Gale Monson Research Grants
Abstracts of reports from recipients
Breeding Biology of Red-faced Warblers in the Santa Catalina Mountains
Dillon, K.G., Arizona Cooperative Fish and Wildlife Research Unit, School of Natural Resources and the Environment, University of Arizona, 325 BioSciences East, Tucson, AZ 85721
Conway, C.J., U. S. Geological Survey, Idaho Cooperative Fish and Wildlife Research Unit, University of Idaho, PO Box 441141, Moscow, ID 83844
Red-faced warblers have a relatively restricted breeding range in the United States, but unusually high densities of breeding Red-faced Warblers occur in the Santa Catalina Mountains of southeastern Arizona. We have studied Red-faced Warblers breeding from 1800 meters to 2800 meters on Mount Lemmon since 2002, encompassing the entire elevational extent of the species’ breeding range. Very little is known about the breeding biology of this species, and we have learned much about their breeding behavior. One of the most intriguing observations that we’ve made is that birds at the top of the mountain typically lay fewer eggs than birds at lower elevations. Our research suggests that differences in nest predators may explain why high-elevation birds lay fewer eggs. We were also surprised to see that nestlings grew more rapidly at high elevation. Understanding the differences in breeding biology and behaviors among warblers at different elevations will help aid efforts to predict the effects of climate change on montane birds in the southwestern United States.
Migratory and Wintering Strategies of Yellow-eyed Juncos in Southeastern Arizona
Lundblad, C.G., Arizona Cooperative Fish and Wildlife Research Unit, University of Arizona, 104 Biosciences East, Tucson, AZ 85719, carl.lundbladATgmail.com
Conway, C.J., USGS, Idaho Cooperative Fish and Wildlife Research Unit, University of Idaho, P.O. Box 441141, Moscow, ID 83844
Yellow-eyed juncos (Junco phaeonotus) make facultative short-distance migrations along elevational gradients in the Sky Island mountain ranges of southeastern Arizona. From 2011-2012 we color-banded 850 juncos on their breeding grounds at five sites spanning the elevational extent of the species’ breeding range in the Santa Catalina Mountains. We surveyed each site for banded juncos every two weeks September-February and found evidence for female-biased migration. We found individuals moving between sites as early as the first week of September. Most movements away from breeding areas are assumed to be downslope, but we found evidence of some individuals temporarily moving upslope at the end of summer. The presence of persistent open ground was related to flock formation at some sites. Flocking behavior may represent an alternative strategy to migration and may explain uphill movements. All Juncos temporarily vacated breeding areas following extreme snow events. All major hypotheses proposed to explain partial migration predict the observed differences in migratory tendency among sex classes. We tested explicit predictions of each hypothesis in order to gain insight into the relative importance of each mechanism that could explain why some juncos migrate downslope and why others do not. Nests of resident individuals succeeded 59% of the time while those of migrants succeeded at a rate of 44%. Residents initiated nests an average of 2.5 days earlier than migrants, but nestling growth rate was not related to migratory status. Residents and migrants did not differ in response to simulated territorial incursions intended to measure interspecific aggression.
The Distribution and Extent of Heavy Metal Accumulation in Song Sparrows of the Upper Santa Cruz River Watershed
*Lester, M. B., 1110 E. South Campus Dr., Room 123, Tucson, AZ 85721, mlester126ATgmail.com
van Riper, C., III, 1110 E. South Campus Dr., Room 123, Tucson, AZ 85721
Riparian ecosystems in arid environments provide critical habitat for breeding, migratory, and wintering birds, yet are often at risk of contamination with heavy metals. Birds and other animals living in contaminated areas are susceptible to adverse health effects as a result of long-term exposure and bioaccumulation of heavy metals. Our study took place as part of a collaborative effort to quantify the level of contaminants in the upper Santa Cruz River watershed. We chose to examine five study sites and a reference site that reflect different potential sources of contamination. We investigated the extent of heavy metal accumulation in blood and feathers of Song Sparrows (Melospiza melodia) over two breeding seasons. Birds at our five study sites typically had higher metal concentrations than birds at our reference site, though most metals were below background concentrations determined from previous studies. Copper, mercury, nickel, and selenium in Song Sparrows did exceed background levels. Song Sparrows generally showed lower heavy metal concentrations compared to Killdeer (Charadrius vociferus) collected along the Santa Cruz River in 1998, however concentrations tended to be higher for Song Sparrows compared to Abert’s Towhees (Melozone aberti) and Yellow-breasted Chats (Icteria virens) sampled in 2008 and 2009. Continued monitoring of heavy metal concentrations in birds in the upper Santa Cruz watershed is recommended, as well as future studies examining how heavy metal contamination affects avian health and productivity.
