Papers by Miguel Angel Martínez Morales
Acta Oecologica-international Journal of Ecology, 2010
In natural ecosystems, species assemblages among isolated ecological communities such as continen... more In natural ecosystems, species assemblages among isolated ecological communities such as continental islands often show a nested pattern in which biotas of sites with low species richness are non-random subsets of biotas of richer sites. The distribution of centipede (Chilopoda) species in the central and south Aegean archipelago was tested for nestedness. To achieve this aim we used distribution data for 53 species collected on 24 continental Aegean islands (Kyklades and Dodekanisa). Based on the first-order jackknife estimator, most of islands were comprehensively surveyed. In order to quantify nestedness, we used the nestedness temperature calculator (NTC) as well as the nestedness metric based on overlap and decreasing Fill (NODF). NTC indicated that data exhibited a high degree of nestedness in the central and south Aegean island complexes. As far as the Kyklades and Dodekanisa are concerned, NTC showed less nested centipede structures than the 24 islands. Likewise, NODF revealed a significant degree of nestedness in central and south Aegean islands. It also showed that biotas matrices without singletons were more nested than the complete ones (Aegean, Kyklades and Dodekanisa). The two commonest centipede taxa (lithobiomorphs and geophilomorphs) contributed differently to centipede assemblages. In the Kyklades and Dodekanisa, geophilomorphs did not show a reliable nested arrangement unlike lithobiomorphs. In relation to the entire data set, nestedness was positively associated with the degree of isolation. In the Kyklades altitudinal range best explained nestedness patterns, while in Dodekanisa habitat heterogeneity proved to be more important for the centipede communities. Island area does not seem to be a significant explanatory variable. Some of our results from the Kyklades were critically compared with those for terrestrial isopod and land snail nested assemblages from the same geographical area. The complex geological and palaeogeographical history of the Aegean archipelago partly accounted for the pattern of centipede assemblages.
Acta Oecologica-international Journal of Ecology, 2010
In natural ecosystems, species assemblages among isolated ecological communities such as continen... more In natural ecosystems, species assemblages among isolated ecological communities such as continental islands often show a nested pattern in which biotas of sites with low species richness are non-random subsets of biotas of richer sites. The distribution of centipede (Chilopoda) species in the central and south Aegean archipelago was tested for nestedness. To achieve this aim we used distribution data for 53 species collected on 24 continental Aegean islands (Kyklades and Dodekanisa). Based on the first-order jackknife estimator, most of islands were comprehensively surveyed. In order to quantify nestedness, we used the nestedness temperature calculator (NTC) as well as the nestedness metric based on overlap and decreasing Fill (NODF). NTC indicated that data exhibited a high degree of nestedness in the central and south Aegean island complexes. As far as the Kyklades and Dodekanisa are concerned, NTC showed less nested centipede structures than the 24 islands. Likewise, NODF revealed a significant degree of nestedness in central and south Aegean islands. It also showed that biotas matrices without singletons were more nested than the complete ones (Aegean, Kyklades and Dodekanisa). The two commonest centipede taxa (lithobiomorphs and geophilomorphs) contributed differently to centipede assemblages. In the Kyklades and Dodekanisa, geophilomorphs did not show a reliable nested arrangement unlike lithobiomorphs. In relation to the entire data set, nestedness was positively associated with the degree of isolation. In the Kyklades altitudinal range best explained nestedness patterns, while in Dodekanisa habitat heterogeneity proved to be more important for the centipede communities. Island area does not seem to be a significant explanatory variable. Some of our results from the Kyklades were critically compared with those for terrestrial isopod and land snail nested assemblages from the same geographical area. The complex geological and palaeogeographical history of the Aegean archipelago partly accounted for the pattern of centipede assemblages.
