Wilson Bull., 111(4), 1999, pp. 488-493 NESTING BEHAVIOR OF THE LILAC-CROWNED PARROT KATHERINE RENTON' AND ALEJANDRO SALINAS-MELGOZA^ ^ — ABSTRACT. Nesting behavior of the Lilac-crowned Parrot (Amazona finschi) was observed over a three year period at 24 nests in the tropical dry forest of the Chamela-Cuixmala Biosphere Reserve, western Mexico. Nest site characteristics and the pattern of parental care throughout the nesting cycle are described for this mainland Amazon parrot and compared with that reported for other Amazon parrot species. Nest sites were located in natural cavities of large mature trees characteristic of semi-deciduous forest. Nest sites were similar to one another in tree species, tree size, cavity height, and entrance width, indicating that Lilac-crowned Parrots may select nest sites based on these characteristics. Unlike most parrot species. Lilac-crowned Parrots showed low nest site reuse and high synchrony of nest initiation. Throughout the nesting cycle, females and nestlings were fed only twice a day on average. Nest attendance during feeding visits was short. The infrequent feeding visits and short nest attendance exhibited by Lilac-crowned Parrots corresponds with that found for other main- land Amazon parrots in northeastern Mexico, but contrasts with the multiple feedings and longer nest attendance observed for island Amazon species. The distinct aspects of Lilac-crowned Parrot nesting behavior may be related to predation rate and food resource availability during the extreme dry season. Received 10 March 1999, accepted 15 July 1999. Most studies on the ecology of Neotropical demic to western Mexico and has a restricted Amazon parrots have been conducted on spe- distribution from southeastern Sonora to Oa- cies inhabiting the Caribbean Islands (Snyder xaca (Forshaw 1989). There have been no et al. 1987, Gnam 1991, Gnam and Rockwell studies on the ecology of the Lilac-crowned 1991, Wilson et al. 1995). A comparative Parrot, and little is known of its breeding bi- study of three species of mainland Amazon ology (Forshaw 1989). Anecdotal reports parrot in north-eastern Mexico found distinct from captive breeding give an incubation pe- differences compared with island species in riod of 28 days, with the young chick leaving some aspects of reproductive behavior and the nest after 60 days (Mann and Mann 1978). productivity (Enkerlin-Hoeflich 1995). Fe- In this paper we present observations on the males and nestlings of three mainland Ama- nest site requirements and nesting behavior of zon parrot species were fed only twice a day the Lilac-crowned Parrot in the wild, and (Enkerlin-Hoeflich 1995), in comparison with compare them to observations for other island the multiple feedings observed for Caribbean and mainland Amazon parrots. Amazons (Snyder et al. 1987, Gnam 1991, STUDY AREA AND METHODS Wilson et al. 1995) and other Neotropical par- rots (Fanning 1991, Waltman and Beissinger Studies on the breeding biology of the Lilac- 1992). Additional data on mainland Amazon crowned Parrot were conducted at the 13,142 ha Cha- parrots are needed to determine whether con- mela-CuiWxmala Biosphere Reserve (19° 22' N, 104° 56' to 19° 35' N, 105° 03' W) on the Pacific clusions from studies on island species are ap- plicable to mainland species. The Amazon ccolaismtateofexMheixbiictoin.gTahmearstkueddysseiatseonhaalsitay idnrypretrcoippiictaal- parrot species of Mexico are particularly suit- tion, with 80% of the 748 mm average annual rainfall ed for comparison with the Amazona species occurring June to November, and a prolonged drought of the Greater Antilles in the Caribbean be- from mid-February to late May (Bullock 1986). The cause of their close evolutionary relationship reserve has a hilly topography varying in elevation (Snyder et al. 1987, Forshaw 1989). The Li- from 20-520 m above sea level. The dominant veg- etation type on the slopes is tropical dry deciduous lac-crowned Parrot (Amazona finschi) is en- forest, with