Spatial ecology, habitat selection, and survival of wild turkey gobblers in a managed bottomland hardwood forest

Wild turkey (Meleagris gallopavo) males were captured and radio-tagged in a bottomland hardwood forest of south-central Louisiana. Turkeys were monitored year round from fixed telemetry stations on Sherburne Wildlife Management Area, Atchafalaya National Wildlife Refuge, and Bayou des Ourses to observe seasonal patterns of space use, habitat selection and survival from 2005-07. The largest seasonal home range was in fall/winter (966.41 ha; Oct 1-Feb 28). Spring home range (767.77 ha; Mar 1- May 31) size was lower than reported in previous studies and was a function of female availability. Season and age interacted to influence core area size (F5/63 = 2.35, P = 0.051), but not home range size (F5/63 = 1.49, P = 0.207). Males did not move about their home range differently before or during the breeding season (t20 = 1.11, P = 0.282). Additionally, males did not display spatial shifts of core areas before and during the breeding season at the population level (t20 = -0.92, P = 0.367). Upland forests and water-based forests were selected by adults and juveniles at all 3 spatial scales (habitat selection in home ranges vs. habitat availability across study area [1st order], habitat selection in core areas vs. habitat availability across home ranges [2nd order], and habitat availability across home ranges [3rd order]), whereas lowland forests were avoided at all 3 spatial scales. Habitat selection in spring was based on location of females. Water-based forests were essential to male habitat as they provide quality roosting and feeding sites. Survival was lowest in spring (0.43, SE = 0.09; Mar 1- May 31) due to the spring harvest. Fall/winter survival averaged 0.74 (SE = 0.05; Oct 1-Feb 28) and survival during summer averaged 0.74 (SE=0.06; Jun 1-Sept 30). Mean annual survival was 0.64 (SE = 0.06), among the highest ever reported for wild turkey males. The conservative harvest strategy on Sherburne was likely related to high survival rates for male

MIXING OF TWO GREATER SANDHILL CRANE POPULATIONS IN NORTHEAST OREGON

The Oregon Department of Fish and Wildlife (ODFW) Ladd Marsh Wildlife Area in northeast Oregon hosts a small group of nesting greater sandhill cranes (Grus canadensis tabida). There were no data on where these birds wintered, and we had no understanding of how these birds fit into the larger picture of western sandhill crane population delineation. ODFW began color-banding pre-fledging colts in 2007 and added satellite tracking with platform transmitter terminals (PTTs) in 2015. To date, we have captured 15 colts and 13 adults and marked them with color bands. We also fitted 1 colt and 8 adult cranes with PTTs. In fall 2015, all 3 PTT-marked birds traveled to wintering grounds in the Central Valley and Central Coast ecoregions of California. In fall 2016, of 5 PTT-marked cranes, 4 traveled to the Central Valley and Central Coast ecoregions of California. The fifth individual migrated south through Idaho and Nevada to the Lower Colorado River Valley. The PTT data from our study highlight the need for additional research on the validity of current western sandhill crane population divisions

Interactive effects between nest microclimate and nest vegetation structure confirm microclimate thresholds for Lesser Prairie-Chicken nest survival

Citation: Grisham, B. A., Godar, A. J., Boal, C. W., & Haukos, D. A. (2016). Interactive effects between nest microclimate and nest vegetation structure confirm microclimate thresholds for Lesser Prairie-Chicken nest survival. Condor, 118(4), 728-746. doi:10.1650/CONDOR-16-38.1The range of Lesser Prairie-Chickens (Tympanuchus pallidicinctus) spans 4 unique ecoregions along 2 distinct environmental gradients. The Sand Shinnery Oak Prairie ecoregion of the Southern High Plains of New Mexico and Texas is environmentally isolated, warmer, and more arid than the Short-Grass, Sand Sagebrush, and Mixed-Grass Prairie ecoregions in Colorado, Kansas, Oklahoma, and the northeast panhandle of Texas. Weather is known to influence Lesser Prairie-Chicken nest survival in the Sand Shinnery Oak Prairie ecoregion; regional variation may also influence nest microclimate and, ultimately, survival during incubation. To address this question, we placed data loggers adjacent to nests during incubation to quantify temperature and humidity distribution functions in 3 ecoregions. We developed a suite of a priori nest survival models that incorporated derived microclimate parameters and visual obstruction as covariates in Program MARK. We monitored 49 nests in Mixed-Grass, 22 nests in Sand Shinnery Oak, and 30 nests in Short-Grass ecoregions from 2010 to 2014. Our findings indicated that (1) the Sand Shinnery Oak Prairie ecoregion was hotter and drier during incubation than the Mixed- and Short-Grass ecoregions; (2) nest microclimate varied among years within ecoregions; (3) visual obstruction was positively associated with nest survival; but (4) daily nest survival probability decreased by 10% every half-hour when temperature was greater than 34°C and vapor pressure deficit was less than - 23 mmHg during the day (about 0600-2100 hours). Our major finding confirmed microclimate thresholds for nest survival under natural conditions across the species' distribution, although Lesser Prairie-Chickens are more likely to experience microclimate conditions that result in nest failures in the Sand Shinnery Oak Prairie ecoregion. The species would benefit from identification of thermal landscapes and management actions that promote cooler, more humid nest microclimates. © 2016 Cooper Ornithological Society

