Effects of forest degradation on abundance and microhabitat selection by ground dwelling Chaco lizards

2009 ◽  
Vol 30 (2) ◽  
pp. 265-271 ◽  
Author(s):  
Nicolás Pelegrin ◽  
Enrique Hugo Bucher ◽  
Ada Lilian Echevarría ◽  
José María Chani
Keyword(s):  
Habitat Suitability ◽  
Vegetation Structure ◽  
Forest Degradation ◽  
Microhabitat Use ◽  
Microhabitat Selection ◽  
Bare Ground ◽  
Thermal Requirements ◽  
Plastic Process ◽  
Disturbed Forest ◽  
Forest Conditions

AbstractHuman-induced degradation of Chaco forests has led to a mosaic of habitats with different forest conditions, offering different habitat suitability characteristics to the native fauna. Abundance and microhabitat use of Teius teyou, Liolaemus chacoensis, Cnemidophorus ocellifer, and Tropidurus etheridgei were analyzed in the western Chaco forest of Argentina. A mature forest that has remained undisturbed for the last 30 years (Los Colorados Biological Station, LC) and a highly disturbed forest (Campo Grande, CG) were compared through diurnal visual encounter surveys along 74 1-km transects. Lizards were assigned to the microhabitat category according to the site where they were first observed (bare ground, litter/grass/herbs, shrubs or trees). T. teyou preferred bare ground in LC, avoiding litter/grass/herbs and using shrubs according to availability, whereas in CG the species preferred shrubs, avoiding bare ground. C. ocellifer used microhabitats according to their availability in LC, whereas in CG, this species preferred shrubs and avoided the remaining microhabitats. L. chacoensis preferred bare ground in LC, using litter/grass/herbs and shrubs according to availability. In CG, the species used bare ground according to availability, preferred shrubs, and avoided litter/grass/herbs. T. etheridgei preferred bare ground in LC, avoiding litter/grass/herbs, and using shrubs according to availability, whereas in CG both bare ground and shrubs were preferred, and litter/grass/herbs was avoided. Our results suggest that microhabitat selection by lizards in the Chaco is a plastic process influenced by vegetation structure, and probably regulated by lizards' thermal requirements.

Differences in microhabitat selection patterns between a remnant and constructed landscape following management intervention

2017 ◽  
Vol 44 (3) ◽  
pp. 248 ◽  
Author(s):  
Jose W. Valdez ◽  
Kaya Klop-Toker ◽  
Michelle P. Stockwell ◽  
Loren Fardell ◽  
Simon Clulow ◽  
...  
Keyword(s):  
Aquatic Vegetation ◽  
Management Strategies ◽  
Probability Of Detection ◽  
Microhabitat Use ◽  
Microhabitat Selection ◽  
Habitat Creation ◽  
Litoria Aurea ◽  
Use Of Resources ◽  
Detection Probabilities ◽  
Future Management

Context Achieving successful conservation outcomes in habitat creation and reintroductions requires an understanding of how species use their habitat and respond to these interventions. However, few initiatives directly compare microhabitat selection between remnant and managed habitats to measure effectiveness and evaluate outcomes. Probability of detection is also rarely included in studies on microhabitat use, which may lead to erroneous conclusions if detectability varies between variables. Methods In this study, we used the endangered green and golden bell frog (Litoria aurea) to compare differences in microhabitat-use patterns in both a remnant and a constructed habitat. A detectability study was also conducted to determine detection probabilities among microhabitats. Key results Aquatic vegetation was used more than expected in both the remnant and constructed habitats, and rock piles were utilised less than expected in the constructed habitat, despite their recommendation in most habitat templates. We found that detection probabilities altered the outcomes of abundance estimates for nearly all the measured microhabitat variables. Conclusions Future management for this species should focus on providing high proportions of aquatic vegetation. Furthermore, although rock piles have been utilised greatly in past L. aurea habitat creation, placing large rocks on a managed site is expensive and time consuming. Future management initiatives may need to focus on providing smaller proportion of rocks, which would be a more appropriate use of resources. Implications With conservation management projects increasing over the next few decades, understanding habitat use before implementing strategies should be a priority as it will provide important insights and inform decision-making for optimum habitat creation and restoration. Furthermore, accounting for detectability in microhabitat use studies is essential to avoid wrong conclusions that may negatively affect the success of ecological management strategies.