semi-deciduous forest in the larger drain- ages and more humid valleys (Lott et al. 1987, Lott ' Durrell Institute of Con.servation & Ecology, The 1993). Monospecific forests of Celaenodendron mex- Univ. of Kent at Canterbury, Kent, CT2 7NJ, U.K. icaniun also occur as discontinuous patches within ^ Fundacion Ecologica de Cuixmala, Apartado Post- the tropical deciduous forest mosaic (Martijena and al 161 .San Patricio-Melaque, Jalisco, CP 48980, Mex- Bullock 1994). , Observations on the nesting behavior of Lilac- ico. ’ Corresponding author; crowned Parrots were conducted from January to June E-mail; [email protected] in 1996-1998. Nest searches were earned out in Feb- 488 Renum and Salinas-Melf>oza • LILAC-CROWNED PARROT NESTING BEHAVIOR 489 TABLE 1. Cavity dimensions for 26 Lilac-crowned Parrot nests. Coefficient of variation Nest character Mean Standard deviation Range (s/m) X 100 Tree diameter at brea.st height (cm) 43.1 1 1.4 27.7-66.3 26.3% Cavity height from ground (m) 9.7 1.7 7.4-14.7 17.8% Entrance width (cm) 10.0 2.3 6.4-14.0 22.5% Entrance length (cm) 21.0 16.0 7.5-71.6 76.2% Internal diameter (cm) 19.9 6.8 10.5-35.0 34.3% Cavity depth (cm) 66.2 51.7 24-260 78.1% Circumference at entrance (cm) 86.7 30.0 26-135 34.5% Neare.st active nest (m) 948.9 707.7 25-2419 74.6% ruary during the nest prospecting and early incubation RESULTS phases of the parrot breeding cycle. No additional — A nests were located later in the nesting cycle because Nest site characteristics. total of 29 the behavior of breeding pairs made detection of nest nest sites were located in 1995-1998, all of sites difficult. A cavity was considered a potential nest which occurred in natural cavities. Nest cav- site if one or both of the adult panots were observed ities were located in live trees of Celaenoden- entering it. The cavity was considered an active nest dron rnexicanum, local name Guayabillo site if one of the adult parrots remained within the = (51.7%, n 15), and Astronium graveolens, ctaevrimtiynefdorflroonmgetrhethfarneq3u0enmciyn.ofNecsatvistiyteorcecuuspeawnacys dbee-- local name Culebro (31.0%, n = 9). Of the tween years. remaining 5 cavities, 2 were located in a Ta- Access to nest cavities was achieved using both sin- bebua species, 1 was located in a dead tree, gle-rope ascending (Perry 1978, Perry and Williams and 2 were located in unidentified trees. Nest 1981) and a tree bole climbing technique (Donahue site reuse was low, with only 3 (10.3%) of the and Wood 1995). Nesting requirements of the Lilac- 29 nests sites located between 1995 and 1998 crowned Parrot were determined by measurement of being used by nesting pairs over more than nest cavity dimensions: tree species, diameter at breast height (DBH) of the tree, height above ground of the one breeding season. One cavity was used in entrance, width and length of entrance, cavity depth, three of the four years; 1995, 1997, and 1998. internal diameter, and circumference of the tree at en- Two other cavities were reused once after a trance (Saunders 1979, Saunders et al. 1982). The lo- vacancy of one year. cation of each nest site and where possible the tree Mean cavity dimensions for 26 active nest used by the nesting pair for the transfer of food from sites are presented in Table 1; three cavities the male to the female were obtained using a geo- could not be accessed for safety reasons. The graphic positioning system. The coefficient of varia- tion was determined for the mean cavity dimensions cavity dimensions with the least variation to evaluate the variability of characteristics between were height of entrance from the ground and nest sites. width of entrance. Diameter of tree at breast Behavior of breeding pairs was determined by ob- height was relatively consistent between nest servations of parrot nests from covered blinds using sites and reflects the fact that parrot nests were 10 X 40 binoculars. Continuous dawn to dusk obser- located in large, mature trees characteristic of