Tree lizard distribution and mating system: the influence of habitat and food resources

1990 ◽  
Vol 68 (10) ◽  
pp. 2083-2089 ◽  
Author(s):  
Robert T. M'Closkey ◽  
Richard J. Deslippe ◽  
Christopher P. Szpak ◽  
Keith A. Baia
Keyword(s):  
Mating System ◽  
Sonoran Desert ◽  
Food Resource ◽  
Food Resources ◽  
Home Ranges ◽  
Territory Quality ◽  
Soil Hardness ◽  
Male Tree ◽  
Tree Lizards ◽  
Tree Lizard

We examined the distribution of an insectivorous iguanid lizard (Iguanidae: Urosaurus ornatus, tree lizard) in the Sonoran Desert of Arizona in 1984, 1986, and 1987. The purpose of the investigation was to examine the ecological correlates of lizard distribution and mating system. Data from 420 marked lizards which were captured 1552 times provided information on habitat-level differences in lizard numbers and characteristics of home ranges in which oviposition occurred. In addition, we evaluated the role of arthropod food resources in the distribution of female home range and in the mating status of males. In dry washes tree lizards occupied mesquite (Prosopis juliflora) trees, whereas in flatland habitat they lived in mesquite trees and other sites (dead mesquite and saguaro cactus, Carnegeia gigantea). Lizards were more abundant in dry washes than flatland habitat. The lizard mating system was variable and a greater proportion of males were polygynous in wash (33–67%) compared with flatland (7–33%) habitat. In the flatland, home ranges in which females oviposited could be distinguished from vacant sites by soil hardness, shrub cover, and the presence of wood rat (Neotoma albigula) nests. Arthropod abundance did not differ between female home ranges and nearest vacant site nor between habitats and among male territories. Therefore, food resource distribution does not appear to be a determinant of either female distribution or territory quality in male tree lizards.

scholarly journals Diet seasonality and food overlap of the fish assemblage in a pantanal pond

2008 ◽  
Vol 6 (4) ◽  
pp. 567-576 ◽  
Author(s):  
Gisele Caroline Novakowski ◽  
Norma Segatti Hahn ◽  
Rosemara Fugi
Keyword(s):  
Fish Assemblage ◽  
Food Resource ◽  
Fish Fauna ◽  
Diet Breadth ◽  
Food Resources ◽  
Dry Season ◽  
Trophic Guilds ◽  
Trophic Specialization ◽  
Mato Grosso ◽  
Mean Values

We assessed the trophic structure of the fish fauna in Sinhá Mariana pond, Mato Grosso State, from March 2000 to February 2001. The aim was to determine the feeding patterns of the fish species during the rainy and dry seasons. The diets of 26 species (1,294 stomach contents) were determined by the volumetric method. Insects and fish were the most important food resources: insects were the dominant food of 23% and 27% of the species, respectively, in the rainy and dry season, and fish was the dominant item for 31% of the species in both seasons. Cluster analysis (Euclidean Distance) identified seven trophic guilds in the rainy season (detritivores, herbivores, insectivores, lepidophages, omnivores, piscivores and planktivores), and five trophic guilds in the dry season (detritivores, insectivores, lepidophages, omnivores and piscivores). The smallest mean values of diet breadth were observed for the specialist guilds (detritivores, lepidophages and piscivores), in both seasons. The widest means for diet breadth were observed for the omnivores, regardless of the season. In general, there was no seasonal variation in feeding overlap among the species studied. At the community level, diet overlap values between species were low (< 0.4) for 80% of the pairs in each season, suggesting wide partitioning of the food resource. The fish assemblage showed a tendency toward trophic specialization, regardless of the season, although several species changed their diets. We might consider two non-excludent hypothesis: that there is no pattern on the use of seasonal food resources and/or probably there are several patterns, because each one is based on characteristics of the studied site and the taxonomic composition of the resident species.

