Ecology of Sceloporus gadsdeni (Squamata: Phrynosomatidae) from the central Chihuahuan Desert, Me... more Ecology of Sceloporus gadsdeni (Squamata: Phrynosomatidae) from the central Chihuahuan Desert, Mexico. Populations of Sceloporus cyanostictus Axtell and Axtell, 1971 from southwestern Coahuila have been described as a new species, Sceloporus gadsdeni Castañeda-Gaytán and Díaz-Cárdenas, 2017. Sceloporus cyanostictus is listed as Endangered by the IUCN Red List due to the decline in its habitat and its limited distribution. The subdivision of S. cyanostictus into two species further reduces the range and population size of each taxon, thereby posing a possible threat to the conservation status of each species. We describe here the sexual dimorphism, growth, age, population structure, sex ratio, density, and thermal ecology of S. gadsdeni to supplement the available information for one these two species. Males are larger than females, and when both sexes reach maturity after 1.1 yr, they have snout–vent lengths of about 60 mm. Population structures in the spring and summer are similar,...
Se determinó el ciclo reproductor de Uta stejnegeri Schmidt 1921 (antes Uta stansburiana stejnege... more Se determinó el ciclo reproductor de Uta stejnegeri Schmidt 1921 (antes Uta stansburiana stejnegeri Schmidt 1921) utilizando datos obtenidos de individuos capturados en el campo en la Reserva de Biosfera de Mapimí, Durango, México. Durante 1990 se colectaron mensualmente muestras de esta especie en dunas de arena. Los machos alcanzaron la madurez sexual a los 45.0 mm de longitud hocico-cloaca (LHC), y las hembras alcanzaron la madurez sexual a los 40.0 mm LHC. El ciclo reproductor de ambos sexos fue sincrónico. La variación significativa en peso testicular fue determinada por ANCOVA y los machos alcanzaron su máximo peso testicular entre diciembre y febrero. Los testículos comenzaron a decrecer en julio, alcanzando su peso mínimo en septiembre. Para las hembras se registró el porcentaje mensual de folículos sin vitelo, folículos con vitelo, y de huevos en oviductos. Los primeros folículos agrandados y con vitelo se observaron a la mitad de enero en las hembras. Estas mostraron una p...
In situ ecosystem-based conservation is one of the biggest challenges for the protection of biodi... more In situ ecosystem-based conservation is one of the biggest challenges for the protection of biodiversity in Mexico. Several different strategies have been established to engage landowners in maintaining ecologically important areas. The sand dune ecosystem of Coahuila´s La Laguna, is an example of an area rich in biodiversity although not yet protected from the threats of burgeoning human populations, exotic species invasions, climate change, and the loss of critical ecosystem processes that maintain the sand dune habitat quality. This area includes a rich saurian fauna where seven species of endemic lizards live in the mountains around the sand dunes and one endemic species lives within the sand dune habitat, the Coahuila fringe-toed lizard, Uma exsul, is an endangered species. In this chapter we describe the processes that maintain sand dunes dynamics, the stressors to that habitat, and the importance in adopting an ecosystem-based conservation for the protection of regional biodi...
Demise of the Lizards Despite pessimistic forecasts from recent studies examining the effects of ... more Demise of the Lizards Despite pessimistic forecasts from recent studies examining the effects of global climate change on species, and observed extinctions in local geographic areas, there is little evidence so far of global-scale extinctions. Sinervo et al. (p. 894 ; see the Perspective by Huey et al. ) find that extinctions resulting from climate change are currently reducing global lizard diversity. Climate records during the past century were synthesized with detailed surveys of Mexican species at 200 sites over the past 30 years. Temperature change has been so rapid in this region that rates of adaptation have not kept pace with climate change. The models were then extended to all families of lizards at >1000 sites across the globe, and suggest that climate change-induced extinctions are currently affecting worldwide lizard assemblages.
The previously known distribution of Acomatacarus arizonensis (Fig. 1a) covered the arid western ... more The previously known distribution of Acomatacarus arizonensis (Fig. 1a) covered the arid western and midwestern United States, where it is an ectoparasitic larvae on desert lizards, including members of Iguanidae, Crotaphytidae, Phrynosomatidae, and Teiidae (Greenberg, 1952; ...
