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Objective: To evaluate the response of CAT, AChE, and GST enzyme biomarkers in Zenaida asiatica from an agricultural area of the municipality of Champotón, Campeche. Design/methodology/approach: The biomarkers AChE, CAT, and GST were analyzed in tissues of 24 birds from backyards and agricultural areas of Champotón, Campeche. The enzymatic activities in the tissues were compared by means of a t test and comparison of means (Tukey p≤0.05), with the Statistica v. 7 software. Results: The highest AChE activity occurred in the brain (p=0.00001), CAT activity in liver (p=0.00001), and GST activity in liver and brain (p=0.001). Study limitations/implications: To evaluate the effect of pesticides on wild birds, a larger number of individuals is required in different agricultural areas. Findings/conclusions: In the tissues of Z. asiatica from agricultural areas, greater activity of the biomarkers AChE, CAT, and GST was found, reflecting the excessive use of pesticides. [ABSTRACT FROM AUTHOR]

The simultaneous study of demography and behavior might provide a more comprehensive understanding about animal responses to anthropogenic disturbances. The White-winged Dove (Zenaida asiatica) is a frequent dweller of urban and agricultural habitats in North America, Central America, and the Caribbean. Still, research on the species is heavily biased to the USA. We analyzed the response of the species to human disturbances during winter across an urban-agricultural landscape in northwestern Mexico through a demographic and behavioral approach. We modeled the effect of disturbance types (pedestrians, cars, pavement and building cover) on the density of the species. Also, we investigated if surveillance behavior varied across the landscape by estimating and comparing perching proportion among land uses (urban grey areas, urban green areas, cropfields, shrublands). We did not detect the species within cropfields, possibly because food resources were not available for the dove during winter in this land use. Pavement cover limited species’ density, as it might reduce the surface of the preferred feeding substrates of the dove. Pedestrians and building cover increased the density of the species, as they might provide food and shelter for the dove, respectively. Surveillance behavior peaked in urban grey areas, whereas it dropped in urban green areas. Differences on threat levels, threat type, and protective cover among land uses might influence such behavioral pattern. Our approach contributes to the knowledge of the species and demonstrates that both demographic and behavioral cues provide complementary evidence for analyzing the impact of human disturbances on animals.

Wildlife-aircraft strikes threaten both human and animal safety and result in hundreds of millions of dollars per year in aircraft damage and lost flight hours. Large-bodied birds are especially hazardous to aircraft. However, given high-speed flight at low altitudes, military aircraft may be especially vulnerable to strikes and more susceptible to damage even when encountering small birds. We summarized all wildlife-aircraft strike records from Randolph Air Force Base (San Antonio, Texas) over a 25-year period and compared the number and cost of strikes across avian species and species groups. Because columbids (i.e., pigeons and doves) are among the most frequently struck species by both civilian and military aircraft and because several columbid species have demonstrated marked population increases over the past decade, we also quantified characteristics (i.e., month, time of day, precipitation patterns, phase of flight, altitude) of columbid strikes. White-winged doves (Zenaida asiatica) have undergone a substantial northward range expansion over the past 60 years and are now numerous in San Antonio. Given local interest, we also highlighted characteristics of aircraft strikes involving this species. Though columbids were not the most frequently struck species group during the survey period (1990–2014), they were the most costly. Columbid strikes were more frequent from May to July than during other months and often occurred during morning hours, especially from 08:00–10:00, with a smaller afternoon peak from 15:00–17:00. Columbid strikes occurred during landing more than during other phases of flight, typically at ≤152 m above ground level (AGL), though white-winged doves were more likely to be struck on takeoff than expected. To reduce costs and safety concerns where columbids are prevalent, military flight planners, aircrews, and wildlife managers can reduce air travel, increase vigilance during takeoffs and landings, and implement on-the-ground hazing techniques in morning and late afternoon hours during spring and summer months.

