Reproductivity and reising of Greater Rhea (Rhea americana) and Lesser Rhea (Pterocnemia pennata). A review

The Greater or Common Rhea (Rhea americana) and theLesser or Darwin’s Rhea (Pterocnemia pennata) are flight-less birds native from South America, that have conserva-tion and economic importance. Free-ranging populationsof these ratites have been detrimentally affected by humanactivities (BucherandNores, 1988;Carman, 1988;Martellaet al., 2000). On the other hand, during the1990s the farming of ratites, including rheas, experimenteda boom-and-bust process in USA, Canada and some Eur-opean countries (ChapmanandBass, 1994;Nara, 1994a;DeemingandAngel, 1996;Carbajoet al., 1997;Castel-lo ́, 1998a;Dey, 1998;GillespieandSchupp, 1998).Fil: Navarro, Joaquin Luis. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Zoología Aplicada; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Diversidad y Ecología Animal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Diversidad y Ecología Animal; ArgentinaFil: Martella, Monica Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Diversidad y Ecología Animal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Diversidad y Ecología Animal; Argentina. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Zoología Aplicada; Argentin

Efectos de los atributos de la hembra de ñandú (Rhea americana) sobre la viabilidad del huevo

We conducted a study throughout a breeding season in a captive-bred population of Greater rheas (Rhea americana) to evaluate the association between egg viability and the female´s body weight and age. A total of 180 eggs laid by 15 females of three age classes (5 individuals per class) were collected, individually identified, and their morphometric traits, fertility and hatchability were registered. Egg fertility increased with female´s age but was unaffected by female weight. Hatching rate does not correlate with maternal attributes. The current paper contributes towards understanding the role of certain maternal attributes in egg viability. Our findings suggest that breeding Greater rheas in large flocks where free mating occurs, increases the expression of natural sexual behavior and enhances the productivity and welfare of the birds.Realizamos un estudio a lo largo de una temporada reproductiva en una población de Ñandú común (Rhea americana) en cautiverio, con el fin de evaluar la asociación entre la viabilidad del huevo y el peso corporal y la edad de la hembra. Se colectaron un total de 180 huevos depositados por 15 hembras de tres clases de edad (5 individuos por clase). Cada huevo se identificó y se registraron sus características morfométricas, su fertilidad y éxito de eclosión. La fertilidad de los huevos se incrementó con la edad de la hembra que lo produjo pero no fue afectado por el peso corporal de la misma. La tasa de eclosión no se correlacionó con los atributos maternos evaluados. El presente trabajo contribuye a comprender el rol de ciertos atributos maternos en la viabilidad del huevo. Nuestros hallazgos sugieren que la cría de ñandúes en grandes grupos, donde el libre apareamiento es posible, aumentaría la expresión de un comportamiento sexual natural mejorando la productividad y el bienestar de las avesFil: Lábaque, María Carla. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones Biológicas y Tecnológicas. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Instituto de Investigaciones Biológicas y Tecnológicas; Argentina. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Departamento de Diversidad Biológica y Ecológica. Cátedra de Ecología; ArgentinaFil: Martella, Monica Beatriz. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Departamento de Diversidad Biológica y Ecológica. Cátedra de Ecología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Diversidad y Ecología Animal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Diversidad y Ecología Animal; ArgentinaFil: Bazzano, Gisela del Valle. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Diversidad y Ecología Animal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Diversidad y Ecología Animal; ArgentinaFil: Navarro, Joaquin Luis. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Departamento de Diversidad Biológica y Ecológica. Cátedra de Ecología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Diversidad y Ecología Animal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Diversidad y Ecología Animal; Argentin

Effect of antipredator training on spatial behaviour of male and female Greater Rheas (Rhea americana) reintroduced into the wild

