Latest news with #ÇağlarAkçay
Yahoo
3 days ago
- Science
- Yahoo
The surprisingly relatable reason why some birds get cranky
Trafficked roads, loud noises, suffocating smog. For some people, living in the city can be stressful and unnerving. But a growing body of research shows some city birds can be more aggressive than their rural counterparts, suggesting they too feel the pressures of city life. In a study published in April in the journal Animal Behavior, researchers showed that Galápagos yellow warblers that live near trafficked roads in the Ecuadorian archipelago respond to intruders more aggressively than those living farther away from traffic. They're not the only bird species affected by city life. Numerous studies have investigated the phenomenon of angry urban birds—finding that species such as great tits, European robins, song sparrows, and dark-eyed juncos show more aggression toward each other when they live near urbanized sites. While it's clear that 'in some species of birds, urban populations are more aggressive than rural populations,' there are many different theories for why this happens, says Jeremy Hyman, a professor and department chair of biology at Western Carolina University. In the last decades, the Galápagos archipelago has seen a drastic increase in the human population, with permanent residents today increasing by six percent each year. An increase that requires more infrastructure to house more people, and more cars to move them around. This makes it a perfect 'laboratory' to study how birds respond to new, busy conditions, according to study authors. The researchers selected 38 warbler territories on two islands of the archipelago: Santa Cruz Island, and Floreana Island; both crossed by a main road used by cars. The warblers were located either near the road or at least 300 feet away. In each territory, they played recordings of traffic noise and warblers singing, which simulated an intrusion. 'Each bird was tested once with just the warbler speaker being active, and once with the warbler speaker plus the [car] noise speaker active,' says Çağlar Akçay, a behavioral ecologist at Anglia Ruskin University in Cambridge and study author. When exposed to the sounds of encroaching birds and car noise playing in the background, the warblers living close to the road responded more aggressively than when there was no noise playing. They also responded more aggressively to noise compared to their 'rural' counterparts—getting closer to the speakers and sometimes even attacking them. Mike Webster, an ornithologist at the Cornell Lab of Ornithology who was not involved in the research, says the study is 'pretty convincing' and offers a clear look at how a single environmental change can influence behavior. '[It] really kind of helps us focus in on what the causes of the differences in behavior might be,' he says. Generally, animals that live in cities tend to be bolder and more aggressive—both characteristics that enable them to survive in such complex habitat. 'Individuals that can't deal with constant disturbance, such as noise, people, cars, etc. would be unlikely to thrive in an urban habitat,' says Hyman. Some birds may become more aggressive because cities are rich in food sources—and so there's strong competition to establish a foothold. 'Only the most aggressive males can manage to hold a territory in this place where lots and lots of birds would like to have a territory,' says Hyman. But food scarcity may also make some urban species more aggressive, and so 'birds have to fight an awful lot in order to maintain a large enough territory to get the resources that they need.' High levels of stress caused by noise and other factors might also play a role in making birds more aggressive, notes Hyman. But does being more aggressive enhance your chances of survival? In some cases, aggression seems to be 'a worthwhile cost', says Sarah Foltz, a behavioral ecologist at Radford University. One study that looked at song sparrows living in southwest Virginia showed that aggression didn't impact how much bird parents invested in their offspring. Female birds even spent as much and sometimes more time at the nest than their less aggressive rural counterparts. Overall, the benefits of being more aggressive seem to depend on the kind of habitat the birds are in. For some species, like the song sparrow, some urban areas offer suitable habitats with more food and fewer predators. They might become more aggressive to defend it, and ensure a good habitat were to raise their offspring—and so have better chance of survival. Another 'big unanswered question,' says Hyman, is whether birds learn to be aggressive during their lifetime, or if birds born in urban populations have some measure of aggression encoded in their genes. 'There's little bits of evidence on both sides,' he says. But what scientists do know is that some birds can be highly adaptable. 'Aggression definitely has a genetic component to it,' says Foltz. 'But also, we know that when we change environmental factors, birds change their aggression' Overall, Foltz says scientists are still trying to understand just how much urban density different species can tolerate and which characteristics of an urban environment influence aggressiveness the most. 'We've got all these little pieces,' she says, 'But it's still coming together to make a bigger picture, so it's sort of an unfinished puzzle.'
