Bad at Goodbyes

Rough Transcript

Intro 00:05

Welcome to Bad at Goodbyes.

On today’s show we consider the Giant Ibis.

Species Information 02:05

The Giant Ibis is a critically endangered avian native to Southeast Asia, specifically Cambodia, Laos, and Vietnam.

 

It is the largest of the ibis family, approximately 3.5 feet long with a wingspan of about 5.5 feet and weighing roughly 9 pounds.

 

It has dark, grayish brown plumage, with more pale silver gray highlights on the wingtips. Its head, is naked, no feathers, with wrinkled grey-brown skin. It has dark red eyes and a long yellow-brown decurved bill that can reach lengths of over 9 inches. Um, decurved means curved downward, so the bill is slightly hooked, toward the earth. It has a long neck, and long, bright, red-orange legs. The feet have four clawed digits, three talons facing forward and one hallux facing backward, this toe arrangement is called anisodactyl.

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In the dream, all is song.

 

Not like a musical, but like a perspective shift, like hearing an extra dimension, the wind is song, the shopkeeper sweeping is song, the many tourists asking directions to the Brooklyn Bridge are song, a bike bell is song, ambulance is song, the vibration of my phone when I’m hoping for your text, is song, soup near boiling on the stove is song, autumn leaves underfoot are song, a dog barks its song, a bird sings. And so, when I ask that classic human question: “Why does a bird sing?” the Giant Ibis, with a voice like a grouchy Boston cabbie, calls back to me. “Because all is song.” We hatch from the long silence, into a life of singing, and then return to silence again. We make harmony and dissonance, the breath chorus of living, we really move air, all together for a time.

 

In the dream.

 

Another philosophical Ibis, in the dream.

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The “dawn chorus” is the phrase scientists use to describe the crescendo of bird song that happens each day in the young morning light. Birds are waking up and need to communicate with each other about territory, mating, and potential threats. In these early hours it’s too dark for effective foraging, but light enough for birds to see each other and assess their surroundings.  This makes dawn a safe time for sharing information without being overly exposed to predator threats.

 

The Giant Ibis lends its uh, tenor to the dawn chorus as well. I’d like to play two field recordings for you now, both from Cambodia, the first by recordist Eang Samnang is from a summer morning at 5am, and the second from Patrik Åberg winter at 6am.

 

[field recordings]

 

The Giant Ibis is diurnal, meaning active during the day. Generally mornings and late afternoons are peak foraging times. It is a carnivore, consuming aquatic invertebrates, such as worms, crab, snails, and insects, and small vertebrates like fish, frogs, and eels, extracted from shallow water and mud using that long, decurved bill.

 

Their bill has a specialized sense organ, called the bill-tip organ, that is a collection of mechanoreceptors at the bill’s tip. Mechanoreceptors are sensory receptors that detect stimuli like pressure, touch, and vibration. And so the Ibis is able to find food it cannot see, beneath the water’s surface and in the mud, by probing with its bill, and detecting movement or presence of prey with its bill-tip organ.

 

Briefly let’s connect three other bits of Giant Ibis anatomy to this feeding strategy. Its particularly long legs allow it to wade into small pools and marshlands and not get its feathers overly soaked. Relatedly, the lack of feathers on its head and neck are a likely adaptation to it like putting its head in the mud all the time, feathers would get like waterlogged or like crusted with dirt. And lastly the Giant Ibis has been observed using its clawed talons to dig, to root around in the mud to unearth potential prey.

 

Giant Ibis are generally solitary or forage in pairs, but may occasionally flock in small groups of less than ten when feeding.

 

They do form monogamous mating pair bonds that can last across several mating seasons, and sometimes, for life.

 

I could not find much information about mating and mating rituals other than a mention that males may perform wing-flapping and bowing actions to attract a mate.

 

Once mated though, we know that the Giant Ibis prefers to nest in tall trees, generally Dipterocarp trees. The nests are large platforms constructed from sticks and branches, typically situated high in the canopy for protection from predators. Nest building is a collaborative effort between the male and female pair.

