ארכיון יומן של אוקטובר 2020

אוקטובר 02, 2020

The mystery of the Arabian miniatures

The Arabian peninsula is bigger than western Europe, and ecologically similar to North Africa. However, an unexplained fact is that most of its species of large terrestrial animals are diminutive.

Five of the six wild species of ungulates, and both of the top carnivores, are smaller than the key deer (https://en.wikipedia.org/wiki/Key_deer), an extremely diminutive form restricted to small islands off Florida.

The wild ungulates and the major Carnivora of the Arabian peninsula are all smaller than conspecifics, or their closest ecological counterparts, in Africa or mainland Asia. The same was true for the extinct Arabian form of the ostrich (Struthio camelus, https://en.wikipedia.org/wiki/Arabian_ostrich). This means that there is/was no wild species of herbivore on the Arabian Peninsula with adult female body mass averaging more than 65 kg.

Accordingly, the lion (Panthera leo) seems to have been naturally absent from the Arabian Peninsula (file:///C:/Users/Antoni%20Milewski/Downloads/TheAsiaticorPersianLioninPalestineArabianIslamicRegion.pdf). Far from compensating for this absence by increased body size, the Arabian leopard (Panthera pardus nimr) is the smallest subspecies: adult females about 20 kg. The Arabian wolf likewise weighs only about 20 kg.

This means that both of the top predators of the Arabian Peninsula are only about the size of the Eurasian lynx (Lynx lynx).

The following illustrates the various species.

Gazella saudiya is extinct, with no photos of the living animal (https://en.wikipedia.org/wiki/Saudi_gazelle). It was the smallest of all gazelles, with adult female body mass probably less than 13 kg.

Gazella arabica has adult female body mass probably about 15 kg. See https://www.zoochat.com/community/media/arabian-mountain-gazelle-gazella-gazella-cora.421165/ and https://www.shutterstock.com/nb/image-photo/extremely-shy-wild-female-dorcas-gazelle-387163744 and https://www.biolib.cz/en/image/id171988/ and https://www.shutterstock.com/nb/image-photo/male-arabian-mountain-gazelle-gazella-cora-1139195546 and http://shahbazmuhammed.blogspot.com/2015/03/arabian-mountain-gazelle.html

Gazella marica has adult female body mass probably about 18 kg. See https://1.bp.blogspot.com/-sb9jKDyMmzU/XzaWasrR8gI/AAAAAAAAi3Y/6KJLfUB4qWkauKq96yj0c_XTGKDZG3hIwCLcBGAsYHQ/s1600/Arabian%2BSand%2BGazelle1.jpg and https://4.bp.blogspot.com/-kysR7MF0juA/UzBTOxNvP6I/AAAAAAAAPso/megatJCItzI/s3200/Sand_Gazelle1.jpg and https://calphotos.berkeley.edu/cgi/img_query?enlarge=0000+0000+1115+1312 and http://awwp.alwabra.com/wp-content/uploads/2014/04/Adult_Male_Rheem_Gazelle_01.jpg

Capra nubiana has adult female body mass about 23.5 kg (https://cdnsciencepub.com/doi/pdf/10.4141/cjas84-204), which is small compared to Capra ibex of Europe or Capra walie of Ethiopia. See https://www.dreamstime.com/male-nubian-ibex-walking-along-mountain-rocks-showing-off-large-curved-horns-capra-nubiana-al-ain-zoo-image151878031 and https://www.naturepl.com/stock-photo-nubian-ibex-capra-nubiana--old-male-walking-on-a-rock-negev-desert-nature-image01667947.html and https://www.naturepl.com/stock-photo/nubian-ibex-(capra-nubiana)-male-walking-in-dry-environment-negev-desert/search/detail-0_01667943.html and https://stock.adobe.com/search/images?k=ibex+isolated&asset_id=246925501

Oryx leucoryx (which narrowly escaped extinction) has adult female body mass about 63 kg (https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0180269#:~:text=The%20mean%20body%20mass%20of,%3D%206%2C%20range%2048%E2%80%9390). See https://www.alamy.com/arabian-oryx-white-oryx-walking-through-desert-in-yotvata-hai-bar-nature-reserve-breeding-and-reacclimation-center-oryx-leucoryx-image342292900.html and https://www.desicomments.com/animals/white-oryx-on-sand/ and https://www.istockphoto.com/photo/endangered-arabian-or-white-oryx-walks-along-the-desert-in-the-united-arab-emirates-gm1141255843-305683103 and https://www.freeimages.com/premium/arabian-oryx-1601835

