Tag Archives: raptor

Raptor birds around the world are in decline, as they struggle with habitat loss and poisoned foods

Birds of prey are declining all throughout the world, according to new research, putting the health of ecosystems at risk. Habitat destruction is the main driver of this decline.

Image via Pixabay.

The paper analyzed data from the International Union for the Conservation of Nature (IUCN) and BirdLife International, a global partnership of non-governmental organizations involved in the conservation of birds and their habitat. Overall, the data showed that around 50% of the 577 bird of prey (raptor) species worldwide are declining in number. Roughly 30% are threatened, vulnerable, endangered, or critically endangered, with 18 species falling into the latter category.

Several species are also at risk of becoming locally extinct, even if they’re faring relatively okay as a whole species, the team explains. This means that they would no longer be able to act as top predators in certain ecosystems, a role critical for ecosystem health.

Bird issues

“The golden eagle is the national bird of Mexico, but we have very few golden eagles left in Mexico,” said Gerardo Ceballos, a bird scientist at the National Autonomous University of Mexico and co-author of the study.

The main threat to these birds is habitat destruction, the team explains, both through the direct issues it creates for them, such as a lack of adequate nesting areas, increased in-species competition for space and resources, as well as through indirect effects, including lower populations of animals that serve as prey.

Over half of raptor birds that are most active during the day (54%), including most hawks, eagles, and vultures, are showing ongoing population declines. Nocturnal raptors are faring somewhat better, with only 47% of species in this category showing population decline. This showcases that birds are experiencing strong pressures right now, not past pressures that have affected their numbers but have been addressed in the meantime. In other words, affected species will only fare worse over time, and it’s possible that new ones will also start being affected unless action is taken.

Apart from habitat destruction, other leading causes for the decline of raptors highlighted in the study include compounds such as rodent poison, used in agriculture, and lead shot that is typically used for hunting birds. Raptors routinely feed on rodents and carrion, so these compounds inadvertently affect them. Heavy use of anti-inflammatory drugs in livestock is also propelling the rapid decline of raptors, through the same mechanism. This is an issue particularly in South Asia, where some species have declined by 95% in recent decades due to the consumption of livestock carcasses.

The paper lists 4,200 sites previously identified by conservation groups as being essential for the health of raptors globally. According to the team, most of these are not protected in any way, or only enjoy partial coverage by protected areas. To illustrate how this state of affairs can impact raptor communities over a wide geographical range, the authors give East Asia as an example. Raptor species here tend to breed in north China, Mongolia, or Russia, and then migrate down the eastern coast of China to spend summers in Southeast Asia or India.

Multiple species will thus travel through a handful of sites throughout their migrations, so issues in any one of them will have wide-ranging impacts. Eastern China, for example, is very densely populated and highly urbanized, so sites in this area are facing massive pressures from human activity, including habitat destruction and contamination with agricultural compounds.

The paper “Global patterns of raptor distribution and protected areas optimal selection to reduce the extinction crises” has been published in the journal PNAS.

Paleontologists find 10-meter-long megaraptor in Argentina

It’s not just football that Argentina is famous for. The country is packed with dinosaurs’ fossils, with 80 species found so far in its territory. That’s 10% of the 800 that have been discovered across the world. Half of all known species have been found in Argentina, the US, China, and Mongolia. Now, a new species has been added to the roster.

Artist impression of a megaraptor. Credit Wikipedia Commons

Following two weeks of excavations, a group of paleontologists found a new megaraptor in the south of Argentina, specifically in the province of Santa Cruz. The specimen measured about 10 meters (33 feet) in length, which makes it one of the largest megaraptors found so far.

In a statement, the team said that the remains date back 70 million years – towards the end of “the age of the dinosaurs”. Fernando Novas, who was involved in the excavations, told Reuters news agency that “this new megaraptor that we now have to study would be one of the last representatives of this group” before the dinosaurs became extinct.

Megaraptors were large predatory dinosaurs that prospered during the Cretaceous period, primarily in the southern hemisphere (remains were also found in Australia and Asia) until the mass extinction that happened approximately 65 million years ago.

“Unlike the Tyrannosaurus rex, the megaraptors were slimmer animals, more prepared to run, with long tails that allowed them to maintain balance. They had muscular legs to be able to take long steps,” said in a statement Mauro Aranciaga Rolando, a fellow at the Argentine Museum of Natural Sciences (MACN).

Megaraptors had several characteristics that made them particularly lethal. According to Aranciaga, their main weapons were their extremely long and muscular arms. They also had claws on their thumbs, which had a sharp edge and could reach 40 centimeters in length.

Researcher Fernando Novas said that this new discovery will allow paleontologists “to know how these dinosaurs were in this corner of Patagonia and to know their relationships with the megaraptors found in other parts of the world.” Novas discovered the first specimen of this group of dinosaurs in 1996 and gave them their name.

The smallest specimens of megaraptors so far found measured about five meters, while the largest reached lengths similar to this specimen found in Argentina. To extract the fossils, which were locked in extremely hard rock, it was necessary to use appropriate machinery such as a rock cutter.

In a task that took about two weeks, with chisels and hammers, paleontologists removed the rock surrounding the specimen in order to remove each of the fossilized bones. The rock that contained the fossil was covered with plastic and bandages and transported to Buenos Aires, the capital of Argentina.

The formidable predator is now under quarantine at the Natural Sciences Museum in Buenos Aires, waiting for the researchers to continue with their preparation and study. After being fully described, the fossils will make their trip back to the province of Santa Cruz to enrich the collections of the “Padre Molina” Museum.