Molecular detection of avian hemoparasites (Plasmodium and Haemoproteus) in resident and migratory birds from an urban fragment of tropical dry forest in northern Colombia.

Bats are hosts of a high taxonomic diversity of ectoparasites. Six hundred eighty seven insect species have been reported as bat ectoparasites, belonging to orders Dermaptera, Lepidoptera, Diptera and Siphonaptera (Marshall 1982). This study lists an inventory of bat ectoparasites found in fragments of Tropical Dry Forest on the Caribbean coast of Colombia. The study was conducted in the Department of Cordoba in four farms with fragments of Tropical Dry Forest. Bats were captured using mist nets and were collected and stored in plastic bags for subsequent examination in the laboratory. Ectoparasites were stored in alcohol and identified using a stereo microscope and taxonomic keys. Two hundred fifty one bats belonging to 21 species were captured. The most abundant family was Phyllostomidae, followed by Emballonuridae, Noctilionidae, Vespertilionidae and Molossidae. Twelve genera of ectoparasites were found, belonging to families Streblidae, Nycteribiidae and Polyctenidae. Streblidae was the most abundant family and included the largest number of species. Thirty five percent of bats examined were hosts to at least one ectoparasite species. In this study, carried out in fragments of tropical dry forest in Cordoba, Colombia, we recorded dipterans in 17 out of 21 bat species. Hemypteran ectoparasites of the family Polyctenidae were found in Molossus molossus only. Eighty seven individual dipterans were found among 51 Carollia perspicillata specimens, which is consistent with the high parasitism levels previously reported. The bat species C. brevicauda, P. discolor, U. bilobatum and C. perspicillata carried the highest number of ectoparasite species.

Abstract: The tropical dry forest is under constant threat from many anthropic activities which are conducted indiscriminately, modifying the forest, and therefore, affecting species that are closely related to its phenology, such as longhorned beetles (Cerambycidae). The spatio-temporal variation of the cerambycid diversity in two fragments of tropical dry forest (Reserva Campesina la Montaña and La Flecha) in the Caribbean region of Colombia was analyzed. At each locality, four squared plots were delimited, and the beetles were collected with fruit traps, beating sheets and manual capture, and with light traps in the center. Five hundred eighty-seven specimens representing 128 species were collected, of which members of the tribe Ectenessini (Cerambycinae) were the most abundant. At the subfamily level, Cerambycinae was the most abundant (465 specimens) and diverse (73 species), followed by Lamiinae and Prioninae. The highest values of richness (110 species), abundance (428), biomass (21.18 g), and as well as the highest values of true diversity (1D= 73.44, 2D= 34.30) were found during the first precipitations. Regarding beta diversity, temporal variation was determined and mainly explained by a high percentage of turnover (> 70%). Lastly, the high diversity of Cerambycidae was associated with high values of relative humidity and canopy cover during the rainy season. This showed that the structure of the cerambycid community in the tropical dry forest of the Caribbean region of Colombia depends on these variables, which are closely related to precipitation.

We present a commented taxonomic list of the reptiles found during herpetological surveys carried out in an isolated fragment of tropical dry forest located in the municipality of San Francisco, Zulia state, northwestern Venezuela between January-December 2011. We report a total of 24 species belonging to the order Squamata, distributed in 12 families and 21 genera. Colubridae is the most diverse family with six species, followed by Dipsadidae (four species), Boidae, Gymnophthalmidae, Phyllodactylidae and Teiidae with two species each, and finally Dactyloidae, Iguanidae, Elapidae, Gekkonidae, Sphaerodactylidae and Viperidae with a single species each. The species composition at this site matches what would be expected in a tropical dry forest in the region. Our study suggests that this isolated tropical dry forest fragment is the last refuge of the herpetofauna that once occupied much of the dry forests of the northern Maracaibo basin and should therefore be considered for conservation purposes.

