Exploitative competition between desert kit foxes and coyotes in the Mojave Desert

2020 ◽  
Vol 26 (1) ◽  
pp. 57
Author(s):  
Erica C. Kelly ◽  
Brian L. Cypher ◽  
David J. Germano
Keyword(s):  
Mojave Desert ◽  
Food Habits ◽  
Dietary Diversity ◽  
Conservation Strategies ◽  
Natural Food ◽  
Exploitative Competition ◽  
Ecological Community ◽  
Food Items ◽  
Heteromyid Rodents ◽  
Abundance And Diversity

Exploitative competition between two sympatric guild members can influence the composition and dynamics of an ecological community. We assessed potential exploitative competition between desert kit foxes (Vulpes macrotis arsipus) and coyotes (Canis latrans) by comparing food habits of the two species from 2009 to 2014 on a study site in the Mojave Desert in California. Desert kit foxes specialised on heteromyid rodents and invertebrates, while the most frequently occurring items consumed by coyotes were lagomorphs and rodents. Both species consumed a variety of food items throughout the study, but relative use of these items varied with year and season. Also, precipitation affected prey abundance, and this influenced prey consumption by the two species. The diets of desert kit foxes and coyotes overlapped extensively, which indicated possible exploitative competition. Desert kit foxes consistently had lower dietary diversity than coyotes, indicating that desert kit foxes are more specialist consumers while coyotes are more generalists. Dietary specialisation by kit foxes on smaller items may help reduce competition with coyotes and facilitate coexistence. Coyotes consumed anthropogenic material at much higher frequencies than desert kit foxes, and this subsidisation could increase competitive pressures on kit foxes if it results in greater coyote abundance. Desert kit foxes in California are not a protected species although formal protection has been proposed due to increasing human encroachment. Conservation strategies should include measures to maintain an abundance and diversity of natural food items and limit anthropogenic subsidisation of coyotes.

scholarly journals Condition Factor, Food and Feeding Habit of Chrysichthys nigrodigitatus (Siluriformes: Bagridae) from Lower River Benue, Makurdi, Nigeria

2019 ◽  
pp. 1-7
Author(s):  
Edem, Edem Thomas ◽  
Odey, Christopher Ogamode
Keyword(s):  
Food Habits ◽  
Condition Factor ◽  
Stomach Contents ◽  
Good Health ◽  
Feeding Habit ◽  
Natural Food ◽  
Frequency Of Occurrence ◽  
Food Items ◽  
Significant Difference ◽  
Food And Feeding

Background and Objective: The feeding habit as well as the condition factor of Chrysichthys nigrodigitatus from lower river Benue was studied between July 2015 and September 2015. Materials and Methods: The natural food of the fish in the Lower River Benue was studied from stomach contents of the fish. A total of 100 stomachs were randomly examined and analyzed using two methods; the frequency of occurrence and point methods. About 92 had food items while 8 were empty. Analysis of variance (ANOVA) was used to test for significant difference at 95% confidence limit in the food eaten by these species and also the degree of stomach fullness. Results: Food items encountered using frequency of occurrence method include fish parts (47.62%), seeds (40.49%), sand/mud (30.09%), detritus (30.95%), digested food (29.76%), insect parts (27.38%), mollusk (25.00%) and algae (22.62%). Conclusion: C. nigrodigitatus had a euryphagous food habits and based on condition factor the fish were in good health.

scholarly journals Coyote diet patterns in the Mojave Desert: implications for threatened desert tortoises

2018 ◽  
Vol 24 (1) ◽  
pp. 44 ◽  
Author(s):  
Brian L. Cypher ◽  
Erica C. Kelly ◽  
Tory L. Westall ◽  
Christine L. Van Horn Job
Keyword(s):  
Mojave Desert ◽  
Dietary Diversity ◽  
Generalist Predators ◽  
Gopherus Agassizii ◽  
Low Frequencies ◽  
Diet Patterns ◽  
Food Items ◽  
High Predation ◽  
Anthropogenic Food ◽  
Predation Rates