Wildlife.aircraft strikes threaten both human and animal safety and result in hundreds of millions of dollars per year in aircraft damage and lost flight hours. Large-bodied birds are especially hazardous to aircraft. However, given high-speed flight at low altitudes, military aircraft may be especially vulnerable to strikes and more susceptible to damage even when encountering small birds. We summarized all wildlife.aircraft strike records from Randolph Air Force Base (San Antonio, Texas, USA) over a 25-year period and compared the number and cost of strikes across avian species and species groups. Because columbids (i.e., pigeons and doves) are among the most frequently struck species by both civilian and military aircraft and because several columbid species have demonstrated marked population increases over the past decade, we also quantified characteristics (i.e., month, time of day, precipitation patterns, phase of flight, altitude) of columbid strikes. White-winged doves (Zenaida asiatica) have undergone a substantial northward range expansion over the past 60 years and are now numerous in San Antonio. Given local interest, we also highlighted characteristics of aircraft strikes involving this species. Though columbids were not the most frequently struck species group during the survey period (1990.2014), they were the most costly. Columbid strikes were more frequent from May to July than during other months and often occurred during morning hours, especially from 0800.1000 hours, with a smaller afternoon peak from 1500.1700 hours. Columbid strikes occurred during landing more often than during other phases of flight, typically at ≤152 m above ground level (AGL), though white-winged doves were more likely to be struck on takeoff than expected. To reduce costs and safety concerns where columbids are prevalent, military flight planners, aircrews, and wildlife managers can reduce air travel, increase vigilance during takeoffs and landings, and implement on-the-ground hazing techniques in morning and late afternoon hours during spring and summer months. [ABSTRACT FROM AUTHOR]

ABSTRACT The white-winged dove ( Zenaida asiatica) serves an important ecological role as a diurnal pollinator of the saguaro cactus in the Sonoran desert and an economic role as a highly sought after game bird in North America. White-winged doves are intimately linked to anthropogenic changes on the landscape and because of this, have experienced dramatic population fluctuations over the last 75 years in response, both positively and negatively, to anthropogenic changes on the landscape. To understand the factors driving population growth and decline of migratory species like the white-winged dove, it is imperative we study resource use on both their breeding and wintering grounds. To understand how populations are distributed on the wintering grounds, we tested an alternative to band recovery approaches by using stable isotope analysis. Before we could use isotope analysis to link breeding and wintering locations for this species, we first needed to determine if hydrogen (δ2H) and carbon (δ13C) stable isotopes in feather tissue (δ2Hf and δ13Cf, respectively) could differentiate among populations of white-winged doves across their breeding range in Texas, New Mexico, and Arizona. δ2Hf and δ13Cf not only differentiated between populations of white-winged doves that breed in the United States, but δ2Hf also provided further differentiation in white-winged doves that breed in native Sonoran Desert and agricultural habitats in the western portion of their range. Ecological processes associated with desert resources and anthropogenic influences, specifically saguaro cacti and irrigated crops, largely determined δ2Hf in some white-winged doves in Arizona whereas δ2H of precipitation (δ2Hp) largely determined δ2Hf of doves in New Mexico and Texas. This study highlights the usefulness of stable isotope analysis to differentiate populations of animals across the landscape and the insight isotopes can provide into habitat and resource use. Published 2015. This article is a U.S. Government work and is in the public domain in the USA. [ABSTRACT FROM AUTHOR]