I assessed the population status and habitat preferences of the Cozumel Cu- rassow, Crax rubra gr... more I assessed the population status and habitat preferences of the Cozumel Cu- rassow, Crax rubra griscomi, in the forests of Cozumel Island, Mexico, from October 1994 to June 1995. The estimated density was 0.9 curassows km-* with a population size of about 300 birds. These numbers and the fact that the Cozumel Curassow is restricted to the island, place this
Oikos, 2005
In an ecological community, groups of species may or may not have a nested structure. Furthermore... more In an ecological community, groups of species may or may not have a nested structure. Furthermore, any nested structure detected could have several causes, each of which would have to be identified, since they may have important theoretical and management implications. In this paper, I assessed the nested structure of bird communities using cloud forest fragments in eastern Mexico to identify bird species and groups of species sensitive to cloud forest fragmentation. Sensitive species were expected to have a nested arrangement highly correlated with forest fragmentation intensity. Analysis identified the following groups of birds as showing a nested structure highly correlated with cloud forest fragmentation: birds with a body mass between 100 and 300 g and larger than 600 g, some trophic behavioural guilds (terrestrial granivore, terrestrial granivore–frugivore, understory granivore–frugivore, arboreal granivore–frugivore, gleaning terrestrial insectivore, gleaning understory insectivore, cliff gleaning insectivore, nocturnal aerial insectivore, diurnal raptor, nocturnal raptor, terrestrial omnivore, scavenger), forest interior and generalist birds, species restricted to cloud forest, and threatened species. This study shows that the analysis of the nested species assemblage can be considered a useful tool to identify species sensitivity to ecological or landscape patterns and processes, in this case, species or groups of species affected by a fragmented landscape pattern.
Resumen. Este trabajo presenta los resultados de un inventario avifaunístico realizado de 1997 a ... more Resumen. Este trabajo presenta los resultados de un inventario avifaunístico realizado de 1997 a 1999 en fragmentos de bosque mesófi lo de montaña del noreste de Hidalgo, México. Se registraron 41 familias y 181 especies de aves mediante observaciones visuales y auditivas en 2 057 puntos de conteo, lo que representó el 98% de las especies esperadas en el área de estudio, para el período y método de muestreo utilizado. Se detectaron 16 especies restringidas al bosque mesófi lo, 11 endémicas de México y 3 de distribución restringida. Adicionalmente, con base en la legislación mexicana vigente, 28 de las especies registradas están incluidas dentro de alguna categoría de riesgo de conservación. Esta comunidad de aves estuvo dominada por especies de aves pequeñas, raras (poco abundantes) y residentes. Es probable que las más vulnerables de sufrir extinciones locales sean las especies raras y restringidas al bosque mesófi lo, donde están incluidas las 3 especies de distribución restringida (Dendrortyx barbatus, Glaucidium sanchezi y Cyanolyca nana). La avifauna del bosque mesófi lo de esta región incluye al 40% de la avifauna estatal, lo que destaca la relevancia de este tipo de vegetación y una urgente necesidad de establecer estrategias de manejo para su conservación.
Diversity and Distributions, 2010
Aim The Rufous-backed Robin Turdus rufopalliatus is a bird endemic to the Pacific slope of Mexic... more Aim The Rufous-backed Robin Turdus rufopalliatus is a bird endemic to the Pacific slope of Mexico. The species recently established populations in several localities in the Mexican Central Highlands. Based on available data, we modelled the range expansion of the Rufous-backed Robin in Mexico to understand the pattern, mechanisms and ecological and biogeographic implications of its expansion.Location Mexico.Methods We assessed the species’ presence and habitat requirements at two spatial scales. At the site level, we evaluated the relationship between land use and species presence in an urban environment. At the country level, we generated a niche model. We then produced a dispersion model through the interpolation of points generated from information derived from the niche model, the location of records within and outside its native distribution range, the species’ natural history, habitat requirements and its estimated dispersion rate (4.2 km year−1).Results The dispersion model predicted that the species will significantly increase its distribution range in Mexico in the coming decades. Its expansion would occur by a stepping-stone colonization of suitable habitat in areas of native vegetation and human settlements. The model predicted that the species should arrive on the Gulf slope of Mexico before 2025.Main conclusions Mechanisms that could explain the species’ success in establishing viable populations outside its native distribution include its dispersion ability, competitive release, the urban heat island phenomenon and the trade of wild birds. The geographic range expansion of the Rufous-backed Robin will probably create new interactions with other species, particularly with close taxonomic and ecological relatives. The increase in the distribution range of the Rufous-backed Robin has resulted from direct and indirect human-induced dispersion; therefore, it cannot be considered a fading endemism. In part of its expanded range (to date the Mexican Central Highlands), it should be considered an invasive alien species.
