Purple Finch

Distribution and Abundance

• BBS Map | CBC Map
• Breeding range northern United States, southern and central Canada,  and the west coast of North America.
• Range appears to have contracted from northern Illinois and Indiana and southern Appalachian mountains over the past 80 years; no appreciable changes in range, however, over the past 30 years (BBS data).
• Decline of 50% in breeding population in the northeast United States and southern Canada, 1966-1994. Densities much higher in western and northeastern coastal populations than in other portions of the breeding range (BBS data).
• In eastern North America, migration characterized by biennial incursions into southern United States. Variability in extent of migration attributed to variation in conifer cone crops in northern portion of winter range (Blake 1962, 1967, Kennard 1977). Numbers often decline in northern areas as winter progresses (Janssen 1987, Peterjohn 1980).
• Winter range in eastern United States and southern Canada. In the west, migrates into lower-elevation areas (Small 1994).

Habitat

• Breeds primarily in moist or cool coniferous forests; also frequently found in mixed coniferous-deciduous forest, edges of bogs, and riparian corridors. Also breeds in deciduous forests, ornamental plantations, orchards, pastures and lawns with scattered conifers and shrubs, hedgerows, and developed areas.
• In Wisconsin, 35% of 468 observations from 1995-2000 were in upland mixed forest (with spruce or pine) and 21.6% in urban areas, particularly rural residential areas and farmsteads (WSO 2002). In Michigan, this species prefers coniferous forests, mixed forests, and in the northern part of the state, conifer and ornamental plantings near homes (Brewer et al. 1991).
• Analysis of vegetation structure for a population breeding in fragmented aspen-red maple woodland in New York finds a strong correlation in breeding density with relative ratio of forest edge to forest area and with density of understory vegetation (Keller 1990).
• Winter habitats include coniferous, deciduous, mixed coniferous-deciduous forests, urban and suburban areas, mixed shrub and conifer, weedy fields, and hedgerows. Habitat choice likely dictated by availability of food resources.

Behavior

• Diet mainly seeds, buds, nectar, and fruit; occasionally insects.
• Monogamous mating system; pairs solitary during breeding season.
• Will peck opponents (Popp 1987). Males and females exhibit aggressive behavior toward both sexes.  In intraspecific interactions between the sexes, females displaced males at a much higher rate (Shedd 1990).
• Continual experimental removal of territorial males resulted in a consistent influx of replacement males (Hemsley and Cope 1951), which suggests a large population of floating nonbreeders, a situation consistent with territory establishment.
• No reports of interspecific territoriality, although aggression reported between Purple Finches and Pine Siskins and American Goldfinches (Popp 1990) and House Finches (Shedd 1990). 
• High rates of breeding area fidelity (Magee 1936, Yunick 1987).
• During winter, forage and roost in single and multi-species flocks  with Pine Siskins and American Goldfinches (Laskey 1958, Popp 1988).

Parasitism and Predation

• Of 372 nests studied (Nest Record Card Program and Western Foundation of Vertebrate Zoology), parasitism rate by Brown-headed Cowbird was 5.9%. Long-range studies indicate parasitism rate has not changed appreciably since 1926.
• Parasitism rates significantly higher in eastern than in western nests; patterns and rates similar to those of House Finch (Wootton 1986). However, in Wisconsin, of 477 confirmed Brown-headed Cowbird observations from 1995-2000, Purple Finch was not indicated as a host species, whereas House Finch was indicated in 6 of the 477 observations (WSO 2002).
• Accepts cowbird eggs when its own eggs are present; abandons nest when only cowbird eggs are present (Rothstein 1975).
• Purple Finch not a good host for cowbird because it feeds nestlings mostly seeds (Eastzer et al. 1980); cowbird young need a predominately insect diet to develop well.
• Recorded predators on adults include Blue Jay, Barn Owl, Merlin, Sharp-shinned Hawk, American Kestrel, domestic cat and domestic dog. Eggs and young consumed by Blue Jay, Common Grackle and red squirrel.

