Medionidus walkeri - (Wright, 1897)
Suwannee Moccasinshell
Other English Common Names: Suwannee moccasinshell
Taxonomic Status: Accepted
Related ITIS Name(s): Medionidus walkeri (Wright, 1897) (TSN 80268)
Unique Identifier: ELEMENT_GLOBAL.2.115823
Element Code: IMBIV28060
Informal Taxonomy: Animals, Invertebrates - Mollusks - Freshwater Mussels
 
Kingdom Phylum Class Order Family Genus
Animalia Mollusca Bivalvia Unionoida Unionidae Medionidus
Genus Size: C - Small genus (6-20 species)
Check this box to expand all report sections:
Concept Reference
Help
Concept Reference: Turgeon, D.D., J.F. Quinn, Jr., A.E. Bogan, E.V. Coan, F.G. Hochberg, W.G. Lyons, P.M. Mikkelsen, R.J. Neves, C.F.E. Roper, G. Rosenberg, B. Roth, A. Scheltema, F.G. Thompson, M. Vecchione, and J.D. Williams. 1998. Common and scientific names of aquatic invertebrates from the United States and Canada: Mollusks. 2nd Edition. American Fisheries Society Special Publication 26, Bethesda, Maryland: 526 pp.
Concept Reference Code: B98TUR01EHUS
Name Used in Concept Reference: Medionidus walkeri
Taxonomic Comments: M. walkeri is regarded as distinct by the general scientific community, including Williams et al. (2014) and Johnson et al. (2016, in press). Clench and Turner (1956) recognized only one species of Medionidus from the Suwannee, Ochlockonee, and Apalachicola River systems. Their records of Medionidus penicillatus from the Ochlockonee River are now recognized as Medionidus simpsonianus, and their Suwannee River records are now recognized as Medionidus walkeri (Johnson, 1977).
Conservation Status
Help

NatureServe Status

Global Status: G1
Global Status Last Reviewed: 25Oct2016
Global Status Last Changed: 31Aug2000
Rounded Global Status: G1 - Critically Imperiled
Reasons: This species has a very limited distribution (part of one river system) and has experienced significantly population and range declines. Threats include deteriorating habitat and water quality in some portions of its range, as well as potential overcollecting in past.
Nation: United States
National Status: N1 (31Aug2000)

U.S. & Canada State/Province Status
United States Florida (S1)

Other Statuses

U.S. Endangered Species Act (USESA): LT: Listed threatened (07Nov2016)
IUCN Red List Category: CR - Critically endangered
American Fisheries Society Status: Threatened (01Jan1993)

NatureServe Global Conservation Status Factors

Range Extent: 100-250 square km (about 40-100 square miles)
Range Extent Comments: This species is currently endemic to the Suwannee River Basin in Florida and Georgia.  Historical range includes the lower and middle Suwannee River mainstem, and two large tributaries ? the Santa Fe River sub-basin and the lower Withlacoochee River mainstem (U.S. Fish and Wildlife Service 2016).  Recent records indicate a substantial decline, with present range being limited to the middle Suwannee River and lower Santa Fe River in Florida.  Surveys suggest that it has disappeared from the Withlacoochee River (last collected in 1969) and the upper Santa Fe River sub-basin, including the New River (last collected in 1996).  Williams et al. (2014) also reported the species? occurrence in the Hillsborough River in west-central Florida, Hillsborough County, based on a collection of mussels made in 1932 by T. H. Van Hyning.  Subsequent study strongly suggested that  these data represented a cataloguing error and that the species should be considered as endemic to the Suwannee River system (J. D. Williams, e-mail to D. R. Jackson, 30 October 2016).

 

Area of Occupancy: 6-125 4-km2 grid cells
Area of Occupancy Comments: Linear occupancy is 40-300 km.

