scholarly journals 31° South: Dietary niche of an arid-zone endemic passerine

2018 ◽  
Author(s):  
Ângela M. Ribeiro ◽  
Ben Smit ◽  
M. Thomas P. Gilbert
Keyword(s):  
Prey Availability ◽  
Arid Zone ◽  
Climatic Conditions ◽  
Arid Ecosystems ◽  
Energy Budgets ◽  
Sufficient Energy ◽  
Balancing Energy ◽  
Dietary Plasticity ◽  
Dietary Niche ◽  
Different Populations

ABSTRACTBalancing energy budgets is thought to be challenging for birds living in arid ecosystems because food supplies are low and unpredictable, and climatic conditions extreme. Thus, to ensure they obtain sufficient energy to fuel daily energetic budgets, birds may need to adjust their diets and become less selective (generalist) as conditions become harsher. To test this hypothesis, we used DNA metabarcoding to characterize both the prey availability and the dietary content of several conspecific populations of a semi- and arid-endemic insectivorous bird, the Karoo-scrub-robin (Cercotrichas coryphaeus) across a climatic gradient. Our results showed that Coleoptera, Hymenoptera, Orthoptera, and Lepidoptera were the main prey. When accounting for their presence as available prey, Coleoptera and Hymenoptera were preferred in all regions, whereas robins avoided Orthoptera and Lepidoptera in all but the most arid region. Although the different populations live in regions that vary with regards to productivity and thermoregulatory demands, we found that the dietary niche breadth (Bs) of the three populations was intermediate to low, and did not differ significantly. As a whole, our findings show that regardless of environmental harshness these insectivores have similar dietary niches, suggesting that large dietary plasticity is fundamental for their survival in energy-depauperated ecosystems.

scholarly journals Climatic Variation of Supercooling Point in the Linden Bug Pyrrhocoris apterus (Heteroptera: Pyrrhocoridae)

Insects ◽  
2018 ◽  
Vol 9 (4) ◽  
pp. 144 ◽  
Author(s):  
Tomáš Ditrich ◽  
Václav Janda ◽  
Hana Vaněčková ◽  
David Doležel
Keyword(s):  
Cold Tolerance ◽  
Minimum Temperature ◽  
Climatic Conditions ◽  
Climatic Variation ◽  
Strongly Correlated ◽  
Supercooling Point ◽  
Pyrrhocoris Apterus ◽  
Winter Minimum Temperature ◽  
Different Populations ◽  
Insect Fitness

Cold tolerance is often one of the key components of insect fitness, but the association between climatic conditions and supercooling capacity is poorly understood. We tested 16 lines originating from geographically different populations of the linden bug Pyrrhocoris apterus for their cold tolerance, determined as the supercooling point (SCP). The supercooling point was generally well explained by the climatic conditions of the population’s origin, as the best predictor—winter minimum temperature—explained 85% of the average SCP variation between populations. The supercooling capacity of P. apterus is strongly correlated with climatic conditions, which support the usage of SCP as an appropriate metric of cold tolerance in this species.

Flexible energetics of cheetah hunting strategies provide resistance against kleptoparasitism

Science ◽  
2014 ◽  
Vol 346 (6205) ◽  
pp. 79-81 ◽  
Author(s):  
David M. Scantlebury ◽  
Michael G. L. Mills ◽  
Rory P. Wilson ◽  
John W. Wilson ◽  
Margaret E. J. Mills ◽  
...  
Keyword(s):  
Population Viability ◽  
Energy Budgets ◽  
Hunting Strategies ◽  
Direct Competition ◽  
Daily Energy ◽  
Balancing Energy ◽  
Individual Survival ◽  
Power Outputs ◽  
Wild Dogs ◽  
Increased Activity

Population viability is driven by individual survival, which in turn depends on individuals balancing energy budgets. As carnivores may function close to maximum sustained power outputs, decreased food availability or increased activity may render some populations energetically vulnerable. Prey theft may compromise energetic budgets of mesopredators, such as cheetahs and wild dogs, which are susceptible to competition from larger carnivores. We show that daily energy expenditure (DEE) of cheetahs was similar to size-based predictions and positively related to distance traveled. Theft at 25% only requires cheetahs to hunt for an extra 1.1 hour per day, increasing DEE by just 12%. Therefore, not all mesopredators are energetically constrained by direct competition. Other factors that increase DEE, such as those that increase travel, may be more important for population viability.

scholarly journals Impact of climate and moonlight on a venomous mammal, the Javan slow loris (Nycticebus javanicus Geoffroy, 1812)

