View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by DigitalCommons@University of Nebraska University of Nebraska - Lincoln DigitalCommons@University of Nebraska - Lincoln The Prairie Naturalist Great Plains Natural Science Society 12-2012 Avian Diversity and Habitat Use on Wetland Reserve Program Lands in the Lower Missouri River Valley Eric C. Hopps United States Department of Agriculture, [email protected] Follow this and additional works at: https://digitalcommons.unl.edu/tpn Part of the Biodiversity Commons, Botany Commons, Ecology and Evolutionary Biology Commons, Natural Resources and Conservation Commons, Systems Biology Commons, and the Weed Science Commons Hopps, Eric C., "Avian Diversity and Habitat Use on Wetland Reserve Program Lands in the Lower Missouri River Valley" (2012). The Prairie Naturalist. 47. https://digitalcommons.unl.edu/tpn/47 This Article is brought to you for free and open access by the Great Plains Natural Science Society at DigitalCommons@University of Nebraska - Lincoln. It has been accepted for inclusion in The Prairie Naturalist by an authorized administrator of DigitalCommons@University of Nebraska - Lincoln. The Prairie Naturalist 44:79–97; 2012 AVIAN DIVERSITY AND HABITAT USE ON WETLAND RESERVE PROGRAM LANDS IN THE LOWER MISSOURI RIVER VALLEY ERIC C. HOPPS1 657 South 29 Road, Syracuse, NE, 68446 USA ABSTRACT A primary objective of the Wetland Reserve Program (WRP) is to provide habitat for migratory birds throughout all seasons of the year. Comprehensive avian assessments are lacking and limit our ability to evaluate the benefits of the WRP to continental bird populations. I investigated avian species occurrence on WRP lands within the Lower Missouri River Valley (LMRV), Nebraska, USA, from March 2010 to February 2011. Ten WRP habitat types are described based on plant community assemblages and observed hydrological regimes. Estimates of avian species richness were greatest in lowland forest (n = 115), lowland woodland (n = 83) and upland forest (n = 77) habitats. Taxonomic measures of avian diversity differed between habitat types but was similar in respect to season. Ecological habitat types ranked according to avian preference revealed forest and wetland communities to be significantly utilized across the entire species assemblage as compared to grassland habitats. Ordina- tion displayed similarity within grouped ecological habitat types and was supportive of a high dimensional community structure. Approximately one-half of all species documented met breeding level criteria, with 64 species confirmed as breeding. Taxonomic structure of breeding birds did not differ from the total WRP avian assemblage. I conclude that the regional and historical species pool within the LMRV remains largely intact and that WRP restorations exhibit the full complement of avian assemblage. KEY WORDS avian diversity, habitat use, Lower Missouri River Valley, species richness, taxonomic distinctness, Wetland Re- serve Program, WRP The Wetland Reserve Program (WRP) represents a sub- Duffy et al. 2011, Steven and Gramling 2011). Additionally, stantial investment by the United States (U.S.) government more localized investigations such as Summers (2010) thesis and constitutes a major effort aimed at restoring and protect- regarding avifaunal use of bottomland forests are needed to ing wetland habitats in the U.S. Between the years 1992 – more adequately evaluate WRP restorations. In contrast, the 2011, ≥1,000,000 ha of land were enrolled in program agree- grassland equivalent USDA Conservation Reserve Program, ments with projects represented in all 50 states. In Nebraska has received considerable attention and its benefits to a suite (NE), 127 million U.S. dollars were allocated between the of biotic and abiotic factors have been largely documented years 1993 – 2011 to conserve approximately 35,000 ha of (Haufler 2005, Gleason et al. 2008). Thus without more de- wetland and associated upland habitats (R. Epperson, Natural tailed investigations relating the degree of association be- Resources Conservation Service, personal communication). tween WRP restoration activities and biological responses, The WRP is administered by the Natural Resources Con- a more complete measure of the programs merit cannot be servation Service (NRCS) under the direction of the U.S. gained. Department of Agriculture (USDA). Initially authorized as A fundamental interpretation of ecological health gener- a programmatic component of the 1990 Food Agriculture, ally includes some type of measurement regarding biologi- Conservation and Trade Act, the WRP has several targeted cal diversity (see Niemi and McDonald 2004). Avian com- objectives including an emphasis on restoring, creating or munities