scholarly journals Population characteristics of Akodon montensis (Sigmodontinae) in response to habitat degradation and food availability

Therya ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 5-13
Author(s):  
Julieta P. Sánchez-Martínez ◽  
Robert D. Owen
Keyword(s):  
Home Range ◽  
Food Availability ◽  
Habitat Quality ◽  
Resource Availability ◽  
Habitat Degradation ◽  
Secondary Forest ◽  
Average Density ◽  
Food Distribution ◽  
Population Characteristics ◽  
Minimum Convex Polygon

Small mammal populations can be affected by habitat degradation, causing changes in their abundance, density and movement.  Akodon montensis, a persistent host for Orthohantavirus, is a common rodent species in primary and secondary forest habitats and is considered a generalist species.  This paper analyzes how habitat degradation and resource availability affect the population characteristics of the species.  Six plots were classified into three levels of degradation, with sampling conducted in June and November 2015.  After the June sampling, three plots were selected for the increase of food resources for three months, to assess how this factor affects the population.  Abundance was estimated with the capture-mark-recapture method and density was estimated by dividing abundance by the effective sampling area.  Home range was calculated using the Minimum Convex Polygon method, and the Maximum Distance Traveled as the longest average movement between two sampling stations where an individual was encountered.  More degraded habitats supported lower average density and abundance of A. montensis compared to less degraded habitats. Increasing food availability led to increases in abundance in the more degraded habitats and decreases in the least degraded.  Changes in home range were most evident, decreasing in the least degraded plots after the increase in resources.  The sex ratio did not differ from equity in any plot, nor with respect to any of the factors studied.  Population characteristics of the species are determined by several factors, including habitat quality and food distribution and abundance.  If changes occur in these factors (either artificially or naturally) then movement, abundance and population density are affected in response to such changes.  Although some results were not statistically significant, an apparent interaction was observed between habitat quality and resource availability, thereby influencing the abundance and density of A. montensis.

Variation in the home-range size of the squirrel glider (Petaurus norfolcensis)

2010 ◽  
Vol 32 (2) ◽  
pp. 183 ◽  
Author(s):  
Ross L. Goldingay ◽  
David J. Sharpe ◽  
Matt D. J. Dobson
Keyword(s):  
Home Range ◽  
Habitat Quality ◽  
New South ◽  
Home Range Size ◽  
Range Size ◽  
Home Ranges ◽  
Minimum Convex Polygon ◽  
South Wales ◽  
Squirrel Glider ◽  
Range Estimate

The home-range area of animals may vary geographically and in response to habitat quality. We investigated the size of squirrel glider (Petaurus norfolcensis) home ranges near Brisbane, Queensland, and at Tea Gardens on the central coast of New South Wales. Habitat at both sites had been partially cleared and had been subjected to grazing for several decades. Twelve gliders were tracked over an average of 3.5 months in Brisbane. The fixed kernel (FK95%) home-range estimate averaged 4.6 ± 0.7 (s.e.) ha while the minimum convex polygon (MCP100%) averaged 6.7 ± 1.5 ha. Six gliders were tracked over 1 month at Tea Gardens. The FK95% home-range estimate averaged 14.8 ± 2.4 ha while the MCP100% averaged 13.3 ± 3.1 ha. The Tea Gardens values are derived from relatively short periods and are likely to underestimate the areas used. This study demonstrates that home-range size can vary substantially in the squirrel glider. This has implications for understanding how this species responds to variation in habitat quality and highlights the need for site-specific studies to inform aspects of management.

scholarly journals New insights on the rarity of the vulnerable Cinereous Warbling-finch (Aves, Emberizidae) based on density, home range, and habitat selection

2014 ◽  
Vol 74 (4) ◽  
pp. 795-802
Author(s):  
F Marques-Santos ◽  
U Wischhoff ◽  
M Rodrigues
Keyword(s):  
Habitat Selection ◽  
Home Range ◽  
Habitat Degradation ◽  
Habitat Modification ◽  
Home Ranges ◽  
Minimum Convex Polygon ◽  
Natural Habitats ◽  
Grassland Bird ◽  
Cerrado Vegetation ◽  
Selection Of

