“From tuskless elephants to snails: how animals adapt to human activity Scientists have discovered unusual adaptations of animals to urbanization and human activity. Among the changes are the shorter wings of swallows, the pale shells of snails, and tuskless elephants in Africa.”, — write on: unn.ua
Some species move to colder waters or change their activity times, and plants adapt to urban environments. These changes show how human activity affects evolutionary processes.
This is reported by The Guardian, writes UNN.
Mahogany
Mahogany is known for its durability, resistance to decay and deep red wood, and it has become synonymous with luxury. They have been exterminated for their timber, so populations have declined by more than 70% in some countries. Although the old trees have largely disappeared, the species itself is still widespread in many areas. But now it grows in a slightly different form.
The species, now considered commercially extinct in many parts of its Caribbean range, still exists and is even common in some areas. But these young trees no longer grow tall and will never grow to the height for which the species was once famous
While the mahogany once grew up to 20 meters and sometimes more, the mahogany now exists as smaller shrubby trees that have no commercial value.
As the largest trees were cut down, they were unable to reproduce and share their diverse gene pool, which contributed to the species’ high growth.
Nests of magpies with spikes
Bird nests with spikes to deter predators are a common sight in cities. However, the researchers found that the magpies began to use the thorns, which were previously used to scare away birds, as building material for their nests. Postgraduate student Auke-Florian Hiemstra noted that this is part of a growing trend of birds using artificial materials for nests.
Stars who love beer bottles
First described in 2018, the species Astrophiura caroleae is a brittle star found at a depth of about 300 meters off the coast of Curacao. This pentagonal creature, a relative of the starfish, was collected underwater by Dr. David Pawson, curator of the Natural History Museum.
Scientists have found that this species successfully adapts to new environments, including discarded bottles and rubber tires. Dr. Hugh Carter notes that Astrophiura caroleae lives on hard substrates, particularly man-made objects.
Live specimens were observed only on discarded Heineken bottles at a depth of about 300 meters, which were probably thrown overboard by day fishermen. Interestingly, representatives of the genus are considered hard substrate specialists, so they mostly live on rocks, and it seems that this species quite successfully continues the tradition on man-made detritus
Snails with pale shells
A study of forest snails conducted by scientists in the Netherlands showed that snails living in urban environments have paler shells. Scientists associate this phenomenon with an increase in temperature in cities, which can be 8°C higher than in rural areas.
Professor Menno Schilthuizen notes that the pale color of the shell helps snails avoid overheating on hot summer days, as darker shells heat up more.
Swallows with shorter wings
A study of rock swallows in southwestern Nebraska found that the birds adapted to the risk of being hit by passing cars by evolving shorter wings. This allowed them to be more agile and avoid oncoming traffic. Birds with longer wings died more often because they could not maneuver as quickly.
Elephants without tusks
During the Mozambican civil war, massive poaching by militants led to a more than 90% decline in the population of African savannah elephants in Gorongosa National Park.
As populations are now recovering and represent one of the most important examples of global recovery, many elephants do not have tusks. According to the researchers, this is a consequence of the fact that tuskless elephants are less likely to become targets of poachers. The same change was recorded in Tanzania.
We will remind
Scientists from the USA and Chile discovered a new species of amphipod Dulcibella camanchaca in the Atacama Basin. The 4 cm predator preys on smaller amphipods and is the first active predator found at such a depth.