2014 ◽  
Vol 83 (4) ◽  
pp. 217-225 ◽  
Author(s):  
Eva Johanna Rode-Margono ◽  
K. Anne-Isola Nekaris
Keyword(s):  
Climatic Factors ◽  
Prey Availability ◽  
Interactive Effect ◽  
Weather Conditions ◽  
Climatic Conditions ◽  
Activity Level ◽  
Environmental Data ◽  
Foraging Efficiency ◽  
Slow Loris ◽  
Reduce Activity

Predation pressure, food availability, and activity may be affected by level of moonlight and climatic conditions. While many nocturnal mammals reduce activity at high lunar illumination to avoid predators (lunarphobia), most visually-oriented nocturnal primates and birds increase activity in bright nights (lunarphilia) to improve foraging efficiency. Similarly, weather conditions may influence activity level and foraging ability. We examined the response of Javan slow lorises (Nycticebus javanicus Geoffroy, 1812) to moonlight and temperature. We radio-tracked 12 animals in West Java, Indonesia, over 1.5 years, resulting in over 600 hours direct observations. We collected behavioural and environmental data including lunar illumination, number of human observers, and climatic factors, and 185 camera trap nights on potential predators. Nycticebus javanicus reduced active behaviours in bright nights. Although this might be interpreted as a predator avoidance strategy, animals remained active when more observers were present. We did not find the same effect of lunar illumination on two potential predators. We detected an interactive effect of minimum temperature and moonlight, e.g. in bright nights slow lorises only reduce activity when it is cold. Slow lorises also were more active in higher humidity and when it was cloudy, whereas potential predators were equally active across conditions. As slow lorises are well-adapted to avoid/defend predators by crypsis, mimicry and the possession of venom, we argue that lunarphobia may be due to prey availability. In bright nights that are cold, the combined effects of high luminosity and low temperature favour reduced activity and even torpor. We conclude that Javan slow lorises are lunarphobic – just as the majority of mammals.

Diets and foraging behaviour of red and eastern grey kangaroos in arid shrub land: is feeding behaviour involved in the range expansion of the eastern grey kangaroo into the arid zone?

2004 ◽  
Vol 26 (2) ◽  
pp. 169 ◽  
Author(s):  
TJ Dawson ◽  
KJ McTavish ◽  
BA Ellis
Keyword(s):  
Feeding Behaviour ◽  
Foraging Behaviour ◽  
Arid Zone ◽  
Foraging Strategies ◽  
Foraging Patterns ◽  
Grey Kangaroo ◽  
Macropus Rufus ◽  
Dietary Niche ◽  
Domestic Stock ◽  
Total Feeding

Eastern grey kangaroos (Macropus giganteus) have expanded into arid areas usually the habitat of red kangaroos (Macropus rufus). Extra watering sites for domestic stock is the suggested reason. However, changes in vegetation also have occurred due to grazing from domestic stock. We investigated the foraging strategies of M. giganteus and M. rufus in arid rangeland to see if these are involved in the range changes. Foraging patterns were similar, with both species mostly foraging at night; total feeding times were the same. M. giganteus and M. rufus had differing diets, though there was considerable overlap of 81 - 87%. Both species were highly selective, having similar narrow dietary niche breaths. Differences in plant preferences occurred and though both species had a preference for grass that of M. giganteus was higher. A larger foregut in M. giganteus reinforces its focus on grass. M. rufus also selected dicot forbs and malvaceous sub-shrubs. Both kangaroos showed avoidance of abundant chenopod shrubs (saltbushes and bluebushes) and trees. It is likely that the changes to arid-zone vegetation, with a shift to grass and annual dicot forbs, has been important for the expansion of M. giganteus, possibly combined with the greater availability of water.

Restoration of Arid and Semi-arid Ecosystems in Afghanistan

1977 ◽  
Vol 4 (4) ◽  
pp. 297-301 ◽  
Author(s):  
Amir S. Hassanyar
Keyword(s):  
Plant Biomass ◽  
Climatic Conditions ◽  
Species Selection ◽  
Arid Ecosystems ◽  
Topographic Map ◽  
Soil Series ◽  
Resistant Species ◽  
Planting Methods ◽  
Physical And Chemical ◽  
Semi Arid