Coyotes (Canis latrans) are generalist predators and are ubiquitous in North America. Occasionally, predation by coyotes can pose a threat to populations of rare species. We assessed diet patterns of coyotes over a 5-year period (2009–14) in a region of the Mojave Desert where high predation rates on threatened desert tortoises (Gopherus agassizii) had been reported. Our goal was to identify primary food items for coyotes and to assess the importance of desert tortoises in the diet. Coyotes primarily consumed rabbits and rodents with rabbits being consumed preferentially and rodents, along with secondary foods including various birds, reptiles, arthropods, and fruits, being consumed more opportunistically. In response to low annual precipitation in the last three years of the study, dietary diversity increased, as did use of anthropogenic food items by coyotes. However, coyotes did not seem to be dependent upon anthropogenic items. Remains of desert tortoises occurred in coyote scats at low frequencies (<6%) in all years and seasons, and use of tortoises appeared to be opportunistic as use varied with tortoise abundance. In the portion of the study area where 571 translocated desert tortoises had been released in 2008, the frequencies of tortoise remains in coyote scats were markedly higher in the two years following the releases (7.5% and 8.8%, respectively). The high predation rates on tortoises reported in this area may have resulted from focussed coyote foraging efforts due to the availability of vulnerable individuals (e.g. disoriented and displaced tortoises) as well as higher tortoise densities.

scholarly journals Outbreak of S. Weltevreden linked to fermented cashew nut cheese in Victoria, BC

2018 ◽  
Vol 61 (3) ◽  
pp. 74-81 ◽  
Author(s):  
Nicolas Schmitt ◽  
Gloria Yu ◽  
Richard Greve ◽  
Lorraine McIntyre
Keyword(s):  
High Risk ◽  
Temperature Control ◽  
Starter Culture ◽  
Clinical Samples ◽  
Natural Food ◽  
Food Items ◽  
Cashew Nut ◽  
Risk Practices ◽  
Food Processes ◽  
Single Batch

Twenty-three Salmonella enterica serovar Weltevreden (S. Weltevreden) illnesses occurred in a Victoria, British Columbia, Canada, restaurant following consumption of fermented vegan cheese. Three clusters of illness over 2 days were traced to a single batch of fermented cashew cheese spread. S. Weltevreden was detected in 11 clinical samples and in the cashew cheese spread. An inspection of the restaurant and review of the food processes revealed high-risk practices, such as use of rejuvelac as a starter culture for fermentation and poor temperature control. Three of five vegan and natural food restaurants in the Victoria area were using similar methods, indicating this type of product was common. Procedures to safely ferment vegan cheese spreads are presented. We also discuss higher-risk food items and practises noted in this event that inspectors should be aware of during inspections.

scholarly journals Comparison of Body Composition and Fatty Acid Profiles between Wild and Cultured Rio Grande Silvery Minnows

2017 ◽  
Vol 8 (2) ◽  
pp. 487-496 ◽  
Author(s):  
Madison S. Powell ◽  
Ronald W. Hardy ◽  
Alison M. Hutson ◽  
Louie A. Toya ◽  
Douglas Tave
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Artificial Diet ◽  
Condition Factor ◽  
Rio Grande ◽  
Wild Fish ◽  
Natural Food ◽  
Fatty Acid Profiles ◽  
Food Items ◽  
Supplementary Feed

Abstract Federally endangered Rio Grande Silvery Minnows (RGSM; Hybognathus amarus) were raised in one of three culture regimes: intensively, with only a hatchery diet; semi-intensively with access to natural food and hatchery diet supplementation; and with only natural food available at the Los Lunas Silvery Minnow Refugium (Los Lunas, New Mexico), a naturalized conservation refugium designed to mimic the natural environment of the RGSM in the Rio Grande. The project compared each culture regime and assessed differences and similarities in lipid and fatty acid content between feeding an artificial diet and consumption of natural food items in this species. After 117 d, whole-body lipid levels and fatty acid profiles were measured in each group and compared with values for wild RGSM. Fish fed the hatchery diet exclusively or as supplementary feed had significantly higher percent lipid (15.5% ± 0.5% and 10.6% ± 0.1%, respectively) than fish raised without access to the diet. Both groups had significantly higher percent lipid than fish raised in the refugium or wild fish (8.3% ± 0.1% and 7.8% ± 0.2%, respectively). Condition factor differed among groups and was highest in fish fed the hatchery diet (1.00) followed by fish supplemented with the hatchery diet (0.93), refugium fish (0.91), and wild fish (0.90). In this respect, refugium fish appeared more similar to wild fish than fish fed the hatchery diet or offered the diet as a supplement. Comparison of fatty acid profiles among groups showed marked differences among wild fish, refugium fish, and those fed the hatchery diet, either exclusively or as supplementary feed. Total omega-3 fatty acids, expressed as percentage of total fatty acids, were highest in wild fish but similar among other groups. Total omega-6 fatty acids showed an opposite trend, with five to nine times higher percentages of linoleic acid observed among fish from the three culture regimes compared with wild fish. Significant differences in lipid content and fatty acid composition between wild RGSM and cultured silvery minnows reflected their respective diets and culture regimes. Given similarities in fat content and condition factor with wild RGSM, we conclude that fish in the refugium do not require supplemental feeding with an artificial diet for this type of naturalized conservation management. Results from this study show that RGSM readily forage on natural food items present and also artificial feed when available, indicating dietary plasticity, which is advantageous for fish culture and future recovery.

