Feather-Eating In Grebes: A 500-Year Conundrum

Jehl, Joseph R.

doi:10.1676/16-196.1

Cited by 10 publications

(5 citation statements)

References 42 publications

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“…However, pellets typically consist of hard‐to‐digest material, such as bones, hair, and feathers, and such traces are not clearly present in this small, dark mass. It is possible that the pellet consists of feathers; grebes intentionally ingest feathers to improve digestive efficiency, later egesting these feathers as part of a bolus also containing undigestible remains (Jehl, 2017). Given what remains of fossil feathers is typically only the preserved melanosomes, preservation of feathers compacted into a pellet may appear as only a dark residue of fossilized melanosomes.…”

Section: Resultsmentioning

confidence: 99%

Avian skulls represent a diverse ornithuromorph fauna from the Lower Cretaceous Xiagou Formation, Gansu Province, China

O’Connor

Stidham

Harris

et al. 2022

J of Sytematics Evolution

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We describe six specimens consisting of cranial remains and associated partial presacral axial series belonging to ornithuromorph birds from the Changma locality of the Lower Cretacous Xiagou Formation of northwestern Gansu Province, China. Comparison among specimens is limited by the paucity of overlapping elements, their differing exposed views, and, in some specimens, poor preservation. Despite this, three separate taxa are represented, evidenced by differences in their dentary dentitions: one specimen is edentulous, another has sharp, closely spaced, relatively high‐crowned and peg‐like teeth, and a third preserves blunt, relatively low‐crowned teeth placed in a communal groove, a morphology previously reported among adult birds only in Hesperornithiformes. We propose that the high‐crowned specimen may be referred to Gansus yumenensis based on shared similarities with the closely related Iteravis huchzermeyeri, including a very similar dentition and an edentulous premaxilla with elongate, unfused frontal processes and no palatal processes. The two other specimens are considered new taxa, for which we erect the names Meemannavis ductrix gen. et sp. nov. and Brevidentavis zhangi gen. et sp. nov. These new specimens confirm that the Changma locality is dominated by ornithuromorph birds and contribute to a better understanding of this important avifauna. The observed variation in dental morphology hints at trophic diversity like that observed in ornithuromorphs from the penecontemporaneous Jehol Group of northeastern China.

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Section: Resultsmentioning

confidence: 99%

Avian skulls represent a diverse ornithuromorph fauna from the Lower Cretaceous Xiagou Formation, Gansu Province, China

O’Connor

Stidham

Harris

et al. 2022

J of Sytematics Evolution

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“…are known to infect leeches as their second intermediate hosts. Although it is quite feasible that grebes would eat the occasional leech, it seems unlikely that they would ingest enough to accumulate the thousands of metacercariae in the gizzard, especially considering that grebes void at least part of their gizzard contents daily as pellets (Jehl, 2017 ). This leaves the likelihood that the cysts belong to a species of Apatemon , (possibly Apatemon sp., “ jamiesoni ” that occurs in large numbers in bullies Gobiomorphus cotinianus MacDowall).…”

Section: Discussionmentioning

confidence: 99%

Gastrointestinal helminth parasites of the threatened Australasian crested grebe (Podiceps cristatus australis, Gould 1844) in New Zealand, with descriptions of Baruscapillaria kamanae n. sp. (Nematoda: Trichuridae) and Cryptocotyle micromorpha n. sp. (Trematoda: Opisthorchiidae)

Presswell

Bennett

2022

Syst Parasitol

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The Australasian crested grebe Podiceps cristatus australis, Gould 1844 is restricted to Australia and New Zealand, where it is listed as Threatened and Nationally Vulnerable. For the first time in New Zealand, we report on the parasitic helminths infecting three individuals from Lake Wanaka, Otago, using morphological and molecular tools. Seven helminth species were found in the gastrointestinal tract: 2 nematodes (Contracaecum ovale and Baruscapillaria kamanaen. sp.), 4 trematodes (Australapatemon minor, Cryptocotyle micromorphan. sp., Tylodelphys darbyi and Neopetasiger neocomensis), and 1 cestode (Confluaria pseudofurcifera). Except for T. darbyi, all are new records for New Zealand. A change of orthography is proposed for Neopetasiger neocomensis and N. pseudoneocomensis. Cryptocotyle micromorphan. sp. (Opisthorchiidae) is distinguished from similar species by its small size, wholly extracaecal vitellaria and anteriorly looped uterus. Baruscapillaria kamanaen. sp. (Trichuridae) is distinguished from other freshwater species by a combination of vulva and spicule morphology. The helminth parasites found here are mostly the same as those from the grebe in the northern hemisphere, indicating that they have been carried with the host species in its spread to Australasia. However, the parasite fauna may be depauperate due to a diminishing reservoir of intermediate hosts in that geographical migration.

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“…This was proposed to allow bones and other sharp objects to be insulated (Simmons, 1956), protecting the alimentary tract from puncture. However, Jehl (2017) argued that ingested feathers instead function to retain food in the stomach for chemical digestion and filter undigested food from entering the intestine. Feather eating is also known in captive birds, especially parrots and chickens (McKeegan & Savory, 1999), but in this case appears to be a non‐functional behavioural disorder.…”

Section: Feather Functionsmentioning

confidence: 99%

Feather function and the evolution of birds

Terrill

Shultz

2022

Biological Reviews

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The ability of feathers to perform many functions either simultaneously or at different times throughout the year or life of a bird is integral to the evolutionary history of birds. Many studies focus on single functions of feathers, but any given feather performs many functions over its lifetime. These functions necessarily interact with each other throughout the evolution and development of birds, so our knowledge of avian evolution is incomplete without understanding the multifunctionality of feathers, and how different functions may act synergistically or antagonistically during natural selection. Here, we review how feather functions interact with avian evolution, with a focus on recent technological and discoverybased advances. By synthesising research into feather functions over hierarchical scales (pattern, arrangement, macrostructure, microstructure, nanostructure, molecules), we aim to provide a broad context for how the adaptability and multifunctionality of feathers have allowed birds to diversify into an astounding array of environments and life-history strategies. We suggest that future research into avian evolution involving feather function should consider multiple aspects of a feather, including multiple functions, seasonal wear and renewal, and ecological or mechanical interactions. With this more holistic view, processes such as the evolution of avian coloration and flight can be understood in a broader and more nuanced context.

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Feather-Eating In Grebes: A 500-Year Conundrum

Cited by 10 publications

References 42 publications

Avian skulls represent a diverse ornithuromorph fauna from the Lower Cretaceous Xiagou Formation, Gansu Province, China

Avian skulls represent a diverse ornithuromorph fauna from the Lower Cretaceous Xiagou Formation, Gansu Province, China

Gastrointestinal helminth parasites of the threatened Australasian crested grebe (Podiceps cristatus australis, Gould 1844) in New Zealand, with descriptions of Baruscapillaria kamanae n. sp. (Nematoda: Trichuridae) and Cryptocotyle micromorpha n. sp. (Trematoda: Opisthorchiidae)

Feather function and the evolution of birds

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