Avian use of xeroriparian ecosystems in the North American warm deserts, RR Johnson, LT Haight

Tags: Chihuahuan Desert, Sonoran Desert, vegetation, plots, censusing, northwestern Sonora, R. Roy Johnson, Carpodacus mexicanus, J. M., American Ornithologists' Union, Lowe, Range Exp, Maricopa County, Arizona, Arizona landscapes, Polioptila melanura, Ferruginous Pygmy-Owls, White-crowned Sparrows, Horned Owls, upland habitat, Phainopepla nitens, Yellow-rumped Warblers, Western Screech Owls, Regulus calendula, Range Expt, Prosopis velutina, Cercidium floridum, University of Arizona Press, Lois T. Haight, Vizcaino Desert, Haight, Punta Prieta, Baja California, upland ecosystems, vegetation types, streamside vegetation, subdivisions, Baja California, riparian vegetation, Arizona, riparian habitat, riparian habitats, Arizona Upland, University of Arizona, dense vegetation, University of Arizona, Natural Resources, census, L. T. Haight
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Avian Use of Xeroriparian Ecosystems in the North American Warm Deserts1 R. Roy Johnson2 and Lois T. Haight 2
Abstract.--Results of xeroriparian avian censuses are compared with paired desert upland censuses for various subdivisions of the Sonoran Desert. With few exceptions xeroriparian habitat supports 5 to 10 times the population densities and species diversity of surrounding desert uplands.
INTRODUCTION AND BACKGROUND
The value of riparian ecosystems as avian habi-
classified the vegetation associated with these
tat was first quantified in the late 1960's and early wash systems (Lowe and Brown 1973, Brown et al.
1970's (Carothers and Johnson 1971, Johnson 1971, Carothers et al. 1974). These earlier avian investi-
1979).
gations, however, dealt entirely with wet riparian ecosystems (hydroriparian and mesoriparian) and
In 1980 we began avian investigations at Organ Pipe Cactus National Monument in the same region
although dry riparian habitats had been defined a
where Hensley (1954) had conducted his earlier stu-
decade earlier as "desert riparian" (Lowe 1961),
dies. We are measuring species distribution and
little has been done either qualitatively or quanti-
abundance of birds in various habitats during the
tatively to further characterize these xeroriparian
different seasons of the year. Dry watercourses and
ecosystems. These earlier avian studies were concerned with
their attendant xeroriparian vegetation often constitute almost 10% of the habitat of an area 3 . This is especially noticeable for 1st, 2nd, and
species diversity and population densities of breed-
3rd order washes in desert faotnills (Johnson et al.
ing populations. One early study took a cursory
1984). Our colleagues and other arid lands ecolo-
look at wintering riparian birds (Johnson and
gists generally agree that birds and other verte-
Douglas 1972) and another more detailed analysis
brates are apparently much more common along these
was made of the importance of wet riparian systems
well-vegetated washes. However, the only definitive
as migratory corridors and stopover habitat for
papers we find for the North American deserts which
transients (Stevens et al. 1977). A later analysis
address this issue are by Raitt and Maze (1968) for
of the importance of the riparian zone to the lowland breeding avifauna of the southwestern United
the Chihuahuan Desert, and Austin (1970) for the Mohave Desert. Both of these papers, however, give
States also treated only wet riparian habitats
population densities only for the breeding season.
(Johnson et al. 1977). Although there has been a
Therefore, we have established methodology for com-
thorough documentation of the loss of wet riparian
paring species diversity and population densities
ecosystems due to water projects and agricultural
along these desert washes during all seasons and
and urban development (Johnson and Carothers 1982),
for comparing these data to the same information
,: .. ~
there has been no similar quantification of the loss
for nearby upland plots of equal size. The width
of dry riparian habitat. This paper discusses a
of the xeroriparian plot (channel plus riparian
pilot project designed to quantify the high value
habitat on both sides) varies from wash to wash,
of desert washes and arroyos as avian habitat.
