Diario de milewski

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)

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

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%

INTRODUCTION

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.

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

STUDY AREA AND METHODS

Location:
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

RESULTS

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:
https://www.inaturalist.org/taxa/147342-Aspilia-mossambicensis

Galinsoga parviflora:
https://www.inaturalist.org/taxa/48178-Galinsoga-parviflora

Tagetes minuta:
https://www.inaturalist.org/taxa/79313-Tagetes-minuta

Bidens pilosa:
https://www.inaturalist.org/taxa/50203-Bidens-pilosa

Hibiscus flavifolius:
https://www.inaturalist.org/taxa/343058-Hibiscus-flavifolius

Pavonia:
https://www.inaturalist.org/observations?place_id=10957&subview=map&taxon_id=52356&view=species

Abutilon:
https://www.inaturalist.org/observations?place_id=10957&subview=map&taxon_id=53864

Commelina:
https://www.inaturalist.org/observations?place_id=10957&subview=map&taxon_id=52893

Indigofera:
https://www.inaturalist.org/observations?place_id=10957&subview=map&taxon_id=83365&view=species

Crotalaria:
https://www.inaturalist.org/observations?place_id=10957&subview=map&taxon_id=123472&view=species

Dolichos:
https://www.inaturalist.org/observations?place_id=56881&subview=map&taxon_id=139262&view=species

Trifolium:
https://www.inaturalist.org/taxa/55745-Trifolium-repens

Solanum:
https://www.inaturalist.org/observations/215986766

Balanites glabra:
https://en.wikipedia.org/wiki/Balanites_glabra

Grewia:
https://www.inaturalist.org/observations?place_id=10957&subview=map&taxon_id=68716&view=species

Ipomoea:
https://www.inaturalist.org/observations?place_id=10957&subview=map&taxon_id=52346&view=species

Justicia:
https://www.inaturalist.org/observations?place_id=10957&subview=map&taxon_id=50152

Crossandra:
https://www.inaturalist.org/observations?place_id=10957&subview=map&taxon_id=201316&view=species

Melhania:
https://www.inaturalist.org/observations?place_id=7042&subview=map&taxon_id=185886&view=species

Oxygonum:
https://www.inaturalist.org/observations?place_id=7042&subview=map&taxon_id=553830&view=species

Achyranthes:
https://www.inaturalist.org/observations?place_id=10957&subview=map&taxon_id=142081

Albuca:
https://www.inaturalist.org/observations?place_id=7042&subview=map&taxon_id=119218

Aloe:
https://www.inaturalist.org/observations?place_id=10957&subview=map&taxon_id=71956

Plectranthus:
https://www.inaturalist.org/taxa/430498-Plectranthus-fruticosus

Ocimum:
https://www.inaturalist.org/observations?place_id=10957&subview=map&taxon_id=61399&view=species

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

Most recent: Calculation of silica content in diet of ostrich

See

https://www.jstor.org/stable/1940401

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

https://www.researchgate.net/publication/355163451_Forage_quality_in_tundra_grasslands_under_herbivory_Silicon-based_defences_nutrients_and_their_ratios_in_grasses

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7317429/

https://eprints.nwisrl.ars.usda.gov/id/eprint/510/1/673.pdf

https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2017.00438/full

https://www.researchgate.net/publication/267292612_Silica_as_a_plant_defense_against_herbivorous_insects

https://api.research-repository.uwa.edu.au/ws/portalfiles/portal/106649226/AAM_A_shift_from_phenol_to_silica_based.pdf

https://www.researchgate.net/publication/6432754_Herbivore_specific_induction_of_silica-based_plant_defences

https://esajournals.onlinelibrary.wiley.com/doi/am-pdf/10.1002/ecy.3250

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:
6.29/27.74=0.23
6.48/31.49=0.21
7.33/33.02=0.22
8.75/34.88=0.25
7.77/35.86=0.22
13.66/27.63=0.49
9.19/32=0.29
7.45/34.04=0.22
5.47/34.86=0.16
6.57/30.91=0.21
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% (!!!)

