When children draw pictures of nature, they almost always reach for birds and mammals — a dog, a rabbit, a songbird. Spiders, beetles, and worms rarely make the page. A sweeping new survey of 868 animal behavior researchers, published in Ecology and Evolution, confirms that professional biologists operate on the same emotional logic: the animals they choose to spend their careers studying are governed less by scientific convenience than by personal fondness. The sharpest evidence is the mollusk. Snails, clams, and their relatives ranked among the easiest animals to find, observe, raise, and buy — yet fewer than 6% of the researchers surveyed had ever studied one.

That paradox — the easiest organisms to work with also being the most ignored — is what makes this study more than a complaint about academic fashion. It is a controlled test of the claim that research bias in ecology and evolution exists because some animals are simply more tractable. The results of the survey, led by Pietro Pollo and Michael Kasumovic of the University of New South Wales in Sydney, Australia, and published in the journal’s October 2026 issue, say that claim does not hold up. What predicts a scientist’s choice of study organism is not how easy it is to work with. It is how much they like it.

Survey Design: What 868 Researchers Were Actually Asked

Pollo and Kasumovic recruited 868 animal behavior researchers voluntarily and asked them to rate nine broad animal groups on multiple dimensions: ease of finding, observing, rearing, and purchasing; economic and social usefulness; and — the critical variable — how much they simply liked each group. They also asked which groups participants had actually worked with, and when and how they came to study their most recent organism.

Birds and mammals dominated the researchers’ actual study choices: roughly 43% had worked with birds, and approximately the same proportion with mammals. Insects followed at around 35%, fish at 24%. Mollusks sat at the bottom, studied by only about 6% of participants.

“Finding Nemo may have inspired many people to become marine biologists,” said Pollo, the study’s lead author. “In nature documentaries the focus is usually on polar bears, lions, elephants and other mammals, and that is where most research interest and funding ends up.”

Convenience Doesn’t Explain It: The Mollusk Paradox in Detail

The survey’s most direct refutation of the convenience hypothesis came from the cross-group analysis. Birds and mammals were rarely rated as easier to work with than other animal groups; in laboratory settings, they were frequently rated as the more difficult option. Mollusks, meanwhile, were consistently rated as easy to obtain, observe, and maintain — both outdoors and in the lab — yet remained almost entirely unstudied by the researchers in the sample.

Practical factors did matter — but only at a finer scale. Within a group such as birds, the species studied by more researchers tended to be rated as easier to work with, suggesting that logistical reasoning helps decide which bird a scientist studies. But it plays almost no role in deciding whether that scientist studies birds rather than beetles. At the between-group level, where the largest and most consequential bias lives, the predictor is emotional.

What did align with research choices was warmth. Researchers felt more positively about the groups they studied, and the groups they studied most were overwhelmingly the vertebrates that tend to generate public affection. Perceived usefulness to people was only weakly predictive and did not resolve the gap: researchers rated insects as roughly as economically important to society as mammals, yet were considerably more likely to have done applied work — pest control, conservation, disease control — with mammals than with insects.

How Scientific Biases Get Passed Down

The survey also traced how these preferences travel through academic generations, and the results point to a mechanism that cannot be corrected by individual awareness alone. Among researchers who first began working with their most recent study animal during or before their PhD, approximately 70% credited a supervisor or collaborator as the source — someone who already worked with that animal or actively suggested it. Researchers who had obtained permanent positions were considerably more likely to have made independent choices: about 60% of those who chose a new study organism after securing such a job said the decision was their own.

The implication is structural. Early-career scientists — the portion of the workforce with the most flexibility to change direction — are largely locked into the choices of senior scientists who came before them. A student drawn to spiders or pill bugs may simply be unable to find a supervisor who works on them, funneling new researchers back into whichever groups already dominate the literature. Because the bias is reproduced through the mentorship hierarchy, not just through individual preference, correcting it requires institutional intervention — in hiring criteria, grant structures, and training programs — rather than simply informing researchers that the bias exists.

Liking an Animal and Studying It Feed Each Other

Pollo and Kasumovic also documented a reinforcing cycle: liking an animal makes a scientist more likely to study it, and studying it tends to increase that liking further. Researchers who worked with spiders and their relatives reported a notably larger rise in affection for their subjects over the course of their work than did those who studied birds or mammals — a finding the authors suggest could be deliberately harnessed to broaden the field, if early exposure to neglected groups were built into training programs. The survey’s full findings on taxonomic affinities are available at the journal’s website.