but the paired xeroriparian and upland plots in
each instance are of equal size. Plot length de-
pends on several factors including amount of stream-
study area AND METHODS
course braiding, density of riparian vegetation and
negotiability of the wash. Severe stream braiding
The vegetation along dry desert watercourse
in large wash systems often causes problems in
has been recognized as important habitat for birds
censusing. These problems are related to total
for several decades (Hensley 1954). Lowe (1961,
width of the wash system and relative amount of
1964) first delineated and defined these "desert
vegetation to chan~el width (e.g., a single channel
riparian" ecosystems and further discussed and
with a single band of riparian vegetation on each
side vs. a multi-channeled wash with a reticulum of
1Paper presented at the First North American
riparian vegetation). A single investigator, for
Riparian Conference, Tucson, Arizona, April 16-18,
1985.
2R. R. Johnson and Lois T. Haight are with the National Park Service and School of Renewable
3Warren, Peter L. 1985. Personal conversation. Office of Arid Lands Studies, University of Arizona,
natural resources, University of Arizona, Tucson, AZ. Tucson, Ariz.
156
example, can census a half kilometer plot in a single-channeled, third order wash in less than an hour while a braided wash of similar size and order may require a similar amount of time by each of three or four investigators because of the greater width of the wash and the associated dense vegetation. Denser vegetation requires more census time because of decreased visibility and, generally, larger numbers of birds. Dense vegetation in the wash channel, large rocks, and deep sand all increase the difficulty of walking a census "line." Upland plots were selected far enough from xeroriparian plots to minimize movement of birds between each xeroriparian and matched upland plot. This is especially important for breeding bird censuses where one is trying to determine territorial pairs. By sitting on a nearby hill or the highest part of the upland plot for an hour or two in the
morning (and, if possible, off and on throughout the day) one can check the frequency of movement of birds between paired plots. Censuses should be run on a minumum of two days in a row, reversing the census order for riparian and upland plots from the first to the second day. The time of day for censusing varies greatly, depending on season, local weather, and avian activity. Censusing generally begins at sunrise. During the breeding season, however, censusing generally begins as soon as light is sufficient to allow the location and identification of birds. Some species, e.g., the Brown Towhee (Pipilo fuscus), sing even before light and may cease at sunup. By contrast, we often postpone winter censusing for an hour or more after sunrise, especially for a canyon or a heavily vegetated wash that remains shaded and cool. In such situations the census taker(s) can
Table l.--Randomly selected sample winter census from paired plots in southwestern Arizona's Arizona Upland subdivision of the Sonoran Desert.
Paired plots
500 by 60 m in Alamo Wash, Ajo Mountains and Alamo Canyon Upland, Organ Pipe Cactus National Monument
weather conditions: Still, Clear 30 December 1981, 0825 to 0925 h
R. Roy Johnson
Cornmon name l
Scientific name
Number of individuals
Xeroriparian2
Upland 3
plot
plot
Common (Gilded Flicker) Gila Woodpecker Ladder-backed Woodpecker Verdin Rock Wren Cactus Wren Black-tailed Gnatcatcher Ruby-crowned Kinglet Curve-billed Thrasher Crissal Thrasher Phainopepla Black-throated Sparrow Brown Towhee Dark-eyed Junco White-crowned Sparrow House Finch Thrasher sp.?
Colaptes auratus mearnsi
1
Melanerpes uropygialis
4
Picoides scalaris
1
Auriparus flaviceps
2
Salpinctes obsoletus
1
Campylorhynchus brunneicapillus 3
Polioptila melanura
3
Regulus calendula
2
Toxoxtoma curvirostre
1
Toxostoma dorsale
1
Phainopepla nitens Amphispiza b~ta
6 males, 6 females 9
Pipilo fuscus
4
Junco hyemalis
8
Zonotrichia leucophrys
19
Carpodacus mexicanus
2
Toxostoma sp.?