Freshwater Mussels as a Prehistoric Food Resource

1974 ◽  
Vol 39 (3) ◽  
pp. 421-434 ◽  
Author(s):  
Paul W. Parmalee ◽  
Walter E. Klippel
Keyword(s):  
Mississippi River ◽  
Freshwater Mussels ◽  
Food Resource ◽  
Food Resources ◽  
Archaeological Sites ◽  
Eastern North America ◽  
Subsistence Economies ◽  
Level Data ◽  
Food Potential ◽  
Prehistoric Subsistence

AbstractThe explication of prehistoric subsistence economies has been of increasing interest to archaeologists. This emphasis is reflected, in part, by the considerable attention afforded faunal analyses in the recent archaeological literature. However, little effort has been made toward developing methods that permit meaningful comparisons of food resources at the interspecies level. Data pertinent to the calculation of both quantitative and qualitative food potential of many of the vertebrate animals represented in archaeological contexts are extant. These data are lacking for freshwater mussels, frequently found in archaeological sites in eastern North America. Information relevant to determining the food energy provided by freshwater mussels common to much of the Mississippi River drainage is presented. Results are applicable to more credible interpretations of prehistoric subsistence as related to animal food resources.

scholarly journals Aquatic insects as the main food resource of fish the community in a Neotropical reservoir

2009 ◽  
Vol 7 (4) ◽  
pp. 701-708 ◽  
Author(s):  
Ana Paula Vidotto-Magnoni ◽  
Edmir Daniel Carvalho
Keyword(s):  
Aquatic Insects ◽  
Food Resource ◽  
Gravimetric Method ◽  
Stomach Contents ◽  
Food Resources ◽  
Food Category ◽  
Main Food ◽  
Tietê River ◽  
Two Samples ◽  
Terrestrial Insects

We evaluated the feeding of fish species of the Nova Avanhandava Reservoir, low Tietê River, São Paulo State, Brazil. Fishes were collected in two stretches of the reservoir: Santa Bárbara (14 samples) and Bonito (two samples) between September 2002 and March 2004, using gill and seining nets. The results of stomach contents analysis were expressed with the frequency of occurrence and gravimetric method, combined in the Alimentary Index (AI). The 20 species studied consumed 52 food items, grouped in 10 food categories: aquatic insects, terrestrial insects, crustaceans, fish, macroinvertebrates, microcrustaceans, algae, vegetal matter, detritus/sediment and scales. The aquatic insects (mainly Chironomidae, Odonata and Ephemeroptera) were the most common food resources, consumed by 18 species. The diet composition of the community (species grouped) indicated that the dominant food category in the diet of fishes was aquatic insects (AI = 77.6%), followed by crustaceans (AI = 7.1%). Four trophic guilds were identified according a cluster analysis (Pearson distance): insectivorous (10 species), omnivorous (4 species), detritivorous (3 species) and piscivorous/carcinophagous (3 species). Despite the highest number of species, the insectivorous guild was responsible for more than 80% in captures in number and biomass (CPUEn and CPUEb). The low values of niche breadth presented by all species, along with the low values of diet overlap between species pairs indicate a high degree of food resources partitioning among species. The aquatic insects, despite being the main food resource of insectivorous fishes, also complemented the diet of other species, which demonstrate the importance of this food resource for the fish community, sustaining a high diversity, abundance and biomass of fishes.

Intraspecific variation in tree lizard escape behaviour in relation to habitat and temperature

Behaviour ◽  
2020 ◽  
Vol 157 (2) ◽  
pp. 185-204 ◽  
Author(s):  
Cynthia L. Morris ◽  
Matthew S. Lattanzio
Keyword(s):  
Antipredator Behaviour ◽  
Similar Response ◽  
Response Patterns ◽  
Escape Behaviour ◽  
Urosaurus Ornatus ◽  
Escape Theory ◽  
Habitat Gradients ◽  
Disturbance Gradient ◽  
Tree Lizards ◽  
Tree Lizard

