18 de mayo de 2024

Body composition of juveniles of the eastern white-bearded wildebeest (Connochaetes albojubatus) near Nairobi, Kenya




Body mass 111 kg

Carcass mass = 54.2%

Skin = 7.9%

Feet = 2.9%

Head = 7.3%

Brain = 0.267%

Eyeballs = 0.0438%

Tongue = 0.23%

Masseter = 0.133%

Heart = 0.726%

Lungs = 1.55%

Spleen = 0.35%

Liver = 1.28%

Kidneys = 0.265%

Rumen = 1.67%

Reticulum = 0.275%

Omasum = 0.43%

Abomasum = 0.34%

Total intestines (full?) = 4.83%

Total stomach = 2.72%

Except for brain and skin, the above values resemble those of the ostrich more than those of adults of Alcelaphus cokii, of similar body mass, resemble the ostrich. The ostrich is constrained in some ways like a juvenile ruminant, with big organs and feet (suggesting emphasis on mobility and foraging and rapid metabolism).

Publicado el mayo 18, 2024 03:19 TARDE por milewski milewski | 6 comentarios | Deja un comentario

Some ungulates have bigger eyeballs than others

Relative to body mass, the following have exceptionally large eyeballs:

This is remarkable for various reasons, e.g.

The Maasai giraffe (https://craftfineart.com/sink-c-jeffrey-maasai-giraffe-ido-129120) also has notably large eyeballs for an ungulate, relative to its body mass.

Wild, non-bovin bovids in Africa have larger eyeballs than do like-size cervids on other continents, as is apparent if one merely looks at photos of the animals (https://www.istockphoto.com/photo/a-close-up-profile-portrait-of-a-female-black-faced-impala-gm1218530588-356087085).

However, the trend is borne out by the regression below for the red deer, and by information on Axis axis (https://creatures-of-the-world.fandom.com/wiki/Chital_Deer?file=Ftd-axis-deer.jpg) and Odocoileus virginianus (https://www.alamy.com/profile-of-a-white-tailed-deer-image209768621.html and https://pixels.com/featured/whitetail-doe-face-brook-burling.html).

The proportionately small eyeballs of the red deer (https://www.masterfile.com/image/en/700-06758256/portrait-of-a-red-deer-cervus-elaphus-female-bavaria-germany) seem at odds with its unusual orbital prominence, and the fully lateral placement of the eyes (https://stock.adobe.com/images/a-close-up-head-and-shoulder-portrait-of-a-female-red-deer-staring-forward/298586849).

Bovin bovids (https://en.wikipedia.org/wiki/Bovini) have eyeballs smaller than expected for their body mass.

This is particularly noteworthy in the African savanna buffalo (https://www.masterfile.com/image/en/841-06446194/cape-buffalo-syncerus-caffer-with-redbilled and https://www.dreamstime.com/profile-portrait-cape-buffalo-wild-side-view-profile-portrait-cape-buffalo-african-wilderness-image277091409), which scores 20% below par, in contrast to the 50% above par scored by the common eland.

Perhaps the most puzzling of all these findings - despite being well-known - is how small the eyeballs are in the hook-lipped rhino (https://upload.wikimedia.org/wikipedia/commons/6/69/Black_Rhino_at_Working_with_Wildlife.jpg).

It is evident that domestication has led to a diminution of the eyeballs in both

In the latter case, the resulting eyeballs (https://www.dreamstime.com/profile-view-animal-portrait-big-domestic-pig-big-domestic-pig-profile-view-image186895256) are even smaller, proportionately, than in rhinos, because even wild suids have small eyes.

In the case of the common warthog, there is the same incongruity as in the red deer: the orbits are noticeably prominent (in this case dorsally, not laterally, https://www.dreamstime.com/head-profile-common-warthog-phacochoerus-africanus-image153887595). However, the eyeballs remain small relative to like-size, coexisting bovids (https://www.dreamstime.com/stock-photography-warthog-image2002732).