Non-overlapping Distributions of Feral Sheep (Ovis aries) and Stout Iguanas (Cyclura pinguis) on Guana Island, British Virgin Islands

Stout Iguanas (Cyclura pinguis) remain one of the most critically endangered reptiles in the world. Factors contributing to that status include habitat loss, predation by introduced species, and competition with introduced herbivores. On Guana Island, British Virgin Islands, the presence of feral sheep (Ovis aries) has been a hypothesized detriment to iguanas. Using motion sensitive cameras, we documented the distribution of feral sheep on Guana Island in 2010. We also quantified the impact of feral sheep on ground vegetation by comparing plant abundance at long term sheep exclosures and areas where sheep were absent to areas where sheep were present. Finally, we compared sheep distribution to iguana distribution on the island. The co-occurrence of sheep and Stout Iguanas was less than expected, indicating possible competition. Although we detected no difference in vegetative cover between areas where sheep were present and absent, the long-term exclosures showed that the exclusion of sheep allowed the abundance of many plant species to increase. Our data support the hypothesis that feral sheep are altering the abundance of ground-level vegetation and limiting iguana distribution on the island

AN UPDATED DISTRIBUTION MAP FOR THE LOWER COLORADO RIVER VALLEY POPULATION OF GREATER SANDHILL CRANES

The U.S. Fish and Wildlife Service (USFWS) recognizes 6 migratory populations of sandhill cranes (Grus canadensis) in the United States, 4 of which occur in or west of the Rocky Mountains. Traditionally the Lower Colorado River Valley Population (LCRVP; greater sandhill crane [G. c. tabida]) was thought to be distributed across the Imperial (California) and Lower Colorado River (Arizona) Valleys, southward into Mexico via the Colorado River delta in winter and northeastern Nevada (Elko and White Pine Counties) during summer. Conservation and management concern exists over known distribution based on winter and summer surveys because discrepancies exist between the number of individuals counted on winter and summer termini. In 2014 the USFWS initiated a mark-recapture program on the LCRVP to aid in the development of long-term management of this least abundant greater sandhill crane population. The objective of this paper is to update the known distribution of the LCRVP from greater sandhill cranes by using platform transmitter terminals (PTTs). We captured 44 individual greater sandhill cranes and equipped 22 with PTTs on the wintering and summering grounds in the Imperial and Lower Colorado River Valleys and west-central Idaho, 2014-2015. Our updated distribution map from 18 of 22 PTT-tagged individuals identified several new summer locations extending north and west into west-central Idaho and numerous new migratory locations extending east into Utah. We also confirmed winter locations on the Gila River southwest of Phoenix, Arizona. The extent of the distribution of the LCRVP extends farther north and east than previously expected and, most importantly, overlaps with areas commonly affiliated with the Central Valley and Rocky Mountain Populations in the Intermountain West

A Highly Contiguous and Annotated Genome Assembly of the Lesser Prairie-Chicken (Tympanuchus pallidicinctus)

Article asserts that the Lesser Prairie-Chicken (Tympanuchus pallidicinctus; LEPC) is an iconic North American prairie grouse, renowned for ornate and spectacular breeding season displays, a species that has been declining in population across much of its historical range, with corresponding precipitous declines in contemporary population abundance, largely due to climatic and anthropogenic factors. The authors describe an annotated reference genome that was generated from a LEPC sample collected from the southern DPS

Identifying the migratory strategy of the Lower Colorado River Valley population of Greater Sandhill Cranes

