scholarly journals How rare is rare? Quantifying and assessing the rarity of the bush dog Speothos venaticus across the Amazon and other biomes

Oryx ◽  
2016 ◽  
Vol 52 (1) ◽  
pp. 98-107 ◽  
Author(s):  
Tadeu G. de Oliveira ◽  
Fernanda Michalski ◽  
André L. M. Botelho ◽  
Lincoln J. Michalski ◽  
Armando M. Calouro ◽  
...  
Keyword(s):  
Central America ◽  
Relative Abundance ◽  
Habitat Structure ◽  
Field Data ◽  
Brazilian Amazon ◽  
Camera Trap ◽  
Population Parameters ◽  
The Mean ◽  
Bush Dog ◽  
Speothos Venaticus

AbstractThe bush dog Speothos venaticus is a medium-sized Neotropical canid. It is considered to be rare and its biology and population parameters are still poorly understood. The Amazon is one of the main strongholds of this species and is important for maintaining viable populations, as the region still holds extensive tracts of pristine habitat. We gathered field data from camera-trap studies throughout the Brazilian Amazon to estimate the relative abundance of the species and gain an understanding of its rarity, and how this compares with estimates from other vegetative formations and for sympatric hypercarnivores. We focused on three pristine or partially disturbed sites and one fragmented site. The estimated relative abundance of the species was 0.060–0.185 individuals per 100 trap-days, confirming that the species is rare. The bush dog's abundance in the Amazon is equivalent to that in all other areas outside the Basin. The mean group size recorded was c. 2.5 individuals. There were no differences in group sizes between forests in the Amazon and in other regions of Central America; however, there were significant differences between forests and open habitats. A combination of competition/predation, habitat structure/integrity, and disease may be acting synergistically in determining the abundance and rarity of bush dogs.

scholarly journals New camera-trap records for bush dog (Speothos venaticus) in Colombia

2017 ◽  
Vol 29 ◽  
pp. 19-22 ◽  
Author(s):  
Paola Rodríguez-Castellanos ◽  
Germán Garrote ◽  
Fernando Trujillo
Keyword(s):  
Camera Trap ◽  
Bush Dog ◽  
Speothos Venaticus

First photographic records of bush dogs (Speothos venaticus) from camera-traps in Guyana

Mammalia ◽  
2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Matthew T. Hallett ◽  
Anthony Roberts ◽  
Ashley P. Holland ◽  
Angus Jackman
Keyword(s):  
Camera Trap ◽  
Camera Traps ◽  
Individual Study ◽  
Detection Rates ◽  
Detailed Measurement ◽  
Scale Modelling ◽  
In The Wild ◽  
Bush Dog ◽  
Speothos Venaticus ◽  
Photographic Records

AbstractThe bush dog (Speothos venaticus) is rare, elusive, and difficult to study in the wild. Guyana contains a wealth of intact tropical forest (∼18.4 million ha) and savanna (1.6 million ha) habitats, but management of this species is hindered by a lack of data. We present two photographic records (consisting of nine individuals) of bush dogs from camera-traps set in the Kanuku Mountains Protected Area (KMPA) – the first of this species in Guyana. These records highlight the importance of Guiana Shield forests and Guyana’s expanding protected areas system to the conservation of these wide-ranging carnivores. Additionally, we recommend that detailed measurement and reporting of site variables become standard, as it will improve the efficacy of camera-trap studies of bush dogs and allow for broad-scale modelling of space use not otherwise possible due to the low detection rates at the scale of each individual study.

Long-term effects of anthropogenic habitat disturbance on a lizard assemblage inhabiting coastal dunes in Argentina

2000 ◽  
Vol 78 (9) ◽  
pp. 1653-1660 ◽  
Author(s):  
Laura E Vega ◽  
Patricio J Bellagamba ◽  
Lee A Fitzgerald
Keyword(s):  
Relative Abundance ◽  
Habitat Structure ◽  
Coastal Dunes ◽  
Microhabitat Use ◽  
Long Term Effects ◽  
Drastic Reduction ◽  
Anthropogenic Habitat ◽  
The Mean ◽  
Induced Changes

We studied abundance and habitat use in two species of Liolaemus (Squamata: Tropiduridae) at a coastal dune site in eastern Argentina before and 7 years after a road was built at the site. Before disturbance, lizards exhibited similar abundances and a wide segregation in microhabitat use. Liolaemus multimaculatus used flat dunes scarcely covered by Spartina ciliata, while Liolaemus gracilis used the grass Panicum racemosum as cover. After disturbance, the mean number of L. multimaculatus detected by month was significantly less than that observed in the predisturbance period, owing to a drastic reduction in S. ciliata microhabitat patches. The mean number of L. gracilis was similar to that seen during the first period. These differences were clearly linked to habitat loss at the site. We concluded that human impact on the habitat structure of foredunes induced changes in the structure of the lizard assemblage, including shifts in the relative abundance of species and the proportional use of their preferred microhabitats.

scholarly journals Bush Dogs in Central America: Recent Range Expansion, Cryptic Distribution, or Both?

