Archivos de diario de julio 2024

03 de julio de 2024

The real - and disappointing - nature of the red wolf ('Canis rufus')

@ptexis @matthewinabinett @tonyrebelo @jeremygilmore @dinofelis @beartracker @paradoxornithidae @adamwelz @karoopixie @leytonjfreid @thebeachcomber @maxallen

There are several 'dogs not barking' in the real nature of the red wolf (Canis rufus, https://en.wikipedia.org/wiki/Red_wolf) of southeastern North America.

And these oversights offer insights into the values of nature conservation, the scientific method and - indeed - human psychology.

Everyone knows that

However, what is not appreciated - because it is too dispiriting to contemplate - is that the red wolf is probably also profoundly hybridised with the domestic dog (Canis familiaris).

If it were accepted that the real nature of the red wolf is a three-way hybrid, among domestic dog, coyote, and wolf, then it might seem unjustifiable to spend so much time, energy, and money on the conservation of what cannot be argued to be a wild animal.

However, such acceptance has yet to arrive. And this 'blind spot' has amounted to cognitive dissonance, and a failure of scientific objectivity.

Dear readers, please consider:
How could the domestic dog not have been involved, in an important way, in the ancestry of the red wolf?

The answer is that it must be assumed to have been involved. There are two planks in my rationale, the first based on a logic of consistency, and the second pointing out a 'sin of omission'.

Firstly:

Taxonomists seem unanimous in the view that the wolf is the main ancestor of the domestic dog. This implies an acceptance - that should likewise be unanimous - that the introduction of the domestic dog to North America led to hybridisation with the wolf.

Because this introduction occurred at the end of the Pleistocene (https://www.perplexity.ai/search/when-was-the-domestic-dog-intr-KGnFbfn4TT6KfeOsMkAZuQ),

All-dark individuals, in populations of the wolf in both North America and Eurasia, particularly signify a history of hybridisation with the domestic dog (https://en.wikipedia.org/wiki/Black_wolf and https://www.indiatimes.com/news/india/black-wolf-photographed-for-the-first-time-in-india-here-is-why-it-is-concerning-631944.html). Such individuals have occurred likewise in the red wolf, indicating that it, too, is introgressed.

Secondly:

The various genetic analyses of the red wolf have been 'deafeningly silent' on the question of how important the domestic dog has been in the ancestry of 'Canis rufus' (https://www.perplexity.ai/search/various-studies-have-been-publ-fqScDp3oQ0O7JkXBrzGlag).

This indicates cognitive dissonance (https://en.wikipedia.org/wiki/Cognitive_dissonance), because

  • everyone has assumed that the domestic dog is, in a sense, a non-wild form of mainly the wolf, and yet
  • nobody has assumed that the red wolf may, by the same token, be mainly a feral form of the domestic dog.

Now, there is an additional aspect, which would be a 'nail in the coffin' for any notion that the red wolf deserves to be conserved as a wild animal.

This is that

Several aspects of the colouration of the red wolf indicate affinity with 'Canis rubronegrus', rather than either the wolf or the coyote. These include

I suggest, therefore, that

Either way, attempts to bring the red wolf back from the brink may have been an expensive mistake.

It is one thing to accept that, in a genus as phylogenetically fluid as Canis, it is somewhat arbitrary whether any population qualifies as a particular species (as opposed to a hybrid).

However, it is another thing to pretend that a 'coywolf' is worth conserving, in a region of North America where one of the components, namely the coyote, was not even indigenous in the first place.

It is another thing again to 'shoehorn', into the concept of a valid species, an entity that is two-steps downgraded (latrans X lupus X lupus-familiaris) from an original species.

And it would be yet another grade of delusion, beyond the above three grades, to ignore that the hybridisation involved not two, but three original wild spp. (latrans X lupus X rubronegrus-familiaris).

Is the reality not that, in a region altered anthropogenically for ten millennia, and altered by Europeans for 500 years (https://www.perplexity.ai/search/when-did-europeans-first-settl-bxkgLugnQbGc.NulizD5lQ), any species of truly wild Canis is long-lost?

And is the likelihood not that, in continuing to avoid coming to terms with this loss, we conservationists are undermining our own effectiveness?

Publicado el julio 3, 2024 06:55 TARDE por milewski milewski | 13 comentarios | Deja un comentario

04 de julio de 2024

A puzzling lack of honeydew-producing hemipteran insects in the Cape Floristic Region of South Africa

@tonyrebelo @jeremygilmore @ludwig_muller @rjpretor @psyllidhipster @wongun @fabienpiednoir @bnormark @nomolosx @vynbos @peterslingsby @erincpow

Honeydew (https://en.wikipedia.org/wiki/Honeydew_(secretion) and https://www.sciencedirect.com/science/article/abs/pii/B9780123741448001314) is produced by various families of sap-sucking hemipterans in the suborders

The main sternorrhynchan families involved are

(For auchenorrhynchan families see https://www.inaturalist.org/posts/96522-a-puzzling-lack-of-honeydew-producing-hemipteran-insects-in-the-cape-floristic-region-of-south-africa#activity_comment_ad4868eb-6860-4458-b914-3a0659762ec5.)

Honeydew-producing hemipterans are common and diverse in several ecosystems that are

  • dominated by evergreen, woody plants,
  • nutrient-poor (particularly w.r.t. phosphorus and zinc), and
  • prone to wildfire.

The following ecosystems are particularly relevant.

Boreal forest (https://en.wikipedia.org/wiki/Taiga):

The incidence of sap-sucking hemipterans is summarised in https://www.perplexity.ai/search/which-are-the-main-sap-sucking-EM7jj6ifR_y2Oe2cmqAO_Q.

Eucalypt-dominated vegetation in Australia:

https://www.perplexity.ai/search/which-are-the-main-honeydew-pr-QS6kGDpTTjGYw1.ScOdFew

Honeydew is so common in eucalypt-dominated vegetation that honeyeaters (Meliphagidae) often eat this substance in place of nectar (https://www.publish.csiro.au/mu/mu9800213).

Kwongan in Australia:

https://en.wikipedia.org/wiki/Kwongan

https://www.perplexity.ai/search/which-are-the-main-honeydew-pr-Iwn26FAGRvC_JBgVwgLhKQ

At least one family of honeydew-producing hemipterans, viz. Pseudococcidae, is noted for its diversity in the floristically-rich southwestern region of Western Australia (https://www.perplexity.ai/search/which-honeydew-producing-sap-s-4PdFXzbnSziooSPIbxUcYw and https://www.inaturalist.org/posts/96522-a-puzzling-lack-of-honeydew-producing-hemipteran-insects-in-the-cape-floristic-region-of-south-africa#activity_comment_4fdf2d80-eeb1-404c-9aac-4f7225c93fe9).

Cerrado in South America:

https://en.wikipedia.org/wiki/Cerrado

https://www.perplexity.ai/search/which-hemipteran-insects-indig-TiqquV83QTSTUcxhCozDGA

Now, the fynbos biome of South Africa is nutrient-poor and fire-prone (https://en.wikipedia.org/wiki/Fynbos and https://www.sciencedirect.com/science/article/pii/S0254629914002117).