The Greater Rhea (Rhea americana) is a South-American flightless bird whose populations have decreased due to poaching and fragmentation of suitable habitats, and there has been an urgent need to carry out management practices to prevent local or regional extinctions. Several studies revealed that reintroduction might be an appropriate action for increasing the viability of wild populations of this species. Nevertheless, although this is a popular and useful conservation strategy; the animals to be released should be prepared against risks like predation and dispersion that could influence the post-release success. We evaluated the effect of an antipredator training applied to captive-bred Greater Rheas before they were released into the wild, on their dispersal and home range size and overlap, supposing that the trained animals would avoid to dispersing into places with presence of predators and, consequently, they would reduce their home range. We also studied the habitat use by the released rheas. Eleven trained and nine control (untrained) animals were marked and monitored two to four times per day the first week, and from 4 to 19 consecutive days per month during four months, throughout breeding and post-breeding seasons. The locations of each animal were counted as a frequency of use of each of the five habitat types considered (crops, open areas, grassland, shrublands and salted flats) to compare these values between and within each group and sex. We estimated home range size and overlap, and the maximum linear distance travelled from the release site. The antipredator training affected the home range in different ways according to sex. Trained females exhibited smaller home ranges (mean ± S.E.: 0.54 ± 0.58 km2) than the rest of the individuals (control females 5.8 ± 0.75 km2, control and trained males: 2.11 ± 0.65 km2 and 2.96 ± 0.65 km2, respectively), whereas their overlap was greater (63.83% ± 16.95) than that of the untrained females (24.04, % ± 21.88). Males of both experimental groups showed similar distances travelled (3.21 ± 0.29 km), which were also greater than those of females (2.21 ± 0.32 km). The home ranges of males were not influenced by the training and they showed a high degree of overlapping (among control males 29.96% ± 18.95, and among trained males: 35.81% ± 18.95). Both groups similarly frequented the crops and in lesser extent open areas and grassland. Only the trained females reduced their movements and wandering as a result of the previous conditioning. They moved to crop or open areas, avoiding tall vegetation such as that present in grasslands that may difficult an earlier detection of predators. On the other hand, in the males, the influence of the reproductive season and the complex mating system exhibited by this species prevailed over the possible effects of training. Our work shows new and useful data about the spatial behaviour and reintroduction for conservation of the Greater Rhea.Fil: Vera Cortez, Marilina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Diversidad y Ecología Animal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Diversidad y Ecología Animal; ArgentinaFil: Navarro, Joaquin Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Diversidad y Ecología Animal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Diversidad y Ecología Animal; ArgentinaFil: Martella, Monica Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Diversidad y Ecología Animal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Diversidad y Ecología Animal; Argentin

Building large-scale spatially explicit models to predict the distribution of suitable habitat patches for the Greater rhea (Rhea americana), a near-threatened species

We developed large-scale spatially explicit models to predict the distribution of suitable habitat patches for the Greater rhea (Rhea americana), a near-threatened species, in two areas of central Argentina with different land use: a grassland area (ca. 4943 km2) mainly devoted to cattle grazing and an agro-ecosystem area (ca. 4006 km2) mostly used for crop production. The models were developed using logistic regression and were based on current records of Greater rhea occurrence coupled with remote sensing data, including land cover and human presence variables. The habitat suitability maps generated were used to predict the suitable habitat patch structure for wild rhea populations in each area. Fifty-one percent of the total grassland area was suitable for the species, being represented by a single large patch that included 62% of the individual locations. In the agro-ecosystem, only 28% of the total area was suitable, which was distributed among four patches. Seventy percent of rhea observations were in suitable habitat, with all rheas grouped in the largest patch. Conservation efforts for preserving wild rhea populations should be focused on maintaining habitats similar to grasslands, which are less profitable for landowners at present. Consequently, the protection of the pampas grasslands, a key habitat for this species as well as for others with similar habitat requirements, will demand strong conservation actions through the reconciliation of interests between producers and conservationists, since the proportion of croplands is increasing.Fil: Giordano, Paola Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Diversidad y Ecología Animal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Diversidad y Ecología Animal; ArgentinaFil: Navarro, Joaquin Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Diversidad y Ecología Animal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Diversidad y Ecología Animal; ArgentinaFil: Martella, Monica Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Diversidad y Ecología Animal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Diversidad y Ecología Animal; Argentin