2
Individuals (incl. 75
o
2 unidentified
thrashers)
Species
16
o
lAfter A.O.U. Checklist, sixth edition (American Ornithologists' Union, 1983). 2predominant vegetation of Prosopis velutina, Lycium spp., Ambrosia ambrosioides, Sapium biloculare, Cercidium floridum. 3predominant vegetation of Cereus giganteus, f. thurberi, Opuntia fulgida, Ambrosia deltoidea, Larrea, Cercidium microphyllum.
157
Table 2.--Randomly selected sample winter census from paired plots in northwestern Sonora's Lower Colorado subdivision of the Sonoran Desert.
Paired plots 500 by 60 m in Papago Wash, Pinacate Area, Sonora,Mexico and Papago Tanks Upland
Common name l
R. Roy Johnson 31 December 1981, 9845 to 0930 h
Scientific name
Number of individuals
XeroriparianZ
Upland 3
plot
plot
Mourning Dove Ladder-backed Woodpecker Verdin Black-tailed Gnatcatcher Crissal Thrasher Phainopepla Ruby-crowned Kinglet Yellow-rumped Warbler House Finch
Zenaida macroura Picoides scalaris Auriparus flaviceps Polioptila melanura Toxostoma dorsale Phainopepla nitens Regulus calendula Dendroica coronata Carpodacus mexicanus
9 males,
1 1 6 5 1 5 females 1 1 2
Individuals
32
o
Species
9
o
lAfter A.O.U. Checklist, Sixth edition (American Ornithologists' Union, 1983). 2predominant vegetation of Olneya, Cercidium floridum, Prosopis, Acacia gregii, Lycium, Hyptis emoryi, Phoradendron californicum. 3predominant vegetation of Larrea, Ambrosia dumosa.
begin the census as soon as avian activity begins. This requires being on the plot at sunrise to monitor activity. Because of open terrain and scant vegetation, upland plots can nearly always be censused by a single observer. Direct counts are conducted as the census taker traverses the plot along a median "line." Heavily wooded washes often need two observers, one on each side of the channel or one in the bottom and one walking parallel on an overlooking hill or bank. In such cases, upland counts are also conducted by the same two observers for purposes of standardization. Horned Owls (Bubo virginianus), Western Screech Owls (Otus kennicottIi), Ferruginous Pygmy-Owls (Glaucidium brasilianum), and Elf Owls (Micrathene whitneyi) are all active during crepuscular hours, at dusk and/or dawn, and present a special censusing problem (Johnson et al. 1981). DISCUSSION, CONCLUSIONS, AND SUMMARY Paired strip transects were established for comparing avian populations in xeroriparian habitat (common along dry desert watercourses) with those populations in surrounding desert upland habitat. From 1980-1985 these plots were censused for avian species diversity and population densities in the Mohave Desert, Chihuahuan Desert, and subdivisions of the Sonoran Desert (Shreve 1941). We had hypothesized that dry riparian hab"itats should be affected by the same factors which result in greater avian diversity and densities in wet riparian ecosystems
compared to adjacent uplands. On rare occasions we have also observed high avian use of desert upland habitats during seasons other than summer. Such rare observations of exceptional upland use have included hundreds of White-crowned Sparrows in creosotebush flats near Phoenix, Arizona in winter. In spring we have recorded flights of warblers in the desert uplands near Phoenix (especially Wilsons, Townsend's, and Yellow-rumped Warblers) as well as sparrows in creosotebush-microphyll desert near Tucson and Phoenix (mostly Black-chinned, Brewer's, Chipping, and White-crowned Sparrows). Xeroriparian plots were established in the Arizona Upland subdivision of the Sonoran Desert at Blue Point Cottonwoods (Johnson and Simpson 1971), Saguaro National Monument near Tucson, and Organ Pipe Cactus