Dr. Sajjan Singh
Principal Scientist, Animal Physiology, ICAR-CIRB Hisar
Resilience refers to the idea of an individual’s tendency to cope with stress and adversity. This coping may result in the individual “bouncing back” to a previous state of normal functioning, or using the experience of exposure to adversity to produce a “steeling effect” and function better than expected (much like an inoculation gives one the capacity to cope well with future exposure to disease). Resilience is most commonly understood as a process, and not a trait of an individual. Recently there has also been evidence that resilience can indicate a capacity to resist a sharp decline in functioning even though an individual temporarily appears to get worse. Resilience is a dynamic process whereby individuals exhibit positive behavioral adaptation when they encounter significant adversity, trauma, tragedy, threats, or even significant sources of stress. It is a two-dimensional construct concerning the exposure of adversity and the positive adjustment outcomes of that adversity. This two-dimensional construct implies two judgments: one about a “positive adaptation” and the other about the significance of risk (or adversity). Positive adaptation, on the other hand, is considered in a demonstration of manifested behavior on social competence. Resilience is better understood as the opportunity and capacity of individuals to navigate their way through difficult situations. Climate change refers to a statistically significant variation in either the mean state of the climate or in its variability, persisting for an extended period (typically decades or longer). Climate change may be due to natural internal processes or external forcing, or to persistent anthropogenic changes in the composition of the atmosphere or in land use. Precisely at a time when India is confronted with development imperatives, we will also be severely impacted by climate change. Like other developing countries, several sections of the Indian populace will not be able to buffer themselves from impacts of global warming. With close economic ties to natural resources and climate-sensitive sectors such as agriculture, water and forestry, India may face a major threat, and require serious adaptive capacity to combat climate change. As a developing country, India can little afford the risks and economic backlashes that industrialized nations can. With sizable population still below the poverty line, reducing vulnerability to the impacts of climate change is essential. The future impacts of climate change, identified by the Government of India’s National Communications (NATCOM) in 2004 include
• Decreased snow cover, affecting snow-fed and glacial systems such as the Ganges and Bramhaputra. 70% of the summer flow of the Ganges comes from meltwater
• Erratic monsoon with serious effects on rain-fed agriculture, peninsular rivers, water and power supply
• Drop in wheat production by 4-5 million tones, with even a 1ºC rise in temperature
• Rising sea levels causing displacement along one of the most densely populated coastlines in the world, threatened freshwater sources and mangrove ecosystems
• Increased frequency and intensity of floods. Increased vulnerability of people in coastal, arid and semi-arid zones of the country
• Studies indicate that over 50% of India’s forests are likely to experience shift in forest types, adversely impacting associated biodiversity, regional climate dynamics as well as livelihoods based on forest products.
By the 20th century, scientists had rejected old tales of world catastrophe, and were convinced that global climate could change only gradually over many tens of thousands of years. But in the 1950s, a few scientists found evidence that some changes in the past had taken only a few thousand years. During the 1960s and 1970s other data, supported by new theories and new attitudes about human influences, reduced the time a change might require to hundreds of years. Many doubted that such a rapid shift could have befallen the planet as a whole. The 1980s and 1990s brought proof that the global climate could indeed shift, radically and catastrophically, within a century — perhaps even within a decade. The potential future effects of global climate change include more frequent wildfires, longer periods of drought in some regions and an increase in the number, duration and intensity of tropical storms. Global climate change has already had observable effects on the environment. Glaciers have shrunk, ice on rivers and lakes is breaking up earlier, plant and animal ranges have shifted and trees are flowering sooner.Speciation is an evolutionary process by which new ecological species arise. Due to various natural processes including geographical separation and drift, some species are becoming separated. In consequence, under changing environmental and climatic conditions and due to natural selection, new species are established. These are extremely slow processes that take many millennia and centuries to happen. During the last few centuries however, people started moving over large distances at an accelerating pace and shipping a larger volume of commodities to far-away destinations. This ever-increasing massive and rapid movement of people and goods has been facilitating the transport of various plants, animals and organisms to completely new, non-indigenous environments. Upon encountering new ecosystems, many of these intentionally or accidentally brought organisms may perish, not being able to survive in foreign environmental conditions. Some of them may be able to survive only if they are deliberately cultivated. Finally, some of them will become invasive, establishing their presence and spreading over a non-native environment. Climate change is altering vital aspects of the environment like temperature and precipitation, the frequency of extreme weather events, as well as atmospheric composition and land cover. The temperature, atmospheric concentration of carbon dioxide (CO2) and available nutrients are the key factors that will drive species survival; changes in these factors will most likely stress the ecosystems and the chances of invasions The process of establishment of species has received wide research attention. Many scientists agree that climate change will alter destination habitat and increase vulnerability to invasion because of resource scarcity and increased competition among native fauna and flora. Animals in the desert must survive in a hostile environment. Intense heat, searing sun, and lack of water are just a few of the challenges facing desert animals.