Seasonality, Habitat, and Diet of Gray Vireos at Kofa NWR in Southwestern Arizona
Arnett, J. E., 7101 Jerstad Lane, Bldg. 500 Luke AFB, AZ 85309
Kondrat-Smith, C. (presenting author), 27324 N 219 Ave., Wittmann, AZ 85361
The winter distribution of Gray Vireo (Vireo vicinior) closely matches the distribution of small trees in the genus Bursera, particularly elephant tree (B. microphylla), that produce calorie-rich fruits. Thus, it is surprising that Gray Vireos have been reported by Gale Monson and others during the winter at Kofa National Wildlife Refuge (Kofa) in southwestern Arizona where no Bursera occur. Additionally, recent observations suggest that Kofa is an important early (e.g., late February and early March) migration stopover for north-bound vireos. To examine vireo occurrence and diet at Kofa, we conducted seven surveys from December 2012 to May 2013 at three canyons and two valley xeroriparian washes. We detected a surprisingly high number of vireos in December, including eight at Alamo Wash. Subsequently, a dramatic drop in vireo detections coincided with a hard freeze, followed by a gradual increase in detections in late March and April. We observed vireos eating caterpillars and possibly spiders. We did not observe vireos eating fruit, though mistletoe and wolfberry fruits were plentiful. We conclude Gray Vireos may be more widespread than previously thought during the autumn and winter where arthropod prey is available and B. microphylla is absent until the first hard freeze occurs, after when vireos likely move to where B. microphylla fruit is available. Our results suggest that a winter-time monitoring strategy for the vireo and its habitat would need to consider the plasticity of the vireo’s winter distribution, diet, and habitat use.
Winter Distribution and Plumage Characteristics of Sagebrush and Bell’s Sparrows in Arizona
McCreedy, C.,3820 Cypress Dr., Petaluma, CA 94954,cmccreedyATpointblue.org
Kovach, A., G87 Rudman Hall, 46 College Rd., Univ. of New Hampshire, Durham, NH, 03824
Lester, M., 501 E 1st Ave #3, Salt Lake City, UT
The American Ornithologists’ Union recently split the former Sage Sparrow (Artemisiospiza belli) into two taxa, Sagebrush Sparrow (A. nevadensis) and Bell’s Sparrow (A. belli). Sagebrush Sparrow and the interior subspecies of Bell’s Sparrow (A.b. canescens) have similar plumage characteristics and call notes, and these similarities render separation of the two taxa problematic in the field. Both Sagebrush and Bell’s Sparrow winter in Arizona, and their respective wintering distributions in the state are not well understood. In February 2014 we captured 85 Artemisiospiza sparrows at five sites representing five distinct vegetation assemblages across southern and western Arizona. We used plumage and morphological characteristics described in previous work to identify 74 individuals in the hand; one bird was left unidentified due to ambiguity in its plumage characteristics and in its intermediate wing size. To test our field identifications, we sampled blood from these 75 individuals to establish sex and genetic identification. Our field identifications were consistent with lab classification for 68 of 74 (92%) of our samples. We are further sequencing the gene for the remaining 6 samples, as the restriction fragment length polymorphism (RFLP) approach used by previous authors does not differentiate the species 100%. Our field identification success rate is thus preliminary and is a minimum.Preliminary results (considering only the 68 individuals with matching classifications) reveal that mixing between the two species was rare. At four sites only one species was present. At Robbins Butte (Maricopa Co.), 26 of 30 captures were identified as Bell’s Sparrow (87%). This segregation was unexpected and suggests the two species hold divergent habitat preferences on their wintering grounds in Arizona. We photographed all captures from multiple views, and we will also discuss key identification points that may be used to separate these species in the field.