Therefore, we might expect fynbos - and the Cape Floristic Region (https://en.wikipedia.org/wiki/Cape_Floristic_Region) in general - to feature honeydew-producing hemipterans.

However, I have found hardly any information on this in the literature (https://www.perplexity.ai/search/anoplolepis-tends-sap-sucking-tebUgY.xQMuD36uISyJYNg and https://www.perplexity.ai/search/in-southern-africa-which-indig-yHiltTzwTESZjCLocBN0aA and https://www.perplexity.ai/search/in-southern-africa-which-are-t-Yajw5J0hT0GAFWFTNu8Zug and https://www.perplexity.ai/search/is-there-any-literature-on-hon-BNXvvEnVQAS_Gi41Ja.GyA).

Nectariniidae (https://www.perplexity.ai/search/is-any-member-of-nectariniidae-AArpb.xdSre4mi7wy.IwnA) and Promeropidae (https://www.perplexity.ai/search/has-promerops-ever-been-record-WC3kBuvWSGCnV5Nz5jg6hw), common in fynbos, have not been recorded eating honeydew. In this way, they differ from their approximate ecological counterparts, viz. Meliphagidae, in Australia.

It may be relevant that European heathland, superficially similar to ericoid fynbos (https://en.wikipedia.org/wiki/Ericoid), also seems poorly-documented for honeydew-producing hemipterans (https://www.perplexity.ai/search/which-are-the-main-honeydew-pr-N0CYxtJtRMqg9Z9zB2sjRw).

This leaves us with the following question:

Is the dearth of information on honeydew-producing hemipterans in fynbos because of a gap in coverage, or does it reflect a real poverty, indicating some basic and poorly-understood aspect of the functions of the ecosystem?

SUPPLEMENTARY INFORMATION

The following are notes in the biogeography of various clades of honeydew-producing hemipterans.

https://www.perplexity.ai/search/discuss-the-global-biogeograph-J68xinpFToaQOqoSGYJK_g

In the Northern Hemisphere, Aphididae are a major family producing honeydew. In Australia, indigenous Aphididae are ecologically unimportant (https://academic.oup.com/aesa/article/96/2/107/27979). Here,their place is taken by Psyllidae and Pseudococcidae.

In New Zealand, the main indigenous sternorrhynchans that produce honeydew are Margarodidae, Coccidae, and Aphididae.

https://www.perplexity.ai/search/do-psyllid-sternorrhynchans-pr-F84f5VCFQMOSXWN8vNd2Vg

https://www.perplexity.ai/search/pseudococcidae-tend-to-such-sa-Q5pvd3jQQaubsyLEv64Y5Q

https://www.perplexity.ai/search/do-indigenous-psyllids-in-aust-0vrzrZ2mS4SBzhuTNoK2oA

https://www.perplexity.ai/search/which-indigenous-plants-in-new-cRhfuyerSRa6F1RBp9SbKg

https://www.perplexity.ai/search/in-new-zealand-various-indigen-TRnETOxnTbS0xeooSKV8Qg

https://www.perplexity.ai/search/worldwide-which-genera-of-cocc-C7SioRtSQluLN9q0ZM2ISw

https://www.perplexity.ai/search/is-any-member-of-adelgidae-sap-D55Q1W02RoyWA5fzqQjU8Q

https://hal.science/hal-00890589/document

Publicado el julio 4, 2024 09:54 MAÑANA por milewski milewski | 21 comentarios | Deja un comentario

07 de julio de 2024

The ecological and biogeographical significance of Prodotiscus regulus, an anthropogenic addition to the avifauna of Cape Town, South Africa

@tonyrebelo @ludwig_muller @jeremygilmore @vynbos @lukedowney @carasylvia @moxcalvitiumtorgos @rion_c @johnnybirder @theoutdoorman102 @surfinbird @justinponder2505 @simontonge @nwatinyoka @richardgill @adamwelz @boerseun86 @luke_goddard @zroskoph @kristaoswald @gareth_bain @wikus_burger @wingate @joelradue @colin25 @lindeq @the_bush_fundi @gigilaidler @lindalakeside @manatok @christiaan_viljoen @ekmes @ianrijsdijk @markheystek

Prodotiscus regulus (https://www.inaturalist.org/taxa/17591-Prodotiscus-regulus) is

The aim of this Post is to explain how P. regulus has come to be the only species of bird in the Cape Floristic Region (https://en.wikipedia.org/wiki/Cape_Floristic_Region) that specialises dietarily on the exudates of sap-sucking hemipteran insects (https://tcimag.tcia.org/training/sap-sucking-insects-how-they-feed-and-the-damage-they-cause/).

Like all members of its family (https://www.sciencedirect.com/science/article/abs/pii/S1095643302001307#:~:text=Birds%20ate%20significantly%20more%20new,transit%20time%20of%20256%20min. and https://pubmed.ncbi.nlm.nih.gov/12160878/), P. regulus can digest wax (https://en.wikipedia.org/wiki/Wax), as a major source of metabolic energy.

This is remarkable, because wax is

Before European arrival, there was no niche for P. regulus in the southwestern part of South Africa.

This is mainly because

Exudates of sap-sucking hemipterans are mainly of two kinds, viz.

Europeans introduced several spp. of Acacia (https://en.wikipedia.org/wiki/Acacia) from Australia to the Cape Floristic Region.

These shrubs and trees have proven to be so ecologically vigorous in their new environment that they are regarded as invasive (https://www.cabidigitallibrary.org/doi/10.1079/9781800622197.0026).

Also introduced - albeit mainly inadvertently - from various parts of the world were several hemipterans capable of sucking the sap of these acacias (https://www.perplexity.ai/search/australian-spp-of-acacia-have-5WdSTOFwQHK06p4MSWQYiw and https://en.wikipedia.org/wiki/Icerya_purchasi).

Now, for the first time in and near Cape Town (https://en.wikipedia.org/wiki/Cape_Town), there was a plentiful source of sap-sucking hemipterans and their exudates, as potential food for arboreal birds indigenous to South Africa.

In the case of honeydew, the main indigenous bird that seems to have benefited is Zosterops, a genus observed elsewhere in Africa to forage side-by-side with P. regulus (Friedmann 1955, https://repository.si.edu/handle/10088/10101 and https://scholar.google.com/citations?user=62DqSSUAAAAJ&hl=en).

Zosterops (https://www.inaturalist.org/observations?place_id=6986&taxon_id=17439&view=species) is a small-bodied passerine with the odd combination of a short, thin beak and a brush-tipped tongue. This allows it to lap up the newly-provided honeydew, in addition to its original staple diet of fleshy fruit-pulp (and -juice) and insects (https://www.researchgate.net/publication/249439178_Summer_and_winter_diet_of_the_Cape_white-eye_Zosterops_pallidus_in_South_African_grassland#:~:text=...-,The%20Cape%20white%2Deye%20is%20described%20as%20a%20generalist%20feeder,their%20diet%20(Kopij%202004)%20.).