 

The female lays a clutch of two eggs. The eggs are incubated by both parents, over an incubation period that lasts about a month. We, accurately, think of avian incubation as like bird sitting on egg, there is a little more going on there. The main goal is temperature regulation, transferring body heat from the parent to the egg, maintaining an optimal temperature for embryonic development. Maintaining nest humidity is also important, too much humidity can suffocate the developing embryo, while too little can cause dehydration and prevent proper hatching. Parents regularly turn the eggs to ensure even heat and humidity and prevent the embryo from sticking to one side of the shell membrane. And of course the parent bird is also protecting the eggs from predators and adverse weather conditions.

 

Giant Ibis are altricial, meaning they are born helpless, and both parents actively participate in feed and care of newly hatched chicks.

 

And so a family unit consists of the breeding pair and their offspring. Parents protecting and nurturing their young, providing regurgitated food, until they are old enough to forage independently. Young Giant Ibis remain dependent on their parents for several months, gradually learning to survive on their own.

 

It takes roughly 4 years for a Giant Ibis to reach reproductive maturity. They can live as long as 22 years.

 

The Giant Ibis is native to Southeast Asia, with most populations found in north eastern Cambodia, with a few occasional sightings in southern Laos, and western Vietnam.

 

This is a lowland plains habitat of seasonally flooded grasslands, so a mix of open grassy plains, with patches of forest and more dense vegetation, that, during the wet season, become inundated with water, creating networks of temporary pools and marshlands; these waterholes are an ideal foraging habitat for the Ibis.

 

The climate is tropical, summer temps reach in the high 90s°F, while winter temperatures rarely drop below 65°F.  May to October sees heavy rains, with an abundant annual rainfall of up to 80 inches.

 

The Giant Ibis shares its habitat with:

Sun Bear, Tiger Beetle, Eurasian Wild Pig, Malayan Porcupine, Clouded Leopard, Siamese Crocodile, Grey-Headed Fish Eagle, Small Asian Mongoose, Eld’s Deer, Water Monitor, Yellow-Throated Marten, Green Crested Lizard, Great Hornbill, Sunda Pangolin, Asian Elephant, Jungle Cat, Reticulated Python, Green Peafowl, Golden Jackal, Slender-Billed Vulture, and many many more.

 

Historically the Giant Ibis was found across southeast Asia, but over the course of the 19th and 20th century their population diminished due to human induced habitat reduction and human predation. Specifically wetland drainage for agriculture, mass deforestation for construction material and development, and hunting and egg collection for food.

 

Some of these threats persist. Today, habitat destruction and degradation remains a significant threat. Large-scale land transformation for rubber, teak, and cassava plantations continue to reduce Giant Ibis natural habitat.

 

And although it is illegal, hunting and trapping still occurs, driven by demand for wild meat and traditional medicine.

 

The use of pesticides in agriculture indirectly affects the Giant Ibis by contaminating the water of their food sources.

 

And human induced climate change is a looming threat, altering rainfall patterns and increasing the frequency of extreme weather like drought and flood.

 

Fortunately most of the current Giant Ibis population resides on protected land, in wildlife sanctuaries and protected forests. The Cambodian government enacted legal protection for the bird in 2007 and The Forestry Administration and Ministry of Environment in Cambodia have embarked on a decade-long plan to protect Giant Ibis habitat, to implement active interventions to increase survival and breeding success, and to conduct continued research to inform conservation policy.

 

For example, restoration of previously-cleared land is being explored. Public outreach programs to discourage illegal poaching have shown success, and conservationists are monitoring and intervening on nesting sites.

 

With a such small population even “natural” predation is an extinction threat for the Giant Ibis. So scientists conducted a predator-exclusion experiment in 2005 in which a 3 foot wide plastic belt was fixed to the lower trunk of Giant Ibis nest-trees. This belt was hard and smooth enough to prevent climbing by any animals (like the Common Palm Civet) that prey upon ibis eggs. The result was a nearly doubled survival rate for the eggs in nests on the treated trunks.

 

A federal program is being explored to provide clean water to human communities near Giant Ibis habitats. In the recent past, during particularly dry seasons, humans would source water from Ibis waterholes and marshlands. The government is exploring shipping in water to prevent this destructive practice.

 

The Giant Ibis was declared the National Bird of Cambodia in 2005.

 

Nevertheless the Giant Ibis has been considered critically endangered on the IUCN Red List since 1994 and their population is currently in decline.

 

Our most recent counts estimate less than 200 Giant Ibis remain in the wild.

