Webless Migratory Game Bird Program - U.S. Fish and Wildlife Service

More documents

Recommendations

Info

SANDHILL CRANE NEST AND CHICK SURVIVAL IN NEVADA CHAD W. AUGUST, Department of Natural Resources and Environmental Science, University of Nevada- Reno, Reno, NV, 89512 (c.w.august@gmail.com) JAMES S. SEDINGER, Department of Natural Resources and Environmental Science, University of Nevada- Reno, Reno, NV, 89512 CHRISTOPHER A. NICOLAI, United States Fish and Wildlife Service, 1340 Financial Boulevard, Suite 234, Reno, NV 89502 Graduate Student: Chad W. August (M.S.); Final Report Introduction Sandhill cranes (Grus canadensis) are among the longest lived (annual survival rates = 0.86-0.95; Tacha et al. 1992), and have the lowest recruitment rates of any game bird in North America (Drewien et al. 1995). Population growth of sandhill cranes is therefore most susceptible to changes in recruitment rate of young into the breeding population, in the absence of harvest or additional sources of adult mortality. Because sandhill cranes exhibit low fecundity, with small clutch size (1.94 ± 0.02, Drewien 1973) and low incidence of renesting (1.5-10.5% of total nests [Austin et al. 2007]), nest success may limit recruitment and therefore population growth. Human modification of the landscape influences nest success for birds, often by influencing predation (Stephens et al. 2003). Roads may attract nest predators by increasing abundance of carrion (Knight and Kawashima 1993). Roads have been associated with increased reproductive success of common ravens (Corvus corax) because of anthropogenic food sources associated with roads (Kristan 2001). Ravens are an important egg predator for sandhill cranes in the western U.S. (Walkinshaw 1949, Drewien 1973, Littlefield 1976, Littlefield and Thompson 1987). No studies have yet documented impacts of human development, including roads, on nest survival of sandhill cranes. Previous studies on nest success of greater sandhill cranes (Grus canadensis tabida; hereafter cranes) focused on the importance of water depth (Austin et al. 2007, Ivey and Dugger 2008, McWethy and Austin 2009) and vegetation height surrounding nests (Littlefield and Ryder 1968), and examined effects of land management that reduce nesting cover (Littlefield and Paullin 1990, Austin et al. 2007, Ivey and Dugger 2008). These studies did not, however, examine possible direct impacts of grazing on nest success. Because livestock often use mesic habitats in the arid 42 west (Fleischner 1994), impacts of livestock on nest survival of cranes is possible and should be assessed. Few studies have accounted for variation in crane nest survival within a year (Austin et al. 2007, Ivey and Dugger 2008). No studies have attributed intraseasonal variation in nest survival associated with a particular environmental factor. Previous research has focused primarily on productivity of nesting cranes on national wildlife refuges, with limited studies on private agricultural land. Although refuges may provide important habitat, the overall contribution to population dynamics of cranes nesting on state and federal wildlife management areas may be relatively minor, because suitable habitat may largely occur on private land. Chick (hereafter colt) survival is the least understood component of recruitment in cranes. Previous studies have focused on identifying direct causes of colt mortality, including predators and disease (Littlefield and Lindstedt 1992, Desroberts 1997, Ivey and Scheuering 1997), or habitat use. Although this may be informative for selective management of causes of mortality, the relative contribution of other environmental factors is unknown. No studies have estimated colt survival relative to time-dependent factors such as weather and hatching date. Mortality of precocial young is often high early in development, and survival probability commonly increases with age (Flint et al. 1995, Stafford and Pearse 2007, Fondell et al. 2008), which has been attributed to increased ability to thermoregulate, forage, and evade predators during the growth period. Weather may have greater effect on survival at young ages, when chicks are more susceptible to cold temperatures. Also, inherent heterogeneity in traits affecting survival of colts allows selective removal of lower-quality individuals. Although previous studies have demonstrated high mortality of young colts
