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Southwestern Golf Cou rses OfferNeeded Riparian Habitat for BirdsA comparison of golf courses with natural areas underscoresthe importance of golf courses as bird habitat.BY MICHELE MEROLA-ZWARTJES AND JOHN P. DELONG

This pond at the UNM Championship Course demonstrates how golf courses may provide habitatsthat are very similar in structure and composition to natural riparian habitats. Cottonwoods, willows,and cattails surround the water, providing habitat for a variety of bird species, including red-wingedblackbirds, black-crowned night herons, warbling vireos, yellow warblers, and western tanagers. Thirty-four species of birds were detected on this course, and 21 of these were riparian-associate speciesthat were not found on the paired reference site.

MOStstudies of birds in urbanareas have reported a decreasein avian species richness and/or

diversity in association with urbaniza-tion, although density typicallyincreases. In the southwestern UnitedStates, the greatest diversity of breedingbirds is normally found in riparianhabitats (areas surrounding rivers orlakes). It is estimated that the birddiversity in riparian zones surpasses thatof all other western habitat typescombined.

In a region characterized by lowrainfall and often sparse vegetation,riparian zones act as an oasis for bothmigratory and resident birds, offering arelative abundance of the criticalelements of water, food, and cover.Natural riparian systems are quicklydisappearing, however, in response tothe demands of a growing humanpopulation on these areas for water,recreation, and development, as well asdegradation due to factors such as floodcontrol efforts and improper grazingpractices. Estimates are that up to 95%of western riparian habitats have beenlost or degraded over the past century,and many of the bird species associatedwith these systems have been drivenout or have experienced severe declines.

SOUTHWESTERNGOLF COURSESMost golf courses in the Southwestprovide a combination of habitatcharacteristics that are reminiscent ofthe riparian systems used by western

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birds. They often have permanent watersources, used as either water hazards, forirrigation, or both. They have deciduoustrees that provide cover, shade, nest sites,and food. Depending upon the extent,composition, and structure of the vege-tation in out-of-play areas, golf coursesmay potentially offer rewarding foragingand/or nesting habitat for birds thatutilize shrub habitats as well as thosethat forage on the turf or in the canopy.

Given the extensive loss of ripariansystems throughout the West and thepotential similarity of habitats on golfcourses to those of riparian areas, we

were interested in determining whethergolf courses might possibly serve assurrogate riparian habitats for breedingbirds in the Southwest. We hypothesizedthat golf courses in the Southwestwould not only have greater avianspecies richness and abundance whencompared to the surrounding naturalenvironment, but that the golf courseswould also support a greater number ofbird species normally associated withriparian areas. The goals of our studywere to determine: (1) how the presenceof a golf course impacts the native birdcommunity through comparisons of

Pied-billed grebe. Photo by Dennis Larson, courtesy U.S. Fish and Wildlife Service.

abundance, species richness, diversity,evenness, and productivity between fivegolf courses and five undisturbed refer-ence areas assumed to represent theoriginal bird communities; (2) whethergolf courses support high numbers oftypically riparian bird species; and (3) ifpossible, identify those features of golfcourses that are most conducive tosupporting high numbers of nativeand riparian bird species.

STUDY SITESOur study sites were five golf coursesand five paired reference sites in thehigh desert region of Albuquerque,New Mexico. Courses were chosen torepresent a range of vegetation types,course features (e.g., water sources), andlandscape settings. The participatinggolf courses were the AlbuquerqueCountry Club (ACC), Four HillsCountry Club (FH), Paradise Hills GolfClub (PH), PaaKo Ridge Golf Club(PK), and University of New MexicoChampionship Course (UNM).

A paired reference site was selectedfor each golf course. Reference siteswere nearby natural areas that reflected,as much as possible, the habitat condi-tions that would have been presentprior to the construction of the com-panion course. The purpose of thesereference sites was to provide an aviancommunity baseline. Birds on thereference sites were assumed to repre-sent the original bird community for itspaired golf course.

RESULTS OF THETWO-YEAR STUDYGolf courses supported a greater num-ber of birds than surrounding naturalareas, a response that is commonthroughout studies of avian responses tourbanization. In contrast to many suchstudies, we also found increased avianspecies richness on most of the golfcourses, as well as increased diversity.The increase in avian abundance ongolf courses was to a large degree atthe expense of more specialized nativebird species, as has been witnessed in

numerous other studies of urbanizationeffects. We found that a relatively fewwidespread and abundant species madeup the majority of individuals detected(including, but not limited to, housesparrows, house finches, commongrackles, and European starlings), com-prising from 69% to 76% of the indi-viduals detected on three out of thefive courses.