Abstract Optimal escape theory has proven useful for understanding the dynamics of antipredator behaviour in animals; however, approaches are often limited to single-population studies. We studied how the escape behaviour of tree lizards (Urosaurus ornatus) varied across a disturbance gradient. We also considered how sex, body temperature, and perch temperature affected their escape decisions. Both sexes exhibited similar response patterns; however, lizards in the most-disturbed habitat, as well as cooler (body or perch temperature) lizards, initiated escape earlier (but did not flee further) than other animals. Increased wariness as indicated by earlier escape suggests that frequently-disturbed, more-open localities may be stressful habitats for species like U. ornatus. In addition, because cooler temperatures limit locomotor performance capacity, escape decisions should also depend on a species’ thermal ecology. Overall, we stress the importance of multi-population approaches for capturing the variety of ways species adaptively respond to the threat of predation across habitat gradients.

Delayed Breeding in Avian Social Systems: the Role of Territory Quality and "Floater" Tactics

Behaviour ◽  
1992 ◽  
Vol 123 (3-4) ◽  
pp. 194-219 ◽  
Author(s):  
Bridget J. Stutchbury ◽  
Steve Zack
Keyword(s):  
Social Systems ◽  
Breeding Site ◽  
Home Ranges ◽  
Territory Quality ◽  
High Quality ◽  
Direct Benefits ◽  
Potential Applications ◽  
Site Tenacity ◽  
Colonial Breeding ◽  
A Site

AbstractIn many avian societies, young birds delay breeding beyond the age of sexual maturity. Most previous hypotheses of delayed breeding have emphasized forces that keep young birds from becoming breeders. We develop a model of delayed breeding which includes the future acquisition of a high quality territory as a potential direct benefit of delayed breeding. Strong differences in territory quality, age-correlated asymmetries in resource holding potential, and territory site tenacity set the stage for young birds to either breed immediately on a poor territory, or obtain a high quality territory through reproductive delay on or near the site. A wide variety of species and social organizations reveal common patterns of breeding status acquisition through behaviours as nonbreeders with site tenacity on or immediately near the breeding site. A review of 'floater' strategies reveals that nonbreeders frequently have restricted home ranges that encompass one or more breeding territories, and prior experience at a site improves their chances of acquiring a territory in future years. This pattern of territory acquisition argues for incorporating direct benefits into models of delayed breeding. We discuss the potential applications to understanding delayed breeding in social systems as apparently different as cooperatively-breeding birds, migratory passerines, colonial breeding gulls, and lek-breeding grouse and manakins.

Ecological history of the koala and implications for management

2017 ◽  
Vol 44 (7) ◽  
pp. 471
Author(s):  
Vic Jurskis
Keyword(s):  
Land Management ◽  
Conservation Status ◽  
Nutrient Content ◽  
Food Resources ◽  
Ecological Perspective ◽  
Home Ranges ◽  
Ecological History ◽  
History Of ◽  
Low Levels ◽  
Eucalypt Forests

Assessments of the conservation status of koalas and trends in their population have been based on mostly unstated false assumptions about their pre-European status and on notions that either they were naturally regulated by their predators, chiefly Aborigines and dingoes, or that they somehow ‘self-regulated’ their fecundity. Closer examination of their ecological history suggests that frequent mild burning by Aborigines maintained eucalypt forests having fewer, mostly healthy trees, fewer young trees, canopies comprising mostly hard and dry leaves with low nutrient content, and, consequently, very few koalas. European explorers did not see them because they were solitary animals occupying large home ranges. After burning was disrupted, koalas responded to increased food resources in dense new growth of eucalypts and in stressed trees continually turning over new foliage. An export skin industry flourished. When their food resources were depleted by clearing or ringbarking of new growth and/or death of declining stands during droughts, koalas crashed back to low levels. Koalas continue to irrupt and decline through much of their range according to changing land management. Wildlife managers should re-assess their status and their management from a clear historical and ecological perspective.

