call that soundedlike ge-lick- call in North America and Germany. When ge-lee. Brown (1974) described a Ku1 pick or teased, a captive raven in Virginia also gave Ko puck that he thought to be a variation of the kow while in its cage (Dwight R. Cham- the bell-like call (Figs. 2d and e). He thought berlain, pers. comm.). Gwinner’s (1964) cap- the last part of the call was produced by a bill tive ravens gave a krack that is probably the snap. This was not the case in the calls I re- same as the kow when attacking and during corded. Jollie (1976) heard tPuck’ calls from intense conflict. Wilmore (1977) mentioned a North American ravens during their “greeting konkgiven by ravens (location not mentioned) and intimidation” displays. He noted that Lo- during aggression with predators. In Wyo- renz (1940) and Gwinner (1964) did not de- ming, Dorn (1972) recorded a high pitch ky scribe this call. Although the ko-pick was a that appears similar to the kow, but made no pair-associatedcall, Brown (1974) and I could mention of its social context. Brown (1974) not identify its specific social function. also recorded a sonagraphically similar “ju- I could not discern the social significanceof venile Kaah” in Alaska, but it was not an adult the remaining seven calls (Fig. 2a, h, i, j, k, 1, call. The calls I heard were given by what al- and m), two of which are widely used by ra- ways seemed to be adult birds. Dement’ev et vens. Brown (1974) recorded a call similar to al. (1954) reported a kaarr, kaarr . . . emitted the puddle call (Fig. 21);he, too, could not dis- by desert ravens (C. corax ruficollis) when at- cern a social function. Emeis (1926) heard a tacking, but this call was probably a caw (Fig. kyou, kyou that closely resembles the ke-aw la). (Fig. 2m). He also heard a “rattle” in con- Ravens in North America and Europe give junction with the call from a pair of wild ra- bell-like sounds(Fig. 2d and e) mostly during vens. courtship. I suspect that these calls serve to Most corvids, excepting the Jackdaw (Cor- strengthenpair bonds and, perhaps, help syn- vus monedula) and Cuban Crow (C. nasicus), chronize partnersin the nestingcycle. Gwinner may have a somewhat similar repertoire of (1964) heard a captive female give a bell-like calls (Jollie 1976). Several North American call as a response to a male during a bowing corvids have calls that resemblethose of Com- ceremony. He believed the call to be an imi- mon Ravens. White-necked Ravens (C. albi- tation of a bell. Ross (1925) and Brown (1974) collis) give Kre and “growling” soundsthat are heard a call that sounded like a xylophone. similar in sound and function to the Common Brown observed females give the call from a Raven’s caw and growl-like sounds, respec- slightly crouched submissive posture in the tively (Jollie 1976). The similarity of thesecalls presenceof a courting male and during strut- reflects the close affinity of the two species ting ceremonies as the female followed a strut- (Goodwin 1976). Although higher in pitch, the ting male around. On one occasion, the call American Crow’s “scolding” and “dispersal was given just before an unsuccessfulattempt calls” (Chamberlain and Cornwell 197 1, Jollie at mounting. Gilbert (1927) described the call 1976) are similar in sound and function to in Englandas “a triple tot- tot- tot” and thought Common Raven cawx and staccato caws, re- it could be an “invitation note.” Emeis (1926) spectively. American Crows give a raucous heard a bell-like call from wild ravens in Ger- “assembly call” when near predators; the call many that he describedas a kjou, khou. Gothe apparently servesto assemblea group of crows (in Gwinner 1964) heard a klong, djong or to drive predators away from nesting,roosting, krong given during aerial courtship. Common or feeding areas (Chamberlain and Cornwell Ravens in Tibet also gave bell-like sounds 197 1). Although mobbing by non-breeding (Wilmore 1977). The bell-like call may serve flocks of ravens occurred, I never detected a a different function when given among males, specific assembly call. becauseboth Gwinner (1964) and I heard the Although much higherin pitch, the Blue Jay’s call during what appeared to be agonistic be- jay call resembles Common Raven caws and havior between males. is also given during excitement (Cohen 1977). The ku-uk-kuk call (Fig. 2f) resembled the Like ravens, thesejays also give a “rattle” and cluck (Fig. 2b), but was used as a threat during a “bell call,” mainly during the breeding sea- aerial chases.Brown (1974) describeda Kukuk son (Cohen 1977). The Blue Jay’s “squeaky given by ravens under analogous circum- gate” call given during the prenesting season stancesin Alaska. Gwinner (1964) did not re- (Cohen 1977) resemblesthe Common Raven’s port such a call from ravens in Germany, pos- ank-up call. Florida Scrub Jays (Aphelocoma sibly becauseof the limited ability of his captive coerulescens)give a mechanical,clicking sound ravens to chaseeither each other or intruding that may also resembleCommon Raven rattles strangeravens. (Woolfenden and Fitzpatrick 1984). Ko-pick calls (Fig. 2g) have previously been Imitation of other speciesand non-animate COMMON RAVEN VOCALIZATIONS 387