Density and abundance of Rhea pennata garleppi (Struthioniformes: Rheidae) in the Puna ecoregion of Argentina

Background: Rhea pennata is classified internationally as a near-threatened species, with the subspecies R. p. garleppi being listed as endangered. Finding: The aim of this study was to provide updated information on the density and abundance of R. p. garleppi in the southern Puna ecoregion of Argentina. Density was estimated indirectly on the basis of monthly feces counts during 2011 and 2012, using line-transect surveys. Monthly abundance was calculated by multiplying the density of each month by the area of the reserve (400 km2 ). Population size range was calculated considering the average of the months with the highest abundance (and density) as the upper limit and the average of the months with the lowest abundance (and density) as the lower limit. The population size of this subspecies varied between 300 individuals (±60), with a density of 0.75 individuals/km2 (±0.15) during the non-breeding season, and 188 individuals (±40), with a density of 0.47 individuals/km2 (±0.10), during the reproductive season. Conclusion: This work shows the highest density record for R. p. garleppi so far and highlights changes in population size related to life history characteristics of rheas, as well as human factors that negatively affect the survival of wild populationsFil: Marinero, Nancy Veronica. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Cordoba. Instituto de Diversidad y Ecologia Animal; ArgentinaFil: Cortez, Ricardo Omar. Universidad Nacional de San Juan. Facultad de Ciencias Exactas Físicas y Naturales. Departamento de Biologia; ArgentinaFil: Navarro, Joaquin Luis. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Cordoba. Instituto de Diversidad y Ecologia Animal; ArgentinaFil: Martella, Monica Beatriz. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Cordoba. Instituto de Diversidad y Ecologia Animal; Argentin

The number of pores per area of eggshells is not always a reliable indicator of Rheidae species

Desde finales de Pleistoceno hasta el Holoceno tardío, huesos y abundantes cásca- ras de huevos atestiguan la explotación de los Rheidae de las regiones Pampeana y Chaqueña (ñandú, Rhea americana) y la Patagonia Argentina (choique, R. pennata) por parte de las pobla- ciones indígenas. El conteo de poros en una determinada área de la cáscara, esto es, la densidad, ha sido método tradicionalmente utilizado para identificar la especie. En el presente trabajo, utilizando un nuevo método que facilita el conteo, evaluamos la fiabilidad de dicho procedimien- to sobre una amplia muestra. Confirmando lo ya publicado, comprobamos que las cáscaras de ñandú tienen una densidad de poros superior a la del choique. Sin embargo, la variabilidad en la densidad de poros en ambas especies, e incluso dentro de sectores de un mismo huevo, puede dar lugar a identificaciones erróneas. Esto se produce cuando el número de poros por cm² se ubica próximo a los valores más bajos de las cáscaras de ñandú o a los más altos de las del choique. En general, parece ser más frecuente el considerar erróneamente un fragmento de cáscara de ñandú como perteneciente al choique que a la inversa. La probabilidad de cometer dicho error depende de la ubicación del fragmento en la cáscara ya que, al parecer, el método no verificó en su momento la totalidad de los rangos de densidad de poros en cada especie. Nuestros resultados muestran que la identificación de fragmentos basada en el método original no sería tan fiable como la que aquí proponemos y que su precisión, en cualquier caso, merecería ser corroborada exhaustivamente, utilizando muestras mayores y procedentes de un espectro más amplio de po- blaciones de ambas especies.From the end of the Pleistocene and up until the late Holocene, bones and abundant eggshell fragments testify to the hunting by the indigenous people of Rheidae in the Pampas and Chaco regions (greater rhea, Rhea americana), and in the Argentinian Patagonia (lesser/ Darwin's rhea, R.pennata). The traditional method to set apart eggshell fragments from these two species consisted in counting the number pores on a given area to estimate their density. In this paper we evaluate the validity of this method with a new protocol to facilitate counting and assess its reliability on a large eggshell sample. As has been repeatedly proved, the greater rhea has a larger pore density than the lesser rhea. However, the variability of this density within each species, and even within the same egg, needs to be considered as this may lead to erroneous identification. More so when the number of pores per cm2 falls in the lowest range of the greater rhea or the highest range of the lesser rhea. In general, it is easier to misidentify a greater rhea eggshell fragment for that of the lesser rhea than the other way around. The possibility of misidentification also depends on the area of the shell that is being analyzed, since the original method did not apparently assess the density of pores in different areas of the same egg for each species. Although our results indicate that identification based on the original method is not as reliable as the one we propose here, a reappraisal of it with larger samples deriving from a larger specter of populations from both species would be recommendable.Fil: Navarro, Joaquin Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Diversidad y Ecología Animal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Diversidad y Ecología Animal; ArgentinaFil: García, Karina A.. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Zoología Aplicada; ArgentinaFil: Gonzalez, Germán Alexis. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Diversidad y Ecología Animal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Diversidad y Ecología Animal; ArgentinaFil: Martella, Monica Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Diversidad y Ecología Animal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Diversidad y Ecología Animal; Argentin