Arabitragus jayakari has adult female body mass about 20 kg (https://www.biorxiv.org/content/10.1101/2021.01.26.428299v1.full.pdf). See https://www.mammalwatching.com/2018/06/12/infos-and-pics-on-arabian-tahr/ and https://www.biolib.cz/en/image/id373892/ and https://www.biolib.cz/en/image/id366322/ and https://colnect.com/en/phonecards/phonecard/32140-Arabian_Tahr-1993_The_Rare_And_The_Beautiful-Omantel-Oman and https://www.alamy.com/arabian-tahr-arabitragus-jayakari-male-captive-oman-october-image357523434.html and https://www.fujairahobserver.com/2021/08/02/fujairahs-fauna-and-flora-3/

Panthera pardus https://www.dreamstime.com/stock-photo-arabian-leopard-looking-prey-image86330372and https://gulfnews.com/world/gulf/oman/catching-the-endangered-arabian-leopard-on-camera-1.1392145 and https://en.wikipedia.org/wiki/Arabian_leopard#/media/File:PikiWiki_Israel_14861_judean_desert_leopard_cropped.JPG

Caracal caracal schmitzi https://www.pumapix.com/wild-cat-profile-arabian-caracal/

Acinonyx jubatus (locally extinct) was smaller-bodied on the Arabian Peninsula than elsewhere.

Canis lupus arabs https://en.wikipedia.org/wiki/Arabian_wolf

Vulpes vulpes arabica has adult body mass about 2.7 kg (https://en.wikipedia.org/wiki/Arabian_red_fox).

Hyaena hyaena sultana has average adult body mass about 31 kg (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6662563/). See https://www.birdsofsaudiarabia.com/2020/07/striped-hyena-abha.html and https://www.zoochat.com/community/media/arabian-striped-hyena.404031/ and https://www.zoochat.com/community/media/arabian-striped-hyena.172934/ and https://www.researchgate.net/publication/341725041_The_Arabian_Striped_Hyaena_Hyaena_hyaena_sultana_Pocock_1934_Carnivora_Hyaenidae_in_the_Kingdom_of_Saudi_Arabia_aldb_almukhtt_alrby_fy_almmlkt_alrbyt_alswdyt#:~:text=There%20are%205%20subspecies%20of%20Striped%20Hyena%3A&text=Arabian%20Striped%20Hyaena%20(Hyaena%20hyaena%20sultana%20Pocock%2C%201934)%20%E2%80%93,March%202020%2C%20April%202020 and https://www.researchgate.net/publication/254163197_Hyaena_hyaena/link/5624c66508aea35f2686a9ad/download.

One of the reasons why this 'miniaturisation' is poorly appreciated is that some of the species listed above lack the body proportions usually associated with reduction in body size, such as large-looking heads and eyes and short-looking legs and horns. The Arabian oryx has proportionately shorter legs than those of its Saharan relative, but its body mass still surprises: only about half that of Oryx dammah (compare https://www.stevebloom.com/index.php?page=single&id=510206-BS1 with https://www.alamy.com/scimitar-horned-oryx-walking-through-negev-desert-in-yotvata-hai-bar-nature-reserve-breeding-and-reacclimation-center-oryx-dammah-image342292910.html). Gazella arabica (https://www.pixoto.com/images-photography/animals/other-mammals/arabian-gazelle--6523769179602944) is similarly gracile to the large African gazelle Nanger granti (https://www.flickr.com/photos/antpitta/28789223187/), despite having a body mass about threefold smaller.

Reduction in body size is a familiar pattern on islands, usually explained by limitation on resources in confined areas. This can theoretically apply to peninsulas too, inasmuch as peninsulas produce isolation from mainlands. And a further parallel with islands is the tendency of the fauna to be driven rapidly to extinction by human hunters.

However, isolation is an unsatisfactory explanation for the remarkably consistent diminution in the Arabian fauna, because this peninsula is larger than any island on Earth (https://www.newsweek.com/true-scale-map-world-shows-how-big-countries-really-are-1183386). Even allowing that aridity limits the productivity and reliability of resources, how can the effects have been so different from the Sahara?

The mystery of the Arabian miniatures remains an intriguing puzzle for naturalists to ponder.

פורסם ב אוקטובר 02, 2020 12:53 אחה"צ על־ידי milewski milewski | 6 comments | הוספת תגובה