Endangered Species Monday: Phalacrocorax carunculatus
This Mondays (ESP) Endangered Species watch Post is dedicated to the Rough Faced Shag, scientifically known as Phalacrocorax carunculatus. Identified back in 1789 by Professor Johann Friedrich Gmelin (8 August 1748 – 1 November 1804) was a German naturalist, botanist, entomologist, herpetologist and malacologist. (Image credited: Jim Scarff 2010)
Listed as (vulnerable) the Rough Faced Shag doesn’t appear to be listed on either appendix (I) or (II). This Monday I have chosen to document on P. carunculatus as the species is incredibly rare. Thankfully conservation efforts and improvements in relation to protection of habitat have finally stabilized the birds population count. For once in many of my articles I can finally write on a bird that’s populations are not in decline. However, as explained the species is considered one of New Zealand’s rarest specimens.
Endemic to New Zealand the species derives from the family of Phalacrocoracidae. Locals commonly refer to the species by other names such as; New Zealand King Shag or King Shag. P. carunculatus qualified for the listing of vulnerable due to its very small (stable) population size where its restricted to four islands only.
From 1992 to 2002 the estimated number of birds living on all four islands stood at a mere c645 individuals (Est). A further 100-130 breeding pairs were counted too, which is equates (roughly) to 299-1000 ‘mature individuals’. Taking all individuals and breeding pairs into consideration followed up with the last census, it concluded that some 375- 1500 individuals remain on all four islands. Had drastic conservation measures not been implemented the species could have gone extinct.
Conservation practices on all four islands have been undertaken extremely well despite the fact populations are depressed. I personally applaud the New Zealand Government and Department of Environment for their efforts, and thank them for continuing future conservation and bird management projects.
Image: Rough Faced Shag small colony.
92% of the population resides on White Rocks, Sentinel Rock, Duffers Reef and Trio Islands, in the Marlborough Sounds, with two smaller colonies off D’Urville Island. Furthermore surveys on islands have confirmed that populations have remained stable over the last fifty years.
Breeding normally occurs on small rock stacks and islets, the primary diet component is said to be left eyes flatfish. However the Rough Faced Shag will also feed on other marine aquatic specimens too.
Colonies now reside within wildlife sanctuaries that are clearly signposted on the islands reminding tourists and any wannabe poachers to stay clear of Rough Faced Shag habitat. Bird watchers are also reminded to stay clear of habitat, especially when breeding occurs due to the species being very sensitive to human disturbance. I am somewhat concerned as to how a tourist has been able to edge so close the colony within the image above. This isn’t good and as such enforcement teams must remind tour operators of the (code of conduct).
Conservation actions that are now underway include a census count every five years and, monitoring of vessels that can/do cause habitat disturbance. Furthermore development of techniques to establish new colonies of Rough Faced Shags elsewhere for future survival. A code of conduct has been established to (remind commercial boats, fishing-people and tour operators) of their obligations and duties to ensure Rough Faced Shags are not pressurized by human disturbance.
Protection of all breeding grounds has most likely been sought since last documentation on the species (2012). Prevention of marine farming next to ‘any’ colonies breeding or non-breeding and responsible fishing programs have been rolled out minimize by-catch thus ensuring the birds food source requirements are not depleted or harmed in anyway.
In the 1800s, collecting by ornithologists and hunting for the fashion trade may have affected numbers. Human disturbance (boats, aircraft and scuba divers) can cause desertion of nests and subsequent predation by gulls. New interest from tour operators in the region may increase the problem. Set-nets are sometimes placed very close to colonies and present a major risk. Birds are occasionally illegally shot. Probably the largest threat now is that of tourists or fishermen disturbing breeding and non-breeding colonies. Hence why conservation measures have been put into practice to remind and keep tourists and fisherman away from all inhabitant islands.
Thank you for reading.
Dr Jose C. Depre
Environmental and Botanical Scientist.