The following are the quotients, calculated relative to adult body mass from the interspecific regression, in decreasing order of eyeball mass:

Equus caballus +0.5
Taurotragus oryx +0.5
tragelaphin bovids (small sample of two spp., Crile and Quiring 1940) +0.4
Giraffa tippelskirchi +0.3
Equus quagga +0.25
Aepyceros melampus +0.2
alcelaphin bovids including Connochaetes +0.1
reduncin bovids +0.1
gazelles (Eudorcas thomsonii and Nanger granti) +0.05
Oryx (small sample, Crile and Quiring 1940) 0
neotragin bovids (small sample, Crile and Quiring 1940) 0
Bos taurus -0.05
Syncerus caffer (small sample, Crile and Quiring 1940) -0.2
Cervus elaphus -0.2
Ovis aries -0.2
elephantids -0.3
Phacochoerus africanus -0.5
Diceros bicornis -0.7
Sus scrofa domesticus -0.9


Publicado el mayo 18, 2024 12:40 MAÑANA por milewski milewski | 0 comentarios | Deja un comentario

17 de mayo de 2024

The ostrich as a quasi-ungulate, part 1

The ostrich does not coexist with any monogastric or ruminant species sharing both its body size and its avoidance of a grass diet.

The diet of the ostrich is qualitatively and even quantitatively similar to those of ruminant concentrate-selectors or 'mixed feeder', particularly coexisting gazelles smaller than the ostrich.

The ostrich seems tolerant of silica-rich forbs, contributing to its ecological separation from ungulates.

The ostrich, in its most extreme habitat, coexists with

  • a grazer larger-bodied than itself, viz. Oryx,
  • a grazer/browser smaller-bodied than itself, viz. Gazella.

Both are adapted to reduced intakes (ruminants) and have advantages of foraging at night.

The grazer accepts up to 40% of the diet as browse, fruits, tubers, and forbs, largely for their water-content. The grazer/browser accepts up to 30% of the diet as the same, though smaller, items, and probably some insects too. Neither eats faeces, nor relies on forbs. Both avoid competition with the ostrich partly by foraging at times when atmospheric moisture condenses, and partly by resorting to landforms avoided by the ostrich.

The grazer is the arid-zone counterpart of semi-arid-adapted alcelaphins, which are more specialised grazers, partly because they can drink (and ultimately mesic hippltragin and large reduncins).

The grazer/browser is the arid-adapted counterpart of small-bodied reduncins and tragelaphins, because neither grass nor browse will support a specialist.

Where two spp. of gazelles coexist with the ostrich, the smaller-bodied one eats more grass (cannot reach much browse, and does not depend on forbs), and the larger-bodied eats more browse because it can reach it. They have about the same dietary quality, in terms of protein.

The more browsers extend into the arid zone, the ganglier they become (giraffes, gerenuk, dama gazelle). Nanger granti is the last outpost of a 'normal browser' towards dry country, after all the tragelaphins have expired.

Spatial separation and limited bulk demands/food quality are two sides of the same strategy. If a species can survive the shortage in the desert, then the quality is likely to be fair. If physical separation is hard, and coexistence is inevitable, then the animal must eat as little as possible in order to avoid competition and to exploit microspatial separation based on advantages in economy of movement. I.e. do what browsers do, but on the ground floor = go 'down and out'. If the animal can afford to pick and choose, then it can wait to find items others have found too awkward to eat.

The ostrich does not enhance mobility by reducing ingesta mass in body, but rather maximises this (compensating with e.g. reduction of toes) and draws indirect benefits from digestive power and hence reduced bulk demands, allowing it to move instead of having to eat so frequenty.

Publicado el mayo 17, 2024 06:32 MAÑANA por milewski milewski | 13 comentarios | Deja un comentario

16 de mayo de 2024

Summary of life-history strategies of African bovids (Bovidae)

Most bovids have gestation periods of

  • about 6 months in the smallest-bodied, fastest-growing spp.,
  • about 7 months (relatively small-bodied spp.),
  • about 9 months (relatively large-bodied spp.),
  • 11 months (Syncerus caffer).