The Cinereous Warbling-finch Poospiza cinerea (Emberizidae) is a Neotropical grassland bird considered rare, with population declining due to habitat loss and classified as vulnerable. However, the species conspicuously remains in several degraded areas, suggesting that it may be favored by these environments. Studies which focus on this species were inexistent until 2012, making questionable any statement about its threaten status. Here we analyzed population density, home range, and habitat selection of two groups of P. cinerea at independent sites that differ in human impact levels. Density was estimated by counting and mapping birds. Kernel density and minimum convex polygon were used to estimate home ranges. Habitat selection was inferred from use and availability of every habitat identified within the home range boundaries. One group positively selected urban tree vegetation, despite the availability of natural habitats in its home range. Based on a review on the literature and our findings, we assume that it is unlikely that P. cinerea is rare owing to habitat degradation, as previously thought. Nevertheless, this species was always recorded around native Cerrado vegetation and thus habitat modification may still threaten this species at some level. It is suggested that this species might be a woodland edge species, but future studies are necessary to confirm this assumption.

scholarly journals Home range and habitat use by pacas in a montane tropical forest in Bolivia

2017 ◽  
Vol 47 (3) ◽  
pp. 227-236 ◽  
Author(s):  
Camila BENAVIDES ◽  
Alejandro ARCE ◽  
Luis F. PACHECO
Keyword(s):  
Home Range ◽  
Habitat Use ◽  
Secondary Forest ◽  
Agroforestry Systems ◽  
Minimum Convex Polygon ◽  
Forest Patches ◽  
La Paz ◽  
Agricultural Community ◽  
The Mean ◽  
Montane Tropical Forest

ABSTRACT We studied the home range and habitat use of paca (Cuniculus paca) in a rural agricultural community in the Alto Beni region, in La Paz department, Bolivia, where game meat is the main source of protein for a large portion of local inhabitants. We captured and radio collared five individual paca (4 females and 1 male), which were followed for six months in 2012 to estimate home range of the individuals and assess their habitat use and selection. The total mean home range (95% Minimum Convex Polygon) was 2.26 ha (SD = 0.80), and ranged from 1.5 to 2.96 ha. The mean female home range (2.04 ha) was smaller than the male´s (2.95 ha). Pacas used two (crops and fallows) of the three available habitats (secondary forest patches), and appeared to positively select crops over the other two. The importance of crops may be linked to the type of agriculture conducted in the area (i.e. mainly cacao in agroforestry systems), which may offer more food and shelter for pacas. Given that, the importance of habitats may change seasonally; this topic should be examined in future studies. Our results suggest that agroforestry systems may be important for the species since they offer a variety of food resources throughout the year.

Determinants of home range size and spatial overlap of Gracilinanus agilis (Mammalia: Didelphidae) in central-western Brazil

Mammalia ◽  
2018 ◽  
Vol 82 (4) ◽  
pp. 328-337
Author(s):  
Patrícia Sayuri Shibuya ◽  
Geruza Leal Melo ◽  
Nilton Carlos Cáceres
Keyword(s):  
Sexual Dimorphism ◽  
Home Range ◽  
Food Availability ◽  
Convex Polygon ◽  
Food Resource ◽  
Home Range Size ◽  
Territorial Behavior ◽  
Important Predictor ◽  
Minimum Convex Polygon ◽  
Males And Females

Abstract The use of space in mammals may vary according to sexual dimorphism, mating system and territorial behavior in order to ensure optimization of the reproductive success of each sex and the interactions with other species. In the present study, the determinants of home range (HR) size of males and females of Gracilinanus agilis (Burmeister 1854) were evaluated in a savanna remnant in central-western Brazil. We used live traps and capture-mark-recapture to estimate HR size. Using the method of minimum convex polygon, we estimated the HR of 24 individuals. The species showed sexual dimorphism, with males showing larger body size. The HR estimated was 0.38±0.41 ha and the highest estimated HR was for a male, with 2.08 ha. Females’ HR sizes varied according to body mass, food availability and number of captures. The more important predictor for males was the number of females found within their HRs. The overlapping areas between pairs of males were larger than those between pairs of females, suggesting that females have territorial behavior as they had mostly exclusive HRs. Considering that food availability was an important predictor for female HR size, we hypothesize that the territorial behavior in females is related to food resource.

