SOCIOBIOLOGY

Scarlet Macaw parents ‘play favorites,’ purposefully neglect younger chicks

Researchers at Texas A&M University have come to the rescue with a “foster program” for neglected chicks.

Texas A&M University

Scarlet macaws are a symbol of fidelity and virtue to many people because they are thought to mate for life — but it turns out that they also “play favorites” when feeding their young, making them excellent mates, but neglectful parents.

Fortunately, Texas A&M scientists have developed a way to ensure the birds’ bad parenting results in fewer chick deaths.  

Researchers at the College of Veterinary Medicine and Biomedical Sciences have discovered that scarlet macaws purposefully neglect feeding the youngest chicks in most broods, even when resources are plentiful. This results in only one or two chicks being able to fledge — the process in which parents teach their young to fly and survive on their own — even though broods may contain up to four chicks.

“Scientists have known for years that scarlet macaws hatch more chicks than they fledge,” said Dr. Donald Brightsmith, a professor in the VMBS’ Department of Veterinary Pathobiology. “We found that 26% of second chicks in scarlet macaw broods and nearly all third and fourth chicks die before fledging.

“We tested several theories as to why these younger chicks don’t survive, and we found that it’s not sibling rivalry or a lack of food. The parents just stop feeding certain chicks, so they starve to death,” he said.

The deciding factor appears to be the difference in chick ages.

“Scarlet macaws lay eggs over a period of several days instead of all at once, which means the chicks don’t hatch on the same day,” said Dr. Gabriela Vigo-Trauco, a post-doctoral researcher with the Schubot Center for Avian Health, who led the project. “If the second chick hatches only a couple of days after the first, there is a good chance that the parents will feed it. However, if it hatches four, five, or more days after the first chick, the parents will probably neglect it and let it die.”

The researchers, who recently published their study in the journal Diversity, suspect that when chicks are young and hatch four or more days apart, they begin to need different types of parental care. For example, some chicks need feeding while others are still incubating, which contributes to the high rates of neglect and starvation. 

Armed with this knowledge, the team has developed a method to save neglected chicks by giving them macaw “foster parents.”

“Thankfully, scarlet macaws are not endangered or threatened, but there are many parrot species that are,” Brightsmith said. “We hope that this foster program will be used to help save the populations of endangered parrot species.”

Understanding Brood Reduction

Brood reduction, or eliminating chicks after they hatch, is a common practice among birds.

“Some species of seabirds, like boobies, gulls, and pelicans, have a high degree of sibling rivalry that can lead to death,” Vigo-Trauco said. “Eagles, falcons and other species are known to attack and kill their own chicks. Often, parents target the smaller chicks, which are usually younger.”

For scarlet macaws, starvation is the cause of 45% of all chick deaths; chicks that hatch third or fourth in a brood always die.

“We wanted to understand what was causing 26% of second chicks to die of starvation,” Brightsmith said. “Scientists often point the finger at a lack of resources in the environment, but if it’s about conserving resources, then why do scarlet macaws lay so many eggs?”

To rule out lack of resources, Gustavo Martinez, a member of the research team, marked and monitored trees to estimate the amount of fruit — scarlet macaws’ main source of food — in the forests of the Tambopata National Reserve in Peru where the study was conducted. 

“Once a month for several years, he would go out and check about 1,300 trees for fruit and flowers,” Brightsmith said. “Looking at the data, we can tell that there were times when food scarcity forced macaws to forgo breeding for a season, but we couldn’t find any association with chick starvation.” 

Catching Macaws In The Act

To see what was happening in scarlet macaw nests, the researchers installed cameras in nest boxes at the Tambopata National Reserve in Peru. For 10 years, they captured video segments showing what was happening to the chicks. 

They also accessed the nests and manually checked which chicks had received food, which was how they determined that some chicks were intentionally being starved.

“Scarlet macaws have a food sac on their necks called a crop, and in chicks it’s very easy to see when it’s full of food,” Brightsmith said. “We caught video of female macaws trying to over-feed their oldest chicks while the third chick would be running slowly around the base of the nest with an empty crop, begging for food.  

“What’s more, the chicks at that age can’t regulate their own body temperature, so they need to be in the nest. We saw that the mother won’t even share her body heat with her dying offspring,” he said. “As scientists, we try not to do what’s called anthropomorphizing — attaching human ideas about morality to animals. But it’s hard to watch that and not think of it as parental abuse.”

