Monday, April 20, 2026

Birds caught stealing from their neighbors

Branch bandits pose a hidden threat to native species

University of California - Riverside

image:
ʻIʻiwi bird in Hawaii.
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Credit: Jessie Knowlton/UCR

High in the forests of Hawai‘i, songbirds are stealing twigs and moss from one another’s nests. UC Riverside researchers found this quiet canopy crime is surprisingly common and could threaten species already struggling to survive.

A new study led by Erin Wilson Rankin, UCR entomologist, offers a detailed look into nest-material theft among Hawaiian forest birds, a behavior known as kleptoparasitism. While scientists have long noted such theft anecdotally, this is the first time it’s been tracked and quantified in the wild.

“People working in the field have seen this behavior for years, but it’s never been documented at this level,” Wilson Rankin said. “Now we can say who’s doing it, who they’re stealing from, and what happens to the nests afterward.”

Over six months, a trained team observed more than 200 nests belonging to native canopy-nesting birds, including the scarlet I‘iwi, the crimson Apapane, and the yellow-green Hawai‘i Amakihi. The Apapane emerged as both the most frequent thief and the most common victim, likely due to its abundance in the forest.

Most theft occurred between nests built at similar heights in the trees, supporting what the researchers call the “height overlap hypothesis.” Birds may be pilfering from nests they happen upon while foraging.

In most cases, the nests targeted had already been abandoned. But in about 10% of thefts, the nests were still active, either being built or holding eggs or chicks. Of those, some ended in failure.

“We saw instances where nests failed, either because the nest structure was compromised or because the parents were disturbed and left,” Wilson Rankin said. Roughly 5% of the observed nests failed after a theft.

While that may sound like a small percentage, Wilson Rankin said it raises red flags for species already under stress due to habitat loss, disease, and climate change. In combination with threats like avian malaria, subtle risks like this could accelerate population decline.

The study, published in The American Naturalist, also sheds light on the thieving birds themselves. Though stealing may reduce the energy and time needed to build a nest, it’s not without potential costs. Stolen materials could carry parasites or disease, and some bird species are known to defend nests aggressively, though Hawaiian birds, the researchers noted, are generally peaceful.

“What’s fascinating is that this behavior is happening within species as well,” Wilson Rankin said. “Apapane were stealing from other Apapane.”

Wilson Rankin, who began this research while studying forest arthropods, collaborated with her husband, UCR biologist David Rankin, who led the nest-finding efforts. Their shared goal was to gather detailed life-history data on Hawaiian birds of conservation concern.

Although none of the species in the study are endangered, they are part of a shrinking group of native birds being pushed into higher elevations by mosquito-borne diseases introduced by humans. Conservationists worry forests like these, which were once safe havens, are becoming increasingly crowded and competitive for birds.

“This kind of behavior could be more common if nesting materials or safe nesting sites become scarce,” Wilson Rankin said. “It’s something we should measure.”

Understanding which birds are most vulnerable, and under what conditions kleptoparasitism is most likely to occur, could help scientists design better conservation strategies as habitat continues to fragment.

“If we can predict when and where this behavior happens, we might not be able to stop it, but we can intervene in other ways to support at-risk species,” Wilson Rankin said. “That’s a benefit of this work.”

She hopes the study also encourages researchers to take a second look at everyday wildlife behaviors that might seem trivial, like stealing a twig, but could carry weighty consequences.

“Sometimes threats to animal species don’t come from predators or people,” Wilson Rankin said. “They can come from similar animals.”

UC Riverside biologist David Rankin searching for birds' nests in Hawaii.

Credit

Jessie Knowlton/UCR

Journal

The American Naturalist

DOI

10.1086/740144

Article Title

Upcycling in the Hawaiian Islands: Native Forest Birds Commonly Engage in Nest Material Kleptoparasitism

Article Publication Date

18-Apr-2026

Egyptian mummy remains examined at Semmelweis University

Semmelweis University

Egyptian female mummy head — image:
Egyptian mummy remains were examined at Semmelweis University’s Medical Imaging Center (OKK). The archeological finds arriving from the Semmelweis Museum of Medical History, Hungarian National Museum Public Collection Centre (MNMKK) were analyzed using the institution’s newest CT scanner equipped with a photon-counting detector. Thanks to state-of-the-art imaging technology, highly detailed images have been captured that were previously unavailable, and the initial results promise significant scientific advances.
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Credit: Image by Medical Imaging Center - Semmelweis University, Budapest, Hungary

Egyptian mummy remains were examined at Semmelweis University’s Medical Imaging Center (OKK). The archeological finds arriving from the Semmelweis Museum of Medical History, Hungarian National Museum Public Collection Centre (MNMKK) were analyzed using the institution’s newest CT scanner equipped with a photon-counting detector. Thanks to state-of-the-art imaging technology, highly detailed images have been captured that were previously unavailable, and the initial results promise significant scientific advances.

