The PREDICTS project—Projecting Responses of Ecological Diversity In Changing Terrestrial Systems... more The PREDICTS project—Projecting Responses of Ecological Diversity In Changing Terrestrial Systems (www.predicts.org.uk)—has collated from published studies a large, reasonably representative database of comparable samples of biodiversity from multiple sites that differ in the nature or intensity of human impacts relating to land use. We have used this evidence base to develop global and regional statistical models of how local biodiversity responds to these measures. We describe and make freely available this 2016 release of the database, containing more than 3.2 million records sampled at over 26,000 locations and representing over 47,000 species. We outline how the database can help in answering a range of questions in ecology and conservation biology. To our knowledge, this is the largest and most geographically and taxonomically representative database of spatial comparisons of biodiversity that has been collated to date; it will be useful to researchers and international efforts wishing to model and understand the global status of biodiversity.
he PREDICTS project—Projec ng Responses of Ecological Diversity In Changing Terrestrial Systems (... more he PREDICTS project—Projec ng Responses of Ecological Diversity In Changing Terrestrial Systems (www.predicts.org.uk)—has collated from published studies a large, reasonably representa ve database of comparable samples of biodiversity from mul ple sites that di er in the nature or intensity of human impacts rela ng to land use. We have used this evidence base to develop global and regional sta s cal models of how local biodiversity responds to these measures. We describe and make freely available this 2016 release of the database, containing more than 3.2 million records sampled at over 26,000 loca ons and represen ng over 47,000 species. We outline how the database can help in answering a range of ques ons in ecology and conserva on biology. To our knowledge, this is the largest and most geographically and taxonomically representa ve database of spa al comparisons of biodiversity that has been collated to date; it will be useful to researchers and interna onal e orts wishing to model and understand the global status of biodiversity.
The PREDICTS project—Projecting Responses of Ecological Diversity In Changing Terrestrial Systems... more The PREDICTS project—Projecting Responses of Ecological Diversity In Changing Terrestrial Systems (www.predicts.org.uk)—has collated from published studies a large, reasonably representative database of comparable samples of biodiversity from multiple sites that differ in the nature or intensity of human impacts relating to land use. We have used this evidence base to develop global and regional statistical models of how local biodiversity responds to these measures. We describe and make freely available this 2016 release of the database, containing more than 3.2 million records sampled at over 26,000 locations and representing over 47,000 species. We outline how the database can help in answering a range of questions in ecology and conservation biology. To our knowledge, this is the largest and most geographically and taxonomically representative database of spatial comparisons of biodiversity that has been collated to date; it will be useful to researchers and international efforts wishing to model and understand the global status of biodiversity.
1. Monitoring global biodiversity is critical for understanding responses to anthropogenic change... more 1. Monitoring global biodiversity is critical for understanding responses to anthropogenic change, but biodiversity monitoring is often biased away from tropical, megadiverse areas that are experiencing more rapid environmental change. Acoustic surveys are increasingly used to monitor biodiversity change, especially for bats as they are important indicator species and most use sound to detect, localise and classify objects. However, using bat acoustic surveys for monitoring poses several challenges, particularly in megadiverse regions. Many species lack reference recordings, some species have high call similarity or differ in call detectability, and quantitative classification tools, such as machine learning algorithms, have rarely been applied to data from these areas. 2. Here, we collate a reference call library for bat species that occur in a megadiverse country, Mexico. We use 4685 search-phase calls from 1378 individual sequences of 59 bat species to create automatic species identification tools generated by machine learning algorithms (Random Forest). We evaluate the improvement in species-level classification rates gained by using hierarchical classifications, reflecting either taxonomic or ecological constraints (guilds) on call design, and examine how classification rate accuracy changes at different hierarchical levels (family, genus and guild). 3. Species-level classification of calls had a mean accuracy of 66%, and the use of hierarchies improved mean species-level classification accuracy by up to 6% (species within families 72%, species within genera 71Á2% and species within guilds 69Á1%). Classification accuracy to family, genus and guild-level was 91Á7%, 77Á8% and 82Á5%, respectively. 4. The bioacoustic identification tools we have developed are accurate for rapid biodiversity assessments in a megadiverse region and can also be used effectively to classify species at broader taxonomic or ecological levels. This flexibility increases their usefulness when there are incomplete species reference recordings and also offers the opportunity to characterise and track changes in bat community structure. Our results show that bat bioa-coustic surveys in megadiverse countries have more potential than previously thought to monitor biodiversity changes and can be used to direct further developments of bioacoustic monitoring programs in Mexico.