Number of Occurrences: 1 - 5
Number of Occurrences Comments: This species is endemic to the Florida portion of the Suwannee River system, where it was known historically from 11 localities (four on the mainstem of the Suwannee River, one on the Withlacoochee River, five in the Santa Fe River, and one in the New River).  More recent surveys suggest that it has disappeared from the Withlacoochee River (last collected in 1969) and the upper Santa Fe River sub-basin, including the New River (last collected in 1996).  O'leno Sink is considered as a separation barrier within the Santa Fe River.

Population Size: 1 - 1000 individuals
Population Size Comments: This species is exceedingly rare and is in significant decline.  Surveys from 2013?2015 found only 74 live specimens, all but one of which were in the Suwannee River mainstem (only one in the lower Santa Fe River, and none in the Upper Santa Fe and Withlacoochee River sub-basins; U.S. Fish and Wildlife Service 2016).  Johnson (1977) noted that the species was abundant only at the type locality (Suwannee River, Ellaville, Madison County, Florida), but was uncommon at other sites. Of the 14 (11?) historical records located, only one contained >20 specimens. The last site to harbor large populations yielded only three specimens in two surveys during 1987. Only one live specimen was collected in the decade prior to 2010.

Number of Occurrences with Good Viability/Integrity: None to very few (0-3)
Viability/Integrity Comments: Only the population in the Suwannee River mainstem appears to be viable, and it is currently considered to be stable (U.S. Fish and Wildlife Service 2016).  All other populations are historical or severely depressed with low viability.

Overall Threat Impact: High
Overall Threat Impact Comments: Threats include sedimentation from agricultural and silvicultural activities; phosphate mining (upper Suwannee River mainstem); industrial pollution (pulp mill in the Withlacoochee watershed) and localized municipal pollution; watershed development; spate flows (e.g., sudden fast flows with high sediment loads) in the upper Santa Fe River; deadhead logging and large boat wakes; vehicular accidents involving transport of hazardous materials; and competition from Asiatic clams (Corbicula). Overharvest by shell collectors and biologists has been a distinct possibility; in the past 20 years, >20 specimens of this threatened species have been retained for collections at the GEXEMPSITE alone. Given already stressed populations throughout most or possibly all of its range, overcollecting can potentially contribute significantly to this species' decline.

Short-term Trend: Decline of >70%
Short-term Trend Comments: This species is exceedingly rare and is in significant decline.  Surveys from 2013?2015 found only 74 live specimens, all but one of which were in the Suwannee River mainstem (only one in the lower Santa Fe River, and none in the Upper Santa Fe and Withlacoochee River sub-basins; US Fish and Wildlife Service 2016).  Only one individual from a single site was collected in the decade prior to 2010, although multiple sites throughout the Suwannee River system have been surveyed for unionid mussels (J. Brim Box, pers. obs.).  The only remaining populations of significance, in the Suwannee River mainstem, appear to be stable as a result of streambed habitat stability and the attenuation of threats there.

Long-term Trend: Decline of >80%

Intrinsic Vulnerability: Highly to moderately vulnerable.
Intrinsic Vulnerability Comments: Freshwater mussels are inherently vulnerable to threats from siltation, pollution, eutrophication, channelization, impoundment, collection, drought and water withdrawal, competiton from invasive non-native mussels, and changes to larval host fish populations.  Apparent restriction of host fish species to darters, which have low vagility, limits repopulation of sites from which species has declined or disappeared.

Environmental Specificity: Very narrow to moderate.

Other NatureServe Conservation Status Information

Inventory Needs: Determine status of extant populations, re-survey historic sites, search for new localities by conducting intensive surveys in the Withlacochee and Suwannee mainstems and in their largest tributaries, including in Georgia, as well as in the lower Santa Fe River mainstem (below Santa Fe Sink); and inventory potential habitat for future reintroduction of cultured stock/transplants. Surveys in 2015 failed to find the species in the Withlacoochee sub-basin.

