scholarly journals The α-minimum convex polygon as a relevant tool for isotopic niche statistics

2021 ◽  
Vol 130 ◽  
pp. 108048
Author(s):  
Pauline Fey ◽  
Yves Letourneur ◽  
Silvère Bonnabel
Keyword(s):  
Convex Polygon ◽  
Isotopic Niche ◽  
Minimum Convex Polygon

scholarly journals Distribution update, conservation status and color in life of the rare Amazonian snake, Eutrachelophis papilio Zaher and Prudente 2019 (Serpentes: Xenodontini)

2020 ◽  
Vol 50 (3) ◽  
pp. 252-255
Author(s):  
Nathalie CITELI ◽  
Mariana DE-CARVALHO ◽  
Reuber BRANDÃO
Keyword(s):  
Convex Polygon ◽  
Conservation Status ◽  
Biological Data ◽  
Distribution Area ◽  
Minimum Convex Polygon ◽  
Human Footprint ◽  
Data Deficient ◽  
First Time ◽  
Polygon Method ◽  
Anthropic Pressure

ABSTRACT The rare Amazonian snake Eutrachelophis papilio is known from only five individuals, from four localities, belonging to its type-series, the more recent collected over 10 years ago. Here, we expand its distribution and describe its color in life for the first time. We also provide an estimate of its distribution area using the minimum convex polygon method and identify the values of anthropic pressure within its known distribution range with the Human Footprint Index. The new occurrence is located 291 km from the nearest known locality and its distribution is associated with pristine forests. Considering its rarity, and the absence of demographic and biological data, we suggest that the species should be classified as Data Deficient by IUCN criteria.

Can minimum convex polygon home ranges be used to draw biologically meaningful conclusions?

2007 ◽  
Vol 23 (3) ◽  
pp. 635-639 ◽  
Author(s):  
Erlend B. Nilsen ◽  
Simen Pedersen ◽  
John D. C. Linnell
Keyword(s):  
Convex Polygon ◽  
Home Ranges ◽  
Minimum Convex Polygon

scholarly journals Seasonal Home Ranges of Raccoons, Procyon lotor, Using a Common Feeding Site in Rural Eastern Ontario: Rabies Management Implications

2004 ◽  
Vol 118 (1) ◽  
pp. 65 ◽  
Author(s):  
Sarah C. Totton ◽  
Richard C. Rosatte ◽  
Rowland R. Tinline ◽  
Laura L. Bigler
Keyword(s):  
Convex Polygon ◽  
Procyon Lotor ◽  
Grid Cell ◽  
Effective Area ◽  
Home Ranges ◽  
Minimum Convex Polygon ◽  
Management Implications ◽  
Feeding Site ◽  
Movement Data ◽  
Summer Maximum

Thirteen adult Raccoons (Procyon lotor) (six females, seven males) that fed at a garbage dump north of Kingston, Ontario were radio-tracked from 21 June to 16 October 1995 to assess their seasonal home ranges and movements. Average Minimum Convex Polygon (MCP) summer and fall home ranges for the collared Raccoons were 78.4 ha (SD=46.2 ha) and 45.6 ha (SD=29.7 ha), respectively. Average grid cell summer and fall home ranges for the collared Raccoons were 143.3 ha (SD=40.0 ha) and 116.9 ha (SD=24.9 ha), respectively. Summer ranges of the Raccoons were significantly larger than fall ranges using both the MCP method (P=0.05) and the grid cell method (P=0.073). Yearling Raccoons travelled an average summer maximum distance from the dump of 2608 m (SD=1964, n=3), more than double the distance of adults (≥2 yr) at 1239 m (SD=547, n=10). The population density for the study area in late August 1995 was estimated at 1 Raccoon/12 ha based on an effective area surrounding the dump of 234 ha. Home range and movement data may be useful to design a strategy to control Raccoon rabies in Ontario.

scholarly journals Primeros datos sobre Área de actividad de gato montés (Lynx rufus) en Oaxaca, México

2012 ◽  
Vol 28 (2) ◽  
Author(s):  
Gabriela Monroy ◽  
Miguel Briones-Salas
Keyword(s):  
Home Range ◽  
Protected Area ◽  
Convex Polygon ◽  
Lynx Rufus ◽  
Oak Forests ◽  
Minimum Convex Polygon ◽  
Sierra Madre ◽  
One Year

An individual of bobcat (Lynx rufus) was captured on a communal protected area at Sierra Madre de Oaxaca, Mexico and monitored through radiotelemetry for one year in order to obtain the first records of home range in South Mexico. Data were obtained by 95% Minimum Convex Polygon at the two seasons. Most radiolocations were on pine and oak forests; vegetation highly deforested and transformed.