INTRODUCTION

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).

METHODS

Sources:

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%).

DISCUSSION

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...

THE PROBLEM

Various organisms seem unnecessarily extravagant - even wasteful - in their allocation of resources to certain structures and functions of life.

This constitutes a scientific - i.e. biological as opposed to philosophical - puzzle.

By resources, I mean materials, energy, and opportunities in the sense of 'opportunity costs' (https://en.wikipedia.org/wiki/Opportunity_cost).

A classic example is the masculine tail of the Indian peafowl (Pavo cristatus, https://www.inaturalist.org/taxa/1204-Pavo-cristatus, https://archive.nytimes.com/www.nytimes.com/books/98/12/06/specials/cronin-ant.html).

However, an even more puzzling anatomical example is the large antlers (https://en.wikipedia.org/wiki/Antler) of various spp. of Cervidae.

These annually shed-and-regrown bony structures consume orders of magnitude more phosphorus and other nutrients than are devoted to the permanent - and relatively small - head adornments of comparable Bovidae (https://en.wikipedia.org/wiki/Bovidae).

An example in the realm of energetics, rather than anatomy as such, is the stotting gaits (https://en.wikipedia.org/wiki/Stotting) of herbivores such as the Rocky Mountain mule deer (Odocoileus hemionus hemionus, https://www.youtube.com/watch?v=h8DweS5Z684 and https://www.inaturalist.org/observations?taxon_id=143865)

In scientific enquiry and rigorous thinking, it is important to use words as precisely as possible.

For this reason, neither 'extravagant' nor its various synonyms are apt in a purely biological context.

All of them - including 'prodigal' (https://en.wikipedia.org/wiki/Parable_of_the_Prodigal_Son) - have moral overtones (https://www.merriam-webster.com/thesaurus/extravagant).

More particularly, the moral implication of the existing words tends to be one of 'wantonness', or even sinfulness.

A SOLUTION

What is ideally needed is a word combining

• unambiguousness,
• precision in meaning, and
• scientific objectivity.

For the above reasons, I have invented a new term, while taking care to adhere to sound etymological principles.

The word 'prodigal' (https://www.youtube.com/watch?v=Nttqb8GvneU) derives from the Latin adjective 'prodigus', meaning 'lavish'.

This same word-root can easily be rendered to 'prodigous' instead of 'prodigal' (https://www.youtube.com/watch?v=QrmWACALQcU).

The only difference is '-ous' instead of '-al'. Please see https://www.perplexity.ai/search/In-the-English-XWU6c7epTLOzcbiT3IAFNA.

Please note that the word 'prodigious', spelt with an 'i' after a 'soft g', has

• different spelling,
• different pronunciation,
• different meaning (https://www.merriam-webster.com/dictionary/prodigious#:~:text=1,%2C%20quantity%2C%20or%20degree%20%3A%20enormous),
• different word-origin (https://www.etymonline.com/word/prodigious), from the Latin noun meaning 'portent', and
• a particular lack of objectivity (https://dictionary.cambridge.org/dictionary/english/portentous).

I thus introduce to Biology two new words, namely the adjective 'prodigous' (pronounced with a hard 'g'), and its corresponding abstract noun 'prodigousness'.

An example of how to use 'prodigous' is as follows:

"The head adornments of the extinct deer Megaloceros (https://en.wikipedia.org/wiki/Megaloceros) are so prodigous that they may seem to have been maladaptive. However, what are needed are rigorous analyses of costs vs benefits, to reveal the real adaptive values of extreme sexual dimorphism in the context of natural selection in a past environmental regime in the Pleistocene".

https://publikace.nm.cz/file/65e338da90c2c6469589bbae61894ea9/20321/255_294_Rookmaaker.pdf

@tonyrebelo @jeremygilmore @ludwig_muller @variani18 @ptexis @oviscanadensis_connerties @tandala @davidbygott @zarek @maxallen @dinofelis @capracornelius @dejong @beartracker @matthewinabinett @jwidness @aguilita @paradoxornithidae

Everyone knows that the pronghorn (Antilocapra americana) is extremely speedy and enduring when running (https://www.nature.com/articles/353748a0).

