Biology:Philippine crocodile

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Short description: Species of crocodile

Philippine crocodile
Temporal range: Late PleistocenePresent, 0.1–0 Ma[1]
Crocodylus mindorensis by Gregg Yan 01.jpg
An adult basking on the island of Palawan, Philippines
CITES Appendix I (CITES)[3]
Scientific classification edit
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Clade: Archosauromorpha
Clade: Archosauriformes
Order: Crocodilia
Family: Crocodylidae
Genus: Crocodylus
Species:
C. mindorensis
Binomial name
Crocodylus mindorensis
Schmidt, 1935
Distribution crocodylus mindorensis.PNG
Range of the Philippine crocodile in blue

The Philippine crocodile (Crocodylus mindorensis), also known as the Mindoro crocodile, the Philippine freshwater crocodile, the bukarot[4] in Ilocano, and more generally as a buwaya in most Filipino lowland cultures,[4] is one of two species of crocodiles found in the Philippines ; the other is the larger saltwater crocodile (Crocodylus porosus).[5][6] The Philippine crocodile, the species endemic only to the country, went from data deficient to critically endangered in 2008 from exploitation and unsustainable fishing methods,[7] such as dynamite fishing.[8] Conservation methods are being taken by the Dutch/Filipino Mabuwaya foundation,[9] the Crocodile Conservation Society and the Zoological Institute of HerpaWorld in Mindoro island. It is strictly prohibited to kill a crocodile in the country, and it is punishable by law.

Taxonomy

Until 1989, it was considered a subspecies of the New Guinea crocodile (Crocodylus novaeguineae).[10] They are now recognized as closely related but separate species.[11]

Evolution

The genus Crocodylus likely originated in Africa and radiated outwards towards Southeast Asia and the Americas,[12] although an Australia/Asia origin has also been considered.[13] Phylogenetic evidence supports Crocodylus diverging from its closest recent relative, the extinct Voay of Madagascar , around 25 million years ago, near the Oligocene/Miocene boundary.[12]

Phylogeny

Below is a cladogram based on a 2018 tip dating study by Lee & Yates simultaneously using morphological, molecular (DNA sequencing), and stratigraphic (fossil age) data,[14] as revised by the 2021 Hekkala et al. paleogenomics study using DNA extracted from the extinct Voay.[12]

Crocodylinae

Voay

Crocodylus

Crocodylus anthropophagus

Crocodylus thorbjarnarsoni

Crocodylus palaeindicus

Crocodylus Tirari Desert

Asia+Australia

Crocodylus johnstoni Freshwater crocodile Freshwater crocodile white background.jpg

Crocodylus novaeguineae New Guinea crocodile

Crocodylus mindorensis Philippine crocodile

Crocodylus porosus Saltwater crocodile Crocodylus porosus white background.jpg

Crocodylus siamensis Siamese crocodile Siamese Crocodile white background.jpg

Crocodylus palustris Mugger crocodile Mugger crocodile white background.jpg

Africa+New World

Crocodylus checchiai

Crocodylus falconensis

Crocodylus suchus West African crocodile

Crocodylus niloticus Nile crocodile Nile crocodile white background.jpg

New World

Crocodylus moreletii Morelet's crocodile

Crocodylus rhombifer Cuban crocodile Cuban crocodile white background.jpg

Crocodylus intermedius Orinoco crocodile

Crocodylus acutus American crocodile American crocodile white background.jpg

Characteristics

The Philippine crocodile is a crocodilian endemic to the Philippines. It is a relatively small, freshwater crocodile. It has a relatively broad snout and thick bony plates on its back (heavy dorsal armor). This is a fairly small species, reaching breeding maturity at 1.5 m (4 ft 11 in) and 15 kg (33 lb) in both sexes. A 69-kilogram (152 lb) individual was found to have a bite force of 2,736 N (615 lbf).[15] Adults rarely exceed 2.7 m (8 ft 10 in) and 90 kg (200 lb), and only the largest males attain record maximum size of up to 3.5 m (11 ft), perhaps reaching the maximum weight of 210 kg (460 lb) in exceptional individuals.[16] Females are slightly smaller than males. Philippine crocodiles are golden-brown in color, which darkens as they mature.