1. Monitoring global biodiversity is critical for understanding responses to anthropogenic change... more 1. Monitoring global biodiversity is critical for understanding responses to anthropogenic change, but biodiversity monitoring is often biased away from tropical, megadiverse areas that are experiencing more rapid environmental change. Acoustic surveys are increasingly used to monitor biodiversity change, especially for bats as they are important indicator species and most use sound to detect, localise and classify objects. However, using bat acoustic surveys for monitoring poses several challenges, particularly in megadiverse regions. Many species lack reference recordings, some species have high call similarity or differ in call detectability, and quantitative classification tools, such as machine learning algorithms, have rarely been applied to data from these areas. 2. Here, we collate a reference call library for bat species that occur in a megadiverse country, Mexico. We use 4685 search-phase calls from 1378 individual sequences of 59 bat species to create automatic species identification tools generated by machine learning algorithms (Random Forest). We evaluate the improvement in species-level classification rates gained by using hierarchical classifications, reflecting either taxonomic or ecological constraints (guilds) on call design, and examine how classification rate accuracy changes at different hierarchical levels (family, genus and guild). 3. Species-level classification of calls had a mean accuracy of 66%, and the use of hierarchies improved mean species-level classification accuracy by up to 6% (species within families 72%, species within genera 71Á2% and species within guilds 69Á1%). Classification accuracy to family, genus and guild-level was 91Á7%, 77Á8% and 82Á5%, respectively. 4. The bioacoustic identification tools we have developed are accurate for rapid biodiversity assessments in a megadiverse region and can also be used effectively to classify species at broader taxonomic or ecological levels. This flexibility increases their usefulness when there are incomplete species reference recordings and also offers the opportunity to characterise and track changes in bat community structure. Our results show that bat bioa-coustic surveys in megadiverse countries have more potential than previously thought to monitor biodiversity changes and can be used to direct further developments of bioacoustic monitoring programs in Mexico.
n order to compare the effectiveness of diurnal and nocturnal pollinators, we studied the reprodu... more n order to compare the effectiveness of diurnal and nocturnal pollinators, we studied the reproductive biology and pollinators of Tillandsia heterophylla E. Morren, an epiphytic tank bromeliad endemic to southeastern Mexico. Since anthesis in T. heterophylla is predominantly nocturnal but lasts until the following day, we hypothesized that this bromeliad would receive visits from both diurnal and nocturnal visitors, but that the nocturnal visitors would be the most effective pollinators, since they arrive first to the receptive flower, and that bats would be the most frequent nocturnal visitors, given the characteristics of the nectar. Flowering of T. heterophylla began in May and lasted until July. The species is fully self-compatible with an anthesis that lasts for approximately 15-16 h. Mean volume of nectar produced per flower was 82.21 µl with a mean sugar concentration of 6.33%. The highest volume and concentration of nectar were found at 20:00 h, with a subsequent decline in both cases to almost zero over the following 12 h period. Tillandsia heterophylla has a generalist pollination system, since at least four different morphospecies of visitors pollinate its flowers: bats, moths, hummingbirds and bees. Most of the pollinating visits corresponded to bats and took place in the early evening, when stigma receptivity had already begun; making bats the probable pollinator on most occasions. However, diurnal pollinators may be important as a “fail-safe” system by which to guarantee the pollination of T. heterophylla
"Con el propósito de contribuir con la iniciativa de elaborar un documento que uniformice la info... more "Con el propósito de contribuir con la iniciativa de elaborar un documento que uniformice la información taxonómica de todas las entidades federativas de México, en este trabajo se presenta la lista
sistemática actualizada de los mamíferos del estado de Yucatán. En el estado hay 128 especies, 97 géneros, 29 subfamilias, 37 familias y 13 órdenes. Los ordenes más ricos en especies son Chiroptera, Cetacea y Rodentia y los géneros con mayor número de especies Balaenoptera y Stenella. En cuanto a su distribución, 21 especies son endémicas de Mesoamérica y seis de México. En el estado se distribuyen 51 especies catalogadas en riesgo por la normativa mexicana, 38 incluidas en la Convención sobre el Comercio Internacional de Especies Amenazadas y 15 amenazadas a nivel global. En el trabajo se plantea la importancia de relacionar su diversidad y distribución con los instrumentos legales diseñados para su protección, conservación y aprovechamiento sustentable."
1. Undersampling is commonplace in biodiversity surveys of species-rich tropical assemblages in w... more 1. Undersampling is commonplace in biodiversity surveys of species-rich tropical assemblages in which rare taxa abound, with possible repercussions for our ability to implement surveys and monitoring programs in a cost-effective way.
2. We investigated the consequences of information loss due to species undersampling (missing subsets of species from the full species pool) in tropical bat surveys for the emerging patterns of species richness and compositional variation across sites.
3. For 27 bat assemblage datasets from across the tropics, we used correlations between original datasets and subsets with different numbers of species deleted either at random, or according to their rarity in the assemblage, to assess to what extent patterns in species richness and composition in data subsets are congruent with those in the initial dataset. We then examined to what degree high sample representativeness (r ≥ 0.8) was influenced by biogeographic region, sampling method, sampling effort, or structural assemblage characteristics.