Citations 25:02

Information for today’s show about the Giant Ibis was compiled from:

 

Bird Conservation International vol. 19, no. 1 (2009): 77–82. Keo, Omaliss, Nigel J. Collar, And William J. Sutherland. “Nest Protectors Provide a Cost-Effective Means of Increasing Breeding Success in Giant Ibis Thaumatibis Gigantea.” – https://doi.org/10.1017/S0959270908008319 

 

BirdingASIA no. 9: 100-106. 2008. Keo, O. “Ecology and conservation of the Giant Ibis Thaumatibis gigantea in Cambodia.” – https://static1.squarespace.com/static/5c1a9e03f407b482a158da87/t/5c4337d3bba223672012ea0e/1547909077032/omaliss-giantibis.pdf

 

BirdLife International. (2024) Species factsheet: Giant Ibis Thaumatibis gigantea. –  https://datazone.birdlife.org/species/factsheet/giant-ibis-thaumatibis-gigantea 

 

Birds of the World (J. del Hoyo, A. Elliott, J. Sargatal, D. A. Christie, and E. de Juana, Editors). Cornell Lab of Ornithology, Ithaca, NY, USA. Version 1.0. Matheu, E., J. del Hoyo, G. M. Kirwan, E. Garcia, and C. J. Sharpe (2020). “Giant Ibis (Pseudibis gigantea)”.  – https://doi.org/10.2173/bow.giaibi1.01 

 

Cambodian Journal of Natural History. Vol. 1. 2017 (1): 63–75. Suzuki, A.; Thong, S.; Tan, S.; Iwata, A. “Camera trapping of large mammals in Chhep Wildlife Sanctuary, northern Cambodia”. – https://rupp.edu.kh/cjnh/journal/CJNH-2017-1/CJNH%202017(1)%201%20Full%20Issue.pdf 

 

Conservation Biology, Vol. 34: 1252-1261. (2020). Bird, J.P., Martin, R., Akçakaya, H.R., Gilroy, J., Burfield, I.J., Garnett, S.T., Symes, A., Taylor, J., Şekercioğlu, Ç.H. and Butchart, S.H.M. “Generation lengths of the world’s birds and their implications for extinction risk”. – https://doi.org/10.1111/cobi.13486 

 

Conservation Leadership Programme – https://www.conservationleadershipprogramme.org/project/giant-ibis-cambodia/ 

 

Forktail, the Journal of Asian Ornithology: no. 28 August 2012. H. L. Wright, N. J. Collar, I. R. Lake, Bou Vorsak & P. M. Dolman. “Foraging ecology of sympatric White-shouldered Ibis Pseudibis davisoni and Giant Ibis Thaumatibis gigantea in northern Cambodia”. – https://static1.squarespace.com/static/5c1a9e03f407b482a158da87/t/5c2124d8c2241b2a02dcc943/1545675993431/White-shouldered-Giant-Ibises.pdf

 

The IUCN - https://www.iucnredlist.org/species/22697536/134200680

 

Sound Recording. Xeno-Canto. Eang Samnang, XC655004. http://www.xeno-canto.org/655004 

Sound Recording. Xeno-Canto. Patrik Åberg, XC124353. http://www.xeno-canto.org/124353 

 

“Ten-year species action plan for the Giant Ibis (Thaumatibis gigantea) in Cambodia 2015-2025.” Loveridge, Robin & Srun, Ty. (2015). – https://www.researchgate.net/publication/309309015_Ten-year_species_action_plan_for_the_Giant_Ibis_Thaumatibis_gigantea_in_Cambodia_2015-2025 

 

World Wildlife Federation – https://wwf.panda.org/es/?209835/New-endangered-giant-ibis-found-in-Cambodia 

 

Wikipedia – https://en.wikipedia.org/wiki/Giant_ibis

Music 27:00

Pledge 33:06

I honor the lifeforce of the Giant Ibis. I will commit its name to my record. I am grateful to have shared time on our planet with this being. I lament the ways in which I and my species have harmed and diminished this species. I grieve.

 

And so, in the name of the Giant Ibis I pledge to reduce my consumption. And my carbon footprint. And curb my wastefulness. I pledge to acknowledge and attempt to address the costs of my actions and inactions. And I pledge to resist the harm of plant and animal kin and their habitat, by individuals, corporations, and governments.

 

I forever pledge my song to the witness and memory of all life, to a broad celebration of biodiversity, and to the total liberation of all beings.