Tag Archives: nesting

Paleontologists Uncover Earliest Evidence of Ancient Honey Bees Nesting in Vertebrate Fossil

Posted on by
Reply

Bees exhibit an extraordinary range of species and behavior, from solitary types that nest in burrows to social variants that construct intricate nests. This nesting diversity is partially captured in the fossil record, with trace fossils dating from the Cretaceous to the Holocene. In a recent study, Field Museum paleontologist Lázaro Vignola López and his colleagues unveil novel nesting behaviors based on trace fossils unearthed from Late Quaternary cave deposits on the Caribbean island of Hispaniola. Osnidam Almontei was discovered within the cavity of a vertebrate corpse.

A reenactment of the life of bees with evidence of them building their nests in caves and using the bone cavities as housing chambers for several egg-laying cells. Image credit: Jorge Mario Macho.

“The initial descent into the cave isn’t very deep. You secure a rope to the side and rappel down,” Dr. Vignola López explained.

“Entering at night, you can spot the eyes of tarantulas residing there. As you navigate through the 10-meter-long underground tunnel, fossils start to emerge.”

Fossil layers were separated by carbonate deposits formed during rainy periods in antiquity.

Although rodents made up most of the fossils, remains of sloths, birds, and reptiles—over 50 species in total—were also found. Together, these fossils narrate a compelling story.

“We hypothesize this cave served as a home for owls over generations, potentially for hundreds or even thousands of years,” Dr. Vignola López remarked.

“The owl would venture out to hunt and return to the cave to regurgitate pellets.”

“We’ve collected fossils of the prey the owl consumed, its own remains, and even bones of turtles and crocodiles that may have inadvertently fallen into the cave.”

Dr. Vignola López and his colleagues observed that the sediments in empty tooth sockets of mammalian jaws didn’t accumulate randomly.

“The surface was notably smooth and slightly concave, which is unusual for sediment burial. I noticed this pattern across multiple specimens and thought to myself, ‘There’s something peculiar here.’ It reminded me of a hornet’s nest,” he noted.

Many well-known nests constructed by bees and wasps belong to social species that coexist in large colonies, raising their young together—like the bees in honeycombs or paper wasp nests.

“However, the majority of bee species are solitary. They deposit eggs in small cavities and leave pollen for their larvae’s nourishment,” Dr. Vignola López continued.

“Some bee species create nests in tree hollows, in the ground, or utilize vacant spaces. Certain species in Europe and Africa even nest within discarded snail shells.”

To investigate the possible insect nests within the cave fossils, the researchers conducted CT scans and X-rays of the bones, capturing 3D images of the compacted soil in the tooth sockets without damaging the fossils.

The shape and composition of the deposits bore similarities to mud nests created by some contemporary bee species. Some of these nests contained ancient pollen grains that mother bees had sealed for their larvae.

The researchers propose that bees combined saliva and soil to construct small nests for their eggs, smaller than the eraser on a pencil.

Nesting within larger animal bones provided protection for bee eggs from potential predators such as wasps.

While the bees themselves were not preserved, the unique characteristics of the nests allowed for a taxonomic classification.

They named the nests Osnidam Almontei, in honor of the scientist Juan Almonte Milan, who first discovered this cave.

“Since no bee remains were found, they may have belonged to a currently existing species. Our knowledge on the ecology of various bee species in these islands is limited,” Dr. Vignola López stated.

Scientists speculate that this behavior arises from a combination of factors. With little soil covering the limestone terrain in this region, bees may have opted for caves as their nesting sites, rather than digging into the ground like many other species.

Additionally, this cave had been home to generations of owls, with numerous owl pellets accumulating over the years, providing the bees with ample use of the bones the owls left behind.

“This finding illustrates the peculiarities of bees. They can be surprising, and it emphasizes the importance of meticulous examination when studying fossils,” Dr. Vignola López remarked.

of paper published today in Proceedings of the Royal Society B Biological Sciences.

_____

Lazaro W. Vignola-Lopez and others. 2025. Fossil traces in mammal remains reveal a new nesting behavior for bees. R Soc Open Science 12(12):251748; doi: 10.1098/rsos.251748

Source: www.sci.news

Fossils from 73 Million Years Ago Reveal the Earliest Evidence of Bird Nesting in Polar Regions

Posted on by
Reply

Polar ecosystems are bolstered and enriched by birds that nest there seasonally, serving as keystone members of these ecosystems. Despite the significant ecological role of polar birds, the origins of high-center nests remain unclear due to limited fossil evidence. A recent study conducted by paleontologists explored an extensive collection of bird fossils from the late Cretaceous Purine Cream Formation in Alaska.

Illustration of Cretaceous birds alongside other dinosaurs from the same period. Image credit: Gabriel Ugueto.

“Birds have existed for 150 million years,” stated Lauren Wilson, a doctoral candidate at Princeton University.