Compare the above values with

  • 5 months in Phacochoerus,
  • 7 months in Hippopotamus,
  • 12 months in Equus quagga,

Most bovids have birth-weight percentages of about 5-10%, exceeding 10% in the most precocial spp. The values for Phacochoerus and Hippopotamus are less than this.

Most bovids reach sexual maturity at

  • about 9 months in relatively small-bodied spp.,
  • 1.2-1.4 years in Connochaetes,
  • 2.5 years in large-bodied, slow-growing spp.,
  • 2.75 years in Syncerus caffer.

Compare the above values with

  • 1.5 years in Equus quagga and (check) Phacochoerus,
  • 4 years in Hippopotamus (exceeding the value for Giraffa)
Publicado el mayo 16, 2024 10:20 TARDE por milewski milewski | 0 comentarios | Deja un comentario

How do the niches differ between the ostrich (Struthio camelus) and a coexisting ungulate, Grant's gazelle (Nanger granti)? part 2

Crude protein estimation for Grant's gazelle
Values are weighted means (% crude protein X % of diet*).
Harpachne schimperi https://www.inaturalist.org/taxa/343051-Harpachne-schimperi leaves 1220 (8.6%); stems 22.4 (4.2%)
Cynodon dactylon/nlemfuensis leaves 152.7 (4.2%); stems 16.8 (2.3%)
'Harpachne lin' leaves 130.6 (9.2%); stems 12.2 (2.3%)
Microchloa kunthii https://www.inaturalist.org/taxa/165373-Microchloa-kunthii leaves 54.7 (3.85%); stems 12.2 (2.3%)
Themeda triandra leaves 4.2 (0.4%); stems 0.3 (0.1%)
Sida sp. indet. https://www.inaturalist.org/observations?place_id=56881&subview=map&taxon_id=54996&view=species leaves and stems 210.0 (14.0%)
Unidentified leaves 5.5 (0.4%
); stems 28.6 (5.4%)
Indigofera leaves and stems 340.2 (14.0%
Solanum leaves 123.2 (6.2%) fruits 26.2 (1.54%)
Leguminous seeds and pods 127.5 (5.1%)
Asteraceae indet. 76.5 (5.1%
Balanites aegyptiaca 72.8 (2.6%*)

Total = 1583
Mean = 15.83% crude protein

Publicado el mayo 16, 2024 05:52 TARDE por milewski milewski | 0 comentarios | Deja un comentario

Ostrich cf warthog

Sexless means for body composition of ostrich cf warthog. All values of mass are percentages of body mass.

Body mass 111.0 kg 70.7 kg

Dressing percentage 54.2% 52.3%

Head 0.615% 11.605%

Feet 3.8% 1.51%

Hide 5.713% 5.291%

Heart 0.865% 0.379%

Lungs and trachea 1.855% 0.869%

Spleen 0.053% 0.200%

Liver 1.478% 1.353%

Total gastrointestinal tract, empty 8.027% 3.40%

Stomach, empty 3.31% 0.534%

Stomach contents 3.06% 1.007%

Small intestine, empty 1.351% 0.776%

Small intestine contents 1.613% 1.617%

Small intestine length 8.82 m 10.207 m

Caecum length (paired in ostrich) 0.95 m 0.214 m

Large intestine including caecum, empty 2.86% 2.00%

Large intestine including caecum, contents 9.78%(needs checking) 10.3%

Large intestine including caecum, length 11.8 m 7.215 m

Total ingesta 13.94% 12.94%

Publicado el mayo 16, 2024 05:15 TARDE por milewski milewski | 3 comentarios | Deja un comentario

How do the niches differ between the ostrich (Struthio camelus) and a coexisting ungulate, Grant's gazelle (Nanger granti)? part 1


Ecological separation between the wild ostrich (Struthio camelus) and gazelles is unclear.

