Karen T. Mabb

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NATURALIZED (WILD) PARROTS IN CALIFORNIA: A CURRENT ASSESSMENT, 2002.  Karen T. Mabb.  Department of Biological Sciences, California State Polytechnic University, Pomona, CA 91768. kmabb@hotmail.com; www.parrotproject.org

INTRODUCTION

      Parrots have occurred in naturalized populations in Los Angeles County since the 1960s (Hardy 1964, 1973).  Thirteen different naturalized parrot species now occur in Los Angeles County (Garrett 1997). At least two species of parrot that lives in Los Angeles are threatened in the wild.  Red-crowned Parrots (Amazona viridigenalis) and Lilac-crowned Parrots (Amazona finschi) predominate the flock. In their areas of native occurrence in Mexico, Red-crowned Parrots are endangered (CITES 2001 Appendix I) and Lilac-crowned Parrots (Amazona finschi) are threatened (Beissinger and Snyder 1993, Enkerlin-Hoeflich 1995, Hogan and Enkerlin-Hoeflich 1997, Renton 1998). 

     I use the term “naturalized” in accordance with the terminology outlined in Holmes and Stroud (1995), where “naturalized” refers to an established population of organisms that have not been domesticated and “feral” refers to an established population of organisms which have undergone selection under the pressure of domestication.

      My studies of these wild parrots in southern California could have implications in the future conservation policies of these species in their native ranges.  Also, as human influence increases, urban habitats (or at least human-dominated landscapes) will become the primary habitats for birds. Understanding the ecology of newly urban species will shed light on the ecology of the future.

       The intent of this paper is to provide an update regarding the current status and distribution of parrots in California.  Garrett (1997) only discussed populations in southern California, had little data from Orange County, none from San Bernardino County, and none from San Diego County.

METHODS

     I have conducted detailed studies regarding parrot occurrence in the San Gabriel Valley, California, from May 1995-December 2002. I have identified seasonal roost locations and patterns within a larger general roost area (Mabb in prep.).   In addition to my own observations, I have solicited information regarding parrots from ornithologists, bird-watchers, and the general public and I use these data to assess the summary status and distribution of psittaciform species occurring in the wild in California. When possible, observations of large or unusual groups of parrots have been confirmed by the author or by persons known to the author.  The author has also confirmed the distribution of these species by personal direct observation, except in San Diego County.

RESULTS

     Over 1000 written observation forms have been submitted to the Los Angeles County Natural History Museum (Garrett 1997) and these have been updated with over 100 electronic submissions entered into a shared database with the Los Angeles Audubon Education Center at Debs Park.

Table 1.  Population Estimates for Parrots in California by Region^a

^aTable adapted from Garrett 1997 (italics indicate number has changed since Garrett 1997)

^bSFV, San Fernando Valley, Los Angeles Co. (including Simi Valley, Ventura Co.); SGV, San Gabriel Valley, Los Angeles Co.; NC, north coast, from Malibu to Pacific Palisades, Los Angeles Co; LA, Los Angeles Basin; SC, south coast, from Manhattan Beach to Palos Verdes Peninsula and Long Beach, Los Angeles Co.; OR, Orange Co.; SD, San Diego Co.; RED, Redlands and Mentone, San Bernardino Co.; BAK, Bakersfield, Kern Co.; SF, San Francisco Bay area, Alameda Co., San Francisco Co., Santa Clara Co.

Rose-ringed Parakeet (Psittacula krameri)

      The population in the San Gabriel Valley has risen by a few members.  Young are present every year, but the lack of significant population growth suggests high mortality.  The population in the north coast has disappeared entirely.  The large population, 700+, in Bakersfield were not reported to parrot researchers until after the publication of Garrett 1997, but it has been reported to have been established in 1977 (Sheehey unpubl.)  This species has also been reported in Redlands, but researchers have thus far failed to confirm this report (Malcolm pers. comm.)  There have only been 4 Rose-ringed Parakeets reported in San Diego (John Martin per.comm.), but none have been reported as breeding.

Blue-crowned Parakeet (Aratinga acuticaudata)

     Populations of this species appear to be relatively stable and small.  Most flocks are usually under 10 individuals.  The flock in the San Gabriel Valley (Temple City) has had only a few new members presumably due to reproductive recruitment.

Mitred Parakeet (Aratinga mitrata)

      This species appears to have undergone a population surge.  The population in Orange County is estimated at 100, the population in south coast (Long Beach) has increased by 50 parakeets, and they have also increased in the Los Angeles Basin.   San Diego reports a modest population of 20.  Garrett (1997) reported their total number to be 683 and Mabb (1997a) reported the number in the San Gabriel Valley to be less than 100.  Now, the population in the San Gabriel Valley has grown to 400 and the total population has increased to over 1000.