soundsis widespread in the Corvidae (Good- lected vocalizations of the Common Crow. Auk 86: win 1976). Gwinner (1964) suspectedthat some 613-634. soundshis captive ravens made were imitated. COHEN,S. M. 1977. Blue Jay vocal behavior. Ph.D. diss., Univ. of Michigan, Ann Arbor. Common Ravens can imitate the caw of the CONNER,R. N., I. D. PRATHER,AND C. S. ADIUSSON.1975. American Crow (Jollie 1976). Coombs (1978) Common Raven and starling reliance on sentinel noted that ravens modify innate and learned Common Crows. Condor 77:517. calls and use these sounds to recognize indi- COOMBES,R. A. H. 1948. The flocking of the raven. Br. Birds 41:290-295. vidual ravens. He suggestedthat a raven can COOMBS,F. 1978. The crows. B. T. Batsford, London. use “its partner’s special sounds” to call its CUSHIN~,J. E. 1941. Winter behavior of ravens at To- mate and cause it to come immediately. males Bav. California. Condor 43: 103-107. I believe that many of the calls I recorded DEMENT’EV,G. ‘P., N. A. GLADKOV,A. M. SUDILOVSKAYA, E. P. SPANGENBERG,L. V. BOEHME,I. B. VOL- are innate, based on their similarity to vocal- CHANETSKII,M. A. VOINSTVENSKII,N. N. GOR- izations of other corvids and Common Ravens CHAKOVSKAYA,M. N. KORELOV,AND A. K. Rus- elsewherein the world. Although vocalizations TAMOV. 1954: Birds of the Soviet Union. Vol. 5. learned in one environment can spread from Enelish Trans. 1970. Israel Proaram for Scientific one individual to another (Slater 1983), trans- Tr&lations, Jerusalem. - DORN,J. L. 1972. The Common Raven in JacksonHole, fer of such soundswould be inhibited by iso- Wyoming. M.Sc. thesis,Univ. of Wyoming, Laramie. lation. Ravens in Virginia are disjunct from EMEIS,W. 1926. Beobachtungenan Kolkraben Horsten the rest of the North American population and in Schleswig-Holstein.J. Omithol. 74:5 16-621. certainly remote from those in Germany. FENNEMAN,N. M. 1938. Physiographyof easternUnited Gwinner’s (1964) captiveswere all hand-reared States. McGraw-Hill, New York. GILBERT,H. A. 1927. Peculiar note of Raven. Br. Birds and almost completely isolated from wild ra- 20:229. vens. Thus, identical calls given by Gwinner’s GOODWIN,D. 1976. Crows ofthe world. British Museum birds and ravens in Virginia (cuw, growl-like, (Natural History), London. whines, rattle, kow, bell-like) are probably in- GRIFL~N,D. M., AND D. L. MCCALLUM. 1951. Unusual call of raven. Br. Birds 44: 174. nate. GWINNER,E. 1964. Untersuchungenttber das Ausdrucks Many other raven calls may be learned and und Sozialverhaltendes Kolkraben (Corvm corax cor- passedon to subsequentgenerations. Gwinner ax L.). Z. Tierpsychol. 2 11657-748. (1964), Brown (1974), and Dorn (1972) all re- HARLOW,R. C. 1922. The breedinghabits ofthe northern ported calls that I did not hear in Virginia. raven in Pennsylvania. Auk 391399-410. HOOPER,R. G., H. S. CRAWFORD,D. R. CHAMBERLAIN, Ravens in Virginia, however, had more calls AND R. F. HARLOW. 1975. Nesting density of Com- in common with other North American ravens mon Ravens in the Ridge-Valley Region of Virginia. (about 10 calls) than with European ravens Am. Birds 29:931-935. (seven calls), suggestingthat distance and geo- JOLLIE,M. 1976. Species interrelationships of three Corvids. Biologist 3:89-l 11. graphic barriers (water) may influence the ex- KNIGHT, R. L., AND M. W. CALL. 1980. The Common change of learned calls. Raven. USDI Bureauof Land Management Technical Note 344, Denver, CO. ACKNOWLEDGMENTS LORENZ.K. 1940. Die Paarbilduna beim Kolkraben. Z. Tierpsychol. 31278-292. - The Departments of Biology, and Fisheries and Wildlife LUCID, V. J., AND R. N. CONNER. 1974. A communal Sciences,Virginia Polytechnic Institute and State Uni- Common Raven roost in Virginia. Wilson Bull. 86: versity, provided partial support for this study. I thank 82-83. the GAL-TEX Hotel Corporation for permission to study MORTON,E. S. 1977. On the occurrenceand significance ravens roosting behind the Mountain Lake Hotel. I thank of motivation-structuralrules in somebird and mam- I. D. Prather, V. J. Lucid, R. G. Hooper, and D. R. Cham- ma1sounds. Am. Nat. 111:855-869. berlain for their contributions to certain aspects of the data-collectionphase of the study. I also thank S. Conant, MORTON,E. S. 1982. Grading, discreteness,redundancy, C. H. Trost, T. A. Jenssen, D. R. Chamberlain, J. W. and motivation-structured rules, p. 183-212. In D. Hardy, and C. S. Adkisson for reviewing the manuscript E. Kroodsma and E. H. Miller [eds.], Acoustic communication in birds. Vol. 1. Academic Press, New and making many excellent comments and suggestions. York. MYLNE, C. K. 1961. Large flocks of ravens at food. Br. LITERATURE CITED Birds 54:206-207. AMERICANORNITHOLOGISTS UNION.’ 1983. Check-list of Ross, R. C. 1925. Field notes on the raven. Condor 27: North American birds. 6th ed. American Omithol- 172. ogists’ Union, Washington, DC. SLATER,P. J. B. 1983. Bird song learning: theme and BAILEY,R. G. 1978. Description of the ecoregionsof the variations, p. 475-499. In A. H. Brush and G. A. United States. USDA Forest Service. Intermountain Clark [eds.], Perspectivesin ornithology. Cambridge Regions, Ogden, UT. Univ. Press, Cambridge. BENT,A. C. 1946. Life histories of North American jays, TYRRELL,W. B. 1945. A study of the northern raven. crows, and titmice. U.S. Natl. Mus. Bull. 191. _ Auk 62:1-7. BROWN,R. N. 1974. Aspects of vocal behavior of the WILEY,R. H., ANDD. G. RICHARDS. 1982. Adaptations raven (Corvuscorm) in interior Alaska. M.Sc. thesis, for acoustic communication in birds: sound trans- Univ. of Alaska, Fairbanks. mission and signal detection, p. 131-181. In D. E. BRUEMMER,F. 1984. Ravens, smartestbirds in the world. Kroodsma and E. H. Miller [eds.], Acoustic com- Int. Wildl. 14(5):33-35. munication in birds. Vol. 1. Academic Press, New CHAMBERLAIN,D. R., AND G. W. CORNWELL.1971. Se- York. 388 RICHARD N. CONNER

