Ecological niche models provide useful predictions of species distributions, but may fail to detect reductions in distribution due to factors other than habitat loss, such as hunting or trade. From 2001 to 2009, we conducted field-surveys along the Mexican Pacific coast to obtain presence-absence data for nine Psittacidae species. We applied Genetic Algorithm for Rule set Prediction (GARP) ecological niche modeling, using field-survey presence data to determine the potential current distribution of each species, and incorporated absence data to delineate extirpation areas. All parrot species showed a reduced current distribution, ranging from 9.6 to 79% reduction of estimated original distribution. The threatened and endemic species of Amazona oratrix, Amazona finschi, and Forpus cyanopygius suffered the greatest distribution reduction, higher than previously estimated by habitat-based models, suggesting that capture for trade may have caused extirpation of these species. The greatest extent of current distribution was occupied by Aratinga canicularis, Amazona albifrons and Ara militaris, which continue to occur throughout most of their original distribution. Amazona auropalliata, Aratinga strenua, and Brotogeris jugularis also occur throughout their restricted distribution in coastal Chiapas, and show a relatively small distribution reduction, but had the highest proportion of modified lands within their current distributions. Our results highlighted the regions of coastal Guerrero, northern Nayarit, and southern Sinaloa where parrot species have been extirpated even though GARP models predicted suitable habitat available. Ideally distribution models should be verified in the field to determine conservation priorities, and efforts should be directed to maintain populations of species with greatest distribution reductions.

5Autor para la correspondencia: csaenzromero@gmail.com.Resumen: El modelado del hábitat climático propicio para la distribución potencial de especies es una herramienta poderosa para proyectar los impactos del cambio climático y sugerir medidas de manejo que permitan aminorar sus efectos negativos. Los objetivos del presente trabajo fueron: (1) determinar la distribución potencial del hábitat climático propicio para Swietenia macrophylla primariamente para la Península de Yucatán, México y para Guatemala, Belice y este de Honduras y (2) sugerir medidas de manejo para reacoplar las poblaciones contemporáneas al clima que les será propicio en la década centrada en el año 2030. Se obtuvieron registros geográficos para S. macrophylla del Inventario Nacional Forestal y Suelos y grids climáticas para clima contemporáneo (promedio 1961-1990), y futuro (década centrada en 2030), con escenarios de concentraciones intermedias (6.0 W/m 2 ) de gases de efecto invernadero. Se modeló la distribución potencial bajo el clima contemporáneo y futuro usando MaxEnt. Para el año 2030 se proyecta una pérdida de hábitat climático del 60 % en relación al contemporáneo para la Península de Yucatán, Guatemala, Belice y este de Honduras. El hábitat climático propicio prácticamente desaparece en Quintana Roo, desplazándose hacia la Reserva de la Biosfera de Calakmul. Se propone recolectar semilla en la distribución actual en Quintana Roo y plantar en esa Reserva, con el propósito de realizar conservación ex-situ, reacoplando las poblaciones al clima futuro que les es propicio. Palabras clave: Cambio climático, clima contemporáneo, hábitat climático, MaxEnt, Península de Yucatán. Abstract:The suitable climate habitat modeling for the potential distribution of species is a powerful tool to project the impacts of climate change and to suggest management measures that may mitigate its negative effects. The objectives of this study were: (1) To determine the potential distribution of Swietenia macrophylla primarily for the Yucatan Peninsula, México and for Guatemala, Belize and eastern Honduras, and (2) to suggest management actions for recoupling the contemporary populations to their suitable climate habitat by the decade centered in the year 2030. Geographical records for S. macrophylla were obtained from the Mexican National Forest and Soil Inventory and the grids for contemporary (average 1961-1990) and future (decade centered on 2030), with intermediate greenhouse-effect gas concentration scenarios (6.0 W/m 2 ). Potential distribution under the contemporary and future climate was modeled using MaxEnt. For the decade of 2030 it is projected a climatic habitat loss of 60 % in relation to contemporary distribution at the Yucatan Peninsula, Guatemala, Belize, and eastern Honduras. Suitable climate habitat practically disappears in Quintana Roo, moving to the Calakmul Biosphere Reserve. It is proposed to collect seed in the current distribution in Quintana Roo and planting inside the Reserve, with the purpose of conducting ex situ conservation...