The social organisation and mating system of an Australian subalpine rodent, the broad-toothed rat, Mastacomys fuscus Thomas

1993 ◽  
Vol 20 (4) ◽  
pp. 405 ◽  
Author(s):  
TM Bubela ◽  
DCD Happold
Keyword(s):  
Mating System ◽  
Social Organisation ◽  
Home Ranges ◽  
Spatial Organisation ◽  
Nest Sites ◽  
Alpine Regions ◽  
The Social ◽  
Eastern Australia ◽  
The World ◽  
Males And Females

Mastacomys fuscus is a grass-eating rodent of south-eastern Australia that lives mainly in subalpine habitats where snow covers the ground for about four months of the year. Radiotelemetry revealed that in summer the females were territorial. Home ranges of males were larger than those of females and overlapped extensively with the home ranges of other males and with the home ranges of up to three females. In winter, males and females huddled together in communal nests. The locations of nest sites, cover, water and grass also determined the spatial organisation of individuals. The evidence suggests that M. fuscus is not monogamous, but there were insufficient data to determine whether polygyny or promiscuity is the preferred mating system. The social organisation of this species, solitary in summer and communal in winter, is a response to the cold snowy winters and the limited time for reproduction in summer. The social organisation of M, fuscus is different from that of the other conilurine rodents of Australia, but similar to that of rodents that live in other alpine regions of the world.

Space use by female agile antechinus: are teat number and home-range size linked?

2016 ◽  
Vol 43 (4) ◽  
pp. 348 ◽  
Author(s):  
Juliey Beckman ◽  
Alan Lill
Keyword(s):  
Population Density ◽  
Home Range ◽  
Food Resource ◽  
Food Abundance ◽  
Energetic Cost ◽  
Home Ranges ◽  
Female Population ◽  
Eastern Australia ◽  
Minimal Convex ◽  
Teat Number

Context The number of teats that a female agile antechinus (Antechinus agilis) possesses effectively determines her initial litter size. In the Otway Ranges, south-eastern Australia, numerous separate populations in which all females have either six or 10 teats occur fairly close together in similar, contiguous forest at comparable altitudes and latitudes. Six-teat and 10-teat females have a similar mean mass, but the latter have a 1.7 × greater reproductive potential and so should have a greater nutritional requirement while raising young than do six-teat females. Theoretically, they could meet this requirement by occupying larger and/or more exclusive home ranges during breeding than do six-teat females do (provided that their food-resource abundance is comparable), albeit at a greater energetic cost. Aims The aim of the study was to determine whether 10-teat A. agilis females occupied larger and less overlapping home ranges than did six-teat females. To interpret the findings more meaningfully, it was necessary to compare food abundance and habitat characteristics in areas occupied by the two phenotypes. Methods The investigation was conducted in six-teat and 10-teat A. agilis areas in cool temperate forest over 22 months. Population density was determined by mark–recapture methods and arthropod prey biomass and abundance by pitfall trapping. Vegetation structure and plant-taxa abundance and diversity were determined by standard plant-survey methods. Female home-range estimates determined by radio-tracking were based on 95% minimal convex polygons (MCP) and kernel analysis. Home-range overlap was based on 80% MCP range determinations and core areas were calculated from utilisation plots. Key results Female population density was 2.5 × lower in exclusively 10-teat than in exclusively six-teat populations. Radio-tracked 10-teat females’ home ranges less commonly overlapped those of identified female neighbours and, on average, were 1.5 × larger than ranges of six-teat females. Food abundance and composition was similar in six-teat and 10-teat areas, but ground cover was denser and more complex in the latter areas. Conclusions Food-resource availability was similar in the six-teat and 10-teat phenotype areas, so the larger, and probably more exclusive, home ranges of 10-teat females could reflect greater nutritional requirements resulting from having larger litters, and account for their lower population density. Implications The A. agilis teat-number variation pattern in the Otways may be a rare, visible example of ongoing incipient speciation. This makes it of great scientific and conservation value and it is important to document how the phenomenon operates.

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