scholarly journals Altitudinal movements and conservation of Bare-necked Umbrellabird Cephalopterus glabricollis of the Tilarán Mountains, Costa Rica

2003 ◽  
Vol 13 (1) ◽  
pp. 45-58 ◽  
Author(s):  
Johel Chaves-Campos ◽  
J. Edgardo Arévalo ◽  
Mariamalia Araya
Keyword(s):  
Costa Rica ◽  
Breeding Season ◽  
Protected Area ◽  
Radio Telemetry ◽  
Fruit Breeding ◽  
Potential Threat ◽  
Fruit Abundance ◽  
Transect Counts ◽  
Using Data ◽  
High Elevations

Bare-necked Umbrellabird Cephalopterus glabricollis is endemic to Costa Rica and western Panama. It eats fruit, breeding at high elevations (≥ 800 m) and migrating to lower elevations during the non-breeding season. Using data from transect counts and radio-telemetry, we monitored bird movements in a protected area (Monteverde–Arenal–San Ramón reserves) in the Tilarán Mountains, Costa Rica. We also monitored fruit abundance along an altitudinal gradient to explore the potential relationship between bird movements and the abundance of the fruits this species consumed. The presence and abundance of umbrellabirds at high elevations (1,400 m) during the breeding season (March–June) coincided with the highest peak of fruit abundance. The presence of umbrellabirds in the lowlands (400 m) during the non-breeding season overlapped with the period of highest fruit abundance at these elevations. At middle elevations, bird presence and abundance did not correlate with fruit abundance. Radio-tagged birds left the protected area during the non-breeding season and there were no umbrellabirds inside the protected area during this period. Habitats where this species bred were well represented in the protected area but the habitat where they spent the non-breeding season was poorly represented, and was not adequately protected. This represents a potential threat to this species in the Tilarán Mountains.

Space fit for a king: spatial ecology of king cobras (Ophiophagus hannah) in Sakaerat Biosphere Reserve, Northeastern Thailand

2019 ◽  
Vol 40 (2) ◽  
pp. 163-178 ◽  
Author(s):  
Benjamin Michael Marshall ◽  
Colin Thomas Strine ◽  
Max Dolton Jones ◽  
Taksin Artchawakom ◽  
Ines Silva ◽  
...  
Keyword(s):  
Habitat Use ◽  
Breeding Season ◽  
Protected Area ◽  
Spatial Ecology ◽  
Radio Telemetry ◽  
Biosphere Reserve ◽  
Adult Males ◽  
Anthropogenic Pressures ◽  
Anthropogenic Landscapes ◽  
Ophiophagus Hannah

Abstract A species’ spatial ecology has direct implications for that species’ conservation. Far-ranging species may be more difficult to conserve because their movements increase their chances of encountering humans. The movements can take them out of protected areas, which is especially risky for species that are routinely persecuted. The king cobra (Ophiophagus hannah), a large venomous elapid, is subject to anthropogenic pressures, such as persecution and habitat loss. Here we present results from a study using radio telemetry to quantify movements and habitat use of nine king cobras in and around a protected area in Northeast Thailand. This study is the first investigation into the movements and habitat use of king cobras outside of the Western Ghats, India. On average, the tracked king cobra’s use areas of 493.42 ± 335.60 ha (95% fixed kernel), moving 183.24 ± 82.63 m per day. King cobras did not remain in intact forested area. Five of the individuals frequently used the human-dominated agricultural areas surrounding the protected area, appearing to make regular use of irrigation canals. Two adult males showed increases in movements during the breeding season. One male’s increased breeding season range caused him to venture beyond the protected area, shifting his habitat use from intact forests to scrub in human-dominated areas. King cobras’ large home range and willingness to use anthropogenic landscapes merits special consideration from conservation planners.

scholarly journals Techniques for Investigating Breeding Chronology in Marbled Murrelets, Desolation Sound, British Columbia

The Condor ◽  
2002 ◽  
Vol 104 (2) ◽  
pp. 319-330 ◽  
Author(s):  
Cecilia Lougheed ◽  
Brett A. Vanderkist ◽  
Lynn W. Lougheed ◽  
Fred Cooke
Keyword(s):  
British Columbia ◽  
Breeding Season ◽  
Radio Telemetry ◽  
Feeding Habits ◽  
Brachyramphus Marmoratus ◽  
Marbled Murrelet ◽  
Breeding Synchrony ◽  
Physiological Analysis ◽  
Using Data ◽  
Marbled Murrelets