scholarly journals Summer microhabitat use and overlap by the invasive Round Goby (Neogobius melanostomus) and native darters in the Trent River (Ontario, Canada)

2019 ◽  
pp. 23
Author(s):  
Scott M. Reid
Keyword(s):  
Habitat Suitability ◽  
Native Species ◽  
Round Goby ◽  
High Water ◽  
Neogobius Melanostomus ◽  
Microhabitat Use ◽  
Intermediate Water ◽  
Habitat Differences ◽  
Species Declines ◽  
Water Depths

Understanding the impacts of the invasive Round Goby (Neogobius melanostomus) is important for North American native fish conservation. One proposed mechanism for native species declines is competition for habitat. In this study, summer habitat use by Round Goby and Channel Darter (Percina copelandi) and Logperch (P. caprodes) was studied in the Trent River (Canada). Spot-electrofishing and systematic habitat sampling were used to measure habitat availability and use. Suitability for all species varied across the range of habitat conditions. At Glen Ross, habitat suitability for Channel Darter and Round Goby was highest at intermediate water depths (0.2–0.6 m), lowest at high water velocities (> 1.0 ms−1) and increased with greater amounts of gravel and cobble. There were no significance habitat differences between capture locations of the two species. At Meyer's Reach, Logperch and Round Goby habitat suitability was highest at intermediate water depths (0.4–0.6 m) and where gravel and cobble were abundant. The relationship between suitability and water velocity differed between species, with moderate velocities less suitable for Round Goby. The amount of boulder and bedrock at capture locations of each species differed. Results indicate that competition for habitat with Round Goby will vary among darter species.

The Ecology of Small Mammals in Northeastern Tasmania .1. Rattus-Lutreolus-Velutinus

1987 ◽  
Vol 14 (4) ◽  
pp. 415 ◽  
Author(s):  
TW Norton
Keyword(s):  
Vegetation Structure ◽  
Leaf Tissue ◽  
Environmental Parameters ◽  
Microhabitat Selection ◽  
Sexually Active ◽  
Pregnant Females ◽  
North Eastern ◽  
Sclerophyll Forest ◽  
Lactating Females ◽  
Similar Body

Aspects of the ecology of Rattus lutreolus velutinus (Thomas) were studied in dry sclerophyll forest, buttongrass and heathland communities in north-eastern Tasmania. In each habitat environmental parameters which might influence the species' microhabitat selection (e.g, soil moisture, vegetation structure and floristics) and diet (e.g. monocotyledon food), were assessed. R. I, velutinus began to breed during late August. Sexually active males were captured between September and February, inclusive. Pregnant females were captured between September and November, and the number of lactating females peaked during November in all habitats. Juveniles were captured between December and February. R. I. velutinus was predominantly herbivorous, preferring stem and leaf tissue but also eating seeds, insects, roots and fungus. Captures of rats were positively correlated with vegetation cover less than 50 cm high and with a monocotyledonous food index. Population density was substantially higher in heathland than in buttongrass and dry sclerophyll forest. Animals had similar body condition in each habitat.