The ostrich is sympatric with gazelles, with a similar diet and fermentative digestion of fibre.

There is no obvious separation by foraging height, since the ostrich forages mainly near ground-level, and several gazelles reach to the height of the bird by bipedal standing.

The ostrich and gazelles are both tolerant of dry heat, with no obvious difference in their penetration of arid zones.

The ostrich is diurnal. Gazelles can potentially forage at night. However, this would not per se prevent competition for the same plants.

However, the ostrich exceeds gazelles in stride-length and body size. Furthermore, the bird breeds more synchronously than at least those gazelle spp. coexisting with it in mesic areas.

Offspring of the ostrich are, from the egg stage onwards, left to progressively fewer adult custodians as they develop towards adulthood.

Hence the movements of most adults are possibly not constrained by care of offspring as in gazelles - particularly in view of the potential masculine territoriality of gazelles.

Based on its body size alone, the ostrich should have an advantage of greater daily mobility and greater potential for nomadic movements than those of gazelles. The bird potentially walks faster and more efficiently, with a greater ability to forgo shade and to commute long distances to drink.

The economy of leg-length and bipedality would enhance this. However, such locomotory specialisation would also potentially bring costs of instability relative to quadrupeds.

Hence, the ostrich would be expected to avoid unstable substrates, such as deep, loose sand and rocky slopes.

Together, these considerations would suggest that the ostrich is better-suited than gazelles for exploiting the ephemeral appearance of food in remote areas on flat, firm ground.

Publicado el mayo 16, 2024 04:20 TARDE por milewski milewski | 2 comentarios | Deja un comentario

15 de mayo de 2024

Diet of the Maasai ostrich (Struthio camelus massaicus) on the Athi-Kapiti plains, Kenya

Struthio camelus massaicus (https://www.inaturalist.org/observations?taxon_id=322201)


Wildlife Ranching and Research, which was later renamed Swara Plains Conservancy (https://www.perplexity.ai/search/What-is-the-UV5KdNn1SCaEOGLoyrCChw), and was recently incorporated into Nairobi National Park.

Time of fieldwork:

Intermittently during 1987-1989


The following are the genera recorded eaten by the Maasai ostrich, either found in adult stomachs (n = 10 individuals) or observed in 17 foraging bouts by one habituated adult individual.

Percentages refer to mass eaten in the first instance, and incidence in stomachs in the second instance.

Asterisks (*) indicate those families also recorded to be eaten frequently during the direct observations.

All families were recorded in the diet of this population of the Maasai ostrich in both the dry and rainy seasons, except Balanitaceae (eaten mainly in the dry season), and Cyperaceae and Acanthaceae (eaten mainly in the green season).

  • *Asteraceae (Aspilia, Galinsoga, Tagetes, Bidens) 23.0% (0-90); 60%
  • *Malvaceae (Hibiscus, Pavonia, Melhania,?Abutilon) 17.6% (5-40); 90%
  • *Poaceae (Sporobolus, Cynodon, Eragrostis) 15.7% (0-75); 80%
  • *Commelinaceae (Commelina) 14.5% (0.1-60); 100%
  • *Fabaceae (Indigofera, Crotalaria, Dolichos, Trifolium) 6.8% (0-30); 20%
  • Solanaceae (Solanum) 5.2% (0-20); 50%
  • Balanitaceae (Balanites) 5.2% (0.1-22); 90%
  • Mimosaceae (??Vachellia) 2.7% (0-20); 50%
  • Asphodelaceae and Asparagaceae (Aloe, ?Albuca) 1.8% (0-6); 40%
  • Euphorbiaceae (Euphorbia) <0.5% (0-2); 30%
  • Cucurbitaceae <0.1% (0-0.5); 10%
  • Cyperaceae <0.1% (0-0.1); 10%
  • Lamiaceae (?Plectranthus, ?Ocimum) <0.1% (0-0.1); -
  • Tiliaceae (Grewia) <0.1% (0-0.2); 10%
  • Convolvulaceae (Ipomoea) <0.1% (0-0.1); -
  • Acanthaceae (Justicia, Crossandra) <0.1% (0-0.1); -
  • Polygonaceae (Oxygonum) -
  • Amaranthaceae (Achyranthes) -
  • unidentified 6.8% (0-25); 100%

Aspilia mossambicensis:

Galinsoga parviflora:

Tagetes minuta:

Bidens pilosa:

Hibiscus flavifolius:









Balanites glabra:












Silica content in diet of ostrich

As at 1 May 1989: at least one-third of the non-grass genera in the diet are rich in silica.

