HABITAT UTILIZATION BY THE TEXAS HORNED LIZARD (PHRYNOSOMA CORNUTUM) FROM TWO SITES IN CENTRAL TEXAS

The Texas Horned Lizard (Phrynosoma cornutum) is found in a variety of habitats. Although several studies have been conducted on habitat use by this species, none have been performed in central Texas, a more mesic habitat than most of those previously studied. This area is of special interest because horned lizard populations have been experiencing sharp declines in central Texas over the last approximately 50 years. We collected habitat data at two sites in central Texas, Camp Bowie and Blue Mountain Peak Ranch. Microhabitat data included canopy cover and ground cover from digitized photographs of Daubenmire quadrats; macrohabitat variables included vegetation height and length, cactus height, soil penetrability, woody plant species richness, tree density, tree diameter at breast height (DBH), and density of ant mounds collected along 100-m by 2-m transects. Similar patterns of habitat use were observed between the two sites. At Blue Mountain Peak Ranch, lizards appeared to be located in areas with a diversity of ground cover types, as observed in previous studies. At Camp Bowie, vegetation encroachment limited lizards in some areas to the use of roads and road margins. Implementation of prescribed burns or other vegetation management could create the preferred ground cover mosaic at such sites.

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Fine-scale habitat use by the southern emu-wren (Stipiturus malachurus)

Wildlife Research ◽

10.1071/wr05040 ◽

2006 ◽

Vol 33 (2) ◽

pp. 137 ◽

Cited By ~ 4

Author(s):

Grainne S. Maguire

Keyword(s):

Habitat Use ◽

Plant Species ◽

Habitat Structure ◽

Canopy Cover ◽

Ground Level ◽

Fine Scale ◽

Vegetation Height ◽

Vertical Density ◽

Foliage Density ◽

Floristic Characteristics

Fine-scale variation in habitat structure and composition is likely to influence habitat use by avian species with limited flight capabilities. I investigated proportional use of available habitat and microhabitat by the southern emu-wren (Stipiturus malachurus), a threatened, flight-limited passerine, at three sites in Victoria, in relation to vegetation structure and composition. Emu-wrens appeared to discriminate between habitats with regard to structural rather than floristic characteristics. Habitats with dense vertical foliage of shrubs, grasses and sedges/rushes between ground level and 100 cm, and dense horizontal cover of medium to tall shrubs, were used most frequently. However, when availability of habitat was taken into account, habitat use was negatively correlated with the vertical density of low shrub foliage and species richness. Within habitats, emu-wrens more frequently used plant species that had a dense canopy cover (26 ± 2% of total cover, crown diameter 93 ± 5 cm), high foliage density between 50 and 100 cm, and average heights of ~1 m. Plant species in which the birds nested comprised ~14% of total canopy cover and were densest between ground level and 50 cm. Canopy cover, vegetation height and vertical foliage density were consistently important variables correlated with emu-wren habitat use at multiple fine-scales. This study provides valuable information for conservation management of the species; in particular, the restoration of degraded habitats.

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Prey, management and landscape requirements of an endangered population of the Woodlark Lullula arborea in Southwest Germany

Journal of Ornithology ◽

10.1007/s10336-021-01862-4 ◽

2021 ◽

Author(s):

Verena Rösch ◽

Pascal Aloisio ◽

Martin H. Entling

Keyword(s):