Birds are important hosts in the life cycle of some species of ticks. In Colombia, there are few eco-epidemiological studies of tick-borne diseases; the existing ones have been focused on areas where unusual outbreaks have occurred. This study describes the identification of ticks collected from birds and vegetation, and the detection of bacteria in those ticks and in blood samples from birds in an urban fragment of tropical dry forest in the department of Magdalena, Colombia. Bird sampling was carried out monthly in 2021, and 367 birds, distributed among 41 species, were captured. All collected ticks were identified as Amblyomma sp. or Amblyomma dissimile. The presence of rickettsiae in ticks collected from birds was evaluated by molecular analysis of the gltA, ompA and sca1 genes. 16S rRNA meta-taxonomy was used to evaluate rickettsiae in ticks collected from vegetation and in blood samples from birds. The presence of the species "Candidatus Rickettsia colombianensi" was detected in ticks from birds. Bacteria of the family Rickettsiacea was the most abundant in ticks collected from vegetation. Bacteria of the families Staphylococcaceae, Comamonadaceae and Pseudomonadaceae were prevalent in the samples of blood from birds. Rickettsia spp. was also detected in low abundance in some of the bird blood samples.

Breeding systems and dispersal mechanisms of plants (≥ 2.5 cm dbh) were examined in fragments of tropical dry forest in Central America to identify life-history characteristics associated with rarity. In particular, the richness and abundance of dioecious and mammal-dispersed trees and shrubs were examined to identify potential associations with precipitation, anthropogenic disturbance, and area. Plots totalling 1000 m2 per site were established in seven nature reserves in Costa Rica (two sites) and Nicaragua (five sites). Overall, tropical dry forests of Central America have a similar proportion of dioecious species to other lowland neotropical forests and a similar proportion of wind-dispersed plants to other tropical dry forests around the world. However, the number of dioecious and mammal-dispersed species declined with decreasing forest cover within each reserve. Although dioecious species were rare in smaller forest fragments, some of these species will not be threatened with regional extinction because they are early successional plants, they have large geographic ranges, and they are not restricted to the tropical dry forest life zone. Mammal-dispersed plants were rare in small fragments, but it is not clear whether this was due to the loss of dispersal vectors or other life-history characteristics.

The lack of information on how primates respond to habitat fragmentation across a variety of ecosystems and regions hampers conservation efforts in the fragmented landscapes where populations are most threatened. We investigated the status of primates in the highly fragmented forests of southwestern Nicaragua, a region containing some of Central America’s few remaining patches of tropical dry forest. We surveyed primates in two areas, the Chococente Wildlife Refuge comprising the country’s largest remaining fragments of tropical dry forest, and an area of Rivas just north of the Costa Rican border, where tropical dry forest exists in much smaller, more isolated patches without formal protection. Of the three species found in Nicaragua, howler monkeys (Alouatta palliata) were least affected by fragmentation remaining relatively abundant in both areas. However, capuchins (Cebus capucinus) and spider monkeys (Ateles geoffroyi) were far less abundant and have suffered local extinctions both inside and outside of protected areas. Interestingly, our data suggest that all three species are currently least threatened in the human-dominated landscape on the Rivas Isthmus, the more fragmented study region where forests receive no official protection. In spite of extensive fragmentation, southwestern Nicaragua’s remaining tropical dry forests may maintain a functioning metapopulation of primates, including populations of the endangered spider monkey. However, reasons why the endangered spider monkey is more common in the more fragmented region are unclear. Our results demonstrate both the surprising ability of primates to survive in highly modified landscapes, and the critical importance of coordinating conservation efforts with private landowners, local communities, and other stakeholders. Planning for primate conservation in such anthropogenic landscapes must consider historical factors and larger spatial context. In Nicaragua, the local NGO Paso Pacifico has adopted the spider monkey as a flagship species, and is working extensively with landowners and local communities to conserve this species and the forest fragments in which it lives.

