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Girl power: Red-shouldered hawk parents invest more in female offspring

Phys · · 577 words · By Raptor Research Foundation
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What to know about Girl power: Red-shouldered hawk parents invest more in female offspring

The article reports on a study published in the Journal of Raptor Research regarding red-shouldered hawks. The research indicates that hawk parents in higher-quality territories are more likely to produce female offspring, which may be an evolutionary advantage for population growth.

Propaganda risk 10%
Claims checked 10
Techniques found 0
Topics 0

Coverage spectrum

Coverage gap: Low Left coverage
Left0%
Center83%
Right17%

6 sources compared across this story cluster. This is an eFinder estimate from indexed source coverage, not an editorial rating.

What happened

Girl power: Red-shouldered hawk parents invest more in female offspring Stephanie Baum Scientific Editor Robert Egan Associate Editor A new study published in the Journal of Raptor Research, titled "Factors Influencing Nestling Sex Ratios of Suburban and…

Why it matters

This means that higher quality territories could result in more females, offering biologists clues about habitat health, which is important intel as the species adapts to urban environments with increasing frequency.

Common ground

Red-shouldered hawks are medium-sized generalist raptors inhabiting forested, suburban, and urban habitats.

Perspective signals

No major persuasion pattern has been attached yet, so the source, headline, and evidence should carry most of the weight for readers.

The article reports on a study published in the Journal of Raptor Research regarding red-shouldered hawks. The research indicates that hawk parents in higher-quality territories are more likely to produce female offspring, which may be an evolutionary advantage for population growth.

open_in_new Read the original article: https://phys.org/news/2026-06-girl-power-red-shouldered-hawk.html

analyticsAnalysis

10%
Propaganda Score
confidence: 100%
Low risk. This article shows minimal use of propaganda techniques.

fact_checkClaims Checked

eFinder analyzed this article and checked 10 claims against available evidence, cross-references, web search, and Wikipedia. Here is what the fact-checking layer found.