Forbes
12-04-2025
- Science
- Forbes
Traffic Noise Provokes ‘Road Rage' In Male Galápagos Warblers
Yellow warblers near busy roads become increasingly aggressive when traffic drowns out their territorial songs, and noise pollution could trigger fights. A pair of Galapagos Yellow Warblers (Setophaga petechia aureola; Female, left; male, right). (NOTE: ... More This image has been cropped from the original. Credit: Çağlar Akçay / Anglia Ruskin University) A recent study has found that songbirds in the Galapagos Islands are changing their behavior because of human noise. Basically, birds exposed to vehicles moving along a roadway were found to show increased territorial aggression and to sing louder songs. 'Birds use song during territorial defense as an aggressive signal,' explained the study's co-author Çağlar Akçay, a Senior Lecturer in the School of Life Sciences at Anglia Ruskin University, where he studies animal behavior and communication. 'However, if external noise, such as traffic, interferes with the signaling, effectively blocking this communication channel, increasing physical aggression would be an appropriate response,' Dr Akçay added. Increased physical aggression has consequences. A 2020 study found that the mortality rate of wild songbirds along roads in the Galápagos Islands was much higher than in other natural areas (ref). This earlier study provided the researchers with the motivation to form an international collaboration to ask how this growing threat could be minimized. Topographic and bathymetric map of the Galápagos Islands, Ecuador. (Credit: Eric Gaba, translated by ... More NordNordWest / CC BY-SA 3.0) The Galápagos Islands or Islas Galápagos in Spanish, are a remote archipelago of consisting of 16 volcanic islands in the eastern Pacific Ocean located roughly 900 km (560 miles) off the coast of Ecuador and clustered around the equator. They were visited by Charles Darwin in September 1835 when he was just 22 years old. These islands are home to many species of birds and animals that are found nowhere else in the world, and are well-known for their giant tortoises, which comprise 15 subspecies (13 extant and 2 extinct). Tragically, these giant tortoises were almost all wiped out by humans (who ate them) along with their pests, particularly black and brown rats and domesticated goats (which competed for scarce food and destroyed the fragile habitat). Today, these islands are widely viewed as a natural living laboratory by scientists, particularly evolutionary biologists, ever since its finches inspired Darwin's theory of evolution by means of natural selection. However, despite their scientific importance, recent decades have seen significant human population growth. Along with a rise in tourism, the permanent human population is increasing by over 6% per year, leading to more and more vehicle traffic on the islands' roads. This increased vehicle traffic is leading to large increases in birds are killed by automobiles. Amongst those fatalities, Galapagos yellow warblers are far-and-away the most common victims. 'An earlier study by Garcia-Carrasco et al (2020) found that 70% of the roadkill on the main road in Santa Cruz are yellow warblers (ref),' Dr Akçay pointed out in email. Adult male Galapagos Yellow Warbler (Setophaga petechia aureola), singing. (Credit: Alper ... More Yelimlieş.) Galapagos yellow warblers will look familiar to most birders: they are a subspecies of the migratory yellow warbler, Setophaga petechia, which is the most widespread species of Setophaga warblers in the New World. They breed throughout almost all of North America and the Caribbean, and even in the northern parts of South America – including the Galapagos, where they are resident. In the Galapagos, the yellow warbler, Setophaga petechia aureola, differs somewhat in appearance from its mainland cousins by having a rust-colored cap on its head. Its genetic divergence is low, probably because it colonized the archipelago relatively recently; less than 300,000 yrs ago. These warblers are insectivorous, and thus, they likely also face human pressures from growing pesticide use. The study was co-led by both Leon Hohl and Alper Yelimlies, who were volunteers in the lab of senior author, organismal systems biologist Sonia Kleindorfer, at the University of Vienna. Professor Kleindorfer is an expert on how animal behavior shapes evolutionary dynamics in birds and parasites. (Mr Yelimlieş is now a graduate student in Professor Kleindorfer's lab.) A yellow warbler catching flies from atop a Galápagos tortoise whilst it was munching grass. ... More (Credit: Matthew Roth / CC BY-NC 2.0) In this study, Dr Akçay and collaborators asked whether Galápagos yellow warblers show increased aggression and flexibility in their song when confronted with a simulated intruder under conditions of experimentally increased traffic noise depending on their experience with such noise. To do this, the researchers studied the behaviors of 38 males on two islands within the Galápagos Archipelago, Floreana and Santa Cruz. Whilst 20 of the study birds lived within 50 meters of the nearest road, 18 others nested more than 100 meters away from traffic. Dr Akçay and collaborators placed a speaker in the territory of each study male, and played two different recorded soundtracks on different days. One soundtrack featured the song of another male Galápagos yellow warbler, whilst the other featured traffic sounds in addition to warbler songs. The males that lived near busy roadways behaved more aggressively than those living farther away by approaching the speaker closely and repeatedly swooping low over it, probably in search of the intruder. By contrast, males that lived farther away from roads were less aggressive when traffic noises were present in addition to warbler songs. Were these birds afraid of the unfamiliar traffic noises? Dr Akçay and collaborators also reported that males living on the more densely populated Santa Cruz Island sang for longer periods of time when traffic sounds were present, whilst the reverse was true for those warblers on the more sparsely populated Floreana Island. And yet, the effect of living on a roadside territory was noticeable even on tiny Floreana Island, which has a total population of roughly 10 vehicles, suggesting even minimal traffic affects the birds' responses to noise. 