Red-masked Parakeet (Aratinga erythrogenys)

      This parakeet species has also experienced a population boom.  Garrett (1997) reported the total to be 70 and Mabb (1997a) reported the San Gabriel Valley population to be 25.  Now, the San Gabriel Valley population is estimated to be 130-180 birds and the total estimate for this species is 285-345 parakeets.  This appears to be the predominant Aratinga species in San Diego, which reported a population of 80.

Black-hooded Parakeet (Nandayus nenday)

      The San Gabriel Valley population has remained relatively constant.  Their numbers have increased to 100 in the north coast (Malibu).

White-winged Parakeet (Brotogeris chiriri)

      These appear to only be successful in San Francisco, but their numbers are declining.  In the 1970s these were the more prevalent species of Brotogeris, but have since been replaced by the similar Yellow-chevroned Parakeet.

Yellow-chevroned Parakeet (Brotogeris versicolurus)

      Numbers appear to be increasing in the San Gabriel Valley, the San Fernando Valley, and the Los Angeles Basin.  This parakeet tends to be associated with cultivated date palms and Silk Floss Trees (Chorisia speciosa).  I anticipate these to continue to increase, as they are not exploiting all of the available suitable habitat.  Also, the trees that this species are associated with have been used extensively in recently built strip mall parking lots and housing subdivisions, and the trees have not reached maturity.

Lilac-crowned Parrot (Amazona finschi)

      This parrot is increasing in the San Gabriel Valley due to breeding activity.  Also, observers are learning to better distinguish it from the similar-looking Red-crowned Parrot.  In Orange County, the current reported population number is higher than Garrett (1997) largely due to increased scrutiny by the local parrot investigator.

Red-crowned Parrot (Amazona viridigenalis)

      This is the most abundant parrot in California.  The San Gabriel Valley has seen a tremendous increase in the population of this species.  Also, there are significant populations of this species in Orange County.  A small population of this species is reported to have bred in the city of Redlands and local residents report that this population has been present in the area for a time period on the order of decades.  In San Diego County, there are two populations of this parrot in approximately equal numbers (John Martin pers. comm.)

Yellow-headed Parrot (Amazona oratrix)

      These were more numerous decades ago (Hardy 1973), but have since declined.  They have continued to decline from their numbers reported by Garrett (1997).

Blue-fronted Parrot (Amazona aestiva)

      These parrots occur in few numbers.  They are found within the mixed parrot species roost flock.  Their numbers appear to be sustained by repeated escapes and by individuals that are long-lived.  Breeding evidence has only been reported once in the San Gabriel Valley.

Red-lored Parrot (Amazona autumnalis)

     This species has increased from 2 (Mabb 1997a) to 4-6 in the San Gabriel Valley.  Young have been observed being attended by parents, so reproductive recruitment is suspected.

Blue and Gold Macaw (Ara ararauna)

     A pair of this macaw species has been reported as nesting in a billboard in San Diego.  This pair appears to be persistent due to their long lives and their ability to elude being collected by humans.  It is rumored that humans collected their eggs, disrupting a breeding attempt.

DISCUSSION

       In the fall and winter, roost flocks of over 1000 Red-crowned and Lilac-crowned parrots are observed regularly in the San Gabriel Valley (Mabb 1997a, 1997b). The highest number of 1447 parrots was observed on 8 February 2000. I also found that parrots roosted in only six kinds of trees and that they had a seasonal preference in their usage (Mabb 1997a).  The best method for censusing these mixed species roost flocks appears to be counting parrots in the afternoon/evening with several observers as the parrots enter their nocturnal roost in the winter.  In winter, they roost in large flocks, the flock is most mixed, and they select evergreen trees presumably because there are no other suitable alternatives available (Mabb in prep.)

       Identification of parrot species is difficult.  When they are entering the roosts, they often appear as silhouettes at best, and it requires trained observers to distinguish to the level of species.  It is likely that many parrot species are misreported.  Mitred Parakeet, Red-masked Parakeet, and Blue-crowned Parakeet are often only identified to genus.  Lilac-crowned Parrots are often reported as Red-crowned Parrots and vice versa according to what an observer knows was reported previously.  I have undertaken a training program whereby I teach parrot identification criteria and have seen limited results in improvement of the bird-watching community.  Additionally, recent improvements in parrot identification criteria in North American bird field guides have improved identification resolution.

