A team of scientists from The University of Hong Kong is leading an international initiative to investigate the alarming decline of insect populations in tropical forests. Insects, the most abundant and diverse group of animals on Earth, are facing unprecedented threats in their natural habitats. This research effort, led by Dr. Michael Boyle and Professor Louise Ashton, aims to shed light on the status of tropical insects and the potential consequences of their decline.

Tropical rainforests, home to a staggering 75% of the world’s insect species, are under siege from urbanization, habitat loss, pollution, and climate change. Invasive species have decimated many unique island ecosystems, while rising temperatures and altered weather patterns disrupt crucial ecological processes. The scientists warn that these declines may have far-reaching consequences for ecosystem functioning, including changes in carbon cycling, pest outbreaks, and the spread of insect-vectored diseases.

Despite the relative lack of data from tropical forests, the researchers emphasize that recent advances in artificial intelligence and genetic methods are beginning to address these challenges. Over the past three years, the team has conducted extensive field research across tropical Australia and Asia, revisiting forests where insect studies were previously undertaken.

The ongoing research involves collecting ants, moths, beetles, and butterflies using specialized traps to assess how climate change has re-wired these populations over the last two decades. Similar studies are being carried out in Yunnan, China, and Daintree, Australia, including the use of tower cranes to collect insects from the rainforest canopy.

The team plans to study the ecological roles and functions of insect species to understand how changing populations will impact tropical forest ecosystems. They suspect that the important processes provided by beneficial insects, including regulating forest growth through herbivory and nutrient cycling, are dwindling over time.

“This review and our related projects highlight the issue of declining insect biodiversity in the tropics,” said Professor Louise Ashton. “We need more research, conservation efforts, and policy interventions to maintain tropical biodiversity and ensure the long-term health of these vital ecosystems.”

Southeast Asia’s fisheries have defied global trends by maintaining their ecological health and meeting the food needs of its growing population despite decades of warnings about overfishing. A recent study published in Fisheries Science has shed light on why this region is thriving against the tide.

The research, led by Professor Matsuishi Takashi Fritz at Hokkaido University’s Faculty of Fisheries Sciences, aimed to understand the status of Southeast Asia’s capture fisheries and identify lessons for other regions. The findings reveal that while global production has plateaued since 2018, Southeast Asia remains the top performer in terms of production growth over the past three decades.

However, this growth is not due to large-scale commercial fishing operations. Instead, it’s largely driven by small-scale and artisanal fisheries, which account for a significant portion of the region’s total catch. These small-scale fishers only take what they need for their local communities or families, as Southeast Asia has a high dependence on aquatic foods for protein.

Small-scale fishing has several advantages, according to Professor Fritz. It provides many jobs without overfishing, and the low-impact gear used by these fisheries helps preserve the ecosystem. The quality and freshness of the catch are also higher due to smaller quantities being caught at one time, which in turn fetches a relatively high price.

A unique feature of Southeast Asia’s capture fisheries is their ability to maintain biodiversity. Despite similar overfishing rates compared to the global average, the region has a three-fold higher ratio of underfished stocks than the global average. This means that there are more fish species being preserved in these waters, making it possible for multispecies fisheries to thrive.

To maintain this biodiversity, Professor Fritz emphasizes the importance of non-species-selective multispecies fisheries and management. Protecting, promoting, and controlling small-scale artisanal fisheries that do not destroy habitats is also crucial for preserving the region’s remarkable ecological health and food security.

The world’s rarest one-horned Asiatic rhinoceros has been the subject of intense study, revealing significant differences in appearance and behavior between two closely related species. A team of researchers, led by zoologist Francesco Nardelli and paleontologist Kurt Heißig, have shed new light on the Indian (Rhinoceros unicornis) and Sundaic (Rhinoceros sondaicus) rhinoceroses, challenging long-standing classifications and paving the way for a re-evaluation of their status.

The study highlights how millions of years of evolutionary pressures have shaped the distinct adaptations of these two species. The critically endangered Sundaic rhinoceros has a slender skull, a broader and lower back of the head, and a shorter nose and teeth suited for browsing leaves. In contrast, the Indian rhinoceros has a more robust skull and taller teeth adapted for grazing on grasses.

“The adaptations of large terrestrial mammals to various environments are linked to the diversity of food items they can consume, which is reflected in the variation of their dental and cranial morphologies,” the researchers write in their paper. “In rhinoceroses, these adaptations are identified in their teeth structure and head posture.”

The Sundaic rhinoceros, now confined to Java’s Ujung Kulon peninsula, is a browsing species with uniquely polygonal-patterned skin and hornless females. In contrast, the Indian rhinoceros is a grazer of riverine grasslands in northern India and Nepal, with deep skin folds and a heavier build.

Fossil evidence confirms that these differences evolved independently over a long period of time. The authors maintain that they represent fundamental anatomical and ecological distinctions and reflect deep evolutionary adaptations.

The behavior of the two species also differs significantly, with the Sundaic rhinoceros being solitary wanderers and Indian rhinoceros forming temporary crashes.

“Both species possess unique adaptations for survival, emphasising the importance of understanding their systematics for effective conservation,” the researchers write in their paper.

Based on these findings, the scientists propose a more precise scientific name for the Sundaic rhino: Eurhinoceros sondaicus. “Recognizing Eurhinoceros sondaicus as a distinct genus provides a more accurate reflection of its evolutionary history and ecological specialization,” they assert. “This refined classification not only enhances our understanding of rhinoceros evolution but also provides a clearer framework for conservation planning, helping to tailor strategies for the protection of these critically endangered animals.”