Can PZP keep over-sexed rhesus macaques from taking over the Taj Mahal?
AGRA, India––Faster up a tree or the side of a building than a feral cat, biting more powerfully and often than any street dog, able to leap over monkey-catchers at a single bound, and usually able to outwit public officials, rhesus macaques might be capable of taking over many Indian cities.
But porcine zona pellucida (PZP) may be speeding to the rescue.
It works for wild horses
PZP is the same immuno-contraceptive feared and fought by wild horse advocates in the U.S. west, despite a 21-year history of success in controlling other wild horse populations and the populations of other species in zoos, mostly hooved animals.
PZP has not yet been used extensively in free-roaming non-human primates, but preliminary results have been promising enough that the Uttarakhand state forest department in early August 2016 announced trial of PZP in Dehradun, the state capital, in partnership with the Wildlife Institute of India.
“The vaccine will be mixed with food and will render the female infertile for a year,” Wildlife Institute of India director V.B. Mathur told Sharma Seema of The Times of India’s Kolkata bureau. “The dose will be repeated over a period of four years. The monkeys will either be tagged or identified from their traits.”
Surgery can’t catch up to repro rate
The Dehradun experiment was announced amid reports from Agra, in Uttar Pradesh state, site of the Taj Mahal, that a conventional surgical spay/neuter program begun in March 2016 appeared to be unable to keep up with the rhesus macaque reproduction rate.
“Terrifying as it sounds, the current population of monkeys in Agra, around 8,000, if allowed to grow unchecked, will exceed 216,000 within the next six years,” wrote Times of India correspondent Aditya Dev.
“Wildlife SOS has collaborated with the district administration and the Agra Development Authority to vaccinate and sterilize monkeys in the city,” Dev continued. “The situation, however, is fast slipping out of control.”
Bears & elephants
Wildlife SOS, a Delhi-based national organization, is best known for programs to take dancing bears and performing elephants off the streets of India, including managing sanctuaries for rescued bears and elephants, and programs to employ former performing bear and elephant handlers in other lines of work.
But Wildlife SOS originated as an arm of Friendicoes SECA, a Delhi dog-and-cat charity with extensive background in managing spay/neuter programs for dogs and cats. The Agra monkey project made use of some of the most experienced spay/neuter veterinarians in India.
“Under the pilot project, 552 monkeys have been trapped and 317 sterilized,” Wildlife SOS cofounder Kartick Satyanarayan told Dev. “This has prevented the exponential growth of [the rhesus macaque population by] about 7,200 monkeys over the next six years. And if the same statistical calculation is applied on the basis of natural history, biological behavior and reproduction pattern of rhesus macaques, Agra might have over 216,000 of them by 2022.”
Hanuman, the monkey god
“The target of more than 500 monkeys will be reached by the end of August,” Satyanarayan assured Dev. “The bigger worry is the reason behind the rapid increase in population: abundant food in the form of trash and offerings from devotees of Hanuman,” the Hindu monkey god.
But Hanuman emerged as a mythic figure in Vedic times, and has been worshipped as a deity for more than 1,200 years, possibly for millennia longer.
The chief reason for the recent macaque population explosion, not only in India but also in Indonesia, Malaysia, and other Southeast Asian nations, is a recent drastic decline in the numbers of free-roaming street dogs.
Dogs vs. monkeys
Partly this is because of the success of street dog sterilization programs, including the Indian national Animal Birth Control program, operating in most major cities since 2003. The Wildlife SOS sister charity, Friendicoes SECA, is among the ABC program service providers.
The ecological role of Indian street dogs relative to the habitat niche for rhesus macaques is threefold. As scavengers, street dogs consume edible refuse. As predators, street dogs hunt the rats and mice who infest the refuse piles and are also consumers of edible waste. In addition, as territorial pack animals, street dogs chase other scavengers and predators out of their habitat.
Monkeys and street pigs, in particular, have traditionally been controlled by the combination of dogs consuming the available food supply and ad hoc dog packs of dogs chasing them, usually formed through impromptu coalitions among dogs feeding from the same food sources.
Street ecology changing
Rhesus macaques, dogs, and pigs are not bitter enemies. Rhesus macaques are known to befriend dogs at times, and dogs in turn sometimes adopt and even nurse orphaned rhesus macaques. But rhesus macaques and dogs are normally territorial rivals, as are street dogs and pigs.
One dog tends to be no match for a troupe of macaques or herd of pigs, but several dogs usually prevail.
Now the Indian street ecology is abruptly changing. More streets are paved, discouraging pigs, who prefer muddy habitats where they can root and wallow. But as refuse collection has often not improved, more food waste is left to scavenge.
Roadkills & purges
Paved roads allow cars and trucks to go faster, posing a greater threat to dogs, who forage in the streets, and not long ago often napped in mid-intersection.
Beyond the growing vehicular threat to dogs, and the success of many Animal Birth Control programs, panic-driven purges following dog attacks at times sweep the streets of even sterilized dogs. Historically dog populations rebounded quickly from purges, but reduced reproductive capacity means slower rebounding, especially where the streets are busiest.