scholarly journals Status of the eastern imperial eagle (Aquila heliaca) in the Czech Republic – 2013 update, ringing results and new findings

2014 ◽  
Vol 8 (1) ◽  
pp. 41-46
Author(s):  
David Horal
Keyword(s):  
Czech Republic ◽  
Convex Polygon ◽  
Interesting Case ◽  
Minimum Convex Polygon ◽  
The Czech Republic ◽  
New Findings ◽  
Imperial Eagle ◽  
Aquila Heliaca ◽  
Nest Height ◽  
South Moravia

Abstract Although unconfirmed reports on the breeding of the eastern imperial eagle exist from as early as in 1 920s, the first confirmed breeding only took place in 1 998. Since then, 1-5 pairs have bred annually, chiefly in the South Moravia region (the Breclav, Znojmo and the Brno-venkov districts). Out of 37 breeding attempts, 26 (i.e. 70%) were successful, with 48 young reared. The paper summarizes some characteristics of the breeding biology (productivity, breeding losses, nesting tree species, nest height, nest turnover, minimum convex polygon of the nests [nesting trees] built by individual pairs) as well as ringing recoveries. Out of 42 ringed chicks, 39 fledged successfully and produced 3 recoveries (Slovakia - 2, Austria - 1 ). Three foreign ringed birds were also sighted in the Czech Republic. The most interesting case is the breeding of a 1 9-year-old female born in eastern Slovakia (distance 336 km), found via a photo of the ring (V. Gahura, 201 3).

Gap-crossing in fragmented habitats by mahogany gliders (Petaurus gracilis). Do they cross roads and powerline corridors?

2010 ◽  
Vol 32 (1) ◽  
pp. 10 ◽  
Author(s):  
Yumiko Asari ◽  
Christopher N. Johnson ◽  
Mark Parsons ◽  
Johan Larson
Keyword(s):  
Convex Polygon ◽  
Harmonic Mean ◽  
Home Ranges ◽  
Minimum Convex Polygon ◽  
Narrow Strip ◽  
North East ◽  
Large Trees ◽  
Scattered Trees ◽  
The Mean ◽  
Gap Crossing

The mahogany glider (Petaurus gracilis) is one of the most threatened arboreal mammals in Australia. Although its habitat is affected by fragmentation, gap-crossing behaviour of the species has not been studied. A radio-tracking survey was undertaken on six individuals (three males, three females) in a woodland patch bisected by a 35.8-m-wide highway and a 31.5-m-wide powerline corridor, in north-east Queensland. The mean home ranges of males were 20.1 ± 3.3 ha, 21.3 ± 7.9 ha and 20.9 ± 8.2 ha, as measured by the Minimum Convex Polygon, Kernel and Harmonic Mean methods respectively. The mean home ranges of females were 8.9 ± 0.5 ha, 9.0 ± 4.2 ha and 8.8 ± 2.3 ha, as measured by the Minimum Convex Polygon, Kernel and Harmonic Mean methods respectively. Two males and one female were observed crossing linear gaps. However, there was less crossing than expected, and females were less likely to cross than males. One male used a narrow strip of woodland at the opposite side of the highway as supplemental habitat for foraging. This individual also used scattered trees in a grassland matrix for foraging or denning. Another male used a wooden power pole as a launching site to cross the highway. This study emphasises the importance of protecting large trees along linear barriers in open habitat, and suggests that gliding poles may be used to facilitate gap-crossing by mahogany gliders.

scholarly journals A radio tracking study of home range and movements of the marsupial Micoureus demerarae (Thomas) (Mammalia, Didelphidae) in the Atlantic forest of south-eastern Brazil

2005 ◽  
Vol 22 (1) ◽  
pp. 85-91 ◽  
Author(s):  
Edsel Amorim Moraes Junior ◽  
Adriano Garcia Chiarello
Keyword(s):  
Home Range ◽  
Convex Polygon ◽  
Home Ranges ◽  
Radio Tracking ◽  
Minimum Convex Polygon ◽  
South Eastern ◽  
Live Trapping ◽  
Eastern Brazil ◽  
Data Points ◽  
Biological Reserve

