Work con­tin­ues af­ter set­backs for rein­tro­duc­ing black-footed fer­rets in Grass­lands Na­tional Park

Prairie Post (East Edition) - - NEWS - By Matthew Lieben­berg mlieben­[email protected]­t.com

The high-pitched chat­ter of black-footed fer­rets has once again fallen silent on the Saskatchew­an prairie, but ef­forts are con­tin­u­ing to rein­tro­duce this en­dan­gered species to Grass­lands Na­tional Park.

A to­tal of 74 fer­rets were re­leased in the park over a four-year pe­riod from 2009 to 2012, but they have not been seen for sev­eral years and it is as­sumed they have all died.

Sherri Clif­ford, man­ager of re­source con­ser­va­tion at Grass­lands Na­tional Park, said the re­cov­ery strat­egy for black-footed fer­ret has been put on hold for the mo­ment.

“We’re learn­ing all the time,” she noted. “I think what I’ve learned from all of this is that once a species is gone, re­cov­er­ing it is ex­tremely dif­fi­cult and in­deed it’s heart­break­ing at times.”

The black-footed fer­ret is North Amer­ica’s only na­tive fer­ret species and be­fore their near ex­tinc­tion they were found through­out the short grass prairie. Their habi­tat be­came increasing­ly frag­mented due to hu­man ac­tiv­i­ties and their main food source, black­tailed prairie dogs, were also dis­ap­pear­ing.

The last wild black-footed fer­ret in Canada was seen in 1937 and for some time con­ser­va­tion­ists thought the species had be­come ex­tinct in North Amer­ica. In 1981 a small pop­u­la­tion was found near a ranch in Mee­teetse, Wy­oming. Sev­eral fer­rets were trapped and they were used to start a suc­cess­ful cap­tive breed­ing pro­gram.

“Cap­tive bred de­scen­dants of those fer­rets were re­leased into the wild in Wy­oming, Mon­tana and South Dakota, and then the Toronto Zoo be­gan breed­ing in 1992,” she said.

Their reintroduc­tion to Canada took place in 2009, when 34 were re­leased in Grass­lands Na­tional Park. Ad­di­tional an­i­mals were re­leased in the fol­low­ing three years, start­ing with 15 in 2010, an­other 15 in 2011, and 10 in 2012.

One of the high­lights of the re­cov­ery strat­egy oc­curred early on, when wild-born fer­rets were ob­served in 2010.

“That demon­strated to us that it was pos­si­ble for cap­tive born an­i­mals to re­pro­duce and that we could have truly wild lit­ters in the park,” she said. “So that was re­ally en­cour­ag­ing and a big high­light.”

A con­flu­ence of fac­tors over sev­eral years cre­ated con­cerns about the wel­fare of the fer­rets in the park, and that caused the sus­pen­sion of any ad­di­tional fer­ret re­leases af­ter 2012. Even­tu­ally the mon­i­tor­ing pro­gram was also put on hold in 2016 af­ter there were no fur­ther fer­ret sightings.

“Dur­ing those four years of re­leases we had two se­vere droughts,” she said. “Those droughts re­sulted in a low win­ter sur­vival and then low re­pro­duc­tion of prairie dogs in the year fol­low­ing the drought, and this is a preda­tor-prey sys­tem. The fer­rets are de­pen­dent on the prairie dogs.”

The black-tailed prairie dog pop­u­la­tion in the park ex­pe­ri­enced a fur­ther de­cline af­ter syl­vatic plague, a bac­te­rial dis­ease in wildlife, was de­tected in 2010.

“We think that it’s some­thing that har­bours in the en­vi­ron­ment all the time, and then some­times we have an out­break,” she said. “We sus­pect that one of the fac­tors that leads to those out­breaks can be things like drought fol­lowed by higher pre­cip­i­ta­tion, dif­fer­ent stres­sors in the en­vi­ron­ment, and so we’re mon­i­tor­ing for that all the time.”

That syl­vatic plague out­break helped to re­duce the main food source of the fer­rets and at the same time they were also sus­cep­ti­ble to the dis­ease. All of this hap­pened too soon af­ter the reintroduc­tion of the fer­rets to Grass­lands Na­tional Park, and they did not have enough time to in­crease their pop­u­la­tion.

“Then the other thing is just that they have a re­ally short life­span,” Clif­ford said. “We es­ti­mate that they prob­a­bly live in the wild for three to four years. So they re­ally need to be aug­mented in order to have any chance of es­tab­lish­ing a wild pop­u­la­tion.”