Patterns and scale of habitat use in two temperate-zone, small mammal faunas

1984 ◽  
Vol 62 (8) ◽  
pp. 1540-1547 ◽  
Author(s):  
Douglas W. Morris
Keyword(s):  
Habitat Selection ◽  
Small Mammals ◽  
Species Distribution ◽  
Small Mammal ◽  
Habitat Preference ◽  
Species Interactions ◽  
Microhabitat Use ◽  
Microhabitat Selection ◽  
Extinction Probabilities ◽  
Mammal Faunas

Small mammals were livetrapped and habitat quantified in replicates of six macrohabitats in Alberta and in temporal replicates of four macrohabitats in Ontario, Canada. Similar patterns emerged in both locations. The relative abundances of small mammals depended upon macrohabitat; within macrohabitats, species differed significantly in microhabitat use. The patterns were dynamic and probably the result of habitat preference instead of species interactions. Macrohabitat differences may in part be outcomes of microhabitat selection, but are unlikely to be completely understood without superimposing colonization and extinction probabilities on habitat selection models. Field biologists must recognize both scales of habitat to interpret patterns of species distribution.

scholarly journals Application of the physical habitat simulation for fish species to assess environmental flows in an Atlantic Forest Stream in South-eastern Brazil

2015 ◽  
Vol 13 (4) ◽  
pp. 685-698 ◽  
Author(s):  
Marcus Rodrigues da Costa ◽  
Tailan Moretti Mattos ◽  
Victor Hugo Fernandes ◽  
Francisco Martínez-Capel ◽  
Rafael Muñoz-Mas ◽  
...  
Keyword(s):  
Atlantic Forest ◽  
Fish Species ◽  
Habitat Suitability ◽  
Environmental Flows ◽  
Southeastern Brazil ◽  
Microhabitat Use ◽  
Physical Habitat ◽  
Forest Stream ◽  
Habitat Simulation ◽  
Target Fish

ABSTRACT The physical habitat simulation sub-routine of the Instream Flow Incremental Methodology (IFIM) uses hydraulic modeling and suitability indices of target fish species to predict how differences in-stream flows affect the microhabitat occupation by fish species. This habitat modelling approach was adopted to assess the ecological effects of running flows on three neotropical fish species of different orders (Bryconamericus ornaticeps , Ancistrus multispinis and Geophagus brasiliensis ).The study encompassed two reaches of an Atlantic Forest stream in Southeastern Brazil where topographic and hydraulic (depth, velocity and type of substrate) characteristics were measured to implement one-dimensional hydraulic simulation. Sub aquatic observation of fish was performed to collect data on microhabitat use and these data were used to develop habitat suitability curves that were used in the habitat simulation to obtain the habitat suitability index (HSI) and weighted usable area (WUA) versus flow curves. Upon these curves minimum and optimum environmental flows for the target fish species were proposed. Bryconamericus ornaticeps and A. multispinis selected microhabitats around 0.6 m depth, whereas G. brasiliensis showed a wider suitable range (0.35-0.9 m). All the three species were mainly observed in microhabitat with low flow velocity (0.1 m/s). Bryconamericus ornaticeps selected more frequently coarse substrate (e.g. boulders) but it appeared also over sandy substrate, whereas A. multispinis and G. brasiliensis selected preferably boulders. The range of 0.65-0.85 m3/s was found as the optimum to meet the needs of the three fish species. Our results agree with the necessary objective information to perform grounded management actions in the frame of a management program aiming at ecosystem conservation. Thereby it can be considered a successful pilot study in environmental flow assessment in an Atlantic Forest stream of Brazil.

Effects of fire, food availability and vegetation on the distribution of the rodent Bolomys lasiurus in an Amazonian savanna

2004 ◽  
Vol 20 (2) ◽  
pp. 183-187 ◽  
Author(s):  
Viviane Maria Guedes Layme ◽  
Albertina Pimentel Lima ◽  
William Ernest Magnusson
Keyword(s):  
Spatial Variation ◽  
Food Availability ◽  
Significant Relationship ◽  
Habitat Suitability ◽  
Vegetation Cover ◽  
Vegetation Structure ◽  
Short Term ◽  
Tall Grass ◽  
Insect Abundance ◽  
Habitat Suitability Models