vations were conducted on 30 man-days (360 hours) at 8 nests. No activity was observed at nests during semi-deciduous forest. The greatest variability mid-day; therefore additional observations were re- was found in depth of cavity and length of stricted to the first four hours after sunrise and the last entrance. — three hours prior to sunset giving an additional 299 Egg-laying and incubation Timing of . hours of observation at 16 nests. Parental care and in- egg-laying was highly synchronized between vestment was evaluated from the number of feeding nests with most pairs commencing incubation visits to the nest, arrival time, duration of feeding visit, within 14 days of the first nest being initiat- time spent in the nest cavity, and time spent in the nest m ed. Mean nest initiation date was 6 February area (defined as within 100 of the nest). Descriptive statistics are presented with means, ranges, and stan- ± 4.6 (SD) days in 1996 (range: 30 January- — dard deviations. 13 February, n 8), and 15 February ±5.3 490 THE WILSON BULLETIN • Vol. Ill, No. 4, December 1999 days in 1997 (range: 10-23 February, n = Nesting pairs became more secretive around 6 nests, arriving and departing silently. Pairs ). Nest attendance by the female was high used low, almost inaudible vocalizations when during incubation, with the female leaving the in the nest area. Pairs were cautious about ap- nest only once in the morning and once in the proaching the actual nest, and would not do afternoon to be fed by the male. The female so if they detected an observer or another dis- spent a mean of 39.4 ± 26.5 min per day out turbance. The nesting pair made an average of the nest over both morning and afternoon 2.6 ± 0.9 visits per day (range: 2-4 visits, n feeding sessions (range: 15-95 min per day, n = 25) to feed the nestlings. Average duration = 20). Conversely, the male was rarely ob- of feeding visits during the nestling phase was served entering the nest or perching on the 72.3 ± 42.3 min (range: 12-171 min, n = 31). nest rim. Daily activity periods were consis- However, the nesting pair spent the majority tent between nests with the male making an of this time perched in trees around the nest average 2.1 ± 0.3 nest visits per day (range area. Attendance at the actual nest cavity was 2-3 visits, n — 35) to feed the female. Mean short, lasting an average of 10.6 ± 11.2 min arrival times for the morning and afternoon [range: 1.0-27.2 min, n = 30 (total time either activity periods were respectively 08:24 EST adult in nest cavity or at entrance)], with a ± 46 min (range: 06:07-10:08, n — 45) and mean of 5.4 ± 4.5 min per visit (range: 0-17 — 18:14 EST ± 26 min (range: 17:15—19:03, n min, n 30) spent within the nest cavity, and = 40). Each feeding visit by a male lasted an a mean of 6.0 ± 12 min (range: 0-20.6 min, average of 33.9 ± 25.6 min (range: 5-113 n = 30) perched at the nest rim. Each adult min, n = 80). spent a mean of only 4.0 ± 3.5 min (range: = The male usually vocalized loudly on his 0.42-17 min, n 41) inside the nest cavity approach to the nest area and perched in a tree per feeding visit. This was sufficient time to adjacent to the nest cavity making low contact feed the young; however, there was no indi- vocalizations until the female emerged. The cation that parent birds spent any other time nesting pair gave a characteristic take-off in the nest with the young except when feed- squawk, or bugle, as the female flew from the ing them. nest cavity to join the male. Food transfer Prior to fledging, nestlings began to climb from the male to the female took place in a to the nest entrance, and were fed at the nest regular perch tree located an average 423 ± rim. During this stage, nesting pairs spent 228 m (range: 149-983 m, n = 11) from the more time perched near the nest entrance nest cavity. The food transfer session was the making low contact vocalizations to the only time during the incubation phase when young. Mean age at fledging was 63.7 ± 