However, this hardly changed Zosterops biogeographically, because it had been present in the Cape Floristic Region in the first place.

In the case of the waxy exudates, the only indigenous birds that might benefit were Indicatoridae.

As many as three spp. of Indicator may have been indigenous to the Cape Floristic Region, viz.

However, this genus is adapted to take wax from the nests of Hymenoptera, not from the exudates of hemipterans. This preference may be explained partly by the fact that Indicator is larger-bodied than Prodotiscus (https://en.wikipedia.org/wiki/Honeyguide).

Instead, what seems to have happened is that a small-bodied species, viz. P. regulus, entered the Cape Floristic Region for the first time during the twentieth century. This spontaneous recruitment filled the newly-provided niche.

There was no competition between P. regulus and Zosterops, because

  • the former is hardly able to ingest honeydew, and
  • the latter is unable to digest wax.

Honeydew is not utilised by Indicatoridae, despite

The inutility of honeydew for Indicatoridae, including P. regulus, seems to be because they

What has arisen is something biogeographically remarkable, and overlooked by naturalists despite the avifauna of Cape Town, and the Cape Floristic Region, being intensively studied.

This is that

Publicado el julio 7, 2024 03:45 MAÑANA por milewski milewski | 9 comentarios | Deja un comentario

09 de julio de 2024

Is the Australian mole (Notoryctes) a supermole?

Also please see https://www.youtube.com/watch?v=tyWF1G8_ExQ&t=7s

The marsupial mole (Notoryctes, https://en.wikipedia.org/wiki/Marsupial_mole and https://www.abc.net.au/news/2023-06-17/elusive-marsupial-mole-spotted-uluru-swims-in-sand/102482890 and https://books.google.com.au/books?hl=en&lr=&id=5IqhZoTEF10C&oi=fnd&pg=PA464&dq=Marsupial+mole&ots=KQKu9dlYtl&sig=6N4ZqycOmL5In2yGuKzJVJ7tIF8&redir_esc=y#v=onepage&q=Marsupial%20mole&f=false) superficially resembles placental moles, despite being unrelated to them.

This is one of the most striking examples known of evolutionary convergence (https://en.wikipedia.org/wiki/Convergent_evolution).

However, the marsupial mole does not merely combine the presence of a pouch with the disappearance of eyes and ears.

As research gradually uncovers the details about the only Australian mole, what is emerging is that this is more than a lookalike.

The marsupial mole may indeed be the quintessential mole. It not only matches, but possibly surpasses, the adaptive extremes shown by subterranean mammals on other continents.

The marsupial mole has a large, bare pad on the head (https://www.bbc.com/news/world-australia-68720246). This has not been studied, but appears to be a blunt instrument of subterranean locomotion.

Unlike other moles, the marsupial mole has fused vertebrae in the neck, which presumably allows great pressure to be placed on the head as a ramrod.

Typical moles (Talpidae, https://en.wikipedia.org/wiki/Talpidae) lack a burrowing organ on the head, instead having pointed muzzles as soft as those of shrews.

Golden moles (Chrysochloridae, https://en.wikipedia.org/wiki/Golden_mole), the moles of Africa, have a tough nose used as a wedge (https://afrotheria.net/golden-moles/photos.php). However, the bare pad is far too small to extend to the forehead.

If typical moles and golden moles are not as extremely adapted to butting through the earth as is the marsupial mole, this may be because they repeatedly commute along tunnels once they have constructed them.

The marsupial mole appears to have no open tunnels, instead forcing its way afresh through every centimetre of earth in the course of its locomotion (https://www.publish.csiro.au/am/AM13015).

In this sense, the marsupial mole may be the ultimate subterranean mammal.

A failure to construct tunnels explains why, unlike other moles, the marsupial mole does not make molehills.

The Namib golden mole (Eremitalpa, https://en.wikipedia.org/wiki/Grant%27s_golden_mole) also lacks molehills. However, it differs from the marsupial mole by depending partly on swimming through the relatively loose sand at the surface of dunes. They maintain their body temperatures, remain active and warm even under the snows of winter, and reproduce relatively rapidly.

The forefoot of the marsupial mole is extreme, since the claws form a vertical spade (https://www.abc.net.au/news/2024-04-07/-northern-marsupial-mole-kakarratul-sighted-/103662744).

Typical moles have different forefeet, essentially broad paws projecting sideways as if from the neck (https://www.sci.news/biology/european-moles-sand-08805.html and https://www.parchilazio.it/cammino_naturale_dei_parchi-schede-7288-animalisulcammino_la_talpa_europea and https://nature.guide/card.aspx?lang=en&id=579), and used for raking relatively crumbly soil sideways.

Whereas the claws of typical moles move beside the body, those of the marsupial mole cleave the sand downwards, in front of the body.

Golden moles have pick-like claws on digits number 2 and 3 of the forefoot, held horizontal instead of vertical.

The marsupial mole has similar claws in digits 2 and 3. However, it has an additional, particularly large claw on digit 4, which forms the main blade of the articulated spade.

Typical moles lack external ears, but retain internal ear bones capable of hearing low-pitched vibrations underground.

The marsupial mole is unique among moles, because its entire ear is degenerate. The extremely small size of its internal ear bones suggest that the marsupial mole is nearly deaf as well as blind (https://www.mdpi.com/2073-4425/14/11/2018 and https://www.pnas.org/doi/abs/10.1073/pnas.94.25.13754).

This contrasts with the golden moles, in some of which the size of the ear bones exceeds that of surface-dwelling mammals, proportional to body size.

The tail of the marsupial mole is odd, inviting further study. Its appearance suggests that the tail may be used as a prop, allowing extra pressure to be placed on the head and claws. If so, the use of the tail in digging is unprecedented among subterranean mammals. No-one has yet a found a way to observe the marsupial mole in action underground.

The marsupial mole differs in habitat from other moles. It is widespread in, and apparently restricted to, hummock grassland (https://www.anbg.gov.au/photo/vegetation/hummock-grasslands.html and https://www.publish.csiro.au/am/AM00115).

This is a peculiar type of 'desert' restricted to Australia, sandy and dry but vegetated (https://www.inaturalist.org/posts/58175-the-australian-empty-quarter-epitome-of-a-nutrient-desert#).

Failure of Europeans and domestic animals to exploit hummock grassland owes more to this land's extreme nutrient-poverty than its aridity (https://www.inaturalist.org/posts/58175-the-australian-empty-quarter-epitome-of-a-nutrient-desert).

This semi-desert is even less fertile than the Sahara, so that 20% of Australia remains deserted to this day, despite the availability of groundwater in boreholes.

The main cover consists of grasses (Triodia, https://en.wikipedia.org/wiki/Triodia_scariosa) more spiny, unpalatable, and flammable than any common grass on other continents.

Although sand is extensive on the other southern continents, no mole lives in vegetated sand under dry conditions far inland.

Typical moles are widespread in the Northern Hemisphere (https://people.wku.edu/charles.smith/faunmaps/Talpidae.htm). However, they depend on the organic, loamy soils of deciduous woodlands.