Food Resource ◽

Bird Species ◽

Ground Cover ◽

Main Food ◽

Vegetation Height ◽

Endangered Population ◽

Rhine Valley ◽

Territory Selection ◽

Main Food Source ◽

Upper Rhine

AbstractVineyards can be valuable habitats for biodiversity conservation. For example, in Rhineland-Palatinate (Germany) over a third of the state’s critically endangered Woodlark (Lullula arborea) population breeds in vineyards along the western margin of the Upper Rhine Valley. We here aim to elucidate how local ground cover management, food availability and the proximity to settlements affect territory selection by this bird species in the region. As climate, site conditions and management differ greatly from more continental or Mediterranean wine-growing areas, conditions for Woodlark conservation may differ as well.We compared 26 Woodlark territories in vineyards with 26 nearby reference areas from which Woodlarks were absent. We recorded vineyard ground cover in the inter-rows (% cover) as well as vegetation height and composition (forbs vs. grasses). Arthropods were sampled using pitfall traps, since they are the main food resource of Woodlarks during the breeding season. In addition, the distance to built-up areas was measured. The vegetation in Woodlark territories was shorter (mean 14.2 vs. 19.6 cm) and more dominated by forbs (39% vs. 27% cover) than in absence areas. The vegetation cover in the inter-rows had no effect on Woodlark territory presence or absence. Woodlarks also favoured areas with a higher abundance of arthropods (mean abundance 69.1 vs. 57.5) and a greater distance to built-up areas (mean distance 554 vs. 373 m). We conclude that to promote the Woodlark in wine-growing areas, short, forb-rich swards should be created, facilitating arthropod detectability. This is likely to require low levels of nitrogen fertilization since fertilizers favour tall-growing grasses that outcompete forbs. Pesticide applications should be kept at a minimum to enhance arthropods as the main food source for Woodlarks and their chicks. In addition, the expansion of settlements into breeding areas of Woodlarks should be avoided.

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Effects of logging and fire on small mammals in Mumbulla State Forest, near Bega, New South Wales

Wildlife Research ◽

10.1071/wr9870163 ◽

1987 ◽

Vol 14 (2) ◽

pp. 163 ◽

Cited By ~ 33

Author(s):

D. Lunney ◽

B. Cullis ◽

P. Eby

Keyword(s):

Small Mammals ◽

New South ◽

New South Wales ◽

Canopy Cover ◽

Ground Cover ◽

First Year ◽

Severe Effect ◽

South Wales ◽

Antechinus Stuartii ◽

Rattus Fuscipes

This study of the effects of logging on small mammals in Mumbulla State Forest on the south coast of New South Wales included the effects of a fire in November 1980 and a drought throughout the study period from June 1980 to June 1983. Rattus fuscipes was sensitive to change: logging had a significant impact on its numbers, response to ground cover, and recapture rate; fire had a more severe effect, and drought retarded the post-fire recovery of the population. The three species of dasyurid marsupials differed markedly in their response to ground cover, canopy cover, logging and fire. Antechinus stuartii was distributed evenly through all habitats and was not affected by logging, but fire had an immediate and adverse effect which was sustained by the intense drought. A. swainsonii markedly preferred the regenerating forest, and was not seen again after the fire, the failure of the population being attributed to its dependence on dense ground cover. Sminthopsis leucopus was found in low numbers, appeared to prefer forest with sparse ground cover, and showed no immediate response to logging or fire; its disappearance by the third year post-fire suggests that regenerating forest is inimical to the survival of this species. Mus musculus showed no response to logging. In the first year following the fire its numbers were still very low, but in the next year there was a short-lived plague which coincided with the only respite in the 3-year drought and, importantly, occurred in the intensely burnt parts of the forest. The options for managing this forest for the conservation of small mammals include minimising fire, retaining unlogged forest, extending the time over which alternate coupes are logged and minimising disturbance from heavy machinery.

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Habitat use by the endangered Karner blue butterfly in oak woodlands: the influence of canopy cover

Biological Conservation ◽

10.1016/s0006-3207(97)00165-1 ◽

1998 ◽

Vol 85 (1-2) ◽

pp. 47-53 ◽

Cited By ~ 56

Author(s):

Ralph Grundel ◽

Noel B. Pavlovic ◽

Christina L. Sulzman

Keyword(s):

Habitat Use ◽

Canopy Cover ◽

Oak Woodlands ◽

Karner Blue Butterfly ◽

Blue Butterfly

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Edge-habitat Use by Northwestern Gartersnakes (Thamnophis ordinoides) in Saanich, British Columbia

The Canadian Field-Naturalist ◽

10.22621/cfn.v131i1.1751 ◽

2017 ◽

Vol 131 (1) ◽

pp. 37-45

Author(s):

Graham P. Dixon-MacCallum ◽

Katie A.H. Bell ◽

Patrick T. Gregory

Keyword(s):

