Loxia curvirostra - Linnaeus, 1758
Red Crossbill
Other English Common Names: red crossbill
Taxonomic Status: Accepted
Related ITIS Name(s): Loxia curvirostra Linnaeus, 1758 (TSN 179259)
French Common Names: bec-croisé des sapins
Spanish Common Names: Picotuerto Rojo
Unique Identifier: ELEMENT_GLOBAL.2.1009908
Element Code: ABPBY05050
Informal Taxonomy: Animals, Vertebrates - Birds - Perching Birds
 
Kingdom Phylum Class Order Family Genus
Animalia Craniata Aves Passeriformes Fringillidae Loxia
Genus Size: B - Very small genus (2-5 species)
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Concept Reference
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Concept Reference: American Ornithologists' Union (AOU). Chesser, R.T., K.J. Burns, C. Cicero, J.L. Dunn, A.W. Kratter, I.J. Lovette, P.C. Rasmussen, J.V. Remsen, Jr., J.D. Rising, D.F. Stotz, and K. Winker. 2017. Fifty-eighth Supplement to the American Ornithologists' Union Check-list of North American Birds. The Auk 134:751-773.
Concept Reference Code: A17AOU01EHUS
Name Used in Concept Reference: Loxia curvirostra
Taxonomic Comments: Loxia sinesciuris was formerly considered conspecific with L. curvirostra, but treated as a separate species on the basis of high levels of premating reproductive isolation (Smith and Benkman 2007, Benkman et al. 2009), despite regular and likely long-term sympatric breeding of multiple call types of Red Crossbill, and genomic differences (Parchman et al. 2016) (AOU 2017).
Conservation Status
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NatureServe Status

Global Status: G5
Global Status Last Reviewed: 09Apr2016
Global Status Last Changed: 04Dec1996
Ranking Methodology Used: Ranked by inspection
Rounded Global Status: G5 - Secure
Reasons: Widespread in North America and Eurasia; large population size; many occurrences, though these are variable in location; apparently stable or slowly declining overall in North America but trends are difficult to determine; taxonomic status is uncertain, and status and rank could change significantly if ongoing research confirms the suspicion that L. curvirostra consists of multiple species.
Nation: United States
National Status: N5 (19Mar1997)
Nation: Canada
National Status: N5B,N5N,N5M (29Jan2018)

U.S. & Canada State/Province Status
Due to latency between updates made in state, provincial or other NatureServe Network databases and when they appear on NatureServe Explorer, for state or provincial information you may wish to contact the data steward in your jurisdiction to obtain the most current data. Please refer to our Distribution Data Sources to find contact information for your jurisdiction.
United States Alabama (S1B), Alaska (S4), Arizona (S4), Arkansas (S1), California (SNR), Colorado (S5), Connecticut (SNA), District of Columbia (S1N), Georgia (SU), Idaho (S4), Illinois (S1), Indiana (S1N), Iowa (S2N), Kansas (SNA), Kentucky (SNA), Maine (S3S4B,S3S4N), Massachusetts (S1B,S4N), Michigan (S3), Minnesota (SNRB,SNRN), Missouri (SNA), Montana (S5), Navajo Nation (S3S4), Nebraska (S4), Nevada (S5), New Hampshire (SNA), New Jersey (SNA), New Mexico (S4B,S4N), New York (S2S3), North Carolina (S3B,S3N), North Dakota (SNA), Ohio (SNRN), Oklahoma (S1N), Oregon (S4), South Carolina (S4), South Dakota (S4B,S3N), Tennessee (S1B,S2N), Texas (S3), Utah (S2S3), Vermont (S1B,S2N), Virginia (S1), Washington (S4B), West Virginia (S2N), Wisconsin (S2?B), Wyoming (S5B,S5N)
Canada Alberta (S4), British Columbia (S5), Manitoba (S3), New Brunswick (S3), Newfoundland Island (S1S2), Northwest Territories (S4), Nova Scotia (S3S4), Ontario (S4B), Prince Edward Island (S1B), Quebec (S4), Saskatchewan (S4B,S5N), Yukon Territory (S5)

Other Statuses

Implied Status under the Committee on the Status of Endangered Wildlife in Canada (COSEWIC):PS:T
Comments on COSEWIC: Subspecies percna is considered a distinctive taxonomic group, with breeding likely restricted to the island of Newfoundland. Various population estimates suggest that it is has declined markedly and steadily over the last 50 years, along with declines in the extent and quality of its habitat. A few records of the percna subspecies exist for Nova Scotia and other locations, but there is not enough information to determine its status there.