Golden moles in Africa extend to sandy substrates in coastal areas. However, they are absent from the only habitats comparable to that of the marsupial mole: the Kalahari in southern Africa (https://en.wikipedia.org/wiki/Kalahari_Desert), and sandy parts of the Sahel at the edge if the Sahara (https://en.wikipedia.org/wiki/Sahel).

There are no moles today in central and South America, although fossil moles related to armadillos have been excavated. The most mole-like species alive now is the lesser fairy armadillo (Chlamyphorus truncatus, https://www.inaturalist.org/taxa/47097-Chlamyphorus-truncatus), restricted to a small area of sandy soil in semi-arid Argentina (https://upload.wikimedia.org/wikipedia/commons/2/29/Lesser_Fairy_Armadillo_area.png).

What little is known of the diet of the marsupial mole suggests an unusual reliance on insect larvae (https://zslpublications.onlinelibrary.wiley.com/doi/abs/10.1111/j.1469-7998.2011.00889.x). I suspect that the tropical species of marsupial mole (Notoryctes caurinus) may depend partly on the brood (eggs, larvae, pupae) of ants, which it raids by burrowing from one subterranean ant nest to another.

By comparison:

Subterranean mammals have to devote most of their food energy to the strenuous work of burrowing. However, they save energy when resting, because the underground environment has a comfortable temperature and a poor supply of oxygen.

In addition, protection from predators means that subterranean mammals do not need to devote much energy to reproduction.

The resting metabolism of golden moles and armadillos is even slower than that of most marsupials. However, further research may show that the reproduction of the marsupial mole is particularly slow.

If so, it is possible that the marsupial mole devotes less of its energy to offspring, and more of its energy to locomotion, than any other subterranean mammal. Typical moles are different, because they have a rich supply of earthworms in ventilated tunnels.

The marsupial mole stretches our concept of the genetic plasticity of marsupials. It may also be a 'supermole' in stretching adaptive limits beyond those of placental moles. The broad hard organs of its head and forefeet, and to a lesser degree hindfeet and tail, equip it to burrow afresh to each meal, despite the poor food to be found in a habitat lacking both nutrients and water.

Genetic constraints and geographical isolation therefore fail to explain the absence of other body forms (equivalent to bears, pigs, primates, otters, cats, and ruminants) in the indigenous fauna of Australia.

In particular, the lack of mole-rats in Australasia is unlikely to be an accident of history. All other continents (including central and South America) have rodents resembling gophers, derived from a total of eight families which have independently undergone reduction of eyes, ears, tails, and resting metabolic rates (https://www.jstor.org/stable/2096793).

However, the supply of edible tubers appears to be smaller in hummock grassland than in the Kalahari. Possibly, mole-rats failed to evolve in Australia because of a lack of suitable tubers as food.

Publicado el julio 9, 2024 08:36 MAÑANA por milewski milewski | 17 comentarios | Deja un comentario

A new term for an important biological phenomenon: introducing 'secromorphosis' as categorically distinct from metamorphosis

@oecophylla @lehelind

Before reading this Post, please watch https://www.youtube.com/watch?v=3EVLJChVV48.

Everyone knows that

However, there is another process whereby the bodies of arthropods are radically modified. This deserves a term of its own: secromorphosis.

[As a necessary digression, please note a terminological quirk. The biological adjective derived from the noun 'metamorphosis' is 'metabolous', not 'metamorphic'. Likewise, those derived from holometamorphosis and hemimetamorphosis are respectively holometabolous and hemimetabolous. In accordance, the adjective derived from my new term - albeit unsatisfactory owing to some ambiguity with metabolism - would be secrobolous, not secromorphic.]

In metamorphosis,

By contrast, in secromorphosis, the transformation of the body - which can be extreme (https://lostcoastoutpost.com/nature/5938/ and https://australian.museum/learn/animals/insects/giant-female-scale-insects-and-bird-of-paradise-flies/ and https://www.ecoorganicgarden.com.au/problem-solver/how-to-control-lerps/ and https://www.dpi.nsw.gov.au/agriculture/horticulture/citrus/content/insects-diseases-disorders-and-biosecurity/insect-pest-factsheets/long-tailed-mealy-bug#:~:text=Description&text=Adults%20are%203%E2%80%934%20mm,a%202%E2%80%933%20week%20period. and https://www.projectnoah.org/spottings/135616016 and https://www.projectnoah.org/spottings/21883009 and https://upload.wikimedia.org/wikipedia/commons/a/af/Ceroplastes_cirripediformis.jpg and https://upload.wikimedia.org/wikipedia/commons/3/30/Red_lerps_austrochardia_acaciae.jpg) - is achieved by means of secretion.

https://www.treehugger.com/the-planthopper-nymphs-dazzling-style-of-protection-4868356

The body-parts secreted - '3-D printed', as it were, by glands - consist mainly of various organic compounds (https://www.perplexity.ai/search/what-is-the-overall-term-for-m-vzBxp5QiQsiuxJqs.GQVnQ), including both

These secreted structures, which can be substantial relative to body size, are non-living, even though they form part of a living body.

It is true that important components - particularly the exoskeleton and wing-membranes - of the body in metabolous arthropods consist of dead tissue. However, there is a categorical distinction between once-living (i.e. metabolising, containing DNA, and undergoing cell-division), now-dead materials on one hand, and materials that have never been alive on the other.

The relevant body-parts of secromorphic insects, particularly the waxy filaments, shields, and lattices secreted by sap-sucking sternorrhynchan hemipterans (https://en.wikipedia.org/wiki/Sternorrhyncha), fall into the latter category.

Everyone knows that the bodies of arthropods contain non-living components, particularly exoskeletons made of chitin (in some cases reinforced by calcium carbonate).

However, all chitinous body-parts are derived from cell-walls. In other words, they originate as living tissues that have then died and become indurated.

The crucial distinction is that the components produced in secromorphosis are not aptly described as dead. This is because - like secretions as a category - they were not metabolically active in the first place.

Within Hemiptera, the trend is for an inverse correlation between chitinousness and waxiness. Heteroptera rely on chitin, whereas Sternorrhyncha tend to have minimal exoskeletons, relying instead on wax. Achenorrhyncha are intermediate in this respect.

As far as I know,

  • all secrobolous insects are also hemimetabolous, i.e. they show hemimetamorphosis in the form of an ontogenetic series of nymphs culminating in an adult, and
  • most or all secrobolous insects fall within Hemiptera (https://en.wikipedia.org/wiki/Hemiptera).

It follows that most or all secrobolous insects are sap-suckers, foraging mainly on the fluid contents of phloem (https://en.wikipedia.org/wiki/Phloem).

This leads to a strange realisation: that hemipterans manifest two aspects of a rapid throughput of carbon and hydrogen, and to some extent oxygen.

Sap-sucking hemipterans take in much superfluous sugar as they filter dilute fluids for their content of nitrogen and mineral nutrients. As part of this process, they exude the energy-content of most of this sugar, whether as

There is a kind of congruence in the fact that sap-sucking hemipterans

  • take in large quantities of energy superfluous to metabolism, and
  • subsequently exude (3-D print, https://en.wikipedia.org/wiki/3D_printing) the energy-containing substances, in modified form, for various purposes.

