Mosquito Feeding Patterns Shift as Atlantic Forest Declines

A new scientific study conducted in remnants of Brazil’s Atlantic Forest has found that several mosquito species are feeding on humans more frequently as ongoing habitat loss reduces the availability of wildlife hosts.

Researchers working in two ecological reserves in the state of Rio de Janeiro collected more than 1,700 mosquitoes and analysed blood samples from engorged females. Their findings show that human blood was the most commonly identified source among the samples, surpassing birds, amphibians, and small mammals. According to the study, this shift appears linked to the shrinking forest ecosystem, which has lost much of its original biodiversity due to deforestation and human encroachment.

Scientists involved in the research noted that mosquitoes are highly adaptable and tend to rely on hosts that are most accessible. As wildlife populations decline or move away from disturbed habitats, humans become a more readily available blood source. “Mosquito behaviour is complex… host availability and proximity are extremely influential factors,” said senior author Dr. Jeronimo Alencar of the Oswaldo Cruz Institute.

The Atlantic Forest, once spanning a vast area along Brazil’s coastline, has been reduced to roughly one-third of its original size. This loss of habitat not only affects wildlife but also alters ecological interactions, including mosquito feeding behaviour. Public health experts warn that increased mosquito–human contact may heighten the risk of transmitting viruses such as dengue, Zika, yellow fever, and chikungunya in nearby communities.

Researchers emphasise that understanding mosquito foraging patterns is essential for anticipating changes in disease dynamics. As forest fragmentation continues, communities living near these ecosystems may face greater exposure to mosquito-borne illnesses, underscoring the need for sustained environmental protection and public health monitoring.