Conservation

Madagascar is a global biodiversity hotspot, with approximately 90% of all its plant and animal species being endemic, most of them associated with forest ecosystems. This rich biodiversity is threatened by relentless deforestation; in 2014 only about 15% of the national territory retained highly fragmented native forests, and deforestation continues with worrying forecasts for the coming decades. This rapid loss of habitat is not only causing species losses, but also the loss of important ecological functions that may disappear well before the extinction of the species involved. Here we want to draw attention to the three species of parrots endemic to Madagascar, for which there is a lack of systematically collected data on their distribution and population trends. We compiled available evidence, including data derived from citizen science, suggesting that the distribution and abundance of at least two of the three parrot species have declined in recent decades. These declines are likely driven not only by forest loss but also by persecution for the pet trade, crop protection, and hunting for food. There is also evidence, although still scarce, showing that these parrot species not only act as plant antagonists, but also fulfill mutualistic functions such as seed dispersal by different mechanisms, pollination, and maintenance of plant health. We urge researchers to study the current distribution and population size of the Malagasy parrots, as well as the full antagonism–mutualism spectrum of relationships with their food plants. This is needed for assessing their current conservation status, which may be significantly worse than that reflected by the IUCN Red List, and for identifying important ecological functions that may be lost before the disappearance of the species involved, which can be key to the maintenance and regeneration of the forests they inhabit.

This study examines a long-term dataset where 16 passerine species, classified as long-distance migrants, short-distance migrants, and residents were monitored at the Santo André National Ringing Station (Portugal) from 1997 to 2024. Using standardized capture data from 16 passerines species collected during the autumn migration period, we evaluated trends in population abundance over a 27-year time span. Our analyses revealed pronounced and statistically robust declines in all long-distance migratory species, particularly savi’s warbler, grasshopper warbler, and sedge warbler, which are now almost locally extinct. In contrast, short-distance migrants and resident species exhibited more heterogeneous patterns depending on their ecological specialization, yet all strictly insectivorous taxa, except for the chiffchaff, showed marked population declines, particularly the bluethroat and the sardinian warbler. The parallel decline in insectivorous species across migratory strategies points to a widespread trophic effect, likely linked to the global depletion of insect populations, driven by habitat destruction, pesticide use, pollution, and climate change. Collectively, these findings emphasize the urgent need for regionally adapted, long-term monitoring programs to inform effective conservation strategies in the face of accelerating climate and land-use change.

To establish the best approach for conserving a species, it is necessary to understand the biology of that species. To better understand the behavior of American black bears (Ursus americanus), we observed 246 black bears for 7950 h in nature over a 24-year period to quantify how the bears communicated. Black bears communicated using several different behaviors. These included thirteen types of vocalizations, eight olfactory behaviors, eight marking behaviors, sixteen different body postures and gestures constituting their body language, and various emotional expressions. Some behaviors appeared to be automatic, including facial expression, ear movements, some forms of body language, the intensity of various vocalizations, and various moans. Other behaviors appeared to be intentional, including mechanically generated sounds and actions that could be used to bluff or deceive, such as the chomping of teeth, huffing, swatting, false charging, and various vocalizations. The conservation of black bears can be improved by establishing management strategies that take into account the vocal and non-vocal communication of the bears. Conflicts and negative encounters between humans and bears can be reduced through behavioral modifications by humans based on our new understanding of the communication system of bears. Knowledge of the communication system of the black bear provides a basis for improved conservation through the non-lethal management of bears involved in bear–human conflicts.