In the case of most secrobolous hemipterans (belonging to a bewilderingly large number of families in two suborders and many superfamilies):
sugar in, wax out.

And wax can be so much more durable/imperishable than sugars - indeed, almost as durable as chitin in the case of small insects - that it can effectively constitute a large proportion of the body (albeit extraneous to the tissues, both living and dead).

In the past, most insects have been categorised as either holometabolous or hemimetabolous. With the realisation that many sternorrhynchan and some auchenorrhynchan hemipterans are secrobolous, how should woolly aphids, lerp psyllids, wax scalebugs, etc., be best categorised?

Relevant to this question is the observation that the waxy secretions are best-developed in nymphs in some clades of hemipterans, vs in adults in other clades. In some families, even the eggs are invested in waxy filaments (https://www.perplexity.ai/search/in-which-sternorrhynchan-and-a-SD3Y5dGdRjOM_qDIWNoKZw).

In extreme cases, an adult the size of a small fly (https://upload.wikimedia.org/wikipedia/commons/8/89/Bird_of_Paradise_Fly.jpg) may possess a waxy 'tail', consisting of filaments up to 7.5 cm long (https://www.inaturalist.org/taxa/706751-Callipappus-australis and https://www.perplexity.ai/search/which-sternorrhynchan-hemipter-b8qjNcwDQvOh4qos8rQxSQ).

Given that the secretions correspond incongruently to growth-stages, across the various clades of hemipterans, I would argue that the categorisation of certain taxa as secrobolous is more relevant/informative than their categorisation as hemimetabolous.

Here is a question corollary to this topic:
Does any insect secrete chitin, which is a polysaccharide, viz. a polymer of sugar (https://www.perplexity.ai/search/is-any-arthropod-known-to-secr-xA81XDKuT4ykAEVrVpQxaA)?

SUPPLEMENTARY DEFINITIONS AND CLARIFICATIONS

https://www.perplexity.ai/search/some-waxes-qualify-as-hydrocar-mDycdLR.SEau1cXA_07e4A

https://www.perplexity.ai/search/does-the-term-imago-apply-to-h-2UJbwMNjTySOK7itutyHFg

https://en.wikipedia.org/wiki/Imago

https://en.wikipedia.org/wiki/Instar

https://www.perplexity.ai/search/consider-the-wings-of-a-butter-VMmn0357Ts6wZVsfsOwK6g

https://www.perplexity.ai/search/keratin-is-a-protein-is-chitin-GdtZaMicQTiuWVYVQ1Q1NA

https://www.perplexity.ai/search/many-hemiptera-exude-waxy-stru-miLLSSHESEyi0fyKlhdskQ

https://www.perplexity.ai/search/do-any-crustaceans-undergo-met-G2jx7A7NSd2f4DavQcp6RA

https://www.perplexity.ai/search/is-starch-a-polysaccharide-Tw0HHpHHTFiADMI7PBn74A

https://www.perplexity.ai/search/do-both-larvae-and-nymphs-occu-LY4JgZMATj6vjnJqKaXWag

https://www.perplexity.ai/search/in-hemiptera-is-honeydew-produ-9mwXoi_VT8W9FuJaSF0H6w

https://www.perplexity.ai/search/certain-cercopoidea-construct-I6gW8WPIS_arjvVb8gwCHA

https://www.perplexity.ai/search/nymphs-of-eurybrachidae-posses-TWU6FqsVSd2dx2qRdJXefA

https://biodiversity.org.au/afd/taxa/COCCOIDEA

https://www.perplexity.ai/search/are-any-spp-of-coccidae-indige-BrvR.aZcRPetA.mQvFYZYA

https://www.perplexity.ai/search/do-membracidae-produce-a-honey-9oSjg0FvTdenhOFXOlmqIw

Publicado el julio 9, 2024 09:23 TARDE por milewski milewski | 15 comentarios | Deja un comentario

12 de julio de 2024

Colouration of Gazella pelzelni

I have adopted Gazella pelzelni as a standard, for my studies of adaptive colouration in Gazella and Eudorcas.

METHODS

I disregard all hues, focussing only on pale/dark differentiations.

I estimate tone (from pale to dark) on a scale of 1-10. 1= white, 10= black, and thus 5= medium 'grey'.

All numbers in this Post refer to this tonal scale.

'dark' flank-band up to 7

'pale' flank-band about 3.5

dorsal panel 4 up to 5

ischial stripe (vertical) 5

neck about 4

ventral haunch about 4

outer surface of lower foreleg 4
posterior surface of lower foreleg 2
outer surface of lower hindleg 3.5-4
outer surface of upper foreleg at least 5

shoulder about 5

malar stripe up to 8

chin 1

pale facial stripe, medial to eye 1
pale facial stripe, on side of rostrum 2-3

forehead up to 6

cheek about 3

nasal about 4

tail 9

root of tail 7

Dark rostral spot minimal in adult male, present in adult female

https://www.biolib.cz/en/image/id355000/

https://www.leszoosdanslemonde.com

Publicado el julio 12, 2024 09:50 TARDE por milewski milewski | 1 comentario | Deja un comentario

13 de julio de 2024

17 de julio de 2024

Why is there no such thing as a migratory carnivore?

Publicado el julio 17, 2024 01:46 MAÑANA por milewski milewski | 0 comentarios | Deja un comentario

Is the common hippopotamus (Hippopotamus amphibius) analogous with orangutans (Pongo spp.) in sexual bimaturism? part 1

@markdeeble

(Dear Naturalists, before you read this Post, please realise that - contrary to the impression given in the literature - the following is the 'real' sexual dimorphism:
adult female https://www.inaturalist.org/observations/130503280
fully mature male https://www.inaturalist.org/observations/131393008
together https://www.gettyimages.com.au/detail/news-photo/two-los-angeles-zoo-hippopotamuses-were-transported-tuesday-news-photo/563551061?adppopup=true and https://www.inaturalist.org/observations/182685912 and https://www.gettyimages.com.au/detail/photo/hippopotamus-pair-eating-grass-in-national-safari-royalty-free-image/521352284?phrase=hippo+zoo&adppopup=true and https://www.alamy.com/stock-photo-hippopotamus-at-haller-park-in-mombasa-kenya-22825689.html?imageid=EF0770FF-1288-4768-BB13-927BA0955796&p=2963&pn=1&searchId=5b66b8a6ffa55eec2d24512dc0c4aaa7&searchtype=0 and at minutes 4:00 and 5:00 in https://www.google.com.au/search?sca_esv=ea2cb3181ae7dcdc&sxsrf=ADLYWIKrH74FcLWCSbPkFH_MN-SOiTgFYA:1724375529805&q=Hippo+zoo+berlin&tbm=vid&source=lnms&fbs=AEQNm0BKxFXqFZETuC92mLOmXO9xJMdcEc6vsS8xotR_o6JIE4V6fjYfCiBijvGcXvcw0A1foGVwwGEV12VfBpqJrQOcY1lJEcwoWHBLO3iBa7iZ5QeKaux7sBp-0kIsG2kUeAyUyzSAO-CZcgzBYoFkfzufWRMKGShC9yzL_fiVgQjXh-cDB0Dw_GCPhaIOVi8Sfx8gJtP8O5qwqhDugIYu7nYGZD8J6w&sa=X&ved=2ahUKEwi_hKe394mIAxVNSGcHHbYHEDIQ0pQJegQIDhAB&biw=1004&bih=537&dpr=2.7#fpstate=ive&vld=cid:afd86476,vid:mj62wbabXhQ,st:0).