Relacionando datos de paisaje a un análisis de viabilidad poblacional para evaluar la translocación como estrategia de conservación para el ñandú (Rhea americana) en el centro de Argentina

Desarrollamos un análisis de viabilidad poblacional (PVA) para ñandúes silvestres (Rhea americana) en el centro de Argentina, relacionando datos poblacionales a un modelo metapoblacional no estructurado, con el fin de evaluar la efectividad de la translocación de ñandúes como una herramienta de manejo en paisajes agrícolas. Simulamos la expansión del área cultivada por un periodo de 10 años y bajo dos escenarios de simulación, con translocación de individuos (movimiento artificial de individuos entre poblaciones) y sin translocación. Registramos: la abundancia de ñandúes, el número de poblaciones en el tiempo, el tamaño mínimo poblacional y la probabilidad de que la población caiga por debajo del umbral de 30 individuos. Comparamos los resultados con datos colectados a campo en la misma área de estudio. Al final del período de simulación, el hábitat apropiado para los ñandúes se fragmentó y redujo en un 84%. Observamos una disminución en el tamaño poblacional en ambos escenarios; sin embargo, la probabilidad de extinción fue un 85% más alta en el modelo sin translocación de individuos. Este resultado fue respaldado por la abundancia de ñandúes registrada a campo, la cual se acercó más a la predicha por el modelo con translocación, que a la correspondiente sin translocación. En consecuencia, la translocación podría ser usada como una eficiente herramienta de conservación para esta especie.We developed a population viability analysis (PVA) for wild Greater Rheas (Rhea americana) in central Argentina, linking spatial data to a non-structured metapopulation model, to evaluate the effectiveness of rhea translocations as a conservation management tool in agricultural landscapes. We simulated the expansion of the agricultural area for a 10-year period and recorded abundance, number of populations over time, expected minimum population size and the likelihood of the metapopulation to fall below the threshold of 30 individuals, under two simulation scenarios: “with translocation” (artificial movement of individuals between populations) and “without translocation.” We compared the results with field population data collected from the same study area. At the end of the simulation period, the habitat suitable for Greater Rheas was fragmented and reduced by 84%. We observed a decrease in population size in both scenarios, but the extinction probability was 85% higher in the “without translocation” model. This result was supported by the observed abundance of Rheas in the field, which was closer to values predicted in the “with translocation” than those in the “without translocation” scenarios. Therefore, translocation might be used as an efficient conservation tool for this species.Fil: Bazzano, Gisela del Valle. Universidad Nacional de Cordoba. Facultad de Cs.exactas Fisicas y Naturales. Centro de Zoologia Aplicada; ArgentinaFil: Giordano, Paola Florencia. Universidad Nacional de Cordoba. Facultad de Cs.exactas Fisicas y Naturales. Centro de Zoologia Aplicada; ArgentinaFil: Navarro, Joaquin Luis. Universidad Nacional de Cordoba. Facultad de Cs.exactas Fisicas y Naturales. Centro de Zoologia Aplicada; Argentina. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Cordoba. Instituto de Diversidad y Ecologia Animal; ArgentinaFil: Martella, Monica Beatriz. Universidad Nacional de Cordoba. Facultad de Cs.exactas Fisicas y Naturales. Centro de Zoologia Aplicada; Argentina. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Cordoba. Instituto de Diversidad y Ecologia Animal; Argentin

