Seasonal use of waterholes and pathways by macrofauna in the dry forest of Costa Rica

2019 ◽  
Vol 35 (2) ◽  
pp. 68-73 ◽  
Author(s):  
Victor H. Montalvo ◽  
Carolina Sáenz-Bolaños ◽  
Luis D. Alfaro ◽  
Juan C. Cruz ◽  
Flavio H. Guimarães-Rodrigues ◽  
...  

AbstractTemporal and spatial scarcity of water in semi-arid and seasonal ecosystems often leads to changes in movements and behaviour of large vertebrates, and in the neotropics this dynamic is poorly understood due to logistical and methodological limitations. Here we used camera trapping to elucidate variation in patterns of seasonal use of waterholes and pathways by 10 large-mammal and four large-bird species in the dry forest of north-western Costa Rica. From 2011 to 2015, we deployed trail cameras at 50 locations, including waterholes and three types of pathway (roads, human trails and animal paths). We used Generalized Linear Models to evaluate the effect of location and seasonality on the rates at which independent photographs were taken. We found interacting effects of location and seasonality for the capuchin monkey (Cebus capucinus), the tiger heron (Trigrisoma mexicanum), the white-tailed deer (Odocoileus virginianus) and the tapir (Tapirus bairdii) suggesting that these species were the most influenced by waterholes during the dry season. Comparison of waterhole sites and specific types of pathways (roads, animal paths and human trails) showed that location influenced photo-capture rates of almost all species, suggesting a useful insight to avoid and account for bias in camera trap studies. Furthering our ecological understanding of seasonal water regimes and large vertebrates’ behaviours allow for better understanding of the consequences of climate change on them.

2017 ◽  
Vol 9 (2) ◽  
Author(s):  
Roberto Vargas-Masis ◽  
Lilliana Piedra-Castro ◽  
Juan Bravo-Chacón

Wetlands maintain high biodiversity and provide important habitat for many bird species, but now have strong pressure from anthropogenic activities. Birds in wetlands are important indicators of environmental changes and our goal was to characterize the bird community in the wetlands Palustrine Corral de Piedra as a mechanism for conservation of tropical dry forest of Costa Rica. We used point counts to describe bird richness and abundance in open (lakes and flooded grasslands) and wooded areas. We described habitat use and microhabitats, trophic guilds, biogeographic distribution and status in Costa Rica. We recorded 83 species of resident birds belonging to 36 families, of which 65 are resident species and 18 have some migratory status in Costa Rica. Secondary consumer species of small vertebrates corresponded to 45,8% and primary consumers were 25,3%. The birds mainly used trees for perching but use emergent shrubs, floating vegetation and water. We found a large number of Egrets, Flycatchers and Hawks playing important roles as pollinators, seed dispersers and predator is adding significant value to the ecological dynamics of forests and lakes in the area. Corral de Piedra has special importance as a site for the establishment of migratory birds and large number of resident species of conservation concern. We consider that joint efforts between residents and researchers are an important tool for bird conservation in the region.


2004 ◽  
Vol 155 (3-4) ◽  
pp. 80-88 ◽  
Author(s):  
Klaus Ackermann

Wild growing yams (Dioscorea spp.) are an important supplementary food in Madagascar, especially during periods of rice shortage in the rainy season. Yams grow in dry forests and there is a particularly high occurrence of yam tubers in recently burned, open secondary forest formations. The study found that the uncontrolled harvest of yams can contribute to the degradation of dry forests due to the high quantity of wild yams harvested by the local population and the widespread practice of intentionally burning forests to increase yams production.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
David Gagnon ◽  
Abderrahim Zeribi ◽  
Élise Douard ◽  
Valérie Courchesne ◽  
Borja Rodríguez-Herreros ◽  
...  

Abstract Background Language delay is one of the major referral criteria for an autism evaluation. Once an autism spectrum diagnosis is established, the language prognosis is among the main parental concerns. Early language regression (ELR) is observed by 10–50% of parents but its relevance to late language level and socio-communicative ability is uncertain. This study aimed to establish the predictive value of ELR on the progression of language development and socio-communicative outcomes to guide clinicians in addressing parents’ concerns at the time of diagnosis. Methods We used socio-communicative, language, and cognitive data of 2,047 autism spectrum participants from the Simons Simplex Collection, aged 4–18 years (mean = 9 years; SD = 3.6). Cox proportional hazard and logistic regression models were used to evaluate the effect of ELR on language milestones and the probability of using complex and flexible language, as defined by the choice of ADOS module at enrollment. Linear models were then used to evaluate the relationship of ELR and non-verbal IQ with socio-communicative and language levels. Results ELR is associated with earlier language milestones but delayed attainment of fluent, complex, and flexible language. However, this language outcome can be expected for almost all autistic children without intellectual disability at 18 years of age. It is mostly influenced by non-verbal IQ, not ELR. The language and socio-communicative level of participants with flexible language, as measured by the Vineland and ADOS socio-communicative subscales, was not affected by ELR. Limitations This study is based on a relatively coarse measure of ultimate language level and relies on retrospective reporting of early language milestones and ELR. It does not prospectively document the age at which language catches up, the relationship between ELR and other behavioral areas of regression, nor the effects of intervention. Conclusions For autistic individuals with ELR and a normal level of non-verbal intelligence, language development follows a “bayonet shape” trajectory: early first words followed by regression, a plateau with limited progress, and then language catch up.