We provide evidence of the presence of 18 additional bird species to the avifauna of the state of... more We provide evidence of the presence of 18 additional bird species to the avifauna of the state of Hidalgo (including an alien species). We also provide information of 14 outstanding or recent records of species previously recorded in the state. To date, the confirmed presence of 496 native bird species constitutes the species richness of Hidalgo, in addition to 6 introduced alien species.
Resumen. Se realizó un análisis sistemático de la distribución de las especies del género Crotalu... more Resumen. Se realizó un análisis sistemático de la distribución de las especies del género Crotalus en México para conocer los sitios de mayor concentración y evaluar su nivel de representatividad dentro del esquema federal de áreas naturales protegidas (ANP). A partir de registros georreferenciados se construyeron los modelos de distribución potencial de las especies con un número suficiente de registros, empleando los algoritmos GARP y MaxEnt. Con estos mapas de distribución se dedujeron las áreas de mayor concentración de especies y se estimó su presencia en las ANP. La mayor riqueza de especies se concentra en las regiones de la sierra Madre Occidental, el noroeste del Altiplano Mexicano, la porción norte de la sierra Madre Oriental y el extremo oeste de la Faja Volcánica Transmexicana. Se estima que el 84.4% de las ANP incluyen al menos 1 especie de Crotalus y que el 88.2% de las especies que se distribuyen en México están presentes al menos dentro de 1 ANP. En este contexto de alta representatividad, el plantear la incorporación de ANP adicionales para la protección y conservación de crotalinos se dificulta, por lo que debe optarse por estrategias alternativas, tales como educación ambiental, conservación de hábitats mediante el uso sustentable de recursos, y el manejo y reproducción en cautiverio de especies en riesgo; además, se debe fomentar la investigación y el monitoreo de poblaciones.
In natural ecosystems, species assemblages among isolated ecological communities such as continen... more In natural ecosystems, species assemblages among isolated ecological communities such as continental islands often show a nested pattern in which biotas of sites with low species richness are non-random subsets of biotas of richer sites. The distribution of centipede (Chilopoda) species in the central and south Aegean archipelago was tested for nestedness. To achieve this aim we used distribution data for 53 species collected on 24 continental Aegean islands (Kyklades and Dodekanisa). Based on the first-order jackknife estimator, most of islands were comprehensively surveyed. In order to quantify nestedness, we used the nestedness temperature calculator (NTC) as well as the nestedness metric based on overlap and decreasing Fill (NODF). NTC indicated that data exhibited a high degree of nestedness in the central and south Aegean island complexes. As far as the Kyklades and Dodekanisa are concerned, NTC showed less nested centipede structures than the 24 islands. Likewise, NODF revealed a significant degree of nestedness in central and south Aegean islands. It also showed that biotas matrices without singletons were more nested than the complete ones (Aegean, Kyklades and Dodekanisa). The two commonest centipede taxa (lithobiomorphs and geophilomorphs) contributed differently to centipede assemblages. In the Kyklades and Dodekanisa, geophilomorphs did not show a reliable nested arrangement unlike lithobiomorphs. In relation to the entire data set, nestedness was positively associated with the degree of isolation. In the Kyklades altitudinal range best explained nestedness patterns, while in Dodekanisa habitat heterogeneity proved to be more important for the centipede communities. Island area does not seem to be a significant explanatory variable. Some of our results from the Kyklades were critically compared with those for terrestrial isopod and land snail nested assemblages from the same geographical area. The complex geological and palaeogeographical history of the Aegean archipelago partly accounted for the pattern of centipede assemblages.
