After the so-called El Niño of 1998, the skeleton of the sea iguana shrank due to a lack of food.
Off to the poles
Many wild animals migrate further from the equator as the temperature on earth rises. But migration can have major consequences for the survival of some species.
The planet is getting warmer and due to changing temperatures, more animals are suddenly in a climate where they are struggling to survive.
However, many species migrate to an area with a suitable temperature. British and Vietnamese scientists have followed the migration of more than 2000 species since 1970 by recording where they are now and comparing the data with earlier ones.
1690 m on average per year, all animals leave the equator.
It appears that animals and plants pull an average of 1690 meters away from the equator every year.
Animals that have reached their northernmost point in Antwerp at the moment can therefore be in Amsterdam in about 100 years. However, the researchers think that this speed is increasing because global warming is also expected to go faster in the 21st century.
Some animals are already a lot further than the average. The wild American turkey has moved 650 kilometers to the north, while the lobster along the Atlantic coast has come to live 500 kilometers closer to the North Pole.
But the massive emigration is not without consequences. When a species searches for new areas, it can lead to new food chains, loss of species and changing pollination processes.
New predators can also go to areas where prey animals are easy victims and will disappear.
Human activities force other types of behavior to change.Shutterstock
Man chases the animals into the dark
To minimize contact with humans, mammals shift their active hours into the dark - even if they are easy victims of hungry predators.
More and more mammals on earth are active at night and hide during the day.
This is apparent from a major study from 2018, in which researchers from the US followed the 24-hour rhythm of 141 groups of animals from 62 species from all continents (except Antarctica).
The researchers found that the time during which the animals were active at night increased by an average of 36 percent in areas where they could often come into contact with people during the day.
New evening animals
Boar rooting in the garbage and antelope hunters. A new study shows that many animals become more active at night.
Coyote does look out for walkers
Coyotes normally divide their waking hours over the day and night, but they are active at night 70 percent of the time along hiking trails in the Santa Cruz Mountains.
Sable antelope feeds hunters
Sable antelopes are normally only active during the day, but in the Hwange National Park in Zimbabwe they are now awake half nights to avoid hunters.
Wild boar is going to walk in Barcelona
Wild boar from the forests around Barcelona go into the city at night, where they are safe for hunters as they look for food in the residents' trash.
Species do this for various reasons, for example to gain access to food or to avoid hunters - but generally to minimize contact with people.
Changing the day and night rhythm is a well-known adjustment that prey animals have been using for millions of years to avoid the predators that are chasing them.
It is not bad that they now also follow this strategy for people, but it is further removed from their natural behavior.
That is why scientists expect that there will also be consequences for the group, for example what they eat and how they behave.
The nightlife brings the animals further in contact with new predators, which they must learn to deal with.
Animal boy earlier
Basses are more likely to have young, migratory birds leave earlier in the season and squirrels raise two litters of young each year. Animals adjust their mating time to survive.
Baars is more likely to be sexually mature
The bass in Lake Constance on the border of Switzerland, Germany and Austria are getting younger and sexually mature. The cause is the overfishing that the small predator has to deal with. With a high risk of being fished out of the lake, it is especially the fish that are early to mature and reproduce themselves quickly, who can pass on their genes.
Nectar forces hummingbird to nest earlier
In 2016, researchers found that many migratory birds in North America now nest earlier in the year. The cause is probably that the flowers bloom earlier due to climate changes, which means that birds that live on nectar, such as the ruby-throat hummingbird, have to reproduce earlier to get as much nectar as possible.
Squirrel raises two litters per year
Already in 2003 it turned out that the red squirrel in Yukon, Canada, genetically adapted to global warming. This had not been seen in mammals before. The little tree acrobat has brought his first litter early in 18 years with 18 days now that spring starts earlier. That way the animal can raise two litters before the fall.
After the so-called El Niño of 1998, the skeleton of the sea iguana shrank due to a lack of food.© Andrew Cooper / NaturePL
Animals are shrinking due to global warming
A large body needs a lot of food and oxygen, which is a disadvantage when it is hot. Many animals therefore become smaller in response to the heat.
German researchers on the Galapagos Islands have been tracking the size of marine iguanas for more than 25 years.
In 1998 they discovered that the animals had become lighter and shorter: their skeleton had shrunk.
The cause turned out to be a natural climate change, in which the water became warmer and the iguanas found it difficult to find food.
Now we know that many animals respond to heat by becoming smaller.The horse Sifrhippus shrank 30 percent due to the heat.
Prehistoric horse shrank 30 percent
To understand what happens to wild animals when the earth is 5 ° C warmer in 100 years' time, researchers look back 56 million years in time.
Then in 10,000 years time on Earth it became 8 ° C warmer, and the temperature did not return to its original level until after 175,000 years.
The response of many species was: shrink. Especially the horse Sifrhippus, which was no bigger than a big cat, became smaller.
The researchers can see from fossil teeth that the later mount animal first shrank by 30 percent because of the heat and then, when the weather became colder, almost doubled in size.Show more Show less
Fish enjoys toxic cocktail
Thanks to a rapid evolution, the tomcod has adapted to the environmental poison PCB.
Between 1947 and 1976, 600,000 kilograms of PCB, a heavy environmental poison, was discharged into the Hudson River near New York.
Pollution caused the entire ecosystem to collapse in the river, causing many species of fish and water birds to disappear.
Altered protein repels environmental poisons1 / 3
By changing the protein that PCB brings to the cell nucleus, the tomcod escapes the heaviest effects of the environmental poison.© Claus Lunau
The tomcod usually gets young from PCB with a deformed heart, but the approximately 35 centimeters long cod quickly adapted to its new environment and became 100 times less sensitive to the environmental poison.
The researchers already knew such an extreme and rapid adaptability, but the Atlantic tomcod is the first vertebrate to show this.