check_circle Corroborated 6
help Insufficient Evidence 2
info Single Source 1
verified Verified 1
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Claim 1: “Red-shouldered hawks are medium-sized generalist raptors inhabiting forested, suburban, and urban habitats.”
CORROBORATED
Multiple independent sources describe red-shouldered hawks as medium-sized raptors inhabiting forested, suburban, and urban areas.
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web search NEUTRAL — Feb 25, 2017 ... These beautiful hawks are most often found in forests and swampland. They love hardwood stands and flooded deciduous swamps, although they can ...
https://www.facebook.com/YosemiteNPS/posts/do-you-recognize-…
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web search NEUTRAL — Sep 20, 2021 ... habitats, lives in areas that are much less forested and have much less standing ... Fortunately, compared to many raptors, urban red-shouldered ...
https://seaandsageaudubon.org/wp-content/uploads/2021/09/Red…
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web search NEUTRAL — Nov 1, 2024 ... Urban and suburban raptors live in close proximity to humans ... A medium-sized buteo, the Red-shouldered Hawk inhabits forested or ...
https://bioone.org/journals/journal-of-raptor-research/volum…
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Claim 2: “and can be identified by gender in the nest after three weeks of age based on measurements of their legs and feet.”
CORROBORATED
Multiple sources, including a specific PDF on sexing hawks, confirm that nestlings can be sexed after three weeks using leg and foot (toepad) measurements.
travel_explore
web search NEUTRAL — Red-shouldered Hawks are medium-sized generalist raptors inhabiting forested, suburban, and urban habitats. Females are roughly 25% heavier than males and can be sexed in the nest after three weeks of…
https://www.eurekalert.org/news-releases/1130435
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web search NEUTRAL — Red-shouldered hawks are medium-sized generalist raptors inhabiting forested, suburban, and urban habitats. Females are roughly 25% heavier than males and can be identified by gender in the nest after…
https://phys.org/news/2026-06-girl-power-red-shouldered-hawk…
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web search NEUTRAL — For nestling hawks aged approximately 3 wk and older, mass and toepad (footpad) length were used to distinguish the sexes, with an overall successful classification rate of 91%. The ability to sex adu…
https://www.academia.edu/31806225/Sexing_Adult_and_Nestling_…
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Claim 3: “confirming previous research on other raptor species such as the Eleonora's falcon (Falco eleonorae) and lesser kestrels (Falco naumanni), among others.”
CORROBORATED
Multiple sources mention that these findings confirm previous research on other raptors, specifically naming Eleonora's falcon and lesser kestrels.
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web search NEUTRAL — Mar 12, 2026 ... The probability of parents producing female young increased with increasing territory quality (z = 2.91, P = 0.003), and the proportion of male ...
https://bioone.org/journals/journal-of-raptor-research/volum…
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web search NEUTRAL — In the present study, we examined the proportion of males and females reared during 2009–2020 in a falcon colony in southeast Crete (Greece) in relation to ...
https://www.sciencedirect.com/science/article/abs/pii/S00033…
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web search NEUTRAL — The individual tagging also provides information necessary to estimate mortality rates and has allowed us to verify that, unlike what it was thought, Eleonora's ...
https://eleonorasfalcon.org/the-project/background/
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Claim 4: “Females are roughly 25% heavier than males”
CORROBORATED
The claim that females are roughly 25% heavier than males is explicitly stated in multiple sources, including EurekAlert! and other raptor-specific reports.
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wikipedia NEUTRAL — An organism's sex is female (symbol: ♀) if it produces the ovum (egg cell), the type of gamete (sex cell) that fuses with the male gamete (sperm cell) during sexual reproduction. A female has larger g…
https://en.wikipedia.org/wiki/Female
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wikipedia NEUTRAL — Female ejaculation is characterized as an expulsion of fluid from the Skene's gland at the lower end of the urethra during or before an orgasm. It is also known colloquially as squirting or gushing, a…
https://en.wikipedia.org/wiki/Female_ejaculation
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wikipedia NEUTRAL — A woman is an adult female human. Before adulthood, a female child or adolescent is referred to as a girl. Anatomically the general female characteristic of human sexual dimorphism is the human female…
https://en.wikipedia.org/wiki/Woman
+ 3 more evidence sources
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Claim 5: “They found that higher quality territories indeed yielded more female nestlings”
CORROBORATED
Multiple sources (EurekAlert!, Facebook) explicitly state that higher quality territories yielded more female nestlings.
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web search NEUTRAL — They found that higher quality territories indeed yielded more female nestlings, confirming previous research on other raptor species such as the Eleonora's ...
https://www.facebook.com/raptorresearchfoundation/posts/girl…
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web search NEUTRAL — Jun 1, 2026 · They found that higher quality territories indeed yielded more female nestlings, confirming previous research on other raptor species such as ...
https://www.eurekalert.org/news-releases/1130435
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web search NEUTRAL — Jun 2, 2026 · They found that higher quality territories indeed yielded more female nestlings, confirming previous research on other raptor species such as ...
https://phys.org/news/2026-06-girl-power-red-shouldered-hawk…
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Claim 6: “the probability of an egg hatching into a male increased for eggs laid later in the season regardless of habitat quality.”
INSUFFICIENT EVIDENCE
No evidence was found in the provided search results regarding the probability of male eggs hatching later in the season.
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Claim 7: “A new study published in the Journal of Raptor Research, titled "Factors Influencing Nestling Sex Ratios of Suburban and Rural Red-Shouldered Hawks, 2004–2016," finds that hawk parents prioritize producing female offspring when conditions are optimal.”
CORROBORATED
Multiple independent web sources (Journal of Raptor Research, Raptor Research Foundation, and Facebook) confirm the existence and title of the study and its focus on nestling sex ratios.
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wikipedia NEUTRAL — Birds are a group of warm-blooded vertebrate animals constituting the class Aves, characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chamb…
https://en.wikipedia.org/wiki/Bird
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wikipedia NEUTRAL — The great horned owl (Bubo virginianus), also known as the tiger owl (originally derived from early naturalists' description as the "winged tiger" or "tiger of the air") or the hoot owl, is a large ow…
https://en.wikipedia.org/wiki/Great_horned_owl
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wikipedia NEUTRAL — The bald eagle (Haliaeetus leucocephalus) is a bird of prey found in North America. A sea eagle, it has two known subspecies and forms a species pair with the white-tailed eagle (Haliaeetus albicilla)…
https://en.wikipedia.org/wiki/Bald_eagle
+ 3 more evidence sources
help
Claim 8: “Solitary young are more likely to be female than male”
INSUFFICIENT EVIDENCE
No evidence was found in the provided search results regarding solitary young and their likelihood of being female.
info
Claim 9: “The paper's lead author, Cheryl Dykstra, has been studying red-shouldered hawks in Ohio for 30 years.”
SINGLE SOURCE
The specific detail about Cheryl Dykstra studying hawks in Ohio for 30 years is mentioned in the EurekAlert! and related press releases, but not independently verified by other distinct biographical or academic sources in the provided evidence.
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wikipedia NEUTRAL — The barred owl (Strix varia), also known as the northern barred owl, striped owl or, more informally, hoot owl or eight-hooter owl, is a North American large species of owl. A member of the true owl f…
https://en.wikipedia.org/wiki/Barred_owl
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wikipedia NEUTRAL — This is a list of notable American non-officeholders who endorsed Donald Trump for the 2024 U.S. presidential election.
https://en.wikipedia.org/wiki/List_of_Donald_Trump_2024_pres…
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wikipedia NEUTRAL — The United States was the host nation of the 1984 Summer Olympics in Los Angeles, California. It was the nineteenth time that Team USA participated, having boycotted the 1980 Summer Olympics four year…
https://en.wikipedia.org/wiki/United_States_at_the_1984_Summ…
+ 3 more evidence sources
verified
Claim 10: “red-shouldered hawks can adjust the sex ratios of their offspring prior to hatching”
VERIFIED
The Journal of Raptor Research evidence explicitly states that the probability of producing female young increased with territory quality, implying an adjustment of sex ratios prior to hatching.
travel_explore
web search NEUTRAL — Mar 12, 2026 ... The probability of parents producing female young increased with increasing territory quality (z = 2.91, P = 0.003), and the proportion of male ...
https://bioone.org/journals/journal-of-raptor-research/volum…
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web search NEUTRAL — Mar 19, 2026 ... As a general rule female raptors (for sure in buteos) are about 1/3 larger than males, but there regional variations in sizes also so it's ...
https://www.facebook.com/groups/BirdingNevada/posts/26505901…
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web search NEUTRAL — empirical evidence that animals with chromosomal sex determination systems are actually capable of adjusting their offspring sex ratios in an adaptive way (for.
https://royalsocietypublishing.org/rspb/article-pdf/263/1368…
info Disclaimer: This analysis is generated by AI and should be used as a starting point for critical thinking, not as definitive truth. Claims are verified against publicly available sources. Always consult the original article and additional sources for complete context.