(Bennett and Bennett 1990, Nesbitt 1992), no studies so far have estimated daily survival rates of colts. Our objectives were to estimate daily nest survival rates, nest success, and prefledging survival of cranes nesting primarily on private lands in northeastern Nevada. We hypothesized nest survival would be negatively related to human development and density of crane pairs. Among land-use practices, we hypothesized survival would be lowest for nests within summer-grazed fields, because of disturbance by livestock. Study Area Our study area encompassed Elko, White Pine, and extreme northern Lincoln Counties in northeastern Nevada, USA (Fig. 1). Topography was characterized by north-south oriented mountain ranges and associated basins (Fiero 1986). Average annual precipitation and average annual snowfall in Elko, NV during this study was 24 cm and 73 cm, respectively. Average daily temperatures from April-June in Elko, NV during this study ranged from 21° C to 2° C. Elevation in the study area ranged from approximately 1,300 m at the edge of the Great Salt Lake Desert, to nearly 4,000 m at Wheeler Peak. Lower elevation areas in the study area were used primarily for cattle grazing and native hay production in pastures irrigated by geothermal springs and from intermittent mountain streams via diversion ditches. Although 86% of the land area is in public ownership in Nevada, >85% of lowland meadow habitat is privately owned (McAdoo et al. 1986). Field work was performed at a mean elevation of 1,757 ± 6 m and directed towards known concentrated breeding areas of cranes in northeastern Nevada (Rawlings 1992). We divided the study area into five subareas each representing a concentrated crane breeding area (Fig. 1): Ruby Valley Area (composed of Ruby, Secret, Steptoe, Spring, and Lake Valleys), Huntington Valley (composed of Huntington Creek Floodplain and Mound and Newark Valleys), Lamoille Valley Area (composed of Humboldt River Floodplain and Lamoille and Starr Valleys), Independence Valley Area (composed of South Fork of the Owyhee River Floodplain and Independence Valley), and North Fork Area (composed of O’Neil Basin, Thousand Springs Valley, and floodplains of the Upper North Fork drainages of the Humboldt River, Bruneau River, Salmon Falls Creek, and Mary’s River). 43 Methods Field Methods Nesting data.—We searched for nests in hay meadows and pastures in northeastern Nevada from early April to early July in 2009 and 2010. We searched wetmeadow habitat in pastures and hay fields composed of grasses (Poa spp.), rushes (Juncus spp.), and sedges (Carex spp.). We also searched emergent vegetation along slow-moving streams and in beaver ponds, within natural and artificial ponds, and within marshes containing common cattail (Typha latifolia), hardstem bulrush (Scirpus acutus), and willow (Salix spp.). We began searches on 7 April in 2009 and 11 April in 2010 and searched for nests daily between 1 hr after sunrise and 1 hr before sunset. We focused our nest searching efforts in areas where cranes were present and signs of breeding were observed. We located active crane nests during searches on foot (n = 120 nests), helicopter (n = 37) and fixed-wing aircraft (n = 28) surveys, remote observations using spotting scopes or binoculars (n = 18), and canoeing (n = 3). We spent ≤2 consecutive days searching for nests at each property and rotated among four subareas (≤5 consecutive days per subarea) to ensure even coverage of the study area and an adequate sample of nests spanning the entire nesting season (Fig. 1). Figure 1. Location of greater sandhill crane study area and five subareas in northeastern Nevada, USA, 2009-2010.
