scholarly journals A Study of The Effect Of Understorey Foliage Density On Bat Diversity and Abundance In The Guyana Shield Rainforest

2021 ◽  
Vol 3 (5) ◽  
pp. 16-21
Author(s):  
Juliet I. M. Russell
Keyword(s):  
Foliage Density ◽  
Bat Diversity

A new path loss model based on the volumetric occupancy rate for the pine forests at 5G frequency band

2020 ◽  
pp. 1-10
Author(s):  
Abdullah Genc
Keyword(s):  
Path Loss ◽  
Forest Area ◽  
Occupancy Rate ◽  
Loss Model ◽  
Path Loss Model ◽  
Model Based ◽  
Proposed Model ◽  
Pine Trees ◽  
Foliage Density ◽  
Reference Measurements

Abstract In this paper, a new empirical path loss model based on frequency, distance, and volumetric occupancy rate is generated at the 3.5 and 4.2 GHz in the scope of 5G frequency bands. This study aims to determine the effect of the volumetric occupancy rate on path loss depending on the foliage density of the trees in the pine forest area. Using 4.2 GHz and the effect of the volumetric occupancy rate contributes to the literature in terms of novelty. Both the reference measurements to generate a model and verification measurements to verify the proposed models are conducted in three different regions of the forest area with double ridged horn antennas. These regions of the artificial forest area consist of regularly sorted and identical pine trees. Root mean square error (RMSE) and R-squared values are calculated to evaluate the performance of the proposed model. For 3.5 and 4.2 GHz, while the RMSEs are 3.983 and 3.883, the values of R-squared are 0.967 and 0.963, respectively. Additionally, the results are compared with four path loss models which are commonly used in the forest area. The proposed one has the best performance among the other models with values 3.98 and 3.88 dB for 3.5 and 4.2 GHz.

scholarly journals Intact forests of the Hkakabo Razi Landscape are a hotspot of bat diversity in South-east Asia

Oryx ◽  
2021 ◽  
pp. 1-6
Author(s):  
Paul J. J. Bates ◽  
Pipat Soisook ◽  
Sai Sein Lin Oo ◽  
Marcela Suarez-Rubio ◽  
Awatsaya Pimsai ◽  
...  
Keyword(s):  
East Asia ◽  
New Records ◽  
World Heritage Site ◽  
South East Asia ◽  
Land Area ◽  
Heritage Site ◽  
Bat Conservation ◽  
Distribution And Ecology ◽  
Bat Diversity ◽  
High Diversity

Abstract The Hkakabo Razi Landscape, in northern Kachin, Myanmar, is one of the largest remaining tracts of intact forest in South-east Asia. In 2016, we undertook a survey in its southern margins to assess bat diversity, distribution and ecology and evaluate the importance of the area for global bat conservation. Two collecting trips had taken place in the area in 1931 and 1933, with four bat species reported. We recorded 35 species, 18 of which are new for Kachin. One species, Murina hkakaboraziensis, was new to science and three, Megaerops niphanae, Phoniscus jagorii, Murina pluvialis, were new records for Myanmar. Our findings indicate high bat diversity in Hkakabo Razi; although it comprises only 1.7% of Myanmar's land area, it is home to 33.6% of its known bat species. This emphasizes Hkakabo Razi's importance for conserving increasingly threatened, forest-interior bats, especially in the families Kerivoulinae and Murininae. There is also a high diversity of other mammals and birds within the Hkakabo Razi Landscape, which supports its nomination as a World Heritage Site.

scholarly journals Bat species richness in the region of the Central Valleys of Oaxaca, Mexico

2019 ◽  
pp. 1-11
Author(s):  
M. García–Luis ◽  
M. Briones–Salas ◽  
M. C. Lavariega
Keyword(s):  
Species Richness ◽  
Iucn Red List ◽  
Red List ◽  
Risk Category ◽  
Echolocation Calls ◽  
Mustached Bat ◽  
Pteronotus Parnellii ◽  
Urbanized Region ◽  
Bat Diversity