One of the chal­lenges for con­ser­va­tion­ist when they want to cre­ate good habi­tat con­di­tions for fer­rets is that they re­quire a lot of space. Each breed­ing fe­male fer­ret needs about 55 to 80 hectares of habi­tat to meet her re­quire­ments to feed and raise her lit­ter.

“So that would mean that we would need to have about 4,000 hectares of habi­tat for a small but vi­able fer­ret pop­u­la­tion, and we cur­rently have 1,000 hectares,” she said.

The in­ten­tion is to re­sume the re­cov­ery strat­egy for black-footed fer­rets in the fu­ture, but only af­ter there is greater cer­tainty that their habi­tat needs can be met. Parks Canada has there­fore de­cided to fo­cus on cre­at­ing a healthy black-tailed prairie dog pop­u­la­tion, be­cause they are such an im­por­tant part of the fer­ret habi­tat. There are cur­rently 18 prairie dog colonies in Grass­lands Na­tional Park, and there are also two colonies out­side the park on com­mu­nity pas­ture lands.

“We’re com­mit­ted to black-footed fer­ret re­cov­ery in a funny round­about way, but first we have to fo­cus on the black-tailed prairie dog pop­u­la­tion and distri­bu­tion ob­jec­tives that were out­lined in that man­age­ment plan,” she said. “Grass­lands Na­tional Park also has a multi-species ac­tion plan and we col­lab­o­rate with a lot of part­ners, both in Canada and the United States. So we switched our fo­cus to black-tailed prairie dog with the hope that we can even­tu­ally cir­cle back to con­sid­er­ing re­leas­ing fer­rets again, but we have to make sure that all of those fac­tors are looked af­ter be­fore we try it again.”

The black-tailed prairie dog’s sta­tus in the Species at Risk Act has been in­creased from spe­cial con­cern to threat­ened due to in­creas­ing threats such as drought and syl­vatic plague. This rec­om­men­da­tion was made by the Com­mit­tee on the Sta­tus of En­dan­gered Wildlife in Canada (COSEWIC), and Parks Canada is pre­par­ing a re­cov­ery strat­egy for prairie dogs, which must be com­pleted by 2020. This is done in col­lab­o­ra­tion with species ex­perts, in­clud­ing the Cal­gary Zoo, con­ser­va­tion bi­ol­o­gists, cli­mate change ecol­o­gists, park man­agers and lo­cal ranch­ers.

“The in­tent of the process is to as­sess threats to prairie dog sur­vival, es­ti­mate the prob­a­bil­ity of per­sis­tence of the species in light of a chang­ing cli­mate, and iden­tify op­tions avail­able for the re­cov­ery of black-tailed prairie dog in Canada,” she noted.

The fea­si­bil­ity of any fu­ture re­leases of black­footed fer­rets in Grass­lands Na­tional Park will there­fore de­pend on the out­come of th­ese ef­forts to cre­ate a healthy and suf­fi­cient black-tailed prairie dog pop­u­la­tion.

“It re­mains to be seen,” she said. “The prairie dog re­cov­ery strat­egy and sub­se­quent ac­tion plan will di­rectly in­flu­ence the fea­si­bil­ity of re­cov­ery for black-footed fer­ret. We have to make in­formed, ev­i­dence based, re­spon­si­ble de­ci­sions on both. It is a bal­anc­ing act that we take very se­ri­ously.”

For Clif­ford th­ese on­go­ing ef­forts to give fu­ture vis­i­tors to Grass­lands Na­tional Park an op­por­tu­nity to again hear the chat­ter of black-footed fer­rets will hope­fully serve as an im­por­tant re­minder to pro­tect species and their habi­tat be­fore it is too late.

“Once they’re gone, bring­ing them back can be ex­cep­tion­ally dif­fi­cult,” she said. “That’s why con­ser­va­tion­ists work as they do ev­ery day in the hopes that you never get to that point. “I think some peo­ple also have the mis­con­cep­tion that be­cause we’re suc­cess­fully breed­ing them in cap­tiv­ity, then re­leas­ing them into the wild means that they’re just go­ing to be a suc­cess story. It’s not. Liv­ing in cap­tiv­ity ver­sus liv­ing in the mid­dle of Grass­lands Na­tional Park is some­thing very dif­fer­ent.”

Photo by Paul Knaga, Parks Canada

A black-footed fer­ret sits in the en­trance to a bur­row.

Photo by Paul Boyce

A black-tailed prairie dog dis­plays jump-yip be­hav­iour on a bur­row by stand­ing up on its haunches and lean­ing back its head while mak­ing a call. Prairie dogs are the main food source of black-footed fer­rets.

Photo by Laura Gar­diner

Black-footed fer­rets peer out of their bur­row.

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