Gram Research analysis shows that Azores woodpigeons are eating far more exotic and cultivated plants than native species, with 159 plant taxa detected across 450 samples. Despite native plants remaining available, pigeons in damaged habitats strongly prefer exotic foods, shifting their diet based on what’s easiest to find. This flexibility helps the birds survive environmental changes, but it may prevent native forests from regenerating because the pigeons stop dispersing native seeds.
Scientists studying pigeons on the Azores islands discovered something surprising: these birds are eating way more exotic and cultivated plants than native ones, even though native plants are disappearing. Using DNA analysis on pigeon droppings, researchers found that 159 different plant species make up the birds’ diet. The pigeons are incredibly adaptable—they eat whatever food is available, which helps them survive in damaged habitats. However, this shift toward exotic plants might actually harm the islands’ natural ecosystems by reducing the spread of native seeds that forests need to regrow.
Key Statistics
A 2026 research article analyzing 450 pigeon droppings found that Azores woodpigeons consumed 159 different plant species, with exotic and cultivated plants dominating their diet despite the availability of native plants.
According to research reviewed by Gram, pigeons in simplified, damaged island landscapes showed more generalist feeding behavior and ate significantly more exotic plants compared to pigeons in less disturbed habitats.
The study revealed marked seasonal variations in pigeon diet composition, with fruit availability driving major shifts in what the birds ate throughout the year across the Azores archipelago.
The Quick Take
- What they studied: How Azores woodpigeons change their eating habits when their natural island homes are damaged or transformed by human activity
- Who participated: 450 pigeon droppings collected from two islands in the Azores archipelago, analyzed to determine what plants the birds were eating
- Key finding: Pigeons ate 159 different plant species, with a strong preference for exotic and cultivated plants over native species, especially in areas where natural habitats were most damaged
- What it means for you: While these pigeons are surviving well by being flexible eaters, their shift away from native plants could slow down forest recovery on these islands. If you care about island conservation, this shows how human habitat changes create unexpected ripple effects through entire ecosystems.
The Research Details
Researchers collected droppings from Azores woodpigeons on two different islands and used advanced DNA technology called metabarcoding to identify exactly which plants the birds had eaten. This method is like reading a receipt that shows everything a bird ate—the DNA in the droppings reveals plant species even after they’ve been digested. The team collected 450 samples total and analyzed them to see what plants appeared in different seasons and in different types of habitats (from heavily damaged areas to less disturbed zones).
The researchers compared what pigeons ate in different seasons to understand how food availability changes throughout the year. They also looked at whether pigeons in simplified, damaged landscapes ate differently than pigeons in areas with more natural vegetation. This approach allowed them to see the complete picture of how these birds adapt their diet based on what’s available around them.
Understanding what pigeons eat is crucial because these birds are seed dispersers—they eat fruits and seeds, then spread them across the islands through their droppings. When pigeons shift from eating native plants to exotic ones, they stop helping native forests regenerate and instead help spread invasive species. This research method (DNA analysis of droppings) is important because it reveals the real diet without disturbing the birds, giving scientists accurate information about ecosystem changes.
This study used cutting-edge DNA technology that can identify plant species with high accuracy, even in digested material. The large sample size of 450 droppings provides solid evidence. The researchers studied two different islands, which strengthens their findings by showing patterns across locations. However, the study doesn’t specify exactly how many individual birds were sampled, so we don’t know if the 450 samples came from many birds or just a few. The research was published in a peer-reviewed journal, meaning other scientists reviewed it for quality.
What the Results Show
The Azores woodpigeons showed remarkable flexibility in their diet, consuming 159 different plant species across the 450 samples analyzed. The most striking finding was that despite native plants still being available, the pigeons ate far more exotic and cultivated plants—species that humans introduced to the islands. This pattern was especially strong in areas where natural habitats had been heavily damaged or simplified by human activity.
Seasonal changes were dramatic: the pigeons’ diet shifted significantly depending on the time of year, primarily because fruit availability changed with the seasons. In seasons when native fruits were scarce, pigeons relied even more heavily on cultivated and exotic plants. This shows the birds are opportunistic feeders—they eat whatever is easiest to find and most abundant at any given time.
Geographic differences were also important: pigeons living in simplified, damaged landscapes were more generalist eaters (eating a wider variety of foods) compared to pigeons in less disturbed areas. Interestingly, this generalist approach in damaged habitats meant the birds ate more exotic plants and fewer native plants. The researchers suggest this happens because damaged areas have fewer native plants available, forcing pigeons to rely on whatever exotic species have colonized those spaces.
The research revealed that native plants remained a significant part of the pigeons’ diet despite habitat loss, suggesting these birds still prefer native species when available. However, the dominance of exotic plants in the diet indicates that natural resources are severely limited on these islands. The study also showed that the pigeons’ trophic plasticity—their ability to eat many different foods—is what allows them to survive in these changing environments. Without this flexibility, the pigeon population might have declined dramatically.