Protection Needs: Maintain high water and benthic habitat (substrate) qualities, as well as adequate flow regimes, throughout the Suwannee River system. This may be partially accomplished via establishment of buffers and streamside management zones for all agricultural, silvicultural, mining, and developmental activities; protection of floodplain forests and adjoining upland habitat is paramount. Best management practices to follow include employing forestry practices that cause minimal soil erosion; preventing access of livestock to natural surface waters and drains; situating roads at least 0.25 mi. (0.4 km) from heads of all tributaries, even more on steep slopes; using silt fencing and vegetation to control runoff and siltation at all stream crossings, especially during construction and maintenance; using and maintaining sewer systems rather than septic tanks and stream-dumping for management of wastewater; and avoiding use of agricultural pesticides on porous soils near streams. Prevent damming, dredging, and pollution throughout drainages, but especially near recorded sites. Remove existing dams if any, but with great care to limit downstream sedimentation. Limit withdrawal of surface and subterranean waters as necessary to maintain normal stream flows, especially during drought. Prevent or limit establishment of invasive species (including zebra mussel, Dreissena polymorpha) to the extent possible. Where appropriate, protect populations through acquisitions and easements over streamside lands by working with government agencies and conservation organizations. Management of the Apalachicola River system must address multiple threats, especially water withdrawal in the state of Georgia.
Consider addition to federal threatened species list.

Distribution
Help
Global Range: (100-250 square km (about 40-100 square miles)) This species is currently endemic to the Suwannee River Basin in Florida and Georgia.  Historical range includes the lower and middle Suwannee River mainstem, and two large tributaries ? the Santa Fe River sub-basin and the lower Withlacoochee River mainstem (U.S. Fish and Wildlife Service 2016).  Recent records indicate a substantial decline, with present range being limited to the middle Suwannee River and lower Santa Fe River in Florida.  Surveys suggest that it has disappeared from the Withlacoochee River (last collected in 1969) and the upper Santa Fe River sub-basin, including the New River (last collected in 1996).  Williams et al. (2014) also reported the species? occurrence in the Hillsborough River in west-central Florida, Hillsborough County, based on a collection of mussels made in 1932 by T. H. Van Hyning.  Subsequent study strongly suggested that  these data represented a cataloguing error and that the species should be considered as endemic to the Suwannee River system (J. D. Williams, e-mail to D. R. Jackson, 30 October 2016).

 

U.S. States and Canadian Provinces
Color legend for Distribution Map
Endemism: endemic to a single state or province

U.S. & Canada State/Province Distribution
United States FL

Range Map
No map available.


U.S. Distribution by County Help
State County Name (FIPS Code)
FL Alachua (12001), Bradford (12007), Columbia (12023)*, Dixie (12029)*, Gilchrist (12041)*, Hamilton (12047)*, Lafayette (12067)*, Levy (12075)*, Madison (12079)*, Suwannee (12121)*, Union (12125)
* Extirpated/possibly extirpated
U.S. Distribution by Watershed Help
Watershed Region Help Watershed Name (Watershed Code)
03 withlacoochee (03110203)+*, Lower Suwannee (03110205)+*, Santa Fe (03110206)+
+ Natural heritage record(s) exist for this watershed
* Extirpated/possibly extirpated
Ecology & Life History
Help
Basic Description: A small, highly sculptured, dark freshwater mussel.
General Description: See Johnson (1977) and Deyrup and Franz (1994).
Diagnostic Characteristics: Rhomboidal outline, dark, generally rayless shell, sharply pointed ventral posterior ridge, with a few coarse plications posteriorly.
Reproduction Comments: This species is probably bradytictic (long-term brooder), as is its northern congener, Medionidus conradicus. The glochidial host is not known.
Ecology Comments: Like its Florida congeners, an inhabitant of channels of high quality streams.
Habitat Type: Freshwater
Non-Migrant: N
Locally Migrant: N
Long Distance Migrant: N
Mobility and Migration Comments: Greatest potential during glochidial stage on fish. Adults are essentially sessile however some passive movement downstream may occur during high flows.
Riverine Habitat(s): BIG RIVER, CREEK, Low gradient, MEDIUM RIVER, Riffle
Special Habitat Factors: Benthic
Habitat Comments: It has been reported from mud and sand in slight to moderate current (Heard, 1979; Johnson, 1977), and in medium-sized creeks and rivers in muddy sand, sand and gravel, in slow to moderate current (Deyrup and Franz, 1994). Like most members of the genus, it is most often found in mid-channel habitats in coarser sediments (J. Brim Box, pers. obs.).
Adult Food Habits: Detritivore
Immature Food Habits: Parasitic
Food Comments: Presumably fine particulate organic matter, primarily detritus, and/or zooplankton, and/or phytoplankton (Fuller, 1974). Larvae (glochidia) of freshwater mussels are generally parasitic on fish and there may be a specificity among some species.
Length: 4.6 centimeters
Economic Attributes Not yet assessed
Help
Management Summary
Help
Biological Research Needs: Determine life history, reproductive biology, fecundity, viability of extant populations and microhabitat requirements; develop propagation techniques; identify any additional host fish (currently known: two species of darters, Percina nigrofasciata and Etheostoma edwini), its requirements, and population status; determine its sensitivity to silt, excessive nutrients, and pollutants; conduct competitive interaction studies with Corbicula, and develop control methodologies for the latter.
Population/Occurrence Delineation
Help
Group Name: Freshwater Mussels