Aim The geographical expansion of white-winged doves ( Zenaida asiatica) in North America has attracted the attention of biologists and sportsmen because of their recreational and aesthetic value; however, data on factors driving the spatial spread of this species are lacking. We examined spatial and temporal patterns of range expansion for white-winged doves along the northern edge of their geographical range from 1979 to 2007 and used a dynamic occupancy model to estimate when and where doves would be found along an expansion gradient. Location Southern half of the USA. Methods We modelled spatial variation in the range expansion of white-winged doves from 1979 to 2007 using data from the North American Breeding Bird Surveys ( BBS) and distance from initial population centre, area of urban land cover, and ecoregion. We used a robust design occupancy analysis to estimate species expansion rate based on a model set grounded in broad-scale conditions likely to drive dove distribution. We evaluated our best fitting model (using Akaike's information criterion adjusted for small sample size) by comparing estimates to actual observations in 1993 and 2007 using area under the curve ( AUC) metrics from receiver-operating characteristic plots. Results Our spatial distribution model indicated that range expansion of white-winged doves was primarily influenced by distance from the core population centre, with additive effects of ecoregion and land cover. In 1979, white-winged doves were present in 12% of survey locations, whereas presence increased to 41% by 2007. Across all ecoregions, urban land cover was positively related to probability of occupancy. We evaluated our model for 1993 and 2007 by comparing derived occupancy estimates to sightings of white-winged doves within our sample hexagons using BBS survey data. Based on high AUC statistics (> 0.85), we concluded that our model was useful for accurately predicting range expansion. Main conclusions Estimating occurrence and range expansion of white-winged doves and other expanding/invasive avian species at large spatial scales can be effectively conducted using BBS data. Using these nationwide, long-term survey data to relate expansion to a suite of conditions likely to drive population dynamics is an effective approach to developing predictive models of range expansion. [ABSTRACT FROM AUTHOR]

Management of migratory birds at the national level has historically relied on regulatory boundaries for definition of harvest restrictions and estimation of demographic parameters. Most species of migratory game birds are not expanding their ranges, so migratory corridors are approximately fixed. White-winged doves ( Zenaida asiatica), however, have undergone significant variation in population structure with marked range expansion occurring in Texas, and range contraction in Arizona, during the last 30 years. Because >85% of white-winged dove harvest in the United States (approx. 1.3 million annually) now occurs in Texas, information on vital rates of expanding white-winged dove populations is necessary for informed management. We used band recovery and mark-recapture data to investigate variation in survival and harvest across 3 geographic strata for white-winged doves banded in the pre-hunting season in Texas during 2007-2010. We banded 60,742 white-winged doves, recovered 2,458 bands via harvest reporting, and recaptured 455 known-age birds between 2007 and 2010. The best supporting model found some evidence for geographic differences in survival rates among strata (A-C) in both hatch-year (juvenile; A = 0.205 [SE = 0.0476], B = 0.213 [SE = 0.0278], C = 0.364 [SE = 0.0254]) and after-hatch year (adult; A = 0.483 [SE = 0.0775], B = 0.465 [SE = 0.0366], C = 0.538 [SE = 0.251]) birds. White-winged doves had a low probability of moving among strata (0.009) or being recaptured (0.002) across all strata. Harvest recovery rates were concordant with estimates for other dove species, but were variable across geographic strata. Based on our results, harvest management strategies for white-winged doves in Texas and elsewhere should consider differences in population vital rates among geographic strata. © 2012 The Wildlife Society. [ABSTRACT FROM AUTHOR]

Band recoveries provide requisite data for evaluating the spatial distribution of harvest relative to the distribution of breeding stocks for a wide variety of migratory species. We used direct and indirect band-recovery data to evaluate the distribution and derivation of harvest of white-winged doves ( Zenaida asiatica) banded before hunting season in 3 distinct strata in Texas, USA, during 2007-2010. We banded 60,742 white-winged doves during 2007-2010, and based on 2,458 harvest recoveries, the majority (>95%) of white-winged dove harvest occurred during the first 2 months of the hunting season (Sep-Oct). Juvenile white-winged doves represented a greater percentage of the direct recoveries than adults across all strata (north = 80%, central = 69%, south = 82%) and the majority of direct band recoveries (north = 75%, central = 90%, south = 78%) occurred within the original banding strata. Age-specific weighting factors and harvest derivation indicated that both juvenile and adult harvest were highest within the strata of original banding. Harvest distribution data corrected for band-reporting rates indicated high fidelity of white-winged doves to specific geographic strata, with little interplay between strata. Our results suggest that population vital-rate estimates for survival and harvest for use in future Adaptive Harvest Management should focus on stock-specific levels. © 2012 The Wildlife Society. [ABSTRACT FROM AUTHOR]