AbstractWe used several methods to study the chronology and synchrony of breeding events of the Marbled Murrelet (Brachyramphus marmoratus) population at Desolation Sound, British Columbia, from 1996 to 1998. The timing of breeding events varied among years; on average the breeding season lasted from 21 April to 5 September. We assessed the biases of each method used by comparing the results to the estimate of the integrated breeding chronology. Counts of hatch-year birds at sea were biased toward earlier breeders, missing an estimated 24% of the fledglings. Two other methods, physiological analysis of the yolk precursor vitellogenin from blood samples and monitoring by radio-telemetry could produce a complete distribution of breeding events if sampling were done throughout laying. Observations in the forest, date of first observation of a fledgling at sea during the breeding season, and fish-holding behavior produced insufficient data to be used as sole indicators of breeding chronology of this species. In general, breeding synchrony in alcids, assessed using data from a literature review, was unrelated to feeding habits but increased with latitude (41% of the variation was explained by latitude). Marbled Murrelets, however, bred less synchronously than predicted for an alcid at this latitude (50°N).Técnicas para Investigar la Cronología Reproductiva de Brachyramphus marmoratus en Caleta Desolación, Columbia BritánicaResumen. Utilizamos varios métodos para investigar la cronología reproductiva de la población de Brachyramphus marmoratus en la Caleta Desolación de la Columbia Británica desde 1996 a 1998. Encontramos variaciones temporales en la época reproductiva entre años. En promedio, la estación reproductiva se extendió del 21 de abril al 5 de septiembre. Evaluamos el sesgo de los métodos utilizados comparando los resultados individuales con los resultados de la cronología obtenida al integrar todos los métodos. Los conteos de juveniles en el mar estuvieron sesgados hacia aquellas aves que anidan temprano, no detectando aproximadamente 24% de los juveniles producidos en la estación reproductiva. Los otros dos métodos, análisis fisiológico de muestras de sangre para detectar el precursor de vitelogenina en la yema y monitoreo por telemetría, podrían producir una distribución completa de las etapas reproductivas siempre que el muestreo se lleve a cabo a lo largo de todo el período de puesta. Las observaciones directas en los sitios de anidación, la fecha de la primera observación de juveniles en el mar y las observaciones de aves con pescado en el pico produjeron datos insuficientes para ser considerados indicadores únicos de la cronología reproductiva para esta especie. Con base en una revisión bibliográfica se investigó la sincronía reproductiva en álcidos, encontrándose que ésta no está relacionada con hábitos alimenticios pero que aumenta con la latitud (41% de la variación fue explicada por cambios latitudinales). Sin embargo, B. marmoratus se reprodujo menos sincrónico que lo predicho para un álcido a esta latitud (50°N).

scholarly journals Are tropical reptiles really declining? A six-year survey of snakes in Drake Bay, Costa Rica, and the role of temperature, rain and light

2019 ◽  
Author(s):  
Jose Pablo Barquero-González ◽  
Tracie L. Stice ◽  
Gianfranco Gómez ◽  
Julián Monge-Nájera
Keyword(s):  
Costa Rica ◽  
Environmental Factors ◽  
Sea Level ◽  
Tropical Rainforest ◽  
Transect Counts ◽  
Diet Type

AbstractIntroductionstudies in the last two decades have found declining snake populations in both temperate and tropical sites, including informal reports from Drake Bay, Costa Rica.Objectiveto investigate if reports of decreasing snake populations in Drake Bay had a real basis, and if environmental factors, particularly temperature, rain and light, have played a role in that decrease.Methodswe worked at Drake Bay from 2012 through 2017 and made over 4000 h of transect counts. Using head flashlights we surveyed a transect covered by lowland tropical rainforest at an altitude of 12–38 m above sea level, near the Agujas River, mostly at 1930–2200 hours. We counted all the snakes that we could see along the transect.Resultssnake counts increase from August to September and then decline rapidly. The May snakes/rainfall peaks coincide, but the second snake peak occurs one month before the rain peak; we counted more snakes in dry nights, with the exception of Imantodes cenchoa which was equally common despite rain conditions. We saw less Leptodeira septentrionalis on bright nights, but all other species were unaffected. Along the six years, the number of species with each diet type remained relatively constant, but the number of individuals declined sharply for those that feed on amphibians and reptiles. We report Rhadinella godmani, a highland species, at 12–38 m of altitude.Conclusionnight field counts of snakes in Drake Bay, Costa Rica, show a strong decline from 2012 through 2017.

scholarly journals Novedades en Pteris L. (Pteridaceae) para Costa Rica.