From August 2001 to July 2002 the home range and movements of seven Micoureus demerarae (Thomas, 1905) (three males and four females) were investigated using radio tracking in the União Biological Reserve, state of Rio de Janeiro, south-eastern Brazil. A total of 436 locations was obtained and home range estimated with fixed Kernel (95% of data points), and minimum convex polygon (MCP) methods, with 100 and 95% of data points. Male home ranges estimated by MCP (100%) ranged from 5.4-24.2 ha and females from 0.3-10.7 ha. Corresponding figures calculated with Kernel (95%) were 4-10.9 ha for males and 1.3-5.9 ha for females. Animals travelled on average 423 m/night, with males travelling significantly further (582.8 m/night) than females (335.1 m/night) (t test, t = 3.609, p = 0.001). We concluded that radio tracking produced much larger home ranges than those estimated with traditional live-trapping techniques, suggesting that the latter might underestimate ranging when the area covered with traps is relatively small (ca. 1 ha or less). Radio tracking also indicated that M. demerarae, although predominantly arboreal and weighting only ca. 130 g., has movements similar in magnitude to larger-sized terrestrial didelphimorph marsupials, such as Didelphis Linnaeus, 1758, Philander Linnaeus, 1758 and Metachirus (Desmarest, 1817).

Home range and activity patterns of Conepatus semistriatus (Carnivora, Mephitidae) in Emas National Park, Brazil

2014 ◽  
Vol 64 (2) ◽  
pp. 151-162 ◽  
Author(s):  
Gitana Nunes Cavalcanti ◽  
Luis Diego Alfaro-Alvarado ◽  
Flávio Henrique Guimarães Rodrigues
Keyword(s):  
Home Range ◽  
National Park ◽  
Convex Polygon ◽  
Activity Patterns ◽  
Field Research ◽  
Easy Access ◽  
Minimum Convex Polygon ◽  
Biogeographic Patterns ◽  
Local Convex ◽  
Polygon Method

Skunks (Mephitidae) have not been well studied throughout the Neotropics. In Brazil there is a general lack of data on the ecology, behavior, distribution, systematics, morphology and biogeographic patterns of the two species occurring in the country (Conepatus semistriatus and C. chinga). The focus of this study was on understanding the home range and activity patterns of C. semistriatus. Field research was conducted in the Emas National Park, where three skunks with radio-collars were located on 157 separate occasions. The observed patterns of activity indicate that the species is predominantly nocturnal, with a great expenditure of time on foraging. Temperature had a direct influence on the animal’s behavior, but there was no apparent influence of light on activity patterns. Average home range areas were 1.39 ± 0.87 km2 (Minimum Convex Polygon method) and 0.69 ± 0.25 km2 (Local Convex Hull method). There was high home range overlap between individuals, 0.27 km2 based on the Minimum Convex Polygon method, at sites with easy access to resources.

Home ranges of sympatric red-necked wallabies, red-bellied pademelons and common brushtail possums in a temperate eucalypt forestry environment.

2003 ◽  
Vol 25 (2) ◽  
pp. 183 ◽  
Author(s):  
Mar K le ◽  
C McArthur ◽  
M Statham
Keyword(s):  
Home Range ◽  
Convex Polygon ◽  
Sexual Difference ◽  
Home Range Size ◽  
Home Ranges ◽  
Sexually Dimorphic ◽  
Minimum Convex Polygon ◽  
North West ◽  
Fixed Kernel ◽  
Core Areas

We investigated home ranges of sympatric red-necked (or Bennett?s) wallabies Macropus rufogriseus rufogriseus, red-bellied pademelons Thylogale billardierii and common brushtail possums Trichosurus vulpecula fuliginosus within a forestry environment in north-west Tasmania. Six indiviuals of each species were radio-tracked between 7 and 11 months. Nocturnal and diurnal data were used to estimate Minimum Convex Polygon (MCP) home range, 95% fixed-Kernel (KE) home range and 50% KE core area. Home ranges (mean � s.e.) were as follows: M. r. rufogriseus MCP = 61 � 12 ha, KE = 41 � 3 ha; T. billardierii MCP = 22 � 5 ha, KE = 16 � 3 ha; and Tr. v. fuliginosus MCP = 39 � 8 ha, KE = 17 � 3 ha. M. r. rufogriseus had larger MCP home ranges than T. billardierii (P < 0.05), and larger KE home ranges and core areas than both T. billardierii and Tr. v. fuliginosus (P < 0.05), which reflected their larger body mass. Inter-sexual comparisons within the sexually dimorphic macropods showed that M. r. rufogriseus males had significantly larger MCP and KE home ranges and core areas than females (P < 0.05), and T. billardierii males tended to have a larger KE home ranges than females (P = 0.08). No inter-sexual difference in home range size was detected for Tr. v. fuliginosus.

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