Daytrippers’ chips are killing species in protected areas

by Piter Kehoma Boll

Leia em português

There’s nothing as threatening to nature as humans, as we all know. A lot of species have become endangered and even extinct due to human influence all around the world. As an attempt to protect whatever is left, we have been creating protected areas where species should be able to live their lives without the dangers of humanity.

However, in order to raise awareness about the importance of preserving the biodiversity, most protected areas accept human visitors. Although it does have some effect to improve the visitors’ view about nature and its importance, there are a lot of undesired side effects. Humans walking through a forest cause noise that disturbs the local fauna and the soil compaction caused by walking can lead to changes in vegetation growth and soil drainage.

But another human behavior that appears to have serious consequences on biodiversity conservation is our tendency to carry food with us, such as snacks, and eat it anywhere. People visiting a protected area may eat something on the way through the woods or stop for a picnic. Many species love food remains left by humans and will thrive with them.

Two Steller’s jays in Big Basin Redwoods State Park. Photo by iNaturalist user kgerner.*

One species that benefits from human food is the Steller’s jay, Cyanocitta stelleri, a corvid that is common across the the west coast of North America. As a result, this species is not at all threatened at the moment and it tends even to follow humans because of the easy access to food. In the wild, this species is a generalist omnivore, feeding on seeds, fruits, invertebrates, eggs and small vertebrates, such as rodents and bird nestlings.

Another bird that can be found in the same areas as the Steller’s jay is the marbled murrelet Brachyramphus marmoratus, a small seabird. Different from most seabirds, the marbled murrelet does not nest in cliffs or burrows near the water but on branches of old-growth conifers. As a result, they may move up to 80 km inland to find a suitable place to nest. Different from the Steller’s jay, the marbled murrelet does not benefit from human snacks. On the contrary, they may be its ruin.

A young marbled murrelet found in the Big Basin Redwoods State Park. Photo by iNaturalist user basinbird.*

The marbled murrelet relies heavily on old forests to reproduce and the female lays only one egg per year, leading to a low reproductive rate. Due to the removal of old forests by humans, the marbled murrelet has lost a lot of its original habitat and is currently considered an endangered species.

One of the few remaining areas for this species to nest is located in the Big Basin Redwoods State Park in California. The park contains many options for camping, which means humans bringing food all the time. This attracts a lot of Steller’s jays, which feast on the crumbs and other remains, and reproduce explosively. When humans are not present, this increased population migrates toward new areas, sometimes following humans to the cities, or starts to feed on whatever is present in the park, and one of the most nutritious options are nestlings of the marbled murrelet.

With an already endagered population, the marbled murrelet is about to get extinct because our desire to walk through the woods is accidentally increasing the population of one of its main predators. Will we ever be able to have a good impact on this planet?

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Reference:

West EH, Brunk K, Peery MZ (2019) When protected areas produce source populations of overabundant species. Biological Conservation 238: 108220. doi: 10.1016/j.biocon.2019.108220

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High temperatures affect the judgement of zebra finches and of humans studying them

by Piter Kehoma Boll

Leia em Português

The zebra finch, Taeniopygia guttata, is an Australian bird that is often used as a model for behavioral studies focused on their vocalization.

Zebra finch (Taeniopygia guttata). Photo by Jim Bendon.*

Recently, a research team from Australia discovered a new call in this species and named it “incubation call”. This particular vocalization was identified as occurring during the last five days of incubation when one of the birds, either the male or the female, was alone with the eggs, and only when temperatures were above 26°C. This raised the hypothesis that this call is used by the parents to communicate to the embryos that the environmental temperature is high and that this information would be used by the nestlings to adapt their behavior and metabolism to higher temperatures.

An experimental study was conducted where eggs were kept in incubators under a constant temperature and exposed (test) or not (control) to recorded incubation calls. The results indicated that nestlings that were exposed to incubation calls grew faster in high temperatures than those that were not exposed to the calls. The mean difference in nestling mass between different temperatures and treatments was of about 2 g only, although the difference in mass between two randomly selected nestlings could be as much as 6 g. Additionally, the R² value of the analyses, which tells how much of the variation is explained by the measured variable, was only 0.1, i.e., temperature explained only 10% of the growth differences between different temperatures in both treatments.

Nestlings in a nest.

One of the most intriguing aspects, however, was the fact that the incubation call was produced at temperatures as low as 26°C, which is not particularly hot in the natural environment of the zebra finch. Thus, another team conducted new studies to understand better how and when the “incubation call” was produced. They decided to rename this call as the “v-call” because their shape is an inverted V in spectrograms. They discovered that the v-call is related to panting, when the birds breathes quickly with its bill open to help reduce body temperature and is likely a side effect of panting and not a deliberate directed call. It is also not produced only during the last 5 days of incubation, but during the whole incubation period and the chick rearing, and some birds are more likely to v-call than others. The results suggest that the v-call is unlikely to have evolved as an incubation call and is more likely a side effect of panting. There is, however, the possibility that embryos can use this information to modulate their growth, although more studies are needed.