Range expansion across a heterogeneous landscape may depend on the habitat selected and used by the expanding species. If habitat selection influences range expansion then localities colonized by a species should contain a greater proportion of favoured habitat (and less non-habitat) than other nearby localities not colonized. White-winged doves ( Zenaida asiatica) and Eurasian collared doves ( Streptopelia decaocto) are two bird species that provide an excellent opportunity to test this hypothesis, because the geographic ranges of both species have been expanding in North America for more than two decades. Continental USA. We used distribution data from the North American Breeding Bird Survey to test whether the landscapes occupied by each species contained a greater proportion of favoured habitat (urban land, grassland/pasture, shrub land and cropland) and a lower proportion of non-habitat (forest land) than landscapes where doves were not found. We tested each species separately in each of three broad expansion areas, namely East, Central and West. We also compared rates of spatial spread between expansion areas and between the two species. As predicted, both species tended to occupy landscapes with greater proportions of urban land, shrub land and cropland but with less forest land compared with landscapes without doves, in all three expansion areas. Contrary to prediction, occupied landscapes tended to have slightly less grassland/pasture than unoccupied landscapes. Rates of spread differed between the two species and among expansion areas. Range expansion and the extent to which a species fills or saturates its range are influenced by the habitat ecology of the expanding species. Species colonize localities based on the availability of suitable habitat. However, the role of habitat in a species' range expansion does depend somewhat on the greater geographical setting. Over large regional and geographical scales, range expansion (rate of spread and saturation) may proceed unevenly, suggesting that range expansion is a very dynamic and context-specific process. [ABSTRACT FROM AUTHOR]

White-winged dove ( Zenaida asiatica L.) exposure to environmentally accessible lead is a management concern. Detectable concentrations of lead were found in 142 (66%) of 214 white-winged doves collected in 2002 and 2003 at two wildlife management units in South Texas. Mean ± SD lead concentration was 0.70 ± 1.10 μg/g dry weight and ranged from ND to 11.01 μg/g dw. Lead concentrations were significantly lower in the 2002 samples, but similar between management units, age, and gender. White-winged doves in South Texas are being exposed to lead in the environment with some reaching subclinical to toxic levels. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Caribbean Ornithology is the property of Society for the Conservation & Study of Caribbean Birds and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Agricultural intensification is a key factor in the decline of many avian populations throughout the world, yet the exact mechanisms that contribute to these declines are relatively unresolved, especially for seed-eating species. We tested the hypothesis that forage quality, particularly protein content, limits productivity in birds consuming diets dominated by agricultural grains and lacking in native forages. We used white-winged doves (Zenaida asiatica) because columbids are highly granivorous and white-winged doves have declined in areas dominated by grain agriculture. We randomly assigned 52 pairs of captive doves to 1 of 2 treatments: we fed one treatment sorghum (Sorghum bicolor) and the second sorghum plus native seeds (croton [Croton sp.] and native sunflower [Helianthus sp.]). Birds with access to native seeds fledged 123%more young per pair, with young weighing 32%more at fledging than those fed only sorghum. Doves with access to native seeds selected a diet consisting of 43% sorghum, 32% croton, and 25% sunflower. We conclude that agricultural grains, which typically have high metabolizable energy and low to moderate protein concentrations, are not sufficient for normal productivity of white-winged doves. The lack of native forages with sufficient metabolizable energy and protein content may be a factor in the declining productivity of white-winged doves in the lower Rio Grande Valley of Texas, USA, as well as other species in regions dominated by agriculture. [ABSTRACT FROM AUTHOR]