2018 ◽  
Vol 42 ◽  
pp. 165
Author(s):  
Alexander Francisco Rojas Alvarado
Keyword(s):  
New Species ◽  
Costa Rica ◽  
High Elevations ◽  
A New Species

A new species of Pteris from Costa Rica is described here. Pteris arbelaeziana A. Rojas that differs from P. muricatopedata A. Arbeláez because it has longer rhizome and stipe scales, pinnate blade and distributed at high elevations. Pteris caridadiae Testo & J. E. Watkins differs from Pteris livida Mett. by its narrower rhizome and stipe scales, the stipe scales densely covering throughout, basal pinnae bifurcate with smaller basiscopic pinna and shorter apical pinna in relation with lateral ones.

scholarly journals Harwood's Francolin Francolinus harwoodi: recent observations on its status, distribution, habitat requirements, behaviour and threats

1997 ◽  
Vol 7 (3) ◽  
pp. 275-282 ◽  
Author(s):  
P.A. Robertson ◽  
Yilma Dellelegn ◽  
Sileshi Dejene ◽  
Anteneh Shimelis ◽  
Tadesse W/mariam ◽  
...  
Keyword(s):  
Breeding Season ◽  
Rainy Season ◽  
Local Communities ◽  
Maximum Density ◽  
Habitat Requirements ◽  
Small Range ◽  
Restricted Range ◽  
Essential Requirement ◽  
Administrative Region ◽  
Transect Counts

In May 1996 the authors carried out surveys of Harwood's Francolin Francolinus harwoodi, a threatened and restricted-range species, within the upper reaches of the Abay Basin, North Shoa Administrative Region, Ethiopia. The species is known from a small range in the Abay Basin but has not been reliably recorded away from a single site in the Jema Valley since 1930. Harwood's Francolin was found in the Jema Valley and valleys of adjacent river systems and, according to local reports, its range extends northwards into Southern Wello Administrative Region, a northerly extension of its previously known range. The species was found to be locally abundant, with transect counts giving a maximum density estimate of 92 birds/km2.Typha beds had been considered a crucial element in the species's habitat, but our observations suggest that although Typha beds are sometimes used they are not an essential requirement. The main threat to the species's survival appears to be from clearance of thorn scrub rather than from clearance of Typha beds. Additional threats come from hunting for food and for sale at market, and collection of eggs.Observations of courtship and mating in May and local reports of eggs in October indicate an earlier start to the breeding season than previously reported (first egg dates in December). The species may have two broods or have an extended, non-synchronous breeding season, timed to coincide with the rainy season and early dry season (May-December). Birds were observed to be highly gregarious and observations of courtship suggest that the species may be polygamous.Recommendations are given for the conservation of the species, including further survey work and collaboration with local communities to identify and protect key areas of habitat.

Techniques for tracking amphibians: The effects of tag attachment, and harmonic direction finding versus radio telemetry

2007 ◽  
Vol 28 (3) ◽  
pp. 367-376 ◽  
Author(s):  
Ross Alford ◽  
Jodi Rowley
Keyword(s):  
Home Range ◽  
Habitat Use ◽  
Radio Telemetry ◽  
Direction Finding ◽  
Reliable Data ◽  
Microhabitat Use ◽  
Using Data ◽  
Movement Parameters