Also generally accepted is that this capacity to perform is owing partly to the large heart of the pronghorn relative to body size (https://en.wikipedia.org/wiki/Pronghorn and https://lewis-clark.org/sciences/mammals/pronghorn/ and https://ielc.libguides.com/sdzg/factsheets/pronghorn/characteristics and https://www.facebook.com/migrationinitiative/photos/a.1555355961349673/2764556360429621/?type=3).

No skeptical scientist seems to have questioned the implication of an uniquely large heart in this, the only surviving member on Earth of the family Antilocapridae.

It may therefore surprise readers to hear that the reputation of a massive heart in the pronghorn is exaggerated.

Somewhat like the continually repeated fallacy that reedbucks (Redunca) raise the tail in alarm (https://www.inaturalist.org/posts/39738-contrary-to-field-guide-books-reedbucks-redunca-spp-do-not-flag-the-tail-in-alarm#), this seems to be a case of a tenuous 'fact' being passed unquestioningly from one semi-popular author to another.

It is true - as originally asserted by McKean and Walker half a century ago (1974: (https://www.sciencedirect.com/science/article/abs/pii/0034568774900668) - that the heart of the pronghorn is significantly larger, proportionately, that that of a domestic caprin bovid (Capra hircus).

However, their reported value of 0.95% - referring to the mass of the heart as a percentage of body mass in adults of the pronghorn - turns out to be unexceptional compared with various other ruminants of similar body size.

My collation of the data is as follows, for ruminants of adult body mass 20-80 kg. The order is that of decreasing proportional mass of the heart:

• Rangifer tarandus tarandus (semi-domesticated) 1.0% (Ringberg J M 1981 Body growth and carcass composition of lean reindeer (Rangifer tarandus tarandus L.) from birth to sexual maturity. Can J Zool 59: 1040-1044)
• Dama dama 0.95% (n = 19 female individuals, https://www.mdpi.com/2076-2615/13/6/1082)
• Antilocapra americana 0.95% (https://www.sciencedirect.com/science/article/abs/pii/0034568774900668)
• Eudorcas thomsonii thomsonii 0.94% (my own data, Wildlife Ranching and Research, Athi-Kapiti plains, Kenya)
• Odocoileus virginianus 0.9% (https://pubmed.ncbi.nlm.nih.gov/7380330/)
• Damaliscus pygargus phillipsi 0.845% (n = 8 adolescent individuals, https://www.researchgate.net/profile/Liana-Maree/publication/326460201_Physical_and_chemical_carcass_composition_of_springbok_Antidorcas_marsupialis_blesbok_Damaliscus_dorcas_phillipsi_and_impala_Aepyceros_melampus/links/5b4ec4efa6fdcc8dae27b55c/Physical-and-chemical-carcass-composition-of-springbok-Antidorcas-marsupialis-blesbok-Damaliscus-dorcas-phillipsi-and-impala-Aepyceros-melampus.pdf)
• Pantholops hodgsonii 0.84% (n = 9 adult males, https://avmajournals.avma.org/view/journals/ajvr/73/6/ajvr.73.6.809.xml)
• Aepyceros melampus 0.82% (n = 16 adult females, Hoffman L C, Kritzinger B, and Ferreira A V 2002 The effects of sex and region on the carcass yield and chemical composition of impala (Aepyceros melampus), being Chapter 3, pp.70-89 in Kritzinger B 2002 Meat quality parameters of the impala (Aepyceros melampus) MSc Thesis, University of Stellenbosch)
• Nanger granti granti adult females 0.80% (my own data)
• Litocranius walleri adult males 0.77% (n = 5, N S Smith, Galana Ranch, Kenya, 13-19 February 1964)
• Capricornis crispus adult males 0.75% (n = 34, https://www.jstor.org/stable/3801288?origin=crossref and https://link.springer.com/chapter/10.1007/978-94-011-8030-6_33)
• Antidorcas marsupialis marsupialis 0.71% (n = 8 adult individuals, https://www.researchgate.net/profile/Liana-Maree/publication/326460201_Physical_and_chemical_carcass_composition_of_springbok_Antidorcas_marsupialis_blesbok_Damaliscus_dorcas_phillipsi_and_impala_Aepyceros_melampus/links/5b4ec4efa6fdcc8dae27b55c/Physical-and-chemical-carcass-composition-of-springbok-Antidorcas-marsupialis-blesbok-Damaliscus-dorcas-phillipsi-and-impala-Aepyceros-melampus.pdf)
• Capricornis crispus adult females 0.67% (n = 25, https://www.jstor.org/stable/3801288?origin=crossref and https://link.springer.com/chapter/10.1007/978-94-011-8030-6_33)
• Nanger granti granti adult males 0.65% (my own data)
• Capra hircus 0.50% (https://www.sciencedirect.com/science/article/abs/pii/0034568774900668)
• Ovis aries Tibetan breed 0.48% (https://avmajournals.avma.org/view/journals/ajvr/73/6/ajvr.73.6.809.xml)
• Ovis aries fat-tailed breed in Java 0.42% after adipose tissues subtracted from body mass (Hasanah U et al. 2019 Carcass composition of fat tailed sheep at different slaughter weight, IOP Conference Series: Earth and Environmental Science 260)