Abstract: We present a simulation model for risk assessment of the impact of insecticide inhibitors of cholinesterase (ChE) applied in irrigated agricultural fields on non-target wildlife. The model, which we developed as a compartment model based on difference equations (Δt =1h), consists of six submodels describing the dynamics of (1) insecticide application, (2) insecticide movement into floodable soil, (3) irrigation and rain, (4) insecticide dissolution in water, (5) foraging and insecticide intake from water, and (6) ChE inhibition and recovery. To demonstrate application of the model, we simulated historical and “worst-case” scenarios of the impact of ChE-inhibiting insecticides on white-winged doves (Zenaida asiatica) inhabiting natural brushland adjacent to cotton and sugarcane fields in the Lower Rio Grande Valley of Texas, USA. Only when a rain event occurred just after insecticide application did predicted levels of ChE inhibition surpass the diagnostic level of 20% exposure. The present model should aid in assessing the effect of ChE-inhibiting insecticides on ChE activity of different species that drink contaminated water from irrigated agricultural fields, and in identifying specific situations in which the juxtaposition of environmental conditions and management schemes could result in a high risk to non-target wildlife. [Copyright &y& Elsevier]

We evaluated an unverified index (auditory counts) used to estimate breeding populations of white-winged doves (Zenaida asiatica) in Texas, USA, Our objectives were to determine optimal survey time of day, year, and count duration, determine it a relationship existed between number of calling doves and population size (nest and dove density), and evaluate an electronic counter to estimate breeding density. We collected data on 15 sites in the Lower Rio Grande Valley of Texas during May-August of 2002-2003. Peak calling occurred between mid-May and late June during 0600-0800 hours. We detected about 60% of calling doves during 2-minute auditory counts. Estimates of breeding doves (pairs ha-1) as determined by auditory counts were positively correlated with both population density (r > 0.90, P < 0.01) and nest density (r > 0.94, P < 0.01). The electronic coo-counter tally also exhibited a positive relationship with population density (r > 0.77, P < 0.01) and nest density (r > 0.92, P < 0.04). However, the high correlations observed for auditory counts and electronic counter were influenced by 2 high dove-density sites. Our data did not provide convincing support for the premise underlying auditory counts of white-winged doves (i.e., number of doves calling reflects dove abundance). The electronic coo counter was limited in application because it tabulated dove calls based solely on acoustic frequency and therefore could not discriminate against other avian calls with acoustic frequencies similar to those of white-winged doves. Auditory counts may be appropriate as coarse-resolution reconnaissance surveys to locate new white-winged dove areas in need of monitoring but not to obtain reliable abundance estimates. The use of an electronic counter to estimate breeding populations of white-winged doves holds promise, given technical modifications, and warrants further research. Given the current limitations of both auditory counts and electronic counters, alternative survey methods that incorporate detection probabilities (e.g., distance sampling) need to be evaluated for white-winged doves. [ABSTRACT FROM AUTHOR]

We respond here to a critique of our paper (Small et al. 2004b) regarding the methodology used to implant subcutaneous transmitters in white-winged doves (Zenaida asiatica). We agree with Mulcahy (2006) that more information regarding the methodology we used would have been appropriate. However, we refute the contention that we could not have followed the surgical protocol we cited and that protocols were not sterile. We believe this misinterpretation of our methods comes from a failure to note some of the finer points reported in our methodology. We address each issue made by Mulcahy (2006) in this response. [ABSTRACT FROM AUTHOR]

We experimentally evaluated alternative techniques of attaching radiotransmitters to captive white-winged doves (Zenaida asiatica) in Kingsville, Texas during 1998. Our evaluation consisted of monitoring physiological, pathological, and behavioral parameters in doves subjected to 6 radiotransmitter attachments (backpack harnesses, adhesive, subcutaneous implants, intracoelomic implants, subcutaneous surgeries without implantation, intracoelomic surgeries without implantation). We analyzed physiological parameters across 2 pretreatment and 4 post-treatment periods using a model-selection approach of mixed-effect models. Birds did not differ in physiological variables among treatment groups and a control. Time-activity budgets analyzed using nonparametric Friedman's tests did not differ in any activity category among treatment groups and a control. Subcutaneous implants were the most effective method of attachment based on retention rates, lack of mechanical difficulties associated with external attachment techniques, and minimum levels of pathology reported following necropsies. [ABSTRACT FROM AUTHOR]