'Our results show that the change in aggressive responses in yellow warblers occurred mainly near roads,' Dr Akçay reported. 'Birds occupying roadside territories on both islands, and therefore having regular experience of traffic noise, may have learned to increase physical aggression when the territorial intrusion was accompanied by traffic noise.' In addition to escalating their physical aggression, Galápagos yellow warblers living on the more populous island of Santa Cruz increased the duration of their song when confronted by traffic noise. 'We also found some evidence of birds trying to cope with noise by adjusting their song, with yellow warblers in all habitats increasing the minimum frequency of their songs to help them be heard above the traffic noise,' Dr Akçay reported. These findings indicate that an individual bird's previous experience with traffic noise motivates them to adapt and adjust relevant features of their songs. How did the female warblers react to traffic noises? 'Unfortunately, the responses of females to anthropogenic noise have been understudied,' Dr Akçay replied in email. 'During breeding, females are quite unresponsive to territory intrusions, yet during non-breeding they are as aggressive as male warblers,' Dr Akçay pointed out in email. 'These make the same questions (whether aggression or songs are affected by noise) relevant for females as well. We are currently working on several studies on female song and duetting in this species including a follow-up study to this one investigating the influence of noise on female warblers and pair defense behavior.' What are the most important lessons to be learned from this study? 'Our study shows the importance of considering behavioral plasticity in conservation efforts and developing strategies to mitigate the effects of noise pollution on wildlife,' Dr Akçay explained. 'It also highlights the significant impact of human activities on wildlife behavior, even in relatively remote locations such as the Galápagos Islands.' Leon Hohl, Alper Yelimlieş, Çağlar Akçay, and Sonia Kleindorfer (2025). Galápagos yellow warblers differ in behavioural plasticity in response to traffic noise depending on proximity to road, Animal Behaviour | doi:10.1016/
The Guardian
20-03-2025
- Science
- The Guardian
Traffic noise triggers road rage among male Galápagos birds
If the rumble of trucks, honk of car horns and bustle of the roads leaves you irritable, you are not alone – researchers say the sound of traffic can leave birds in a rage, too. Researchers have found male Galápagos yellow warblers that live near busy roads on the islands behave more aggressively when they hear songs from another male if they occur in the presence of traffic sounds. The researchers say the findings might be down to the birds realising that their own songs, which act as a warning towards intruders to their territory, could be masked by the sound of the traffic. 'Communication usually is in lieu of physical aggression but, if the communication is not possible because of noise, then they might actually engage in risky behaviours that would lead to a physical fight,' said Dr Çağlar Akçay, a co-author of the research from Anglia Ruskin University. Writing in the journal Animal Behaviour, the team reported how they studied the behaviour of 38 males on two islands in the Galápagos. While 20 of the birds lived near roads, 18 nested away from traffic. Within the territory of each male, the team played two recorded soundtracks on different days. One soundtrack only featured the song of another male Galápagos yellow warbler, while the other additionally featured traffic sounds. The team found males that lived near busy roads behaved more aggressively in the latter case, approaching and flying around the speaker in search of the intruder. Akçay said that while one possibility was that they got closer to make themselves heard, not all males sang as they approached – suggesting they were ready for a dust-up. 'If there was an actual bird instead of a speaker, that would mean … a challenge, essentially, and that could result in a physical fight,' he said. By contrast, males that lived away from roads showed less aggression when traffic noises were present – possibly, the team suggests, because they were scared by the unfamiliar sound. The scientists said males living on the more densely populated Santa Cruz Island sang for longer when traffic sounds were present, while the reverse was true for those on the more sparsely populated Floreana Island. Sign up to Down to Earth The planet's most important stories. Get all the week's environment news - the good, the bad and the essential after newsletter promotion However, across the board, males slightly increased the minimum frequencies of their songs when traffic sounds were played – possibly to make it easier for others to hear them. And, while an increase in peak frequency was only seen in males that lived away from traffic, the team suggests that could be because the birds that lived near roads were already singing at the optimum peak frequency. Akçay said it was possible birds that were better able to deal with traffic noise settled near roads but, alternatively, it could be that birds adapt as a result of living near traffic. And, because there are very few people on Floreana, that raises another point. 'Even that little experience [of traffic], apparently, has some effect,' he said. 'We have to think about noise pollution even in places like Galápagos, I think, and the impact of noise pollution on the unique species there.'
