The cognitive ecology of individual recognition has been studied in many species, especially in primates or other mammalian species that exhibit complex social behaviours, but comparatively little research has been done on colonial birds. [1] Colonial birds live in dense colonies in which many individuals interact with each other daily. For colonial birds, being able to identify and recognize individuals can be a crucial skill. [2]
Individual recognition is one of the most basic forms of social cognition. [1] If we were to define individual recognition, it would imply that a given individual has the capacity to discriminate a familiar individual from another one at any given time. [2] It is believed that in many species, group size is often a representation of social complexity, with higher social complexity demanding higher cognitive capabilities. [1] This hypothesis is also known as the " social brain hypothesis " [1] and has been supported by many researchers. [3] The logic behind this hypothesis is based on the principle that larger group size will require a higher degree of complexity in their interactions. [3] Many studies have looked at the effect of sociality on the brain development, mostly focussing on non-human primate species. In primates, it has been shown that relative brain size, when controlling for the size of the species and the phylogeny, seemed to correlate with the size of the social group. [1] These results allowed for a direct correlation between sociality and cognition. However, when reproducing such experiments in non-primate species, like with reptiles, birds and even other mammalian species, the correlation between brain size and social group size does not seems to exist. A study done on mountain chickadees looking at the impact of sociality on the hippocampus size as well as on neurogenesis found no evidence of change related to group size, therefore rejecting the "social brain hypothesis" in birds. [4] Further research looking at bird cognitive ecology demonstrated that social complexity is a more reliable proxy for brain size, as it relies not only on the number of individuals but also on the degree of social interactions and more. [1]
In the wild, recognition can have many advantages. When looking at monogamous birds species, being able to recognize your mate can be crucial. [2] As colonial birds tend to cluster in high density groups, finding your mate can be a challenge. Being able to identify your mate is not all, recognition can also help in the context of mate selection as individual recognition allows birds to avoid inbreeding with conspecifics. [5] Inbreeding avoidance has been shown in a species of storm petrel, a colonial seabird that nests in burrows. In the case of storm petrels, individual relatedness is assessed based on olfactory signatures that allow them to distinguish closely related individuals from non-related ones. The capacity of an individual to identify conspecifics is not only used to avoid inbreeding, but can also be used in order to help closely related individuals. Such instances can be seen in scrub jays, whose offspring stay after fledging in order to help raise the next brood. [5]
Moreover, recognition can be useful for chick identification. Being able to recognize your own chick is essential in many colonial bird species as chicks can wander around and mix up with others' chicks. [6] Feeding the wrong chick would result in high cost for the parent with little to no benefit for their own reproductive success. In herring gulls, chicks can be found wandering around the colony only a few days after hatching from the egg, creating a need for the parent to recognize its own chick. However, in order to have evolved, recognition needs to be beneficial not only for one side, but for both sides, meaning that the chick has to be able to recognize its parents as well. Still looking at herring gulls, chicks will often hide when the parents are not present in order to avoid being predated on by other adult herring gulls or any other predator. [7] Therefore, being able to recognize your parent is crucial in order to reveal your position to the right adult. [7] In the case of bird species that raise many offspring at once, chicks that are able to recognize their parents may also increase their begging rate and therefore obtain more food in return. [8] Chicks that have better recognition capacities would therefore have the advantage over their siblings. [8]
It has been believed for a long time that birds had a very bad sense of smell, but recent studies have demonstrated that some species of birds such as the procellariiformes have a quite developed sense of smell. [9] [10] Olfaction seems to be used in an array of different task such as for finding food, migrating and kin recognition. [9] [10] In burrowing species such as in puffins, auks and petrels, smells seem to be at the basis of mate and nest recognition. [11] [12] The procellariiformes, also known as tubed-noses, are one of the best studied groups when it comes to olfaction as they seem to have a quite developed sense of smell. [12] A study done on storm petrels showed that not only do petrels use olfaction in order to find their burrow and their mate, but that they are also aware of their own smell. [11] Petrels nest in dense colonies and use the smell of their mate or their own smell in order to find their burrow and avoid entering the wrong burrow. [11] Such a mechanism of recognition has also been shown in auks as they mostly fly at night, keeping them from using spatial memory in order to find their burrow. When looking at the available literature, olfactory cues seems to be used mostly by colonial birds that nest in burrows. [13]
Concerning chick recognition in burrowing birds, a researcher called Eduardo Minguez (1997) [12] showed that there was no chick recognition in storm petrels. One of the advantages of burrow nesting is that your chick is confined in the burrow until it is ready to fledge, eliminating the need for chick recognition. It is likely that chicks will acquire their "signature smell" only later upon fledging the parental nest. There are few instances of burrowing birds that have the mechanism of chick recognition, [13] but as recognition is a costly mechanism, it tends to be lost in many bird species for which it is not necessary. [14] [15]
In many bird colonies, the environment in the colony tends to be quite loud and filed with countless acoustic stimuli. Many researchers have looked into how individuals can identify each other in such a heavily charged acoustic environment. Recognition based on acoustic signatures has been demonstrated in many bird species such as in penguins, [16] [6] swallows, [13] gulls, [8] razorbills [17] and more. [18] [15] [17] A study done on king penguins by Jouventin et al. (1999) was one of the first study to look at the technicalities behind acoustic recognition. [16] They found that chicks could identify their parents based on an acoustic signature specific to the pattern of the call as well as the frequency of the parents' call. The amplitude of the call did not seem to affect the call signature. A similar study done on black-headed gulls in 2001 obtained similar results supporting that the acoustic signatures of parents' calls is most likely based on a redundant pattern and the frequency of the call with no effect regarding the amplitude. [8] This study also supported that the mechanism of acoustic recognition is most likely the same in most species within the gull family, Laridae. [8] Nevertheless, not all members of Laridae exhibit parent-offspring recognition.