Effects of group size, habitat and hunting risk on vigilance and foraging behaviour in the Lesser Rhea (Rhea pennata pennata)

Gregariousness is a known anti-predator strategy, but factors other than the size of groups, such as the levels of predation pressure or habitat, can affect vigilance and foraging behaviour in birds. We studied the effects of group size, habitat (shrubland steppe v. meadows), and risk of hunting by humans (protected core area v. edge area exposed to poaching) on vigilance and foraging behaviour of wild populations of the Lesser Rhea (Rhea pennata pennata), a near-threatened ratite, in north-western Patagonia, Argentina. On average, Lesser Rheas allocated 18% of their time to vigilance and 67% to foraging. Individuals tended to be more vigilant with declining group size, in areas with low visibility that hinders escape by running, and in areas exposed to hunting, than in open habitats with abundant food or sites with low risk of hunting. Although time spent foraging was also influenced by habitat type and hunting risk, there was no direct relationship between foraging time and group size. As in other species of ratite, Lesser Rheas seem to take advantage of flocking as an anti-predation strategy. Our data do not only confirm the influence of group size, but also of habitat structure and hunting risk, in determining the behaviour of this flightless bird in the wild.Fil: Barri, Fernando Rafael. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Zoología Aplicada; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Diversidad y Ecología Animal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Diversidad y Ecología Animal; ArgentinaFil: Roldán Rueda, Héctor Nicolás. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Zoología Aplicada; ArgentinaFil: Navarro, Joaquin Luis. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Zoología Aplicada; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Diversidad y Ecología Animal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Diversidad y Ecología Animal; ArgentinaFil: Martella, Monica Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Diversidad y Ecología Animal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Diversidad y Ecología Animal; Argentina. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Zoología Aplicada; Argentin

Corticosterone stress response of Greater rhea (Rhea americana) during short-term road transport

