Zenaida Asiatica Research Articles

Spatial and temporal patterns of range expansion of white‐winged doves in the USA from 1979 to 2007

AbstractAimThe 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.LocationSouthern half of the USA.MethodsWe 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.ResultsOur 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 conclusionsEstimating 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.

Comparison of capture and escape rates between different types of portable cowbird traps

ABSTRACTControl of brown‐headed cowbirds (Molothrus ater) is often advocated to reduce parasitism and improve nesting success of sensitive populations of passerine birds, but little information is available in the literature concerning the relative effectiveness of different types of cowbird traps or the effects of these traps on non‐target species. We used portable traps to capture cowbirds in 2003–2007 at 3 study areas in southern Nevada and western Arizona. We compared the effectiveness of traps with flat tops versus funnel‐shaped tops in 2005 and compared entrance slots of 2 different widths in 2006–2007. Traps with funnel‐shaped tops had higher cowbird capture rates and lower escape rates than did flat‐topped traps. Funnel‐topped traps also had a higher capture rate of non‐target species. Funnel‐topped traps with a 3.8‐cm‐wide entrance slot had a higher capture rate for male cowbirds than did identical traps with a 3.2‐cm‐wide entrance slot. Capture rates for female cowbirds did not differ between slot sizes, nor did escape rates for either males or females. Capture rates for non‐target species did not differ between slot widths, but wider slots captured larger bodied species (e.g., white‐winged dove [Zenaida asiatica] and great‐tailed grackle [Quiscalus mexicanus]) that were not seen in the traps with narrower slots in the years when both slot widths were tested. Cowbird traps with a funnel‐topped design should be used to maximize the number of cowbirds captured and removed from a site. A slot width of 3.2 cm may minimize non‐target captures, particularly of larger bodied species, while still allowing effective removal of female cowbirds. © 2014 The Wildlife Society.

Pilot Study for Aging Classification Criteria of Fledged Juvenile Eastern White-winged Doves

Abstract Nineteen eastern white-winged doves Zenaida asiatica asiatica were hatched and raised in captivity and used to develop an aging key that 1) quickly identifies juveniles based on a series of morphological features, and 2) provides estimates of juvenile age based on primary feather replacement. Birds were photographed every three days from 17 to 170 d posthatch to determine sequence of primary flight feather replacement; persistence of juvenile secondary coverts; and development of blue eye ring, black neck bars, and leg color. Eleven birds exhibited adult features such as absence of buffy-tipped primary coverts, blue eye-ring color, complete black neck bar, and red leg color at day 170 posthatch; two birds had these features as early as day 122. Replacement of primary feathers was variable among individuals beyond day 35 beginning with the third primary. Primary feather (primary notation P1–P10) replacement occurred gradually. By day 170, 2 of 17 birds had replaced all primary feathers, 3 birds had fully molted P9 but not P10, 8 birds had begun molting P9 but not P10, and 4 birds did not molt either P9 or P10. Increased variability in primary feather replacement occurred as juveniles progressed toward adulthood; this precluded accurate age estimates of older juveniles based exclusively on primary replacement. The present study provides a better understanding of the molting process that wildlife managers, biologists, and researchers can use at hunter check stations or during trapping and banding operations to separate age classes, which is necessary to establish hunting frameworks and to assess the population effects of harvest and other mortality factors. This pilot study provides the foundation needed for further investigations into developmental patterns of fledged juvenile white-winged doves and provides an aging key that represents an improvement over previous white-winged dove aging keys or reliance on aging keys of closely related species.