We present a revised checklist of bat species occurring in the semi–urbanized region of the Central Valleys of Oaxaca, Mexico. The checklist is based on surveys using mist nets, recordings of echolocation calls, data from literature, and museum databases. Results show that the Central Valleys of Oaxaca have a species richness of 33 bat species belonging to 22 genera and five families. Species like the Mustached bat Pteronotus parnellii, the Western Red bat Lasiurus blossevillii and the Free–tailed bat Promops centralis were recorded after 32, 30 and 19 years respectively according to the records of the literature. We also recorded four species classified in some risk category according to either the Mexican government’s red list (NOM–059) or the IUCN red list. The recordings of the echolocation calls are the first from the region of Central Valleys of Oaxaca. Bat diversity in the Central Valleys of Oaxaca was underestimated and emphasizes the need for further research

Song pitch – habitat relationships in white-throated sparrows: cracks in acoustic windows?

1988 ◽  
Vol 66 (11) ◽  
pp. 2578-2581 ◽  
Author(s):  
Joseph R. Waas
Keyword(s):  
Boreal Forest ◽  
Inverse Relationship ◽  
Habitat Type ◽  
Zonotrichia Albicollis ◽  
Acoustic Window ◽  
Wrong Reason ◽  
Foliage Density ◽  
The Right ◽  
Forest Habitats

I compared the hypothesis that birds singing from song posts above 1–2 m should sing in as low a pitch as possible regardless of habitat type, with the traditional "acoustic window" hypothesis which argues that selection favours an inverse relationship between song pitch and foliage density. Songs of white-throated sparrows, Zonotrichia albicollis, were obtained from four habitats which could be arranged in a gradient of foliage density. The pitch of these songs was found to be inversely related to the density of foliage in the habitat occupied, consistent with the acoustic window hypothesis. Significant pitch variation occurred not only between open and forest habitats, but also between mixed and boreal forest habitats. I distinguish between hypotheses that could explain support for the traditional hypothesis despite recent data suggesting that low pitched sound travels best regardless of habitat at song post heights used by white-throated sparrows (5–10 m). I conclude that the acoustic window model may make the right prediction for the wrong reason in white-throated sparrows. I emphasize the need to define and test the assumptions of models before the models themselves are accepted on the basis of support for their predictions.

scholarly journals Bat diversity of Ilha da Marambaia, Southern Rio de Janeiro State, Brazil (Chiroptera, Mammalia)

2010 ◽  
Vol 70 (3) ◽  
pp. 511-519 ◽  
Author(s):  
EC. Lourenço ◽  
LM. Costa ◽  
RM. Silva ◽  
CEL. Esbérard
Keyword(s):  
Rio De Janeiro ◽  
Abundant Species ◽  
Water Bodies ◽  
Abundance Patterns ◽  
Molossus Molossus ◽  
Bat Diversity ◽  
Janeiro State

Few sites have been well sampled for bats, and samplings in islands are even scarcer. Therefore, the objectives of the present study were: (1) to list the bat species of Ilha da Marambaia; (2) to compare richness, abundance and biomass of bat guilds found there; (3) to analyse abundance patterns of bat species; and (4) to compare richness, abundance and composition of the bat fauna among different kinds of environment. To capture bats we used mist nets set in five different environments, totalising 3559.2 net-hours, during 37 nights between October 2006 and August 2008. A total of 1,133 captures were accomplished, comprising 34 species from five families. The most abundant species was Molossus molossus. Frugivorous bats exhibited higher richness, abundance and biomass if compared to other guilds. Most species (N = 22) exhibited abundances between 1 to 10% of all captures. Sixteen species were restricted to just one of the environments sampled. The high richness may be attributed to sampling carried out in several environments, and to the capture of insectivorous species over water bodies.

Positive edge effects for arboreal marsupials: an assessment of potential mechanisms

2006 ◽  
Vol 33 (2) ◽  
pp. 121 ◽  
Author(s):  
Elaine K. Harding ◽  
Shirin Gomez
Keyword(s):  
Edge Effects ◽  
Brushtail Possum ◽  
Strongly Correlated ◽  
Positive Edge ◽  
Relative Index ◽  
Arboreal Marsupials ◽  
Pellet Counts ◽  
Wet Tropics ◽  
Foliage Density ◽  
Ringtail Possum