The black-legged kittiwake, a small cliff nesting gull, does not seem to recognize its chick. This lack of recognition is most likely the result of cliff nesting, as chicks cannot explore far from the nest and get mixed with other chicks. Recognition would have then been lost in kittiwakes. [14] Other exceptions can be found, for example in razorbills. [17] Razorbills exhibit parent-offspring recognition, but research has shown that only males and chicks exhibit such behaviour, meaning that females do not recognize their chick and vice versa. [17] Such difference between the parents can be explained when looking at the natural history of razorbills. Like in kittiwakes, razorbills are cliff nesters, limiting the chicks movement quite a bit. [19] [17] However, when the chick will fledge, only the male will bring the chick out at sea and will keep caring for its chicks for a little while after fledging, creating the need to be able to recognize its own chick. [19] [17] As females do not follow its offspring at sea, there is no need for her to recognize her own chick. [17]
Procellariiformes is an order of seabirds that comprises four families: the albatrosses, the petrels and shearwaters, and two families of storm petrels. Formerly called Tubinares and still called tubenoses in English, procellariiforms are often referred to collectively as the petrels, a term that has been applied to all members of the order, or more commonly all the families except the albatrosses. They are almost exclusively pelagic, and have a cosmopolitan distribution across the world's oceans, with the highest diversity being around New Zealand.
The family Procellariidae is a group of seabirds that comprises the fulmarine petrels, the gadfly petrels, the diving petrels, the prions, and the shearwaters. This family is part of the bird order Procellariiformes, which also includes the albatrosses and the storm petrels.
The black-headed gull is a small gull that breeds in much of the Palearctic including Europe and also in coastal eastern Canada. Most of the population is migratory and winters further south, but some birds reside in the milder westernmost areas of Europe. Small numbers also occur in northeastern North America, where it was formerly known as the common black-headed gull. As is the case with many gulls, it was previously placed in the genus Larus.
Behavioral ecology, also spelled behavioural ecology, is the study of the evolutionary basis for animal behavior due to ecological pressures. Behavioral ecology emerged from ethology after Niko Tinbergen outlined four questions to address when studying animal behaviors: What are the proximate causes, ontogeny, survival value, and phylogeny of a behavior?
The Manx shearwater is a medium-sized shearwater in the seabird family Procellariidae. The scientific name of this species records a name shift: Manx shearwaters were called Manks puffins in the 17th century. Puffin is an Anglo-Norman word for the cured carcasses of nestling shearwaters. The Atlantic puffin acquired the name much later, possibly because of its similar nesting habits.
The razorbill, razor-billed auk, or lesser auk is a colonial seabird and the only extant member of the genus Alca of the family Alcidae, the auks. It is the closest living relative of the extinct great auk. Wild populations live in the subarctic waters of the Atlantic Ocean.
The tree swallow is a migratory bird of the family Hirundinidae. Found in the Americas, the tree swallow was first described in 1807 by French ornithologist Louis Vieillot as Hirundo bicolor. It has since been moved to its current genus, Tachycineta, within which its phylogenetic placement is debated. The tree swallow has glossy blue-green upperparts, with the exception of the blackish wings and tail, and white underparts. The bill is black, the eyes dark brown, and the legs and feet pale brown. The female is generally duller than the male, and the first-year female has mostly brown upperparts, with some blue feathers. Juveniles have brown upperparts, and a grey-brown-washed breast. The tree swallow breeds in the US and Canada. It winters along southern US coasts south, along the Gulf Coast, to Panama and the northwestern coast of South America, and in the West Indies.
The European pied flycatcher is a small passerine bird in the Old World flycatcher family. One of the four species of Western Palearctic black-and-white flycatchers, it hybridizes to a limited extent with the collared flycatcher. It breeds in most of Europe and across the Western Palearctic. It is migratory, wintering mainly in tropical Africa. It usually builds its nests in holes on oak trees. This species practices polygyny, usually bigamy, with the male travelling large distances to acquire a second mate. The male will mate with the secondary female and then return to the primary female in order to help with aspects of child rearing, such as feeding.
