Agriculture & Climate change, UK (Commonwealth Union) – In recent decades, forests worldwide have faced a growing threat known as fragmentation, which refers to the division of continuous forest landscapes into smaller, isolated patches due to various human activities. Fragmentation poses severe threats to biodiversity. When forests are fragmented, the habitats of numerous plant and animal species become smaller and isolated, limiting their ability to migrate, find mates, and access essential resources. This isolation can lead to genetic isolation, reduced genetic diversity, and increased vulnerability to diseases and other disturbances. Species that require large territories or exhibit specialized habitat requirements, such as large predators or migratory birds, are particularly affected by forest fragmentation. The loss of these keystone species can disrupt entire ecosystems. Defragmentation has been a procedure environmental scientists have applied particularly for endangered species that have been fragmented.
The simplicity for birds to fly between suitable areas has a strong impact on if a particular species is capable of surviving habitat fragmentation.
New research has demonstrated the reason tropical birds have a higher vulnerability to forest fragmentation, indicating that conservation policies are required to take into consideration the part of the climate in determining if animals can move across fragmented landscapes.
Due to logging and agricultural expansion splitting up forests across the globe, certain animals will be negatively impacted while others are capable of adapting. But the way each species responds will vary relying on a wide range of factors, like their diet, the local atmosphere, and the simplicity for them to bridge the gaps between the patches of natural habitat that are left.
Scientists have on prior occasions noticed that the sensitivity of birds to forest fragmentation relies on the latitude, with those in elevated latitudes performing better. A key theory behind this was that higher-latitude forests have undergone an ‘extinction filter’, which means that as the landscapes were degraded for lengthier periods the less-resilient birds have already become extinct.
New research that appeared in Nature Ecology & Evolution, which was led by Imperial College London however revealed that the extent to which bird wings are formed for gap-crossing has greater significance that impacts their capability of surviving habitat fragmentation.
Tom Weeks the 1st author of the study, from the Department of Life Sciences (Silwood Park) at the Imperial College of London, says “Our study confirms that forest fragmentation will have more severe effects on tropical species, and suggests that this pattern reflects inherent differences among species in their ability to cope.”
“One major implication for management of fragmented forests is that ‘corridors’ or ‘stepping stones’ of forest between larger intact areas are needed to increase connectivity and allow species to cope in these landscapes, particularly in the tropics.”
Researchers added together field survey data with a proxy for flight capabilities known as the hand-wing index (HWI). The HWI indicates the elongation of the wing, which has increased elongation in wings having greater adaptability for sustained flight, giving a rough estimation for the possibility of birds being able to move between habitat patches.
Prior studies from the team have indicated a gradient in dispersal ability, from low in close proximity to the equator to high at elevated latitudes. The dispersal capability was determined and was strongly forecasted to know if birds were scattered across variable seasonal climates.
Birds at lesser latitudes reside in climates with greater stability and hence look like they have adapted to an increasingly sedentary lifestyle, regularly guarding their territories throughout the year, with no requirement for migration. In comparison, birds at elevated latitudes have to be dispersive to monitor variability for atmospheric conditions as well as seasonal resources.
The new study takes this further by finding out the impacts of this gradient in reaction to forest fragmentation for 1,034 bird species across the world. Researchers discovered that sensitivity is more strongly forecasted by dispersal capabilities than other factors like latitude, body mass, together with historical disturbance.