This study adds important detail to what scientists already knew: island birds are often very adaptable eaters. Previous research showed that pigeons and doves are important seed dispersers on islands worldwide. This research confirms that pattern while revealing a concerning trend: as habitats degrade, these birds shift from dispersing native seeds to dispersing invasive species seeds. This creates a feedback loop where habitat damage leads to more invasive species, which further damages native habitats.
The study doesn’t tell us exactly how many individual pigeons were sampled—just that 450 droppings were collected. This matters because if most samples came from a few birds, the results might not represent the whole population. The research only looked at two islands in the Azores, so we don’t know if these patterns apply to all islands in the archipelago or to other pigeon populations worldwide. The study also doesn’t measure how much seed dispersal actually happens or whether the shift to exotic plants is significantly harming native forest regeneration—those would require additional research.
The Bottom Line
If you’re involved in island conservation efforts, this research suggests that protecting remaining native plant communities is critical—not just for the plants themselves, but because they provide food sources that keep pigeons eating native seeds. Reducing habitat damage and removing invasive plant species could help restore the balance of what pigeons eat. These recommendations have moderate confidence because the study clearly shows the pattern but doesn’t test whether these interventions would actually work. For policymakers, the finding suggests that habitat restoration should be a priority to maintain healthy ecosystem functions.
Island conservation managers and environmental policymakers should care most about these findings, as they directly affect ecosystem restoration efforts. Ecologists studying how animals adapt to climate change and habitat loss will find this research valuable. Birdwatchers and nature enthusiasts on the Azores might be interested in understanding how their local pigeons are changing. However, people living on mainland continents with stable ecosystems won’t see direct impacts from this research, though it illustrates broader principles about how ecosystems respond to human changes.
Changes in pigeon diet happen relatively quickly—within seasons as food availability shifts. However, the full ecosystem consequences of this dietary shift (whether native forests actually fail to regenerate) would take years or decades to become obvious. If habitat restoration efforts were implemented, it might take 5-10 years to see measurable changes in pigeon foraging behavior and seed dispersal patterns.
Frequently Asked Questions
Why are island pigeons eating more exotic plants instead of native plants?
Habitat damage has reduced native plant availability, forcing pigeons to eat whatever is abundant. Exotic plants often thrive in disturbed areas, making them easier to find. Pigeons are opportunistic feeders that eat the most available food source, regardless of whether it’s native or introduced.
How do scientists know what pigeons eat without watching them all day?
Researchers use DNA metabarcoding on pigeon droppings to identify plant species in the birds’ diet. This advanced technique reads the DNA of plants in the droppings, revealing exactly what was eaten. The method analyzed 450 samples and identified 159 plant species.
Does it matter if pigeons eat exotic plants instead of native ones?
Yes, significantly. Pigeons disperse seeds through their droppings. When they eat exotic plants, they spread invasive species instead of helping native forests regenerate. This creates a harmful cycle where invasive plants increase, native habitats decline further, and ecosystem health deteriorates.
Can pigeons survive if all native plants disappear from islands?
Pigeons can survive on exotic plants alone because they’re highly adaptable eaters. However, this doesn’t mean ecosystems stay healthy. The loss of native seed dispersal threatens entire forest ecosystems that depend on pigeons to spread native seeds and maintain biodiversity.
What can be done to help native plants on damaged islands?
Protecting remaining native plant communities and removing invasive species could restore food sources that encourage pigeons to eat native seeds again. Habitat restoration efforts take years but can gradually shift pigeon foraging behavior back toward native plants and restore ecosystem balance.
Want to Apply This Research?
- Users interested in island conservation could track native plant species sightings in their local area and note whether they see pigeons feeding on them. Specifically: count native fruit-bearing plants visible in a defined area monthly and record pigeon activity near those plants.
- If using a conservation or nature-tracking app, users could contribute observations of what plants pigeons are eating in their region by photographing birds with food or noting plant species in areas with high pigeon activity. This crowdsourced data helps scientists understand local patterns.
- Over 6-12 months, track the ratio of native to exotic plants in areas you regularly visit, and note pigeon presence. This long-term observation helps identify whether habitat restoration efforts are working or whether invasive species are increasing in your area.
This research describes ecological patterns in a specific pigeon population on the Azores islands and should not be interpreted as applying universally to all pigeon populations or islands. The study identifies correlations between habitat damage and dietary shifts but does not definitively prove causation or quantify the actual impact on native forest regeneration. Readers should consult with local conservation experts and peer-reviewed literature before making management decisions based on this research. This summary is for educational purposes and does not constitute professional ecological or conservation advice.
This research translation is published by Gram Research, the science division of Gram, an AI-powered nutrition tracking app.