Unusually high temperatures across India are disrupting the natural cycles of plants and wildlife
Scientists report early flowering, delayed bird nesting and altered behaviour among amphibians and reptiles
Ecologists warn that seasonal mismatches between species could have long-term impacts on ecosystems
Heat stress, drying water bodies and early forest fires are compounding the risks for wildlife
India’s unusually warm late winter and early spring have begun to alter the behaviour of plants and animals across the country, scientists say, raising concerns about the long-term ecological impact of shifting seasonal patterns.
February and early March felt more like peak summer months in several regions this year. Globally, February was recorded as the fifth warmest on record. In India, Delhi experienced its warmest March in nearly 50 years, while parts of the Himalayas did not witness the expected winter cold waves.
But it is wildlife and vegetation that appear to be facing the sharpest consequences. Scientists say temperatures in some areas have risen between 5 degrees Celsius (°C) and 12°C above normal, disturbing natural cycles of flowering, breeding and migration.
Across India, researchers report changes in behaviour among plants, birds, amphibians and reptiles.
Manzoor Shah, a botanist and professor at the University of Kashmir, says the Himalayan region has witnessed an unprecedented rise in temperatures. “Temperatures that one would usually see in April are now felt during early March or February,” he says. “This year’s February temperature has broken a 35-year-old record.”
According to Shah, the unusual warmth has triggered early flowering in several plant species that normally bloom later in the season. Among them are Viburnum grandiflorum, Iris reticulata, species of Narcissus and Sternbergia.
The university has been monitoring more than 200 species for many years to track phenology — the timing of seasonal biological events — and their functional traits.
Observations show flowering is taking place around 20 to 25 days earlier than usual, said Shah. Such shifts can have wider ecological consequences. Pollinators such as bees often rely on seasonal cues to time their activity, and when plants flower earlier than expected, those interactions can fall out of sync.
“Early flowering means the bees and other pollinators are not yet active,” Shah explains. “This mismatch can lead to flowers shedding early, leaving little nectar and food for pollinators, which may result in mortality and long-term population decline.”
In central India, ornithologists say rising temperatures are already affecting the nesting and breeding patterns of several bird species. Satish Pande, a Pune-based ornithologist and director of the Ela Foundation, says the months between January and March are typically breeding periods for many birds of prey and other species.
These include raptors such as hawk eagles, Bonelli’s eagles and short-toed snake eagles.
“Normally nesting begins around December,” he says. “But this year we observed nesting being delayed until the end of January.”
Such delays can have cascading effects. If eggs hatch later than usual, the chicks may emerge during the hottest part of the season.
Pande says this could push hatching towards the end of March, when temperatures in many regions approach peak summer levels. At the same time, the flowering cycles of trees that provide nectar and food for birds have also shifted.
Trees such as the Flame of the Forest and the red silk cotton tree bloomed early in March this year rather than in April. By the time the birds’ eggs hatch, the flowering may already have ended, reducing food availability for adult birds and their chicks.
The heat has also begun to affect bird habitats.
Water bodies in several areas have started drying earlier than usual, making them less suitable for both resident and migratory species. Some migratory birds have already begun departing, while shortages of food and water during this critical period are causing concern.
“Heat is also taking a toll on birds which are becoming dehydrated and exhausted,” Pande says. “In recent days we have rescued Indian robins, tailorbirds, house sparrows, bulbuls, grey francolins and quails.”
Early forest fires, some started by human activity, have compounded the problem. According to Pande, fires reported earlier than usual this year have destroyed nests of ground-nesting birds such as larks and the Indian eagle owl, whose eggs were still waiting to hatch in grasslands.
The unusually high temperatures are also affecting amphibians and reptiles, particularly species that depend on stable humidity and temperature levels.
Madhushri Mudke, a conservation scientist at the Ashoka Trust for Research in Ecology and the Environment (ATREE), says field observations in Maharashtra suggest amphibians are already adapting their behaviour to cope with the heat. During a visit to Sindhudurg district in November 2025, Mudke and her colleagues found frogs belonging to the Indirana genus taking refuge inside caves.
“The outside temperatures we measured were around 28°C, compared to the roughly 22°C that is comfortable for them,” she says.
Across the tropical belt, higher temperatures can adversely affect specialist species that rely on stable temperatures and humidity, Mudke said. Amphibians are particularly vulnerable because their permeable skin makes them highly sensitive to environmental conditions.
“They rely on environmental moisture to regulate body temperature,” Mudke explains. “Heat waves can quickly affect their physiology and behaviour.”
She notes that even in November, evergreen forest areas in the region had received little rain. In response, many amphibians appeared to have shifted into survival mode. They sought refuge in cooler locations such as dense canopy areas or small caves.
Mudke says her team documented several amphibian species using caves as shelter during the drier season in Sindhudurg.
Her more recent field visit to the Chorla Ghats in February revealed a similar pattern.
“We didn’t find many frogs during our study,” she says. “It is possible they were hiding elsewhere, or that other factors are affecting them which we do not yet fully understand.”
Reptiles may also be affected by changing weather patterns, though scientists say more research is needed to understand the long-term effects.
Ishan Agarwal, a scientist with the Thackeray Wildlife Foundation, says most reptiles breed in early summer and their young are typically born between the pre-monsoon and post-monsoon period. “But we need long-term scientific studies to fully understand how changing weather patterns will impact different reptile groups,” he says.
Insects and agricultural pests are also responding to the heat, sometimes in unexpected ways.
Abhishek Pareek, a research officer in the entomology department of Rajasthan’s agriculture department, says unusually high temperatures have killed large numbers of mustard aphids — pests that typically damage mustard crops. Temperatures this season were around 3-4°C higher than normal.
“This has benefited mustard crops because pest losses were reduced,” Pareek says. “The entire generation of aphids could not survive the high temperatures.”
However, the effects are not entirely positive. Many other insects depend on aphids as part of the food chain. With their primary food source gone, those species may also suffer population declines.
“The natural enemies or host insects that rely on aphids for food have also died,” Pareek explains. “Food simply became unavailable.”
While these isolated events may not always signal long-term change, repeated disruptions to seasonal cycles could reshape ecological systems in the years ahead.