Caatinga Of Northeastern Brazil Research Articles

Connections between the Atlantic and the Amazonian forest avifaunas represent distinct historical events

There is much evidence to support past contact between the Atlantic and the Amazon forests through the South American dry vegetation diagonal, but the spatiotemporal dynamics of this contact still need to be investigated to allow a better understanding of its biogeographic implications for birds. Here, we combined phylogenetic data with distributional data using a supermatrix approach in order to depict the historical connection dynamics between these biomes for New World suboscines. We examined the variation in divergence time and then compared the spatial distributions of taxon pairs representing old and recent divergences. Our results pointed to two distinct spatiotemporal pathways connecting the Atlantic and the Amazonian forests in the past: (1) old connections (middle to late Miocene) through the current southern Cerrado and Mato Grosso and the transition towards the Chaco and palm savannas of Bolivia and Paraguay; (2) young connections (Pliocene to Pleistocene) that possibly occurred through the Cerrado and Caatinga in northeastern Brazil. We suggest that the main events that played important roles in these connections were geotectonic events during the late Tertiary associated with the uplift of the Andes (old connections) and Quaternary climate changes that promoted the expansion of gallery forest through the Cerrado and Caatinga in northeastern Brazil (young connections). Our results provide the first general temporal and spatial model of how the Atlantic and Amazonian forests were connected in the past, which was derived using bird data.

Estudo comparativo da madeira de Mimosa ophthalmocentra Mart. ex Benth e Mimosa tenuiflora (Willd.) Poir. (Fabaceae-Mimosoideae) na caatinga nordestina

Pela importância econômica da madeira de algumas espécies do gênero Mimosa L. ocorrentes na caatinga nordestina e pelo fato de Mimosa ophthalmocentra Mart. ex Benth. (jurema-de-imbira), às vezes, ser confundida com Mimosa tenuiflora (Willd.) Poir. (jurema-preta) ou vice-versa, este trabalho objetivou apresentar novos dados referentes à anatomia e densidade básica da madeira das duas espécies, visando oferecer subsídio para identificação das duas espécies, identificar caracteres anatômicos da madeira relacionando-os com o ambiente caatinga e apresentar o potencial energético que sua madeira possui. O estudo anatômico e a determinação da densidade da madeira foram realizados com amostras ao nível do peito (1,30 m acima do solo) e em dois galhos com diferentes diâmetros, de espécimes ocorrentes nos municípios de Serra Talhada e Sertânia, Pernambuco, Brasil. As espécies apresentam distinção expressa através do tipo de casca, coloração do cerne e do alburno, além das características peculiares da madeira. Mimosa ophthalmocentra apresenta camadas de crescimento distintas, constituídas por linhas de parênquima axial contendo cristais, parênquima axial escasso e menor quantidade de raios por mm². Já Mimosa tenuiflora apresenta camadas de crescimento distintas, porém sem cristais, parênquima axial vasicêntrico, em faixas ou aliforme confluente, e maior percentagem de raios. Ambas apresentam algumas estruturas da madeira com as características anatômicas comuns às diversas espécies do gênero Mimosa, contribuindo assim para uma melhor caracterização do gênero. Pelos parâmetros anatômicos da madeira e pela elevada densidade básica (>0,84 g/cm³), concluiu-se que as duas espécies apresentam perspectivas seguras para a produção de álcool combustível e carvão vegetal desde a fase de lenho juvenil. Mimosa ophthalmocentra apresenta maior potencial energético, pela maior percentagem de fibras e por possuir parênquima escasso e menor percentagem de raios.

Bromatologic composition of the herbaceous species of the Northeastern Brazil Caatinga

The objective of this work was to evaluate the chemical composition of the pool and of four species of caatinga herbaceous vegetation in the rainy and dry seasons. The experiment was conducted in three selected shrub areas at different levels of conservation. Four samples of each species (Arachis pintoi, Boerhavia diffusa, Heliotropium ternatum, Aristida adscensionis) were collected in each area and from a pool of species for determination of bromatologic composition. In the dry season, only the pool of species and the grass Aristida adscensionis were evaluated. There was a significant effect of the studied area on the chemical composition of all analyzed species. The nutrient content found in the dry matter (DM) and the digestibility of the pool of species indicate that caatinga herbs presented improved quality in the rainy season. The qualitative variables of the studied species were most heterogeneous due to the variability found in caatinga. Conservation conditions in caatinga and season of the year influence bromatologic composition of the species Arachis pintoi, Boerhavia diffusa L., Heliotropium ternatum Vahl. Aristida adscensionis L. and of a pool of typical species found in Caatinga.