Designated Endangered in May 2004. Status re-examined and designated Threatened April 2016.

IUCN Red List Category: LC - Least concern

NatureServe Global Conservation Status Factors

Range Extent: >2,500,000 square km (greater than 1,000,000 square miles)
Range Extent Comments: As traditionally defined, this species occurs widely in Eurasia and North America. In North America it is resident from southeastern Alaska eastward across boreal Canada to Newfoundland and Nova Scotia, and south in the west to northern Baja California and through the mountains to Nicaragua, and south in the east to Great Lakes region, southern Appalachian Mountains, New York, and New England. (Adkisson 1996, AOU 1998). In the nonbreeding season this species disperses irregularly throughout much of the remainder of the contiguous United States. The several types or species of red crossbills are highly nomadic and may shift breeding ranges by as much as a thousand miles between one breeding season and the next (Groth 1993).

Number of Occurrences: > 300
Number of Occurrences Comments: This species is represented by a large number of occurrences (subpopulations), but crossbills are not permanent residents of any particular occurrence.

Population Size: >1,000,000 individuals
Population Size Comments: Total population size is unknown but presumably exceeds 1,000,000. Rich et al. (2004) estimated population size at 15,000,000.

Number of Occurrences with Good Viability/Integrity: Very many (>125)
Viability/Integrity Comments: Many occurrences appear to have at least good estimated viability.

Overall Threat Impact: Medium
Overall Threat Impact Comments: Decline of the Newfoundland population (subspecies percna) evidently has been due at least in part to competition from the introduced red squirrel (Benkman 1993).

Local declines and increases reflect variations in local conifer cone crops; widespread deforestation or low cone availability results in emigration of crossbills to other areas. Net reduction in total area of mature forest (or in overall cone availability) presumably would result in an overall decline in the crossbill population, so recent forestry practices and widespread regional tree mortality due to insect outbreaks likely are detrimental to crossbills, at least temporarily.

Short-term Trend: Decline of <30% to relatively stable
Short-term Trend Comments: Trends are difficult to determine because of the species' nomadic habits, but probably the overall population is relatively stable or slowly declining.

Long-term Trend: Unknown
Long-term Trend Comments: The "northeastern" subspecies declined probably due to extensive logging in the early 1900s (Dickerman 1987). Newfoundland population (subspecies percna) has declined greatly since the late 1950s and early 1960s (Benkman 1993).

Breeding Bird Survey (BBS) data for 1966-2007 indicate a significant survey-wide decline averaging 1.4% per year; this amounts to a decline of 44% over this time period. In most areas, this species is detected in low numbers during these surveys. For example, BBS abundance (average number of individuals per route) declined from 1.9-2.3 in the 1960s and early 1970s to 1.2-1.5 in 2000-2007, so the decline was not more than about 1 bird per route.

Christmas Bird Count (CBC) data for Canada and the United States for this period show large annual fluctuations in abundance, with no obvious increasing or decreasing trend.

Populations of this species may not be accurately represented by data collected by BBS or CBC methods. Apparent changes in abundance in count areas may actually reflect irregular/irruptive population movements with no net change in overall range-wide abundance.

Other NatureServe Conservation Status Information

Protection Needs: To conserve the diversity of red crossbills, Benkman (1993) recommended protecting mature and old-growth stands, increasing rotation ages throughout the range of each of the required conifers, and leaving mature trees in cutover areas.

Distribution
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Global Range: (>2,500,000 square km (greater than 1,000,000 square miles)) As traditionally defined, this species occurs widely in Eurasia and North America. In North America it is resident from southeastern Alaska eastward across boreal Canada to Newfoundland and Nova Scotia, and south in the west to northern Baja California and through the mountains to Nicaragua, and south in the east to Great Lakes region, southern Appalachian Mountains, New York, and New England. (Adkisson 1996, AOU 1998). In the nonbreeding season this species disperses irregularly throughout much of the remainder of the contiguous United States. The several types or species of red crossbills are highly nomadic and may shift breeding ranges by as much as a thousand miles between one breeding season and the next (Groth 1993).