Use Class: Not applicable
Minimum Criteria for an Occurrence: Occurrences are based on some evidence of historical or current presence of single or multiple specimens, including live specimens or recently dead shells (i.e., soft tissue still attached and/or nacre still glossy and iridescent without signs of external weathering or staining), at a given location with potentially recurring existence. Weathered shells constitute a historic occurrence. Evidence is derived from reliable published observation or collection data; unpublished, though documented (i.e. government or agency reports, web sites, etc.) observation or collection data; or museum specimen information.
Mapping Guidance: Based on the separation distances outlined herein, for freshwater mussels in STANDING WATER (or backwater areas of flowing water such as oxbows and sloughs), all standing water bodies with either (1) greater than 2 km linear distance of unsuitable habitat between (i.e. lotic connections), or (2) more than 10 km of apparently unoccupied though suitable habitat (including lentic shoreline, linear distance across water bodies, and lentic water bodies with proper lotic connections), are considered separate element occurrences. Only the largest standing water bodies (with 20 km linear shoreline or greater) may have greater than one element occurrence within each. Multiple collection or observation locations in one lake, for example, would only constitute multiple occurrences in the largest lakes, and only then if there was some likelihood that unsurveyed areas between collections did not contain the element.

For freshwater mussels in FLOWING WATER conditions, occurrences are separated by a distance of more than 2 stream km of unsuitable habitat, or a distance of more than 10 stream km of apparently unoccupied though suitable habitat. Standing water between occurrences is considered suitable habitat when calculating separation distance for flowing water mussel species unless dispersal barriers (see Separation Barriers) are in place.

Several mussel species in North America occur in both standing and flowing water (see Specs Notes). Calculation of separation distance and determination of separation barriers for these taxa should take into account the environment in which the element was collected. Juvenile mussels do not follow this pattern and juveniles are typically missed by most standard sampling methods (Hastie and Cosgrove, 2002; Neves and Widlak, 1987), therefore juvenile movement is not considered when calculating separation distance.