Abstract:Our objectives were to predict and map the climatic niche for Pinus leiophylla for a period of normalization (years 1961-1990) and future (2030, 2060 and 2090) climates, and to suggest management strategies to accommodate climate changes, and discuss implications for conservation. A bioclimate model predicting the presence or absence of P. leiophylla (lumped with its putative variety P. leiophylla var. chihuahuana ) was developed by using the Random Forests classifi cation tree on Mexican and Unites States of America forest inventory data. The bioclimatic model had an average error of prediction of 4.6 %. The model used six predictor variables, dominated by precipitation variables. Projecting the 1961-1990 climate niche into future climates provided by three general circulation models and two greenhouse-effect gas emission scenarios, suggested that the area occupied by the niche should diminish rapidly over the course of the century: a decrease of 35 % by the decade surrounding 2030, 50 % for 2060, and 76 % for 2090. The most serious habitat reduction occurs at both latitudinal extremes of the species distribution: Chiricagua Mountains, Arizona, Unites States of America in the northern extreme, and at Oaxaca State, Mexico, in the southernmost extreme. There is no indication at all of expansion of suitable climatic habitat northwards. We urge establishing seed banks encompassing seed from provenances sampled from the largest part possible of the natural distribution, and start assisted migration tests, to realign the natural populations with the climate for which they are adapted and that will occur at higher altitudes. Keywords: assisted migration, climate change impacts, Random Forests classifi cation tree, responses to climate.Resumen: Nuestros objetivos fueron predecir y mapear el nicho climático para Pinus leiophylla, para los climas del período 1961-1990 y del futuro (2030, 2060 y 2090), sugerir estrategias de manejo para adaptarse al cambio climático y discutir implicaciones para su conservación. Se desarrolló un modelo bioclimático que predice la presencia o ausencia de P. leiophylla (agrupado con su supuesta variedad P. leiophylla var. chihuahuana) utilizando la técnica de árboles de clasifi cación Random Forests, con datos del inventario forestal de México y Estados Unidos. El modelo bioclimático tuvo un error promedio de predicción de 4.6 %. El modelo utilizó seis variables de predicción, dominadas por variables de precipitación. La proyección del nicho climático 1961-1990 en climas futuros, a partir de tres modelos de circulación general y dos escenarios de emisiones de gases de efecto invernadero, sugieren que el área ocupada por el nicho disminuirá rápidamente durante el siglo: una disminución del 35 % en la década alrededor del 2030, del 50 % para 2060, y 76 % para 2090. La reducción más grave de hábitat se produce en los dos extremos latitudinales de la distribución de las especies: Montañas Chiricagua, Arizona, en Estados Unidos en el extremo norte y en el estado de Oaxaca, México, en...

The Endangered yellow-headed parrot Amazona oratrix along the Pacific coast of Mexico T i b e r i o C e s a r M o n t e r r u b i o -R i c o , K a t h e r i n e R e n t o n , J u a n M a n u e l O R T E G A -R O D R Í G U E Z , A l e j a n d r o P É r e z -A r t e a g a and R A M Ó N C a n c i n o -M u r i l l o Abstract The yellow-headed parrot Amazona oratrix is categorized as Endangered on the IUCN Red List but little is known about its distribution, particularly along the Pacific coast of Mexico. We used ecological niche models, with presence records from museum collections and historical sightings, overlain on vegetation maps, to predict the historical range of the yellow-headed parrot along the Pacific coast of Mexico. We compared this with the current range of the species, estimated with ecological niche models using presence-absence data from surveys during 2003-2008. We estimate that the range of the yellow-headed parrot along Mexico's Pacific coast has contracted by 79%. The current range may now cover only 18,957 km 2 , in three main areas. At one of these, a small isolated area on the coast of Jalisco, the species may be vulnerable to extirpation or genetic endogamy. There is a lack of conserved tropical semi-deciduous forest, which provides optimal habitat for reproduction of this parrot, within the current range of the species. Only the south, along the coast of Oaxaca, has extensive areas of this habitat. There are only three, small, protected areas within the species' current range. Conservation strategies need to be implemented to restore connectivity between the three main areas of the current range of the yellow-headed parrot on the Pacific coast of Mexico.

The high biodiversity of the Mexican montane forests is concentrated on the Trans‐Mexican Volcanic Belt, where several Protected Natural Areas exist. Our study examines the projected changes in suitable climatic habitat for five conifer species that dominate these forests. The species are distributed sequentially in overlapping altitudinal bands: Pinus hartwegii at the upper timberline, followed by Abies religiosa, the overwintering host of the Monarch butterfly at the Monarch Butterfly Biosphere Reserve, P. pseudostrobus, the most important in economic terms, and P. devoniana and P. oocarpa, which are important for resin production and occupy low altitudes where montane conifers merge with tropical dry forests. We fit a bioclimatic model to presence–absence observations for each species using the Random Forests classification tree with ground plot data. The models are driven by normal climatic variables from 1961 to 1990, which represents the reference period for climate‐induced vegetation changes. Climate data from an ensemble of 17 general circulation models were run through the classification tree to project current distributions under climates described by the RCP 6.0 watts/m2 scenario for the decades centered on years 2030, 2060 and 2090. The results suggest that, by 2060, the climate niche of each species will occur at elevations that are between 300 to 500 m higher than at present. By 2060, habitat loss could amount to 46–77%, mostly affecting the lower limits of distribution. The two species at the highest elevation, P. hartwegii and A. religiosa, would suffer the greatest losses while, at the lower elevations, P. oocarpa would gain the most niche space. Our results suggest that conifers will require human assistance to migrate altitudinally upward in order to recouple populations with the climates to which they are adapted. Traditional in situ conservation measures are likely to be equivalent to inaction and will therefore be incapable of maintaining current forest compositions.