The carbon isotope composition of an animal’s breath reveals the composition of the nutrients that it catabolizes for energy. Here we describe the use of Keeling plots, a method widely applied in ecosystem ecology, to measure the δ13C of respired CO2 of small vertebrates. We measured the δ13C of Rufous Hummingbirds (Selasphorus rufus) in the laboratory and of Mourning (Zenaida macroura) and White-winged (Z. asiatica) Doves in the field. In the laboratory, when hummingbirds were fed a sucrose based C3 diet, the δ13C of respired CO2 was not significantly different from that of their diet (δ13CC3 diet). The δ13C of respired CO2 for C3 fasted birds was slightly, albeit significantly, depleted in δ13C relative to δ13CC3 diet. Six hours after birds were shifted to a sucrose based C4 diet, the isotopic composition of their breath revealed that birds were catabolizing a mixture of nutrients derived from both the C3 and the C4 diet. In the field, the δ13C of respired CO2 from Mourning and White-winged Doves reflected that of their diets: the CAM saguaro cactus (Carnegeia gigantea) and C3 seeds, respectively. Keeling plots are an easy, effective and inexpensive method to measure δ13C of respired CO2 in the lab and the field. [ABSTRACT FROM AUTHOR]

The simultaneous study of demography and behavior might provide a more comprehensive understanding about animal responses to anthropogenic disturbances. The White-winged Dove (Zenaida asiatica) is a frequent dweller of urban and agricultural habitats in North America, Central America, and the Caribbean. Still, research on the species is heavily biased to the USA. We analyzed the response of the species to human disturbances during winter across an urban-agricultural landscape in northwestern Mexico through a demographic and behavioral approach. We modeled the effect of disturbance types (pedestrians, cars, pavement and building cover) on the density of the species. Also, we investigated if surveillance behavior varied across the landscape by estimating and comparing perching proportion among land uses (urban grey areas, urban green areas, cropfields, shrublands). We did not detect the species within cropfields, possibly because food resources were not available for the dove during winter in this land use. Pavement cover limited species' density, as it might reduce the surface of the preferred feeding substrates of the dove. Pedestrians and building cover increased the density of the species, as they might provide food and shelter for the dove, respectively. Surveillance behavior peaked in urban grey areas, whereas it dropped in urban green areas. Differences on threat levels, threat type, and protective cover among land uses might influence such behavioral pattern. Our approach contributes to the knowledge of the species and demonstrates that both demographic and behavioral cues provide complementary evidence for analyzing the impact of human disturbances on animals. [ABSTRACT FROM AUTHOR]

Abstract: A cross-sectional survey was conducted in order to determine the seroprevalence and to identify some factors associated with the presence of antibodies against Salmonella enterica subsp. enterica serovar Gallinarum-Pullorum in white-winged (Zenaida asiatica) and mourning doves (Zenaida macroura) from hunting areas of Northeast Mexico. From September to October 2006, 201 serum samples were analyzed with the seroagglutination test. The overall seroprevalence of S. enterica subsp. enterica serovar Gallinarum-Pullorum was 26.3%, and was similar for white-winged doves (26.4%) and mourning doves (26.1%), but higher for juveniles (30.8%) and females (34.6%). Seroprevalence was associated with the weight of the doves (prevalence ratio [PR]=1.52, P <0.0001) and the municipality where the doves were hunted (PR=1.31, P <0.0001). This survey study emphasizes the need to conduct similar studies on wild birds to determine the risk of S. enterica subsp. enterica serovar Gallinarum-Pullorum to commercial flocks. In addition, to the best of our knowledge this is the first report of the serological evidence suggesting infection with S. enterica subsp. enterica serovar Gallinarum-Pullorum in wild white-winged and mourning doves. [Copyright &y& Elsevier]

Copyright of Journal of Caribbean Ornithology is the property of Society for the Conservation & Study of Caribbean Birds and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)