But the garbage remains, more abundant than ever, and rhesus macaques are quick to seize the opportunity, often taking arboreal routes––or routes over electric wires––above the traffic that hits their canine rivals. Frequently macaques detour into homes through open windows or balcony doorways.
Macaques declared vermin
Such incidents lead to frustration with macaque sterilization programs long before they reach the 70% threshold necessary to stop population growth of any species, from microbes to great whales.
Himachal Pradesh minister of environment, forests and climate change Thakur Singh Bharmouri, for instance, fed up with macaque raids and attacks in Shimla, the state capital city, “on March 14, 2016 declared the rhesus monkey as vermin within the municipal limits, which legally allows their elimination,” reported the Times of India.
“Permission to cull them will be valid for six months in the municipal limits[of Shimla] alone, excluding the forest areas,” the Times of India continued.
Rhesus macaques had not been culled since a court order stopped a previous culling program in 2011.
ABC success opened habitat
Ironically, a Shimla street dog sterilization program was stopped at about the same time, after sterilizing 5,800 dogs, believed to be about 80% of the dog population at the time the program began. The dog population has increased since then, to circa 3,500-4,000 as of the most recent available count, in October 2014, but even as the dog population rebounded, a much wider habitat niche had opened for rhesus macaques.
While street dogs continued to outnumber macaques, and to bite more people, Shimla deputy mayor Takinder Panwar told Anand Bodh of the Times of India that the Rippon Hospital, the major public hospital in the city, now treats about 60 macaque bite victims per month, compared to 100 dog bite victims.
Bharmouri told the Himachal Pradesh assembly in a written statement that monkeys, mostly rhesus macaques, had attacked 674 humans in 2013 through 2015. The victims had been paid compensation totaling more than $42,000.
51% of the macaques in the state were fixed
A surgical sterilization program operating at eight locations around Himachal Pradesh since 2006 had altered 108,325 macaques, Bharmouri said, amounting to 51% of the current population.
This reduced the Himachal Pradesh rhesus macaque count from 226,086 in 2013 to 207,614 in 2015, but even as the rural count dropped, the count within Shimla increased to 2,452, or about two monkeys for every three dogs.
Pressure to kill both street dogs and rhesus macaques often comes, throughout India, from organizations representing poor and illiterate members of the so-called “scheduled castes.” Politicians seeking the so-called “scheduled caste vote” frequently use community upset over dog attacks as a pretext for asserting that Animal Birth Control programs are a hobby of the rich, diverting funds from helping the poor, putting dog catchers out of work, exposing the poor to mauling and maimings, and chiefly benefiting veterinarians and makers of anti-rabies vaccine
“Dog menace” & “monkey menace”
Dog attacks and especially rabies cases have markedly decreased wherever ABC has been practiced successfully, but the allegations against ABC have gained political momentum, based on the argument that street dogs threaten the rights of poor people.
The same argument is increasingly often also advanced against monkeys.
As with street dogs, who are “the dog menace” to some, but are community pets to others, street monkeys have human friends and defenders, many of whom feed them.
In one extreme case, in Rohtas, a Patna suburb, a man named Dadan Singh “started off by feeding 45 monkeys, but now there are 772,” he told Ramlala Singh and Prabhakar Kumar of CNN in April 2007. “Feeding so many monkeys is not an easy task,” Singh added. “But most households of the village contribute,” he said, “and they do it willingly,” apparently believing that feeding rhesus macaques is winning favor with Hanuman.
Not a new issue
Non-recognition of the relationship between Indian street dog purges and monkey invasions is no new phenomenon–and not only Indians have failed to observe it.
Separate articles on page 22 of the July 1938 edition of the National Humane Review, published by the American Humane Association, detailed a dog pogrom in Chennai, then called Madras, and described the industry of shipping monkeys to U.S. laboratories that had emerged in several leading Indian cities.
Neither the British correspondents who furnished the information nor the Americans who wrote the articles appeared to be aware that one practice might be fueling the other.
Dogs electrocuted, macaques sold to labs
“Stray dogs are a problem in India, as in our own country,” the editors observed, “and city handling in India is as revolting as in many American cities. Through the endeavors of the Madras SPCA, electrocution has taken the place of clubbing dogs to death,” not to be abolished until after the Blue Cross of India introduced the first city-wide Animal Birth Control program in India in 1996, following 32 years of more limited trials.
Trying to stop the macaque export trade was the special concern of a Miss Howard Rice, of Pune, a port city south of Mumbai (formerly called Bombay), on the far side of India from Chennai.
Rice in 1937 won a temporary suspension of the macaque traffic during the summer months. The trade was finally stopped entirely in 1978, through the combined efforts of the Blue Cross of India and the International Primate Protection League.
However, as urban macaques have proliferated in recent years, political arguments for reviving macaque exports to labs have resurfaced, along with occasional arguments for exporting street dogs to places where dogs are eaten. Neither practice could actually occur legally without amendments to national laws.