We investigated the relative influences of vegetation cover, invertebrate biomass as an index of food availability and the short-term effects of fires on the spatial variation in densities of the rodent Bolomys lasiurus in an Amazonian savanna. Densities were evaluated in 31 plots of 4 ha distributed over an area of approximately 10×10 km. The cover of the tall grass (Trachypogon plumosus), short grass (Paspalum carinatum), shrubs and the extent of fire did not explain the variance in densities of Bolomys lasiurus. Food availability alone explained about 53% of the variance in B. lasiurus densities, and there was no significant relationship between insect abundance and vegetation structure. Fires had little short-term impact on the density of Bolomys lasiurus in the area we studied. As the species appears to respond principally to food availability, habitat suitability models based on easily recorded vegetation-structure variables, or the frequency of disturbance by fire, may not be effective in predicting the distribution of the species within savannas.

scholarly journals Importance of microhabitat selection by birds for the early recruitment of endangered trees in a fragmented forest

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Ning Li ◽  
Zheng Wang ◽  
Yao Cai ◽  
Lin Zhang
Keyword(s):  
Plant Regeneration ◽  
Leaf Litter ◽  
Microhabitat Use ◽  
Taxus Chinensis ◽  
Microhabitat Selection ◽  
Fragmented Forest ◽  
Litter Cover ◽  
Emergence Rate ◽  
Fragmented Forests ◽  
Early Recruitment

Abstract Background Remnant microhabitats are important for bird habitat selection and plant regeneration in the fragmented habitat. However, empirical information on the consequences of how microhabitat use by birds affects the early recruitment of plants is lacking. Methods In this study, we evaluated whether microhabitat selection by the Black Bulbul (Hypsipetes leucocephalus) (J. F. Gmelin, 1789) impacts the early recruitment of the endangered tree species, the Chinese Yew (Taxus chinensis (Pilger) Rehd), in a fragmented forest over a 4-year period (2011–2012, 2018–2019). Results Our results showed the main factors affecting H. leucocephalus microhabitat selection were distance to the nearest T. chinensis mature tree, herb cover and density, leaf litter cover, and vegetation type. Moreover, the results of logistic regression also highlighted the importance of elevation, distance to light gap and roads, tree cover in bird microhabitat selection. Furthermore, the seed emergence rate in microhabitats used by birds did not differ from the natural forest, which was related to five factors of bird microhabitat. The Random Forest model showed that seedling emergence rate was increased with leaf litter cover and distance to fallen dead trees, but decreased in relation to herb cover, slope, and elevation. Conclusion Our results highlight the importance of remnant microhabitats in fragmented forests for sustaining forest ecology and optimal management. The contribution of microhabitats used by birds to plant recruitment provides insights into how frugivore species contribute to plant regeneration, which should be incorporated in future conservation and management practices of fragmented forests.

scholarly journals Application of Diel Feeding Chronology to Habitat Suitability Analysis of Warmwater Stream Fishes

1992 ◽  
Vol 49 (7) ◽  
pp. 1417-1430 ◽  
Author(s):  
Thomas J. Kwak ◽  
Michael J. Wiley ◽  
Lewis L. Osborne ◽  
R. Weldon Larimore
Keyword(s):  
Common Carp ◽  
Ictalurus Punctatus ◽  
Channel Catfish ◽  
Habitat Suitability ◽  
Smallmouth Bass ◽  
Microhabitat Use ◽  
Micropterus Dolomieu ◽  
Daily Ration ◽  
Suitability Analysis ◽  
Longear Sunfish

Diel feeding chronology and daily ration were determined from stomach or foregut contents of common carp (Cyprinus carpio), golden redhorse (Moxostoma erythrurum), channel catfish (Ictalurus punctatus), smallmouth bass (Micropterus dolomieu), and longear sunfish (Lepomis megalotis) in the Vermilion River, Illinois. Feeding was highly variable among individuals, hours, and months for each species. Discontinuous feeding was detected in common carp, golden redhorse, and channel catfish. Common carp and the two centrarchid species fed with greatest intensity near sunrise and sunset; golden redhorse and channel catfish feeding was highest at night. Daily ration estimates were higher for fishes with stomachs than those for stomachless species. Microhabitats occupied by fish over the diel period were identified using nondisruptive techniques: direct observation, prepositioned electrofishing, and radiotelemetry. Microhabitat use during high-feeding periods was significantly different [Formula: see text] than that during low feeding for at least one habitat variable in each species examined. Association with cover also varied between feeding regimes. Our findings suggest that realism of instream flow assessments may be improved if habitat suitability criteria are stratified by feeding regime.