Other recent studies with the zebra finch indicate that elevated temperatures can have negative effects on the bird’s reproductive fitness. Temperatures around 40°C reduce sperm quality in male zebra finches and reduce the ability of females to discriminate between songs produced by males of the same species and males of different, distantly related species. A combination of these two effects can lead to a severe decrease in reproductive success by reducing the mating events and reducing sperm ability to fertilize eggs.

A physiological modulation in embryos to deal with the adverse effects of higher temperatures, as suggested by the use of the v-calls, would be certainly benefitial. Maybe this is a behavior still under selection? Let’s see what further studies tell us.

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References:

Coomes CM, Danner RM, Derryberry EP (2019) Elevated temperatures reduce discrimination between conspecific and heterospecific sexual signals. Animal Behavior 147: 9–15. https://doi.org/10.1016/j.anbehav.2018.10.024

Hurley LL, McDiarmid CS, Friesen CR, Griffih SC, Rowe M (2018) Experimental heatwaves negatively impact sperm quality in the zebra finch. Proceedings of the Royal Society B: Biological Sciences 285(1871): 20172547. https://doi.org/10.1098/rspb.2017.2547

Mariette MM, Buchanan KL (2016) Prenatal acoustic communication programs offspring for high posthatching temperatures in a songbird. Science 353(6301): 812–814. https://doi.org/10.1126/science.aaf7049

McDiarmid CS, Naguib M, Griffith SC (2018) Calling in the heat: the zebra finch “incubation call” depends on heat but not reproductive stage. Behavioral Ecology 29(6): 1245–1254. https://doi.org/10.1093/beheco/ary123

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* This work is licensed under a Creative Commons Attribution-Share Alike 2.0 Generic License.

The Dying Melody: Habitat fragmentation is killing the songs of our birds

by Piter Kehoma Boll

Birds, especially passerine birds (those of the order Passeriformes) are known for their ability to produce complex and melodic calls, or songs, used for a variety of purposes. Who doesn’t love to hear the birds singing beautifully in the forest?

Passerine birds include two main groups: the Passeri (songbirds), also called Oscines, and the Tyranni (tyrants), also called Suboscines. Both groups are able to produce complex calls, but those of the Oscines are usually more smooth and melodic and sound less mechanic.

However, there is one more difference between the calls of both groups. The calls of the tyrants are genetically transmitted from the parents to the offspring, i.e., they do not need to learn how to sing with adult birds. Among the songbirds, on the other hand, the complexity of the call is largely culturally inherited, i.e., they learn how to sing with other birds of the same species.

The orange-billed sparrow is a songbird found in the Neotropical region. Photo by Francesco Veronesi.*

A recent study published in the journal Animal Behavior (see reference) analyzed the complexity of the calls of two passerine birds found in the forests of Costa Rica: a songbird, the orange-billed sparrow Arremon aurantiirostris, and a tyrant, the scale-crested pygmy tyrant, Lophotriccus pileatus.

The scale-crested pygmy tyrant is a tyrant found in the Neotropical region. Photo by Chris Jimenez.*

The team compared the complexity of the calls in different populations of each species living in forest fragments of different sizes. The conclusion was that, while fragment size did not affect the complexity of the call in the tyrant bird, it significantly affected the call of the songbird.

Populations of the orange-billed sparrow that live in smaller fragments show a less complex song than those living in larger fragments. As the call in this species is culturally transmitted, this reduction in complexity is most likely a result of cultural erosion. As smaller fragments only support smaller populations, the birds do not interact that much with other individuals of the same species while they are growing up, and as a result their song becomes simpler and simpler.

We, humans, are the ones to blame for that, as you may already know. Our irresponsible practices are not only reducing population size in other species, but are destroying their culture as well.

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Reference:

Hart, P. J.; Sebastián-González, E.; Tanimoto, A.; Thompson, A.; Speetjens, T.; Hopkins, M.; Atencio-Picado, M. (2018) Birdsong characteristics are related to fragment size in a neotropical forest. Animal Behavior 137: 45–52. https://doi.org/10.1016/j.anbehav.2017.12.020

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*
This work is licensed under a Creative Commons Attribution 2.0 Generic License.

Friday Fellow: Nothern Screamer

by Rafael Nascimento

A relative of the southern screamer and the horned screamer that is much less known is the northern screamer (Chauna chavaria). These three birds form the family Anhimidae, which, despite superficially not looking like, are relatives of the ducks and geese (previously they were thought to be relatives of the chickens, the Galliformes).

The northern screamer. Photo by Brodie Ferguson.*

Measuring 76 to 91 cm and being slightly smaller than the southern screamer, with which it shares the genus, the northern screamer is characterized by a darker overall plumage and a larger black mark on the neck. These birds are very vocal and remarkable because of their crests.

While the horned and the southern screamers have a wide distribution, the northern screamer is a rare bird and is considered “near threatened” by the IUCN. It can only be found in north Colombia an northwest Venezuela, inhabiting marshes, lakes and river banks of forest areas. Most of its food is composed by plant material, such as roots, leaves, sprouts and other parts of aquatic plants.