Immigration and Recruitment in an Urban White-Winged Dove Breeding Colony

Abstract Dove population management necessitates estimates of vital rates for use in mechanistic models used to evaluate and predict population responses to environmental variation and/or alternative harvest scenarios. Estimating recruitment (number of juveniles per adult) is complicated because a compendium of factors drives production in doves. White-winged doves Zenaida asiatica exhibit a fairly unique breeding strategy wherein they commonly return to the same breeding area and reproduce in large breeding aggregations (i.e., colonies). We used an open-population capture–recapture model to estimate annual immigration and in situ recruitment of white-winged doves breeding in an urban colony during 2009 and 2010. We captured 5,101 unique white-winged doves in 2009 (2,894 after hatch year, 2,207 hatch year) and 3,502 unique white-winged doves in 2010 (3,106 after hatch year, 486 hatch year). Immigration of adults into the breeding colony peaked during late April and early May, with in situ recruitment occurring during a 6-wk period from 19 June to 30 July. Our results predicted that >90% of all hatch-year individuals had entered the local population by 1 August. The Jolly–Seber model used allows white-winged dove recruitment values to be estimated directly (rather than as a conglomerate of multiple parameters), separates immigration from in situ recruitment within a season, and can be useful for monitoring recruitment and evaluating alternative recruitment indices for future use in harvest management-planning actions.

Vector-Host Interactions of Culex pipiens Complex in Northeastern and Southwestern USA

Studies on the vector-host interactions of Culex pipiens complex mosquitoes by sequencing portions of mitochondrial cytochrome b gene indicate that Cx. p. pipiens f. pipiens predominantly feed on avian hosts (93.1%), and focus feeding activity on several key bird species, in particular the American robin, the gray catbird, and the house sparrow in Connecticut. However, Cx. p. quinquefasciatus indiscriminately feed on both birds and mammals. Culex p. quinquefasciatus in Harris County - Texas and southern California acquired 39.1% and 88.2% of bloodmeals from birds, respectively. Mammalian-derived bloodmeals constituted 52.5% and 9.6% in the two regions, respectively. The most frequent avian hosts for this mosquito species in the southwestern U.S. were the mourning dove, the white-winged dove, the house sparrow and the house finch. Humans infrequently served as the source of bloodmeals for Cx. p. pipiens and Cx. p. quinquefasciatus. Microsatellite analysis of mosquitoes from Chicago, Illinois showed that Cx. p. pipiens f. pipiens with mammalian- derived bloodmeals had significantly higher ancestry and proportion of hybrids from Cx. p. pipiens f. molestus than did those with avian-derived bloodmeals.

ESTUDIO SOBRE PELIGRO AVIARIO: ANÁLISIS DEL RIESGO DE IMPACTOS ENTRE AVES Y AERONAVES EN EL AEROPUERTO INTERNACIONAL AUGUSTO C. SANDINO, MANAGUA, NICARAGUA

El peligro aviario es el riesgo de coliciones entre aves y aeronaves. Para reducir ese peligro es necesario entender la naturaleza de las aves que habitan dentro y alrededor del aeropuerto y clasificarlas numericamente en base a la peligrosidad que representan, conociendo a la vez las estaciones del año, los meses del año, horas del día, condiciones climáticas, focos de atracción (cobertura, alimentación y agua) que incrementan la abundancia y la riqueza de aves en las áreas aeroportuarias. Para obtener la información se seleccionaron dos sitios de observación: uno en las áreas verdes alrededor de la pista de aterrizaje, con el objetivo de registrar las especies de aves hacen uso de este sitio permanente o temporalmente, y otro en la torre de control, para determinar rutas de aves de mayor peso, gregarias y de alto vuelo en un radio de 3000 m con centro en la torre de control. Las especies observadas con mayor frecuencia en la pista de aterrizaje fueron: Hirundo rustica, Quiscalus mexicanus, Molothrus aeneus, Columbina talpacoti y Columba livia. Desde la torre de control se observaron con mayor frecuencia: Coragyps atratus, Zenaida asiatica, Molotrus aeneus y Quiscalus mexicanus. En la pista de aterrizaje y desde la torre de control la abundancia y riqueza de aves no varió significativamente a lo largo de los meses del año. En la pista de aterrizaje la abundancia incrementa significativamente en el período seco en horarios de 06:00-07:00 am, principalmente por la presencia de Q. mexicanus y H. rustica. La riqueza en el periodo seco y la abundancia y riqueza en el período lluvioso no varió significativamente. Desde la torre de control no se registraron incrementos significativos de la abundancia y riqueza de aves en el período seco, pero si de la abundancia en el período lluvioso, con alzas a las 11:00 y 13:00, principalmente por la mayores actividades de la especie C. atratus a esas horas. La abundancia de aves en la pista de aterrizaje dependió de las condiciones climáticas, aumentando al aumentar la precipitación y la nubosidad y reduciéndose al aumentar la velocidad del viento y la temperatura. La actividad de las aves observadas desde la torre de control no varió significativamente con las variaciones climáticas diarias. Las especies que hacen mayor uso del enmallado perimetral del aeropuerto para perchar fueron: Passers domesticus, Columbina talpacoti, Tyrannus melancholicus, Crotophaga sulcirostris y Tyrannus forficatus. Los sitios preferidos para anidación dentro del aeropuerto fueron árboles de Almendra (Terminalia catapa), Mango (Manguifera indica) y dentro del las instalacones del cuerpo de Bomberos, torre de control y los hangares. Se concluye que C. atratus y Q. mexicanus son las especies que más peligro representan para la aviación, seguidas en menor escala de C. livia, C. talpocati, H. rustica y M. aeneus. Los sectores norte, oeste y una parte del sector sur del aeropuerto son áreas de mayor riesgo aviario por una mayor frecuencia de observación de C. atratus en esa zona. La especie Q. mexicanus esta distribuida principalmente en el sector sureste. Las fuentes de atracción para las aves van desde sitios ideales para hábitat, refugio, anidación y perchaje hasta fuente de alimentos que incluyen vegetales, insectos, vertebrados, basureros y mataderos. DOI: http://dx.doi.org/10.5377/calera.v11i16.750 La Calera Vol. 11, No 16 p. 33-42/junio 2011