U.S. States and Canadian Provinces

Due to latency between updates made in state, provincial or other NatureServe Network databases and when they appear on NatureServe Explorer, for state or provincial information you may wish to contact the data steward in your jurisdiction to obtain the most current data. Please refer to our Distribution Data Sources to find contact information for your jurisdiction.
Color legend for Distribution Map
NOTE: The maps for birds represent the breeding status by state and province. In some jurisdictions, the subnational statuses for common species have not been assessed and the status is shown as not-assessed (SNR). In some jurisdictions, the subnational status refers to the status as a non-breeder; these errors will be corrected in future versions of these maps. A species is not shown in a jurisdiction if it is not known to breed in the jurisdiction or if it occurs only accidentally or casually in the jurisdiction. Thus, the species may occur in a jurisdiction as a seasonal non-breeding resident or as a migratory transient but this will not be indicated on these maps. See other maps on this web site that depict the Western Hemisphere ranges of these species at all seasons of the year.
Endemism: occurs (regularly, as a native taxon) in multiple nations

U.S. & Canada State/Province Distribution
United States AK, AL, AR, AZ, CA, CO, CT, DC, GA, IA, ID, IL, IN, KS, KY, MA, ME, MI, MN, MO, MT, NC, ND, NE, NH, NJ, NM, NN, NV, NY, OH, OK, OR, SC, SD, TN, TX, UT, VA, VT, WA, WI, WV, WY
Canada AB, BC, MB, NB, NF, NS, NT, ON, PE, QC, SK, YT

Range Map
No map available.


U.S. Distribution by County Help
State County Name (FIPS Code)
NC Ashe (37009), Avery (37011), Buncombe (37021), Burke (37023), Caldwell (37027), Haywood (37087), Jackson (37099), McDowell (37111), Mitchell (37121), Swain (37173), Transylvania (37175), Watauga (37189), Yancey (37199)
VA Highland (51091)*, Rockingham (51165)
VT Essex (50009)
* Extirpated/possibly extirpated
U.S. Distribution by Watershed Help
Watershed Region Help Watershed Name (Watershed Code)
01 Passumpsic (01080102)+
02 South Branch Potomac (02070001)+, South Fork Shenandoah (02070005)+, Upper James (02080201)+*
03 Upper Catawba (03050101)+, Seneca (03060101)+
05 Upper New (05050001)+, Greenbrier (05050003)+*
06 Watauga (06010103)+, Upper French Broad (06010105)+, Pigeon (06010106)+, Nolichucky (06010108)+, Tuckasegee (06010203)+
+ Natural heritage record(s) exist for this watershed
* Extirpated/possibly extirpated
Ecology & Life History
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Reproduction Comments: Breeding season is variable, depends in part on food supply. Clutch size is 3-4, sometimes 5. Incubation, by female (fed by male), lasts about 12-14 days. Young leave nest about 17 days after hatching (Terres 1980), may be fed for two more weeks.
Ecology Comments: Forms flocks when not breeding; does not maintain a feeding territory. Pairs may forage more than 500 meters from nest (Bailey 1953, Nethersole-Thompson 1975).
Non-Migrant: Y
Locally Migrant: N
Long Distance Migrant: N
Mobility and Migration Comments: Wanders irregularly when population high and or food supply low (Terres 1980).
Terrestrial Habitat(s): Forest - Conifer, Forest - Mixed, Savanna, Woodland - Conifer, Woodland - Mixed
Habitat Comments: Coniferous and mixed coniferous-deciduous forests; also pine savanna and pine-oak habitat. In migration and winter may also occur in deciduous forest, and more open scrubby areas.

Nests in conifers, 1.5-25 m above ground, toward outer end of branch (Terres 1980).