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References:

BirdLife International. 2015. Chauna chavaria. The IUCN Red List of Threatened Species 2015: e.T22679726A83833043. http://dx.doi.org/10.2305/IUCN.UK.2015-4.RLTS.T22679726A83833043.en. Acessado em 21 de abril de 2016.

Carboneras, C., Boesman, P., Kirwan, G.M. & Sharpe, C.J. (2016). Northern Screamer (Chauna chavaria). In: del Hoyo, J., Elliott, A., Sargatal, J., Christie, D.A. & de Juana, E. (eds.). Handbook of the Birds of the World Alive. Lynx Edicions, Barcelona. (Retrieved from http://www.hbw.com/node/52792 in April 21, 2016).

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*This image is licensed under a Creative Commons Attribution 2.0 Generic License.

Friday Fellow: Shoebill

by Piter Kehoma Boll

When I first saw a picture of this bird, many years ago, my first thought was that it could not be real. It looked like a character of an old Hanna-Barbera animation and not like a real creature.

A real bird or a cartoon character? Behold the shoebill! Photo by Olaf Oliviero Riemer.*

The shoebill (Balaeniceps rex), also known as whalehead or shoe-billed stork, is a large African bird originally thought to be closely related to the true storks, as its body somewhat resembles that of a stork. However, molecular studies concluded it to be more closely related to pelicans, as well as to herons and ibises (which previously were also considered to be closer to storks!).

As one can easily notice, the name shoebill comes from the bird’s massive bill. The pointed upper jaw and the sharp edges of the bill help the shoebill to capture prey and tear them to pieces. The most frequent prey are fish, but it may also consume frogs, snakes, small monitors and crocodiles, as well as, more rarely, turtles, rodents and small birds.With a height typically between 110 and 140 cm, but able to reach 150, the shoebill is a tall bird. Its wingspan is also big, reaching up to 260 cm.

Certainly an interesting bird to look at. Photo by wikimedia user Quartl.*

The shoebills are solitary birds and even in crowded areas they avoid to stay to close to each other.  They apparently love hippos, as the disturbance that these large beasts create in water help them to obtain food by forcing fish to the surface.

The IUCN lists the shoebill as ‘vulnerable’ and its major threats include habitat destruction and hunting. Currently there are about 5,000 to 8,000 individuals with a disconnected distribution along river basins in sub-Saharan Africa.

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References:

John, J. R. M.; Nahonyo, C. L.; Lee, W. S.; Msuya, C. A. 2013. Observations on nesting of shoebill Balaeniceps rex and wattled crane Bugeranus carunculatus in Malagarasi wetlands, western Tanzania. African Journal of Ecology, 51(1): 184-187. DOI: 10.1111/aje.12023

Wikipedia. Shoebill. Available at: <https://en.wikipedia.org/wiki/Shoebill&gt;. Access on January 13, 2016.

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* 
This work is licensed under a Creative Commons Attribution-ShareAlike 3.0 Unported License.

The Story of the Dwarf Rhea

by Rafael Nascimento

The family Rheidae is nowadays represented by two or three (according to different authors) species of rheas, large running flightless birds, similar to the African ostriches, but having three toes on each foot instead of two. The largest one, the common rhea Rhea americana, has five subspecies distributed from northeastern Brazil to eastern Argentina and including Bolivia, Paraguay and Uruguay. The other forms, earlier put in a separate genus, Pterocnemia, are R. pennata and R. tarapacensis (commonly known as Darwin’s rhea and Puna rhea, respectively). Darwin’s rhea, which helped the British naturalist in the elaboration of his theory of natural selection, lives in the Argentinean and Chilean Patagonia. The systematic situation of the Puna rhea (and its possible subspecies), which is found in the area where Peru, Bolivia, Chile and Argentina meet, is not yet clear, and currently it is considered a distinct form based on some physical features, but more clarifying studies are necessary.

Beside these current forms and some fossil species, such as Opisthodactylus horacioperezi and Hinasuri nehensis, respectively from the Argentinian Miocene and Pliocene, another species was described in 1894 by the British Naturalist Richard Lydekker based on a small egg: Rhea nana – therefore representing a possible fourth rhea species living in historical times.

Richard Lydekker, ca 1900.

Following you can see the original text published in the journal Proceedings of the Zoological Society of London from 1894, with comments regarding this possible new species:

“Mr. R. Lydekker exhibited photographs and a model of a unique egg, the original of which had been obtained many years ago in Southern Patagonia, and now preserved in the Museum at La Plata. If not an abnormal specimen, it could not be assigned to any known species of bird.

When travelling in the district where the specimen was obtained, Dr. P. Moreno, Director of the Museum at La Plata, many years ago saw numbers of small Ratite birds, which he at first took to be small Rheas. By the natives, to whom they were well known, he was, however, assured that they were adult birds, allied to the Rheas. Desirous of confirming this information, Dr. Moreno applied to a friend acquainted with the district; who replied that not only did he well know the birds, but that he possessed an egg, that egg being the original specimen of which a model was now exhibited.