The “abusive behavior” goes even further — but it seems that macaw parents aren’t always on the same page.

“Sometimes the female macaw will start to bury a chick that she’s decided not to feed by kicking nest substrate on top of it,” Brightsmith said. “But then the father will come home and unbury the chick and feed it. So, they’re not always in agreement, which makes the whole process even more complex.”

Saving Neglected Chicks

While scarlet macaws have some questionable parenting techniques for their own hatchlings, the good news is they also make excellent foster families for neglected chicks.

As part of her doctoral research, Vigo-Trauco developed a program for saving neglected chicks. The chicks are raised in captivity for a few weeks before being placed in the nests of macaws with chicks at a similar developmental stage or that have lost all their chicks to predation.

The program effectively eliminates the need for different types of parental care and allows the foster parents to raise chicks that would have starved. 

“The key to success is making sure that the chicks all look about the same size,” she said. “This encourages the new parents to take care of the foster chick as if it were their own.”

While the macaws seem to notice that something is different, that doesn’t stop them from adopting the foster chick.

“We see them on camera as they land on the nest box, look in, and then look around like they’re thinking, ‘Did I walk into the wrong house?’ It’s kind of hilarious,” Brightsmith said. “They turn their heads sideways to get a good look at the new chick, think about it for a moment, and then start to feed them.”

The foster chick program, published in Diversity in 2021, successfully re-homed 28 chicks over the course of three breeding seasons. 

“Parrots are one of the most endangered groups of birds in the world,” Brightsmith said. “We hope that this program, and the understanding of brood reduction behind it, can assist with the conservation of a broad array of parrot species across the tropics.”

By Courtney Price, College of Veterinary Medicine and Biomedical Sciences

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Journal

Diversity

DOI

10.3390/d16110657 

Method of Research

Observational study

Subject of Research

Animals

Article Title

Age Difference, Not Food Scarcity or Sibling Interactions, May Drive Brood Reduction in Wild Scarlet Macaws in Southeastern Peru

 

Bee gene specifies collective behavior

Bee research: publication in Science Advances

Heinrich-Heine University Duesseldorf

 

image: 

Each honeybee is labelled with a QR code so that their individual behaviour can be tracked. (Photo: HHU / Christoph Kawan)

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Credit: HHU / Christoph Kawan

Embargoed: Not for Release Until 2:00 pm U.S. Eastern Time Friday, 01 November 2024.

Researchers at Heinrich Heine University Düsseldorf (HHU) are collaborating with colleagues from Frankfurt/Main, Oxford and Würzburg to investigate how the complex, cooperative behaviour of honey bees (Apis mellifera) is genetically programmed so that it can be passed on to subsequent generations. As they explain in the scientific journal Science Advances, they found an answer in what is known as the doublesex gene (dsx).

Behavioural interactions between organisms are fundamental and often inherited. Every human being and every animal interacts with other individuals in its social group in one way or another through its behaviour. In the animal kingdom, this has considerable advantages in collective foraging for food, defence against predators and the rearing of offspring.

In some animals, such as honeybees, the social behaviour bonds are so strong that the individual members form a tight-knit society that function collectively as a single “superorganism”. Through their individual behaviour, thousands of worker bees protect the entire colony, feed it and care for the brood.

Professor Dr Martin Beye, who heads the Institute of Evolutionary Genetics at HHU and is the corresponding author of the study that has now been published in Science Advances, emphasises: “The behavioural repertoire of the individual bees and their function in the colony are not learned, but rather inherited. Until now, it was not known how such complex behaviours were genetically encoded.”

Together with colleagues from the universities in Frankfurt/Main, Oxford and Würzburg, the team of researchers at HHU led by Beye and first author Dr Vivien Sommer has now discovered that a special gene known as dsx specifies worker bee-specific behaviour.

Sommer: “The gene programmes whether a worker bee takes up a task in the colony and for how long. This includes collective tasks such as caring for the larvae or foraging for food and social exchanges on food sources, for example.”

The biologists used the CRISPR/Cas9 genetic scissors in their investigations to modify or switch off the dsx gene in selected bees. They attached a QR code to the manipulated bees, then monitored their behaviour in the hive with cameras. The resulting video sequences were analysed with the support of artificial intelligence to determine the bees’ individual behavioural patterns.