Adult Food Habits: Granivore, Invertivore
Immature Food Habits: Granivore, Invertivore
Food Comments: Eats seeds, buds, and insects. Forages in trees; also picks up seeds from the ground. Feeds on a wide variety of seeds: e.g., pine, fir, spruce, hemlock, larch, birch, alder, elm, etc. (Terres 1980); mostly conifer seeds (Benkman 1990).
Adult Phenology: Diurnal
Immature Phenology: Diurnal
Length: 16 centimeters
Weight: 37 grams
Economic Attributes Not yet assessed
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Management Summary
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Management Requirements: To conserve the diversity of red crossbills, Benkman (1993) recommended protecting mature and old-growth stands, increasing rotation ages throughout the range of each of the required conifers, and leaving mature trees in cutover areas.
Population/Occurrence Delineation
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Group Name: Passerines

Use Class: Breeding
Subtype(s): Foraging Area, Nest Site, Nesting Colony
Minimum Criteria for an Occurrence: Evidence of historical breeding, or current and likely recurring breeding, at a given location, minimally a reliable observation of one or more breeding pairs in appropriate habitat. Be cautious about creating EOs for observations that may represent single breeding events outside the normal breeding distribution.

Mapping Guidance: Breeding occurrences include nesting areas as well as foraging areas.

For swallows and other species that have separate nesting and foraging areas, separations are based on nest sites or nesting areas, not to locations of foraging individuals. For example, nesting areas separated by a gap larger than the separation distance are different occurrences, regardless of the foraging locations of individuals from those nesting areas. This separation procedure is appropriate because nesting areas are the critical aspect of swallow breeding occurrences, tend to be relatively stable or at least somwhat predictable in general location, and so are the basis for effective conservation; foraging areas are much more flexible and not necessarily static.

Separation Distance for Unsuitable Habitat: 5 km
Separation Distance for Suitable Habitat: 5 km
Separation Justification: Significant dispersal and associated high potential for gene flow among populations of birds separated by tens of kilometers (e.g., Moore and Dolbeer 1989), and increasing evidence that individuals leave their usual home range to engage in extrapair copulations, as well as long foraging excursions of some species, make it difficult to circumscribe occurrences on the basis of meaningful population units without occurrences becoming too large. Hence, a moderate, standardized separation distance has been adopted for songbirds and flycatchers; it should yield occurrences that are not too spatially expansive while also accounting for the likelihood of gene flow among populations within a few kilometers of each other.

Be careful not to separate a population's nesting areas and foraging areas as different occurrences; include them in the same occurrence even if they are more than 5 km apart. Mean foraging radius (from nesting area) of Brown-headed Cowbird females was 4.0 kilometers in California, 1.2 kilometers in Illinois-Missouri (Thompson 1994). Yellow-headed Blackbirds, Brewer's Blackbirds, and probably Red-winged Blackbirds all forage up to 1.6 kilometers away from breeding colony (Willson 1966, Horn 1968). In one study, Brewer's Blackbirds were found as far as 10 kilometers from nesting area (Williams 1952), but this may be unusual.

For swallows and other parrerines with similar behavioral ecology, separation distance pertains to nest sites or nesting colonies, not to locations of foraging individuals. For example, nesting areas separated by a gap of more than 5 km are different occurrences, regardless of the foraging locations of individuals from those nesting areas. This separation procedure is appropriate because nesting areas are the critical aspect of swallow breeding occurrences, tend to be relatively stable or at least somwhat predictable in general location, and so are the basis for effective conservation; foraging areas are much more flexible and not necessarily static.

Be cautious about creating EOs for observations that may represent single breeding events outside the normal breeding distribution.

Unsuitable habitat: Habitat not normally used for breeding/feeding by a particular species. For example, unsuitable habitat for grassland and shrubland birds includes forest/woodland, urban/suburban, and aquatic habitats. Most habitats would be suitable for birds with versatile foraging habits (e.g., most corvids).

Date: 10Sep2004
Author: Hammerson, G.

Use Class: Migratory stopover
Subtype(s): Foraging Area, Roost Site
Minimum Criteria for an Occurrence: For most passerines: Evidence of recurring presence of migrating individuals (including historical) and potential recurring presence at a given location; minimally a reliable observation of 25 birds in appropriate habitat.

For swallows: Evidence of recurring presence of migrating flocks (including historical) and potential recurring presence at a given location; minimally a reliable observation of 100 birds in appropriate habitat (e.g., traditional roost sites).

Occurrences should be locations where the species is resident for some time during the appropriate season; it is preferable to have observations documenting presence over at least 7 days annually.

EOs should not be described for species that are nomadic during nonbreeding season: e.g., Lark Bunting.

Be cautious about creating EOs for observations that may represent single events.