Abundance of Callicebus barbarabrownae (Hershkovitz 1990),(Primates: Pitheciidae) and other nonvolant mammals in a fragment of arboreal Caatinga in northeastern Brazil

Abundance of Callicebus barbarabrownae (Hershkovitz 1990),(Primates: Pitheciidae) and other nonvolant mammals in a fragment of arboreal Caatinga in northeastern Brazil

Forced copulation attempt in the Blue-tailed Lizard, Micrablepharus maximiliani (Reinhardt & Luetken, 1862) (Squamata, Gymnophthalmidae) in the Caatinga of Northeastern Brazil

Forced copulation is characterized by jerky and rapid movements performed by a female in an apparent attempt to escape from a mounting male. This short communication reports a forced copulation attempt by the gymnophthalmid lizard Micrablepharus maximiliani in a forest enclave inside the Caatinga biome, Tenente Laurentino Cruz municipality, Rio Grande do Norte, Brazil. The rejection behavior of the female consisted of running, pushing and hiding from the mounting male. Although the causes of female mate rejection remain unclear, it may be possible that on this occasion the female M. maximiliani may not have been reproductively active and/or avoided the male deliberately.

Ventral Colored Patches in Tropidurus semitaeniatus (Squamata, Tropiduridae): Sexual Dimorphism and Association with Reproductive Cycle

We describe sexual dimorphism in coloration and the reproductive cycle in Tropidurus semitaeniatus, a widely distributed lizard species in the caatinga of northeastern Brazil. Yellow and yellow- and-black patches occurred on the ventral surface of the thighs and precloacal flap in 15 and 11 adult males, respectively. Thirteen reproductively active males (collected November to March) had ventral patches with intense pigmentation, contrasting with the faded pigmentation of these patches in two males during the maturation stage (collected in October) and in 11 individuals in regression phase (collected April to September). Thirty-six adult females, reproductively active and not, and 21 juveniles lacked ventral color patches. There was a significant relationship between snout-vent length and testis volume during maturation and regression stages in males with both types of color patches. We conclude that ventral color patches displayed by male T. semitaeniatus are closely associated with their reproductive cycles.

Comportamento fenológico de três espécies de Jatropha (Euphorbiaceae) da Caatinga, semi-árido do Brasil

O comportamento fenologico vegetativo e reprodutivo de Jatropha mollissima (Pohl) Baill., Jatropha mutabilis (Pohl) Baill. e Jatropha ribifolia (Pohl) Baill. foi comparado em uma area de caatinga hiperxerofila arbustiva-arborea do nordeste brasileiro, no periodo de julho de 2005 a junho de 2007. Adicionalmente, investigou-se a correlacao entre as fenofases e as variaveis abioticas (temperatura, umidade relativa, precipitacao e fotoperiodo), a capacidade de armazenamento de agua e o padrao de distribuicao espacial. Todas as especies apresentaram alta capacidade de armazenamento de agua e comportamento fenologico continuo e irregular com ausencia de flores, frutos, queda foliar e brotamento nos meses mais frios e umidos do ano. Apenas a floracao de J. ribifolia apresentou correlacao significativa com a precipitacao. As tres especies apresentaram populacoes com distribuicao agregada, favorecida principalmente devido ao processo de dispersao de sementes por autocoria. Os resultados obtidos indicam que a alta capacidade de armazenamento de agua pelas especies garante a ocorrencia dos eventos fenologicos mesmo na ausencia de chuvas.

Seasonality of insects in the semi-arid Caatinga of northeastern Brazil

Insects are essential to tropical ecosystems functioning. In semi-arid regions, the increase in abundance and/or activity (e.g. reproduction and foraging behavior) of insects is usually associated with climatic variables. The present study investigates which climatic variables are best predictors of insect abundance in an area of Caatinga in northeastern Brazil. Individuals were sampled for 24 months using Malaise and pitfall traps, and beating trays. A total of 58925 individuals belonging to 20 insect orders were collected. The most abundant orders were Hymenoptera, Diptera, Collembola and Coleoptera. Most orders studied showed a clear maximum abundance in the rainy season. Rainfall and humidity were the best predictors of insect abundance in the Caatinga. However, no climatic variable could explain Psocoptera and Blattodea variance in abundance/activity. Our results suggest that climatic changes associated with rainfall patterns in the Caatinga may affect ecosystem processes and services that depend direct or indirectly on insect abundance/activity.