Sommer: “Our central question was whether and how the inherited behavioural patterns changed as a result of the gene modification. Such changes must be reflected in the nervous system of the worker bees where the specific behaviour is controlled.”

The researchers introduced green fluorescent protein (GFP) into the dsx sequence so that GFP was produced together with the dsx protein. The neuronal circuits could then be viewed using fluorescence microscopy, in both the unmodified bees and in those with genetic modifications. “We were able to use these tools to see exactly which neural pathways the dsx gene creates in the brain and how this gene in turn specifies the inherited behavioural patterns of honeybees,” explains doctoral researcher Jana Seiler, who is also a co-author of the study.

“Our findings indicate a fundamental genetic programme that determines the neuronal circuitry and behaviour of worker bees,” says Professor Dr Wolfgang Rössler from the Department of Behavioural Physiology and Sociobiology, who led the study at the University of Würzburg.

In the next step, the researchers now want to move from the level of the individual honeybee to the bee colony superorganism. Alina Sturm, who is also a doctoral researcher at HHU and study co-author, adds: “We hope to find the link between individual programming and the coordinated behaviour of many individuals.”

The neuronal network in the bee’s brain appears in green. (Image: HHU / Institute for Evolutionary Genetics)

Credit

HHU / Institute for Evolutionary Genetics

Original publication:

Vivien Sommer, Jana Seiler, Alina Sturm, Sven Köhnen, Anna Wagner, Christina Blut, Wolfgang Rössler, Stephen F. Goodwin, Bernd Grünewald, Martin Beye. Dedicated developmental programing for group-supporting behaviors in eusocial honeybees. Science Advances (2024).

DOI: 10.1126/sciadv.adp3953

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Journal

Science Advances

DOI

10.1126/sciadv.adp3953 

Article Title

Dedicated developmental programing for group-supporting behaviors in eusocial honeybees

Article Publication Date

1-Nov-2024

Camera tags capture social flexibility of Antarctic minke whales

TOO BAD THIS WON'T STOP JAPAN FROM HUNTING THEM FOR SUSHI

GRIFFITH UNIVERSITY

 

IMAGE: 

THE TEAM OF RESEARCHERS DEPLOYED TAGS TO THE ANTARCTIC MINKE WHALES THAT CAPTURED VIDEO AND AUDIO DURING THEIR INTERACTIONS.

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CREDIT: DAVE CADE

Researchers have conducted one of the first quantitative studies of social structure and social foraging in Antarctic minke whales (AMWs), using pioneering animal-borne camera tags.  

This study sheds light on the complex social and foraging behaviours of these elusive krill specialists within the fragile Antarctic sea-ice ecosystem. 

The study was led by Dr Jenny Allen as a Griffith University Research Associate in collaboration with the University of California Santa Cruz (UCSC).  Data were collected in 2018 and 2019 around the Western Antarctic Peninsula as part of a research grant from the National Science Foundation's Office of Polar Programs to Dr Ari Friedlaender, a Professor in UCSC’s Ocean Sciences Department.   

The study is unique in its use of motion-sensing, video- and audio-recording tags deployed on Antarctic minke whales for the first time to study their ecological role through analysis of their diving, foraging, and social behaviours. 

Data analyses focused on the whales' diving, foraging, and social behaviours, providing fresh insights into their ecological roles. 

Findings from the study indicated that Antarctic minke whales exhibit a "fission-fusion" social structure, frequently switching companions.  

This social flexibility is similar to what is seen in several other baleen whale species. In 60.6% of cases, whales were observed forming short-term associations, engaging in both foraging and non-foraging activities.  

Larger individuals were more likely to socialise, and this social interaction correlated with a noticeable reduction in their feeding efforts, regardless of dive depth. 

Furthermore, the study documented 12 instances where tagged whales associated with each other in pairs or trios.  

These groups demonstrated synchronised spatial movement and diving behaviours, suggesting that Antarctic minke whales employed group foraging strategies.  

Specifically, 67.5% of associated dives and 64% of associated feeding lunges were synchronised. 

"These findings provide essential baseline information on the sociality and group foraging behaviours of Antarctic minke whales," Dr Allen said.  