3.2 both adults were away from the nest area and days (range: 56-68 days, n = 22). Nestlings was short in duration (average 11.5 ± 10.4 fledged asynchronously, and all nests fledged min, range: 2-48 —min, n = 78). young within a 2-3 week period. All nestlings Parental care. Eggs hatched asynchro- fledged within 12 days in 1996 (mean fledge nously, and females continued to brood nest- date = 10 May ± 4.34 days, range: 6-18 May, lings during the day until the oldest nestling « = 8), 17 days in 1997 (mean fledge date = = was 19.6 ± 2.7 days old (range: 15-23 days, 18 May ± 6.68 days, range: 11-28 May, n = n = 9). Females ceased roosting in nests over- 7), and 13 days in 1998 (mean fledge date = night when the youngest chick was in its third 8 May ± 5.16 days, range: 2-15 May, n week. During this early nestling phase, the 7). male continued to feed the female twice a day DISCUSSION and was occasionally observed to enter the nest for a mean 1.7 ± 2.8 min (range: 0—8 The low variability between nest sites in min, n — 9) per feeding visit. Later in the tree species, size, cavity height, and entrance nesting cycle when the chicks were larger, width suggests that Lilac-crowned Parrots both parents entered the nest to feed the may select nest sites based on these charac- young. teristics. Predation rates decrease with increas- The behavior of nesting pairs altered once ing height of nest sites from the ground (Nils- the female began to forage with the male. son 1984, Wilcove 1985), while the increased Renton and Salinas-Mel}>oza • LILAC-CROWNED PARROT NESTING BEHAVIOR 491 size of nest entrance required by large birds clines (Renton 1998). Delaying nest initiation may pose greater risks from predation, leading may result in breeding pairs having to conduct to specific requirements for entrance dimen- energetically demanding activities of raising sions (Christman and Dhondt 1997). Amazon young during this environmentally difficult parrots in northeastern Mexico appear to se- period. lect cavities based on tree species, cavity The infrequent feeding visits to the nest by height, and entrance length (Enkerlin-Hoeflich breeding pairs of the Lilac-crowned Parrot 1995). Australian cockatoos also demonstrate contrasts with the multiple daily feedings not- species specific requirements related to body ed for island Amazona species (Snyder et al. size for entrance dimensions and internal di- 1987, Gnam 1991) and other Neotropical par- ameter of nest hollows (Saunders et al. 1982). rots (Lanning and Shiflett 1983; Lanning Enkerlin-Hoeflich (1995) suggested that vari- 1991; Waltman and Beissinger 1992; K.R., ability in several cavity characteristics com- pers. obs.), but is consistent with the two nest bined with narrow criteria for a few key char- visits per day observed for three mainland acters may provide parrots with the flexibility Amazon parrots in northeastern Mexico (En- to exploit a wide range of available cavities kerlin-Hoeflich 1995). Morning and afternoon while limiting predation and competition arrival times, approximately one hour after threats. In addition, low nest site reuse by Li- sunrise and one hour before sunset, for nesting lac-crowned Parrots is contrary to the 30- pairs of the Lilac-crowned Parrot were similar 40% cavity reuse observed for most other par- to the three Amazona species in northeastern rot species (Saunders 1982, Snyder et al. Mexico (Enkerlin-Hoeflich 1995). Large 1987, Rowley and Chapman 1991, Smith cockatoos in dry areas of Australia also re- 1991, Enkerlin-Hoeflich 1995). Natural pre- strict nest visitation activity to the early morn- dation is the main cause of nest failure for ing and late afternoon, spending the hot, mid- Lilac-crowned Parrots (Renton 1998), hence day periods resting under the shade of leafy infrequent cavity reuse may help to prevent trees (Saunders 1982). Lilac-crowned Parrots predators from learning nest site locations at the study site have been noted to demon- (Sonerud 1985, 1989). strate