Biodiversity Guide - The Intertwine

egional conservation strategybiodiversity guideChapter 5 Fish and Wildlife of the RegionThe Oak Woodland Bird Conservation Plan: AStrategy for Protecting and Managing Oak WoodlandHabitats and Associated Birds in California.California Partners in Flight. Version 2.0.S. Zack. 2002. Point Reyes Bird Observatory,Stinson Beach, CA. http://www.prbo.org/calpif/plans.htmlThe Oregon Conservation StrategyOregon Department of Fish and Wildlife. 2006.Oregon Department of Fish and Wildlife, Salem,Oregon.www.dfw.state.or.usThe Willamette Valley Landowner’s Guide toCreating Habitat for Grassland BirdsOregon Department of Fish and Wildlife.Portland, Oregon’s Bird AgendaCity of Portland, Bureau of EnvironmentalServices and Portland Parks and Recreation. June27, 2011. Available at http://www.portlandonline.com/bes/index.cfm?a=354681&c=55194Rainforest Birds: A Land Manager’s Guide toBreeding Bird Habitat in Young Conifer Forests inthe Pacific NorthwestB. Altman and J. Hagar. 2006. USGS ScientificInvestigations Report 2006-5304, prepared incooperation with the American Bird Conservancy.Available at http://pubs.usgs.gov/sir/2006/5304/.Willamette Valley Focus Area PlanOregon Habitat Joint Venture. August 2004.Bird Friendly Building GuidelinesAudubon Society of Portland. 2012.Metro’s bird, mammal, and amphibian/reptilewildlife checklists for the Portland areahttp://www.oregonmetro.gov/index.cfm/go/by.web/id=15421MammalsSusan Barnes and Liz Ruther, Oregon Departmentof Fish and Wildlife, and Jeff Azerrad, WashingtonDepartment of Wildlifenon-natives, occur within the greater Portland-Vancouver region. Mammals are extremelydiverse and are present at every level of the foodweb as herbivores, granivores, insectivores,omnivores, and carnivores. Habitat quality andquantity are the main predictors of mammal speciesdiversity. Mammals typically are divided intoseven subgroups:n Rodentsn Rabbits, hares, and pikasn Batsn Shrews and molesn Ungulates (i.e., hoofed mammals)n Omnivoresn CarnivoresSmall and medium-sized mammals, especiallythose that eat grain, are the most abundantmammals in urban and suburban environments.Suburban residential areas often make excellenthabitat for medium-sized omnivores, such asraccoons and skunks. In general, urban environmentssupport fewer species of mammals than dosurrounding rural and undeveloped areas. Thespecies that occur in urbanized environmentstend to be habitat generalists rather than specialists.Urbanized areas can support high populationsof non-native mammal species such as thehouse mouse, Norway rat, Virginia opossum, andeastern fox squirrel. In less urbanized areas wherelarger patches of intact habitat remain, a greatervariety of species is likely to be encountered.Mammals play a variety of ecosystem roles.Predatory mammals regulate herbivores (i.e.,plant-eating animals) populations; this in turnaffects grazing patterns and influences thedevelopment and quality of vegetation and thuswildlife habitat. For example, cougar limit deerand elk populations, thereby reducing habitatovergrazing. Another example of mammals asregulators is the relationship between bat andinsect populations. Bats in Oregon and Washingtonconsume only insects, with an adult bat eatingabout 1,000 insectsper hour. Bats also area source of naturalfertilizer (guano) thatis important to ecosystemhealth. Mammalssuch as squirrelsand chipmunks playan important role inhabitat regeneration bydispersing seeds. Mammalsprovide stabilityto entire food webs andlife cycles, althoughthese functions oftenare disrupted by humanactions.Some mammals areconsidered keystone species, meaning that theirrole in the ecosystem has a ripple effect on everyspecies below them, as well as on the ecosystemwithin which they live. Pocket gophers are anexample of a keystone species. Pocket gopherslive in grasslands and create extensive tunnelsystems, thus aerating the soil (which promotesplant health), creating burrows for other species,and creating areas of bare earth that are used byother species, including birds, insects, and reptiles.Another keystone species is the Americanbeaver, which often is referred to as an “ecosystemengineer” because it creates extensive wetlandcomplexes through its dam-building activities.Beaver-created wetland habitats provide a mosaicof water/land interfaces, resulting in greater plantand animal diversity than would otherwise bepresent. There is increasing evidence that beaversplay a critical role in overall ecosystem health andinfluence water quality and quantity, plant regeneration,and fish and wildlife production.Mammals such as raccoons, coyotes, andeastern fox squirrels are habitat generalists, whileothers, such as the gray fox, western gray squirrel,and Douglas squirrel, are habitat specialists.Generalists are more adaptable to fragmentedhabitats, while specialists typically require larger,more intact habitats or specific habitat types andConservation Issues and Key Threats to MammalsConservation of mammal species diversity isa concern locally, regionally, and globally. Allmammals face a variety of threats, although somethreats are more obvious than others. Rare specieswhose distribution naturally is limited are mostsusceptible to environmental degradation andat greatest risk of extinction or local or regionalextirpation. Small mammals are just as likely tobecome extinct as larger species, but ungulates(i.e., hoofed mammals) and large carnivoresreceive disproportionate attention with respect toconservation activity and research. Many of thesesmaller mammal species are classified as nongamewildlife. Nongame species generally receiveless conservation attention, primarily becausefederal and state fish and wildlife managementagencies traditionally have been structured andfunded based on fish and game species.The majority of mammal species in the greaterPortland-Vancouver region receive some levelof protection by federal and/or state wildlifemanagement agencies. In Oregon, some fall intothe category of non-protected nongame wildlife(OAR 635-044-0132) and therefore are notprotected from take (i.e., being killed or removedfrom the wild). In Washington, nongame speciesOregon has at least 122 mammal species andWashington has 111, not including marine mammals.At least 76 mammal species, including eightare less tolerant of urbanization and human102presence.103