Spatial and temporal variation in the diversity of ants in four urban fragments of the tropical dry forest in the city of Santa Marta was evaluated. The fragments were sampled four times in the dry and rainy season, from October 2019 to January 2020, using pitfall traps, mini-Winkler bags, baits, and manual collection. Both alpha and beta taxonomic diversity and their components were quantified. The functional groups were established based on proposals for Neotropical ant species. A total of 7 subfamilies, 37 genera, and 84 species were collected. Richness varied spatially from 33 to 61 species, but between the two seasons it was 72 and 76 species. Sites N01 and N02 had greater diversity than N03 and N04. In all the fragments, soil ants were dominated by Ectatomma ruidum, but litter ants showed a structure with less dominant species. The dissimilarity between fragments was 60–80%, attributable mainly to turnover (50–70%) but not to nestedness (10%). Seventeen functional groups were identified. Taxonomic diversity of ants in urban fragments in Santa Marta showed marked spatial variation, without influence from the seasons. Despite taxonomic turnover, there was broad similarity in functional groups between the fragments, indicating ecological equivalence of species between the ant assemblages.

Tropical dry forests have been reduced to less than 0.1% of their original expanse on the Pacific side of Central America and are considered by some to be the most endangered ecosystem in the lowland tropics. Plots 1000 m2 were established in seven tropical dry forests in Costa Rica and Nicaragua in order to compare levels of species richness to other Neotropical dry forest sites and to identify environmental variables associated with species richness and abundance. A total of 204 species and 1484 individuals ≥ 2.5 cm were encountered. Santa Rosa National Park was the richest site with the highest family (33), genera (69), and species (75) diversity of all sites. Species richness and forest structure were significantly different between sites. Fabaceae was the dominant tree and shrub family at most sites, but no species was repeatably dominant based on number of stems in all fragments of tropical dry forest. Central American dry forests had similar species richness when compared to other Neotropical forests. There was no correlation between forest cover within reserves, or precipitation and plant species richness. There was a significant correlation between anthropogenic disturbance (intensity and frequency of fire, wood collection, grazing) and total species richness, tree and shrub species richness, and liana abundance. These results suggest controlling levels on anthropogenic disturbance within reserves should be a high priority for resource managers in Central America. Further research in forest fragments which examine individual and a combination of disturbance agents would help clarify the importance of anthropogenic disturbance on species richness and abundance.

We examined vegetation structure and woody species diversity in relation to 14 environmental and anthropogenic factors in ten tropical dry forest (TDF) fragments in central Veracruz, Mexico. The basal area of the canopy (30.2 ± 2.11 m2/ha) and understory (1.96 ± 0.12 m2/ha) trees was similar, but density (1,014 ± 104 and 2,532 ± 227 individuals/ha, respectively) differed among sites. We recorded 98 canopy, 77 understory, and 60 seedling species. Richness was 24–45 species per site, Fisher’s alpha and Shannon’s indices increased with site altitude. Chao Jaccard indices revealed high species turnover, and a consistently higher similarity within the sites at the lowest and within the highest elevation sites. Ordination identified altitude, aspect, slope, water proximity, cattle and trails as significant explanatory variables of species patterns, and showed that sites at lower elevations were clearly separated from the other sites. Environmental heterogeneity alone did not control species diversity distribution, but species were affected by environmental filters at different stages in their life cycle, e.g., water proximity was significant for saplings and seedlings but not for adults. Anthropogenic disturbances act synergistically, e.g., trails played a key role in determining structure and tree diversity patterns. An important finding is that human disturbance diminishes species diversity in this TDF, but sites at lower elevations were more disturbed and less diverse, therefore we need to study how environmental factors would act if there were no anthropogenic disturbance.