Although they had fewer species, thereference sites were composed primarilyof native bird species, and these com-

munities were more even in their dis-tributions. The PaaKo Ridge golf coursewas exceptional in several aspects, as itdemonstrated greater species richnessand diversity, and similar evenness, whencompared to its natural area referencesite, and it was the only course that didnot have significantly fewer nativeindividuals.

Species richness of native birds wasgreater on golf courses, in contrast tothe results of many other studies ofbirds in urban environments. This resultheld across all five of the courses westudied. The abundance of these nativebirds was not as great as that of cosmo-politan or introduced species, but golfcourses supported numerous native bird

species that were not components ofthe avian community in the surround-ing natural areas. Of birds that wereexclusive to our golf course observa-tions, 54 (83%) were native species thatwe did not consider to be cosmopolitanor introduced species.

Furthermore, we found strong sup-port for our hypothesis that golf courseswould provide habitat for riparian birds.More than 70% of the species observedexclusively on golf courses were riparianassociates. The numbers of individuals

in this group were relatively low, par-ticularly once we excluded those thatare also considered cosmopolitan species(e.g., American robin). Still, 25% of thebirds observed on golf courses wereriparian associate species that were notrepresented in our samples of the sur-rounding natural area bird communities.

Our results add support to thehypothesis that avian species richnessand/or diversity does not respond tourbanization in a linear fashion, butinstead peaks at a level of intermediatedisturbance or development. At thehigher levels of urbanization, most ofthe land area is dominated by buildingsor paved areas, and any vegetation isprimarily ornamental. Golf courses,

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The ponds on the desert golf courses attracted birds such as this black-crowned night heron. Photo byLee Karney, courtesy U.S. Fish and Wildlife Service.

however, represent an intermediate levelof development in which most of theland area is still vegetated, some areas ofnative habitat may remain, and trees andponds are common. Habitat diversitymay actually increase under such ascenario, as structural diversity is addedthrough changes in vegetation as well asthe introduction of buildings and otherstructures that may serve as nest sites orperch sites, and openings are created foredge species. Moderate levels of devel-opment may increase food resources for

some guilds of birds. Scavenging oppor-tunities increase, and areas of lawn orturf are capable of supporting highnumbers of ground-foraging birds.

GOLF COURSE OASES INTHE DESERT LANDSCAPEThis potential increase in habitatdiversity at low to moderate levels ofdevelopment is particularly noticeablein the desert landscape. In general, thereis a strong positive correlation betweenbird species diversity and habitat diver-sity such that any increase in habitatdiversity, particularly in a relativelysimple landscape such as a desert, islikely to result in increased species rich-ness. The features added to the landscapeduring the development of a golf course ,often stand in sharp contrast to those ofthe desert environment. Courses may

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provide numerous shade trees, watersources, turf, structures, and vegetationtypes that are not available in the sur-rounding natural areas.

Riparian-like habitats surroundingponds on the UNM ChampionshipCourse offer tall broad-leaved trees,multiple understory vegetation layers,and abundant water with emergentvegetation - all features that are absentfrom the desert habitat in the immediatearea. In conjunction with numerousout-of-play areas dominated by remnant

native shrublands and expansive openareas of turf, this golf course collectivelyprovides a range of habitats that sup-ports a wide variety of birds, includingsuch diverse species as yellow warblers,spotted sandpipers, greater roadrunners(Geococcyx californianus), ash-throatedflycatchers, northern rough-wingedswallows, and American robins. Giventhis diversity of habitat types, it is hardlysurprising that the UNM course had agreater number of species, includinggreater numbers of native species, thanits comparison reference site. This con-trast in habitat diversity associated withgreater species richness was also apparentat the golf courses at Four Hills,Paradise Hills, and PaaKo.

The impact of a golf course on aviancommunity composition in the desertenvironment appears to be very differ-

ent from that of one that may be con-structed, for example, in a forested area.In other studies, increased developmentin hardwood forests led to a loss ofcanopy-foraging or bark-gleaning birds,since canopy trees were lost from thehabitat. This is consistent with theobservation that the loss of bird diver-sity is likely when development occursin an area that had an initially highdiversity of habitats.