2006 ◽  
Vol 53 (6) ◽  
pp. 522-530 ◽  
Author(s):  
LINDA A. AMARAL-ZETTLER ◽  
JEFFREY COLE ◽  
ABBY D. LAATSCH ◽  
THOMAS A. NERAD ◽  
O. ROGER ANDERSON ◽  
...  

2002 ◽  
Vol 62 (2) ◽  
pp. 339-346 ◽  
Author(s):  
J. RAGUSA-NETTO

Figs are a remarkable food resource to frugivores, mainly in periods of general fruit scarcity. Ficus calyptroceras Miq. (Moraceae) is the only fig species in a type of dry forest in western Brazil. In this study I examined the fruiting pattern as well as fig consumption by birds in F. calyptroceras. Although rainfall was highly seasonal, fruiting was aseasonal, since the monthly proportion of fruiting trees ranged from 4% to 14% (N = 50 trees). I recorded 22 bird species feeding on figs. In the wet season 20 bird species ate figs, while in the dry season 13 did. Parrots were the most important consumers. This group removed 72% and 40% of the figs consumed in the wet and dry seasons, respectively. No bird species increases fig consumption from dry to wet season. However, a group of bird species assumed as seed dispersers largely increases fig consumption from wet to dry season, suggesting the importance of this resource in the period of fruit scarcity. The results of this study points out the remarkable role that F. calyptroceras plays to frugivorous birds, in such a dry forest, since its fruits were widely consumed and were available all year round.


Ecohydrology ◽  
2015 ◽  
Vol 9 (4) ◽  
pp. 659-672 ◽  
Author(s):  
Suzanne M. de Szoeke ◽  
Thomas L. Crisman ◽  
Paul E. Thurman

2012 ◽  
Vol 21 (1) ◽  
pp. 7-15 ◽  
Author(s):  
Fabiane Sebaio ◽  
Érika Martins Braga ◽  
Felipe Branquinho ◽  
Alan Fecchio ◽  
Miguel Ângelo Marini

Parasites may lead bird species to extinction, affect host temporal and spatial population dynamics, alter community structure and alter individuals’ social status. We evaluated blood parasite prevalence and intensity according to bird families and species, among 925 birds that were caught in 2000 and 2001, in the Atlantic Forest in the State of Minas Gerais, Brazil. We applied Giemsa staining to thin blood smears, to detect blood parasites. The birds (n = 15.8%) in 11 families, were infected by at least one parasite genus, especially Muscicapidae (28.3%) and Conopophagidae (25%). Among the 146 infected birds, Plasmodium was detected in all bird families and had the highest prevalence (54.8%). Trypanosoma, Haemoproteus and microfilaria had lower prevalence rates (23.3, 23.3 and 2.1%, respectively). Birds caught during the rainy season were more infected than birds caught during the dry season. The overall low prevalence of blood parasites in birds is similar to the patterns found elsewhere in the Neotropical region.


Forests ◽  
2020 ◽  
Vol 11 (12) ◽  
pp. 1241
Author(s):  
Hernán Morffi-Mestre ◽  
Gregorio Ángeles-Pérez ◽  
Jennifer S. Powers ◽  
José Luis Andrade ◽  
Astrid Helena Huechacona Ruiz ◽  
...  

Litterfall production plays a fundamental role in the dynamics and function of tropical forest ecosystems, as it supplies 70–80% of nutrients entering the soil. This process varies annually and seasonally, depending on multiple environmental factors. However, few studies spanning several years have addressed the combined effect of climate variables, successional age, topography, and vegetation structure in tropical dry forests. In this study, we evaluated monthly, seasonal, and annual litterfall production over a five-year period in semideciduous dry forests of different successional ages growing on contrasting topographic conditions (sloping or flat terrain) in Yucatan, Mexico. Its relationship with climate and vegetation structural variables were also analyzed using multiple linear regression and generalized linear models. Litterfall was measured monthly in 12 litterfall traps of 0.5 m2 in three sampling clusters (sets of four 400 m2 sampling plots) established in forests of five successional age classes, 3–5, 10–17, 18–25, 60–79, and >80 years (in the latter two classes either on slopping or on flat terrain), for a total of 15 sampling clusters and 180 litterfall traps. Litterfall production varied between years (negatively correlated with precipitation), seasons (positively correlated with wind speed and maximum temperature), and months (negatively correlated with relative humidity) and was higher in flat than in sloping sites. Litterfall production also increased with successional age until 18–25 years after abandonment, when it attained values similar to those of mature forests. It was positively correlated with the aboveground biomass of deciduous species but negatively correlated with the basal area of evergreen species. Our results show a rapid recovery of litterfall production with successional age of these forests, which may increase with climate changes such as less precipitation, higher temperatures, and higher incidence of hurricanes.


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