Across North America, Sandhill Cranes (Antigone canadensis) use an array of migratory strategies, ranging from “jumping,” or taking 1 or 2 flights from wintering grounds to a staging area, then on to the breeding grounds, to “hopping,” or taking shorter flights among multiple (\u3e3) staging areas between termini. We captured 16 adult and 2 juvenile Greater Sandhill Cranes (Antigone canadensis tabida) from the Lower Colorado River Valley population (LCRVP) and fitted them with platform transmitter terminals (PTTs) for GPS satellite telemetry. We used recorded locations and Brownian bridge movement models (BBMMs) to identify migration corridors and areas of migratory use (AMUs) during spring and fall migration (2014-2016). Eighty-nine percent of our sample (n = 16) of LCRVP Sandhill Cranes with PTTs flew direct paths between summer and winter termini. Starting in the Great Basin and moving into the Mojave Desert and then into the Sonoran Desert, the LCRVP aligned its migration with drainages, rivers, and reservoirs. Within those direct paths, we identified 18 unique and discrete AMUs along an ∼1000-km corridor and 3 within minor corridors taken by the other 2 cranes. We defined AMU as an area within a crane’s 75% BBMM migration confidence contour where the crane had 2 or more subsequent time stamps (could be ≥3 hours) and did not travel \u3e40 km from the first time stamp. The average migration duration was 23 days (spring, n = 3; fall, n = 2; cranes, n = 53). The fact that many individuals stopped several times after relatively short flights during both migration seasons suggests that the LCRVP generally uses a “hop” migration strategy. The use, often frequent and consecutive, of the 21 AMUs in this research reveals the potential importance of these migration areas to the LCRVP for its social, behavioral, and energetic requirements during migration

MIXING OF TWO GREATER SANDHILL CRANE POPULATIONS IN NORTHEAST OREGON

The Oregon Department of Fish and Wildlife (ODFW) Ladd Marsh Wildlife Area in northeast Oregon hosts a small group of nesting greater sandhill cranes (Grus canadensis tabida). There were no data on where these birds wintered, and we had no understanding of how these birds fit into the larger picture of western sandhill crane population delineation. ODFW began color-banding pre-fledging colts in 2007 and added satellite tracking with platform transmitter terminals (PTTs) in 2015. To date, we have captured 15 colts and 13 adults and marked them with color bands. We also fitted 1 colt and 8 adult cranes with PTTs. In fall 2015, all 3 PTT-marked birds traveled to wintering grounds in the Central Valley and Central Coast ecoregions of California. In fall 2016, of 5 PTT-marked cranes, 4 traveled to the Central Valley and Central Coast ecoregions of California. The fifth individual migrated south through Idaho and Nevada to the Lower Colorado River Valley. The PTT data from our study highlight the need for additional research on the validity of current western sandhill crane population divisions

AN UPDATED DISTRIBUTION MAP FOR THE LOWER COLORADO RIVER VALLEY POPULATION OF GREATER SANDHILL CRANES

The U.S. Fish and Wildlife Service (USFWS) recognizes 6 migratory populations of sandhill cranes (Grus canadensis) in the United States, 4 of which occur in or west of the Rocky Mountains. Traditionally the Lower Colorado River Valley Population (LCRVP; greater sandhill crane [G. c. tabida]) was thought to be distributed across the Imperial (California) and Lower Colorado River (Arizona) Valleys, southward into Mexico via the Colorado River delta in winter and northeastern Nevada (Elko and White Pine Counties) during summer. Conservation and management concern exists over known distribution based on winter and summer surveys because discrepancies exist between the number of individuals counted on winter and summer termini. In 2014 the USFWS initiated a mark-recapture program on the LCRVP to aid in the development of long-term management of this least abundant greater sandhill crane population. The objective of this paper is to update the known distribution of the LCRVP from greater sandhill cranes by using platform transmitter terminals (PTTs). We captured 44 individual greater sandhill cranes and equipped 22 with PTTs on the wintering and summering grounds in the Imperial and Lower Colorado River Valleys and west-central Idaho, 2014-2015. Our updated distribution map from 18 of 22 PTT-tagged individuals identified several new summer locations extending north and west into west-central Idaho and numerous new migratory locations extending east into Utah. We also confirmed winter locations on the Gila River southwest of Phoenix, Arizona. The extent of the distribution of the LCRVP extends farther north and east than previously expected and, most importantly, overlaps with areas commonly affiliated with the Central Valley and Rocky Mountain Populations in the Intermountain West