Hobbies appeared as a quiet driver. Bird researchers were more likely than invertebrate researchers to have engaged with their study organisms recreationally before their scientific careers began — through birdwatching, primarily. Scientists who reported a strong preference for fieldwork felt warmer toward spiders and their relatives, yet were less likely to study them — a gap the authors attribute to a possible misconception that such animals are primarily laboratory subjects, when in reality many can be studied outdoors.

Does Ecology’s Cute-Animal Problem Make Its Theories Wrong?

The survey’s findings close a logical circle opened by a companion paper Pollo and Kasumovic published in the same journal earlier this month. That study — an algorithmic audit of 1,383,803 papers across 612 journals, spanning nearly 150 years — found that vertebrates appear in more than half of all ecology and evolution papers focused on a single animal group, a share that has held essentially constant since the early 2000s, when researchers first began measuring it. Biologists have now described more than 1.5 million animal species. Only 4.7% are vertebrates. Birds and mammals together account for less than 1% of animal species.

The survey’s emotional-driver finding explains the persistence of that imbalance. But it also raises a harder question: if the empirical foundation of ecology and evolutionary biology has been built predominantly on roughly 5% of animal diversity, how much of what the field calls universal laws are actually principles derived from an emotionally convenient sample?

The concern is not hypothetical. Several foundational findings in animal behavior, physiology, and developmental biology came from invertebrate model systems — the fruit fly Drosophila melanogaster, the nematode Caenorhabditis elegans, the sea slug Aplysia californica — precisely because their simplicity revealed mechanisms that vertebrate complexity conceals. Parental milk-feeding, studied primarily in mammals because they are the iconic case, has since been discovered in caecilians (limbless amphibians), at least one cockroach species, and a jumping spider — all groups that would rarely have been examined without specific research programs. These examples appear throughout the survey’s analysis of missed discoveries.

“We don’t know what we don’t know,” Pollo said. “The next major discovery could be in an organism we currently ignore because we don’t find it cute or exciting.”

What “Model Organism” Gets Wrong in Ecology

Pollo and Kasumovic challenge what they describe as the arbitrary status of “model organisms” in ecology and evolution — a label that the survey found researchers applied inconsistently and well beyond its original meaning. Barn swallows and crab-eating macaques were among the examples: named by respondents as “model organisms” in ecology, though neither appears on the formal lists maintained by bodies such as the US National Institutes of Health for that designation.

In molecular biology, the model organism designation exists for defensible scientific reasons — the short generation time of Drosophila, the transparency of C. elegans, the tractable genetics of yeast make them genuinely optimal for specific mechanistic questions. In ecology and evolution, where the questions frequently require comparative breadth across animal life, using the label to entrench vertebrate choices does not serve scientific productivity. It serves institutional inertia. The authors argue the label should largely be retired from ecology and evolutionary biology.

What Is at Stake: Conservation Funding Follows Research Attention

The research bias has material consequences that reach well beyond the journal literature. A 2025 study led by Prof. Benoit Guénard and colleagues at the University of Hong Kong, published in the Proceedings of the National Academy of Sciences, analyzed 14,566 conservation projects spanning 25 years and found that of the $1.963 billion allocated worldwide, 82.9% went to vertebrates — while invertebrates and plants each received about 6.6%. Nearly 94% of species identified as threatened and at direct risk of extinction received no conservation project funding at all.

Invertebrates are also dramatically underrepresented on the IUCN Red List — the global benchmark whose status underpins most major conservation funding decisions. Of the estimated one million described insect species, only about 1.2% — roughly 12,000 species — have received a Red List assessment. Without a Red List assessment, a species has no official threat status and is effectively excluded from the primary mechanisms for attracting protection funding — a compounding disadvantage that begins, as Pollo and Kasumovic’s survey now shows, with a researcher choosing not to study the organism in the first place.

The stakes are not abstract. Insects and other invertebrates underpin ecosystem services on which human food production depends. Invertebrate populations are declining at rates that independent monitoring is only beginning to measure. Research on flying insect biomass in German nature reserves, published by Hallmann and colleagues in PLOS One, found a 76% decline over 27 years. Among pollinators specifically — primarily insects — the UN science panel on biodiversity (IPBES) estimates the annual market value of pollinator-dependent crops at $235 billion to $577 billion globally. Scientists cannot respond effectively to declines they cannot measure well. And they cannot measure well what the field has spent generations undercounting.

“We have millions of species and limited time and funding, so we need to diversify our research as much as we can,” Pollo said.