Rich in silica:
Aspilia, Justicia, Crossandra, Commelina, Pavonia, Cucumis, all grasses, Salvadora

Moderately rich in silica:
Galinsoga, Ipomoea, Hibiscus, Heliotropium

Poor in silica:
Balanites, Euphorbia, Solanum, Vachellia, Monechma

Unknown as yet:
Melhania, Indigofera

Publicado el mayo 15, 2024 10:49 TARDE por milewski milewski | 3 comentarios | Deja un comentario

Food values of sundry plants in East Africa

Most recent: Calculation of silica content in diet of ostrich



https://pubmed.ncbi.nlm.nih.gov/16578767/ and https://europepmc.org/article/med/16578767









In each case, the first value is % of diet, and the second value is silica %

Asteraceae 15.6% 8.0% 124.8
Malvaceae 18.6% 4.0% 74.4
Commelinaceae 12.8% 8.5% 108.8
Fabaceae 8.1% 0.7% 5.67
Balanitaceae 5.4% 0.2% 1.08
Solanaceae 5.4% 0.1% 0.54
Acanthaceae 0.8% 7.0% 5.6
Convolvulaceae trace 3.0% 0.03
Poaceae 18.0% 4.8% 86.4
seed capsules 4.0% 0.3% 1.2
inflorescences 3.5% 0.2% 0.7
pods of legumes 2.0% 0.3% 0.6
succulents 1.5% 0.4% 0.6
fib st 0.8% 0.2% 0.16
faeces 1.0% 4.0% 4
fleshy fruits 0.5% 0.2% 0.1
invertebrates trace 0% 0
other 2.0% 1.0% 2.0

Total = 416.68
Mean = 4.2% silica content

Solanum fruits rival grass leaves in crude fibre: 30% (Field 1975)

Ratios of condensed tannins to crude protein:
Vachellja drepanolobium 5.9/21=0.28
Vachellia seyal 1.7/15.5=0.11
Vachellia xanthophloea (Wrangham and Waterman 1981 and Altman et al.) about 0.09
Aspilia mossambicensis 0.7/15= 0.046
Hibiscus flavifolius 0.8/15= 0.053
So, ratios of condensed tannins to crude protein in Vachellia spp. (about 0.1-0.3) seem double those of staples in the diet of the ostrich, viz. Aspilia and Hibiscus.

Look up Dougall and Sheldrick (1964), who record Melhania ovata crude protein in stem and leaf 11.8%

Wilson and Bredon (1963) record crude protein of Pavonia patens as 19.1%

Ratios of silica to crude fibre
Dougall (1963a):
grasses 4.11/30.28=0.135
herbaceous legumes 1.18/21.9=0.054
leguminous browse (woody plants) 0.59/30.32=0.019
non-leguminous browse 1.6/28.78=0.056
Bredon and Wilson:
whole plants of grasses in Zone I, Karamoja:
Mean = 0.25

Dougall (1963a) found that, in general,

  • grasses have ratios of silica to crude fibre 7-fold those of leguminous browse plants such as Vachellia,
  • herbaceous legumes showed intermediate ratios, and
  • ratios in leguminous browse are less than half those in herbaceous legumes.