Barren, desert-like environments have been created over large areas in Afghanistan, and various degrees of desertification can be seen especially in the southwestern plains. Extensive overgrazing, frequent drought, and unwise land-use, have initiated processes of local desertification also elsewhere in Afghanistan.The first step in the restoration of depleted vegetation is to correct the improper uses that have been responsible for these conditions. Improper grazing practices of rangelands are a primary cause of reductions in the productivity of arid and semi-arid ecosystems in Afghanistan.The second step in restoration is to prepare a detailed revegetation plan. The following maps and information are needed: (1) a vegetation-cover map, (2) a soil-series map, (3) a topographic map, and (4) baseline data on climatic conditions. The vegetationcover map identifies the plant biomass potential and the species that might be suitable for revegetation. The soil-series map is accompanied by a description of the physical and chemical features of the topsoil and subsoil along with an assessment of the general herbage production potential. The topographic map helps with species selection and planting methods. The climatic parameters assist in determining the season of planting and any need for drought-resistant species to be planted.

Formation of honey bees modern look and their reproduction in the republic of Dagestan

10.12737/6540 ◽  
2014 ◽  
Vol 9 (3) ◽  
pp. 117-119
Author(s):  
Гасанов ◽  
Alibulat Gasanov ◽  
Абакарова ◽  
Muslimat Abakarova
Keyword(s):  
Honey Bees ◽  
Wing Length ◽  
Climatic Conditions ◽  
High Mountains ◽  
Mountainous Areas ◽  
The Third ◽  
Different Populations ◽  
Natural Breeding ◽  
The Republic ◽  
Natural Dispersal

Grey mountain Caucasian bees are of great interest for the selection, as a valuable gene pool of different populations of this race is supported by high mountains and inaccessible gorges of Dagestan, while serving as an isolated mountainous natural breeding areas. The studies were conducted in three different climatic conditions of the republic: the plains, foothills and mountainous areas. In the area of natural dispersal of gray mountain Caucasian bees in Dagestan released several local populations and different backgrounds. Characteristics of the main morphological features of honey bees are the length of proboscis, wing and width of the third tergite and others. These features bees vary, depending on the habitat population. Numerous studies of Dagestan honeybees showed, that the longest proboscis inherent in bees of mountain zone (6.85 ± 0.03 mm). The plain bees have a smaller proboscis (up to 6.71 ± 0.01 mm), and in the foothills bees the proboscis occupies an intermediate position (from 6.69 ± 0.01 to 6.83 ± 0.01 mm). Two other peculiarities (wing length and the third tergite) are subject to variation, depending on the altitude above sea level.

SUPPLEMENTAL POLLINATION – INCREASING OLIVE (OLEA EUROPAEA) YIELDS IN HOT, ARID ENVIRONMENTS

2004 ◽  
Vol 40 (4) ◽  
pp. 481-491 ◽  
Author(s):  
RICARDO AYERZA ◽  
WAYNE COATES
Keyword(s):  
Sonoran Desert ◽  
Olea Europaea ◽  
Fruit Set ◽  
Climatic Conditions ◽  
Arid Ecosystems ◽  
Arid Environments ◽  
Olive Trees ◽  
La Rioja ◽  
Supplemental Pollination ◽  
Arid Chaco

In general, olive trees are self-compatible, but under some climatic conditions a number of cultivars have demonstrated problems with pollination and fruit set. The Manzanillo cultivar is usually self-pollinating, but under hot conditions its pollen develops slowly, resulting in little or no fertilization. Trials were carried out in two hot, arid ecosystems (Arid Chaco in La Rioja, Argentina and Sonoran Desert in Arizona, USA) to determine if supplemental pollination of a Manzanillo cultivar has the potential to increase yields, and to assess the effectiveness of three different cultivars as sources of pollen. Branches that received supplemental pollination produced 21% more total olives than the control. In Arizona, total olive and shotberry (unpollinated olive) production were significantly different between treatments. Branches that received supplemental pollination produced 98% more olives, and had 58% fewer shotberries than did branches in the control rows. Significantly more olives were produced on branches pollinated with Sevillano and Arbequina pollen, compared with those pollinated with Ascolano pollen and with the control.