The temporal variation in the diversity of Polistinae was analyzed in three fragments of tropical dry forest (TDF) in the Colombian Caribbean (Reserva Campesina la Montaña = RCM, Reserva La Flecha = RCF and Finca La Clarita = FLC). Three transects, each measuring 250 × 20 m and spaced 200 m apart, were established per site. Within each transect, six collection points were marked, each separated by 50 m. The social wasps were captured using baited traps and entomological nets. A total of 2274 wasps were collected across the three TDF fragments, identified into 11 genera and 24 species. The most diverse genus was Polybia, followed by Polistes and Agelaia. The highest species richness among fragments was recorded at RLF (22), while the lowest was at RCM and FLC (10). Seasonally, RLF exhibited the highest richness (17) during the rainy season, whereas the lowest richness was observed at RCM during the dry season (5). According to diversity profiles, the highest value of the effective number of species (0D) was recorded at RLF during the rainy season (15), and the lowest (2) during the dry season at RCM. This same pattern was observed for the other two orders of diversity (1D and 2D). In terms of beta diversity, a high dissimilarity was observed among the three locations, driven by both nesting and species turnover, while from a temporal perspective (dry-rainy seasons), species turnover was predominant. The diversity variation of the social wasps is associated with changes in humidity due to the onset of the rainy season, demonstrating that seasonal changes in these variables within TDF fragments are crucial in the dynamics of social wasp communities.

Drastic changes in dry tropical forest result in the loss of biological components and reveal the importance of studies on the biology of species living in it. The present study aimed to describe seed morphoanatomy, germination and post-seminal development of Bromeliaceae species in fragments of tropical dry forest in Sucre, Colombia. Seven species representing Bromelia and Tillandsia genera were evaluated. The results provide characteristics related to the habitat of each species and contribute to distinguish the genera evaluated: fruit and seed measurements, seed shape, plumose appendage, testa characteristics, and the aleurone layer, embryo endosperm ratio, types of reserves, constriction zone in the embryo and type of post-seminal development. Characteristics of plumose appendages and the presence of vascular bundles in the embryo also contribute to distinguish Tillandsia species. In T. elongata and T. flexuosa, high number of seeds per fruit (> 100), morphoanatomical aspects, high germination (> 92%) and plant formation (> 77%) percentages, and higher germination rate values (> 4.5) give them the potential capacity for establishment in this environment. Our results provide information with taxonomic and ecological relevance for bromeliads in dry tropical forest.

Basic diversity studies of small non-volant mammals are scarce in western Ecuador, evidencing a knowledge gap regarding the mammalian fauna in the region. These organisms play key roles in important ecological processes and may be affected by several anthropogenic factors. Herein we report the results of a rapid assessment of marsupials and rodents of Bosque Protector Cerro Blanco (Guayas province), a fragment of dry forest surrounded by urban development. Between October 2016 and March 2017, we trapped rodents and marsupials with Sherman and Tomahawk live traps; also, we conducted direct observations and searched for skeletal remains. We recorded nine species of small non-volant mammals, seven native and two invasive. The marsupial Marmosa simonsi was the most frequently captured species. We reported three previously unrecorded species for this reserve: Sigmodon peruanus, Aegialomys baroni, and Rhipidomys latimanus. We recommend continued monitoring of the mammalian fauna of Cerro Blanco using alternative techniques such as pitfall traps, canopy live traps, and analysis of owl pellets. These efforts will permit a better understanding of the marsupial and rodent assemblage in this important site for biodiversity conservation in coastal Ecuador, a region that unfortunately faces intense human pressure.