Wilson's storm petrel, also known as Wilson's petrel, is a small seabird of the austral storm petrel family Oceanitidae. It is one of the most abundant bird species in the world and has a circumpolar distribution mainly in the seas of the southern hemisphere but extending northwards during the summer of the northern hemisphere. The world population was estimated in 2022 as stable at 8 to 20 million birds. In 2010 it had been estimated at 12-30 million. A 1998 book had estimated more than 50 million pairs. The name commemorates the Scottish-American ornithologist Alexander Wilson. The genus name Oceanites refers to the mythical Oceanids, the three thousand daughters of Tethys. The species name is from Latin oceanus, "ocean".
The Australianzebra finch or chestnut-eared finch is the most common estrildid finch of Central Australia. It ranges over most of the continent, avoiding only the cool humid south and some areas of the tropical far north. The bird has been introduced to Puerto Rico and Portugal. Due to the ease of keeping and breeding the Zebra Finch in captivity, it has become Australia’s most widely studied bird; by 2010, it was the most studied captive model passerine species worldwide, by a considerable margin.
The blue-footed booby is a marine bird native to subtropical and tropical regions of the eastern Pacific Ocean. It is one of six species of the genus Sula – known as boobies. It is easily recognizable by its distinctive bright blue feet, which is a sexually selected trait. Males display their feet in an elaborate mating ritual by lifting them up and down while strutting before the female. The female is slightly larger than the male and can measure up to 90 cm (35 in) long with a wingspan up to 1.5 m (5 ft).
The black-legged kittiwake is a seabird species in the gull family Laridae.
The Galápagos petrel is one of the six endemic seabirds of the Galápagos. Its scientific name derives from Ancient Greek: Pterodroma originates from pteron and dromos, meaning "wing" and "runner", and phaeopygia comes from phaios and pugios, meaning "dusky" and "rump". Members of Pterodroma genus are also called the gadfly petrels because their erratic twisting and turning in flight resemble that of gadflies.
The fork-tailed storm petrel is a small seabird of the storm petrel family Hydrobatidae. It is the second-most abundant and widespread storm petrel and is the only bird in its family that is bluish-grey in colour.
Mobbing in animals is an antipredator adaptation in which individuals of prey species mob a predator by cooperatively attacking or harassing it, usually to protect their offspring. A simple definition of mobbing is an assemblage of individuals around a potentially dangerous predator. This is most frequently seen in birds, though it is also known to occur in many other animals such as the meerkat and some bovines. While mobbing has evolved independently in many species, it only tends to be present in those whose young are frequently preyed upon. This behavior may complement cryptic adaptations in the offspring themselves, such as camouflage and hiding. Mobbing calls may be used to summon nearby individuals to cooperate in the attack.
Nesting behavior refers to an instinct or urge in pregnant animals associated with an increase of estradiol (E2) to prepare a home for the upcoming newborn(s). Nest building provides protection against predators and competitors that mean to exploit or kill infants. It also aids in family structure and is therefore influenced by different mating behaviours and social settings. It is found in a variety of animals such as birds, fish, squirrels, mice and pigs, and is said to be done by humans as well. However, recent research into nesting tendencies in women has questioned whether there is really any biological basis for nesting in humans, positing a social explanation instead.
Egg tossing or egg destruction is a behavior observed in some species of birds where one individual removes an egg from the communal nest. This is related to infanticide, where parents kill their own or other's offspring. Egg tossing is observed in avian species, most commonly females, who are involved with cooperative breeding or brood parasitism. Among colonial non-co-nesting birds, egg-tossing is observed to be performed by an individual of the same species, and, in the case of brood parasites, this behavior is done by either the same or different species. The behavior of egg tossing offers its advantages and disadvantages to both the actor and recipient.
The term seabird is used for many families of birds in several orders that spend the majority of their lives at sea. Seabirds make up some, if not all, of the families in the following orders: Procellariiformes, Sphenisciformes, Pelecaniformes, and Charadriiformes. Many seabirds remain at sea for several consecutive years at a time, without ever seeing land. Breeding is the central purpose for seabirds to visit land. The breeding period is usually extremely protracted in many seabirds and may last over a year in some of the larger albatrosses; this is in stark contrast with passerine birds. Seabirds nest in single or mixed-species colonies of varying densities, mainly on offshore islands devoid of terrestrial predators. However, seabirds exhibit many unusual breeding behaviors during all stages of the reproductive cycle that are not extensively reported outside of the primary scientific literature.
Begging in animals is when an animal solicits being given resources by another animal. This is usually a young animal soliciting food from their parents, brood hosts or other adults. However, the resource is sometimes non-food related or may be solicited by adult animals. Begging behavior is most widely studied in birds, however, mammals, amphibians, and invertebrates perform begging displays. Generally in food solicitation, begging behavior is instinctive, although in some instances it is learned.
Allofeeding is a type of food sharing behaviour observed in cooperatively breeding species of birds. Allofeeding refers to a parent, sibling or unrelated adult bird feeding altricial hatchlings, which are dependent on parental care for their survival. Allofeeding also refers to food sharing between adults of the same species. Allofeeding can occur between mates during mating rituals, courtship, egg laying or incubation, between peers of the same species, or as a form of parental care.