Temporal Variation in Point Counts of Birds in a Lowland Wet Forest in Costa Rica

ABSTRACT(1) During 1978–1981, marked individuals of 107 species of treelets and shrubs in three forest types between 1300–1650 m elevation at Monteverde, Costa Rica, were monitored at monthly intervals for behaviour of leafing, flowering, and fruiting.(2) Although there was not a pronounced seasonal pattern of leafing activity, more species produced new leaves in the dry season. Species that flush large quantities of new leaves do so more commonly in the drier months. Leaf loss was gradual and unobtrusive in species observed.(3) Flowering activity was greatest in the late dry season and early wet season. Most species exhibited extended flowering; only 15% of the species were massively flowering. Massive flowerers showed less seasonality than extended flowerers.(4) Of the species studied, the majority had relatively unspecialized flowers which were visited by a variety of insects; small bee-pollination was the next most common, followed by hummingbird, beetle, settling moth, sphingid, butterfly, large bee and fly pollination (the pollination system of 18 species was unknown). Hummingbird pollinated species showed little seasonality of flowering when compared with species exhibiting small moth, and beetle pollination syndromes, as well as those with unspecialized flowers.(5) The vast majority of species studied have fleshy fruits (sarcochores). Fruiting activity was less markedly seasonal than flowering. Species with fruit are more numerous in the second half of the year (the wet season and early dry season). The second year of the study saw substantially fewer species in fruit than the first year; this is attributed to the greater than usual rainfall and inclement weather during the peak flowering season.(6) Cloud forest shrub and treelet phenology is compared with patterns of other forests that have been studied. In general, the greater the rainfall, the less seasonality of flowering and fruiting is seen. Although Monteverde is very wet, rainfall is intermediate between that of lowland dry and lowland wet forest in Costa Rica. Seasonality of flowering and fruiting at Monteverde is more pronounced than at La Selva (wet) and less obvious than in Guanacaste (dry).

Download Full-text

The influence of tree species on canopy soil nutrient status in a tropical lowland wet forest in Costa Rica

Plant and Soil ◽

10.1007/s11104-008-9816-9 ◽

2008 ◽

Vol 318 (1-2) ◽

pp. 47-61 ◽

Cited By ~ 40

Author(s):

Catherine L. Cardelús ◽

Michelle C. Mack ◽

Carrie Woods ◽

Jennie DeMarco ◽

Kathleen K. Treseder

Keyword(s):

Costa Rica ◽

Tree Species ◽

Soil Nutrient ◽

Nutrient Status ◽

Soil Nutrient Status ◽

Tropical Lowland ◽

Canopy Soil ◽

Lowland Wet Forest

Download Full-text

Temporal variation of mineralogy and petrology in cognate gabbroic enclaves at Arenal volcano, Costa Rica

Contributions to Mineralogy and Petrology ◽

10.1007/bf00371368 ◽

1989 ◽

Vol 103 (1) ◽

pp. 110-122 ◽

Cited By ~ 48

Author(s):

James S. Beard ◽

Andrea Borgia

Keyword(s):

Costa Rica ◽

Temporal Variation ◽

Arenal Volcano

Download Full-text

Temporal Variation in Infection Prevalence by the Amphibian Chytrid Fungus in Three Species of Frogs at La Selva, Costa Rica

Biotropica ◽

10.1111/j.1744-7429.2012.00872.x ◽

2012 ◽

Vol 44 (6) ◽

pp. 779-784 ◽

Cited By ~ 45

Author(s):

Steven M. Whitfield ◽

Jacob Kerby ◽

Lydia R. Gentry ◽

Maureen A. Donnelly

Keyword(s):

Costa Rica ◽

Temporal Variation ◽

Infection Prevalence ◽

Chytrid Fungus ◽

La Selva ◽

Amphibian Chytrid Fungus

Download Full-text

Bird Assemblages in Second-Growth and Old-Growth Forests, Costa Rica: Perspectives From Mist Nets and Point Counts

The Auk ◽

10.1093/auk/118.2.304 ◽

2001 ◽

Vol 118 (2) ◽

pp. 304-326 ◽

Cited By ~ 16

Author(s):

John G. Blake ◽

Bette A. Loiselle

Keyword(s):