Separation Barriers: Separation barriers within standing water bodies are based solely on separation distance (see Separation Distance-suitable, below). Separation barriers between standing water bodies and within flowing water systems include lack of lotic connections, natural barriers such as upland habitat, absence of appropriate species specific fish hosts, water depth greater than 10 meters (Cvancara, 1972; Moyle and Bacon, 1969) or anthropogenic barriers to water flow such as dams or other impoundments and high waterfalls.
Separation Distance for Unsuitable Habitat: 2 km
Separation Distance for Suitable Habitat: 10 km
Alternate Separation Procedure: None
Separation Justification: Adult freshwater mussels are largely sedentary spending their entire lives very near to the place where they first successfully settled (Coker et al., 1921; Watters, 1992). Strayer (1999) demonstrated in field trials that mussels in streams occur chiefly in flow refuges, or relatively stable areas that displayed little movement of particles during flood events. Flow refuges conceivably allow relatively immobile mussels to remain in the same general location throughout their entire lives. Movement occurs with the impetus of some stimulus (nearby water disturbance, physical removal from the water such as during collection, exposure conditions during low water, seasonal temperature change or associated diurnal cycles) and during spawning. Movement is confined to either vertical movement burrowing deeper into sediments though rarely completely beneath the surface, or horizontal movement in a distinct path often away from the area of stimulus. Vertical movement is generally seasonal with rapid descent into the sediment in autumn and gradual reappearance at the surface during spring (Amyot and Downing, 1991; 1997). Horizontal movement is generally on the order of a few meters at most and is associated with day length and during times of spawning (Amyot and Downing, 1997). Such locomotion plays little, if any, part in the distribution of freshwater mussels as these limited movements are not dispersal mechanisms. Dispersal patterns are largely speculative but have been attributed to stream size and surface geology (Strayer, 1983; Strayer and Ralley, 1993; van der Schalie, 1938), utilization of flow refuges during flood stages (Strayer, 1999), and patterns of host fish distribution during spawning periods (Haag and Warren, 1998; Watters, 1992). Lee and DeAngelis (1997) modeled the dispersal of freshwater into unoccupied habitats as a traveling wave front with a velocity ranging from 0.87 to 2.47 km/year (depending on mussel life span) with increase in glochidial attachment rate to fish having no effect on wave velocity.

Nearly all mussels require a host or hosts during the parasitic larval portion of their life cycle. Hosts are usually fish, but a few exceptional species utilize amphibians as hosts (Van Snik Gray et al., 2002; Howard, 1915) or may metamorphose without a host (Allen, 1924; Barfield et al., 1998; Lefevre and Curtis, 1911; 1912). Haag and Warren (1998) found that densities of host generalist mussels (using a variety of hosts from many different families) and displaying host specialists (using a small number of hosts usually in the same family but mussel females have behavioral modifications to attract hosts to the gravid female) were independent of the densities of their hosts. Densities of non-displaying host specialist mussels (using a small number of hosts usually in the same family but without host-attracting behavior) were correlated positively with densities of their hosts. Upstream dispersal of host fish for non-displaying host specialist mussels could, theoretically, transport mussel larvae (glochidia) over long distances through unsuitable habitat, but it is unlikely that this occurs very often. D. Strayer (personal communication) suggested a distance of at least 10 km, but a greater distance between occurrences may be necessary to constitute genetic separation of populations. As such, separation distance is based on a set, though arbitrary, distance between two known points of occurrence.

Date: 18Oct2004
Author: Cordeiro, J.
Notes: Contact Jay Cordeiro (jay_cordeiro@natureserve.org) for a complete list of freshwater mussel taxa sorted by flow regime.
Population/Occurrence Viability
Help
Justification: Use the Generic Element Occurrence Rank Specifications (2008).
Key for Ranking Species Element Occurrences Using the Generic Approach (2008).
U.S. Invasive Species Impact Rank (I-Rank) Not yet assessed
Help
Authors/Contributors
Help
NatureServe Conservation Status Factors Edition Date: 25Oct2016
NatureServe Conservation Status Factors Author: Jackson, D. R. (2016); Cordeiro, J. (2011); Butler, R.S. [1992 edition]; Brim Box, J., and C.' (2000)
Element Ecology & Life History Edition Date: 25Nov2011
Element Ecology & Life History Author(s): Cordeiro, J. (2011); BUTLER, R.S. (2000)

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

References
Help
  • Burch, J.B. 1975c. Freshwater Unionacean Clams (Mollusca: Pelecypoda) of North America: Biota of Freshwater Ecosystems, Identification Manual No 11. Environmental Protection Agency, Washington, D.C. 176 pp.