Home Range Size and Seasonal Variation in Habitat Use of Aye-Ayes (Daubentonia madagascariensis) in Torotorofotsy, Madagascar

2020 ◽  
Vol 91 (6) ◽  
pp. 558-574
Author(s):  
Timothy M. Sefczek ◽  
Ryan A. Hagenson ◽  
Doménico Roger Randimbiharinirina ◽  
Jeannin Nicolas Rakotondrazandry ◽  
Edward E. Louis
Keyword(s):  
Home Range ◽  
Habitat Use ◽  
Resource Availability ◽  
Brownian Bridge ◽  
Minimum Convex Polygon ◽  
Seasonal Differences ◽  
Climatic Fluctuations ◽  
Daubentonia Madagascariensis ◽  
Undisturbed Forest ◽  
Seasonal Shifts

Madagascar’s dramatic climatic fluctuations mean most lemurs adjust behaviors seasonally as resource availability fluctuates. Many lemurs will adopt one of two strategies, a resource maximizer or an area minimizer, when adjusting to seasonal shifts in resource availability. However, it is unknown if and how aye-aye (<i>Daubentonia madagascariensis</i>) ranging behavior is influenced by seasonality. We explored whether habitat use changed seasonally. We followed two aye-ayes, an adult male and an adult female, in the undisturbed forest of Torotorofotsy, Madagascar, from April 2012 to December 2017. We used instantaneous focal-animal sampling to collect behavioral data every 5 min and GPS locations every 20 min. We used the minimum convex polygon (MCP) to determine overall home range, and the Brownian bridge movement model (BBMM) to estimate overall and seasonal home range of the female aye-aye from November 2014 to October 2017. We used Wilcoxon signed-rank tests to determine whether there were significant differences in home range sizes between seasons across years and to examine whether there were seasonal differences in height of invertebrate foraging, generalized linear models to assess seasonal differences in travel rates and nesting locations, and χ<sup>2</sup> tests to determine whether there were differences in forest strata use when foraging on invertebrates. The male’s MCP home range was 2,586 ha, and the female’s MCP home range was 765 ha. The seasonal BBMM for the female varied between 443.6 and 1,010.0 ha, though infant rearing appears to have influenced these values. There were no significant differences in seasonal home range, travel rates, nesting locations, or height of invertebrate feeding. However, canopy level invertebrate foraging occurred more often than understory or ground levels. It appears aye-ayes in this undisturbed forest were not influenced by seasonal shifts and had larger home ranges than any previously reported. These findings may indicate that aye-ayes in an undisturbed forest are resource maximizers, closely linked to invertebrate assemblages.

Resource availability drives variation in a marsupial glider’s home‐range size

2021 ◽  
Author(s):  
A. M. Stobo‐Wilson ◽  
T. Cremona ◽  
B. P. Murphy ◽  
S. M. Carthew
Keyword(s):  
Home Range ◽  
Resource Availability ◽  
Home Range Size ◽  
Range Size

Field Observations on the Common Striped Possum (Dactylopsila Trivirgata) in North Queensland.

1996 ◽  
Vol 23 (6) ◽  
pp. 755 ◽  
Author(s):  
KA Handasyde ◽  
RW Martin
Keyword(s):  
Body Weight ◽  
Home Range ◽  
Foraging Behaviour ◽  
Male Body ◽  
Radio Tracking ◽  
Minimum Convex Polygon ◽  
Far North ◽  
Large Trees ◽  
The Common ◽  
Primary Habitat