Animals that live in the hot desert have many adaptations. Some animals never drink, but get their water from seeds (some can contain up to 50% water) and plants. Many animals are nocturnal, sleeping during the hot day and only coming out at night to eat and hunt. Some animals rarely spend any time above ground. It is pertinent to point out that desert inhibiting organisms share most genetic and physiological traits with closely related species living in mesic environments. The suites of adaptive physiological traits of desert species are those that allow the organism to remain within the survivable thermal energy balance and water balance. It is important to understand that many species of desert plants and animals are living close to their limits of tolerance for one or more environment variables. Many desert animals are able to behaviorally seek out benign microclimates. Animals that are capable of maintaining temperature close to optimum for longer periods of time have an advantage in obtaining necessary resources. High temperature and dry air increases water needs thus requiring behavioral and/or physiological mechanisms for reducing water loses. There are several general categories of adaptations of animals that contribute to success of many species in hot arid environment. These include avoidance of extremes, a physiological and morphological characteristic that reduces water loses and thermal stress, rapid response to availability of water and nutrients, reduced metabolic rates and mechanisms to conserve essential nutrients. Camel is one such species that have all these physiological and morphological characteristics that reduces water loses and thermal stress.
Morphological Characteristics:
1. Feet suitable for sandy soils-Padded feet are convenient for sandy soils and also for other difficult terrains. Toenails protect the feet damage from a bump. Calloused structures on feet protect the animals from injuries and extreme hot grounds during hot summer. Padded feet helps camel walk in sandy soils without sinking.
2. Chest Pad-Also called as sternal pad keep the body elevated from hot ground while in sitting position and protect from hot grounds. It helps in copulation and acts as an external lock with prominences of pelvic girdle during mating and avoids slipping.
3. Eyelashes-The eyes of camels have two eyelash layers. The eyelashes interlock like a trap and protect the eyes of the animal from harsh sand storms.
4. Nostrils- Nostrils are naturally designed in such a way that air enters but keep out sand. A feature of their nostrils is that a large amount of water vapor in their exhalations is trapped and returned to their body fluids, thereby reducing the amount of water lost through respiration
5. Split Upper Lip- The camel’s split upper lip allows it to grip and draw food into its mouth. Its lips are also very tough to protect against thorny desert plants.
6. Hump-Camels are best known for their impressive fat-storing humps that are prominent on the camels back. This fat can be used in emergency as energy and water source.
7. Skin-Camels rarely sweat, even in desert temperatures that reach 120°F (49°C), so when they do take in fluids they can conserve them for long periods of time. In winter, even desert plants may hold enough moisture to allow a camel to live without water for several weeks.
8. Fur-The dense wool like hair layer reduces insensible evaporative water loses and reduces the rate of heat gain of camel exposed to the intense thermal environment of a mid day summer. All camels lose their fur in spring and grow a new coat.
9. Long Legs-When a camel walks, it moves both legs on one side and the both legs on the other, rocking side-to-side. This is why camels are nicknamed “The ships of the desert.” Camel legs are incredibly strong, which allows them to carry up to 1000 pounds. They also can walk 100 miles per day and sprint at 12 miles per hour. Legs keep camel body sufficiently raised from ground to prevent heating from ground reflected radiations.
10. Small Pinna(Ear)-Camels have small rounded ears located far back on the head covered with hairs to help keep out sand and dust
Physiological Adaptations
1. Plasma volume is maintained at the expense of tissue fluid, so that circulation is not impaired.
2. The small oval erythrocyte of the camel can continue to circulate in situations of increased blood viscosity.
3. Camels can take in a very large amount of water at one session to make up for previous fluid loss. In other animals, this would result in severe osmotic problems. Camels can do this because water is absorbed very slowly from their stomach and intestines, allowing time for equilibration. Furthermore, their erythrocytes can swell to 240% of normal size without bursting. (Other species can only go to 150 %.)
4. Their kidneys are capable of concentrating their urine markedly to reduce water loss. The urine can become as thick as syrup and have twice the salt content of sea water.
5. They can extract water from their fecal pellets so much that these can be used immediately for fuel upon voiding. Water loss via urine, feces and evaporation is reduced by a relatively efficient kidney, a capacity to recycle urea and an ability to maintain plasma volume.
6. A further adaptation solely for heat is involved in the camel’s ability to have a large fluctuation in body temperature (from 97.7 to 107.6 degrees F). During the day, its body acts as a heat sink, and during the cool night of the desert, excess body heat is dissipated by conduction.
7. One of the important physiological characteristics of camel is associated with its ability to continue lactation on low water inputs and on low quality diets.
8. Camels conserve nitrogen by recycling urea back into the fermentation structure of the gut and use high C:N ratio and maintain protein balance.
Camels are incredibly resilient to the desert climates and the arid conditions that would easily kill another animal. Camels also possess the incredible ability to lose nearly 40% of their body weight as water and be unharmed.
Opportunities:
Some of the steps for climate change adaptation described above involve more significant changes to current practice than others – some will require a major change to the thought processes involved with livestock management. However, there are a number of basic measures that require little change to best practice and should be considered as no-regret options: Species mixtures will provide some insurance against climate change – not all will be affected to the same extent. Provenance mixtures will provide insurance. Climate change predictions should be considered in the choice of livestock.