Assuming the egg to be a normal one, Mr. Lydekker was of opinion that, taken in connexion with the evidence of two independent witnesses who had been the birds, it pointed to the existence in Southern Patagonia of a small unknown Ratite bird more or less nearly allied to the Rheas.”

Illustration of Darwin’s Rhea by John Gould, 1841.

Until today, however, no other similar egg or adult bird of a species different from the three already mentioned has been found. When we deal with potentially extinct species, only know by scarce reports or aberrant specimens, one must watch the data through a skeptical point of view. We need to be certain that those are not variations within the species or a witness confusion. The lack of extensive comparative material due to the date of the descriptions must also be taken into account, as well as the constant advancements in our understanding of science.

Normal egg of R. pennata, at Museum Wiesbaden (Germany). Photo by Klaus Rassinger/Gerhard Cammerer.

This egg is currently treated as an aberrant form of a Rhea pennata egg. The model cited by Lydekker, made of wax, is found in the Tring Natural History Museu, England.

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del Hoyo, J., Collar, N. & Garcia, E.F.J. (2015) Puna Rhea (Rhea tarapacensis). In: del Hoyo, J., Elliott, A., Sargatal, J., Christie, D.A. & de Juana, E. (eds.). Handbook of the Birds of the World Alive. Lynx Edicions, Barcelona. (retrieved from http://www.hbw.com/node/467080 on 24 December 2015).

Folch, A., Jutglar, F., Garcia, E.F.J. & Boesman, P. (2015) Greater Rhea (Rhea americana). In: del Hoyo, J., Elliott, A., Sargatal, J., Christie, D.A. & de Juana, E. (eds.). Handbook of the Birds of the World Alive. Lynx Edicions, Barcelona. (retrieved from http://www.hbw.com/node/52399 on 24 December 2015).

Folch, A., Christie, D.A., Jutglar, F. & Garcia, E.F.J. (2015) Lesser Rhea (Rhea pennata). In: del Hoyo, J., Elliott, A., Sargatal, J., Christie, D.A. & de Juana, E. (eds.). Handbook of the Birds of the World Alive. Lynx Edicions, Barcelona. (retrieved from http://www.hbw.com/node/52400 on 24 December 2015).

Hume, J. P.; Walters, M. (2012) Extinct Birds. T & AD Poyser. Londres.

Knox, A. G.; Walters M. P. (1994) Extinct and Endangered Birds in the collections of The Natural History Museum. British Ornithologists’ Club Occasional Publications.

Lydekker, R. (1894) Exhibition of, and remarks upon, a photograph and model of an egg from Southern Patagonia in the La Plata Museum. Proceedings of the Zoological Society of London (1894): 654.

Biological fight: the case of artificial stimuli in behavior research

by Piter Kehoma Boll

The study of animal behavior is an important approach to understand several aspects on the ecology and the evolution of living beings, both from the analyzed animals themselves and the species with which they interact. For example, understanding how a bee recognizes a flower as a food source and how it approaches it may explain a lot about the physiology and the evolution of the flower and vice-versa, thus clarifying why such a combination of characters is the one that is found in the current population.

As with virtually any type of study in biology, a research may be done with sampling or experiments. By sampling you obtain non-manipulated information directly from the environment. You collect or observe a small sample of the whole and infer the general situation of the population based on it. On the other hand, in an experiment you manipulate the environment and watches how the organisms will react to the different stimuli presented to them and, from this, you develop your conclusion.

For example, if you want to know what a species of frog eats, you may find out by sampling, observing some frogs in the wild while they feed or capturing some and examining their stomach contents. You may also offer them different kinds of food, either in the environment or in the lab, and observe how the frogs reacts to each one.

Thus, in experiments you control the stimuli the species receives from the environment. This is the point where things start to get nasty. May the stimuli have artificial elements, i.e., elements that cannot be found by the animal in its habitat?

The opinions about it are divergent and recently led to a “formal fight” published in the journal Ethology:

On one side is a group of researchers from several universities around the world (Hauber et al., 2015) that defends the use of artificial stimuli to analyze behavior. They use as a model the studies on the rejection of eggs of parasitic birds by parasitized birds, a well-studied phenomenon.

First, let us contextualize this phenomenon briefly:

Several bird species, mainly cuckoos, do not incubate their own eggs. Instead of doing it, they lay them in the nests of birds of other species and hope that the poor creatures incubate and later feed the chicks as if they were their own. As a result, natural selection favors cuckoos whose eggs are more similar to the ones of the parasitized bird and also favors the parasitized birds that better distinguish their eggs from the ones of the intruders. It is a typical evolutionary race.

Find the intruder. The similarity between the egg of the parasite and the parasitized can vary greatly. Photos by wikipedia user Galawebdesign (left)* and by Grüner Flip (right).