In accordance with standard clinical practice, the examination of the mummy remains was conducted outside of patient examination hours, at night. This technology is particularly effective at analyzing complex, multilayered materials, including the non-destructive, detailed analyses of mummified human remains. “The aim of the examinations is to obtain as accurate a picture as possible of the internal structure of the remains, any abnormalities, and the preservation techniques used,” said Dr. Ibolyka Dudás, Chief Clinical Physician at the Department of Radiology and Head of the working group for post-mortem imaging.

Over two-thousand-year-old finds under CT scan

The Egyptian mummy remains currently under examination were added to the collection of the MNMKK Semmelweis Museum of Medical History around the time of its founding. In recent years, the finds in question have been repeatedly subjected to various imaging and multidisciplinary examinations, including conventional CT scans. However, due to technological constraints, these did not allow for a sufficiently detailed assessment. Six specimens were subjected to radiocarbon (C14) dating, but only three yielded measurable results. Based on this, the oldest remains can be dated to between 401 and 259 BCE, meaning they are more than 2,300 years old. As part of the current series of examinations, this specimen and all of the museum’s other Egyptian mummy remains have undergone new analysis.

Novel opportunities for more accurate diagnosis

The recent high-resolution CT scans allow for a more detailed examination of the teeth and skull sutures of the two mummified heads. This could lead to a more accurate age determination and lay the groundwork for future high-precision, detailed 3D reconstructions, as well as potential facial reconstructions of the skulls.

In the case of a previously examined left lower limb, it was not possible until now to establish a definitive diagnosis; however, based on the new images, several possible interpretations have emerged. The current examinations indicate that the individual may have suffered from osteoporosis; however, the exact cause – whether due to age-related factors or a pathological process – requires further, detailed analysis.

An examination of the second lower left limb revealed that the remains likely belong to a young individual. The exact age is still being determined, but this is the first time such detailed imaging data has become available for this find.

The examination of a set of remains – previously interpreted merely as a mummy bundle – yielded particularly noteworthy results. When the find arrived at the museum, in the absence of imaging tests, it was initially identified as a human head and later, possibly, as a bird mummy. However, a previous CT scan clearly showed that the find is, in fact, an adult foot. The current imaging analysis aims to determine the extent to which the textile remnants can provide insight into the mummification technique, the age of the mummified individual, and any illnesses the individual may have had. The current images clearly reveal the different layers of the bandage and show their different structural characteristics. These findings may lay the groundwork for further historical and technological investigations. The remains were presumably part of a complete mummy, but the reason and time of the dissection are currently unknown.

The analysis of the mummified hand included in the study can also offer valuable information. Based on the size, development, and morphological characteristics of the bones, researchers aim to determine whether the remains belonged to a child or an adult. They may also be able to estimate the individual’s sex and age.

Cutting-edge technology in the service of mummy research

“The remains had previously been examined by a research team, but the current images provide a more detailed view than ever before and are expected to yield new, scientifically valid findings regarding the remains that have been preserved in the collection for decades,” emphasized the collection’s curator, Chief Museologist Krisztina Scheffer.

A detailed evaluation of the images is currently underway. Researchers expect the data analysis to provide new insights into the mummies’ lives and state of health, as well as the mummification process.

“Based on the results so far, it is evident that modern imaging technology opens up new perspectives in mummy research. It can reveal information hidden in finds that are thousands of years old without damaging them,” added the chief curator.

Egyptian mummy hand — Egyptian mummy remains were examined at Semmelweis University’s Medical Imaging Center (OKK). The archeological finds arriving from the Semmelweis Museum of Medical History, Hungarian National Museum Public Collection Centre (MNMKK) were analyzed using the institution’s newest CT scanner equipped with a photon-counting detector. Thanks to state-of-the-art imaging technology, highly detailed images have been captured that were previously unavailable, and the initial results promise significant scientific advances.
Egyptian mummy remains were examined at Semmelweis University’s Medical Imaging Center (OKK). The archeological finds arriving from the Semmelweis Museum of Medical History, Hungarian National Museum Public Collection Centre (MNMKK) were analyzed using the institution’s newest CT scanner equipped with a photon-counting detector. Thanks to state-of-the-art imaging technology, highly detailed images have been captured that were previously unavailable, and the initial results promise significant scientific advances.