Costa Rica ◽

Community Composition ◽

Threatened Species ◽

Bird Species ◽

Old Growth ◽

La Selva ◽

Point Counts ◽

Old Growth Forest ◽

Second Growth ◽

Old Growth Forests

Abstract Second growth has replaced lowland forest in many parts of the Neotropics, providing valuable habitat for many resident and migrant bird species. Given the prevalence of such habitats and the potential benefit for conservation of biodiversity, it is important to understand patterns of diversity in second growth and old growth. Descriptions of species-distribution patterns may depend, however, on method(s) used to sample birds. We used data from mist nets and point counts to (1) describe species diversity and community composition in second-growth (young and old) and old-growth forests at La Selva Biological Station, Costa Rica; and (2) to evaluate perspectives on community composition provided by the two methods. We recorded 249 species from 39 families, including 196 species captured in mist nets (10,019 captures) and 215 recorded during point counts (15,577 observations), which represents ∼78% of the terrestrial avifauna known from La Selva (excluding accidentals and birds characteristic of aquatic or aerial habitats). There were 32 threatened species, 22 elevational migrants, and 40 latitudinal migrants. Species richness (based on rarefaction analyses of capture and count data) was greatest in the youngest site. Latitudinal migrants were particularly common in second growth; elevational migrants were present in both young and old forest, but were more important in old-growth forest. Several threatened species common in second growth were not found in old-growth forests. Trophic composition varied less among sites than did species composition. Mist nets and point counts differed in numbers and types of species detected. Counts detected more species than nets in old-growth forest, but not in young second growth. Mist nets detected 62% of the terrestrial avifauna, and point counts detected 68%. Fifty-three species were observed but not captured, and 34 species were captured but not observed. Six families were not represented by mist-net captures. Data from mist nets and point counts both support the conclusion that second-growth vegetation provides habitat for many species.

Download Full-text

Spatial and Temporal Variation of Seed Rain in a Tropical Lowland Wet Forest

Biotropica ◽

10.2307/2388773 ◽

1996 ◽

Vol 28 (1) ◽

pp. 82 ◽

Cited By ~ 43

Author(s):

Bette A. Loiselle ◽

Eric Ribbens ◽

Orlando Vargas

Keyword(s):

Temporal Variation ◽

Seed Rain ◽

Spatial And Temporal Variation ◽

Tropical Lowland ◽

Lowland Wet Forest

Download Full-text

Diversity of Birds Along an Elevational Gradient in The Cordillera Central, Costa Rica

The Auk ◽

10.1093/auk/117.3.663 ◽

2000 ◽

Vol 117 (3) ◽

pp. 663-686 ◽

Cited By ~ 14

Author(s):

John G. Blake ◽

Bette A. Loiselle

Keyword(s):

Costa Rica ◽

Threatened Species ◽

Rain Forest ◽

Elevational Gradient ◽

Elevational Gradients ◽

Cordillera Central ◽

Montane Rain Forest ◽

Point Counts ◽

Tropical Wet Forest ◽

Valuable Complement

Abstract Species diversity and community composition of birds change rapidly along elevational gradients in Costa Rica. Such changes are of interest ecologically and illustrate the value of protecting continuous gradients of forest. We used mist nets and point counts to sample birds along an elevational gradient on the northeastern Caribbean slope of the Cordillera Central in Costa Rica. Sites included mature tropical wet forest (50 m); tropical wet, cool transition forest (500 m); tropical premontane rain forest (1,000 m); and tropical lower montane rain forest (1,500 and 2,000 m). We recorded 261 species from 40 families, including 168 species captured in mist nets (7,312 captures) and 226 detected during point counts (17,071 observations). The sample included 40 threatened species, 56 elevational migrants, and 22 latitudinal migrants. Species richness (based on rarefaction analyses) changed little from 50 to 1,000 m but was lower at 1,500 and 2,000 m. Mist nets and point counts often provided similar views of community structure among sites based on relative importance of difference categories of species (e.g. migrant status, trophic status). Nonetheless, important differences existed in numbers and types of species represented by the two methods. Ninety-three species were detected on point counts only and 35 were captured only. Ten families, including ecologically important ones such as Psittacidae and Cotingidae, were not represented by captures. Elevational migrants and threatened species occurred throughout the gradient, illustrating the need to protect forest at all elevations. A comparable study from the Cordillera de Tilarán (Young et al. 1998) demonstrated similar patterns of species change along an elevational gradient. Comparisons with that study illustrated that point counts are a valuable complement to mist-net studies. Both studies indicated the diverse nature of the avifauna along elevational gradients in Costa Rica.

Download Full-text