National Monument (table 1) on the U.S.Mexican boundary. In addition we established plots in the Pinacate lava fields of the Lower Colorado subdivision of the Sonoran Desert in northwestern Sonora, Mexico (table 2). Several plots were studied in the Central Gulf Coast of Sonora, Baja California, and Baja California Sur as well as the Vizcaino subdivision of the Sonoran Desert in Baja California (table 3). Sample plots were run in the Plains of Sonora, Foothills of Sonora, and Magdalena subdivision of the Sonoran Desert in northern Mexico. Although a complete analysis by season for the desert regions is currently underway, the purpose of this report is to demonstrate our findings regarding the high relative value of xeroriparian ecosystems as avian habitat. The tables in this paper present the
158
results of randomly selected censuses from three of the seven subdivisions of the Sonoran Desert in which we worked. Similar information has been provided elsewhere for the Chihuahuan Desert (Johnson and Haight, in press). Censusing in all desert subdivisions--extensively in some, preliminarily in others--and a wide variety of vegetation types has produced similar results--species diversity and/or population densities of approximately five to ten times that of identical plots in the surrounding uplands--with one exception. Plots censused during migration in March 1981, near Punta Prieta, Baja California produced similar results for xeroriparian and upland plots. This is a particularly densely vegetated section of the Vizcaino Desert with Tree species consisting of
boojums (Fouquieria columnaris) and cardones (Cereus pringeli) and numerous shrubs (e.g., Viscainoa, Opuntia molesta, Ambrosia spp., Simmondsia, and others). Large numbers of Fringillids and other species were moving through the hillside vegetation as well as along the denser streamside vegetation. Our data demonstrate a much greater avian use of xeroriparian ecosystems when compared with upland ecosystems during all seasons in most of the subdivisions and the vegetation types in which we have worked in the Sonoran Desert. Preliminary investigations indicate that the same is true for most seasons in other subdivisions of the Sonoran Desert as well as for the Chihuahuan and Mohave deserts. Additional studies are now in progress to further quantify avian activities in xeroriparian ecosystems of the North American deserts.
Table 3.--Randomly selected sample winter census from paired plots in the Viscaino subdivision of the Sonoran Desert.
Paired plots 800 by 30 m in Catavina Arroyo, Baja California and Catavina Upland
Common name l
R. Roy Johnson and Lois T. Haight 27 December 1983, 0900 to 0940 h
Scientific name
Number of individuals
Xeroriparian2
Upland3
plot
plot
Verdin Rock Wren Black-tailed Gnatcatcher Loggerhead Shrike Brewer's Sparrow White-crowned Sparrow House Finch
Auriparus flaviceps Salpinctes obsoletus Polioptila ~elanura Lanius ludovicianus Spizella breweri Zonotrichia leucophrys Carpodacus Mexicanus
1 1 2 2 2 13 2 males + 2
Individuals
25
Species
7
28 December 1983, 0830 to 0945 h
Costa's (?) Hummingbird Black-tailed Gnatcatcher Gray Thrasher Phainopepla Green-tailed Towhee Black-throated Sparrow White-crowned Sparrow
Calypte costae Polioptila melanura Toxostoma cinereum Phainopepla nitens Pipilo chlor~ Amphispiza bilineata Zonotrichia leucophrys
Pair courting 5 3 + 2 singing Male 1 1 singing 18
Individuals
33
o
Species
7
o
lAfter A.G.U. Checklist, Sixth edition (American Ornithologists' Union 1983). 2predominant vegetation of Prosopis, Ephedra, Lycium, Acacia gregii. 3predominant vegetation of Larrea, Ambrosia cf. dumosa, Agave.