In experimental studies on egg rejection by parasitized birds, it is common to use artificial eggs that exaggerate features of natural eggs. This includes, for example, changing color and size in order to understand which is the most relevant for the bird to recognize the eggs as being yours or not. However, can we trust the results of such experiments using artificial elements?

Haubert et al. (2015) think that we can. Their arguments in favor of the use of such artificial stimuli are the following:

1. Real eggs of the studied species are difficult to get in large quantities and could cause significant impacts over the populations if used. So, artificial eggs ensure the integrity of populations.
2. It is difficult to get a set of natural eggs similar enough to allow the necessary repetitions to validate the test. After all, a result is only considered valid if it is recorded several times in face of the same stimulus. Artificial eggs allow identical copies and, thus, true repetitions.
3. Natural eggs vary in several aspects at the same time, such as color, size, form, texture… In artificial eggs it is possible to control these aspects and allow only one to show free variation, so isolating the influence of each one during the recognition by the bird.
4. A variation beyond the ones found in the wild may help to find populations with different degrees of perception of strange eggs and consequently where are the sites of higher selective pressure.

Original eggs of the parasitized species painted to exaggerate color features. Photos by István Zsoldos. Extracted from Moskát et al. 2010.

Not everyone looks so favorably to such an unrestrained use of artificial stimuli. Soon after the opinion of Hauber et al. we find the reply of David C. Lahti (2015) who faces all by himself the “artificialist” army. Lahti shows some aversion to such exaggerate use of artificial elements that many times are not used in a responsible manner.

Suggesting a more restrict use of artificial elements, he argues the following:

1. Our perception of the environment is different from the one of the species we are studying. For instance, a bird sees a much wider range of colors than we do. When we paint an artificial egg black and white in order to simulate a natural black and white egg, we don’t know whether the bird really sees both eggs with the same colors. So, while we suppose that the eggs look similar by our perception, the reality from the bird’s point of view can be very different.
2. When we try to create a set of artificial eggs that vary in only one aspect, such as the size of the spots on the shell, for instance, in order to control the influence of this stimulus only, we always end up including secondary stimuli that are not measured, such as the paint used to make the spots. If the birds shows a different response to eggs with small spots (natural ones) when compared to eggs with large spots (artificial ones), how can we know that the difference was not caused by the perception of the paint, either chemically or visually, by the animal? It would be necessary to perform tests that would discard this possibility, but it does not happen usually.
3. Exaggerated artificial stimuli may go beyond the species’ range of recognition. An egg with a color too different from any color variation found in the environment could cause the bird not to see it as an egg, which would lead to problems in the interpretation of the results.

Concerning this last argument, Hauber et al. emphasize that is important to take care on a priori interpretations on the species behavior. That is to say, we cannot guess what the bird is thinking. The fact that the bird removes the parasite’s eggs from the nest or not does not mean that it is capable of recognize the egg as an intruder, or even as an egg. The way the bird interprets the stimulus is not as important as its response to it.

Therefore, we can conclude that artificial stimuli can be advantageous and in several circumstances they are the only available alternative. It is important, however, to take care with their use and try to be sure that secondary features, generally neglected, are not considered important by the animal.

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References:

Hauber, M.; Tong, L.; Bán, M.; Croston, R.; Grim, T.; Waterhouse, G.; Shawkey, M.; Barron, A.; & Moskát, C. 2015. The Value of Artificial Stimuli in Behavioral Research: Making the Case for Egg Rejection Studies in Avian Brood Parasitism Ethology, 121 (6), 521-528 DOI: 10.1111/eth.12359

Lahti, D. 2015. The Limits of Artificial Stimuli in Behavioral Research: The Umwelt Gamble Ethology, 121 (6), 529-537 DOI: 10.1111/eth.12361

Moskat, C.; Ban, M.; Szekely, T.; Komdeur, J.; Lucassen, R.; van Boheemen, L.; & Hauber, M. 2010. Discordancy or template-based recognition? Dissecting the cognitive basis of the rejection of foreign eggs in hosts of avian brood parasites Journal of Experimental Biology, 213 (11), 1976-1983 DOI: 10.1242/​jeb.040394

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* 
This work is licensed under a Creative Commons Attribution-ShareAlike 3.0 Unported License.

Friday Fellow: Tropical Kingbird

by Piter Kehoma Boll

This is the first bird featured in Friday Fellow and I have chosen it for a special reason: it’s binomial name is Tyrannus melancholicus, the melancholic tyrant. Isn’t it almost poetic?

Found from southern United States to the northern half of Argentina, the Tropical Kingbird, known as sirirí or suiriri in Spanish and Portuguese, is very well adapted to human disturbed areas, so it is easily spotted along roads or at gardens and parks. Populations inhabiting areas of great seasonality usually migrate to warmer areas, mainly towards southern United States during the winter in the southern hemisphere.