We studied seasonal dietary patterns of Sceloporus jarrovii from a desert environment northwest o... more We studied seasonal dietary patterns of Sceloporus jarrovii from a desert environment northwest of Gomez Palacio, Durango, Mexico. Stomach contents were examined (n = 82) and relative abundance and volume were determined. Formicids (ants) were the most abundant prey ...
Page 1. SHORTER COMMUNICATIONS Journal of Herpetology, Vol. 35, No. 3, pp. 493-496, 2001 Copyrigh... more Page 1. SHORTER COMMUNICATIONS Journal of Herpetology, Vol. 35, No. 3, pp. 493-496, 2001 Copyright 2001 Society for the Study of Amphibians and Reptiles Diet of the Mexican Fringe-Toed Lizard (Uma exsul) HECTOR ...
... Gadsden, H., LE Palacios-Orona, and GA Cruz-Soto. ... Claudia Ballesteros-Barrera 1 , Enrique... more ... Gadsden, H., LE Palacios-Orona, and GA Cruz-Soto. ... Claudia Ballesteros-Barrera 1 , Enrique MartÍnez-Meyer 1 , 2 , Héctor Gadsden 3 . (2007) Effects of Land-Cover Transformation and Climate Change on the Distribution of Two Microendemic Lizards, Genus Uma, of Northern ...
Résumé: Les méthodes actuelles qui tentent d'assurer le suivi continu des conditions et des ... more Résumé: Les méthodes actuelles qui tentent d'assurer le suivi continu des conditions et des effets de la sécheresse au Mexique ne sont guère adaptées aux petites échelles géographiques. Le Service météorologique national de Mexico utilise les données ...
Résumé : Dans les trente dernières années, la pluviométrie dans l'État de Chihuahua a été tr... more Résumé : Dans les trente dernières années, la pluviométrie dans l'État de Chihuahua a été très variable. On enregistre sur tout l'État un cumul annuel moyen de 419 mm, mais depuis 1993 le cumul annuel se situe de manière continue en dessous de cette moyenne historique, ...
Ecology of Sceloporus gadsdeni (Squamata: Phrynosomatidae) from the central Chihuahuan Desert, Me... more Ecology of Sceloporus gadsdeni (Squamata: Phrynosomatidae) from the central Chihuahuan Desert, Mexico. Populations of Sceloporus cyanostictus Axtell and Axtell, 1971 from southwestern Coahuila have been described as a new species, Sceloporus gadsdeni Castañeda-Gaytán and Díaz-Cárdenas, 2017. Sceloporus cyanostictus is listed as Endangered by the IUCN Red List due to the decline in its habitat and its limited distribution. The subdivision of S. cyanostictus into two species further reduces the range and population size of each taxon, thereby posing a possible threat to the conservation status of each species. We describe here the sexual dimorphism, growth, age, population structure, sex ratio, density, and thermal ecology of S. gadsdeni to supplement the available information for one these two species. Males are larger than females, and when both sexes reach maturity after 1.1 yr, they have snout–vent lengths of about 60 mm. Population structures in the spring and summer are similar,...
Se determinó el ciclo reproductor de Uta stejnegeri Schmidt 1921 (antes Uta stansburiana stejnege... more Se determinó el ciclo reproductor de Uta stejnegeri Schmidt 1921 (antes Uta stansburiana stejnegeri Schmidt 1921) utilizando datos obtenidos de individuos capturados en el campo en la Reserva de Biosfera de Mapimí, Durango, México. Durante 1990 se colectaron mensualmente muestras de esta especie en dunas de arena. Los machos alcanzaron la madurez sexual a los 45.0 mm de longitud hocico-cloaca (LHC), y las hembras alcanzaron la madurez sexual a los 40.0 mm LHC. El ciclo reproductor de ambos sexos fue sincrónico. La variación significativa en peso testicular fue determinada por ANCOVA y los machos alcanzaron su máximo peso testicular entre diciembre y febrero. Los testículos comenzaron a decrecer en julio, alcanzando su peso mínimo en septiembre. Para las hembras se registró el porcentaje mensual de folículos sin vitelo, folículos con vitelo, y de huevos en oviductos. Los primeros folículos agrandados y con vitelo se observaron a la mitad de enero en las hembras. Estas mostraron una p...