4. For species richness, correlations between random subsets and original datasets were strong (r15 ≥ 0.8) with moderate (ca. 20%) species loss. Bias associated with information loss was greater for species composition; on average ca. 90% of species in random subsets had to be retained to adequately capture among-site variation. For non-random subsets, removing only the rarest species (on average ~10% of the full dataset) yielded strong correlations (r > 0.95) for both species richness and composition. Eliminating greater proportions of rare species resulted in weaker correlations and large variation in the magnitude of observed correlations among datasets.
5. Species subsets that comprised ca. 85% of the original set can be considered reliable
surrogates, capable of adequately revealing patterns of species richness and temporal or spatial turnover in many tropical bat assemblages. Our analyses thus demonstrate the 24 potential as well as limitations for reducing survey effort and streamlining sampling protocols, and consequently for increasing the cost-effectiveness in tropical bat surveys or monitoring programs. The dependence of the performance of species subsets on structural assemblage characteristics (total assemblage abundance, proportion of rare species), however, underscores the importance of adaptive monitoring schemes and of establishing surrogate performance on a site-by-site basis based on pilot surveys.
"The vesper mouse, Otonyctomys hatti, is a rare species, endemic to the Yucatan Peninsula, Mexico... more "The vesper mouse, Otonyctomys hatti, is a rare species, endemic to the Yucatan Peninsula, Mexico, of which the biology is practically unknown. This study reports for the first time on various aspects of the reproduction and postnatal development of
O. hatti observed in captivity. A reproductive colony was formed initially with four females (one pregnant) and a male, captured in the El Edén Ecological Reserve, Quintana Roo, Mexico. The mice were kept in living chambers and reproduction chambers and daily recordings were made of maternal conduct and developmental parameters in the young. In total, 15 young were born in eight litters. Mean litter size was 1.9 young and the sex ratio was not different to 1:1. The neonates weighed an average of 3.6 g and were altricial at birth. Development of the young was slow; the eyes opened between days 11-13, although hearing and sense of smell developed earlier (9-11 days). Consumption of solids began between days 14 and 18 and weaning took place around day 21. The time period between mating and birth of the litter was 31-32 days. The reproductive and postnatal developmental aspects of O. hatti were similar to those reported for the phylogenetically proximal species Nyctomys sumichrasti.
"
Forest fragmentation reduces the amount of forest cover and negatively affects the habitat qualit... more Forest fragmentation reduces the amount of forest cover and negatively affects the habitat quality of forest remnants. Landscape
attributes and habitat quality should therefore be evaluated together to improve our understanding of how fauna respond to
fragmentation. We evaluated how patch quality (vegetation structure) and landscape characteristics influence the abundance of
phytophagous bats in two contrasting types of landscape that differ in percent forest cover and matrix type: landscapes dominated
by man-made pastures and landscapes with large tracts of continuous forest (tropical semi-deciduous forest). Bats were sampled in
forest patches in both types of matrices, and for each matrix two sites with a cenote (water filled sink-holes, typical of the Yucatan)
and two with no cenotes were sampled. Sites with cenotes offer better habitat quality than sites without cenotes: the richness and
basal area of plants eaten (flower or fruit) by bats are higher in the forest vegetation surrounding them. At the landscape level,
phytophagous bat abundance was negatively correlated with the amount of forest cover and proximity to other forest fragments, but
positively correlated with forest edge density, patch density and landscape heterogeneity. At the patch level, bat abundance was
positively correlated with plant richness and the basal area of edible tree species. In the Yucatan’s agricultural landscapes the area
and spatial distribution of forest remnants are not the only variables affecting bats. Habitat patch quality and high heterogeneity of
land cover types are also important, and have a positive effect on phytophagous bat abundance and movement.
The PREDICTS project—Projecting Responses of Ecological Diversity In Changing Terrestrial Systems... more The PREDICTS project—Projecting Responses of Ecological Diversity In Changing Terrestrial Systems (www.predicts.org.uk)—has collated from published studies a large, reasonably representative database of comparable samples of biodiversity from multiple sites that differ in the nature or intensity of human impacts relating to land use. We have used this evidence base to develop global and regional statistical models of how local biodiversity responds to these measures. We describe and make freely available this 2016 release of the database, containing more than 3.2 million records sampled at over 26,000 locations and representing over 47,000 species. We outline how the database can help in answering a range of questions in ecology and conservation biology. To our knowledge, this is the largest and most geographically and taxonomically representative database of spatial comparisons of biodiversity that has been collated to date; it will be useful to researchers and international efforts wishing to model and understand the global status of biodiversity.
he PREDICTS project—Projec ng Responses of Ecological Diversity In Changing Terrestrial Systems (... more he PREDICTS project—Projec ng Responses of Ecological Diversity In Changing Terrestrial Systems (www.predicts.org.uk)—has collated from published studies a large, reasonably representa ve database of comparable samples of biodiversity from mul ple sites that di er in the nature or intensity of human impacts rela ng to land use. We have used this evidence base to develop global and regional sta s cal models of how local biodiversity responds to these measures. We describe and make freely available this 2016 release of the database, containing more than 3.2 million records sampled at over 26,000 loca ons and represen ng over 47,000 species. We outline how the database can help in answering a range of ques ons in ecology and conserva on biology. To our knowledge, this is the largest and most geographically and taxonomically representa ve database of spa al comparisons of biodiversity that has been collated to date; it will be useful to researchers and interna onal e orts wishing to model and understand the global status of biodiversity.