Density of the Near Threatened jaguar Panthera onca in the caatinga of north-eastern Brazil

We report the first estimate of jaguar density in the semi-arid caatinga biome of north-eastern Brazil. During August–October 2007, in the Serra da Capivara National Park, we used camera traps to identify and count jaguars. Jaguar abundance and density were calculated using mark-recapture models. In a sampling effort of 1,249 camera-trap-nights we identified 12 adult jaguars and estimated an abundance of 14 ± SE 3.6 jaguars in an area of 524 km2, i.e. a density of 2.67 ± SE 1.00 jaguars per 100 km2. This estimate is higher than in most other Brazilian biomes and indicates Serra da Capivara National Park as an important reserve for protecting jaguars in north-eastern Brazil.

The effects of seasonality on the foraging behavior of Tropidurus hispidus and Tropidurus semitaeniatus (Squamata: Tropiduridae) living in sympatry in the Caatinga of northeastern Brazil

In this study, we performed field observations of 38 and 84 specimens of the lizards Tropidurus hispidus (Spix, 1825) and Tropidurus semitaeniatus (Spix, 1825), respectively, inhabiting a Caatinga in the state of Rio Grande do Norte, northeastern Brazil, in order to describe the foraging behavior, measure the foraging intensity (number of movements, time spent stationary, distance traveled and number of attacks on preys) and investigate the effects of seasonality on the foraging strategies of these two species of lizards. During the dry season, both species showed no significant differences in foraging intensity. In the wet season, on the other hand, only the distance traveled was similar for both species. Tropidurus semitaeniatus displayed a larger mean number of movements (9.8 ± 1.2) and attacks on preys (1.7 ± 0.3) when compared to T. hispidus (3.0 ± 0.8 moves; 0.3 ± 0.1 attacks). Additionally, mean time spent stationary was significantly longer for T. hispidus (596.6 ± 1.0 seconds) than for T. semitaeniatus (587 ± 2.1 seconds). Results suggest that the low number of movements and short distance traveled (maximum of 1000 cm during 10-minute intervals) are consistent with the categorization of T. hispidus and T. semitaeniatus as sit-and-wait foragers. Given our results, we conclude that both species co-exist under limiting conditions during the dry season, with similar foraging behavior and similar rates of foraging intensity, segregating with respect to these variables in the wet season.

Comunidade de abelhas (Hymenoptera, Apoidea) e plantas em uma área do Agreste pernambucano, Brasil

O Agreste é uma região de transição entre floresta tropical úmida e caatinga no nordeste brasileiro. Nessa região, grande parte da vegetação nativa foi desmatada para a implantação de pastagens. Não é sabido se áreas degradadas mantém uma apifauna e flora melitófila diversificada, ou quais são associações entre abelhas e plantas que ocorrem nessas áreas. A cobertura vegetal atual é composta por pastos, vegetação ruderal e restos da vegetação nativa. Abelhas e plantas por elas visitadas foram coletadas mensalmente entre agosto de 2001 e julho de 2002, durante dois dias consecutivos entre 5h30 e 17h30. Foram coletados 1.004 indivíduos de abelhas pertencentes a 79 espécies. Apidae foi a família mais abundante e com maior riqueza de espécies (732 indivíduos e 43 espécies), seguida por Halictidae (194 indivíduos e 20 spp.), Megachilidae (47 indivíduos e 13 spp.), Colletidae (16 indivíduos e 2 spp.) e Andrenidae (15 indivíduos e 1 sp.). Foram registradas apenas três espécies de abelhas eussocais e cinco de Euglossini, dois grupos altamente diversificados nas florestas neotropicais. A ausência de abelhas sem ferrão nativas dos gêneros Plebeia, Frieseomelitta, Partamona, Scaptotrigona e Trigonisca, assim como de outras espécies de Euglossini, deve estar relacionada à falta de sítios de nidificação e à escassez de fontes de pólen e néctar nessa área degradada. Foram registradas 87 espécies de plantas melitófilas, a maioria ervas e arbustos. Árvores nativas isoladas, assim como plantas ornamentais e frutíferas cultivadas contribuem para manter parte da diversidade da comunidade de abelhas nativas.