Habitat utilisation and foraging behaviour by the common striped possum (Dactylopsila trivirgata) was investigated by means of spotlighting and radio-tracking at Shiptons Flat, far north Queensland. Vine forest was the primary habitat of D. trivirgata; however, animals were also observed in open eucalypt (Eucalyptus tereticornis) woodland. Information collected on foraging behaviour suggests that D. trivirgata are generalist insectivores consuming some fruit and other foodstuffs, such as honey. Radio-tracking data were used to calculate the home-range areas of two subadult males. The home range of the smaller male (body weight 290 g) was 5.2 ha (by the 95% harmonic mean (HM) method) or 6.5 ha (by the minimum convex polygon (MCP) method), and that of the larger male (body weight 415 g) was 21.2 ha (95% HM) or 21.3 ha (MCP). Large trees with hollows, which are utilized for denning, appear to be an important feature of the habitat for this species. D. trivirgata exhibits a pronounced degree of sociality and may breed seasonally. Observations suggest that amethystine pythons (Morelia amethistina) may be major predators of D. trivirgata at Shiptons Flat.

Ecological Correlates of Fecal Corticosterone Metabolites in Female Greater Sage-Grouse (Centrococercus urophasianus)

2021 ◽  
Author(s):  
Jordan Clark Rabon ◽  
Cassandra M. V. Nuñez ◽  
Peter Coates ◽  
Mark Ricca ◽  
Tracey N. Johnson
Keyword(s):  
Home Range ◽  
Stress Responses ◽  
Habitat Degradation ◽  
Home Range Size ◽  
Range Size ◽  
Home Ranges ◽  
Remotely Sensed Data ◽  
Sage Grouse ◽  
Ecological Conditions ◽  
Annual Grasses

Measurement of physiological responses can reveal effects of ecological conditions on an animal and correlate with demographic parameters. Ecological conditions for many animal species have deteriorated as a function of invasive plants and habitat fragmentation. Expansion of juniper (Juniperus spp.) trees and invasion of annual grasses into sagebrush (Artemisia spp.) ecosystems have contributed to habitat degradation for Greater Sage-Grouse (Centrococercus urophasianus (Bonaparte, 1827); hereafter, “Sage-Grouse”), a species of conservation concern throughout its range. We evaluated relationships between habitat use in a landscape modified by juniper expansion and annual grasses and corticosterone metabolite levels (stress responses) in feces (FCORTm) of female Sage-Grouse. We used remotely sensed data to estimate vegetation cover within hens’ home ranges and accounted for factors that influence FCORTm in other vertebrates, such as age and weather. We collected 36 fecal samples from 22 radio-collared hens during the brood-rearing season (24 May–26 July) in southwestern Idaho 2017–18. Concentrations of corticosterone increased with home range size but decreased with reproductive effort and temperature. The importance of home range size suggests that maintaining or improving habitats that promote smaller home ranges would likely facilitate a lower stress response by hens, which should benefit Sage-Grouse survival and reproduction.

Observations on the behaviour and ecology of the Common Wombat Vombatus ursinus in northeast Tasmania.

1993 ◽  
Vol 16 (1) ◽  
pp. 1
Author(s):  
R.J. Taylor
Keyword(s):  
Home Range ◽  
Agricultural Land ◽  
Social Role ◽  
Mating Behaviour ◽  
Scent Marking ◽  
Average Density ◽  
Home Ranges ◽  
Faecal Pellets ◽  
Common Wombat ◽  
The Common

Aspects of the behaviour and ecology of Vombatus ursinus were studied in largely cleared agricultural land in a coastal area in northeast Tasmania. The average density of V. ursinus was 20 individuals.km-2 over the whole study area but around 60.km-2 in an intensively studied section. Burrows were concentrated in areas of sandy soil where a dense cover of native vegetation had been maintained. Only short, shallow burrows were present in areas of dolerite, probably because of the difficulty of digging. Home-ranges of different individuals overlapped. Wombats were not active continually through the night and varied in time of emergence from their burrow and the time spent above ground. Often more than one burrow was used on the same night, with more than one individual making use of a burrow, but usually not at the same time. Disputes over the use of burrows occurred. Individuals frequently sniffed around burrows and investigated for the presence of occupants. Males may use this as a strategy for finding females in oestrus. Mating behaviour was observed once. Wombats are solitary and actively avoid the presence of others. Odour in faecal pellets and from scent marking probably plays an important social role by providing information on the individuals sharing a home-range and the occurrence of strangers. Dominant animals may be intolerant of the presence of certain individuals within their home-range.

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