The PREDICTS project—Projecting Responses of Ecological Diversity In Changing Terrestrial Systems... more The PREDICTS project—Projecting Responses of Ecological Diversity In Changing Terrestrial Systems (www.predicts.org.uk)—has collated from published studies a large, reasonably representative database of comparable samples of biodiversity from multiple sites that differ in the nature or intensity of human impacts relating to land use. We have used this evidence base to develop global and regional statistical models of how local biodiversity responds to these measures. We describe and make freely available this 2016 release of the database, containing more than 3.2 million records sampled at over 26,000 locations and representing over 47,000 species. We outline how the database can help in answering a range of questions in ecology and conservation biology. To our knowledge, this is the largest and most geographically and taxonomically representative database of spatial comparisons of biodiversity that has been collated to date; it will be useful to researchers and international efforts wishing to model and understand the global status of biodiversity.
1. Monitoring global biodiversity is critical for understanding responses to anthropogenic change... more 1. Monitoring global biodiversity is critical for understanding responses to anthropogenic change, but biodiversity monitoring is often biased away from tropical, megadiverse areas that are experiencing more rapid environmental change. Acoustic surveys are increasingly used to monitor biodiversity change, especially for bats as they are important indicator species and most use sound to detect, localise and classify objects. However, using bat acoustic surveys for monitoring poses several challenges, particularly in megadiverse regions. Many species lack reference recordings, some species have high call similarity or differ in call detectability, and quantitative classification tools, such as machine learning algorithms, have rarely been applied to data from these areas. 2. Here, we collate a reference call library for bat species that occur in a megadiverse country, Mexico. We use 4685 search-phase calls from 1378 individual sequences of 59 bat species to create automatic species identification tools generated by machine learning algorithms (Random Forest). We evaluate the improvement in species-level classification rates gained by using hierarchical classifications, reflecting either taxonomic or ecological constraints (guilds) on call design, and examine how classification rate accuracy changes at different hierarchical levels (family, genus and guild). 3. Species-level classification of calls had a mean accuracy of 66%, and the use of hierarchies improved mean species-level classification accuracy by up to 6% (species within families 72%, species within genera 71Á2% and species within guilds 69Á1%). Classification accuracy to family, genus and guild-level was 91Á7%, 77Á8% and 82Á5%, respectively. 4. The bioacoustic identification tools we have developed are accurate for rapid biodiversity assessments in a megadiverse region and can also be used effectively to classify species at broader taxonomic or ecological levels. This flexibility increases their usefulness when there are incomplete species reference recordings and also offers the opportunity to characterise and track changes in bat community structure. Our results show that bat bioa-coustic surveys in megadiverse countries have more potential than previously thought to monitor biodiversity changes and can be used to direct further developments of bioacoustic monitoring programs in Mexico.
1. Monitoring global biodiversity is critical for understanding responses to anthropogenic change... more 1. Monitoring global biodiversity is critical for understanding responses to anthropogenic change, but biodiversity monitoring is often biased away from tropical, megadiverse areas that are experiencing more rapid environmental change. Acoustic surveys are increasingly used to monitor biodiversity change, especially for bats as they are important indicator species and most use sound to detect, localise and classify objects. However, using bat acoustic surveys for monitoring poses several challenges, particularly in megadiverse regions. Many species lack reference recordings, some species have high call similarity or differ in call detectability, and quantitative classification tools, such as machine learning algorithms, have rarely been applied to data from these areas. 2. Here, we collate a reference call library for bat species that occur in a megadiverse country, Mexico. We use 4685 search-phase calls from 1378 individual sequences of 59 bat species to create automatic species identification tools generated by machine learning algorithms (Random Forest). We evaluate the improvement in species-level classification rates gained by using hierarchical classifications, reflecting either taxonomic or ecological constraints (guilds) on call design, and examine how classification rate accuracy changes at different hierarchical levels (family, genus and guild). 3. Species-level classification of calls had a mean accuracy of 66%, and the use of hierarchies improved mean species-level classification accuracy by up to 6% (species within families 72%, species within genera 71Á2% and species within guilds 69Á1%). Classification accuracy to family, genus and guild-level was 91Á7%, 77Á8% and 82Á5%, respectively. 4. The bioacoustic identification tools we have developed are accurate for rapid biodiversity assessments in a megadiverse region and can also be used effectively to classify species at broader taxonomic or ecological levels. This flexibility increases their usefulness when there are incomplete species reference recordings and also offers the opportunity to characterise and track changes in bat community structure. Our results show that bat bioa-coustic surveys in megadiverse countries have more potential than previously thought to monitor biodiversity changes and can be used to direct further developments of bioacoustic monitoring programs in Mexico.