Ocorrência de auto-incompatibilidade homomórfica em Mitracarpus longicalyx E. B. Souza & M. F. Sales (Rubiaceae - Spermacoceae)

The breeding system of Mitracarpus longicalyx was studied from September to December 2004 at Feira de Santana, BA, Brazil. This species is an annual herb found in the caatinga of northeastern Brazil, flowering between June and December. The inflorescences are glomerules with ca. 90 flowers. Each flower has a white 4-5 mm long hypocrateriform corolla. The flowers are protandrous with a three days long staminate phase followed by a five days long pistilate phase. No overlapping between phases was observed within a flower, but flowers in different phases appear in the same inflorescence. M. longycalyx is psycophilous species, pollinated by Hemiargus hanno hanno (Stoll, 1790) (Lycaenidae). Hand-pollination tests indicated that M. longicalyx is a self-incompatible, non-agamospermous species, with high fruit set under natural conditions (97.8%) in the studied population; fruit set was also high (82.3%) with hand cross-pollinations but geitonogamous hand pollination gave zero fruit set. Out-crossed pollen tubes reached the ovary within 24h after pollination, while selfed pollen grains failed to germinate or selfed pollen tubes failed to penetrate the stigmatic papillae. The results indicate that M. longicalyx has homomorphic self-incompatibility, possibly of the sporophytic type, in addition to protandry. Homomorphic self-incompatibility is very rare in the Rubiaceae, a family with abundant occurrence of heteromorphic self-incompatibility.

New combinations in Senegalia Raf. (Leguminosae: Mimosoideae)

Acacia Mill. in the traditional sense embraces c. 1,400 species from tropical areas of the World. Phylogenetic studies carried out since the decade of 1990 have shown that the genus is polyphyletic and should be split into five genera. Species native to the Caatinga of Northeastern Brazil belong to the former subgenus Aculeiferum , a group now segregated from Acacia and renamed as Senegalia . In this work, eight new combinations are presented in this genus: Senegalia bahiensis (Benth.) A.Bocage & L.P.Queiroz, Senegalia kallunkiae (J.W.Grimes & Barneby) A.Bocage & L.P.Queiroz, Senegalia langsdorffii (Benth.) A.Bocage & L.P.Queiroz, Senegalia martiusiana (Steud.) A.Bocage & L.P.Queiroz, Senegalia monacantha (Willd.) A.Bocage & L.P.Queiroz, Senegalia piauhiensis (Benth.) A.Bocage & L.P.Queiroz, Senegalia santosii (G.P.Lewis) A.Bocage & L.P.Queiroz and Senegalia velutina (DC.) A.Bocage & L.P.Queiroz.

Changing the Course of Biodiversity Conservation in the Caatinga of Northeastern Brazil

Abstract: The 735,000‐km2 Caatinga is a mosaic of thorn scrub and seasonally dry forests, with more than 2000 species of vascular plants, fishes, reptiles, amphibians, birds, and mammals. Endemism in these groups varies from 7% to 57%. Inappropriate land use has already caused serious environmental damage and accelerating desertification, which is currently threatening about 15% of the region. Moreover, the rich and diversified biota of the Caatinga is poorly protected: only 11 reserves (<1% of the region) are strictly protected areas. A conservation strategy for the Caatinga biota should be designed to (1) avoid further habitat loss and desertification, (2) maintain key ecological services necessary for improving the living standards of the rural population, and (3) promote the sustainable use of the region's natural resources. Implementing an effective conservation agenda for the Caatinga is not an easy task but, with creativity and consistent financial support, it should be possible to nurture this unique biome and guarantee the preservation of its rich and diversified fauna and flora, and, with this, the well‐being of its rural populations.