159
LITERATURE CITED Austin, G. T. 1970. Breeding birds of the desert riparian habitat in southern Nevada. Condor 72:431-436. Brown, D. E., C. H. Lowe, and C. P. Pase. 1979. A digitized classification system for the biotic communities of North America, with community (Series) and association examples for the Southwest. J. Arizona-Nevada Acad. Sci. 14 (Suppl.l):1-16. Carothers, S. W., and R. R. Johnson. 1971. A summary of the Verde Valley breeding bird survey, 1970. Ariz. Game and Fish Dept. Completion Report FW 16-10:46-64. Carothers, S. W., R. R. Johnson, and W. W. Aitchison. 1974. Population structures and social organization of southwestern riparian birds. Amer. Zool. 14:97-108. Hensley, M. M. 1954. Ecological relations of the breeding bird population of the desert biome in Arizona. Ecol. Monogr. 24:185-207. Johnson, R. R. 1971. Tree removal along southwestern rivers and effects on associated organisms. Amer. Phil. Soc. Yrbk. 1970:321-322. Johnson, R. R., B. T. Brown, L. T. Haight, and J. M. Simpson. 1981. Playback recordings as a special avian censusing technique. Studies in Avian Biology No. 6:68-75. Johnson, R. R., and S. W. Carothers. 1982. Riparian habitats and recreation: Interrelationships and impacts in the Southwest and Rocky Mountain Region. Eisenhower Cons. Bull. No. 12, USDA For. Servo Rocky Mtn. For. and Range Exp. Stn., Ft. Collins, Colo. 31 p. Johnson, R. R., and C. L. Douglas. 1972. Highways , and their impact on the wildlife of the pinyonjuniper-oak woodland in north-central Arizona. Ariz. Highway Dept., Phoenix. 149 p.
Johnson, R. R., and L. T. Haight. In Press. Avian use of xeroriparian systems in the Big Bend region, Texas. Proceedings 2nd Symposium on Chihuahuan Desert, C.D. Res. Inst., Alpine, Tex. Johnson, R. R., L. T. Haight, and J. M. Simpson. 1977. endangered species vs. endangered habi- tat. p. 68-79 In Proceedings of symposium on importance, preservation, and management of the riparian habitat. USDA For. Servo Gen. Tech. Rpt. RM-43 , Rocky Mtn. For. and Range Expt. Stn., Ft. Collins, Colo. 217 p. Johnson, R. R., and J. M. Simpson. 1971. Important birds from Blue Point Cottonwoods, Maricopa County, Arizona. Condor 73:379-380. Lowe, C. H., Jr. 1961. Biotic communities in the sub-Mogollon region of the inland Southwest. J. Ariz. Acad. Sci. 2(1) :40-49. Lowe, C. H. 1964. Arizona landscapes and habitat. p. 1-132 In C. H. Lowe (Ed.), The vertebrates of Arizona. University of Arizona Press, Tucson, Ariz. 270 p. Lowe, C. H., and D. G. Brown. 1973. The natural vegetation of Arizona. Arizona Resources information system Cooperative Publication. No.2. 53 p. Raitt, R. J., and R. L. Maze. 1968. Densities and species composition of breeding birds of a creosotebush community in southern New Mexico. Condor 70:193-205. Shreve, F. 1951. Vegetation of the Sonoran Desert. Cqrnegie Inst. Wash. Publ. 591. 192 p.; maps and photos. Stevens, L., B. T. Brown, J. M. Simpson, and R. R. Johnson. 1977. The importance of riparian habitats to migrating birds. p. 156-164 In Proceedings of symposium on importance, preservation, and management of the riparian habitat. USDA For. Servo Gen. Tech. Rpt. RM-43 , Rocky Mtn. For. and Range Exp. Stn., Ft. Collins, Colo. 217 p.
160

RR Johnson, LT Haight

File: avian-use-of-xeroriparian-ecosystems-in-the-north-american-warm.pdf
Title: Riparian ecosystems and their management: Reconciling conflicting uses
Author: RR Johnson, LT Haight
Author: USDA Forest Service - Rocky Mountain Research Station
Subject: RM-GTR-120: Avian Use of Xeroriparian Ecosystems in the North American Warm Deserts
Keywords: riparian habitats, endangered habitats, aquatic ecosystems
Published: Fri Oct 19 15:02:28 2012
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