Microhabitat use, seasonal activity and diet of the snake-eyed skink (Ablepharus kitaibelii fitzingeri) in comparison with sympatric lacertids in Hungary

Biologia ◽  
2007 ◽  
Vol 62 (4) ◽  
Author(s):  
Gábor Herczeg ◽  
Tibor Kovács ◽  
Zoltán Korsós ◽  
János Török
Keyword(s):  
Thermal Inertia ◽  
Bare Soil ◽  
Stomach Content Analysis ◽  
Food Composition ◽  
Generalist Predator ◽  
Microhabitat Use ◽  
Microhabitat Selection ◽  
Seasonal Activity ◽  
Podarcis Muralis ◽  
Lacerta Viridis

AbstractMicrohabitat selection and seasonal activity of the snake-eyed skink, Ablephaus kitaibelii fitzingeri, are compared to the two lacertid lizards (Lacerta viridis and Podarcis muralis) that co-occur in many of its habitats. The food composition of A. k. fitzingeri is also described. Significant differences in microhabitat selection and seasonal activity among the three species were found. The snake-eyed skink was associated with open grasslands, and with a low level of scrub, bare soil and rock cover. The microhabitat preference of L. viridis was quite similar to that of the skink, but with a higher preference for scrub. P. muralis occurred in places with greater rock and bare soil cover, and more scrub than A. k. fitzingeri. Activity of the snake-eyed skink decreased dramatically in summer, probably because of the reduced thermal inertia originating from the extremely small size of this species, but its seasonal activity overlapped with those of the lacertids. Stomach content analysis of the snake-eyed skink suggests that it is a generalist predator of small, mainly flightless arthropod prey. Competition with juvenile lacertids and predation by adult L. viridis are conceivable for the snake-eyed skink.

scholarly journals Responding to forest degradation: altered habitat use by Dian's tarsier Tarsius dianae in Sulawesi, Indonesia

Oryx ◽  
2005 ◽  
Vol 39 (2) ◽  
pp. 189-195 ◽  
Author(s):  
Stefan Merker ◽  
Indra Yustian ◽  
Michael Mühlenberg
Keyword(s):  
Anthropogenic Disturbance ◽  
Animal Species ◽  
Forest Degradation ◽  
Home Ranges ◽  
Population Densities ◽  
Human Land Use ◽  
Path Lengths ◽  
Disturbed Forest ◽  
Central Sulawesi ◽  
Travel Distances

As most of the pristine forests of South-east Asia have been lost, the ability of its animal species to coexist with humans becomes increasingly important. Dian's tarsier Tarsius dianae, one of the smallest primates, lives in forests of central Sulawesi, Indonesia that are experiencing a dramatic increase in degradation by humans. To evaluate the effects of anthropogenic disturbance on tarsiers we used a comprehensive approach to estimate habitat suitability for these nocturnal insecthunters. On four study plots along a gradient of human land-use we determined population densities, home range sizes, nightly path lengths and group sizes of T. dianae. In total we captured 71 individuals and radio-tracked 30 of these. In more undisturbed sites, population densities were high and travel distances small. We found the smallest home ranges in slightly disturbed forest. In a heavily disturbed plantation densities were low, and ranges and nightly path lengths were large. These results show that undisturbed and slightly degraded forests are the most suitable tarsier habitats, and that focusing on different population parameters could lead to differing conclusions about the suitability of particular habitats.

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