scholarly journals Diet of Ornate Hawk-Eagle (Spizaetus ornatus)

2019 ◽  
Vol 27 (1) ◽  
pp. 31-39 ◽  
Author(s):  
Fagner Daniel Teixeira ◽  
Elisa Paraíso Mesquita ◽  
Michele Alves Ferreira ◽  
Felipe Carvalho de Araújo
Keyword(s):  
Literature Review ◽  
Field Observation ◽  
Food Habits ◽  
Bird Species ◽  
Young Individual ◽  
Top Predator ◽  
Espinhaço Range ◽  
Food Items ◽  
Minas Gerais State ◽  
Report Data

AbstractThe Ornate Hawk-Eagle (Spizaetus ornatus) is a top predator and inhabits mainly preserved forests. It occurs from Mexico to Argentina and throughout Brazil, where it is threatened by extinction. It hunts birds, mammals and reptiles, picking up both on the ground and on the branches in the forest. Here we report data on a pair and one young individual of this species registered in the southeast of Minas Gerais state, eastern portion of the Espinhaço Range, Brazil. In addition, a literature review on the diet of the species was carried out aiming gather data on food habits. The nesting territory, as well as the nest was discovered in semi-deciduous seasonal forest area. We recorded predation of a Lesser Yellow-headed Vulture (Cathartes burrovianus) by the young. After two days of observation, the nest was overthrown, what allowed its screening for other food items discovered after analysis of some feathers and bones. Detailed records of predation of S. ornatus were non-existent or inaccurate. Taking together our own field observation and the literature review, we found 121 taxa consumed by S. ornatus. A total of 78 bird species were reported, mainly Galliformes, followed by medium-sized mammals (38 species), well represented by Rodentia and Primates.

scholarly journals Food Habits of Dabbling Ducks During Fall Migration in a Prairie Pothole System, Heron Lake, Minnesota

2005 ◽  
Vol 119 (4) ◽  
pp. 546 ◽  
Author(s):  
Ryan M. Wersal ◽  
Brock R. McMillan ◽  
John D. Madsen
Keyword(s):  
Food Habits ◽  
Food Item ◽  
Dabbling Ducks ◽  
Prairie Pothole ◽  
Plant Parts ◽  
Food Items ◽  
Dabbling Duck ◽  
Stuckenia Pectinata ◽  
Polygonum Lapathifolium ◽  
Volume Method

We conducted an analysis of dabbling duck food habits in the fall of 2002 and 2003 in the Heron Lake system. Gizzard contents of hunter-harvested birds were analyzed using the percent aggregate volume method to determine what food items were consumed and in what quantity. Curltop Ladysthumb (Polygonum lapathifolium) was the food item consumed most often (82.2%) and in the greatest volume (34.2 ml). Sago Pondweed (Stuckenia pectinata) was the only food item of which multiple plant parts were consumed. However, the seeds and tubers only comprised 1.27 and 0.07 of the total aggregate percent.

scholarly journals Ecomorphology and food habits of teleost fishes Trachinotus carolinus (Teleostei: Carangidae) and Menticirrhus littoralis (Teleostei: Sciaenidae), inhabiting the surf zone off Niterói, Rio de Janeiro, Brazil

2010 ◽  
Vol 58 (spe4) ◽  
pp. 1-9 ◽  
Author(s):  
Luana Prestrelo Palmeira ◽  
Cassiano Monteiro-Neto
Keyword(s):  
Fish Species ◽  
Food Habits ◽  
Diet Composition ◽  
Surf Zone ◽  
Fish Larvae ◽  
Sandy Beaches ◽  
Size Class ◽  
Class I ◽  
Teleost Fishes ◽  
Food Items