In this study we examined the potential for positive edge effects on folivorous arboreal marsupials inhabiting upland rainforest in the Wet Tropics region of far north Queensland, Australia. We predicted that the folivores should have increased densities at edges relative to interior forest 90 m from the edge owing to the following causal factors, either separately or in combination: (a) increased foliar biomass, measured as vertical foliage density; and/or (b) increased abundance of preferred food trees. To test these hypotheses, we conducted surveys of the lemuroid ringtail possum (Hemibelideus lemuroides), the green ringtail possum (Pseudochirops archeri), the Herbert River ringtail possum (Pseudochirulus herbertensis) and the coppery brushtail possum (Trichosurus vulpecula johnstonii) at two remnant rainforest sites with ‘hard’ edges such as roads or pasture. Because arboreal species are often difficult to survey accurately within forests, we utilised pellet counts as an index of the population and compared this to the common survey technique of night spotlighting. Our results indicated that pellet counts, combined over all species, were positively and strongly correlated with spotlighting results. Using pellet counts as a relative index of arboreal folivore populations, we found that edge transects contained a higher abundance of all species combined than did interior transects. Further, total foliage density in the 10–30-m vertical transect was found to be significantly correlated with total pellet counts at edge transects. Total preferred tree species was not significantly different between edge and interior transects. From these results we propose that foliage density, as a surrogate for biomass, is a possible mechanism explaining the higher abundance of arboreal marsupials at the edges of these two highland rainforest sites in north Queensland.

scholarly journals Bats Diversity in Kolej Universiti Sains dan Teknologi Malaysia (KUSTEM)

2013 ◽  
Vol 1 (3) ◽  
pp. 1-6
Author(s):  
Widad Fadhullah ◽  
Wong Chee Ho
Keyword(s):  
Species Identification ◽  
Simpson Index ◽  
The Family ◽  
Total Capture ◽  
Cynopterus Brachyotis ◽  
Bat Diversity

The study of bats diversity was conducted in Kolej Universiti Sains dan Teknologi Malaysia (KUSTEM) from July until December 2004. The objective is to examine the diversity of bat species in KUSTEM area for conservation purpose. Ten mist nets were used as the capturing device. Species identification was based on the forearm measurement, weight, sex, maturity status and their reproduction. Bats were released after identification. A total of 99 individual bats were captured, comprising of two families and four species. Three species were frugivorous bats, Cynopterus brachyotis, Cynopterus horsfieldii and Eonycteris major from the family Pteropodidae. One insectivorous species, Kerivoulla papillosa was captured from the family Vespertillionidae. Cynopterus brachyotis is the highest captured individual and species, representing 70.97% of total capture. Shannon-Weiner index is 0.8569 and Simpson index is 0.4504. The bat diversity in KUSTEM is influenced by the capture device and duration of study.

Characterization of damage and biotic factors associated with the decline of Eucalyptus wandoo in southwest Western Australia

2005 ◽  
Vol 35 (11) ◽  
pp. 2589-2602 ◽  
Author(s):  
Ryan J Hooper ◽  
K Sivasithamparam
Keyword(s):  
Western Australia ◽  
Partial Harvest ◽  
Foliage Density ◽  
Density Ratios ◽  
The Relationship ◽  
Mixed Age ◽  
Eucalyptus Wandoo

Crown decline of wandoo, Eucalyptus wandoo, in southwest Western Australia has escalated over the last 10 years, so very few unaffected stands remain. To assess the canopy-damage characteristics of trees in decline a destructive, partial-harvest method was used to sample branches in natural mixed-age stands. Necrosis of common cankers was closely associated with type-1 borer damage, characterized by "longitudinal" gallery structure on declining trees only. Cankers were found to be consistently more severe on declining trees, with decay regions affecting a greater proportion of sapwood tissue. Several infestations causing type-1 borer damage that varied in age were found on declining branches, providing evidence of cyclical damage events. Type-2 borer damage characterized by "ring-barking" gallery structure caused extensive damage in canopies, but was not always associated with decline. Interactions between foliage density and canker score showed that 17.8% and 63.1% of the variability in foliage-density ratios was accounted for in declining intermediate-health and unhealthy classes, respectively. The relationship was negligible for the healthy class (9.9%), providing strong evidence that cankers are causing foliage loss in declining canopies. Evidence suggests that an interaction between type-1 borer infestations and decay-causing fungi is responsible for the decline in E. wandoo wandoo canopies.

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