Simple SummaryTropical dry forests are highly threatened by human activities such as agriculture, livestock, and selective logging. These activities have resulted in fragments of tropical dry forest under different successional stages that negatively affect the interaction between plants and fruit-eating birds. We analyzed the consumption of the fruits of zoochorous trees by birds during the dry season in a tropical dry forest and evaluated whether the horizontal and vertical structure of these trees explains fruit consumption. We also related the bird body mass and fruit size removed from zoochorous trees. We found that the tree structure can influence the visitation of fruit-eating birds, and therefore, the number of fruits consumed as the succession progresses. There was a relationship between fruit sizes and bird body mass in the successional gradient. Our results indicate that structural and fruit traits of zoochorous trees drive foraging preferences of fruit-eating birds, whose interactions in different successional stages can help to reverse the negative effects of fragmentation in tropical dry forests of the study area.Tropical dry forests (TDFs) are affected by land-use changes. These modifications impact their composition and arboreal structure, as well as the availability of food for several bird groups. In this study, we evaluated the foraging preferences in zoochorous trees of fruit-eating birds during the dry season of the year in three successional stages (early, intermediate, and mature) of TDFs in southern Mexico. The fruits of these trees are important in the diet of several birds during the dry season, a period during which food resources are significantly reduced in TDFs. We estimated foliar cover (FC) and foliage height diversity (FHD) of zoochorous trees in 123 circular plots. These variables were recognized as proxies of food availability and tree productivity. Foraging preferences were evaluated at the community level, by frugivore type, and by bird species. We evaluated the effect of the structural variables and the fruit size of zoochorous plants on fruit removal by birds and related the bird body mass and fruit size removed in the successional gradient. A total of 14 zoochorous tree species and 23 fruit-eating bird species were recorded along the successional gradient. Intermediate and mature stages showed greater fruit removal. The birds removed mainly B. longipes fruits across the three successional stages. The FHD and fruit size were important drivers in the selection of zoochorous trees and fruit removal by fruit-eating birds. Fruit size and bird body mass were positively related along the successional gradient. The results suggest that fruit removal by fruit-eating birds in the successional gradient can promote the demographic dynamics of several zoochorous tree species, especially of Bursera spp. along the TDFs.

The establishment of extensive livestock systems in the Colombian Caribbean Region has historically generated a strong loss of the tropical dry forest (TDF) with negative effects on biodiversity. Currently, the implementation of silvopastoral systems (SPS) has been proposed with strategy to curb the loss of biodiversity caused by the conventional management system (CS). The objective was to evaluate the effect of SPS and CS of extensive livestock on the assemblage of bats associated with fragments of TDF. During a continuous year and a sampling effort of 30,240 h-net/night, the structure and composition of bat assemblage between SPS and CS were compared. 2788 bats belonging to six families, 23 genera, and 39 species were captured. The Phyllostomidae family presented the highest species richness (S = 30), with the greatest abundance in the Stenodermatinae subfamily (n = 1543). Bat assemblage in the SPS fragments was more equitable; and the relative abundance per species, per genera, and per foraging guilds was also significantly higher. The capture success showed significant variations between the climatic seasons (dry and rainy). The rate of species turnover was higher in the CS fragments. The species Artibeus planirostris, Artibeus lituratus, Carollia perspicillata, Carollia castanea, Phyllostomus discolor, Dermanura phaeotis, Uroderma convexum, Glossophaga soricina, C. brevicauda, and Sturnira lilium accounted for 92% of the captures. In conclusion, frugivorous bats were more abundant in the SPS, type of extensive livestock management that can generate greater temporal stability of bat assemblage. This research provides the first scientific evidence of the positive effect of silvopastoral management on the diversity of bats in tropical dry forest areas of the Colombian Caribbean region.

The phytogeographic and floristic connections of the “Montes de Maria” (MM: north of Colombia) were analyzed through Geographic Information Systems, at worldwide, Neotropical and in Colombia scales in order to determine its geographical origin and floristic affinities. We estimated that genera are mostly of the Neotropical (74%) and Nearctic (26%) origin. At the Neotropical level, MM is located at the Pacific dominion and shares species with the Mesoamerican dominion. In addition, shares species with the Chaquena, Antilles subregions, and the South American and Mexican transition zones. At the regional level, the MM is located between Guajira and Magdalena provinces, although is floristically more similar to Guajira province. MM shape a floristic unit together with other fragments of dry forest in the Colombian Caribbean, which is highly related to dry forests of the inter-Andean valleys. In addition, the floristic origin of MM is associated to dry flora of Mesoamerica, nonetheless it was also influenced by the Amazonian and the Sabana province.