AbstractTo gain information on the microhabitat use, home range and movement of a species, it is often necessary to remotely track individuals in the field. Radio telemetry is commonly used to track amphibians, but can only be used on relatively large individuals. Harmonic direction finding can be used to track smaller animals, but its effectiveness has not been fully evaluated. Tag attachment can alter the behaviour of amphibians, suggesting that data obtained using either technique may be unreliable. We investigated the effects of external tag attachment on behaviour in the laboratory by observing 12 frogs for five nights before and five nights after tag attachment, allowing one night to recover from handling. Tag attachment did not affect distance moved or number of times moved, indicating that the effects of tag attachment are unlikely to persist after the first night following attachment. We then compared harmonic direction finding and radio-telemetry using data collected in the field. We fitted rainforest stream frogs of three species with tags of either type, located them diurnally and nocturnally for approximately two weeks, and compared movement parameters between techniques. In the field, we obtained fewer fixes on frogs using harmonic direction finding, but measures of movement and habitat use did not differ significantly between techniques. Because radio telemetry makes it possible to locate animals more consistently, it should be preferred for animals large enough to carry radio tags. If harmonic direction finding is necessary, it can produce reliable data, particularly for relatively sedentary species.

scholarly journals Are Tropical Reptiles Really Declining? A Six-year Survey of Snakes in Drake Bay, Costa Rica, and the Role of Temperature, Rain and Light

2019 ◽  
Author(s):  
José Pablo Barquero-González ◽  
Tracie L. Stice ◽  
Gianfranco Gómez ◽  
Julian Monge-Najera
Keyword(s):  
Costa Rica ◽  
Environmental Factors ◽  
Sea Level ◽  
Tropical Rainforest ◽  
Number Of Species ◽  
Transect Counts ◽  
Number Of Individuals ◽  
Diet Type

Introduction: studies in the last two decades have found declining snake populations in both temperate and tropical sites, including informal reports from Drake Bay, Costa Rica. Objective: to investigate if reports of decreasing snake populations in Drake Bay had a real basis, and if environmental factors, particularly temperature, rain and light, have played a role in that decrease. Methods: we worked at Drake Bay from 2012 through 2017 and made over 4000 h of transect counts. Using head flashlights we surveyed a transect covered by lowland tropical rainforest at an altitude of 12–38 m above sea level, near the Agujas River, mostly at 1930–2200 hours. We counted all the snakes that we could see along the transect. Results: snake counts increase from August to September and then decline rapidly. The May snakes/rainfall peaks coincide, but the second snake peak occurs one month before the rain peak; we counted more snakes in dry nights, with the exception of Imantodes cenchoa which was equally common despite rain conditions. We saw less Leptodeira septentrionalis on bright nights, but all other species were unaffected. Along the six years, the number of species with each diet type remained relatively constant, but the number of individuals declined sharply for those that feed on amphibians and reptiles. We report Rhadinella godmani, a highland species, at 12–38 m of altitude. Conclusion: night field counts of snakes in Drake Bay, Costa Rica, show a strong decline from 2012 through 2017.

scholarly journals Checklist of the vascular flora of Reserva Biológica San Luis, Costa Rica

Check List ◽  
2016 ◽  
Vol 12 (2) ◽  
pp. 1859 ◽  
Author(s):  
José Esteban Jiménez ◽  
Pedro Juárez ◽  
Armando Díaz
Keyword(s):  
Costa Rica ◽  
Protected Area ◽  
Vascular Plants ◽  
Life Forms ◽  
Vascular Flora ◽  
San Luis ◽  
The Pacific ◽  
Pacific Side

The Reserva Biológica San Luis is a small protected area located on the Pacific side of the Cordillera de Tilarán, northwestern Costa Rica, with a forest transitioning between the basal and premontane floras according to Holdridge’s Life Zones. An inventory of the vascular flora of the reserve was performed by collecting botanical samples during three years and consulting the databases of the CR, INB, MO and USJ herbaria. We report 130 families, 477 genera and 716 species of native vascular plants. Angiosperms comprise the largest group with 94.3%, followed by Pteridophytes 5.4% and Lycophytes 0.3%. The best represented life forms are herbaceous and arborescent with 35.7% and 26.8% respectively. Fabaceae and Piper are the most diverse family and genus, with 67 and 15 species respectively. Despite occupying 0.000049% of the total area of Costa Rica, this reserve protects approximately 7.3% of the vascular plants of the country.

scholarly journals Characterising the foraging ecology and mercury exposure of the Nationally Critical Whenua Hou diving petrel

2021 ◽  
Author(s):  
Grace Tocker
Keyword(s):  
Breeding Season ◽  
Trophic Level ◽  
Interannual Variation ◽  
Prey Species ◽  
Foraging Ecology ◽  
Isotope Analysis ◽  
Mercury Exposure ◽  
Potential Threat ◽  
Breeding Seasons ◽  
Diving Petrel