Separation Distance for Unsuitable Habitat: 5 km
Separation Distance for Suitable Habitat: 5 km
Separation Justification: Separation distance somewhat arbitrary but intended to define occurrences of managable size for conservation purposes. Occurrences defined primarily on the basis of areas supporting concentrations of birds, rather than on the basis of distinct populations.

For swallows and other species with similar behavioral ecology, the separation distance pertains to communal roost sites rather than to foraging areas; the former tend to be more stable and specific over time than the latter.

Date: 03Sep2004
Author: Hammerson, G., and S. Cannings

Use Class: Nonbreeding
Subtype(s): Foraging Area, Roost Site
Minimum Criteria for an Occurrence: Any area used traditionally in the nonbreeding season (used for populations that are not resident in a location year-round). Minimally, reliable observations of 10 or more individuals in appropriate habitat for 20 or more days at a time. For G1-G3 species, observations of fewer individuals could constitute an occurrence of conservation value. Sites used during migration should be documented under the 'migratory stopover' location use class.

Separation Distance for Unsuitable Habitat: 5 km
Separation Distance for Suitable Habitat: 5 km
Separation Justification: Separation distance is necessarily arbitrary but attempts to balance the high mobility of birds with the need for occurrences of reasonable spatial scope. Note that a population's roost sites and foraging areas are parts of the same occurrence, even if they are more than 5 km apart.

For swallows and other species with similar behavioral ecology, the separation distance pertains to communal roost sites rather than to foraging areas; the former tend to be more stable and specific over time than the latter.

Date: 03Sep2004
Author: Hammerson, G.

Use Class: Nonmigratory
Minimum Criteria for an Occurrence: Occurrences are based on evidence of historical presence, or current and likely recurring presence, at a particular location. Such evidence minimally includes collection or reliable observation and documentation of one or more individuals in or near appropriate habitat.

These occurrence specifications are used for nonmigratory populations of passerine birds.

Separation Barriers: None.
Separation Distance for Unsuitable Habitat: 5 km
Separation Distance for Suitable Habitat: 5 km
Separation Justification: Significant dispersal and associated high potential for gene flow among populations of birds separated by tens of kilometers (e.g., Moore and Dolbeer 1989), and increasing evidence that individuals leave their usual home range to engage in extrapair copulations, as well as long foraging excursions of some species, make it difficult to circumscribe occurrences on the basis of meaningful population units without occurrences becoming too large. Hence, a moderate, standardized separation distance has been adopted for songbirds and flycatchers; it should yield occurrences that are not too spatially expansive while also accounting for the likelihood of gene flow among populations within a few kilometers of each other.

Be careful not to separate a population's nesting areas and breeding-season foraging areas as different occurrences; include them in the same occurrence even if they are more than 5 km apart. Blue jays have small summer home ranges but fly up to 4 kilometers to harvest mast (Tarvin and Woolfenden 1999). Flocks of pinyon jays range over 21-29 square kilometers (Ligon 1971, Balda and Bateman 1971); nesting and foraging areas may be widely separated. Tricolored blackbirds forage in flocks that range widely to more than 15 kilometers from the nesting colony (Beedy and Hamilton 1999).

Unsuitable habitat: Habitat not normally used for breeding/feeding by a particular species. For example, unsuitable habitat for grassland and shrubland birds includes forest/woodland, urban/suburban, and aquatic habitats. Most habitats would be suitable for birds with versatile foraging habits (e.g., most corvids).

Date: 10Sep2004
Author: Hammerson, G.
Notes: These specs pertain to nonmigratory species.
Population/Occurrence Viability
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U.S. Invasive Species Impact Rank (I-Rank) Not yet assessed
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Authors/Contributors
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NatureServe Conservation Status Factors Edition Date: 24Mar2009
NatureServe Conservation Status Factors Author: Hammerson, G.
Element Ecology & Life History Edition Date: 12Jan1996
Element Ecology & Life History Author(s): Hammerson, G.

Zoological data developed by NatureServe and its network of natural heritage programs (see Local Programs) and other contributors and cooperators (see Sources).