The effect of transport stress on blood corticosterone levels in captive Greater Rheas was investigated. Twelve adult individuals (7 males; 5 females) were loaded in pairs inside wooden crates and transported along a paved road for 30 min. Blood samples were taken before the individuals were introduced into the crate (baseline value) and immediately after they were unloaded (30 min after capture). To assess whether corticosterone levels were affected by the blood sampling procedure per se, another 6 (nontransport) control birds (3 males; 3 females) were also captured and sampled at the same times as their transported counterparts. Plasma corticosterone concentrations were measured using a commercially available corticosterone 125I radio-immunoassay kit. Baseline corticosterone levels were similar in the control and transported birds (9.0 ± 1.6 and 10.4 ± 0.8 ng/mL, respectively). Transportation induced a highly significant (P < 0.001), more than 40-fold increase in the corticosterone levels (433.6 ± 35.4 ng/mL) that was about 5 times higher (P < 0.001) than in their nontransported counterparts (88.4 ± 14.8 ng/mL). The present findings suggest that Greater Rhea is a species highly sensitive to stressful manipulations. Both blood sampling and transportation induced highly significant adrenocortical responses. Considering that transportation is one of the unavoidable common practices in the management of Greater Rheas and, as shown in the present study, that it induces a significant 40-fold corticosterone stress response, efforts should focus on helping to generate management transport standards for optimization of the welfare of this ratite.Fil: Leche, Alvina. Universidad Nacional de Cordoba. Facultad de Cs.exactas Fisicas y Naturales. Centro de Zoologia Aplicada; Argentina. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Cordoba. Instituto de Diversidad y Ecologia Animal; ArgentinaFil: Della Costa, Natalia Soledad. Universidad Nacional de Cordoba. Facultad de Cs.exactas Fisicas y Naturales. Centro de Zoologia Aplicada; Argentina. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Cordoba. Instituto de Diversidad y Ecologia Animal; ArgentinaFil: Hansen, C.. Laboratorio de Análisis Clínicos Especializados; ArgentinaFil: Navarro, Joaquin Luis. Universidad Nacional de Cordoba. Facultad de Cs.exactas Fisicas y Naturales. Centro de Zoologia Aplicada; Argentina. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Cordoba. Instituto de Diversidad y Ecologia Animal; ArgentinaFil: Marin, Raul Hector. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Instituto de Investigaciones Biológicas y Tecnológicas; ArgentinaFil: Martella, Monica Beatriz. Universidad Nacional de Cordoba. Facultad de Cs.exactas Fisicas y Naturales. Centro de Zoologia Aplicada; Argentina. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Cordoba. Instituto de Diversidad y Ecologia Animal; Argentin

State of the art knowledge in adrenocortical and behavioral responses to environmental challenges in a threatened South American ratite: Implications to in situ and ex-situ conservation

The Greater Rhea (Rhea americana) is an endemic ratite to South America, whose wild populations have undergone a remarkable decrease due to habitat degradation and fragmentation by the expansion of the agricultural frontier, poaching and predation by dogs. Anthropogenic perturbations in wild environments, as well as the management in captivity, can generate different stress responses in this species, thus, the monitoring of adrenocortical and behavioral activities are considered primary assessment tools with both conservation and welfare implications. In this review we analyze and integrate the different measurements of glucocorticoids (in plasma, feces, and yolk) carried out in different captive and wild populations, taking into account the diverse predictable and unpredictable conditions to which the Greater Rhea responds in each of those environments. In addition, the translocation of this bird is presented as an application of stress physiology in field ecology for conservation purposes, in which we evaluated how this species responds when it is released into a novel environment. Our results indicate that this ratite has a striking high sensitivity of the hypothalamic-pituitaryadrenal (HPA) axis compared to that of other bird species and shows a wide variety of adrenocortical responses depending on the environment in which it lives. This suggests that its HPA axis has a phenotypic plasticity that enables the rhea to cope with the environmental challenges. In this sense, we propose that one of the routes of this plasticity could be mediated by the maternal transfer of steroid hormones to the egg. Finally, we discuss the importance of integrating the monitoring of the adrenocortical response along with the nvironmental variables that define the life history of the species, in management and conservation programs ex-situ and in situ.Fil: Navarro, Joaquin Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Diversidad y Ecología Animal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Diversidad y Ecología Animal; ArgentinaFil: Leche, Alvina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Diversidad y Ecología Animal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Diversidad y Ecología Animal; ArgentinaFil: Della Costa, Natalia Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Diversidad y Ecología Animal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Diversidad y Ecología Animal; ArgentinaFil: Vera Cortez, Marilina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Diversidad y Ecología Animal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Diversidad y Ecología Animal; ArgentinaFil: Marin, Raul Hector. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones Biológicas y Tecnológicas. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Instituto de Investigaciones Biológicas y Tecnológicas; ArgentinaFil: Martella, Monica Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Diversidad y Ecología Animal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Diversidad y Ecología Animal; Argentin