What Would Actually Change This Pattern

Pollo and Kasumovic stop short of placing blame on individual scientists. The survey data shows that researchers feel positively about all nine animal groups they assessed. The issue is one of degree, and of systems that amplify small initial differences in preference into large structural imbalances.

Their prescriptions target those systems directly. They call for science education that introduces a wider range of animal life starting in early childhood — an intervention the survey data supports, given how strongly pre-career hobbies predicted eventual research focus. They propose that universities and funding agencies give explicit preference to neglected taxonomic groups in hiring decisions and grant allocation. They point to citizen science platforms such as iNaturalist’s wildlife sighting database, which aggregates wildlife sightings near research institutions and could help scientists identify tractable invertebrate study systems in their own backyards.

The key word in their proposals is structural. A researcher informed of the bias is not thereby freed from it, because the bias is not primarily an information problem. It is reproduced through the mentor-to-trainee pipeline — the same pipeline that explains why 70% of early-career researchers in the survey adopted their study animals from supervisors rather than their own investigation. No amount of awareness will change a graduate student’s options if the available supervisors all study birds. Changing the options requires changing who gets hired, what gets funded, and what gets rewarded — decisions made at the institutional level, not the individual one.

Whether those institutional changes will materialize is the open question. The scientific community has recognized and documented the taxonomic bias in ecology and evolutionary biology for more than two decades. Michael R. Donaldson’s widely cited 2016 analysis in the journal FACETS found that while each mammal species listed on the IUCN Red List had been the subject of an average of 17 research papers, the typical invertebrate species had attracted one paper or fewer — and concluded that the bias was “not for a lack of availability, but for a lack of interest.” Malcolm Rosenthal and Maydianne Andrade identified the same pattern inside the journal Animal Behaviour in 2017, documenting that vertebrate papers drew more citations than arthropod papers even after controlling for other variables. Those analyses named the problem. Pollo and Kasumovic’s new survey names the mechanism that keeps it running.

Frequently Asked Questions

Why do most scientists study birds and mammals instead of insects or spiders?

The new survey of 868 animal behavior researchers found that emotional preference — how much a researcher likes a given animal group — is the strongest predictor of which groups get studied across the board. Birds and mammals tend to generate warmer feelings, partly because of cultural exposure through media, wildlife documentaries, and childhood experiences. This happens even when the practical case for studying another group is stronger: mollusks ranked among the easiest animals to work with in the survey but were studied by fewer than 6% of participants.

Does the research gap actually put the most important animals at risk?

Yes — in a measurable way. Conservation funding follows research attention: a 2025 study led by researchers at the University of Hong Kong found that of the $1.963 billion conservation funding tracked over 25 years, 82.9% went to vertebrates, while insects and other invertebrates received about 6.6%. Invertebrates also comprise only about 1.2% of the IUCN Red List for insects — the assessment that determines eligibility for most conservation resources. Since insects underpin pollination, soil formation, and decomposition, their decline carries direct risks for agriculture and ecosystem stability. The IPBES pollinator economic assessment estimates annual crop value dependent on pollinators at $235 billion to $577 billion globally.

Can individual scientists decide to study ignored animals and fix this?

Only partially. The survey found that about 70% of early-career researchers adopted their study organisms from a supervisor or collaborator, not from their own deliberate choice. The implication is that the bias is structurally reproduced through the academic mentorship pipeline. A graduate student drawn to neglected animals cannot study them if no available supervisor works on them. Correcting the bias requires institutional action — reforming hiring criteria, grant priorities, and curricula — not only individual awareness.

Are there scientific discoveries scientists might be missing because of this bias?

Yes, and researchers have documented specific cases. Parental milk-feeding behavior — first studied in mammals as the defining case — was subsequently found in caecilians, a jumping spider, and at least one cockroach species, all groups rarely examined. The survey’s discussion of missed discoveries notes that invertebrate model systems such as Drosophila and C. elegans generated some of biology’s most important mechanistic insights precisely because testing assumptions derived from vertebrate study against invertebrate biology revealed where those assumptions broke down. A field that systematically produces fewer studies on invertebrates is running a less diverse and smaller test of its own hypotheses.

The primary study, “Drivers of Taxonomic Bias in Ecology and Evolution: Insights From Ethologists and Behavioural Ecologists,” was published in Ecology and Evolution (DOI: 10.1002/ece3.74460). The companion paper, “Taxonomic Bias: A Persistent Issue in Ecology and Evolution,” was published October 4, 2026, in the same journal (DOI: 10.1002/ece3.74450).