British Columbia ◽

Habitat Use ◽

Survey Methods ◽

Canopy Cover ◽

Habitat Requirements ◽

Habitat Features ◽

Edge Habitat ◽

Initial Assumption ◽

Important Habitat ◽

Habitat Variables

Understanding habitat requirements of species is fundamental for their conservation and urban parks can provide key habitat for species in otherwise disturbed settings. Northwestern Gartersnakes (Thamnophis ordinoides) are common in parks in Saanich, British Columbia, but their specific habitat requirements are poorly understood. Based on previous studies and thermoregulatory needs of snakes, we predicted that edges, particularly field margins, would be heavily used by active snakes. We therefore used surveys that focused on edges to find snakes and measured edge-habitat use by comparing habitat variables at locations where snakes were found to the same variables at nearby random locations. Habitat variables included composition and structure of vegetation, substrate temperature, aspect, and slope. Overall, litter depth, canopy cover, a lack of bare ground and woody vegetation were the most important habitat variables for determining where snakes were found. our results provide a preliminary assessment to improve our understanding of habitat use for this species. The abundance of snakes found while surveying edges supports our initial assumption that edges are important habitat features but more work is required using multiple survey methods to further test this hypothesis.

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Accuracy Assessment of GEDI Terrain Elevation and Canopy Height Estimates in European Temperate Forests: Influence of Environmental and Acquisition Parameters

Remote Sensing ◽

10.3390/rs12233948 ◽

2020 ◽

Vol 12 (23) ◽

pp. 3948

Author(s):

Markus Adam ◽

Mikhail Urbazaev ◽

Clémence Dubois ◽

Christiane Schmullius

Keyword(s):

Laser Scanning ◽

Temperate Forests ◽

Accuracy Assessment ◽

Canopy Cover ◽

Global Scale ◽

Canopy Height ◽

Ecosystem Dynamics ◽

Vegetation Height ◽

Height Estimates ◽

Terrain Elevation

Lidar remote sensing has proven to be a powerful tool for estimating ground elevation, canopy height, and additional vegetation parameters, which in turn are valuable information for the investigation of ecosystems. Spaceborne lidar systems, like the Global Ecosystem Dynamics Investigation (GEDI), can deliver these height estimates on a near global scale. This paper analyzes the accuracy of the first version of GEDI ground elevation and canopy height estimates in two study areas with temperate forests in the Free State of Thuringia, central Germany. Digital terrain and canopy height models derived from airborne laser scanning data are used as reference heights. The influence of various environmental and acquisition parameters (e.g., canopy cover, terrain slope, beam type) on GEDI height metrics is assessed. The results show a consistently high accuracy of GEDI ground elevation estimates under most conditions, except for areas with steep slopes. GEDI canopy height estimates are less accurate and show a bigger influence of some of the included parameters, specifically slope, vegetation height, and beam sensitivity. A number of relatively high outliers (around 9–13% of the measurements) is present in both ground elevation and canopy height estimates, reducing the estimation precision. Still, it can be concluded that GEDI height metrics show promising results and have potential to be used as a basis for further investigations.

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The Influence of Prey Availability and Vegetation Characteristics on Scent Station Visitation Rates of Coyotes, Canis latrans, in a Heterogeneous Environment

The Canadian Field-Naturalist ◽

10.22621/cfn.v118i3.6 ◽

2004 ◽

Vol 118 (3) ◽

pp. 341 ◽

Cited By ~ 1

Author(s):

Lynda A. Randa ◽

John A. Yunger

Keyword(s):

Canis Latrans ◽

Prey Availability ◽

Canopy Cover ◽

Ground Cover ◽

Heterogeneous Environment ◽

Visitation Rates ◽

Foliage Density ◽

Grassland Habitats ◽

The Relationship ◽

Habitat Variables

We investigated the effects of local prey fluctuations and habitat variables on the scent station visitation rates of the Coyote (Canis latrans) in northern Illinois within a heterogeneous environment. Availability of small mammalian prey was assessed by monthly mark-recapture sampling and visual counts conducted along three, 192-m transects in each of seven habitats that ranged from grassland to wooded sites. Habitat metrics, which included foliage density, ground cover, and canopy cover, were also collected for the same seven habitats. Visitation rates of Coyotes were determined from scent station lines parallel to the small mammal trapping transects. A multiple regression analysis indicated that Coyote visitation rates across the study site were influenced positively by vole (Microtus spp.) abundance and negatively by canopy cover. When Coyote visitation rates were regressed on vole abundance for only the habitats in which voles occurred, the relationship was not significant. This may be attributed to the general avoidance of wooded areas by Coyotes. Coyotes did, however, respond to experimentallyinduced abundant patches of Peromyscus. These findings suggest Coyotes selectively use grassland habitats within a heterogeneous environment and may modify their use according to prey availability.