Egyptian mummy remains were examined at Semmelweis University’s Medical Imaging Center (OKK). The archeological finds arriving from the Semmelweis Museum of Medical History, Hungarian National Museum Public Collection Centre (MNMKK) were analyzed using the institution’s newest CT scanner equipped with a photon-counting detector. Thanks to state-of-the-art imaging technology, highly detailed images have been captured that were previously unavailable, and the initial results promise significant scientific advances.

Egyptian mummy remains were examined at Semmelweis University’s Medical Imaging Center (OKK). The archeological finds arriving from the Semmelweis Museum of Medical History, Hungarian National Museum Public Collection Centre (MNMKK) were analyzed using the institution’s newest CT scanner equipped with a photon-counting detector. Thanks to state-of-the-art imaging technology, highly detailed images have been captured that were previously unavailable, and the initial results promise significant scientific advances.

Egyptian mummy remains were examined at Semmelweis University’s Medical Imaging Center (OKK). The archeological finds arriving from the Semmelweis Museum of Medical History, Hungarian National Museum Public Collection Centre (MNMKK) were analyzed using the institution’s newest CT scanner equipped with a photon-counting detector. Thanks to state-of-the-art imaging technology, highly detailed images have been captured that were previously unavailable, and the initial results promise significant scientific advances.

Egyptian mummy remains were examined at Semmelweis University’s Medical Imaging Center (OKK). The archeological finds arriving from the Semmelweis Museum of Medical History, Hungarian National Museum Public Collection Centre (MNMKK) were analyzed using the institution’s newest CT scanner equipped with a photon-counting detector. Thanks to state-of-the-art imaging technology, highly detailed images have been captured that were previously unavailable, and the initial results promise significant scientific advances.

Longer reproductive span linked with slower rates of cognitive decline

New large-scale study documented a significant association between endogenous estrogen-exposure history and better cognitive function in older women, but a longer duration of hormone therapy did not contribute to positive outcomes

The Menopause Society

CLEVELAND, Ohio (April 15, 2026)—Cognitive decline not only affects a woman’s quality of life but also her ability to lead an independent lifestyle later in life. A new large-scale study suggests that a longer reproductive lifespan, resulting in greater exposure to endogenous estrogen, is associated with better cognitive health. Results of the study are published online today in Menopause, the journal of The Menopause Society.

Cognitive decline can be considered a preclinical marker of dementia. Women experience faster cognitive decline than men, and it is hypothesized that sex hormones may contribute to this disparity. Reproductive span, defined as the time between age at menarche and age at menopause, represents an important aspect of natural estrogen exposure, although previous studies found inconsistent results between reproductive span and cognition. Studies on the effects of hormone therapy on cognition have also yielded conflicting results.

Given these inconsistencies in prior research regarding reproductive span and timing of hormone therapy initiation on cognitive decline, this new study used more than 30 years of prospectively collected data from more than 14,000 women to evaluate reproductive span, age at menarche, age at menopause, and surgical menopause and their associations with cognition. The results confirmed that a longer reproductive span is associated with better cognitive maintenance. However, hormone therapy use within 10 years of menopause showed no cognitive benefits.

Survey results are published in the article “Prospective study of reproductive span and menopausal hormone therapy and cognitive decline over 8 years in the Nurses’ Health Study.”

“This large observational study showed an association of longer reproductive span with better cognitive trajectories. However, longer duration of hormone therapy use, either within or outside 10 years of menopause, was not associated with better global cognitive performance. Although the results of this well-designed study may still be affected by residual confounding, they support current guidelines that recommend against the use of hormone therapy for prevention of dementia,” says Dr. Stephanie Faubion, medical director for The Menopause Society.

For more information about menopause and healthy aging, visit www.menopause.org.

The Menopause Society is dedicated to empowering healthcare professionals and providing them with the tools and resources to improve the health of women during the menopause transition and beyond. As the leading authority on menopause since 1989, the nonprofit, multidisciplinary organization serves as the independent, evidence-based resource for healthcare professionals, researchers, the media, and the public and leads the conversation about improving women’s health and healthcare experiences. To learn more, visit menopause.org.