"Understanding these patterns is crucial, especially as climate change continues to impact the Antarctic ecosystem." 

The study underscored the importance of Antarctic minke whales as top krill predators, highlighting their role within the ecosystem.  

The synchronised foraging behaviour observed suggested these whales might optimise their feeding efficiency through cooperation, a behaviour previously underappreciated in this species. 

"This study is fascinating because it provides new information on complex and dynamic social and behavioural patterns by an animal that until now we had very little information about", says Dr. Friedlaender the senior investigator on the project. 

This research not only enhanced our understanding of AMW social and foraging ecology but also encouraged the need for future studies aimed at more targeted investigations.  

Dr Allen is currently a National Science Foundation Postdoctoral Fellow at UCSC within the Behavioural Ecology and Bio-Telemetry Laboratory and an Adjunct Researcher with Griffith University’s Southern Ocean Persistent Organic Pollutants Program.  

The study ‘Evidence of sociality and group foraging in Antarctic minke whales (Balaenoptera bonaerensis)’ has been published in Behavioral Ecology and Sociobiology, and was supported by the National Science Foundation's Office of Polar Programs via grant nos. 1643877 and 1644209, and by World Wildlife Fund grants. P0710 and 0711-02. 

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JOURNAL

Behavioral Ecology and Sociobiology

DOI

10.1007/s00265-024-03481-4 

ARTICLE TITLE

Evidence of sociality and group foraging in Antarctic minke whales (Balaenoptera bonaerensis)

 

Desert ants: the magnetic field calibrates the navigation system

Peer-Reviewed Publication

UNIVERSITY OF WÜRZBURG

 

IMAGE: 

THE DESERT ANT CATAGLYPHIS NODUS AT ITS NEST ENTRANCE - AN INCONSPICUOUS HOLE IN THE GROUND THAT CANNOT BE SEEN FROM THE ANT'S PERSPECTIVE. TO FIND ITS WAY BACK THERE, THE ANT USES THE EARTH'S MAGNETIC FIELD DURING ITS LEARNING WALKS.

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CREDIT: ROBIN GROB

They are only a few centimeters tall and their brains have a comparatively simple structure with less than one million neurons. Nevertheless, desert ants of the Cataglyphis genus  possess abilities that distinguish them from many other creatures: The animals are able to orient themselves to the Earth's magnetic field.

Visible Changes in the Nervous System

A research team from Julius-Maximilians-Universität Würzburg (JMU) discovered this a few years ago. However, it was previously unknown where in the ants' brains the magnetic information is processed. This has now changed: In a new study published in the journal PNAS - Proceedings of the National Academy of Sciences, the team shows that information about the Earth's magnetic field is primarily processed in the ants' internal compass, the so-called central complex, and in the mushroom bodies, the animals' learning and memory centers.

Professor Wolfgang Rössler, holder of the Chair of Behavioral Physiology and Sociobiology at the University of Würzburg, Dr. Pauline Fleischmann, former scientist at the Chair of Behavioral Physiology and Sociobiology and now a member of the Neurosensorics/ Animal Navigation working group at the University of Oldenburg, and Dr. Robin Grob, who has since moved from Rössler's chair to the Norwegian University of Science and Technology in Trondheim, were responsible for this study.

First Exploratory Walks for Calibration

"Before an ant leaves its underground nest for the first time and goes in search of food, it has to calibrate its navigation system," says Pauline Fleischmann, explaining the background to the work. During so-called learning walks, the animals then explore the immediate surroundings around the nest entrance and repeatedly pirouette around their own body axis with short stops in between. During these pauses, they always look exactly back in the direction of the nest entrance, even though they cannot see it – a tiny hole in the ground.

Thanks to their field studies in southern Greece, where Cataglyphis ants are native, Fleischmann and her colleagues were able to prove that desert ants orient themselves to the Earth's magnetic field during the learning walk phase. Pauline Fleischmann and Robin Grob were once again on site in Greece. This time, however, they not only investigated the ants' orientation behavior while the magnetic field was being manipulated, but also looked for changes in the nervous system of Cataglyphis as an expression of the newly acquired experience.

A Faulty Magnetic Field Disrupts the Learning Process

The zoologists concentrated on young workers that had not yet undertaken any learning walks. The animals were only allowed to set off as part of the precisely planned experiments – sometimes under natural conditions, sometimes in a permanently manipulated magnetic field that, for example, displayed chaotic directions or did not allow horizontal orientation. With this faulty directional information, it was not suitable as a reliable reference system for the ants' behavior to look back to the nest entrance during the learning walks.