From Wilson and Bredon (1963), New nutrient analyses to feed into my calculations:
Commelina cp 7.1-14.4% cf 19.8-28.3% si 5.3-15.3% with mean 9.65%, making a new overall mean of 8.5%
Justicia exigua si 5.99% (!!!)
Heliotropium rather calcium-rich si 5.3% (!)
Ipomoea spp. si range 0.74-5.13 mean 2.96
Crossandra cp 10.9% cf 24.3% si 11.5% (!!!)
Hibiscus 8-14.7%
Monechma cp 18.2% cf 26.5% si 1.6%
Pavonia cp 19.1% cf 16.3% si 11.9% (!!!)


There is a definite link between woodiness and tannin content. Acacias are particularly rich in tannins, the leaves varying with age in tannin content.


  • are bitter-tasting, rather than spicy
  • contain flavonoids
  • are poor in tannins
  • contain compounds of nitrogen; in some cases fairly toxic with alkaloids (not as much as in Solanum), including iridoids, quiniline alkaloids, and quinaziline alkaloids

Capparidaceae (Boscia and Capparis are well-known, Maerua is not)

  • usually spicy (amides or glucosinolates)
  • Boscia known to have glucosinolates (mustard)
  • some (probably excluding Maerua) have cyanogenic glycosides
  • Maerua contains small pepperidine alkaloids, as in Salvadora; tastes spicy like pepper; Maerua and Salvadora probably contain less tannin than do acacias
  • condensed tannin content unknown


  • contain calcium oxalate and potassium salts, but not potassium oxalate
  • silica-rich (evergreen rough leaves in Dobera)
  • Salvadora persica contains small nitrogenous molecules and is stringy, and perhaps antibacterial substances (mildly antiseptic)

Grass leaves do sometimes contain oxalates (typically associated with succulents). Birds may be preadapted to deal with oxalates.

Euphorbia (including forbs)

  • nasty latex
  • diterpenes in foliage and fruit
  • heterochroma

Celtis leaves silica-rich, according to Waterman


  • seed largely non-toxic, containing oil and simple, common triterpenes
  • fleshy fruit-pulp is very palatable
  • probably poor in tannins


  • peculiar chemically
  • leaves of Tribulus relatively innocuous
  • seeds contain alkaloids


  • well-known for bitter principles
  • few alkaloids, as in Cucurbitaceae generally
  • cucurbitacins
  • not phenolic
  • triterpenes (containing no nitrogen, which is true also for diterpenes)

Achyranthes, Achyropsis

  • seem fairly innocuous
  • poorly-known

Boraginaceae, particularly Heliotropium

  • tend to be rather toxic
  • alkaloids of quinilidine type, as in Senecio
  • no tannins

Echium and Echinops

  • various defences, including small alkaloids

Similarities among Salvadora, Maerua, and Acanthaceae:

  • small, non-aromatic nitrogenous compounds (e.g. azomin, carpane)
  • 2-methylpepperidines, which taste peppery but lack antimicrobial activity
Publicado el mayo 15, 2024 09:37 MAÑANA por milewski milewski | 3 comentarios | Deja un comentario

14 de mayo de 2024

A comparison of organ sizes between the common warthog (Phacochoerus africanus) and the domestic pig (Sus scrofa)


The common warthog (Phacochoerus africanus, https://www.inaturalist.org/taxa/42122-Phacochoerus-africanus) is extreme, among Suidae (https://en.wikipedia.org/wiki/Suidae), for its adaptation to African savannas.

This is based on a combination of

  • specialisation on a staple diet of grass,
  • dependence on burrows for refuge and shelter, and
  • diurnal, not nocturnal, activity.

The most obvious morphological adaptation in the common warthog is in dentition (https://www.instagram.com/p/y7u1rDsXp6/ and https://www.vin.com/apputil/content/defaultadv1.aspx?pId=26439&catId=159991&id=10047368&ind=32&objTypeID=17#:~:text=The%20premolars%20and%20molars%20are,tubules%20may%20have%20single%20roots.).

The teeth are extremely modified for grinding fibrous and gritty items, mainly the rhizomes of grasses.

I was, therefore, curious to see how the internal organs of the common warthog differ in proportional size from those of the domestic pig (Sus scrofa, https://www.inaturalist.org/observations?taxon_id=324492).