n order to compare the effectiveness of diurnal and nocturnal pollinators, we studied the reprodu... more n order to compare the effectiveness of diurnal and nocturnal pollinators, we studied the reproductive biology and pollinators of Tillandsia heterophylla E. Morren, an epiphytic tank bromeliad endemic to southeastern Mexico. Since anthesis in T. heterophylla is predominantly nocturnal but lasts until the following day, we hypothesized that this bromeliad would receive visits from both diurnal and nocturnal visitors, but that the nocturnal visitors would be the most effective pollinators, since they arrive first to the receptive flower, and that bats would be the most frequent nocturnal visitors, given the characteristics of the nectar. Flowering of T. heterophylla began in May and lasted until July. The species is fully self-compatible with an anthesis that lasts for approximately 15-16 h. Mean volume of nectar produced per flower was 82.21 µl with a mean sugar concentration of 6.33%. The highest volume and concentration of nectar were found at 20:00 h, with a subsequent decline in both cases to almost zero over the following 12 h period. Tillandsia heterophylla has a generalist pollination system, since at least four different morphospecies of visitors pollinate its flowers: bats, moths, hummingbirds and bees. Most of the pollinating visits corresponded to bats and took place in the early evening, when stigma receptivity had already begun; making bats the probable pollinator on most occasions. However, diurnal pollinators may be important as a “fail-safe” system by which to guarantee the pollination of T. heterophylla
"Con el propósito de contribuir con la iniciativa de elaborar un documento que uniformice la info... more "Con el propósito de contribuir con la iniciativa de elaborar un documento que uniformice la información taxonómica de todas las entidades federativas de México, en este trabajo se presenta la lista
sistemática actualizada de los mamíferos del estado de Yucatán. En el estado hay 128 especies, 97 géneros, 29 subfamilias, 37 familias y 13 órdenes. Los ordenes más ricos en especies son Chiroptera, Cetacea y Rodentia y los géneros con mayor número de especies Balaenoptera y Stenella. En cuanto a su distribución, 21 especies son endémicas de Mesoamérica y seis de México. En el estado se distribuyen 51 especies catalogadas en riesgo por la normativa mexicana, 38 incluidas en la Convención sobre el Comercio Internacional de Especies Amenazadas y 15 amenazadas a nivel global. En el trabajo se plantea la importancia de relacionar su diversidad y distribución con los instrumentos legales diseñados para su protección, conservación y aprovechamiento sustentable."
1. Undersampling is commonplace in biodiversity surveys of species-rich tropical assemblages in w... more 1. Undersampling is commonplace in biodiversity surveys of species-rich tropical assemblages in which rare taxa abound, with possible repercussions for our ability to implement surveys and monitoring programs in a cost-effective way.
2. We investigated the consequences of information loss due to species undersampling (missing subsets of species from the full species pool) in tropical bat surveys for the emerging patterns of species richness and compositional variation across sites.
3. For 27 bat assemblage datasets from across the tropics, we used correlations between original datasets and subsets with different numbers of species deleted either at random, or according to their rarity in the assemblage, to assess to what extent patterns in species richness and composition in data subsets are congruent with those in the initial dataset. We then examined to what degree high sample representativeness (r ≥ 0.8) was influenced by biogeographic region, sampling method, sampling effort, or structural assemblage characteristics.
4. For species richness, correlations between random subsets and original datasets were strong (r15 ≥ 0.8) with moderate (ca. 20%) species loss. Bias associated with information loss was greater for species composition; on average ca. 90% of species in random subsets had to be retained to adequately capture among-site variation. For non-random subsets, removing only the rarest species (on average ~10% of the full dataset) yielded strong correlations (r > 0.95) for both species richness and composition. Eliminating greater proportions of rare species resulted in weaker correlations and large variation in the magnitude of observed correlations among datasets.
5. Species subsets that comprised ca. 85% of the original set can be considered reliable
surrogates, capable of adequately revealing patterns of species richness and temporal or spatial turnover in many tropical bat assemblages. Our analyses thus demonstrate the 24 potential as well as limitations for reducing survey effort and streamlining sampling protocols, and consequently for increasing the cost-effectiveness in tropical bat surveys or monitoring programs. The dependence of the performance of species subsets on structural assemblage characteristics (total assemblage abundance, proportion of rare species), however, underscores the importance of adaptive monitoring schemes and of establishing surrogate performance on a site-by-site basis based on pilot surveys.