The result: "Our neuroanatomical brain analyses show that ants exposed to an altered magnetic field have a smaller volume and fewer synaptic complexes in an area of the brain responsible for the integration of visual information and learning, the so-called mushroom body," explain Fleischmann and Grob. In the central complex, the region of the ant’s brain in which spatial orientation is anchored, the same findings were observed under certain conditions.

The Number of Synaptic Connections Increases

Desert ants that were allowed to make their first excursions under natural conditions were clearly different. Their sensory experiences, a combination of information about the magnetic field, the position of the sun and the visual environment, triggered a learning process that was accompanied by structural changes in the neurons and an increase in synaptic connections in the aforementioned brain regions.

According to the scientists, this leads to the conclusion that magnetic information not only serves as a compass for navigation, but also as a global reference system that is crucial for the formation of spatial memory.

In Search of the Sensory Organ

The results of their experiments prove "that ants need a functioning magnetic compass during their learning walks in order to calibrate their visual compass and at the same time store images of the nest environment in their long-term memory", as Pauline Fleischmann and Robin Grob say. At the same time, their research extends far beyond the field of compass calibration in ants. Wolfgang Rössler emphasizes that "the results provide valuable information on how multisensory stimuli can influence neuronal plasticity of brain circuits for navigation in a critical phase of brain maturation."

In a next step, the team now wants to investigate in which sensory organ the desert ant receives the magnetic information and via which sensory pathways it is transmitted and processed. This has not yet been achieved with any animal species that orients itself to the Earth's magnetic field. Due to their manageable and relatively small nervous system, insects, to which Cataglyphis belongs, offer a unique opportunity to investigate the neuronal basis of magnetic orientation at all levels.

The research team used a 3D Helmholtz coil system to manipulate the earth's magnetic field around the nest entrance.

CREDIT

Robin Grob

Confocal microscope image of the central area in the brain of the desert ant Cataglyphis nodus. The paired mushroom bodies, which are responsible for sensory integration, learning and memory, can be seen on both sides. In the middle between the mushroom bodies is the central complex, a brain structure responsible for orientation in space.

CREDIT

Wolfgang Roessler

JOURNAL

Proceedings of the National Academy of Sciences

DOI

10.1073/pnas.2320764121 

METHOD OF RESEARCH

Observational study

SUBJECT OF RESEARCH

Animals

ARTICLE TITLE

Importance of magnetic information for neuronal plasticity in desert ants

ARTICLE PUBLICATION DATE

12-Feb-2024

SOCIOBIOLOGY

A pair of brain regions prompts females to kill or care for their young

Peer-Reviewed Publication

NYU LANGONE HEALTH / NYU GROSSMAN SCHOOL OF MEDICINE

A middle-brain region tied to the control of emotions likely prompts females to kill their young, a new study in mice shows. With the region also present in humans, the study authors say the findings could play a similar role in better understanding infanticide by women.

Before giving birth for the first time, female mice are known to often kill others’ pups. This behavior may have evolved to preserve scarce food supplies for their own future offspring, according to experts. However, most studies have focused on infanticide by adult males, and the brain mechanism behind this behavior in females has until now remained poorly understood.

Led by researchers at NYU Grossman School of Medicine, the study showed that chemically blocking the region, called the principal nucleus of the bed nucleus of stria terminalis (BNSTpr), prevented infanticide nearly 100% of the time. By contrast, when the study team artificially activated the brain region, both mothers and females without offspring killed pups in nearly all trials, attacking within a second of the stimulation. The mice rarely attacked other adults, the authors say, suggesting that the structure specifically controls aggression toward young animals.

The investigation also revealed that the BNSTpr appears to work in opposition to a brain region called the medial preoptic area (MPOA), itself known to promote mothering behavior. According to the findings, mice that had not yet reached motherhood showed high BNSTpr activity, which dampened activity in the MPOA. After the mice gave birth, however, MPOA activity ramped up, likely suppressing the infanticidal system in the process. The new mothers tended to avoid infanticide regardless of whether the pup was theirs.