Distribution and habitat

The Philippine crocodile has been extirpated in Samar, Jolo, Negros, Masbate, and Busuanga. Populations still survive in the Northern Sierra Madre Natural Park within the Luzon rainforest, San Mariano, Isabela, Dalupiri island in the Babuyan Islands, Abra (province) in Luzon and the Ligawasan Marsh, Lake Sebu in South Cotabato, Pulangi River in Bukidnon, Paghungawan Marsh in Siargao Island, and possibly in the Agusan Marsh Wildlife Sanctuary in Mindanao.[10][17][18] The Philippine crocodile wildlife populations that reside in these locations live geographically isolated from each other, which ultimately impacts their population level differentiation and decreases genetic diversity.[19] It was historically found in parts of Visayas and until the numbers were drastically cut by, mainly, habitat destruction. These crocodiles eat ailing fish in a significantly higher proportion than healthy fish, thus improving the common health of the fish stock. By preying on the most common fish, they balance the fish population; any species which suddenly becomes dominant is put back in its proper proportion. Crocodile droppings are nutritious for the fish and contain critically important chemicals.

Conservation status

A Philippine crocodile swimming stealthily

Crocodylus mindorensis is considered to be the most severely threatened crocodile species in the world, listed as critically endangered by the IUCN.[2] A population estimate of 100 non-hatchling individuals underlines the critical status of the species.[20] Although this species was once found over the whole of the Philippines, it is now critically endangered. In addition, very little is known about the natural history or ecology of the species, or its relationship with Crocodylus porosus, whose range it overlaps. More surveys are required to determine the present range. Initial population reduction was through commercial exploitation, although the current threat is mainly from removal of suitable habitat for agricultural purposes to satisfy a rapidly expanding human population. Governmental support for any conservation measures is limited, and the crocodiles are often killed by the local populace. Long-term captive breeding and release (through PWRCC, Silliman University, and international breeding centres) is judged to be the best course to take at present, although a management program is imperative for the remainder of the wild population (most of which reside in only one protected area). In 1992, fewer than 1000 animals were estimated to remain in the wild. In 1995, that estimate was revised to be no more than 100 nonhatchlings (hatchlings are rarely counted in surveys because their survival rate is so low). One of the threats to the diminishing population of Philippine crocodile is because it is misunderstood. In mainstream Filipino society, crocodiles are considered dangerous man-eaters and compared to corrupt government officials and law enforcers. They are respected by the indigenous community: in research conducted among permanent residents of Lake Panlabuhan, a tributary of the famous Agusan Marsh, the acceptance of the crocodiles among these residents is very high and their risk perception is very low. However, the crocodile have an image problem with outsiders. To many, they are viewed as man-eaters. In reality, the crocodile is small and will not attack people unless provoked.

Since October 2021, C. mindorensis has been classified as Critically Depleted by the IUCN.[21]

The killing of crocodiles seems to be the major cause of the decreasing number of this species. In northeast Luzon, a community-based conservation approach developed under the Crocodile Rehabilitation Observance and Conservation (CROC) project was adopted with the aim of reaching sustainable co-habitation of crocodiles and local people.[20]

A juvenile

In 2007, a specialist group was founded by several people within the Philippines, involved in crocodilian conservation. The Crocodile Conservation Society Philippines and the Zoological Institute of HerpaWorld are working on conservation breeding and release programs. C. mindorensis was considered locally extinct in part of its former range in northern Luzon until a live specimen was caught in San Mariano, Isabela, in 1999. That individual, nicknamed 'Isabela' by its captors, was given to the care of the Crocodile Rehabilitation Observance and Conservation until it was released in August 2007. The specimen was 1.6 m long at the time of its release.[22]

The Philippine crocodile became nationally protected by law in 2001 with the enactment of Republic Act 9147 known as the Wildlife Act. It is punishable to kill a crocodile, with a maximum penalty of ₱100,000 (equivalent to about $2,500).[10] The Philippine Senate introduced resolution no. 790 on May 31, 2012, to further strengthen and augment existing laws for the protection of the Philippine crocodile and the saltwater crocodile.[23]

Media

This crocodile was featured in National Geographic's Dangerous Encounters hosted by crocodile specialist Dr. Brady Barr. In one of the episodes, Barr sought to be the first person to see all species of crocodiles in the world. Fortunately, he was able to see a Philippine crocodile that was about two weeks old.[24]

The hatching of a Philippine crocodile was recorded in GMA News Born to Be Wild. They also recorded that tropical fire ants, an invasive species, eat unhatched endangered bukarot eggs. The media team saved a nest from a fire ant attack. Also recorded were adult Philippine crocodiles.[25]

Common names

Aside from the general term buwaya or buaya (which generally apply to C. porosus but can also apply to C. mindorensis in languages where the two species are not differentiated), they were known by various names throughout the islands. In Spanish colonial records, the two species were often differentiated as cocodrilo (for C. porosus) and caimán for (for C. mindorensis), but this distinction is not followed by English dictionaries and translations.[26]

In northen Luzon, Cagayan Valley, and the Sierra Madre mountain range, they were known as bukarot or bokarot in Ilocano, Isneg, Ibanag, and Yogad; lamag in Itawis, Yogad, Dupaningan Agta, and Kalinga; and lamig in Gaddang.[26]