INTRODUCTION

The common hippopotamus (Hippopotamus amphibius) presents a sociosexual paradox, particularly w.r.t. sexual dimorphism (https://en.wikipedia.org/wiki/Sexual_dimorphism).

This is because it combines extreme polygyny (https://www.merriam-webster.com/dictionary/polygyny) with what seem to be only small differences in body size and shape between females and males.

In general among large mammals, the more polygynous the species, the more sexually dimorphic it tends to be (https://www.perplexity.ai/search/among-large-mammals-which-are-P0S8kU_wSxq3fN_jn2MA9A and https://onlinelibrary.wiley.com/doi/pdf/10.1002/ece3.6246 and https://onlinelibrary.wiley.com/doi/pdfdirect/10.1111/j.0014-3820.2002.tb01438.x and https://www.evolutionary-ecology.com/abstracts/v01/1019.html and https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7297761/).

However, sexual dimorphism in the common hippopotamus seems so limited that it is often difficult to tell the sexes apart (https://core.ac.uk/reader/511307320 and https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8492169/ and https://research.bangor.ac.uk/portal/en/theses/sexual-dimorphism-in-the-common-hippopotamus(755f4355-916f-4340-be69-2a0283ea0037).html and https://royalsocietypublishing.org/doi/10.1098/rsbl.2021.0368 and https://core.ac.uk/reader/511307320 and https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8492169/
and https://www.proquest.com/openview/bf7fe20014d547603c96a18e52506e58/1?pq-origsite=gscholar&cbl=44156 and https://www.youtube.com/watch?v=ct910mx2c8w and https://research.bangor.ac.uk/portal/files/34590613/Sandler_Mres_2020Sandler_MRes_2020_1.pdf and https://www.inaturalist.org/posts/96927-is-the-common-hippopotamus-hippopotamus-amphibius-analogous-with-orangutans-pongo-spp-in-sexual-bimaturism#activity_comment_6175c422-b596-4675-816f-ae658f17f257).

Furthermore, the incisor and canine teeth, although extremely odd among ungulates, have a similar appearance in the two sexes (https://www.inaturalist.org/posts/96927-is-the-common-hippopotamus-hippopotamus-amphibius-analogous-with-orangutans-pongo-spp-in-sexual-bimaturism#activity_comment_71bbd753-64ad-49d7-aa91-abbf419d0618 and https://www.perplexity.ai/search/describe-the-sexual-dimorphism-l9kejg52TsmP5RjO38mZrA).

Given that the common hippopotamus is polygynous (https://ielc.libguides.com/sdzg/factsheets/hippopotamus/reproduction and https://animaldiversity.org/accounts/Hippopotamus_amphibius/), how can this puzzle be resolved?

SEXUAL DIMORPHISM RELATIVE TO TERRITORIALITY

In the habitat of the common hippopotamus, masculine rivalry in the various large-bodied artiodactyls - all of them polygynous - is based either on

  • non-territoriality, in which mating success of males depends mainly on status conferred by brawn and bone, or
  • territoriality, in which mating success of males depends mainly on status conferred by temporary tenure of foraging grounds attractive to females.

Conforming to the category of non-territoriality are the following examples, both of which show extreme sexual dimorphism:

Conforming to the category of territoriality are alcelaphin bovids (https://en.wikipedia.org/wiki/Alcelaphinae), which show minimal sexual dimorphism (https://www.sciencedirect.com/science/article/abs/pii/016815919190264X and https://zslpublications.onlinelibrary.wiley.com/doi/full/10.1111/jzo.13134 and https://zslpublications.onlinelibrary.wiley.com/doi/full/10.1111/jzo.13134).

The common hippopotamus is territorial in a certain sense, and non-territorial in another.

This is because it differs from alcelaphins and other artiodactyls in that its territoriality is confined to the watery refuges of the species, where there is negligible food. The territories completely exclude the extensive lawns on which the species forages, which are free-for-all.

Therefore:
Whichever way the comparison is made, it is anomalous that the common hippopotamus shows minor sexual dimorphism despite its major polygyny. Past studies of the species have failed to resolve this puzzle.

A NEW PERSPECTIVE ON THE PUZZLE

Other authors may have missed a crucial point, which means that the limited sexual dimorphism in of the common hippopotamus is misleading.

The point is that this species may show a kind of 'arrested/suppressed development' w.r.t. the full potential of secondary sexual features of masculinity.

The common hippopotamus is remarkably long-lived for an artiodactyl (https://www.inaturalist.org/posts/97769-lifespan-relative-to-fecundity-in-suids-suidae-compared-with-bovids-bovidae#activity_comment_fbdd32c5-28a4-4f37-8a58-3ae3f00b2ac4 and https://www.gbif.org/species/113274921#:~:text=The%20genitals%20of%20the%20female,function%20of%20these%20is%20unknown).

Maximum lifespan has been recorded as about 65 years in females, and about 62 years in males (https://www.zoochat.com/community/threads/oldest-common-hippopotamuses-in-captive-care.484137/).

However, most adult males in any population remain sexually subordinate, and this may persist for the whole lifetime.

In the sociosexual system of the common hippopotamus,

  • territory-holders have priority in mating with females, and are presumably the males most attractive to females,
  • a remarkably small percentage of adult males acquire territories, and
  • the territorial tenure of a given male individual can be remarkably protracted, up to several decades, so that many/most other males never get a turn to reproduce.

It is possible that, in the common hippopotamus, success in claiming a territory leads to a change in the hormonal status of the individual male.

This then produces additional growth in the body, particularly the head, and even more particularly the lower jaw and its canine and incisor teeth. These teeth remain similar to those of females in shape, but enlarge, both absolutely and relative to the size of the body.

This additional mass enables the territory-holder to prevail continually over the many would-be rivals.

This system would, metaphorically-speaking, be a case of 'nothing succeeds like success', corresponding approximately to 'sexual bimaturism' (https://en.wikipedia.org/wiki/Sexual_bimaturism).

Renewed post-adult growth would, over several years, produce males obviously different in appearance from most adult males in the population. These individuals, although unlikely to be reflected in the many males sampled in culling programmes such as that studied by Laws in Uganda (https://www.researchgate.net/publication/229967272_Dentition_and_ageing_of_the_hippo), would represent the true degree of sexual dimorphism intrinsic to the common hippopotamus.