“Our investigation pinpoints for the first time the brain mechanisms that we believe encourage and discourage infanticide in females,” said study lead author Long Mei, PhD, a Leon Levy Foundation postdoctoral fellow in NYU Langone Health’s Neuroscience Institute.

The new study, publishing online June 7 in the journal Nature, also demonstrates that the switch to maternal behaviors can be reversed by extra pressure to the BNSTpr, notes Mei.

According to the U.S. Centers for Disease Control and Prevention, child abuse is the fourth leading cause of death among preschool children in the United States. Mei notes that while early studies had largely focused on potential problems in the parenting centers of the brain, experts have more recently begun to search for a separate system dedicated to infanticide and aggression against children.

For the investigation, researchers first narrowed down the most likely brain regions behind infanticidal behavior by tracking which structures were connected to the MPOA. Next, they artificially stimulated each of the resulting seven areas in live mice to determine which, if any, caused the animals to attack pups. Then, the team blocked activity in the BNSTpr, the most promising candidate remaining, to see if this would prevent infanticide.

To demonstrate that the BNSTpr and MPOA counteract each other, the study authors prepared brain slices from female rodents and activated one region while at the same time recording cell activity in the other. They also traced how activity in these structures changed as rodents reached motherhood.

“Since these two connecting regions in the middle of the brain can be found in both rodents and humans alike, our findings hint at a possible target for understanding, and perhaps even treating, mothers who abuse their children,” said study senior author and neuroscientist Dayu Lin, PhD. “Maybe these cells normally remain dormant, but stress, postpartum depression, and other known triggers for child abuse may prompt them to become more active,” added Lin, a professor in the Departments of Psychiatry and Neuroscience and Physiology at NYU Langone.

That said, Lin, also a member of NYU Langone’s Neuroscience Institute, cautions that it remains unclear if the two brain regions perform the same roles in humans as they do in rodents.

She adds that the study team next plans to examine the BNSTpr and MPOA in male mice and to explore ways of turning off activity in the former region without invasive surgery.

Funding for the study was provided by National Institutes of Health grants R01HD092596, R21HD090563, R01MH101377, and U19NS107616. Additional funding was provided by the Leon Levy Foundation.

In addition to Mei and Lin, other NYU study investigators involved in the study were Rongzhen Yan, PhD; Luping Yin, PhD; and Regina Sullivan, PhD.

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JOURNAL

Nature

DOI

10.1038/s41586-023-06147-9 

METHOD OF RESEARCH

Experimental study

SUBJECT OF RESEARCH

Animals

ARTICLE TITLE

Antagonistic circuits mediating infanticide and maternal care in female mice

ARTICLE PUBLICATION DATE

7-Jun-2023

KATYDIDS

Radio tracking reveals greater predation risk for female bushcrickets

Peer-Reviewed Publication

INDIAN INSTITUTE OF SCIENCE (IISC)

 

IMAGE: A WHISTLER MALE WITH RADIO TAG ATTACHED view more 

CREDIT: KASTURI SAHA

Just like humans, animals move about to find food, shelter, and mates. Movement in the wild, however, comes with increased risk, as it can be tracked by predators. 

To understand how katydids (bushcrickets) are hunted by their predator – the lesser false vampire bat – a group of researchers led by Rohini Balakrishnan, Professor at the Centre for Ecological Sciences (CES), Indian Institute of Science (IISc), fitted tiny radio tags onto these insects and tracked their movement in the canopy. They found that female katydids are at greater risk than males, likely because the former are frequent fliers who cover longer distances.  

Published in Behavioral Ecology and Sociobiology, this is the first insect radio tracking study in India, explains Harish Prakash, postdoc at CES and an author of the paper. He says that in addition to field observation, they carried out experiments in a controlled environment to answer key research questions on predator-prey interactions. 

Lesser false vampire bats – native to South and Southeast Asia – bring their prey back to their roost to eat. A large proportion of the bat diet consists of insects like katydids. In earlier studies, Balakrishnan and others found that there were a lot more remnants of female wings than males, suggesting that the bats preferred to prey on female katydids. This was unexpected, because katydid females are usually silent, unlike the males that make themselves conspicuous by calling out to attract the females. This led the researchers to ask the question: What about katydid females made them more attractive to the bats? 