“For a significant portion of that time, they constructed nests in the Arctic.”

In their research, Wilson and colleagues studied the bones and teeth of fossilized birds from the Alaska Prune Creek Formation, dating back 73 million years.

They identified various bird types, including land birds, seagull-like birds, and diving birds that bear similarities to some modern ducks and geese, all of which were nesting in the Arctic while dinosaurs roamed the same territory.

Before this research, the earliest known evidence of breeding birds in the Arctic or Antarctic was approximately 47 million years ago, following the asteroid impact that wiped out 75% of Earth’s species.

“This will extend the timeline by 25-30 million years for records of birds breeding in the polar regions,” remarked Dr. Pat Druckenmiller, director of the University of Alaska Museum.

“The Arctic is recognized as a modern nursery for birds.”

“Finding bird bones from the Cretaceous period is exceptionally rare,” Wilson noted.

“Discovering baby bird bones is almost unheard of, making these fossils particularly significant.”

“We conducted extensive mapping of Alaska for fossil birds—it wasn’t on anyone’s radar,” added Dr. Druckenmiller.

“Now, we are one of the premier locations in the country for bird fossils from the dinosaur age.”

“Given the richness of this information, these small bones and teeth offer exceptional insights into the fauna from that era.”

It remains uncertain whether these newly discovered specimens are the earliest recognized members of Neornithes, a category that encompasses all modern birds.

Some of the newly unearthed bones exhibit skeletal characteristics exclusive to this group. Additionally, like contemporary birds, some did not possess true teeth.

“If they belong to a modern bird lineage, they would represent the oldest fossils ever found,” explained Dr. Druckenmiller.

“Currently, the oldest such fossils are about 69 million years old.”

“However, establishing that requires the discovery of a partial or complete skeleton.”

Survey results I will be featured this week in the journal Science.

____

Lauren N. Wilson et al. 2025. Evidence of bird nesting in the Arctic dates back to the Cretaceous period. Science 388 (6750): 974-978; doi: 10.1126/science.adt5189

Source: www.sci.news

Earliest Evidence of Ancient Birds Nesting Beyond the Arctic Circle

Posted on by
Reply

Illustration of an ancient bird nesting above the Arctic Circle

Gabriel Ugueto

Recent findings of bone fragments from Alaska indicate that birds have been nesting and breeding in the Arctic for at least 73 million years.

“It’s quite unusual, as raising a newborn in the Arctic is challenging,” explains study author Lauren Wilson from Princeton University.

Currently, around 250 bird species can thrive at the poles. Some migrate great distances to enjoy continuous daylight in summer, while others brave the winter, enduring extreme cold and long periods of darkness. However, knowledge about how these birds first adapted to the highest latitudes remains limited.

Wilson and her team searched for ancient avian traces within the Princreek Formation in northern Alaska, which formed on coastal floodplains about 73 million years ago. At that time, northern Alaska was approximately 1,000-1,600 kilometers closer to the Arctic than it is today.

The researchers retrieved ancient soil samples from several narrow rock layers, encountering temperatures of -30°C (-22°F) in a makeshift tent. “This has definitely been the most demanding fieldwork I’ve undertaken,” Wilson admits.

Back at the lab, they spent hours peering through microscopes at sediments smaller than two millimeters, hunting for tiny fossil bone fragments.

The team uncovered over 50 fossil fragments belonging to ancient birds, primarily from chicks and even embryos. The fossilized bones of these young birds exhibit a sponge-like texture, indicative of rapid bone growth.

Although birds likely began nesting in the Arctic Circle 73 million years ago, these fossils represent the earliest evidence of such behavior, extending the timeline of avian presence back by 30 million years.

However, many fossils are fragmented and do not clarify whether these birds remained year-round or only in the warm summer months.

“The Arctic’s food web, which supports life in extreme cold and darkness, couldn’t exist without the plethora of birds that inhabit high latitudes,” says Steve Brusatte from the University of Edinburgh, who wasn’t involved in the study. “These fossils illustrate that birds have been a vital part of these high-latitude ecosystems for tens of millions of years.”

Wilson’s team identified three major bird groups represented among the fossil fragments: extinct tooth-like birds similar to ducks, extinct tooth-like birds reminiscent of gulls, and various species that may be related to modern birds.

Conversely, the samples did not include bones from older bird groups known as enantiornithines, or “opposite birds.” Gerald Mayle from the Senckenberg Institute in Germany, who also wasn’t part of the study, noted that this finding suggests that more advanced bird ancestors could survive the harsh Arctic conditions due to certain evolutionary advantages that older birds lacked.

The ecosystems that shaped the Princreek Formation existed when non-avian dinosaurs dominated the planet, with evidence that ancient birds coexisted with species like tyrannosaurs and horned ceratopsians in these Arctic environments. Some dinosaurs even nested within the Arctic Circle.

Topics:

Source: www.newscientist.com