signs of heat stress during the mid-day The Lilac-crowned Parrot is notably differ- hours of 12:00—14:00 by holding wings away ent from other parrot species in its high syn- from their bodies and panting with beaks open chrony in nest initiation, with all nests com- (K.R., pers. obs.). Therefore, restricting feed- mencing within two weeks in each season, ing activity to the early morning and late af- and the general nest initiation period compris- ternoon may enable parrots to conserve en- ing the first three weeks in February. There is ergy during high mid-day temperatures, par- no evidence that breeding pairs of the Lilac- ticularly in dry habitats. crowned Parrot relay after a nest failure, In addition to being infrequent, nest atten- which would also lengthen the nesting period. dance by Lilac-crowned Parrots during feed- Most Amazona species have a 3-5 week nest ing visits was brief. Most Lilac-crowned Par- initiation period each breeding season (Snyder rot activity was conducted away from the nest et al. 1987, Gnam 1991, Enkerlin-Hoeflich area. Nesting pairs were never observed to 1995). The Monk Parakeet (Myiopsitta mon- forage near the nest, and food transfers from achus) in Argentina extends egg-laying over the male to the female took place an average a nine week period (Navarro et al. 1992). Aus- 423 m from the nest. Island Amazon parrots, tralian cockatoos have a similar broad egg- by comparison, may spend longer periods in laying period of 5-8 weeks (Saunders 1982, the nest cavity brooding and preening young Smith and Saunders 1986, Rowley and Chap- (Snyder et al. 1987), as well as conducting man 1991, Smith 1991). The nesting season food transfers and foraging activities near the of the Lilac-crowned Parrot may be so sharply nest (Snyder et al. 1987, Gnam 1991). Infre- defined by the extreme climatic seasonality in quent visits, short nest attendance, and feeding tropical deciduous forest and food resource away from the nest by Lilac-crowned Parrots availability. Nesting pairs may need to fledge may serve to limit the amount of activity in young before the end of the long dry season the nest area, and reduce the risk of attracting in late May-June when food abundance de- predators to the nest. 492 THE WILSON BULLETIN • Vol. Ill, No. 4, December 1999 Breeding birds are restricted by competing flora of the Chamela Bay region, Jalisco, Mexico. demands to maintain their own energetic re- Occas. Pap. Calif. Acad. Sci. 148:1-60. quirements and to protect and nourish the Lott, E. J., S. H. Bullock, and J. A. Solis-Magal- LANES. 1987. Floristic diversity and structure of young (Martin 1987). While infrequent, short upland and arroyo forests of coastal Jalisco. Bio- nest visits may reduce both mid-day energetic tropica 19:228-235. expenditures by foraging adults and the risks Mann, R. E. H. and P. D. Mann. 1978. Breeding of nest predation, there is a cost in having to Finch’s Amazon Parrot (Atnazonafinschi). Avicul. meet the energy demands of the young in a Mag. 84:187-189. shorter time. Hence, variations in nesting be- Martijena, N. E. and S. H. Bullock. 1994. Mono- havior suggest that island and mainland Am- specific dominance of a tropical deciduous forest azon parrots may be employing differing strat- in Mexico. J. Biogeogr. 21:63-74. Martin, T. E. 1987. Food as a limit on breeding birds: egies to meet time constraints in caring for the a life-history perspective. Annu. Rev. Ecol. Syst. young. 18:453-487. ACKNOWLEDGMENTS Navarro, J. L., M. B. Martella, and E. H. Bucher. 1992. Breeding season and productivity of Monk We are grateful to the Cuixmala Ecological Eoun- Parakeets in Cordoba, Argentina. Wilson Bull. 104:413-424. dation for financial and logistical support during the study, and to the Mexican government department of Nilsson, S. G. 1984. The evolution of nest-site selec- SEMARNAP who granted permits for the research. tion among hole-nesting birds: the importance of K.R. received a grant from the Durrell Institute ofCon- nest predation and competition. Ornis Scand. 