One possibility is that bats can detect females more easily, since they are usually larger than males. Second, female katydids might be more nutritious than males and therefore preferred by bats. To test these possibilities, the researchers focused on a group of katydids called “whistlers”, in which females are almost double the size and weight of the males. They presented free-flying whistler females as well as males to bats in a large, outdoor cage. Surprisingly, the bats approached both males and females with equal frequency. In fact, in this experimental setup, females escaped capture more often than males. So, it was not the size or nutritive value of the females that increased the risk of their predation. 

Then the researchers hit on a third possibility: perhaps the females were flying out more often. To test this, the team glued tiny radio transmitters onto the backs of male and female katydids and tracked them as they flew across trees. What they found was that females tend to move 1.5 times more frequently and 1.8 times farther than males. This led them to conclude that flying more frequently and traveling longer distances across trees may put females at a higher risk of being hunted by bats than males. Kasturi Saha, PhD student at CES and corresponding author on the paper, suggests a possible reason for these frequent long flights: “The females may move around in search of mates, as well as suitable egg-laying sites.” 

“In systems where males produce conspicuous acoustic signals and females move silently, it has been assumed that males rather than females perform the higher-risk behaviours,” says Balakrishnan. However, contrary to this view of risk-taking males and risk-averse females, the current study shows that female katydids might be at greater risk of predation.  

There are still many unanswered questions about the predator-prey interactions. For example, Saha explains that the bats seem to hunt more female katydids during non-breeding seasons. “This is another mystery we are trying to solve.”

Lesser false vampire bat

CREDIT

Kasturi Saha

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JOURNAL

Behavioral Ecology and Sociobiology

DOI

10.1007/s00265-023-03298-7 

ARTICLE TITLE

Is flying riskier for female katydids than for males?

SOCIOBIOLOGY; STEP PARENTS ABUSE

California megachurch leader, grandparents charged with murder, torture in death of 11-year-old daughter

Natalie Neysa Alund, USA TODAY - 

A California megachurch leader and her parents have been arrested on charges including murder and torture in the death of the woman's 11-year-old daughter.

Leticia McCormack, a leader at Rock Church in San Diego, founded and led by former NFL player Miles McPherson, was booked in jail on Nov. 7. 2022 on charges of murder and in connection to the death of Arabella McCormack, her 11-year-old daughter pictured here.© San Diego County Sheriff's Department.

Leticia McCormack, a leader at Rock Church in San Diego, founded and led by former NFL player Miles McPherson, was booked in jail Monday on a charge of murder, three counts of torture, and three counts of willful cruelty to a child in the death of Arabella McCormack, the San Diego County Sheriff's Office reported.

On Thursday, McCormack's leadership profile had been removed from the megachurch's website.

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Arabella was initially fostered before being adopted by Brian and Leticia McCormack, officials said.

The 49-year-old church elder's father, Stanley Tom, 75, was also charged with murder, three counts of torture, and three counts of willful cruelty to a child, according to a news release from the department. Arabella's grandmother Adella Tom, 70, was booked on three counts of torture and three counts of willful cruelty to a child.

'Severe levels of malnourishment'

On Aug. 30, deputies responded to a child-in-distress call at a home in Spring Valley, in the eastern part of the county, where they found Arabella, according to the news release.

The 11-year-old was rushed to a hospital, where her health declined and she died, officials reported, according to the release. Detectives said they suspected child abuse.

The girl was covered in bruises and had suffered "severe levels of malnourishment," a police spokesperson told The San Diego Union-Tribune.

During the investigation, deputies contacted the girl's father, Brian McCormack, near the family's home. According to the release, he died by suicide in their presence.

Arabella had two sisters, ages 6 and 7, the release says, who are now living with a foster family.

On Thursday afternoon, a Rock Church spokesperson told USA TODAY that Leticia McCormack began volunteering with the Rock Church in 2013 and has helped in various capacities, including administrative tasks and helping coordinate events and other ministry activities.

The spokesperson also said that her ordination at Rock Church was previously suspended and as of Thursday was in the process of being revoked.

The church also released the following statement to USA TODAY:

"We continue to grieve for Arabella and her sisters. We are so sorry that their family and friends are experiencing this unimaginable loss and pain. We send our deepest condolences to all that are grieving at this time. Our hearts go out to each of them.

The legal process will run its course and we hope justice for Arabella and her sisters will be served. We are praying that God’s love and grace will bring comfort and healing.