"The vesper mouse, Otonyctomys hatti, is a rare species, endemic to the Yucatan Peninsula, Mexico... more "The vesper mouse, Otonyctomys hatti, is a rare species, endemic to the Yucatan Peninsula, Mexico, of which the biology is practically unknown. This study reports for the first time on various aspects of the reproduction and postnatal development of
O. hatti observed in captivity. A reproductive colony was formed initially with four females (one pregnant) and a male, captured in the El Edén Ecological Reserve, Quintana Roo, Mexico. The mice were kept in living chambers and reproduction chambers and daily recordings were made of maternal conduct and developmental parameters in the young. In total, 15 young were born in eight litters. Mean litter size was 1.9 young and the sex ratio was not different to 1:1. The neonates weighed an average of 3.6 g and were altricial at birth. Development of the young was slow; the eyes opened between days 11-13, although hearing and sense of smell developed earlier (9-11 days). Consumption of solids began between days 14 and 18 and weaning took place around day 21. The time period between mating and birth of the litter was 31-32 days. The reproductive and postnatal developmental aspects of O. hatti were similar to those reported for the phylogenetically proximal species Nyctomys sumichrasti.
"
Forest fragmentation reduces the amount of forest cover and negatively affects the habitat qualit... more Forest fragmentation reduces the amount of forest cover and negatively affects the habitat quality of forest remnants. Landscape
attributes and habitat quality should therefore be evaluated together to improve our understanding of how fauna respond to
fragmentation. We evaluated how patch quality (vegetation structure) and landscape characteristics influence the abundance of
phytophagous bats in two contrasting types of landscape that differ in percent forest cover and matrix type: landscapes dominated
by man-made pastures and landscapes with large tracts of continuous forest (tropical semi-deciduous forest). Bats were sampled in
forest patches in both types of matrices, and for each matrix two sites with a cenote (water filled sink-holes, typical of the Yucatan)
and two with no cenotes were sampled. Sites with cenotes offer better habitat quality than sites without cenotes: the richness and
basal area of plants eaten (flower or fruit) by bats are higher in the forest vegetation surrounding them. At the landscape level,
phytophagous bat abundance was negatively correlated with the amount of forest cover and proximity to other forest fragments, but
positively correlated with forest edge density, patch density and landscape heterogeneity. At the patch level, bat abundance was
positively correlated with plant richness and the basal area of edible tree species. In the Yucatan’s agricultural landscapes the area
and spatial distribution of forest remnants are not the only variables affecting bats. Habitat patch quality and high heterogeneity of
land cover types are also important, and have a positive effect on phytophagous bat abundance and movement.
Actualmente gran parte de la biodiversidad del planeta se encuentra en elementos del paisaje modi... more Actualmente gran parte de la biodiversidad del planeta se encuentra en elementos del paisaje modificados por el hombre. Este hecho hace necesario evaluarlos como sitios de retención de biodiversidad. En un paisaje antropizado del Istmo de Tehuantepec, se registró la diversidad de murciélagos y su relación con los elementos del paisaje. El paisaje se describió usando técnicas de percepción remota y muestreos de vegetación; para el caso de los murciélagos se utilizó la captura directa por medio de redes de niebla. En total se identificaron seis elementos del paisaje: selva mediana subperennifolia (SMS), selva baja caducifolia (SBC), acahual de selva baja caducifolia (ASBC), bosque de galería (BG), franjas de vegetación (FV) y áreas agropecuarias (AGRO). Se identificó un gradiente de diversidad vegetal, teniendo a la SMS como la más diversa y las áreas agropecuarias como las menos. Para los murciélagos en el bosque de galería se registró una mayor riqueza mientras que el área agropecuaria fue la más pobre. Se resalta la SMS donde se encontraron especies características de interior de bosque y consideradas como indicadoras. Este estudio aporta evidencia de la importancia de la conservación de fragmentos remanentes de vegetación conservada y su interconectividad con otros elementos a una escala de paisaje, como un factor clave para el mantenimiento de grupos biológicos como los murciélagos.
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million records sampled at over 26,000 locations and representing over 47,000 species. We outline how the database can help in answering a range of questions in ecology and conservation biology. To our knowledge, this is the largest and most geographically and taxonomically representative database of spatial comparisons of biodiversity that has been collated to date; it will be useful to researchers and international efforts wishing to model and understand the global status of biodiversity.
sistemática actualizada de los mamíferos del estado de Yucatán. En el estado hay 128 especies, 97 géneros, 29 subfamilias, 37 familias y 13 órdenes. Los ordenes más ricos en especies son Chiroptera, Cetacea y Rodentia y los géneros con mayor número de especies Balaenoptera y Stenella. En cuanto a su distribución, 21 especies son endémicas de Mesoamérica y seis de México. En el estado se distribuyen 51 especies catalogadas en riesgo por la normativa mexicana, 38 incluidas en la Convención sobre el Comercio Internacional de Especies Amenazadas y 15 amenazadas a nivel global. En el trabajo se plantea la importancia de relacionar su diversidad y distribución con los instrumentos legales diseñados para su protección, conservación y aprovechamiento sustentable."