WILLETT,G. 1941. Variation in North American ravens. Department ofBiology, Virginia PolytechnicInstitute and Auk 581246-249. State University,Blacksburg, Virginia 24061. Presentad- WILMORE,S. B. 1977. Crows, jays, ravens and their rel- dress:Southern Forest Experiment, Station, USDA Forest atives. T. F. H. Publications, Surrey, Great Britain. Service,Box 7600 SFA, Nacogdoches,Texas 75962. Re- WOOLFENDEN,G. E., ANDJ. W. FITZPATRICK.1984. The ceived 27 August 1984. Final acceptance18 March 1985. Florida Scrub Jay. Monogr. Popul. Biol. 20.

The Condor 87:388 0 TheCooper Ornithological Society 1985

RECENT PUBLICATIONS

The life and lettersof Alexander Wilson.-Edited by Clark Johann Friedrich von Brandt. Icones Avium Rossico- Hunter. 1983. American Philosophical Society, Philadel- AmericanarumTab&e VII, Ineditae/with commentson phia. 456 p. $50.00. Alexander Wilson was born in Scot- birds, expeditions and people involved.-Bemt Lsppen- land in 1766 and spent his early adult years there as a thin. 1984. Scandinavian fine editions, Copenhagen. 70 weaver,peddler, reformer, and poet. He came to the United p. 385 Danish kroner ($34.75). Source:Scandinavian fine States in 1794 and turned to school teaching, which led editions, P.O. Box 1019, DK- 1007, CopenhagenK, Den- to his acquaintanceand friendship with the botanist, Wil- mark. Brandt (1802-l 879) was a German physician who liam Bartram. This associationaroused his interestin birds, made his career as director of the zoological museum at ultimately his aim to publish the most complete illustrated the Academy of Sciencesin St. Petersburg.Based on spec- account of the birds of America that had yet been at- imens collected by others, he published many papers, in- tempted. The enterpriselasted but ten years,until his death cludinga descriptionof the cormorant specieswhich bears in 18 13, but it sufficedto establishWilson ’s reputation as his name. He worked on, but never completed, a large the “Father of American Ornithology.” The present book work on the birds of the RussianNorth Pacific possessions, offers first a good, relatively brief biography of the man including the Russianterritories in America (now Alaska). and then 150 of his letters, many of them newly published Apparently made for that opus were seven unique, hand- or published complete for the first time. They contain a colored lithographicplates, drawn about 1835 by W. Pape. wealth of fascinating observations about his travels and They are here publishedfor the first time, reproducedfrom the progressof his Ornithology.Several additional docu- a set in the University Library, Copenhagen.bppenthin ments are given in the appendices.The volume itself has provides valuable backgroundon Russian American set- been beautifully designed and printed, a rare treat in an tlements and expeditions before 1835, of importance to era of computerizedphoto-typesetting. It is illustratedwith ornithological studies. He then discusses,for each of the photographs,maps, wood engravingsby Thomas Bewick, 44 speciesof birds, the history of its taxonomy and of the and selected reproductions of Wilson’s plates- together specimen depicted. The plates themselves appear to be with Audubon’s plates of the same birds. The book adds accuratefacsimiles in size, color, and detail. This schol- important new details to our picture of this pioneer or- arly, well-produced volume makes a signal contribution nithologist. to the ornithological history of the North Pacific and Ber- ing Sea. List of references,index, map.