15: 167-175. servation and Ecology and A.S.M. was supported by the Cuixmala Ecological Foundation and the Denver Perry, D. R. 1978. A method of access into the Zoological Foundation. S. Berman, R. A. Griffiths, D. crowns of emergent and canopy trees. Biotropica V. Fanning, B. Miller, N.ER. Snyder, and an anony- 10:155-157. mous reviewer provided constructive comments on the Perry, D. R. and J. Williams. 1981. The tropical rain manuscript. forest canopy: a method providing total access. Biotropica 13:283-285. LITERATURE CITED Renton, K. 1998. Reproductive ecology and conser- vation of the Lilac-crowned Parrot (Atnazonafin- Bullock, S. H. 1986. Climate ofChamela, Jalisco, and schi) in Jalisco, Mexico. Ph.D. diss., Univ. of trends in the south coastal region ofMexico. Arch. Kent, Canterbury, U.K. Met. Geoph. BiocL, Sen B 36:297-316. Rowley, and G. Chapman. 1991. The breeding bi- I. Chrlstman, B. J. and A. A. Dhondt. 1997. Nest pre- ology, food, social organization, demography and dation in Black-capped Chickadees: how safe are conservation of the Major Mitchell or Pink Cock- cavity nests? Auk 1 14:769-773. atoo, Cacatua leadbeateri, on the margin of the Donahue, P. K. and T. M. Wood. 1995. A safe, flex- Western Australian wheatbelt. Aust. J. Zool. 39: ible, and non-injurious technique for climbing tall 21 1-261. trees. Selbyana 16:196—200. Saunders, D. A. 1979. The availability oftree hollows Enkerlin-Hoeflich, E. C. 1995. Comparative ecology for use as nest sites by White-tailed Black Cock- and reproductive biology of three species ofAma- atoos. Aust. Wild. Res. 6:205—216. zonci parrots in northeastern Mexico. Ph.D. diss., Saunders, D. A. 1982. The breeding behaviour and Texas A & M Univ., Kingsville. biology the short-billed form of the White-tailed Forshaw, J. M. 1989. Parrots of the world, third (re- Black Cockatoo Calyptorhynchus fiinereits. Ibis vised) ed. Lansdowne Editions, Melbourne, Aus- 124:422-455. Gnamt,ralRia.. S. 1991. Nesting behaviour of the Bahama SaunTdheres,avaDi.laAbi,liGt.y Ta.ndSmdiithm,enasinodnsI. oRfowtrleeey.hol1l9o8w2.s Parrot Atnazona leucocephala bahamensis on that provide nest sites for cockatoos (Psittacifonnes) Abaco Island, Bahamas. Acta Congr. Int. Ornithol. in Western Australia. Aust. Wild. Res. 9:541—556. 20:673-680. Smith, G. T 1991. Breeding ecology of the Western Gnamp,oteRn.tiSa.laannddRo.utF.puRtocokfwtehlel.Ba1h9a91m.aRPeaprrroodtucAtmiav-e Long-billed Corella, Cacatua pastihator paslina- zona leucocephala bahamen.sLs. Ibis 133:400- /or. Wild. Res. 18:91-1 10. Smith, G. T. and D. A. Saunders. 1986. Clutch size 405. Fanning, D.V. 1991. Distribution and breeding biol- and productivity in three sympatric species of ogy of the Red-fronted Macaw. Wilson Bull. 103: cockatoo (Psittacifonnes) in the south-west of Western Australia. Aust. Wild. Res. 13:275-285. 357-365. Fanning, D. V. and J. T. Shielett. 1983. Nesting ecol- Snyder, N. E R., J. W. Wiley, and C. B. Kepler. ogy of Thick-hilled Parrots. Condor 85:66-73. 1987. The parrots of Luquillo: natural history and Lorr, E. J. 1993. Annotated checklist of the vascular conservation of the Puerto Rican Parrot. Western Renton and Salinas-Melgoza • LILAC-CROWNED PARROT NESTING BEHAVIOR 493 Foundation of Vertebrate Zoology, Los Angeles, Waltman, J. R. and S. R. Beissinger. 1992. Breeding California. behavior of the Green-rumped Parrotlet. Wilson SoNERUD, G. A. 1985. Nest hole shift in Tengmalm’s Bull. 104:65-84. Owl Aeo}>olius funereiis as defence against nest WiLCOVE, D. S. 1985. Nest predation in forest tracts predation involving long-term memory in the and the decline of migratory songbirds. Ecology predator. J. Anim. Ecol. 54:179-192. 66:121 1-1214. SoNERUD, G. A. 1989. Reduced predation by pine mar- Wilson, K. A., R. Field, and M. H. Wilson. 1995. tins on nests ofTengmalm’s Owl in relocated box- Successful nesting behavior of Puerto Rican Par- es. Anim. Behav. 37:332-334. rots. Wilson Bull. 107:518-529.