In situ ecosystem-based conservation is one of the biggest challenges for the protection of biodi... more In situ ecosystem-based conservation is one of the biggest challenges for the protection of biodiversity in Mexico. Several different strategies have been established to engage landowners in maintaining ecologically important areas. The sand dune ecosystem of Coahuila´s La Laguna, is an example of an area rich in biodiversity although not yet protected from the threats of burgeoning human populations, exotic species invasions, climate change, and the loss of critical ecosystem processes that maintain the sand dune habitat quality. This area includes a rich saurian fauna where seven species of endemic lizards live in the mountains around the sand dunes and one endemic species lives within the sand dune habitat, the Coahuila fringe-toed lizard, Uma exsul, is an endangered species. In this chapter we describe the processes that maintain sand dunes dynamics, the stressors to that habitat, and the importance in adopting an ecosystem-based conservation for the protection of regional biodi...
Demise of the Lizards Despite pessimistic forecasts from recent studies examining the effects of ... more Demise of the Lizards Despite pessimistic forecasts from recent studies examining the effects of global climate change on species, and observed extinctions in local geographic areas, there is little evidence so far of global-scale extinctions. Sinervo et al. (p. 894 ; see the Perspective by Huey et al. ) find that extinctions resulting from climate change are currently reducing global lizard diversity. Climate records during the past century were synthesized with detailed surveys of Mexican species at 200 sites over the past 30 years. Temperature change has been so rapid in this region that rates of adaptation have not kept pace with climate change. The models were then extended to all families of lizards at >1000 sites across the globe, and suggest that climate change-induced extinctions are currently affecting worldwide lizard assemblages.
The previously known distribution of Acomatacarus arizonensis (Fig. 1a) covered the arid western ... more The previously known distribution of Acomatacarus arizonensis (Fig. 1a) covered the arid western and midwestern United States, where it is an ectoparasitic larvae on desert lizards, including members of Iguanidae, Crotaphytidae, Phrynosomatidae, and Teiidae (Greenberg, 1952; ...
We studied seasonal dietary patterns of Sceloporus jarrovii from a desert environment northwest o... more We studied seasonal dietary patterns of Sceloporus jarrovii from a desert environment northwest of Gomez Palacio, Durango, Mexico. Stomach contents were examined (n = 82) and relative abundance and volume were determined. Formicids (ants) were the most abundant prey ...
Page 1. SHORTER COMMUNICATIONS Journal of Herpetology, Vol. 35, No. 3, pp. 493-496, 2001 Copyrigh... more Page 1. SHORTER COMMUNICATIONS Journal of Herpetology, Vol. 35, No. 3, pp. 493-496, 2001 Copyright 2001 Society for the Study of Amphibians and Reptiles Diet of the Mexican Fringe-Toed Lizard (Uma exsul) HECTOR ...
... Gadsden, H., LE Palacios-Orona, and GA Cruz-Soto. ... Claudia Ballesteros-Barrera 1 , Enrique... more ... Gadsden, H., LE Palacios-Orona, and GA Cruz-Soto. ... Claudia Ballesteros-Barrera 1 , Enrique MartÍnez-Meyer 1 , 2 , Héctor Gadsden 3 . (2007) Effects of Land-Cover Transformation and Climate Change on the Distribution of Two Microendemic Lizards, Genus Uma, of Northern ...
Résumé: Les méthodes actuelles qui tentent d'assurer le suivi continu des conditions et des ... more Résumé: Les méthodes actuelles qui tentent d'assurer le suivi continu des conditions et des effets de la sécheresse au Mexique ne sont guère adaptées aux petites échelles géographiques. Le Service météorologique national de Mexico utilise les données ...
Résumé : Dans les trente dernières années, la pluviométrie dans l'État de Chihuahua a été tr... more Résumé : Dans les trente dernières années, la pluviométrie dans l'État de Chihuahua a été très variable. On enregistre sur tout l'État un cumul annuel moyen de 419 mm, mais depuis 1993 le cumul annuel se situe de manière continue en dessous de cette moyenne historique, ...
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