References
Help
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  • American Ornithologists' Union (AOU). Chesser, R.T., K.J. Burns, C. Cicero, J.L. Dunn, A.W. Kratter, I.J. Lovette, P.C. Rasmussen, J.V. Remsen, Jr., J.D. Rising, D.F. Stotz, and K. Winker. 2017. Fifty-eighth Supplement to the American Ornithologists' Union Check-list of North American Birds. The Auk 134:751-773.

  • Aquin, P. 1999. Évaluation de la situation des groupes taxonomiques des oiseaux du Québec. Ministère de l'Environnement et de la Faune. 13 pages.

  • B83COM01NAUS - Added from 2005 data exchange with Alberta, Canada.

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  • Benkman, C. W. 1993a. Logging, conifers, and the conservation of crossbills. Conservation Biology 7(3):473-479.

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  • Groth, J. G. 1993b. Evolutionary differentiation in morphology, vocalizations, and allozymes among nomadic sibling species in the North American red crossbill (LOXIA CURVIROSTRA) complex. Univ. California Publ. Zool. 127. 143 pp.

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  • Parks Canada. 2000. Vertebrate Species Database. Ecosystems Branch, 25 Eddy St., Hull, PQ, K1A 0M5.

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  • Rich, T. D., C. J. Beardmore, H. Berlanga, P. J. Blancher, M.S.W. Bradstreet, G. S. Butcher, D. W. Demarest, E. H. Dunn, W. C. Hunter, E. E. Iñigo-Elias, A. M. Martell, A. O. Panjabi, D. N. Pashley, K. V. Rosenberg, C. M. Rustay, J. S. Wendt, T. C. Will. 2004. Partners in Flight North American landbird conservation plan. Cornell Lab of Ornithology. Ithaca, NY. Online. Available:

  • See SERO listing

  • Terres, J. K. 1980. The Audubon Society encyclopedia of North American birds. Alfred A. Knopf, New York.

  • Zook, J. L. 2002. Distribution maps of the birds of Nicaragua, Costa Rica, and Panama. Unpublished.

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Citation for data on website including State Distribution, Watershed, and Reptile Range maps:
NatureServe. 2018. NatureServe Explorer: An online encyclopedia of life [web application]. Version 7.1. NatureServe, Arlington, Virginia. Available http://explorer.natureserve.org. (Accessed:

Citation for Bird Range Maps of North America:
Ridgely, R.S., T.F. Allnutt, T. Brooks, D.K. McNicol, D.W. Mehlman, B.E. Young, and J.R. Zook. 2003. Digital Distribution Maps of the Birds of the Western Hemisphere, version 1.0. NatureServe, Arlington, Virginia, USA.

Acknowledgement Statement for Bird Range Maps of North America:
"Data provided by NatureServe in collaboration with Robert Ridgely, James Zook, The Nature Conservancy - Migratory Bird Program, Conservation International - CABS, World Wildlife Fund - US, and Environment Canada - WILDSPACE."

Citation for Mammal Range Maps of North America:
Patterson, B.D., G. Ceballos, W. Sechrest, M.F. Tognelli, T. Brooks, L. Luna, P. Ortega, I. Salazar, and B.E. Young. 2003. Digital Distribution Maps of the Mammals of the Western Hemisphere, version 1.0. NatureServe, Arlington, Virginia, USA.

Acknowledgement Statement for Mammal Range Maps of North America:
"Data provided by NatureServe in collaboration with Bruce Patterson, Wes Sechrest, Marcelo Tognelli, Gerardo Ceballos, The Nature Conservancy-Migratory Bird Program, Conservation International-CABS, World Wildlife Fund-US, and Environment Canada-WILDSPACE."

Citation for Amphibian Range Maps of the Western Hemisphere:
IUCN, Conservation International, and NatureServe. 2004. Global Amphibian Assessment. IUCN, Conservation International, and NatureServe, Washington, DC and Arlington, Virginia, USA.

Acknowledgement Statement for Amphibian Range Maps of the Western Hemisphere:
"Data developed as part of the Global Amphibian Assessment and provided by IUCN-World Conservation Union, Conservation International and NatureServe."

NOTE: Full metadata for the Bird Range Maps of North America is available at:
http://www.natureserve.org/library/birdDistributionmapsmetadatav1.pdf.

Full metadata for the Mammal Range Maps of North America is available at:
http://www.natureserve.org/library/mammalsDistributionmetadatav1.pdf.

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