Most adult males in any population of the common hippopotamus have body mass only modestly exceeding that of adult females. Once the 'arrestment/suppression' of full masculine development is alleviated by territorial success, body mass may increase to double the average for adult females.

POSSIBLE ANALOGY WITH ORANGUTANS

'Sexual bimaturism' has a precedent in orangutans (Pongo spp., https://www.perplexity.ai/search/orangutans-show-bimaturism-whi-8dKevPaeTGKXmx8Crw90Mw and https://www.cambridge.org/core/books/abs/sexual-selection-in-primates/alternative-male-reproductive-strategies-male-bimaturism-in-orangutans/3BF0810A3FFD8D8930E3670B2AD453A3 and https://www.researchgate.net/publication/284553386_Alternative_male_reproductive_strategies_Male_bimaturism_in_orangutans and https://academic.oup.com/beheco/article/13/5/643/327741?login=false and https://d1wqtxts1xzle7.cloudfront.net/54459928/Marty_et_al-2015-Orangutan_bimaturism-libre.pdf?1505715811=&response-content-disposition=inline%3B+filename%3DEndocrinological_correlates_of_male_bima.pdf&Expires=1722723757&Signature=Bjbdyc1fG37eNCtWdr5o6qy-IgklUJ-TY6DOfsscWfI5Qx65EtR6W41yk3T9khxzoK-y~od1gXLszM7Uy70TYpPSxIcsc5ce0EHNHWZf-KPd9OPa4m9NEHwPXSjtG8yY~iVwvD6daWOczjhOU5fVA0Jc0SX2FVy90vG1KWRruzJyTFKfpuwHWiMZO3HB-6sZsSC3NlwEFusa~Ww0gTJKX3XsxdRveOv0qiIuTOFkHzfSRAIm9kxRm6m-bZVw3SbevS2MzNMbPqOMGR431xscWLU01pNQ5aSCRH8jGoUejkJCPuFyiZxfaHBKUQUkukqWRFhuKB-Z35uC~L3Jb-ujLA__&Key-Pair-Id=APKAJLOHF5GGSLRBV4ZA and https://rucore.libraries.rutgers.edu/rutgers-lib/61912/#:~:text=DescriptionBimaturism%20in%20orangutans%20is,physiological%20status%20regulate%20flange%20development. and https://www.researchgate.net/figure/Sexual-bimaturism-in-orangutans-Flanged-A-and-unflanged-B-male-orangutans-from_fig3_232281829 and https://www.eva.mpg.de/documents/Springer/Banes_Male_BehEcoSoc_2015_2191410.pdf and https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10857694/ and https://scholarscompass.vcu.edu/uresposters/241/ and https://www.sciencedirect.com/science/article/abs/pii/S0047248406001795 and https://onlinelibrary.wiley.com/doi/full/10.1002/ajp.23535).

In this phenomenon, full masculine maturity is 'condition-dependent'. However, condition itself depends on success in rivalry, leading to a kind of positive feedback, mediated hormonally (https://pubmed.ncbi.nlm.nih.gov/26235914/).

Furthermore, there is an analogy between the common hippopotamus and orangutans in that the additional developments in masculine anatomy occur on the head, jowls, and neck.

It is noteworthy that both the common hippopotamus and orangutans are remarkably long-lived.

However, the term 'sexual bimaturism' has been used in an unsatisfactory way in the past, for the following two reasons:

  • Firstly, there has been conflation between the pattern seen in orangutans and that in mammals (possibly including the African bush elephant and gorillas, Gorilla spp.) which simply take a long time to reach full masculine maturity via indeterminate growth. One way to think of the distinction is between 'differentially retarded masculine maturity' and 'delayed masculine maturity'.
  • Secondly, even if strictly defined, bimaturism has been an awkward category, in the sense that it has contained only one genus of mammals, namely Pongo.

With the search-image created in this Post, it may be worth re-examining the sociosexual system of the common eland, which possibly also conforms with bimaturism rather than simply indeterminate growth and delayed masculine development.

ADULT FEMALES

The following show the proportionately small head (particularly the lower jaw) of females throughout life:

https://www.inaturalist.org/observations/185587511

https://www.inaturalist.org/observations/171876695

https://animals.howstuffworks.com/animal-facts/is-hippo-milk-pink.htm

Second photo in https://www.inaturalist.org/observations/197828198

https://www.inaturalist.org/observations/32076998

https://www.inaturalist.org/observations/190127894

https://www.inaturalist.org/observations/218461874

https://www.inaturalist.org/observations/3820827

https://www.inaturalist.org/observations/57170046

https://www.dreamstime.com/generated-image-image316220977

https://en.wikipedia.org/wiki/Hippopotamus#/media/File:Portrait_Hippopotamus_in_the_water.jpg

https://www.inaturalist.org/observations/232962788

https://www.inaturalist.org/observations/227720326

https://www.inaturalist.org/observations/205936385

https://www.inaturalist.org/observations/201224495

https://www.inaturalist.org/observations/197162402

https://www.inaturalist.org/observations/194695310

https://www.inaturalist.org/observations/190764350

https://www.inaturalist.org/observations/190054337

https://www.inaturalist.org/observations/186526305

https://www.inaturalist.org/observations/183622070

https://www.inaturalist.org/observations/183310834

https://www.inaturalist.org/observations/182837999

https://www.istockphoto.com/photo/animal-hippopotamus-mother-baby-wildlife-africa-care-nature-safari-river-gm925368832-253942777?searchscope=image%2Cfilm

https://www.inaturalist.org/observations/172773350

https://www.inaturalist.org/observations/168698847

https://www.inaturalist.org/observations/167197548

https://www.inaturalist.org/observations/161474315

https://www.inaturalist.org/observations/149918549

https://www.inaturalist.org/observations/125411308

https://www.inaturalist.org/observations/91239857

https://www.inaturalist.org/observations/88626882

https://www.inaturalist.org/observations/86568312

https://www.inaturalist.org/observations/69880035

https://www.inaturalist.org/observations/58818629

https://www.inaturalist.org/observations/57079975

https://www.inaturalist.org/observations/51625751

https://www.inaturalist.org/observations/9944882

https://www.inaturalist.org/observations/9400962

https://www.inaturalist.org/observations/8926835

https://www.inaturalist.org/observations/29037

https://www.inaturalist.org/observations/224186883

https://www.inaturalist.org/observations/196988622

https://www.inaturalist.org/observations/117092368

MALES, ADULT BUT WITH HYPOTHETICALLY 'ARRESTED/SUPPRESSED' DEVELOPMENT OF SECONDARY SEXUAL FEATURES

The following show that many of the adult males, although they possess an enlarged head (particularly the lower jaw), are so similar to adult females that they can be confused with adult females:

https://www.istockphoto.com/photo/isolated-hippopotamus-on-white-background-gm528295822-92931099?searchscope=image%2Cfilm

https://www.inaturalist.org/observations/199820452

https://www.inaturalist.org/observations/200792328

https://www.inaturalist.org/observations/61636965

https://www.inaturalist.org/observations/99321313

https://www.inaturalist.org/observations/104349123

https://www.inaturalist.org/observations/9398378

https://depositphotos.com/photo/hippopotamus-hippopotamus-amphibius-grazing-bull-evening-light-bank-chobe-river-381793214.html