Page 1 and 2: U.S. Fish & Wildlife Service Webles
Page 3 and 4: CONTENTS Development and History of
Page 5 and 6: HISTORY AND ADMINISTRATION OF THE W
Page 7 and 8: Program Administration The USFWS Pr
Page 9 and 10: Appendix A - Priority Information N
Page 11 and 12: Table 1. Harvest and crippling of m
Page 13 and 14: idge between current monitoring eff
Page 15 and 16: Figure 1. Estimated age ratios of m
Page 17 and 18: other, showing similar behavior (e.
Page 19 and 20: Table 5. Detection probability and
Page 21 and 22: mechanism for accurate aging of whi
Page 23 and 24: Currently laboratory measurements o
Page 25 and 26: Band-tailed Pigeons BAND-TAILED PIG
Page 27 and 28: flux:rock), fused at 1000°C in a m
Page 29 and 30: The mineral station design was adju
Page 31 and 32: unripe], cascara, and blue elderber
Page 33 and 34: at the station each day ranged from
Page 35 and 36: that Interior birds tended to retai
Page 37 and 38: Sandhill Cranes POPULATION GENETIC
Page 39 and 40: distinguishing between nearly ident
Page 41 and 42: Table 2. Pairwise Fst Values betwee
Page 43 and 44: VHF transmitters were synchronized
Page 45: Alternatively, a different survey m
Page 49 and 50: Spatial Data Landscape-scale data
Page 51 and 52: time-dependent variable of minimum
Page 53 and 54: We found colt survival was lower on
Page 55 and 56: McWethy, D. B., and J. E. Austin. 2
Page 57 and 58: Recent advancements in technology a
Page 59 and 60: Wildlife Resource Agency, Obion (So
Page 61 and 62: Figure 4. Preliminary breeding terr
Page 63 and 64: American Woodcock HABITAT USE AND O
Page 65 and 66: Figure 2: Map of a pointing dog tra
Page 67 and 68: Figure 4: Kriged 13th secondary fea
Page 69 and 70: Texas A&M University, College Stati
Page 71 and 72: ASSESSMENT OF TECHNIQUES FOR EVALUA
Page 73 and 74: ivers, marshes, and shrub swamps. V
Page 75 and 76: adio-marked broods 5-7 days per wee
Page 77 and 78: adult female, considerably lower th
Page 79 and 80: FACTORS AFFECTING DETECTION OF AMER
Page 81 and 82: We classified land-cover types at e
Page 83 and 84: were neighbor = 1.0, observer = 1.0
Page 85 and 86: was included within the official su
Page 87 and 88: Beyer, H. L. 2004. Hawth's Analysis
Page 89 and 90: Marshbirds THE EFFECT OF WATERFOWL
Page 91 and 92: Table 2. Relative Importance of mod
Page 93 and 94: nests to account for repeated measu
Page 95 and 96: Literature Cited Bogner, H. E. and
Page 97 and 98:
a common nest substrate. Tall forms
Page 99 and 100:
despite rails’ apparent ability t
Page 101 and 102:
EVALUATION OF AN EXPERT-BASED LANDS
Page 103 and 104:
IMPLEMENTATION OF THE NATIONAL MARS
Page 105 and 106:
truthed before the actual survey. H
Page 107 and 108:
IMPLEMENTATION OF A NATIONAL MARSHB
Page 109 and 110:
Table 1. Numbers of individuals of
Page 111 and 112:
was required because it was not rea
Page 113 and 114:
ESTIMATING POPULATION TRENDS, RELAT
Page 115 and 116:
This abstract represents a final ab
Page 117 and 118:
Virginia Rail (Rallus limicola), So
Page 119 and 120:
volunteers to cover new sites in la
Page 121 and 122:
Plain of Louisiana (Figure 1). We s
Page 123 and 124:
for concentrations of wintering sni
Page 125 and 126:
Table 1. Model selection results an
Page 127 and 128:
DEVELOPING OPTIMAL SURVEY TECHNIQUE
Page 129 and 130:
Conway, C. J., and J. P. Gibbs. 201
Page 131 and 132:
Figure 1. Red Slough Wildlife Manag
Page 133 and 134:
estimate visual obstruction 10 m fr
Page 135 and 136:
Table 3. Habitat measurements recor
Page 137 and 138:
Thesis, South Dakota State Universi
Page 139 and 140:
Reproductive Success and Survival i
Page 141 and 142:
The goal of the study is to address
Page 143 and 144:
When interacting with private lando
show all

Webless Migratory Game Bird Program - U.S. Fish and Wildlife Service

Create successful ePaper yourself

Delete template?

Save as template?