Conservation and Management

• Although legislation prohibits shooting and trapping, 14% of recoveries of banded Purple Finches were shot without scientific permits and 3% were caught in snares (Collister 1989); additional sources of mortality include collision with motor vehicles, windows and other stationary objects.
• Moderate logging potentially beneficial because this species prefers open wooded habitats (Keller 1990). Extensive clearcutting, however, likely to reduce population by eliminating habitat (Verner and Larson 1989).
• Decline of 50% in breeding populations in northeast United States and southern Canada (BBS data, Hall 1984) strongly attributed with invasion of House Finches in eastern North America, not with changes in climatic or habitat variables, indicating interspecific competition (Wootton 1987, Shedd 1990). 
• BBS trend results from 1966-2000 (Sauer et al. 2001) in the Northern Spruce-Hardwoods region indicate a significant population decline of the Purple Finch in this region  (-2.7, p=0.00 Trend Graph S28), as is the case in the Great Lakes Transition region (-3.6, p=0.07 Trend Graph S20). Survey-wide (US and Canada), this species has exhibited an overall decline in population (-1.8, p=0.00 Trend Graph SUR).

References

• Blake, C.H. 1962. Further notes on Purple Finches. Bird-Banding 33:173-180.
• Blake, C.H. 1967. Purple Finches at Hillsborough, N.C. 1961-1965. Bird-Banding 38:1-17.
• Brewer, R., G.A. McPeek and R.J. Adams, Jr. 1991. The atlas of breeding birds of Michigan. Michigan State University Press, East Lansing.
• Collister, D. 1989. Migration, wintering range, longevity and mortality of Alberta Purple Finches as eveidence by banding data. Alberta Bird Record 7:3-8.
• Eastzer, D., P.R. Chu and A.P. King. 1980. The young cowbird: average or optimal nestling? Condor 82:417-425.
• Hall, G.A. 1984. A long-term bird population study in an Appalachian spruce forest. Wilson Bulletin 96:228-240.
• Hemsley, M.M. and J.B. Cope. 1951. Further data on removal and repopulation of the breeding birds in a spruce-fir forest community. Auk 68:483-493.
• Janssen, R.B. 1987. Birds in Minnesota. University of Minnesota Press, Minneapolis, MN.
• Keller, J.K. 1990. Using aerial photography to model species-habitat relationships: the importance of habitat size and shape. N.Y. State Mus. Bull. 471:34-46.
• Kennard, J.H. 1977. Biennial rhythm in Purple Finch migration. Bird-Banding 48:155-157.
• Laskey, A.R. 1974. A winter roost of Purple Finches. Auk 75:475-476.
• Magee, M.J. 1936. The average age of the eastern Purple Finch: an estimate based on returns and recoveries. Bird-Banding 7:161-162.
• Peterjohn, B.G. 1989. The birds of Ohio. Indiana University Press, Bloomington, IN.
• Popp, J.W. 1988. Scanning behavior in finches in mixed-species groups. Condor 90:510-512.
• Popp, J.W. 1990. Use of agonistic displays by Purple Finches during interspecific encounters. Bird Behavior 8:48-50.
• Rothstein, S.I. 1975. An experimental and teleonomic investigation of avian brood parasitism. Condor 77:250-271.
• Sauer, J.R., J.E. Hines and J. Fallon. 2001. The North American Breeding Bird Survey, Results and Analysis 1966-2000. Version 2001.2, USGS Patuxent Wildlife Research Center, Laurel, MD.
• Shedd, D.H. 1990. Aggressive interactions in wintering House Finches and Purple Finches. Wilson Bulletin 102:174-178.
• Small, A. 1994. California birds: their status and distribution. Ibis Publ. Co., Vista, CA.
• Verner, J. and T.A. Larson. 1989. Richness of breeding bird species in mixed-conifer forests of the Sierra Nevada, California. Auk 106:447-463.
• Wisconsin Society for Ornithology. 2002. Wisconsin Breeding Bird Atlas.
• Wootton, J.T. 1986. Clutch-size differences in western and introduced eastern populations of House Finches: patterns and hypotheses. Wilson Bulletin 98:459-462.
• Wootton, J.T. 1987. Interspecific competition between introduced House Finch populations and two associated passerine species. Oecologia 71:325-331.
• Yunick, R.P. 1987. Seven multiple-recapture encounters with banded birds. N. Am. Bird Bander 12:60-63.