We assessed the current conservation status and population trends of Cozumel Curassows (Crax rubr... more We assessed the current conservation status and population trends of Cozumel Curassows (Crax rubra griscomi), a critically endangered and endemic cracid of Cozumel Island, Mexico. Distance sampling was used to estimate the population size in 2005 and compare it with a previous estimate in 1995. Population viability analysis (PVA) was used to model population trends, considering ecological and environmental conditions prevailing in 1995 and 2005. Additional PVA models were constructed using different hypothetical scenarios to assess the effects of particular factors and management strategies on population trends. We estimated a population size of 372 ± 155 curassows in the island's tropical semideciduous forest, before two hurricanes hit Cozumel Island in 2005. PVA modeling predicted a steep decline in population size in the ensuing decades as a result of an increased frequency and intensity of hurricanes related to global climate change, and an observed female bias in the sex ratio likely caused by a higher mortality rate for adult males. We recommend urgent management actions for the long-term conservation of Cozumel Curassows, including a ban on hunting, eradication of the feral fauna, particularly dogs, and implementation of a captive-breeding program to supplement the wild population.
Cozumel Island, Mexico, harbours two endemic species of dwarf procyonids: the Pygmy Raccoon Procy... more Cozumel Island, Mexico, harbours two endemic species of dwarf procyonids: the Pygmy Raccoon Procyon pygmaeus and the Dwarf Coati Nasua nelsoni. Both species are Critically Endangered, and are among the world's most threatened Carnivora. Here we summarise the research we have been conducting on their ecology, evolution, genetics, and conservation. We also summarise the conservation initiatives we have been undertaking and promoting in order to advance the conservation of these unique species and their habitats. This effort illustrates the importance of an interdisciplinary approach in conservation science and action in maximising effectiveness. Nevertheless, the precarious status of the species make it imperative to continue and expand the work we have carried out in Cozumel to prevent two imminent global extinctions.
Resumen. Este trabajo presenta los resultados de un inventario avifaunístico realizado de 1997 a ... more Resumen. Este trabajo presenta los resultados de un inventario avifaunístico realizado de 1997 a 1999 en fragmentos de bosque mesófi lo de montaña del noreste de Hidalgo, México. Se registraron 41 familias y 181 especies de aves mediante observaciones visuales y auditivas en 2 057 puntos de conteo, lo que representó el 98% de las especies esperadas en el área de estudio, para el período y método de muestreo utilizado. Se detectaron 16 especies restringidas al bosque mesófi lo, 11 endémicas de México y 3 de distribución restringida. Adicionalmente, con base en la legislación mexicana vigente, 28 de las especies registradas están incluidas dentro de alguna categoría de riesgo de conservación. Esta comunidad de aves estuvo dominada por especies de aves pequeñas, raras (poco abundantes) y residentes. Es probable que las más vulnerables de sufrir extinciones locales sean las especies raras y restringidas al bosque mesófi lo, donde están incluidas las 3 especies de distribución restringida (Dendrortyx barbatus, Glaucidium sanchezi y Cyanolyca nana). La avifauna del bosque mesófi lo de esta región incluye al 40% de la avifauna estatal, lo que destaca la relevancia de este tipo de vegetación y una urgente necesidad de establecer estrategias de manejo para su conservación.