<p>With seabird species in decline globally, significant research has gone into characterising their key prey species and foraging areas that need protection. Knowledge on the diet of a species has important implications for the development of conservation programmes. The sand dune system on Whenua Hou is home to the endemic Whenua Hou diving petrel (Pelecanoides whenuahouensis; hereafter WHDP) and a population of common diving petrels (Pelecanoides urinatrix; hereafter CDP). The WHDP is considered ‘Nationally Critical’ due to its small population size (~200 individuals) and restricted breeding range (0.018 km2) on Whenua Hou. The foraging ecology of the WHDP is relatively unknown, as is its exposure to sources of marine pollution. This thesis aimed to characterise the foraging ecology of the WHDP, the potential interspecific competition with the sympatric CDPs, the prey present in the diets of each species, and their resulting exposure to mercury from the environment. In chapter 2, I used stable isotope analysis to infer the trophic dynamics of the WHDP. By sampling and analysing both blood and feathers, I was able to investigate potential differences in WHDP foraging ecology between the breeding and non-breeding seasons. I found a difference between the foraging ecology of male and female WHDPs, with results indicating females forage further out to sea than males and on prey of lower trophic value. I found that WHDPs forage an entire trophic level higher during the breeding season than the non-breeding season. As my sampling effort spanned three consecutive breeding seasons (2017-2019), I was able to detect interannual variation in the foraging ecology of WHDPs. The results revealed that WHDPs foraged at a higher trophic level during the breeding season of 2018 compared to that of 2017 or 2019. By characterising the isotopic niches of both the WHDPs and CDPs over the three years, I was able to demonstrate a degree of trophic segregation between the two species during the breeding season. In chapter 3, I designed and went through the initial development stages for a novel multiplex-PCR assay to identify the prey species present in the diets of WHDPs and CDPs. The obstacles faced in the development of this protocol highlighted the suitability of DNA metabarcoding as an alternative method. In chapter 4, I analysed the mercury concentration in the same blood and feather samples used for stable isotope analysis. I demonstrated that male WHDPs had higher concentrations of mercury in their tissues than females, correlating with their foraging at a higher trophic level. The interannual variation in mercury concentration did not correlate with the trophic variation of WHDPs among years, indicating that the environmental fluctuations in mercury levels had a stronger effect on mercury exposure than diet. WHDP tissues consistently had higher concentrations of mercury than CDPs, correlating with their isotopic niche segregation and highlighting a potential threat to individual survival and reproductive success in WHDPs. Overall, my results describe patterns in the foraging ecology of the WHDP, as well as highlighting the potential threat from mercury exposure. This research can be used as a baseline for future investigations into the key prey species for the endangered WHDP and the impacts mercury exposure may be having on the population growth of this species. </p>

scholarly journals The Universal War Strategy in the 5th Generation War in the 4.0 Industry Era (Cyber Threat Case Study)

2020 ◽  
Author(s):  
Richmond Sam-Quarm ◽  
Mohamed Osman Elamin Busharads
Keyword(s):  
Research Method ◽  
Human Life ◽  
Cyber Attacks ◽  
Cyber Warfare ◽  
Potential Threat ◽  
Descriptive Phenomenology ◽  
Cyber Threats ◽  
Qualitative Descriptive ◽  
Using Data ◽  
The Stability

Currently, the world has entered into the 5th generation war, and this war in the 5th generation can be said to be an invisible war. This war can be interpreted as an information war, an economic war, including cyber warfare. The rapid progress of the development of science and technology today has a very broad impact on various aspects of human life. The threat of cyber attacks that can cripple the stability of national security needs to be watched out for. For this reason, the Indonesian nation must have strategic steps to anticipate all possibilities from the threat of cyber attacks. The research objective in this paper is to identify the potential threat of 5th generation war, analyze cyber threats and cyber attacks in Indonesia and how the Universal War Strategy in dealing with the threat of cyber attacks. This research method uses a qualitative descriptive phenomenology research method, using data sources from some literature and mass media. The research results from the researcher's analysis provide significant results with the conclusion that Indonesia is vulnerable to cyber threats so that it is necessary to equalize perceptions in drafting the concept of defense and security from the threat of cyber attacks.

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