Tropical kingbird in São Paulo, Brazil. Photo by Dario Sanches*. Extracted from commons.wikimedia.org

Tropical Kingbirds are mainly predators, capturing insects intercepted in flight. They don’t seem to be very sensitive to chemical defenses of butterflies, eating even some unpalatable ones and species with similar color patterns, though some species highly unpalatable are indeed rejected. Ocasionally they may also eat fruits.

During the breeding season, they form couples and build together a bowl-shaped nest using small branches, straw and nylon and plastic threads. The female usually lays three eggs in the nest and both birds incubate them and take care of the chicks.

As a consequenceof its adaptability to humans, it is not endangered at all, at least until now, and has a status of Least Concern (LC) by IUCN.

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References:

Cintra, R. 1997. Spatial Distribution and Foraging Tactics of Tyrant Flycatchers in Two Habitats in the Brazilian Amazon. Studies on Neotropical Fauna and Environment, 32 (1), 17-27 DOI: 10.1076/snfe.32.1.17.13459

Legal, E. 2007. Aspectos da nidificação do siriri, Tyrannus melancholicus (Vieillot, 1819), (Aves, Tyrannidae) em Santa Catarina. Atualidades Ornitológicas On-line, 140, 51-52

Pinheiro, C. E. G. 1996. Palatablility and escaping ability in Neotropical butterflies: tests with wild kingbirds (Tyrannus melancholicus, Tyrannidae) Biological Journal of the Linnean Society, 59 (4), 351-365 DOI: 10.1111/j.1095-8312.1996.tb01471.x

Wikipedia. Tropical Kingbird. Available online at < http://en.wikipedia.org/wiki/Tropical_Kingbird >. Access on March 27, 2014.

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* 
This work is licensed under a Creative Commons Attribution-ShareAlike 3.0 Unported License.

A 120-years-old Legend

by Rafael Silva do Nascimento

Long living pets that could go along with their owners for years have always been an attraction, as one can see by the popularity of turtles as pets, as well as psittacids, which are also vivid and interactive. Animals tend to live longer in captivity, not being exposed to the dangers of the “wild”. Some, however, exceed the expectations concerning longevity and become very curious characters. One of those was a cockatoo that lived more than a century in Australia, between the 18^th and 20^th centuries.

Called Cocky Bennet, a sulphur-crested cockatoo (Cacatua galerita), he stood out not by the age he would reach, but for its unusual physical features. Born in 1796 (according to Brisbane’s weekly summary, The Queenslander), near Sydney, he was removed from his nest on a eucalypt by a local farmer. As the years passed, he started to lose the feathers, looking like a plucked chicken with a wrinkled skin. Moreover, his upper mandible had an extraordinary long tip, so that he could only eat mashed food. Such abnormalities are typical of the psittacine beak and feather disease, caused by a circovirid virus, which also lowers the animal’s immunity against the effects of other viruses and bacteria.

Cocky Bennet with an age of 115 in his cage, 1911. Photo from the archive of State Library of Victoria, Australia.

The bird spent his first 78 years travelling the world with Captain Ellis, his owner. Following the death of the captain, he was bequeathed to a Mr. and Mrs. Bowden. With the death of Mr. Bownden in 1889, his wife soon married Charles Bennet, with the couple then moving to Tom Ugly’s Point, Blakehurst, in 1891, where Mr. Bennet became the licensee of the Sea Breeze Hotel.

Popular, Cocky lived in the hotel for most of his last 25 years. Talkative, his repertory included phrases like “one feather more and I’ll fly” and “one at a time, gentlemen, please”, when harassed by other birds. Cocky was more talkative and with more lurid language after being given a “sip of strong brew”.  He received the visitors while moving and jumbling at the top of his cage in the hotel’s front verandah.

Cocky Bennet with an age of 118, 1914. Photo from the archive of Sutherland Shire Libraries, Australia, used with permission.

Despite being affected by the disease, he passed away only in May 1916, being the longest living psittacid registered in Australia. As there are no sources indicating in which month Cocky was removed from his nest, it’s not possible to determine if he was already 120 years old or still 119. Sulphur-crested cockatoos, in Sydney, breed from August to January and the eggs hatch after about 25 days. So, assuming that he wasn’t a newborn (for he possibly wouldn’t have survived if removed from the nest as soon as he left the egg), the farmer probably took him between about late September and late February. Back in the day, his age was estabilished by ornithologists counting the growth rings of his beak, concluding he was 120 years old, give or tak a year. The mean lifespan for his species is 70 years.

Cocky Bennet, 1914. Photo from the archive of Sutherland Shire Libraries, Australia, used with permission.

After his death, The Sydney Morning Herald published (in 1916) the following note:

A Venerable Cockatoo

“Cocky Bennet,” a sulphur-crested Australian cockatoo, died on Friday in his 120^th year at Canterbury. This age is a record in longevity for an Australian parrot so far as the officials records are concerned. For many years this bird was in the possession of Mrs. Sarah Bennet, the licensee of the Sea Breeze Hotel, at Tom Ugly’s Point. When she left there, about 12 months ago, she transferred the parrot to her nephew, Mr. Murdoch Alexander Wagschall, at Woolpack Hotel, Canterbury. The old bird was absolutely featherless for the last 20 years, but it maintained its “patter” till the day before its death. “Cocky Bennet” was a great traveller, and is said to have journeyed seven times round the world. Mr. Wagschall has arranged to have remains of this historic parrot preserved by a taxidermist.”