The Rock no longer has any official relationship with Leticia."

The sheriff's department could not immediately be reached by USA TODAY Thursday.

Are Stepchildren at Higher Risk for Abuse Than Biological Children?

April 9, 2013 • 

By A GoodTherapy.org News Summary

According to sociobiology, genetic preservation is at the core of human behavior. Because it is inherent in our genetic structure to ensure survival, individuals are predisposed to take measures to guarantee their genetic survival. In other words, they favor strategies and methods that will increase the likelihood of their family lineage being carried on. This is done through positive and negative methods. Positively, people have children so that their genetic tree can be extended to further generations. Negative methods of preserving genetic lineage also exist and include violence and aggression toward people who are not blood relatives. Based on these theories, it could be assumed that stepchildren are more likely to be abused by parents than biological children. In fact, some research has provided evidence of a 5-fold increase in risk of child abuse for step-children compared to biological children.

There is abundant evidence that children living in stepfamilies are more likely to experience sexual abuse. And children living with unmarried parents are also at risk for abuses including physical, sexual and emotional abuse. However, it has not been clearly established if stepchildren are injured as a result of their abuse more often than biological children. To get a better look at abuse rates among biological and stepchildren, Stewart J. D’Alessio of the Deaprtment of Criminal Justice at Florida International University recently examined data from more than 130 cities that was used as part of a larger study on abuse incident reporting. He looked at the biological status of the children, as well as the socioeconomic condition of their environment, as it has been suggested that disadvantaged communities have higher levels of stepchildren abuse.

D’Alessio found that children living in disadvantaged communities were more likely to experience abuse than those in socioeconomically advanced environments. He also found that the age of the perpetrator was influential of abuse. Younger parents were more likely to abuse children than older parents. However, there was no evidence suggesting that stepchildren were at increased risk for injury. “Contrary to expectations,” said D’Alessio, “Our results showed that the effect of a child’s genetic status on the likelihood of physical injury was in the opposite direction as predicted by sociobiology.” In fact, the stepchildren were less likely to be physically injured than the biological children. D’Alessio notes that these findings raise more questions for future research, and that that exploration should consider that many incidents of abuse are never reported. Methods to ascertain more reliable and valid abuse rates should be investigated in future work in this area.

Reference:
D’Alessio, Stewart J., PhD, and Lisa Stolzenberg. (2012). Stepchildren, community disadvantage, and physical injury in a child abuse incident: A preliminary investigation. Violence and Victims 27.6 (2012): 860-70. ProQuest. Web.

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Violence against children by stepparents PDF

• April 2020

• In book: The SAGE Handbook of Domestic Violence   
• Publisher: SAGE

Abstract

A wide range of child and caregiver characteristics, including parental psychopathology, parents’ childhood experiences of abuse, parenting stress, child age, parent age, child disabilities, socio-cultural background, and caregiver’s relationship to the child, have been reported to contribute to increased risk of violence directed against children. Although there is a dearth of research into violence against children in stepfamilies, some studies have indicated that stepparents are more likely to abuse children compared with genetic parents. Stepparents also have been found to pose a significantly greater risk of using excessive violence, which can subsequently lead to the death of a child. The risk of violence against stepchildren has also been found to be significantly elevated with the presence of stepparent’s genetic offspring. One possible explanation for increased violence in stepfamilies is that stepparents do not want to invest feelings and resources in children who do not carry copies of their genes. Sexual violence by stepparents, on the other hand, can be explained by the lack of exposure to a learning mechanism termed ‘incest aversion’, which refers to negative sexual imprinting during a critical period of early childhood to avoid inbreeding. Yet another possibility is that people who divorce are more likely to do so due to aggressive impulses which can play a part in relationship termination. When they remarry, those aggressive impulses can be directed against stepchildren. However, stepfamilies are also reported to experience more stressors associated with family violence, including alcohol abuse, child’s behavioral problems, adverse contextual backgrounds, and weaker social networks. This suggests that the stepfamily structure may not be a risk factor of violence against children per se. The purpose of this chapter is to provide a description of the problem of violence against children by stepparents, discuss the extent of the phenomenon and its possible theoretical explanations, critically review empirical research assessing violence against children by stepmothers and stepfathers, as well as suggest directions for future research.