In southern Luzon and the central islands of the Philippines, they were known also known as tigbin in Tagalog; barangitaw in Bikol, Mangyan, and Eastern Visayas; balanghitao or balangita in Cebuano and Central Visayan languages; and also burangas or burangaris in Mangyan.[26]

In Mindanao and Palawan, they are known as nguso in Agusan Manobo; sapding in Mandaya; balangitao or dagorogan in Maranao; bungut in Batak; and bungot in Tagbanwa.[26]

Mythology, folklore and cultural significance

In the pre-colonial anito beliefs throughout the Philippine islands, crocodiles (both C. mindorensis and C. porosus) were feared and revered, which played a key role in their survival up until modern times. The Spanish recorded that rivers and lakes were filled with crocodiles, and people often lived and fished close to them, which alarmed most European observers. Some communities put up small bamboo fences to keep crocodiles out from certain areas and people avoided provoking them, but in general, they didn't take many specific precautions against them. There was an unspoken "peace pact" between crocodiles and people. There were very strict taboos against killing crocodiles or eating crocodile meat. And crocodiles which attack or kill a person are always killed by the community.[26]

It was widely believed that crocodiles never attacked people arbitrarily. Thus attacks by crocodiles were regarded with fatalistic attitudes, as being the fault of the victim for transgressing taboos, or as punishment by the spirits for breaking an oath. The Spanish conquistador Miguel López de Legazpi records in 1571 that his treaties with Sulayman, Ache, and Lakandula of Manila and Tondo were sworn on the condition that they would die and be eaten by crocodiles if they break the agreements. Regardless, being eaten by a crocodile was regarded as an honorable death, as it ensured that the soul of the person would be safely transported to the spirit world by the crocodile via the rainbow.[26]

Crocodiles regarded with superstition can be generally divided into three kinds: crocodiles which are reincarnations of ancestors (anito), embodiments of powerful nature spirits (diwata), or shapeshifted malevolent spirits or witches (aswang). Not all crocodiles are seen as personifications of these three, but crocodiles with extraordinary traits, like being very large, being uncharacteristically docile, having strange coloration, being crippled or having visible birth defects, are often regarded as such. In several creation myths of the islands, the creator deity is a crocodile, and crocodiles were often seen as guardians of the spirit world (where the dead go) and psychopomps who lead the spirits of the dead safely. Crocodiles were also believed to also exist in a sort of parallel spirit world, often interpreted as an underwater village. Several ethnic groups also consider crocodiles to be their direct ancestors, and datu and warriors often traced their lineage to crocodiles. Crocodiles were also often addressed with kinship titles like nono ("grandfather").[26]

Depictions of crocodiles were commonly carved into coffins or woven into funeral clothes to protect the spirit of the deceased. Crocodile teeth were also commonly worn as agimat (amulets) for protection against disease and evil spirits.[26]

In modern Filipino culture, crocodiles are perceived negatively. They are regarded as vermin and a threat to small children and livestock. They are also associated with greed, deceit, corruption, and nepotism. The term buwaya is frequently used as an insult for corrupt politicians and government officials, moneylenders, and the police.[26][27]