in particular provide a mechanism for evaluation enhancing wetland habitat for migratory birds (Natural Re- of environmental variables and correlations to conservation sources Conservation Service 2010). Quantitative informa- objectives (Canterbury et al. 2000). Of all avian diversity tion, however, linking the environmental benefits of the WRP measures, species richness dominates the literature and in- to fish and wildlife species is limited (Gray 2005). In particu- deed entire treatises have been devoted to the subject (e.g. lar, avian response to restoration efforts has thus far been lim- Adams 2009). Derivations of species richness have been ited to qualitative descriptions with few analytical measures supplemented in recent decades by the application of predic- (Rewa 2005). King et al. (2006) provide a detailed overview tive estimators (see Hortal et al. 2006) increasing the use of of the role and status of the WRP in the Mississippi Allu- species richness as a surrogate measurement of biological di- vial Valley, but acknowledge that a lack of scientific research versity (Gaston and Spicer 2004). In addition, new branches has limited evaluation of the program’s impact on wildlife of biological measurement have emerged that are less reli- populations. Recent information derived from the USDA ant on species equitability but take account of such aspects Conservation Effects Assessment Project provides regional as taxonomic, phylogenetic, genetic or functional relation- inferences to avian use of WRP habitats but quantitative data ships (see Magurran 2004). Not surprisingly, Schweiger et appears mixed (Frazier and Galat 2009, Faulkner et al. 2010, al. (2008) recommend a complimentary use of both species 1 Corresponding author email address: [email protected] 80 The Prairie Naturalist • 44(2): December 2012 richness and phylogenetic measurements that more detailed by above normal temperatures (avg. 11.1° C + 1.3) and mechanistic relationships between the two may be gained. above normal precipitation (883.9 mm + 118.9 mm; National Because WRP restorations within the LMRV encompass a Weather Service 2011). The Missouri River exceeded flood variety of habitat types, the application of multiple diversity stage south of the Platte River on three occasions between 16 measures may provide insight into avian community struc- March and 9 October. Flood waters were restricted to areas ture and complement future restoration objectives. riverward of constructed levees. Furthermore, habitat selection in birds is motivated by numerous external and internal causations and is expressed N in a variety of adaptations, both physiologically and behav- River Mile 703 ! iorally (Cody 1985). Correlating the role of specific or even ! broad habitat types to avian selection, however, requires ! !! !! ! among other things, a measurement of availability and use !!! ! ! ! ! ! before measures of preference can be ascertained (Johnson ! ! 1980). Therefore, conservation, restoration, and management ! ! of naturalized habitats is inextricably linked to those species or suites of species targeted for assembly. Consequently, if Desoto NWR avian assessments of the WRP are to be determined, baseline ! information as to the availability and use of specific habitat Nebraska types associated with program restorations must be quanti- fied. Here I use two principle measures of diversity (species richness and taxonomic distinctness) to investigate avian as- Platte River semblages on WRP lands within the LMRV. Specifically, my ! objective was to: (1) measure the relative contributions of !! categorized WRP habitat types to overall avian species rich- ! ! ness and taxonomic structure, (2) determine habitat prefer- ! ! !! !! ences across the entire species assemblage based on avail- !!!! ! ! !!! Iowa ! ! ability and use, and (3) examine seasonal variations in avian ! !! ! ! Missouri diversity. Two ancillary measures also are explored; compari- ! !!! sons of regional and historical species lists to WRP avian tax- onomic structure and documentation of WRP avian breeding ! ! ! Squaw Creek NWR activity relative to described WRP habitat types. ! ! ! ! River Mile 495 ! STUDY AREA Kansas Figure 1. Map indicating site locations and approximate My study area consisted exclusively of individual WRP 334 km length of study area between river mile 703 and 495 easement sites (n = 67) within a 334 km stretch of the LMRV along the Lower Missouri River Valley, Nebraska, Mar 2010 (Fig. 1). All study sites were west of the Missouri River chan- to Feb 2011. nel and located between Thurston County, NE (river mile 703) and Richardson County, NE (river mile 495; U.S. Army Corp of Engineers 2009). I selected study sites from a pool Vegetation Characteristics