Ecology of the Gecko Gymnodactylus geckoides amarali in a Neotropical Savanna

We describe the ecology of the gecko Gymnodactylus geckoides amarali in the Cerrado of central Brazil and using published data, compare it with the conspecific Gymnodactylus geckoides geckoides from the Caatinga of northeastern Brazil. Gymnodactylus geckoides amarali is rupicolous, living primarily in rock crevices in “campos rupestres” (rocky fields), which are highly patchy in Cerrado. Field body temperatures were low and associated with environmental temperatures, suggesting thermoconformity. Termites were the most important food item, and consumption was greatest during the dry season. We suggest that access to termites is facilitated by the shallow soils used by G. g. amarali and by its well-developed chemosensory apparatus. Reproduction was concentrated in the dry season, a pattern known for very few Cerrado squamates, possibly because of the higher availability of termites during that period. Clutch size was significantly correlated with female size, a pattern unknown in any other gecko, and there was no association between egg size and female size. Gymnodactylus geckoides amarali produced larger clutches of smaller eggs relative to G. g. geckoides, presumably because of the high climatic unpredictability of the Caatinga. We detected a significant sexual dimorphism in both body size and shape: females were larger and had smaller heads than males. We suggest that large female size is likely a plesiomorphic character of gekkonids and that large head size in males results from sexual selection theory.

Systematics and Biogeography of the Bee Genus Caenonomada Ashmead, 1899 (Hymenoptera: Apidae: Tapinotaspidini)

The species of Caenonomada, a bee genus characteristic of the xeric habitats of eastern South America, are revised. Three species are recognized, including a new one, C. labrata sp. nov., from central Brazil. A lectotype is designated for C. tertia Cockerell, 1912, which is considered a synonym of C. unicalcarata (Ducke, 1908). This species has its main area of occurrence in the semi-arid Caatinga of northeastern Brazil and two isolated records, here interpreted as disjunct populations, in central Brazil and in Tucumán, Argentina. C. bruneri Ashmead, 1899 occurs in northern Argentina, Paraguay, and southern Brazil. Tetrapedia pluricinctaVachal, 1909, previously considered a species of Caenonomada, is transferred to the genus Monoeca Lepeletier & Serville, 1828. An identification key and illustrations are provided. Phylogenetic analysis based on morphological characters of adult specimens supported only one hypothesis of relationship among the species: ((C. bruneri + C. labrata sp. nov.) C. unicalcarata). The resulting area cladogram implies two vicariance events, followed by dispersal of C. unicalcarata from northeastern Brazil to the arid regions of northern Argentina. The historical relationship between the areas, as indicated by the present study, is different from that obtained by other authors who studied forest associated organisms. It is postulated that this divergence is due to the fact that the historical hypotheses refer to different ancestral biotas, one associated with xeric habitats and the other associated with forest habitats.

Reproductive biology ofCaesalpinia calycina andC. pluviosa (Leguminosae) of the caatinga of north-eastern Brazil

The pollination biology, breeding system and fruiting success ofCaesalpinia calycina andC. pluviosa var.sanfranciscana were studied in caatinga vegetation in Bahia, NE Brazil. The principal pollinators for both species were carpenter bees.Caesalpinia calycina is andromonoecious but inC. pluviosa all flowers are hermaphrodite. InC. calycina all selfed flowers were abscised within 72 h despite rapid self-pollen tube growth to the ovary and ovule penetration. Prevention of selfing therefore seems to be controlled by a post-zygotic mechanism. Both species had very low fruit-set and it is suggested that this is at least in part due to geitonogamous pollinations with ovule penetration by self pollen tubes.

The rediscovery ofCallicebus personatus barbarabrownae in northeastern brazil with a new western limit for its distribution

We rediscovered a group of Barbarabrown titis inhabiting the remnants of the gallery forest associated with a system of small temporary lakes and intermittent streams at the Fazenda Conceicao, Miroros (11°24'S, 42°17'W), State of Bahia, northeastern Brazil. This represents a new western limit for the geographic distribution ofCallicebus personatus barbarabrownae and provides an important evidence for the role of gallery forests as mesic corridors allowing elements of the Atlantic Forest fauna to penetrate into the semi-arid caatinga of northeastern Brazil.

Serra da Capivara National Park and the conservation of north-eastern Brazil's caatinga: F. Olmos, Oryx, 26(3), 1992, pp 142–146

Serra da Capivara National Park and the conservation of north-eastern Brazil's caatinga: F. Olmos, Oryx, 26(3), 1992, pp 142–146

Serra Da Capivara National Park and the conservation of north-eastern Brazil's caatinga

Serra da Capivara is the second largest protected area in Brazil's caatinga – a mosaic of dry habitats in the north-east with a diverse flora and fauna, including several threatened and recently discovered taxa. The park is not effectively protected, however, and there is growing pressure from the surrounding human population.