Mechanisms underlying the occurrence of species in complex modified tropical landscapes: a case study of amphibians in the Osa Peninsula, Costa Rica

2018 ◽  
Vol 34 (1) ◽  
pp. 32-40 ◽  
Author(s):  
Tanya J. Hawley Matlaga
Keyword(s):  
Costa Rica ◽  
High Performance ◽  
Breeding Site ◽  
Larval Period ◽  
Forest Habitat ◽  
Offspring Performance ◽  
Osa Peninsula ◽  
Size At Metamorphosis ◽  
Site Use ◽  
Tropical Landscapes

Abstract:The mechanisms underlying occupancy patterns of species in modified tropical landscapes are poorly understood. The presence of adults in a modified habitat may not necessarily indicate the quality of the habitat for sub-adult stages. These issues were addressed by examining patterns in breeding-site use by adult frogs and tadpole performance across a pasture-forest gradient in the Osa Peninsula, Costa Rica. The use of artificial pools by adult frogs for breeding activity was quantified along three transects, with a pool located at the edge (0 m) and 10, 30 and 50 m into forest and pasture. Next, survival, size at metamorphosis and time to metamorphosis were quantified for tadpoles of Engyptomops pustulosus and Dendrobates auratus in artificial pools at the edge, pasture and forest. Adult frogs used breeding pools non-randomly; two species used pools only in pasture, whereas three species used pools only in forest. In addition, Smilisca phaeota used pools in pasture and at the edge while E. pustulosus used pools across the pasture-forest gradient. The habitat where adults used breeding pools generally also yielded high performance of their tadpoles, with some exceptions. Tadpole survival to metamorphosis was low in pastures (<5%) and higher in edge and forest (>18%) for D. auratus; in contrast, survival of E. pustulosus was over 80% in each habitat. Metamorphs of D. auratus were largest in edges but larval period did not differ among habitats. Metamorphs of E. pustulosus were 18% larger and larval period was 27% shorter in pastures compared with forest. These results suggest that modified habitats represent an ecological jackpot for some species, such that offspring performance is enhanced compared with that in forest habitat. Populations of other species may be restricted to forest habitat because of intolerable abiotic conditions in modified habitats. The results of this study indicate that adult breeding site use and tadpole performance contribute to mechanisms that underlie patterns of species occupancy in modified tropical landscapes.

Osa Peninsula, Costa Rica: A unique opportunity to drill and instrument the seismogenic zone of large megathrust earthquakes

2019 ◽  
Author(s):  
Marino Protti ◽  
◽  
Nathan Bangs ◽  
Peter Baumgartner ◽  
Donald Fisher ◽  
...  
Keyword(s):  
Costa Rica ◽  
Seismogenic Zone ◽  
Osa Peninsula ◽  
Megathrust Earthquakes

New species of Calathea (Marantaceae) endemic to Costa Rica

1997 ◽  
Vol 75 (8) ◽  
pp. 1356-1362 ◽  
Author(s):  
Helen Kennedy
Keyword(s):  
New Species ◽  
Costa Rica ◽  
Key Words ◽  
Osa Peninsula ◽  
The Pacific ◽  
Pacific Slope ◽  
Cordillera De Talamanca

Calathea hylaeanthoides Kennedy, Calathea retroflexa Kennedy, and Calathea incompta Kennedy are described as new. All three species are endemic to Costa Rica. Calathea hylaeanthoides and C. incompta are from the Osa Peninsula, while C. retroflexa is from midelevation on the Pacific slope of the Cordillera de Talamanca. Calathea hylaeanthoides belongs to Calathea section Breviscapus, C. retroflexa belongs to Calathea section Calathea, and C. incompta belongs to the "Ornata group" of Calathea. Key words: Marantaceae, Calathea, Costa Rica, endemism.

Phytogeography of the trees of the Osa Peninsula, Costa Rica

Brittonia ◽  
2012 ◽  
Vol 64 (1) ◽  
pp. 76-101 ◽  
Author(s):  
Xavier Cornejo ◽  
Scott A. Mori ◽  
Reinaldo Aguilar ◽  
Hannah Stevens ◽  
Francine Douwes
Keyword(s):  
Costa Rica ◽  
Osa Peninsula

Ecotourism: the ‘human shield’ for wildlife conservation in the Osa Peninsula, Costa Rica

2019 ◽  
Vol 19 (3) ◽  
pp. 197-216 ◽  
Author(s):  
Beatriz Lopez Gutierrez ◽  
A. M. Almeyda Zambrano ◽  
G. Mulder ◽  
C. Ols ◽  
R. Dirzo ◽  
...  
Keyword(s):  
Costa Rica ◽  
Wildlife Conservation ◽  
Osa Peninsula ◽  
Human Shield

Size and Age at Metamorphosis in Marine Fishes: An Analysis of Laboratory-Reared Winter Flounder (Pseudopleutonectes americanus) with a Review of Variation in Other Species

1987 ◽  
Vol 44 (11) ◽  
pp. 1936-1947 ◽  
Author(s):  
R. Christopher Chambers ◽  
William C. Leggett
Keyword(s):  
Larval Period ◽  
Marine Fishes ◽  
Winter Flounder ◽  
Pseudopleuronectes Americanus ◽  
Competitive Effects ◽  
Pooled Data ◽  
Risk Of Predation ◽  
Size At Metamorphosis ◽  
Developmental Rates ◽  
Positive Correlations