CONCLUSION

       Some parrots could become harmful invasive pest species (Fisk and Crabtree 1974, Shelgren et al.1975). Black-hooded Parakeets occur in sycamore canyons along the coast and in the foothills along the urban/wildlife interface in the San Gabriel Valley.  Black-hooded Parakeets occur in areas where populations of native animals still persist and this species needs to be closely monitored.  Two pairs of Lilac-crowned Parrots have been observed nesting in wild areas of the San Gabriel Mountains (Mabb pers. obs.).  According to Renton (1998) this species nests on mountainsides in western Mexico.  Mountainsides are among the few natural areas remaining in southern California, thus the potential to compete with native animals for nesting substrate must be explored.  Bakersfield is an agricultural area where many of California’s nut crops are grown.  Rose-ringed Parakeets are notorious grain pests in many areas around the world.  If the population of Rose-ringed Parakeets were to leave the urban areas and enter agricultural areas, the potential for economic loss would become eminent.  We need to study all these parrots to find out how they live in California and whether they could become pests in the future.

      At least two species of parrot that lives in California are threatened in the wild. Red-crowned Parrots are endangered in northeastern Mexico and Lilac-crowned Parrots are threatened in western Mexico. Understanding the factors that lead to the proliferation of these parrot species could be important to understanding their survival and biology. The estimated total wild population of Red-crowned Parrots is 10,000 (Ernesto Enkerlin-Hoeflich, Claudia Macias pers. comm.), thus, according to my population number estimate, California has over 25% of the world’s wild Red-crowned Parrots.  What kind of irony is that?

      Furthermore, urban ecology is an important area of study.  Urban habitats are increasing at an alarming rate. Understanding the ecology of newly urban species may also aid in understanding the future parrots face in their native areas, as those areas, too, are experiencing economic growth, increase in human population, and urban sprawl.

ACKNOWLEDGEMENTS

I thank Kimball L. Garrett, Charles T. Collins, James Malcolm, Walter Piper, Phil Unitt, Larry W. Allen, Alison M. Sheehey, Daniel S. Cooper, and Thomas P. Ryan for so graciously and expeditiously providing data and follow-up information at such short notice.   I cannot possibly thank all of the observers individually, but this research is not possible without each and every parrot report submission that we have received.

LITERATURE CITED

Beissinger, S. R., and N. F. R. Snyder, eds.  1993.  New World Parrots in Crisis.  Smithsonian Institution Press, Washington and London.

Enkerlin-Hoeflich, E.C. 1995. Comparative ecology and reproductive biology of three species of Amazona parrots in northeastern Mexico. Ph.D. dissertation, Texas A & M Univ., College Station.

Fisk, L.H., and D.M. Crabtree. 1974. Black-hooded Parakeet: New feral breeding species in California? Am. Birds 28:11-13.

Garrett, K.L. 1997. Population status and distribution of naturalized parrots in southern California. W. Birds 28:181-195.

Hardy, J.W. 1964. Ringed parakeets nesting in Los Angeles, California. Condor 66:445-447.

Hardy, J.W. 1973. Feral exotic birds in southern California. Wilson Bull. 85:506-512.

Hogan, K. M., and Enkerlin-Hoeflich, E. C. 1997.  Red-crowned Parrot (Amazona viridigenalis), in The Birds of North America, No. 292 (A. Poole and F. Gill, eds.). Acad. Nat. Sci. Philadelphia.

Holmes, J. S., and Stroud, D. A. 1995.  Letter: Naturalised birds: feral, exotic, introduced, or alien?  Br. Birds 88:602-603. 

Mabb, K. T. 1997a.  Roosting behavior of naturalized parrots in the San Gabriel Valley, California.  W. Birds 28(4):202-208.

Mabb, K. T. 1997b.  Nesting behavior of Amazona parrots and Rose-ringed Parakeets in the San Gabriel Valley, California.  W. Birds 28(4): 209-217.

Mabb, K.T. In prep.(2002). Seasonal patterns in parrot roost flocks in the San Gabriel Valley, California: size, composition, tree usage, and site location.

Renton, K. 1998.  Reproductive ecology and conservation of the Lilac-crowned Parrot (Amazona finschi) in Jalisco, Mexico.  Ph.D. dissertation.  University of Kent at Canterbury, Kent, U. K.

Ryan, T.P. Unpubl. Status and distribution of naturalized parrot populations in the San Francisco Bay area.

Shelgren, J.H., R.A. Thompson, T.K. Palmer, M.O. Keffer, D.O. Clark, and J. Johnson. 1975. An evaluation of the pest potential of the Ring-necked Parakeet, Nanday Conure and the Canary-winged Parakeet in California. Calif. Dept. Food and Agric., Div. Plant Industry Special Services Unit, Sacramento.

Sheehey, A.M. Unpubl. Notes on the status and distribution of Rose-ringed Parakeets (Psittacula krameri) in Bakersfield, California.