2. We investigated the consequences of information loss due to species undersampling (missing subsets of species from the full species pool) in tropical bat surveys for the emerging patterns of species richness and compositional variation across sites.
3. For 27 bat assemblage datasets from across the tropics, we used correlations between original datasets and subsets with different numbers of species deleted either at random, or according to their rarity in the assemblage, to assess to what extent patterns in species richness and composition in data subsets are congruent with those in the initial dataset. We then examined to what degree high sample representativeness (r ≥ 0.8) was influenced by biogeographic region, sampling method, sampling effort, or structural assemblage characteristics.
4. For species richness, correlations between random subsets and original datasets were strong (r15 ≥ 0.8) with moderate (ca. 20%) species loss. Bias associated with information loss was greater for species composition; on average ca. 90% of species in random subsets had to be retained to adequately capture among-site variation. For non-random subsets, removing only the rarest species (on average ~10% of the full dataset) yielded strong correlations (r > 0.95) for both species richness and composition. Eliminating greater proportions of rare species resulted in weaker correlations and large variation in the magnitude of observed correlations among datasets.
5. Species subsets that comprised ca. 85% of the original set can be considered reliable
surrogates, capable of adequately revealing patterns of species richness and temporal or spatial turnover in many tropical bat assemblages. Our analyses thus demonstrate the 24 potential as well as limitations for reducing survey effort and streamlining sampling protocols, and consequently for increasing the cost-effectiveness in tropical bat surveys or monitoring programs. The dependence of the performance of species subsets on structural assemblage characteristics (total assemblage abundance, proportion of rare species), however, underscores the importance of adaptive monitoring schemes and of establishing surrogate performance on a site-by-site basis based on pilot surveys.
O. hatti observed in captivity. A reproductive colony was formed initially with four females (one pregnant) and a male, captured in the El Edén Ecological Reserve, Quintana Roo, Mexico. The mice were kept in living chambers and reproduction chambers and daily recordings were made of maternal conduct and developmental parameters in the young. In total, 15 young were born in eight litters. Mean litter size was 1.9 young and the sex ratio was not different to 1:1. The neonates weighed an average of 3.6 g and were altricial at birth. Development of the young was slow; the eyes opened between days 11-13, although hearing and sense of smell developed earlier (9-11 days). Consumption of solids began between days 14 and 18 and weaning took place around day 21. The time period between mating and birth of the litter was 31-32 days. The reproductive and postnatal developmental aspects of O. hatti were similar to those reported for the phylogenetically proximal species Nyctomys sumichrasti.
"
attributes and habitat quality should therefore be evaluated together to improve our understanding of how fauna respond to
fragmentation. We evaluated how patch quality (vegetation structure) and landscape characteristics influence the abundance of
phytophagous bats in two contrasting types of landscape that differ in percent forest cover and matrix type: landscapes dominated
by man-made pastures and landscapes with large tracts of continuous forest (tropical semi-deciduous forest). Bats were sampled in
forest patches in both types of matrices, and for each matrix two sites with a cenote (water filled sink-holes, typical of the Yucatan)
and two with no cenotes were sampled. Sites with cenotes offer better habitat quality than sites without cenotes: the richness and
basal area of plants eaten (flower or fruit) by bats are higher in the forest vegetation surrounding them. At the landscape level,
phytophagous bat abundance was negatively correlated with the amount of forest cover and proximity to other forest fragments, but
positively correlated with forest edge density, patch density and landscape heterogeneity. At the patch level, bat abundance was
positively correlated with plant richness and the basal area of edible tree species. In the Yucatan’s agricultural landscapes the area
and spatial distribution of forest remnants are not the only variables affecting bats. Habitat patch quality and high heterogeneity of
land cover types are also important, and have a positive effect on phytophagous bat abundance and movement.
million records sampled at over 26,000 locations and representing over 47,000 species. We outline how the database can help in answering a range of questions in ecology and conservation biology. To our knowledge, this is the largest and most geographically and taxonomically representative database of spatial comparisons of biodiversity that has been collated to date; it will be useful to researchers and international efforts wishing to model and understand the global status of biodiversity.
sistemática actualizada de los mamíferos del estado de Yucatán. En el estado hay 128 especies, 97 géneros, 29 subfamilias, 37 familias y 13 órdenes. Los ordenes más ricos en especies son Chiroptera, Cetacea y Rodentia y los géneros con mayor número de especies Balaenoptera y Stenella. En cuanto a su distribución, 21 especies son endémicas de Mesoamérica y seis de México. En el estado se distribuyen 51 especies catalogadas en riesgo por la normativa mexicana, 38 incluidas en la Convención sobre el Comercio Internacional de Especies Amenazadas y 15 amenazadas a nivel global. En el trabajo se plantea la importancia de relacionar su diversidad y distribución con los instrumentos legales diseñados para su protección, conservación y aprovechamiento sustentable."