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Regional Scale Dryland Vegetation Classification with an Integrated Lidar-Hyperspectral Approach

Remote Sensing ◽

10.3390/rs11182141 ◽

2019 ◽

Vol 11 (18) ◽

pp. 2141 ◽

Cited By ~ 1

Author(s):

Hamid Dashti ◽

Andrew Poley ◽

Nancy F. Glenn ◽

Nayani Ilangakoon ◽

Lucas Spaete ◽

...

Keyword(s):

Regional Scale ◽

Imaging Spectroscopy ◽

Canopy Structure ◽

Canopy Cover ◽

Vegetation Classification ◽

Large Contribution ◽

Spectral Angle Mapper ◽

Vegetation Height ◽

Sparse Canopy ◽

Spectral Mixture

The sparse canopy cover and large contribution of bright background soil, along with the heterogeneous vegetation types in close proximity, are common challenges for mapping dryland vegetation with remote sensing. Consequently, the results of a single classification algorithm or one type of sensor to characterize dryland vegetation typically show low accuracy and lack robustness. In our study, we improved classification accuracy in a semi-arid ecosystem based on the use of vegetation optical (hyperspectral) and structural (lidar) information combined with the environmental characteristics of the landscape. To accomplish this goal, we used both spectral angle mapper (SAM) and multiple endmember spectral mixture analysis (MESMA) for optical vegetation classification. Lidar-derived maximum vegetation height and delineated riparian zones were then used to modify the optical classification. Incorporating the lidar information into the classification scheme increased the overall accuracy from 60% to 89%. Canopy structure can have a strong influence on spectral variability and the lidar provided complementary information for SAM’s sensitivity to shape but not magnitude of the spectra. Similar approaches to map large regions of drylands with low uncertainty may be readily implemented with unmixing algorithms applied to upcoming space-based imaging spectroscopy and lidar. This study advances our understanding of the nuances associated with mapping xeric and mesic regions, and highlights the importance of incorporating complementary algorithms and sensors to accurately characterize the heterogeneity of dryland ecosystems.

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Integumental water movement and rate of water ingestion during rain harvesting in the Texas horned lizard, Phrynosoma cornutum

Amphibia-Reptilia ◽

10.1163/156853804322992814 ◽

2004 ◽

Vol 25 (1) ◽

pp. 29-39 ◽

Cited By ~ 18

Author(s):

Wade Sherbrooke

Keyword(s):

Capillary Flow ◽

Water Movement ◽

Flow System ◽

Water Delivery ◽

Phrynosoma Cornutum ◽

Water Ingestion ◽

Jaw Opening ◽

Texas Horned Lizard ◽

The Mean ◽

Opening And Closing

AbstractCapture of rainfall on skin surfaces and its transport via capillary channels between scales to the mouth for drinking has been documented in a few agamid (Moloch and Phrynocephalus) and iguanid (Phrynosoma spp.) lizards. Associated behaviors include a postural stance and jaw motions. This experimental study documents that rate of jaw opening and closing cycles is positively correlated with rate of water delivery to lizards' backs and to gain in mass of lizards attributable to drinking. The mean mass of water that can be held by the interscalar, capillary-flow system is correlated with body size, smaller lizards holding a larger percentage of their body mass in the rain-harvesting system. Ingestion mechanisms for water flow from the integumental channels to the mouth surfaces for drinking are discussed, with note being made of the possible roles of a fold of skin at the jaw angle (at the postlabial scales) and tongue actions. Recent hatchlings exhibit rain-harvesting behavior, suggesting its innate nature.

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