HABITAT SUITABILITY INDEX MODELS: PILEATED WOODPECKER

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Equations. In order to determine the life requisite value for the pileatedwoodpecker. the 51 values for appropriate variables must be combined throughthe use of equations. A discussion and explanation of the assumed relationshipbetween variables was included under Model Description. and the specificequations in this model were chosen to mimic these perceived biological relationshipsas closely as possible. The suggested equations for obtaining thefood/ cover/reproduction value are presented below.Life requisiteEastern portion of range:Food/cover/reproductionCover typeEF.DF,EFW.DFWEguationLower of (V 1x V z x V J)I/ 2or (V~x V s)I/2Western portion of range:Food/cover/reproductionEF,DF.EFW,DFW .Lower of (V 1x V z x V J)I/ 2or (V, x V,)1/2HSI determination. The HSI for the pileated woodpecker is equal to thelife requisite value for food/cover/reproduction.Application of the ModelDefinitions of variables and· suggested field measurement techniques (Hayset al. 1981) are provided in Figure 2. Note that V~ and VI are to be measuredonly in the eastern portion of the range of the pileated woodpecker. and V,and V, in the western portion of the range.Variable (definition)Percent tree canopyclosure [the percentof the ground surfacethat is shaded by avertical projection ofthe canopies of allwoody vegetation tallerthan 5.0 m (16.5 ft)J.Cover typesEF,DF,EFW,DFWSugoested technigueLine interceptFigure 2.Definitions of variables and suggested measurement techniques.11
Variable (definition) Cover types Suggested technigue ~Va Number of trees > 51 cm EF,OF,EFW, Quadratdbh/0.4 ha (20 inchesOFWdbh/l.0 acre) [actualor estimated number oftrees that are greaterthan 51 em (20 inches)diameter at breast height(1.4 m (4.5 ft) per 0.4 ha(~.O acre)].V J Number of tree stumps EF,DF.EFW, Quadrat> 0.3 m (1.0 ft) in OFWheight and> 18 cm(7 inches) diameterand/or logs> 18 cm(7 inches) diameter/0.4 ha (1.0 acre)[the actual or estimatednumber of treestumps greater than 0.3 m(1.0 ft) in height andgreater than 18 em(7 inches) in diameter,and/or logs greaterthan 18 em (7 inches)in diameter present peracre. Log diametershould be measured atthe largest point].V,. Number of snags > 38 em EF,DF,EFW, Quadrat(IS inches) dbh/0.4 haOFW(1.0 acre) [the numberof standing dead treesor partly dead trees,that are greater than38 em (15 inches) diameterat breast height(1.4 m/4.5 tt), andthat are at least 1.8 m(6 ft) tall, per 0.4 ha(1.0 acre). Trees inwhich at least 50% of thebranches have fallen, orare present but no longerbear foliage, are to beconsidered snags].Figure 2.(continued).12
Page 1 and 2: FWSJO BSe82l1 0.39APRIL 1983HABITAT
Page 3 and 4: FWS/OBS-82/10.39April 1983HABITAT S
Page 5 and 6: PREFACEThis document is part of the
Page 7 and 8: ACKNOWLEDGMENTSWe gratefully acknow
Page 9: Bull (1981) reported that pileated
Page 12 and 13: InterspersionThe minimum forest siz
Page 14 and 15: Habitat variableLife reguisiteCover
Page 16 and 17: EF, OF.EFW,OFWNumber of trees> 51 c
Page 20 and 21: Variable (definition)Average dbh of
Page 22 and 23: Conner, R. N., R. G. Hooper, H. S.
Page 24 and 25: ..National Wetlands ResearchCenter

HABITAT SUITABILITY INDEX MODELS: PILEATED WOODPECKER

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