Offspring of adult winter flounder (Pseudopleuronectes americanus) collected from Conception Bay, Newfoundland, were reared from fertilization to metamorphosis. We tested two hypotheses: 1) length and age at metamorphosis are equally variable among individuals and (2) length and age at metamorphosis are not correlated. Length at metamorphosis was significantly less variable than age at metamorphosis when data from all laboratory populations were pooled and in 15 of 18 populations. Coefficients of variation for length and age at metamorphosis for the pooled data were 0.051 and 0.123, respectively. Length and age at metamorphosis were positively correlated when the data were pooled (r = 0.42, p < 0.001) and within 8 of 18 populations. Larvae that metamorphose late do so at larger sizes. When length and age at metamorphosis were converted to growth and developmental rates for the full larval period, significant positive correlations were evident between these rates for the pooled data (r = 0.68, p < 0.001) and within 16 of 18 populations. Larvae that grow slowly, therefore, remain as larvae longer. An examination of published values on size and age at metamorphosis in marine fishes revealed a pattern consistent with our findings both within and among populations and environments: (1) variation in length was less than variation in age at metamorphosis and (2) positive correlations between growth and developmental rates were evident through the larval period. Increased size at metamorphosis may ameliorate competitive effects and reduce the risk of predation in the period immediately following metamorphosis. Due to the considerable variation in the duration of the larval period (age at metamorphosis) the number of individuals that successfully metamorphose and subsequently enter the mature population could be significantly altered under differing environmental conditions.

Influence of desiccation, predatory cues, and density on metamorphic traits of the bronze frog Hylarana temporalis

2016 ◽  
Vol 37 (2) ◽  
pp. 199-205 ◽  
Author(s):  
Santosh Mogali ◽  
Srinivas Saidapur ◽  
Bhagyashri Shanbhag
Keyword(s):  
Ecological Factors ◽  
Larval Period ◽  
Ecological Factor ◽  
Water Quantity ◽  
Predation Threat ◽  
Predator Pressure ◽  
Size At Metamorphosis ◽  
The Cost ◽  
Pantala Flavescens

We conducted an experiment to understand the influence of ecological factors (desiccation, predation threat and density) on two major metamorphic traits, larval period and size at metamorphosis, in the Indian bronze frog,Hylarana temporalis. Tadpoles were reared in groups of 15 (low), 30 (medium) and 60 (high) densities. We created the threat of desiccation by removing 0.5 l water at 10 days intervals until the water quantity reached 0.5 l. Caged dragonfly larvae (Pantala flavescens) provided the predation threat. Results show that each ecological factor independently influenced metamorphic traits but not in an interactive way. Under desiccation threat the tadpoles metamorphosed earlier and at smaller sizes compared to those reared in constant water (at corresponding densities) regardless of presence/absence of predator. In contrast, under predation threat, tadpoles metamorphosed early and at a bigger size than those reared without predator regardless of density of rearing, and desiccation threat. Alternatively, an increase in density of rearing delayed metamorphosis with smaller metamorphic size in constant water and also under threat of desiccation regardless of whether predation threat existed or not. Thus, our study revealed thatH. temporalistadpoles can modify their response to each ecological factor regardless of what other factors operate simultaneously; the threat of desiccation shortens larval period at the cost of growth. Whereas, predator pressure shortens larval period along with increased growth; while greater density increases larval period and slows down growth inH. temporalis.

The evolution of adult body size in black-bellied salamanders (Desmognathus quadramaculatus complex)

2000 ◽  
Vol 78 (10) ◽  
pp. 1712-1722 ◽  
Author(s):  
Carlos D Camp ◽  
Jeremy L Marshall ◽  
Richard M Austin, Jr.
Keyword(s):  
Growth Rate ◽  
Body Size ◽  
Larval Growth ◽  
Larval Period ◽  
Moisture Level ◽  
Adult Body Size ◽  
Larval Growth Rate ◽  
Size At Metamorphosis ◽  
Adult Body ◽  
Desmognathus Quadramaculatus

We investigated the possible role of environmental variables in determining body size within a complex of salamander species (Desmognathus quadramaculatus). We analyzed data generated from life-history studies on populations from throughout the range of this species complex. We incorporated an alternative-hypothesis framework (sensu Platt) to determine the better predictor of adult body size, age at maturity, or size at metamorphosis. We found that almost 90% of the variation in adult body size was explained by size at metamorphosis, which was determined by a combination of rate of larval growth and length of the larval period. Environmental temperature and moisture level were positively correlated with larval growth rate and length of the larval period, respectively. We propose a simple model of body-size evolution that incorporates both adaptive and plastic components. We suggest that the length of the larval period may adaptively respond to moisture-level predictability. In addition, we suggest that the response of the larval growth rate to temperature may be plastic. Because the selection pressure due to drying-induced mortality is pervasive among species of amphibians, it may have played a role in shaping body-size radiation in desmognathines as well as the ecological structure of Appalachian streamside communities.

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