References

  1. Rio, Jonathan P.; Mannion, Philip D. (6 September 2021). "Phylogenetic analysis of a new morphological dataset elucidates the evolutionary history of Crocodylia and resolves the long-standing gharial problem". PeerJ 9: e12094. doi:10.7717/peerj.12094. PMID 34567843. 
  2. 2.0 2.1 van Weerd, M.; C. Pomaro, C.; de Leon, J.; Antolin, R.; Mercado, V. (2016). "Crocodylus mindorensis". IUCN Red List of Threatened Species 2016: e.T5672A3048281. doi:10.2305/IUCN.UK.2016-3.RLTS.T5672A3048281.en. https://www.iucnredlist.org/species/5672/3048281. Retrieved 19 November 2021. 
  3. "Appendices | CITES". https://cites.org/eng/app/appendices.php. 
  4. 4.0 4.1 "Crocodile Surveys - iucncsg.org"
  5. "Only in the Philippines - Endemic Animals in the Philippines" . TxtMania.com. Retrieved on 2007-10-22.
  6. Ross, Charles A. "Crocodile Status in Ligawasan Marsh". Philippine Crocodile. Retrieved on 2012-07-12.
  7. "Crocodilian Species - Philippine Crocodile (Crocdylus mindorensis)". Crocodilian Species List. Retrieved on 2007-10-22.
  8. "Wildlife Conservation in the Philippines". BP.com. Retrieved on 2007-10-22.
  9. "Philippine Crocodile Comeback" . cepf.net. Retrieved on 2007-10-22.
  10. 10.0 10.1 10.2 Van Weerd, Merlijn "Philippine Crocodile (Crocodylus mindorensis)". Crocodile Specialist Group.
  11. Britton, Adam (2009-01-01). "New Guinea Crocodile". Crocodilians: Natural History & Conservation. Florida Museum of Natural History. http://crocodilian.com/cnhc/csp_cnov.htm. 
  12. 12.0 12.1 12.2 Hekkala, E.; Gatesy, J.; Narechania, A.; Meredith, R.; Russello, M.; Aardema, M. L.; Jensen, E.; Montanari, S. et al. (2021-04-27). "Paleogenomics illuminates the evolutionary history of the extinct Holocene "horned" crocodile of Madagascar, Voay robustus" (in en). Communications Biology 4 (1): 505. doi:10.1038/s42003-021-02017-0. ISSN 2399-3642. PMID 33907305. 
  13. Oaks, Jamie R. (2011). "A time-calibrated species tree of Crocodylia reveals a recent radiation of the true crocodiles". Evolution 65 (11): 3285–3297. doi:10.1111/j.1558-5646.2011.01373.x. PMID 22023592. 
  14. Michael S. Y. Lee; Adam M. Yates (27 June 2018). "Tip-dating and homoplasy: reconciling the shallow molecular divergences of modern gharials with their long fossil". Proceedings of the Royal Society B 285 (1881). doi:10.1098/rspb.2018.1071. PMID 30051855. 
  15. Erickson, G. M.; Gignac, P. M.; Steppan, S. J.; Lappin, A. K.; Vliet, K. A.; Brueggen, J. A.; Inouye, B. D.; Kledzik, D. et al. (2012). "Insights into the ecology and evolutionary success of crocodilians revealed through bite-force and tooth-pressure experimentation". PLOS ONE 7 (3): e31781. doi:10.1371/journal.pone.0031781. PMID 22431965. Bibcode2012PLoSO...731781E. 
  16. Michael Vincent F. Cruz, Alfonso G. Biñan, Jr. and Pedro G. Mendoza"].[1]. [2] IUCNSSC Crocodile Specialist Group.
  17. "Info". www.iucncsg.org. http://www.iucncsg.org/365_docs/attachments/protarea/Page-843dd0aa.pdf. 
  18. "Manila Proceedings.indd". http://www.iucncsg.org/365_docs/attachments/protarea/Proc-17f3b2b9.pdf. 
  19. Tabora. (2012). Detection of Crocodylus mindorensis x Crocodylus porosus (Crocodylidae) hybrids in a Philippine crocodile systematics analysis. ZOOTAXA, 3560, 1–31.
  20. 20.0 20.1 van Weerd, Merlijn; van der Ploeg, Jan (2004-01-01). "A new future for the Philippine crocodile, Crocodylus mindorensis". Sylvatrop 13: 31–50. https://www.researchgate.net/publication/235800476. 
  21. van Weerd, M.; Gatan-Balbas, M. (2021). "Crocodylus mindorensis (Green Status assessment)". IUCN Red List of Threatened Species 2021: e.T5672A567220213. https://www.iucnredlist.org/species/5672/567220213. Retrieved 15 January 2022. 
  22. Burgonio, TJ (2007-08-25). "'Isabela,' the croc, to be freed in wilds". Breaking News: Regions (Inquirer.net). http://newsinfo.inquirer.net/breakingnews/regions/view_article.php?article_id=84577. 
  23. (2012-05-31). "Senate P.S.R. 790". Senate of the Philippines 15th Congress. Retrieved on 2012-07-16.
  24. National Geographic Channel Videos - Adventure Shows, Natural History & More channel. National Geographic. Retrieved on 2007-10-22.
  25. "Born to Be Wild: Actual hatching of a Philippine crocodile". YouTube. 2017-08-14. https://www.youtube.com/watch?v=26Rm86ZoZj4. 
  26. 26.0 26.1 26.2 26.3 26.4 26.5 26.6 26.7 26.8 Van Der Ploeg, Jan; Van Weerd, Merlijn; Persoon, Gerard A. (2011). "A Cultural History of Crocodiles in the Philippines: Towards a New Peace Pact?". Environment and History 17 (2): 229–264. ISSN 0967-3407. https://www.jstor.org/stable/41303508. 
  27. Madarang, Catalina Ricci S. (2021-06-23). "Crocodiles are not hated creatures, symbols of corruption centuries ago. Here's why." (in en-US). https://interaksyon.philstar.com/hobbies-interests/2021/06/23/194515/crocodiles-are-not-hated-creatures-symbols-corruption-centuries-ago-heres-why/. 

Further reading

External links

  • Mabuwaya Foundation [1]

Wikidata ☰ Q272402 entry