https://upload.wikimedia.org/wikipedia/commons/8/84/Hippopotamus_in_Chobe_National_Park_02.jpg

https://www.inaturalist.org/observations/104195832

https://www.gettyimages.com.au/detail/photo/single-hippopotamus-and-zebras-on-the-savannah-royalty-free-image/948895248?phrase=grazing+hippopotamus&adppopup=true

https://www.facebook.com/alexwalkersserian/photos/a.853569811352767/2877290685647326/?type=3

https://www.gettyimages.com.au/detail/photo/hippo-at-wild-walking-on-dirt-road-royalty-free-image/1157831488?phrase=grazing+hippopotamus&adppopup=true

https://www.dreamstime.com/stock-photo-wounded-hippopotamus-roaring-square-photograph-old-bull-large-round-wound-gaping-mouth-glaring-eye-one-image84144073

https://www.istockphoto.com/photo/hippo-displaying-territorial-behavior-mpumalanga-south-africa-gm166553772-23575755

https://upload.wikimedia.org/wikipedia/commons/thumb/b/b3/Hipop%C3%B3tamo_(Hippopotamus_amphibius),parque_nacional_de_Chobe,_Botsuana,_2018-07-28,_DD_82.jpg/640px-Hipop%C3%B3tamo(Hippopotamus_amphibius),_parque_nacional_de_Chobe,_Botsuana,_2018-07-28,_DD_82.jpg

https://www.inaturalist.org/observations/103993366

https://www.inaturalist.org/observations/103148015

https://www.inaturalist.org/observations/44380745

https://www.inaturalist.org/observations/16316895

https://www.inaturalist.org/observations/217026021

https://upload.wikimedia.org/wikipedia/commons/thumb/b/b3/Hipop%C3%B3tamo_(Hippopotamus_amphibius),parque_nacional_de_Chobe,_Botsuana,_2018-07-28,_DD_82.jpg/640px-Hipop%C3%B3tamo(Hippopotamus_amphibius),_parque_nacional_de_Chobe,_Botsuana,_2018-07-28,_DD_82.jpg

https://www.inaturalist.org/observations/227460909

https://www.inaturalist.org/observations/222033303

https://www.inaturalist.org/observations/217475755

https://www.inaturalist.org/observations/216525950

https://www.inaturalist.org/observations/207187846

https://www.inaturalist.org/observations/205639372

https://www.inaturalist.org/observations/204704697

https://www.inaturalist.org/observations/199328894

https://www.inaturalist.org/observations/198598844

https://www.inaturalist.org/observations/196988605

https://www.inaturalist.org/observations/196813314

https://www.inaturalist.org/observations/196137731

https://www.inaturalist.org/observations/195619422

https://www.inaturalist.org/observations/194629109

https://www.inaturalist.org/observations/190190748

https://www.inaturalist.org/observations/134265024

https://www.inaturalist.org/observations/127495774

https://www.inaturalist.org/observations/118180804

https://www.inaturalist.org/observations/186577453

https://www.inaturalist.org/observations/185479171

https://www.inaturalist.org/observations/182083121

https://www.inaturalist.org/observations/179594302

https://www.istockphoto.com/photo/hippopotamus-gm485563607-38094122?searchscope=image%2Cfilm

https://www.inaturalist.org/observations/170846673

https://www.inaturalist.org/observations/169650595

https://www.inaturalist.org/observations/187129711

https://www.inaturalist.org/observations/190190748

FULLY MATURE (PRESUMABLY TERRITORY-HOLDING) MALES

The following show that some males, in the same populations, have the head (particularly the lower jaw) and neck so enlarged that their masculinity is immediately noticeable (I suspect that their body mass is also greatly increased, to about three tonnes in contrast to the approximately 1.5 tonnes of most adults in the population):

https://www.inaturalist.org/observations/198786138

https://www.inaturalist.org/observations/110526650

https://www.inaturalist.org/observations/13772994

https://www.inaturalist.org/observations/110522141

https://www.inaturalist.org/observations/45468532

https://www.inaturalist.org/observations/91794820

https://www.inaturalist.org/observations/85734913

https://www.inaturalist.org/observations/77513963

https://www.inaturalist.org/observations/46601791

https://www.inaturalist.org/observations/70166024

https://www.inaturalist.org/observations/68351235

https://www.inaturalist.org/observations/38631403

https://www.inaturalist.org/observations/32590312

https://www.inaturalist.org/observations/19311900

https://www.inaturalist.org/observations/231595279

https://www.inaturalist.org/observations/197618184

https://www.inaturalist.org/observations/175325962

to be continued in https://www.inaturalist.org/journal/milewski/97918-is-the-common-hippopotamus-hippopotamus-amphibius-analogous-with-orangutans-pongo-spp-in-sexual-bimaturism-part-2#...

Publicado el julio 17, 2024 11:44 TARDE por milewski milewski | 51 comentarios | Deja un comentario

21 de julio de 2024

Are clonal aphids (Aphididae) meta-eusocial?

Everyone knows that certain aphids (Aphididae, https://en.wikipedia.org/wiki/Aphid) reproduce largely by parthenogenetic (= clonal) means (https://en.wikipedia.org/wiki/Parthenogenesis and https://onlinelibrary.wiley.com/doi/pdf/10.1042/BC20070135).

However, what is somewhat unappreciated is the puzzle that this raises.

Most other insects that reproduce parthenogenetically (= clonally), beyond Hemiptera, are eusocial (https://en.wikipedia.org/wiki/Eusociality and https://www.researchgate.net/publication/30947830_The_definition_of_eusociality).

Is it really true that aphids have evolved to be able to reproduce largely parthenogenetically (= largely clonally) despite lacking eusociality?

In this Post, I argue that one way to view aphids is as 'meta-eusocial' insects.

The rational goes as follows.

All of the clonal aphids are dependent on ants (Hymenoptera: Formicidae), in a mutualistic relationship.

This trophobiotic (https://en.wikipedia.org/wiki/Trophobiosis) relationship involves more than mere protection from predators and parasitoids. This is because ants tend/husband aphids in more profound ways, analogous to the relationship between Homo sapiens and livestock (https://www.youtube.com/watch?v=KcPcT7dJ3Hc and https://www.youtube.com/watch?v=BigxxBfjaYc).

Indeed, it might be impossible for aphids to reproduce parthenogenetically without their intimate relationship with ants.

Most of the ants that tend aphids are eusocial, and reproduce parthenogenetically. This is significant, despite the fact that in most cases the individual aphids greatly outnumber the individual ants at any one site.

What this means is that the reproductive modes of aphids reflect the eusociality of the mutualism-partners that are crucial for the ecological success of the aphids.

Aphids can be viewed as meta-eusocial, in the sense that their reproductive mode is congruent with, and an 'extension of', that of the ants.

Publicado el julio 21, 2024 12:42 MAÑANA por milewski milewski | 4 comentarios | Deja un comentario