The ecomorphology and food habits of juvenile Trachinotus carolinus and Menticirrhus littoralis caught in the surf zone of sandy beaches in Niterói, RJ, were investigated between July 2006 and May 2007. These fish species differ morphologically, but present similarities in their diet composition suggest some slight overlapping in their diet. The importance of food items was assessed using Kawakami and Vazzoler's feeding index. Morphometric variables were recorded to correlate with the diet composition of the different size classes for each species. A total of 210 fishes (Trachinotus carolinus - 122, Menticirrhus littoralis - 88), ranging between 24.2 mm and 112 mm total length, were analyzed, but the stomachs of only 84.8% of them contained food. Trachinotus carolinus presented mysids, Polychaetes and Emerita spp. as the predominant items in their diet. Formicidae and Isopoda were the most important items for class I individuals, whereas mysids and Emerita spp. were important for classes II and III. Class I individuals also showed smaller sized prey (amphipods and isopods) and clupeid fish larvae in their diet. Emerita spp. dominated the food items of Menticirrhus littoralis regardless of the size class. Polychaetes, the second most important item was better represented in class sizes II and III. The main morphometric variable correlated with such differences included mouth position and diameter of the eye.

scholarly journals Investigating differences in dietary patterns among a small cross-sectional study of young and old Pacific peoples in NZ using exploratory factor analysis: a feasibility study

BMJ Open ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. e023126 ◽  
Author(s):  
Ridvan Tupai-Firestone ◽  
Soo Cheng ◽  
Joseph Kaholokula ◽  
Barry Borman ◽  
Lis Ellison-Loschmann
Keyword(s):  
New Zealand ◽  
Dietary Patterns ◽  
Generational Differences ◽  
Dietary Diversity ◽  
Limited Range ◽  
Healthy Diet ◽  
Food Groups ◽  
Cross Sectional ◽  
Food Items ◽  
The Relationship

ObjectivesObesity among Pasifika people living in New Zealand is a serious health problem with prevalence rates more than twice those of the general population (67% vs 33%, respectively). Due to the high risk of developing obesity for this population, we investigated diet quality of Pacific youth and their parents and grandparents. Therefore, we examined the dietary diversity of 30 youth and their parents and grandparents (n=34) to identify whether there are generational differences in dietary patterns and investigate the relationship between acculturation and dietary patterns.MethodsThe study design of the overarching study was cross-sectional. Face-to-face interviews were conducted with Pasifika youth, parents and grandparents to investigate dietary diversity, that included both nutritious and discretionary food items and food groups over a 7 day period. Study setting was located in 2 large urban cities, New Zealand. Exploratory factor analyses were used to calculate food scores (means) from individual food items based on proportions consumed over the week, and weights were applied to calculate a standardised food score. The relationship between the level of acculturation and deprivation with dietary patterns was also assessed.ResultsThree distinctive dietary patterns across all participants were identified from our analyses. Healthy diet, processed diet and mixed diet. Mean food scores indicated statistically significant differences between the dietary patterns for older and younger generations. Older generations showed greater diversity in food items consumed, as well as eating primarily a ‘healthy diet’. The younger generation was more likely to consume a ‘processed diet’. There was significant association between acculturation and deprivation with the distinctive dietary patterns.ConclusionOur investigation highlighted generational differences in consuming a limited range of food items. Identified dietary components may, in part, be explained by specific acculturation modes (assimilation and marginalised) and high socioeconomic deprivation among this particular study population.

scholarly journals Disparities in food habits across Europe

2002 ◽  
Vol 61 (4) ◽  
pp. 553-558 ◽  
Author(s):  
Antonia Trichopoulou ◽  
Androniki Naska ◽  
Tina Costacou ◽  
Keyword(s):  
Food Availability ◽  
Food Habits ◽  
Economic Status ◽  
Household Head ◽  
Food Preferences ◽  
Food Purchasing ◽  
Food Items ◽  
The North ◽  
Fresh Vegetables ◽  
European Populations

Socially-and culturally-patterned differences in food habits exist both between and within European populations. Daily individual food availability data, collected through the national household budget surveys (HBS) and harmonized in the context of the Data Food Networking (DAFNE) project, were used to assess disparities in food habits of seven European populations and to evaluate dietary changes within a 10-year interval. The availability of selected food items was further estimated according to the educational level of the household head and, based only on the Greek HBS data, according to quintiles of the household's food purchasing capacity. Results for overall food availability support the north-south differentiation in food habits. Generally, the availability of most food items, including foods such as vegetable fats, animal lipids and sugar products, has decreased over the 10 years. Households in which the head was in the higher education categories reported lower availability for most food items, with the exception of low-fat milk, fresh fruit, animal lipids and soft drinks; the latter showing a sharp increase even within southern European households. The household's food purchasing capacity can be used as an indicator of socio-economic status, with higher values being associated with lower status. Greek households of lower social class follow a healthier diet in terms of greater availability of vegetable oils, fresh vegetables, legumes, fish and seafood. Data from the DAFNE databank may serve as a tool for identifying and quantifying variation in food habits in Europe, as well as for providing information on the socio-economic determinants of food preferences.

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