The cloud forest is one of the rarest and most threatened ecosystems in Mexico, although it contr... more The cloud forest is one of the rarest and most threatened ecosystems in Mexico, although it contributes highly to the country's biological diversity and provides important ecological services. It is a naturally fragmented ecosystem, but anthropogenic deforestation and fragmentation has been severe. Consequently, it is essential to identify landscape patterns critical for the conservation of cloud forest. In order to understand how landscape patterns affect diversity in this ecosystem, this study explores the consequences of cloud forest fragmentation on bird diversity in eastern Mexico. I analysed the response of bird species richness and abundance as a function of forest fragment size, shape, topographical complexity, altitudinal range, connectivity, and proportion of landscape forested area in a system of 13 cloud forest fragments. Fragment shape was the main characteristic positively related to species richness in the bird community, but a differential response to landscape patterns was also detected. Fragment size was the main characteristic influencing the segment of the bird community depending mostly on forest, that is to say, forest interior and generalist species. In contrast, the extent of forest edge, expressed as fragment shape, produced a positive response of forest border species. Both, forest dependent and border dependent species positively responded to the extent of their suitable habitat. The immediate and most effective ecologically oriented conservation strategy for the region is the conservation of the largest cloud forest fragments.
Cozumel Island in the Mexican Caribbean is inhabited by four carnivores, of which two, the Cozume... more Cozumel Island in the Mexican Caribbean is inhabited by four carnivores, of which two, the Cozumel coati Nasua nelsoni and pygmy raccoon Procyon pygmaeus, are endemic species. The taxonomic status of a third carnivore, a dwarf gray fox Urocyon cinereoargenteus, is undetermined, but may deserve subspecific or species-level recognition. The fourth species, the kinkajou (Potos flavus), may be a recent introduction. We review the status of these carnivores, report our field observations and results of line transect and trapping efforts, discuss current threats to these taxa, and make recommendations for 2 their conservation. A population density of 0.43 6 0.27 coatis / km , and a total island population size of 150 6 95 individuals, was estimated from 386 km of line transects in 1994-1995. Intensive trapping efforts (1479 trap-nights) in 2001 at multiple localities were unsuccessful. Pygmy raccoons were observed in the mangrove and coastal wetland areas of the island and in 2001 we captured 11 individuals with the same sampling efforts as for coatis (8.8 raccoons / 1000 trap-nights). The gray fox is also apparently very rare on the island. While a few observations of the animals have been made (1984, 1994 and 2001), no animals were seen along transects and none were trapped. The primary threats to the persistence of these taxa include introduced congeners, introduced predators, parasite and disease spill-over from exotic animals, habitat fragmentation, hunting and collection as pets, and hurricanes. We suggest that the Cozumel coati, pygmy raccoon, and the Cozumel population of the gray fox be considered as Critically Endangered according to the IUCN classification system. Current conservation actions focusing on Cozumel carnivores are extremely limited. We recommend eradication of introduced species, maintenance of habitat connectivity, ex situ conservation programs, explicit public policies on land-use and sustainable development, public awareness campaigns, and continuous scientific research and monitoring.
Se reportan nuevos registros y ampliaciones en el área de distribución de Harpagus bidentatus, Gl... more Se reportan nuevos registros y ampliaciones en el área de distribución de Harpagus bidentatus, Glaucidium sanchezi, Attila spadiceus, Cyanolyca nana, Oreoscoptes montanus y Peucedramus taeniatus. Estas seis especies de aves fueron registradas en el bosque mesófilo de montaña del estado de Hidalgo, México. Dos de estas especies (G. sanchezi y C. nana) son especies de distribución restringida, lo que eleva a tres el número de especies de distribución restringida en la zona.
We present evidence indicating that the boa (Boa constrictor) was introduced onto Cozumel Island,... more We present evidence indicating that the boa (Boa constrictor) was introduced onto Cozumel Island, Quintana Roo, Mexico, in 1971. This snake is now firmly established and has a wide distribution on Cozumel. We recorded an encounter rate of 1.8 boas per 100 km of forest surveyed. The introduction of the boa onto Cozumel, where it has few predators, is a threat to the existence of endemic and other native terrestrial vertebrates of the island. We recommend the following immediate actions: (1) undertake research to confirm the origin of the boa on Cozumel; (2) assess the effect of the boa on the biota of Cozumel; and, (3) if an anthropogenic origin is confirmed, an eradication programme for the boa on Cozumel should be undertaken, obtaining information on the biology and ecology of the species. Options for the destiny of the eradicated boas are discussed.
Uploads
Papers by Miguel Angel Martínez Morales