  • Clench, W.J. and R.D. Turner. 1956. Freshwater mollusks of Alabama, Georgia, and Florida from the Escambia to the Suwanee River. Bulletin of the Florida State Museum Biological Sciences, 1(3): 97-239.

  • Deyrup, M. and R. Franz. 1994. Rare and Endangered Biota of Florida, Volume IV. Invertebrates. University Press of Florida: Gainesville, Florida. 798 pp.

  • Fuller, S.L.H. 1974. Chapter 8: Clams and mussels (Mollusca: Bivalvia). Pages 215-273 in: C.W. Hart, Jr. and S.L.H. Fuller (eds.) Pollution Ecology of Freshwater Invertebrates. Academic Press: New York. 389 pp.

  • Heard, W.H. 1979. Identification manual of the fresh water clams of Florida. State of Florida, Department of Environmental Regulation, Technical Series, 4(2): 1-82.

  • Howard, A.D. 1915. Some exceptional cases of breeding among the Unionidae. The Nautilus 29:4-11.

  • Johnson, R.I. 1970a. The systematics and zoogeography of the Unionidae (Mollusca: Bivalvia) of the southern Atlantic slope region. Bulletin of the Museum of Comparative Zoology, Harvard University 140(6): 263-449.

  • Johnson, R.I. 1972a. The Unionidae (Mollusca: Bivalvia) of peninsular Florida. Bulletin of the Florida State Museum of Biological Science 16(4): 181-249.

  • Johnson, R.I. 1977. Monograph of the genus Medionidus (Bivalvia: Unionidae) mostly from the Apalachicolan region, southeastern United States. Occasional Papers on Mollusks, 4(56): 161-187.

  • Lefevre, G. and W.T. Curtis. 1912. Studies on the reproduction and artificial propogation of fresh-water mussels. Bulletin of the Bureau of Fisheries 30:102-201.

  • Moyle, P. and J. Bacon. 1969. Distribution and abundance of molluscs in a fresh water environment. Journal of the Minnesota Academy of Science 35(2/3):82-85.

  • Strayer, D. 1983. The effects of surface geology and stream size on freshwater mussel (Bivalvia, Unionidae) distribution in southeastern Michigan, U.S.A. Freshwater Biology 13:253-264.

  • Strayer, D.L. 1999a. Use of flow refuges by unionid mussels in rivers. Journal of the North American Benthological Society 18(4):468-476.

  • Strayer, D.L. and J. Ralley. 1993. Microhabitat use by an assemblage of stream-dwelling unionaceans (Bivalvia) including two rare species of Alasmidonta. Journal of the North American Benthological Society 12(3):247-258.

  • Turgeon, D.D., A.E. Bogan, E.V. Coan, W.K. Emerson, W.G. Lyons, W.L. Pratt, C.F.E. Roper, A. Scheltema, F.G. Thompson, and J.D. Williams. 1988. Common and scientific names of aquatic invertebrates from the United States and Canada: mollusks. American Fisheries Society Special Publication 16: viii + 277 pp., 12 pls.

  • Turgeon, D.D., J.F. Quinn, Jr., A.E. Bogan, E.V. Coan, F.G. Hochberg, W.G. Lyons, P.M. Mikkelsen, R.J. Neves, C.F.E. Roper, G. Rosenberg, B. Roth, A. Scheltema, F.G. Thompson, M. Vecchione, and J.D. Williams. 1998. Common and scientific names of aquatic invertebrates from the United States and Canada: Mollusks. 2nd Edition. American Fisheries Society Special Publication 26, Bethesda, Maryland: 526 pp.

  • U.S. Fish and Wildlife Service.  2016.  Endangered and threatened wildlife and plants; threatened species status for Suwannee Moccasinshell.  Federal Register 81(100):32664 -32678.

  • Van der Schalie, H. 1938a. The naiad fauna of the Huron River in southeastern Michigan. Miscellaneous Publication of the Museum of Zoology, University of Michigan 40:7-78.

  • Watters, G.T. 1992a. Unionids, fishes, and the species-area curve. Journal of Biogeography 19:481-490.