Common warthog: data collected in Uganda by H P Ledger and N S Smith (authors of https://www.jstor.org/stable/3798800 and https://www.semanticscholar.org/paper/The-Carcass-and-Body-Composition-of-the-Uganda-Kob-Ledger-Smith/c891d40fecc1cb23ead94a137421e929870c1df3 and https://kalrorepository.kalro.org/items/eab259a5-ccd3-44ab-8e84-872dc179970d) for

  • n = 10 adult females, and
  • n = 11 adult males.

Domestic pig: various references (all referring to sexually mature subadults of both sexes that have not yet attained full body mass), including https://www.scielo.cl/scielo.php?pid=S0718-16202009000200002&script=sci_arttext and https://www.jstage.jst.go.jp/article/jvms/60/5/60_5_545/_pdf and https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9863662/ and https://www.perplexity.ai/search/Give-lengths-of-7EadhvLkRVyTwb1r31OJPg.

RESULTS (all values are means)

Body masses:
Common warthog 71 kg, domestic pig 112 kg.

This indicates a two-fold difference in full maturity, probably owing partly to the mass of adipose tissues in the domestic pig.

The contents of the large intestine, including the caecum, are much more massive, relative to body mass, in the common warthog (10.3%) than in the domestic pig (2.2%).

The small intestine is remarkably short, both absolutely and relatively to body mass, in the common warthog (7.2 m) compared to the domestic pig (17.0 m).

The following are absolutely similar between the two spp.:

  • mass of empty stomach,
  • length of large intestine (5.1 m for common warthog, 4.8 m for domestic pig),
  • mass of heart, and
  • mass of spleen.

The following are similar in mass, relative to body mass:

  • empty stomach (common warthog 0.53% of body mass, domestic pig 0.48%),
  • empty small intestine (common warthog 0.78%, domestic pig 0.93%)
  • liver (common warthog 1.35%, domestic pig 1.07%).

The following organs are somewhat more massive, relative to body mass, in the common warthog than in the domestic pig:

  • empty large intestine, including caecum (common warthog 2.0%, domestic pig 1.15%)
  • mass of heart (common warthog 0.38%, domestic pig 0.26%),
  • mass of lungs (common warthog 0.87% including trachea, domestic pig 0.24%)
  • mass of spleen (common warthog 0.2%, domestic pig 0.12%).

The following are nebulously/slightly more massive in the common warthog than in the domestic pig, relative to body mass:

  • stomach (0.53% cf 0.48%), and
  • liver (1.35% cf 1.07%).


The comparison is complicated by the differences

  • in mature in body masses between the two spp., and
  • the different ontogenetic stages of the individuals sampled for each species.

Slight differences in the relative sizes of certain organs may possibly be explained by the domestic pig having been selectively bred for fattiness.

However, the most striking difference is that the large intestine (including the caecum) of the common warthog is clearly more filled - absolutely as well as relatively - than that of the domestic pig. Consistent with this is that the small intestine of the common warthog is shorter than that of the domestic pig.

These salient differences may be explained by the fibrous diet of mainly grass of the common warthog, compared to the omnivory of the domestic pig.

The main differences between the common warthog and the domestic pig relate to gastrointestinal fermentation (in the hindgut). Any differences relating to cursoriality (heart and lungs) are minor.

Perhaps the crucial difference in this whole comparison is that - in conjunction with modification of the dentition - the contents of the large intestine are far more massive than those of the domestic pig.

This reflects the grazing specialisation of the common warthog, and its dependence on volatile fatty acids generated by microbes in the colon and caecum. In this way, the common warthog is somewhat convergent with Equidae.

Note: The small intestine of the common warthog happens to be absolutely similar in length to that of the coexisting ostrich (Struthio camelus). I plan to Post on this topic soon...

Publicado el mayo 14, 2024 02:42 TARDE por milewski milewski | 1 comentario | Deja un comentario