By contrast, the addition of a golfcourse actually added this componentof habitat diversity (high canopy trees)at three out of five of our study sites(Four Hills, Paradise Hills, and UNM),thereby attracting canopy species orbark-gleaners that would not otherwisebe present in the avian community.Several of the species that decreased inresponse to urbanization in these otherstudies (1,2) were species that wedetected exclusively on the golf coursesin our study, including northern flickers,white-breasted nuthatches, downywoodpeckers, cliff swallows, and west-ern wood-pewees. The only course westudied that had less habitat complexityand structural diversity than its referencesite, the Albuquerque Country Club,was also the only course that had lowerbird abundance, species richness, anddiversity. Our study suggests that in thestructurally simple desert landscape, theadditional resources and habitat com-plexity provided by golf courses resultin increased avian abundance and

The western tanager was one of the nativespecies observed on several golf courses, butnot on any of the paired reference sites in thisstudy. Photo by Gary Kramer, courtesy U.S. Fishand Wildlife Service.

The relatively simple habitat structure of the reference site for the UNM Championship Course canbe deduced from this photograph. This undeveloped natural area, located directly across from the golfcourse, offers less for many bird species in terms of habitat diversity, complexity, and resources, whichis reflected in lower overall species richness (16 species). However, this site did support some of thedesert specialist species that were not detected on any of the golf courses in our study, includingscaled quail and burrowing owls.

species richness, including increasednative species richness.

ECO-FRIENDLYCHARACTERISTICSOF PAAKO RIDGECertain characteristics of the PaaKoRidge golf course deserve attention, asthis course was exceptional in both theabundance and diversity of native birdspecies. PaaKo is what has been termeda "naturalistic" golf course, one thatretains "the native vegetation, landform, soils, and typical habitat units of aregion." The course at PaaKo is basedupon the natural topography of theSandia foothills, turf is minimized, andthe out-of-play areas are indistinguish-able from the surrounding pinyon-juniper woodlands. PaaKo was the onlycourse that had greater abundance,species richness, diversity, and com-parable evenness of native species withits reference site; 76% of the individualsobserVed at this course were nativespecies. No native species were excludedfrom the PaaKo course, and 27 specieswere added to the community. PaaKowas also the only course where nativecavity-nesters used the nest boxes, andthe productivity at the golf course wascomparable to that of the comparisonnatural areas.

In addition to increased habitatdiversity, the greater native species rich-ness at PaaKo, and the continued domi-nance of its avian community by nativespecies is likely attributable to theextensive areas of undisturbed nativevegetation on the course. Increasednumbers of native bird species and theability to exclude invasive avian speciesare associated with the amount ofnative vegetation present.

WHATWE LEARNEDGolf courses in the high desert areaof Albuquerque have the potential tosupport large numbers of native birdspecies. In addition, the resources andhabitat diversity provided on thesecourses may mitigate, to some extent,the loss of riparian systems in the

Southwest. However, the conservationvalue of golf course habitats in thisdesert region could be improved tosupport greater numbers of native birdsand exclude more invasive exotics orpest species by increasing the complexvertical structure and diversity of plantspecies composition in the out-of-playareas on the courses, and, in particular,by increasing the extent and usage ofnative plants. Such improvements, evenon a very small, localized scale, have thepotential to effect changes in birdspecies composition, and golf coursesthat are dominated by native vegetationmay support significant numbers ofnative bird species.

Our data showing increased speciesrichness of native birds, and particularlyhigh numbers of riparian species onthese courses, demonstrate that thesegolf courses may be capable of provid-ing valuable stopover habitat for thenumerous species of migratory birdsthat utilize riparian corridors in theSouthwest. The potential for desert golf

courses to serve as surrogate riparianareas for these species has importantconservation implications, as manymigratory birds in the western U.S. arecurrently experiencing populationdeclines associated with the loss ofriparian habitats.

Editor's Note: For a more completereport of this research, including com-parative tables of observed bird species,methodology, and graphs of the results,visit the USGA's Turfgrass and Environ-mental Research Online at http://usga-tero.msu.edu/v04/n14.pdf TEROpublishes the results of studies fundedthrough USGA's Turfgrass andEnvironmental Research Program.

MICHELE MEROLA-ZWART]ES, PH.D.,

and JOHN P. DELONG, PH.D., USDAForest Service,Rocky Mountain ResearchStation, 333 Broadway SE, Suite 115,Albuquerque, NM.

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