Further data for Rangifer tarandus platyrhynchus may possibly be found in Krog J, Wika M, Lund-Larsen T, Nordfjell J, and Myrnes I (1976) Spitzbergen reindeer, Rangifer tarandus playrhynchus Vrolik: Morphology, fat storage and organ weights in the late winter season. Norwegian Journal of Zoology 24: 407-417.

In adults of Homo sapiens, the mass of the adult heart (about 310 grams) is about 0.5% of body mass (https://hypertextbook.com/facts/2006/StephanieGambino.shtml and https://pubmed.ncbi.nlm.nih.gov/22182983/ and https://bionumbers.hms.harvard.edu/bionumber.aspx?id=115099&s=n&v=1 and https://pubmed.ncbi.nlm.nih.gov/26153896/).

For comparison, in adults of thoroughbreds of Equus caballus, the heart is about 0.9% of body mass (see details in comment below).

The heart is hardly more massive, relative to body mass, in domestic caprin bovids (C. hircus and O. aries) than in humans. This is probably the result of an anthropogenic process of diminution, resulting inadvertently from selective breeding in domestication.

This means that the original finding, viz. that the heart of the pronghorn is far more massive than that of C. hircus, was misleading in comparing a fully wild species with a fully domesticated species.

In this Post, I have corrected the unintended exaggeration that has followed this initial mistake.

However, my collation raises a new puzzle, as follows.

Gazelles are remarkably heterogeneous, among genera and - in the case of Nanger granti granti - between the sexes, in terms of the mass of the heart relative to body mass.

I refer to

• Eudorcas thomsonii thomsonii (0.94% with scant sexual difference),
• Litocranius walleri walleri (males 0.77%),
• Antidorcas marsupialis marsupialis (0.71% with no evidence yet of sexual difference), and
• N. g. granti (females 0.8%, males 0.65%).

A result is that adult males of N. g. granti (https://www.inaturalist.org/observations?taxon_id=601873), which resemble the pronghorn in body size and colouration, are indeed inferior to the antilocaprid in the mass of the heart relative to body mass. The values are respectively 0.65% and 0.95%.