A new study conducted in the Mojave Desert shows that desert birds suffer more than mammals from rising temperatures.
The increase in average temperatures is causing damage to more or less all living species on the planet. However, the impact of the climate crisis is not the same for everyone; and the more we go on to study how ecosystems are responding to the emergency; the more we discover that there are groups that fare better and others that are in the midst of an existential crisis.
The latest sensational example comes from California, in particular from the Mojave desert; a study published in Science, which began in the early twentieth century and ended only in recent years; shows that the inhabitants of the desert are reacting to rising temperatures in a very different. In fact, the birds have declined rapidly in the last century, the mammals continue to get by without major problems.
We cheated in part when talking about a study that began in the early twentieth century. The new research dates for the past two years. It is based on data collected at the beginning of the last century by naturalist Joseph Grinnell. From the time of Grinnell to today, the average temperature of Mojave has increased by about 2 ° C. The team led by the ecologist Eric Riddell of the Iowa State University compared the current populations with those of a century ago; making use of documentation exterminated.
In the past few years, two studies showed that some desert bird species in the Mojave are in decline due to rising temperatures. The study by Riddell and colleagues confirms this trend. However, it also reveals that small mammals are not experiencing global warming in the same way – indeed.
Faced with a decline in the diversity of desert bird species which in some areas reaches 40%. Mammals (in particular smaller ones such as rats, mice, and chipmunks) are doing very well. Of the 34 species considered, three are in decline, 27 are stable and four are even in numerical growth.
IT DEPENDS ON THE HABITS OF THE DESERT BIRDS
According to the study, birds need to spend three times as much energy as mammals to maintain a stable temperature. The difference is due to the habits of life; while the birds studied spend most of the day exposed to the sun; the small mammals spend it underground, where it is cooler, and return to the surface only at night. It is no coincidence that the only three declining mammal species are those that live in areas. These areas have flat grounds and do not provide enough shade to hide during the day.