A Comparison of White-Winged DoveZenaida asiaticaDensities Estimated During Morning and Evening Surveys

AbstractSurveying bird populations through visual observation is generally limited to morning. The focus on morning surveys is based on the reasonable assumption that detection is more likely when birds are most active. However, population surveys could become more time- and cost-efficient if both morning and evening sampling were equally effective, particularly for game birds, such as white-winged dove Zenaida asiatica. Texas Parks and Wildlife Department has recently implemented distance sampling to estimate population sizes and monitor an ongoing range expansion of this species. We compared morning vs. evening density estimates for white-winged doves sampled in Mason, Texas, on six separate occasions during summer 2006. Program DISTANCE (version 5.0) calculated similar detection probabilities and density estimates between paired morning and evening sampling periods. Probability of detection ranged from 0.27 to 0.46 for both morning and evening samples. Densities, in individuals/ha, ranged from 2.54 to 4.02 for morning sampling and 2.48 to 4.31 for evening sampling. In addition, variables (number of observations, cluster size, distance to cluster) used by DISTANCE did not vary substantially between morning and evening surveys. Our results suggest evening surveys are as effective as the conventional protocol of surveying white-winged doves only in the morning. Additional studies, using Program DISTANCE, should be conducted to similarly evaluate other species.

Distribution and derivation of white‐winged dove harvests in Texas

AbstractBand 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.

Survival, fidelity, and recovery rates of white‐winged doves in Texas

AbstractManagement 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.

The Effects of Range Expansion on the Population Genetics of White-Winged Doves in Texas

Abstract Species that undergo range expansions often exhibit a loss of genetic diversity in populations found at the leading edge of the expansion and show a genetic signal of isolation by distance. We examined the genetic consequences of range expansion on White-winged Dove populations, a species that is undergoing a range and possible demographic expansion in Texas. We genotyped five microsatellite loci and sequenced a segment of mitochondrial DNA and found that White-winged Doves do not exhibit a loss of genetic diversity in recently colonized areas or a genetic signal of a demographic expansion. However, we did find a slight signal of isolation by distance and range expansion based on both nuclear and mitochondrial markers. We suggest that high, multi-directional, ongoing gene flow has removed any loss of diversity caused by range expansion. A conservation implication of our findings is that species that exhibit rapid range expansions with high gene flow are likely to retain their evolutionary potenti...