Accordng to W. A. Easterling (The Sydney Morning Herald from July 9 1984), a distant nephew of Mrs. Bennet, the bird was stuffed and mounted by the firm Tost and Rohu and set in a glass case. It remained at the hotel until the late 1920s or early 1930s, when his grandmother, Mrs. P.Wagschall (whose husband operated the old Woolpack Hotel at Canterbury), left the hotel business. Then handed to his mother, Cocky hung in their dining room for more than 40 years, where it he became used for the family members but the visitor were unnerved by the baleful glare of the relic. His late wife once commented that she was in two minds about marrying him lest he inherit the old horror. After his family home was sold, his sister handed Cocky’s remains to the Kogarah Historical Society in their museum at Carss Cottage in Carss Bush Park, together with such documents that they had.

Easterling also notes that The Sutherland Council library held in May 1973 a feature display about the bird, and its researches brought forth much more historical information than was known to his part of the family. The matter was also thrased out in Column 8 (Herald, May 12, 1973), when the impostor specimen was displayed at the Sea Breeze Hotel, where he understand that it was acquired from a private museum at Kurnell and had been shown as Cocky’s alleged remains.

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References:

Centre for Fortean Zoology Australia. 2011. From the archives: A Venerable Cockatoo (1916). Available on-line at: <www.cfzaustralia.com/2011/09/from-archives-venerable-cockatoo-1916.html>. Acess on February 13, 2012.

Grellis, A. 2008. Blakehurst: Cocky Bennet. Dictionary of Sydney. Available on-line at: <www.dictionaryofsydney.org/entry/blakehurst>. Acess on February 14, 2012.

Kable, F. J. & Easterling, W. A. 1984. Fate of the real Cocky Bennet. The Sydney Morning Herald, Sydney, Australia, July 9, 1984, p. 8.

 

Kwek, G. 2011. Sydney’s old crock of a cockie was a legend at 120. The Sidney Morning Herald. Available on-line at: <www.smh.com.au/environment/animals/sydneys-old-crock-of-a-cockie-was-a-legend-at-120-20110831-1jkz2.html>. Acess on Februrary 13, 2012.

 

Meinhardt, J. 2011. The Birds. Oh Snap! Available on-line at: <jocelot.blogspot.com/2011/04/birds.html>. Acess on February 13, 2012.

 

The Macaw of Dominica

by Rafael Silva do Nascimento

Talking and exuberant-colored birds always exerted a strong fascination over human beings, and with me it couldn’t be different. Besides, the curiosity that something rare or lost arouses is an important factor to define a theme of interest to someone. Those two combined factors are the foundation that sustains a great interest on my part in extinct species of psittacids, mainly in those ones with little evidence of their doubtful existence.

Several psittacid species inhabitant of island paradises were extinct in the last centuries mainly due to hunting for food, trade to become pets and habitat loss. In this post I’ll deal with a specific species that’s said to have inhabited the Dominica Island, in the Lesser Antilles (Caribbean).

Dominica was firstly inhabited by the Caribbean Indians and later colonized by French and English. Hunting by the Indians is usually sustainable, not representing a great threat for the species.

The colonization by the Europeans, however, has been proved devastating, a common scenario not only in those islands, but also in several other points of the planet.

A forest in Dominica. Photo by Dirk.heldmaier, from Wikipedia.

The Dominican Green-and-Yellow Macaw (also known as Atwood’s Macaw or simply Dominican Macaw), Ara atwoodi, is known only from the report of Thomas Atwood. In his work “The history of the island of Dominica. : Containing a description of its situation, extent, climate, mountains, rivers, natural productions, &c. &c. Together with an account of the civil government, trade, laws, customs, and manners, of the different inhabitants of that island. Its conquest by the French, and restoration to the British dominions” from 1791, Atwood describes the local fauna, whose elements can be associated to the species currently known to the region, with the exception of a kind of psittacid no more found there and that differs from the other ones known in the island (Amazona arausiaca and A. imperialis, which Atwood probably considered a single species in his description) or anywhere else on the planet. The following is the excerpt, adapted to the modern English:

‘’The macaw is of the parrot kind, but larger than the common parrot, and makes a more disagreeable, harsh noise. They are in great plenty, as are also parrots in this island; have both of them a delightful green and yellow plumage, with a scarlet-colored fleshy substance from the ears to the root of the bill, of which color is likewise the chief feathers of their wings and tails. They breed on the tops of the highest trees, where they feed on the berries in great numbers together; and are easily discovered by their loud chattering noise, which at a distance resembles human voices. The macaws cannot be taught to articulate words; but the parrots of this country may, by taking pains with them when caught young. The flesh of both is eat, but being very very fat, it wastes in roasting, and eats dry and insipid; for which reason, they are chiefly used to make soup of, which is accounted very nutritive.’’