Dynamique de la régénération d'une pessière à lichen dans la zone de la pessière noire à mousses, nord du Saguenay–Lac-Saint-Jean (Québec)

1996 ◽  
Vol 26 (8) ◽  
pp. 1504-1509 ◽  
Author(s):  
Stéphane Riverin ◽  
Réjean Gagnon
Keyword(s):  
Black Spruce ◽  
Adult Population ◽  
Climatic Conditions ◽  
Population History ◽  
Taiga Zone ◽  
Forest Zone ◽  
Dating Method ◽  
Different Populations ◽  
Cross Dating ◽  
Open Forests

Regeneration dynamics have been studied in three open lichen–spruce woodlands located in the black spruce feather-moss forest zone. Black spruces (Piceamariana (Mill.) BSP) belonging to the adult stratum originated from a fire that occurred in 1877. Population history and ecology has been studied on the basis of the establishment period of individuals. The age of black spruces belonging to the regeneration stratum was calculated by using the cross-dating method. The establishment period of the seedlings was determined by the age structure. The black spruces of these open forests belong to two different populations. The adult population originated from the 1877 fire whereas the regeneration population seems to have established itself following another fire that occurred in 1922–1923. Black spruce seedlings of the regeneration stratum are very old (60 years-old on average) in spite of a low height (mean height of 96 cm). Although these open forests are under favourable climatic conditions, they have dynamics similar to lichen–spruce woodlands of the taiga zone. In the last 45 years, no seedlings have settled in these sparse forests.

scholarly journals Dietary plasticity of North American herbivores: a synthesis of stable isotope data over the past 7 million years

2021 ◽  
Vol 288 (1948) ◽  
Author(s):  
Melissa I. Pardi ◽  
Larisa R. G. DeSantis
Keyword(s):  
Stable Isotope ◽  
North American ◽  
Tooth Enamel ◽  
Local Level ◽  
Habitat Preferences ◽  
Dietary Behaviour ◽  
The Past ◽  
Dietary Breadth ◽  
Dietary Plasticity ◽  
Dietary Niche

Palaeoecological interpretations are based on our understanding of dietary and habitat preferences of fossil taxa. While morphology provides approximations of diets, stable isotope proxies provide insights into the realized diets of animals. We present a synthesis of the isotopic ecologies ( δ 13 C from tooth enamel) of North American mammalian herbivores since approximately 7 Ma. We ask: (i) do morphological interpretations of dietary behaviour agree with stable isotope proxy data? (ii) are grazing taxa specialists, or is grazing a means to broaden the dietary niche? and (iii) how is dietary niche breadth attained in taxa at the local level? We demonstrate that while brachydont taxa are specialized as browsers, hypsodont taxa often have broader diets that included more browse consumption than previously anticipated. It has long been accepted that morphology imposes limits on the diet; this synthesis supports prior work that herbivores with ‘grazing’ adaptions, such as hypsodont teeth, have the ability to consume grass but are also able to eat other foods. Notably, localized dietary breadth of even generalist taxa can be narrow (approx. 30 to 60% of a taxon's overall breadth). This synthesis demonstrates that ‘grazing-adapted’ taxa are varied in their diets across space and time, and this flexibility may reduce competition among ancient herbivores.

scholarly journals Food Security and Socio-Economic Uplift of Camel Herders in Southern Punjab, Pakistan

Land Science ◽  
2020 ◽  
Vol 2 (2) ◽  
pp. p8
Author(s):  
Asim Faraz
Keyword(s):  
Food Security ◽  
Arid Zone ◽  
Economic Status ◽  
Domestic Animals ◽  
Climatic Conditions ◽  
Extension Education ◽  
Socio Economic Status ◽  
The People ◽  
Valuable Product ◽  
Semi Arid

This study belongs to project “Rural development by livestock extension education in Southern Punjab”. A survey was conducted in Multan and Muzaffargarh districts of Southern Punjab by using a pretested questionnaire to collect the information regarding food security and socio-economic status of cameleers in study area. It has been shown from the results that the socio-economic status of camel herders has improved a lot in last decade mainly due to the knowledge about camel and its products. Definitely camel plays an indispensable role in the food security of people of arid zone. Now the people are getting conscious about consuming the camel milk and products as in earlier time there was a taboo to use the camel products and the people did not get their taste developed. Due to increasing health reasons and by the initiatives taken by government departments the people are getting familiar with the camel products. Now the camel has shifted its place from “ship of the desert” and “beast of the burden” to a “food security animal” with great potential to produce a valuable product even in those areas of harsh climatic conditions where there seems difficult for the other domestic animals to produce. The camel herders value the ethno-veterinary practices and still use these for the treatment in camels. Mainly the camel browse on the roadsides but also stallfed with fodder by cut and carry system. The camel plays a pivotal role in the life sustainability of cameleers where they mainly depend on this specie for their livelihood. Hence; this is an integral part of pastoral ecosystem in arid, semi-arid and deserted lands.

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