A Survey of Spring Migration at Lake Havasu with an Emphasis on Waterbirds
Vander Pluym, David,2841 McCulloch Blvd N. #1, Lake Havasu City, AZ, 86403
The development of reservoirs along the Colorado River has changed the ecology of the region and offered habitat for many species of aquatic birds where none existed historically. Aquatic bird surveys were done to look at use of the location as a stopover site and to gain an understanding of what species may now use the area regularly in migration. I conducted surveys at the north end of Lake Havasu between mid-March and mid-May 2014. The main focus was on aquatic bird migration, although landbirds were also counted. An attempt was made to use sound recording equipment to detect nocturnal migration. This was done to see how effective this type of survey method would be, with negative results. A total of 41,292 individuals representing 59 species of landbirds and a total of 42,519 individuals representing 57 species of waterbirds were detected, excluding likely resident and breeding species, but including some likely wintering birds. Several aquatic species formerly considered rare were found regularly during the survey period and in recent years or were found in higher numbers than previously recorded, such as Common Loon, Eared Grebe, Red-necked Phalarope, and Bonaparte’s and Franklin’s gulls. This information can be used to judge future changes in aquatic bird use of reservoirs along the Colorado River.
Monitoring Diurnal Raptor Migration at a High-Elevation Site in the Central Highlands of Arizona: A Pilot Study during Fall 2013 and Spring 2014
Smith, Z., Independent Raptor Biologist, 843 N. Citrus Ave., Los Angeles, CA 90038, zsgavilanATgmail.com, gavilanphoto.smugmug.com
Monitoring raptor migration at strategic locations has been in practice for several decades at numerous sites across North America. Most migrant raptor species are difficult to monitor during the breeding season and migration counts can provide data to help track population changes. Sites in western United States are typically located on north-south trending mountain ridges that create orographic wind currents that provide energy-saving lift for migrant birds. During the fall of 2013 and the spring of 2014, I made observations of migrant raptors from the Sierra Prieta Overlook in the Bradshaw Mountains west of Prescott, Arizona. The most common species observed during fall include Turkey Vulture (35% of flight), Cooper's Hawk (22%), Sharp-shinned Hawk (15%), Red-tailed Hawk (10%), and American Kestrel (9%). During spring, the most commonly seen species were Cooper's Hawk (24%), Swainson's Hawk (21%), Turkey Vulture (21%), and Sharp-shinned Hawk (11%). The majority of birds observed passed the site on days when the wind direction had a westerly component.
Gray Hawk Expansion on the San Pedro River: Density Dependence, Habitat, and Diet
La Porte, A., School of Life Sciences, Arizona State University, Tempe, PO Box 874501, AZ 85287, Email: ariana.laporteATgmail.com Website: http://azgrayhawks.tumblr.com Twitter: @AZGrayHawks
The Gray Hawk population along the San Pedro River has been expanding since it was first documented in the late 1970s. Gray Hawks first settled the northern areas of the San Pedro National Riparian Conservation Area (SPRNCA), where mesquite flanks the cottonwood gallery. But within the last two decades they have begun nesting in the southern, grassy end of the SPRNCA, and in the sycamore, juniper, and Madrean oak forests of the Huachuca Mountains. What might this population expansion indicate? The Fretwell-Lucas model of habitat selection states that preferred areas are settled first, and “overflow” individuals are consigned to lower quality habitats where productivity is lower. But are grassland and oak forest marginal habitat for these raptors? I am comparing Gray Hawk productivity and diet of pairs in these newly settled areas to those in historically occupied ones to determine how these raptors use different types of habitat and whether the Fretwell-Lucas model of population growth applies. Preliminary results suggest that overall productivity has not declined as the population has expanded. Though the percentage of nests that succeed is lower in newly settled areas, successful pairs produce more chicks in grassland and oak territories than those in historically occupied mesquite ones. These observations are from the 2015 breeding season only, and further research will determine whether these patterns hold over time. More data are needed to support a robust conclusion.
Gray Hawk Expansion in the San Pedro River Valley: Habitat, Diet, and Density Dependence
La Porte, A., School of Natural Resources and the Environment, University of Arizona, 138 E. 14th St., Tucson, AZ 85701-2428, ariana.laporteATgmail.com
Simpson, R. K.*, School of Life Sciences, Arizona State University, PO Box 874601, Tempe, AZ 85287-4601, email@example.com; McGraw, K. J., School of Life Sciences, Arizona State University, PO Box 874501, Tempe, AZ 85287-4501
|Join AZFO click here|