2. We investigated the consequences of information loss due to species undersampling (missing subsets of species from the full species pool) in tropical bat surveys for the emerging patterns of species richness and compositional variation across sites.
3. For 27 bat assemblage datasets from across the tropics, we used correlations between original datasets and subsets with different numbers of species deleted either at random, or according to their rarity in the assemblage, to assess to what extent patterns in species richness and composition in data subsets are congruent with those in the initial dataset. We then examined to what degree high sample representativeness (r ≥ 0.8) was influenced by biogeographic region, sampling method, sampling effort, or structural assemblage characteristics.
4. For species richness, correlations between random subsets and original datasets were strong (r15 ≥ 0.8) with moderate (ca. 20%) species loss. Bias associated with information loss was greater for species composition; on average ca. 90% of species in random subsets had to be retained to adequately capture among-site variation. For non-random subsets, removing only the rarest species (on average ~10% of the full dataset) yielded strong correlations (r > 0.95) for both species richness and composition. Eliminating greater proportions of rare species resulted in weaker correlations and large variation in the magnitude of observed correlations among datasets.
5. Species subsets that comprised ca. 85% of the original set can be considered reliable
surrogates, capable of adequately revealing patterns of species richness and temporal or spatial turnover in many tropical bat assemblages. Our analyses thus demonstrate the 24 potential as well as limitations for reducing survey effort and streamlining sampling protocols, and consequently for increasing the cost-effectiveness in tropical bat surveys or monitoring programs. The dependence of the performance of species subsets on structural assemblage characteristics (total assemblage abundance, proportion of rare species), however, underscores the importance of adaptive monitoring schemes and of establishing surrogate performance on a site-by-site basis based on pilot surveys.
O. hatti observed in captivity. A reproductive colony was formed initially with four females (one pregnant) and a male, captured in the El Edén Ecological Reserve, Quintana Roo, Mexico. The mice were kept in living chambers and reproduction chambers and daily recordings were made of maternal conduct and developmental parameters in the young. In total, 15 young were born in eight litters. Mean litter size was 1.9 young and the sex ratio was not different to 1:1. The neonates weighed an average of 3.6 g and were altricial at birth. Development of the young was slow; the eyes opened between days 11-13, although hearing and sense of smell developed earlier (9-11 days). Consumption of solids began between days 14 and 18 and weaning took place around day 21. The time period between mating and birth of the litter was 31-32 days. The reproductive and postnatal developmental aspects of O. hatti were similar to those reported for the phylogenetically proximal species Nyctomys sumichrasti.
"
attributes and habitat quality should therefore be evaluated together to improve our understanding of how fauna respond to
fragmentation. We evaluated how patch quality (vegetation structure) and landscape characteristics influence the abundance of
phytophagous bats in two contrasting types of landscape that differ in percent forest cover and matrix type: landscapes dominated
by man-made pastures and landscapes with large tracts of continuous forest (tropical semi-deciduous forest). Bats were sampled in
forest patches in both types of matrices, and for each matrix two sites with a cenote (water filled sink-holes, typical of the Yucatan)
and two with no cenotes were sampled. Sites with cenotes offer better habitat quality than sites without cenotes: the richness and
basal area of plants eaten (flower or fruit) by bats are higher in the forest vegetation surrounding them. At the landscape level,
phytophagous bat abundance was negatively correlated with the amount of forest cover and proximity to other forest fragments, but
positively correlated with forest edge density, patch density and landscape heterogeneity. At the patch level, bat abundance was
positively correlated with plant richness and the basal area of edible tree species. In the Yucatan’s agricultural landscapes the area
and spatial distribution of forest remnants are not the only variables affecting bats. Habitat patch quality and high heterogeneity of
land cover types are also important, and have a positive effect on phytophagous bat abundance and movement.
de vegetación (FV) y áreas agropecuarias (AGRO). Se identificó un gradiente de diversidad vegetal, teniendo a la SMS como la más diversa y las áreas agropecuarias como las menos. Para los murciélagos en el bosque de galería se registró una mayor riqueza mientras que
el área agropecuaria fue la más pobre. Se resalta la SMS donde se encontraron especies características de interior de bosque y consideradas como indicadoras. Este estudio aporta evidencia de la importancia de la conservación de fragmentos remanentes de vegetación conservada y su interconectividad con otros elementos a una escala de paisaje, como un
factor clave para el mantenimiento de grupos biológicos como los murciélagos.