Helminth Community Composition, Structure, and Pattern in Six Dove Species (Columbiformes: Columbidae) of South Texas

The helminth community composition and structure of 6 species of columbids residing in south Texas are reported and compared herein. Sixty individuals of the following species, rock pigeons (Columba livia [RP]), mourning doves (Zenaida macroura [MD]), Eurasian collared-doves (Streptopelia decaocto [ECD]), white-winged doves (Zenaida asiatica [WWD]), and common ground doves (Columbina passerina [CGD]), and 48 Inca doves (Columbina inca [ID]) were collected during the summer of 2006 and examined for helminths. Twelve helminth species were found (9 nematodes and 3 cestodes), representing 486 individuals. Nematodes numerically dominated the component community in all host species. Overall, helminth prevalence was similar among host sex within all dove species. However, prevalence of Skrjabinia bonini and Hymenolepis sp. in RPs was significantly different among host age groups (P = 0.01, P = 0.0002, respectively). Likewise, prevalence of Killigrewia delafondi was higher (P = 0.0001) in adult WWDs. Based on percent similarity and Jaccard's coefficient of community indices, helminth component communities were dissimilar, and the number of shared helminth species varied among host species. Data from this study suggest that the environment surrounding preferred host habitat and foraging strategies of each host species is the driving force behind helminth component communities. This study emphasizes the importance of examining co-occurring hosts at both local and regional scales to elucidate helminth community structure and patterns.

The effect of habitat on the range expansion of a native and an introduced bird species

Aim 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. Location Continental USA. Methods 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. Results 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. Main conclusions 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.

Dove Habitat Association Based on Remotely Sensed Land Cover Types in South Texas

We tested whether presence of white-winged doves (Zenaida asiatica) and mourning doves (Z. macroura) in South Texas, USA, was associated with any of the land cover types recorded in the 2001 National Land Classification Database. We used the point-transect method to conduct presence–absence surveys for both species at 236 points encompassing 744 observations. Within predefined land cover types surrounding each survey point, we used Geographic Information Systems to determine the proportions of each land cover type present. We used randomization tests to compare proportions of land cover types present at points with and without doves. We used Program DISTANCE to estimate dove densities at survey points and to test whether certain land cover types were associated with greater dove densities. Our results indicated white-winged dove occurrence in South Texas was positively associated with urban land and cropland, whereas mourning dove occurrence was positively associated with cropland. For land cover types found to be associated with dove presence, estimated density for each dove species increased as the proportion of associated land cover type increased. These results can assist wildlife biologists in the development of a more efficient and targeted protocol for censusing doves. In addition, our methods can be applied to other species across several geographic areas and landscape scales.

Dove Habitat Association Based on Remotely Sensed Land Cover Types in South Texas

Abstract: We tested whether presence of white‐winged doves (Zenaida asiatica) and mourning doves (Z. macroura) in South Texas, USA, was associated with any of the land cover types recorded in the 2001 National Land Classification Database. We used the point‐transect method to conduct presence—absence surveys for both species at 236 points encompassing 744 observations. Within predefined land cover types surrounding each survey point, we used Geographic Information Systems to determine the proportions of each land cover type present. We used randomization tests to compare proportions of land cover types present at points with and without doves. We used Program DISTANCE to estimate dove densities at survey points and to test whether certain land cover types were associated with greater dove densities. Our results indicated white‐winged dove occurrence in South Texas was positively associated with urban land and cropland, whereas mourning dove occurrence was positively associated with cropland. For land cover types found to be associated with dove presence, estimated density for each dove species increased as the proportion of associated land cover type increased. These results can assist wildlife biologists in the development of a more efficient and targeted protocol for censusing doves. In addition, our methods can be applied to other species across several geographic areas and landscape scales.

Lead Concentrations of White-winged Doves, Zenaida asiatica L., Collected in the Lower Rio Grande Valley of Texas, USA

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 microg/g dry weight and ranged from ND to 11.01 microg/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.