  • Williams, J. D., R. S. Butler, G. L. Warren, and N. A. Johnson.  2014a.  Freshwater Mussels of Florida.  University of Alabama Press, Tuscaloosa, Alabama. 498 pp.

  • Williams, J.D., M.L. Warren, Jr., K.S. Cummings, J.L. Harris, and R.J. Neves. 1993b. Conservation status of freshwater mussels of the United States and Canada. Fisheries 18(9): 6-22.

  • van der Schalie, H. 1940. The naiad fauna of the Chipola River in northwestern Florida. Lloydia 3(3):191-208.

Use Guidelines & Citation

Use Guidelines and Citation

The Small Print: Trademark, Copyright, Citation Guidelines, Restrictions on Use, and Information Disclaimer.

Note: All species and ecological community data presented in NatureServe Explorer at http://explorer.natureserve.org were updated to be current with NatureServe's central databases as of November 2016.
Note: This report was printed on

Trademark Notice: "NatureServe", NatureServe Explorer, The NatureServe logo, and all other names of NatureServe programs referenced herein are trademarks of NatureServe. Any other product or company names mentioned herein are the trademarks of their respective owners.

Copyright Notice: Copyright © 2017 NatureServe, 4600 N. Fairfax Dr., 7th Floor, Arlington Virginia 22203, U.S.A. All Rights Reserved. Each document delivered from this server or web site may contain other proprietary notices and copyright information relating to that document. The following citation should be used in any published materials which reference the web site.

Citation for data on website including State Distribution, Watershed, and Reptile Range maps:
NatureServe. 2017. 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.

Restrictions on Use: Permission to use, copy and distribute documents delivered from this server is hereby granted under the following conditions:
  1. The above copyright notice must appear in all copies;
  2. Any use of the documents available from this server must be for informational purposes only and in no instance for commercial purposes;
  3. Some data may be downloaded to files and altered in format for analytical purposes, however the data should still be referenced using the citation above;
  4. No graphics available from this server can be used, copied or distributed separate from the accompanying text. Any rights not expressly granted herein are reserved by NatureServe. Nothing contained herein shall be construed as conferring by implication, estoppel, or otherwise any license or right under any trademark of NatureServe. No trademark owned by NatureServe may be used in advertising or promotion pertaining to the distribution of documents delivered from this server without specific advance permission from NatureServe. Except as expressly provided above, nothing contained herein shall be construed as conferring any license or right under any NatureServe copyright.
Information Warranty Disclaimer: All documents and related graphics provided by this server and any other documents which are referenced by or linked to this server are provided "as is" without warranty as to the currentness, completeness, or accuracy of any specific data. NatureServe hereby disclaims all warranties and conditions with regard to any documents provided by this server or any other documents which are referenced by or linked to this server, including but not limited to all implied warranties and conditions of merchantibility, fitness for a particular purpose, and non-infringement. NatureServe makes no representations about the suitability of the information delivered from this server or any other documents that are referenced to or linked to this server. In no event shall NatureServe be liable for any special, indirect, incidental, consequential damages, or for damages of any kind arising out of or in connection with the use or performance of information contained in any documents provided by this server or in any other documents which are referenced by or linked to this server, under any theory of liability used. NatureServe may update or make changes to the documents provided by this server at any time without notice; however, NatureServe makes no commitment to update the information contained herein. Since the data in the central databases are continually being updated, it is advisable to refresh data retrieved at least once a year after its receipt. The data provided is for planning, assessment, and informational purposes. Site specific projects or activities should be reviewed for potential environmental impacts with appropriate regulatory agencies. If ground-disturbing activities are proposed on a site, the appropriate state natural heritage program(s) or conservation data center can be contacted for a site-specific review of the project area (see Visit Local Programs).

Feedback Request: NatureServe encourages users to let us know of any errors or significant omissions that you find in the data through (see Contact Us). Your comments will be very valuable in improving the overall quality of our databases for the benefit of all users.