A bird was eaten a 3,000 meters high: it’s the highest case of bird predation in the world. The discovery occurred during research led byUniversity of Amsterdam (Netherlands).
The prey is a gray plover of the species Pluvialis squatarola and the predator is probably a peregrine falcon. The reconstruction took place thanks to a GPS tag that researchers had placed on the victim (and 7 other similar birds) in January 2023 to study their migration across northern Europe, with the aim, in particular, of understanding why these birds migrate at such high altitudes.
A theory that a part of the scientific community espouses states that these peaks are reached precisely because of this avoid predation. In fact, these rare events generally occur when birds stop to rest. Although some specialized predators are known for catch birds while they are in flightbut research on this is scarce.
The clues
At 9.58pm local time on May 27 (25 minutes after sunset) – the researchers write – one of the marked birds suddenly its migratory flight was interrupted. At the same time, the body acceleration signal of the tracking device on this plover experienced a sharp drop, and two minutes later (i.e. at 10 pm), GPS was recorded at an altitude of approximately 2900 m above the level of sea
And it didn’t end there. In fact more information from this tag was in stark contrast to the previous ones: in particular, a change in course from 64° (NE) to 194° (SW) and a decrease in flight speed from 14.4 ± 4.1 m/s to 6.4 m/s were shown, while the subsequent detection GPS at 00:00 on May 28 and all subsequent readings were from a single location 8 km away. The bird was later recovered by the team, who also discovered the remains of the gray plover.
The reconstruction
The remains of the victim’s body were found a short distance from a peregrine falcon nest, and prior to the time of death, the tag recorded increased body acceleration approximately 15 minutes before the collapse was recorded. The authors therefore suggest that the plover may have seen its attacker coming and therefore attempted to fly faster to escape.
Peregrine falcons are in fact the fastest birds in the world, reaching speed of 320 kilometers per hour when divinguseful when feeding on a diet of other birds. For this reason, scientists believe that it is precisely that peregrine falcon that has preyed on the gray plover, potentially making this event the highest altitude bird predation case ever recorded.
Why do these birds fly so high during their migrations
The question was the one scientists asked themselves when they discovered predation. Part of the scientific community believes that this is done for avoid overheatingbut not everyone is of the same opinion, indeed, there are those who think that the strategy is implemented precisely for escape from predation.
Although the risk of predation is considered to be important evolutionary factor of migration strategies – the authors write – its role in modeling flight altitudes remains only speculative (…). Our observation suggests that this may not always be the case, as increasing flight altitude up to 3000 m above the ground
The study is published Ecology.
Source: Ecology