Effects of habitat type on bird nesting in the desert grasslands of central Mexico: conservation implications

AbstractPopulations of North American grassland birds have suffered drastic declines. The causes of these declines are only partially understood and may vary among regions. During the 2004 and 2005 breeding seasons we recorded survival information from 220 nests of four bird species in nine study sites representing three habitat types of the desert grasslands of central Mexico, where grassland birds had not yet been studied. We predicted that land-use change from shortgrass steppe to heavily grazed savannah-type grasslands and agriculture would negatively affect nesting success, number of fledglings and nest abundance. We also examined temporal effects on reproductive success. We found some evidence that nest survival of savannah sparrowsPasserculus sandwichensis, loggerhead shrikesLanius ludovicianusand white-winged dovesZenaida asiaticavaried with date, and that nest survival of the dove was lowest in agricultural sites. However, confidence intervals were large, suggesting that other variables were also important. Whereas white-winged dove nests were notably more abundant in agricultural areas compared to the other habitat types, western meadowlarkSturnella neglectanests were not found in agricultural areas. Ploughing caused the largest proportion of nest failures in agricultural areas and, on average, all species fledged fewer young per nest in agricultural areas. Therefore, minimizing agriculture and adjusting harvest times could enhance conservation of grassland-nesting birds in central Mexico. Our study also suggests that inter-annual variation in rainfall can change the onset of nesting by at least 2 months.

Evaluation of a New Technique for Determining Sex of Adult White-Winged Doves (Zenaida asiatica)

Abstract Previous studies have shown that determining sex of adult white-winged doves (Zenaida asiatica) by cloacal characteristics is highly reliable (90%), while using plumage characteristics and body weights are less so. The drawback of the cloacal technique is that the procedure requires use of a modified nasal speculum to probe the cloacal area, which could possibly cause injury to the bird. We hypothesized that females have a wider pelvis than males for the passage of eggs, which should be quantifiable, thereby providing a means of separating adult males and females. We measured pelvic spread (distance from tip to tip of pelvis) of adults (n = 249). Additionally, body masses were taken for a subset (n = 215) of the doves. Sex was positively determined by either cloacal examination of live birds or gonad examination of dead birds. Mean pelvic spread of males was significantly less than that of females. Whole body mass was not correlated with pelvic spread for either sex. Accuracy of the pelvic sp...

Home Ranges of Two Populations of Urban-Nesting White-Winged Doves (Zenaida asiatica) in Texas

Our objective was to use the 50%-core-area estimation to measure size of home range of urban-breeding white-winged doves (Zenaida asiatica) from two ecoregions in Texas. We collected data on locations using subcutaneously implanted radiotransmitters on 40 white-winged doves in Kingsville, Kleberg County, during 2000, and 40 and 39 white-winged doves in Waco, McLellan County, during 2002 and 2003, respectively. We calculated size of home ranges using bivariate-normal methods. We compared size of home range from 50%-core-area estimations within and between sites, and by sex, using two-sample t-tests following log10 transformation of data to meet the assumptions of normality and homoscedasticity. Generally, estimated size of 50%-core-areas differed significantly between sites but not within sites.

Seroprevalence of antibodies against Salmonella enterica subsp. enterica serovar Gallinarum-Pullorum in wild doves ( Zenaida asiatica and Zenaida macroura) from the Northeast of Mexico

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.

Status of White-Winged Dove Nesting Colonies in Tamaulipas, México

The core of eastern White-winged Dove (Zenaida asiatica asiatica) breeding habitat historically occurred in northern México and southern Texas. Much nesting-habitat loss has occurred in this region since the mid-1900s and several large nesting colonies of the historic complex have disappeared with others currently at risk. Little knowledge exists regarding the precise location of these colonies or their current status. We reviewed the literature, interviewed biologists, and conducted site visits to Tamaulipas, México during May– August 2004 and 2005 to construct a historical account of White-winged Dove colonies. We found references to 77 possible nesting colonies thought to exist over a 50-year period in Tamaulipas. However, 26 references represented alternative names for the same colonies resulting in 51 colonies. We located 31 of these colonies of which 13 were active and 18 were inactive. The remaining 20 were not described in sufficient detail to locate. Brush clearing was listed as a cause for 78% of the 18 inactive colonies followed by weather catastrophes (56%) and overharvest (39%). Collectively, these 3 factors appeared to be responsible for 94% of all colony loss. The historic, large colonies of the past are gone and likely will not return because of these factors, primarily because of brush clearing.