2019 ◽  
Vol 12 ◽  
pp. 194008291984975 ◽  
Author(s):  
Carolina Sáenz-Bolaños ◽  
Todd K. Fuller ◽  
Michael S. Mooring ◽  
Junior Porras ◽  
Paul R. Sievert ◽  
...  
Keyword(s):  
Central America ◽  
National Park ◽  
Potential Range ◽  
Low Density ◽  
Substantial Portion ◽  
East Central ◽  
Repeated Observations ◽  
The North ◽  
Bush Dog ◽  
Speothos Venaticus

Bush dogs ( Speothos venaticus) are a small, wide-ranging neotropical pack-hunting canid whose ecology is relatively poorly known. Here, we document new, repeated observations of bush dog groups in east-central (Barbilla National Park) and south-eastern (La Amistad International Park) Costa Rica that suggest either that their recent or historic range has been underestimated, or that their potential range in Central America may have recently expanded and could now include not only borderlands with Panama but perhaps a substantial portion of the Talamanca Mountains up to 120 km to the north-northwest and at elevations up to 2,119 m. In light of their inherently low density, documenting the current and future distribution of bush dogs in Central America will be challenging.

scholarly journals Regionally extinct species rediscovered: the bush dog Speothos venaticus in Minas Gerais, south-eastern Brazil

Oryx ◽  
2014 ◽  
Vol 49 (1) ◽  
pp. 60-63 ◽  
Author(s):  
Guilherme Braga Ferreira ◽  
Marcelo Juliano Rabelo Oliveira ◽  
Rogério Cunha de Paula ◽  
Flávio Henrique Guimarães Rodrigues ◽  
Érica Daniele Cunha Carmo
Keyword(s):  
Protected Areas ◽  
Minas Gerais ◽  
The State ◽  
South American ◽  
North West ◽  
South Eastern ◽  
The North ◽  
Eastern Brazil ◽  
Bush Dog ◽  
Speothos Venaticus

AbstractThe bush dog Speothos venaticus, a rare Near Threatened South American canid that lives in packs, was thought to be extinct in Minas Gerais state, south-eastern Brazil, until recently. Here, we report four recent records of the species in Minas Gerais, the first in the state since the description of the species in 1842. All records are from the Cerrado ecosystem in the north and north-west of the state; two are from animals found dead, one from footprints and another from a camera trap. Three of the records were inside or close (< 10 km) to strict protected areas, in a region recognized as the Protected Areas Mosaic Sertão Veredas–Peruaçu, where we expect any new records of the bush dog to be found. We discuss the low probability of detecting the bush dog and the main regional threats to the species, and emphasize the need to protect large and interconnected natural areas and keep them free of domestic dogs to avoid the extinction of the bush dog in Minas Gerais.

Population parameters of ringed seals (Phoca hispida Schreber, 1775) in the Svalbard area

1987 ◽  
Vol 65 (4) ◽  
pp. 1021-1027 ◽  
Author(s):  
Christian Lydersen ◽  
Ian Gjertz
Keyword(s):  
Sex Ratio ◽  
Ringed Seal ◽  
Adult Males ◽  
Population Parameters ◽  
Phoca Hispida ◽  
Age Class ◽  
Ringed Seals ◽  
Males And Females ◽  
The Mean ◽  
Sexually Mature

Samples were taken from 284 ringed seals (Phoca hispida) in the Svalbard area during April–July 1981 and March–April 1982. The age of 283 seals was determined by reading annuli in the cementum of the canine teeth. The mean age of the males was 11.3 years, and of the females, 14.9 years. Females were found to be significantly older than males. The mean length of sexually mature ringed seals was 128.9 cm for both sexes. The mean weight of adult males and females was 53.5 and 61.4 kg, respectively. Females were found to be significantly heavier than males. The sex ratio was 47.8% males and 52.2% females. Studies of microscopic sections of testis and epididymis from ringed seal males showed that 63, 75, and 80% of 5-, 6-, and 7-year-old animals, respectively, were sexually mature. The weights of testis and epididymis, diameters of tubuli, and the size of testis all showed a marked increase in the 5-year age-class. Macroscopic sections of ovaries from ringed seal females showed that 20, 60, and 80% of 3-, 4-, and 5-year-old animals, respectively, were sexually mature. The size of the ovaries showed a marked increase in the 5-year age-class. The ovulation rate of ringed seals from Svalbard was calculated to be 0.91.