Atwood's Description in ''The History of the Island of Dominica'', 1791.

It’s believed that it became extinct by the end of the 18^th century or beginning of the 19^th century. As there are no extant species of green and yellow plumage (excluding hybrids induced by humans), Austin Hobart Clark assumed that it belonged to a species not yet known to science, firstly including it in Ara guadeloupensis (which is said to inhabit the neighboring island Guadeloupe). With the discovery of Atwood’s account, it was considered distinct, receiving the status of species in 1908.

Considered a hypothetical species by most authors, Ara atwoodi usually isn’t included in non-specific publications that mention recently extinct macaws, which almost always only mention the Cuban macaw Ara tricolor, for being the only one known from preserved specimens, and subfossil forms like A. autocthones. Joseph Forshaw highlight that’s not even safe to associate the species to the genus Ara, due to the absence of specimens, either stuffed or bones, or even illustrations. The association was made by deduction, based on the term “mackaw” used by Atwood, where Clark notices that “his macaw is a bona fide member of the genus Ara”. That, however, didn’t exclude the possibility of being a similar but separated genus that evolved by isolation in the island.

Reconstruction following the picture published in David Day's ''The Doomsday Book of Animals''. Picture by Rafael Silva do Nascimento, 2009.

From the excerpt describing its physical characteristics and based in close species, some reconstructions of how it looked started to appear, though in shyer steps than in other more popular extinct birds. The most widely known is the one present in David Day’s work “The Doomsday Book of Animals” (1981), which depicts a macaw well distinguished from the species whose appearance was known, not having the portion of bare skin on its face, consisting merely of a closed portion, but following the color pattern described by Atwood. Most posterior reconstructions are based on this picture. Other obscure species with a similar history are portrayed, like Ara erythrocephalus from Jamaica, which was also reported having green and yellow feathers, but with a red head. The color as it was described and the observation of extant species suggest a pattern similar to the one found in Ara ararauna and maybe in A. martinicus from the neighbor island Martinica (another hypothetical extinct species), with blue replaced by green. Also reported from Jamaica, but not creditable by most sources, is A. erythrurus, said to be similar to A. ararauna, but with an entirely red tail. Julian Hume in his book “Extinct Birds” to be released in February 2012, which also have Michael Walters as author, portrayed the species according to this idea, however without having the portion of bare skin on the face painted red, but only the forehead of this color. Since I didn’t have access to the work of Walters and Hume, I’m not aware of the reason for such a reconstruction, but considering that the reddish facial portion, usually seen as a distinct feature of A. atwoodi, may be simply excitation as observed in A. ambiguus, A. militaris and A. rubrogenys, this macaw may have been represented in a “calm” situation. Both A. ararauna and A. glaucogularis can show traces of redness on the face, being more evident in the last, so if A. atwoodi was truly a close relative, this feature might be more advanced in this species. A color pattern that recalls the described by Atwood is found in the pet market as in the hybrids Catalina (A. ararauna x A. macao) and Harlequin (A. ararauna x A. chloropterus), where the back is green and the belly varies from shades of yellow to bright orange.

I've made this reconstruction following the theory that A. atwoodi was closely related to A. ararauna. Some elements, such as the black patch below the bill, are highly speculative.

While I see sufficient evidences to declare the existence of a different form of macaw that once inhabited Dominica, its real appearance will remain a mystery until new evidences came to the surface, whether they are lost reports or subfossil bones.

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References:

Atwood, T. 1791: The History of the Island of Dominica. London: Frank Cass and Co.

BirdLife International (2011) Species factsheet: Ara atwoodi. Available on-line in: < www.birdlife.org/datazone/speciesfactsheet.php?id=30080>.  Acess on December 6^th, 2011.

Clark, A. H. 1908. The Macaw of Dominica Auk, 25, 309-311

Forshaw, J. M. & Cooper, W. T. 1977: Parrots of the World. T.F.H. Publications, Inc. New Jersey.

Fuller, E. 1987: Extinct Birds. Facts on Files Publications. New York.

Maas, P. H. J. 2007: Dominican Green-and-Yellow Macaw. In: TSEW. The Sixth Extinction Website. Available on-line in: <www.petermaas.nl/extinct/speciesinfo/dominicanmacaw.htm>. Acess on December 6^th, 2011.

Many-feathers. Catalina Macaw. Available on-line in: < www.many-feathers.com/Catalina-Macaw.htm>. Acess on December 6^th, 2011.

Rothschild, W. 1907: Extinct Birds. Hutchison, London.

Williams, M. I. & Steadman, D. V. 2001: The historic and prehistoric distribution of parrots (Psittacidae) in the West Indies. Pp 175-489 in Biogeography of the West Indies: patterns and perspectives. 2nd ed. (Woods, C. A. & F. E. Sergile, eds.) Boca Raton, FL: CRC Press.