scholarly journals MEASUREMENT OF SEDIMENT SUSPENSION IN COMBINATIONS OF WAVES AND CURRENTS

1972 ◽  
Vol 1 (13) ◽  
pp. 55
Author(s):  
J. Kirkegarrd Jensen ◽  
Torben Sorenson
Keyword(s):  
Thin Layer ◽  
Concentration Profile ◽  
Field Data ◽  
Concentration Profiles ◽  
Sediment Suspension ◽  
Calculated Concentration ◽  
Waves And Currents ◽  
The Mean ◽  
Mean Concentration ◽  
Good Agreement

The paper describes a procedure for obtaining field data on the mean concentration of sediments in combination of waves and currents outside the breaker zone, as well as some results of such measurements. It is assumed that the current turbulence alone is responsible for the maintenance of the concentration profile above a thin layer close to the bottom, in which pick-up of sediments due to wave agitation takes place. This assumption gives a good agreement between field data and calculated concentration profiles.

scholarly journals Sources of resistance to Crinipellis perniciosa in progenies of cacao accessions collected in the Brazilian Amazon

2006 ◽  
Vol 63 (6) ◽  
pp. 572-578 ◽  
Author(s):  
Valéria Rodrigues Lavigne de Mello Paim ◽  
Edna Dora Martins Newman Luz ◽  
José Luís Pires ◽  
Stela Dalva Vieira Midlej Silva ◽  
Jorge Teodoro de Souza ◽  
...  
Keyword(s):  
Resistance Genes ◽  
Integrated Management ◽  
Durable Resistance ◽  
Brazilian Amazon ◽  
Sources Of Resistance ◽  
Crinipellis Perniciosa ◽  
Broom Disease ◽  
The Mean ◽  
The Stability ◽  
Different Sources

The witches' broom disease caused by the fungus Crinipellis perniciosa is the main phytossanitary constraint for cacao production in Brazil. The integrated management of the disease involves resistance as one of the components. The breeding program conducted by the Brazilian Institution, CEPLAC is directed toward the pyramidation of resistance genes from different sources to achieve a more durable resistance. This study aimed to identify sources of resistance in progenies of cacao accessions collected in the basins of ten Amazonian rivers and compared to progenies from the Peruvian clones 'Scavina 6' and 'Sacavina 12'. Progenies from 40 Amazonian accessions and 'Scavina' were evaluated in the field for six years for witches' broom resistance through multivariate and repeated measurement analyses evaluating the effect of progeny, area, block, year, and their interactions. There were differences in the mean number of vegetative brooms on some Amazonian progenies and 'Scavina' descendants. There was an increase in the number of vegetative brooms in the last year for 'Scavina' progenies, but that was not observed for the Amazonian progenies 64, 66, 156, 194, 195, 269 and 274. There were different gene/alleles for resistance in the Amazonian progenies in comparison to the traditional 'Scavina' accessions. These new sources of resistance will be important for pyramiding resistance genes and consequently increasing the stability and durability of the resistance to witches' broom.

scholarly journals The influence of shelterbelts in arable farmland on beneficial and pest invertebrates

2015 ◽  
Vol 68 ◽  
pp. 367-372
Author(s):  
M.M. Davidson ◽  
B.G. Howlett ◽  
R.C. Butler ◽  
N.M. Taylor ◽  
M.K. Walker
Keyword(s):  
Relative Abundance ◽  
Pest Species ◽  
Pitfall Traps ◽  
Arable Crops ◽  
Beneficial Insects ◽  
Arable Farmland ◽  
The Mean ◽  
Beneficial Insect ◽  
Abundance And Diversity ◽  
On Farm

Shelterbelts of Pinus radiata and Cupressus macrocarpa are common landscape features on arable farmland in New Zealand This study aimed to determine whether such shelterbelts could influence the relative abundance and diversity of beneficial and pest invertebrates commonly found in arable crops Window intercept yellow sticky and pitfall traps were placed next to shelterbelts or post and wire fences and also 50 m from these borders into adjacent crops on two arable farms in Canterbury and one in Wairarapa over 12 weeks in summer 2012 and autumn 2013 The abundance of given species/taxa varied considerably depending on farm location season and field border type However the mean number of beneficial insect species/taxa per trap did not vary markedly between field border types or adjacent crops while traps at shelterbelts or their adjacent crops caught more of some pest species/taxa than traps beside fences The pine/macrocarpa shelterbelts did not markedly increase relative abundance or diversity of beneficial insects

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