Showing posts with label recruitment. Show all posts
Showing posts with label recruitment. Show all posts

Wednesday, August 29, 2012

A Fostering First!

This year marks a first in red wolf pup fostering in the Red Wolf Recovery Program. But first, what is fostering?

Fostering is when pups from one litter (typically a captive-born litter) are placed in another litter (typically a wild-born litter) to be raised by parents that are not their own. Fostering pups from a captive litter to a wild litter has been a successful tool used by the Red Wolf Recovery Program as a means to increase the numbers of wild red wolves and enhance the genetic diversity of the wild population.

[Captive-born red wolf pups soon to be fostered into a wild litter. Photo credit: D. Beeland/USFWS]

The Red Wolf Recovery Program first fostered pups into a wild litter in 2002. A pair of two-week old pups born at the North Carolina Zoological Park were placed in a wild wolf den to be raised alongside the wild pups. The fostering was a success, and subsequent fostering efforts have yielded equal success. In fact, no wild red wolf mother has ever been known to reject a fostered pup, and the fostered pups’ survival rates appear to be equal to that of their wild-born “siblings.”

A few stipulations are adhered to when fostering pups, though. First, the pups are ideally no more than two-weeks of age at the time of the fostering. The mother’s maternal instinct is believed to be very strong with pups of this age, which decreases the likelihood of pup rejection. Also, the pups have limited mobility at this age, increasing the likelihood that they will stay in the den and not wander off before the mother returns. Another stipulation is that the captive-born pups should be very close in age to the wild-born pups. This decreases the likelihood of some of the pups out-competing others for food. Lastly, a potential foster mother is usually selected based on her having a relatively low number of pups in her litter, coupled with her proven ability to have successfully raised a litter in previous years. When combined, these conditions increase the likelihood that the mother wolf will be able to successfully raise a couple of extra pups added to her litter.

[Fostered red wolf pups in a den with their new "siblings." Photo credit: D. Beeland/USFWS]

So, what was so special about fostering pups in 2012? Well, this year we fostered two captive-born pups into a litter of three wild-born pups that were born to a mother that was once a captive-born fostered pup! In addition, two other wild red wolves (1 male and 1 female) that were once fostered pups had litters of their own this year!

These are a few of the great examples of how successful fostering pups has been through the years for the Red Wolf Recovery Program. -- Ryan

Friday, July 6, 2012

2012 Pup Season... What a success!

Another breeding season has come and gone in red wolf country. The final tally for wild-born red wolf pups was 40 in nine litters. An additional 41 pups from nine litters were born in Red Wolf Species Survival Plan (RWSSP) facilities across the country. All in all it was a pretty good year of pup production for the Red Wolf Recovery Program!

Monday, April 16, 2012

Gunshot Mortality of Red Wolves

The following blog entry about gunshot mortality of red wolves is excerpted from a chapter in the forthcoming book entitled "The Secret World of Red Wolves: A True Story of North America's other Wolf," by T. DeLene Beeland (University of North Carolina Press, coming early 2013), and is reproduced here with the permission of the author. CAUTION: Images included in this blog may be disturbing to some readers.

Since 2004, an average of 6.5 red wolves die each year from gunshot wounds. Studying years past, it is easy to see an emerging trend: between 1987 and 2003, twenty-eight red wolves were shot. But between 2004 and 2010, the number of gunshot red wolves rose to forty-five confirmed cases. By the end of 2011, the total number of gunshot wolves have increased to fifty-two. In other words, 65 percent of the known gunshot red wolves occurred in the most recent eight years of the twenty-five-year-long program. Six were shot in 2004; five were shot in 2005; four were shot in 2006; nine were shot in 2007; six were shot in 2008 (plus two confirmed poisonings); seven were shot in 2009; eight were shot in 2010; and another seven were shot in 2011. The killings are akin to death by a thousand slices to the population as a whole.

[Number of red wolves killed by gunshot, 1987-2011]


Unfortunately, the breeders are hit disproportionately according to the red wolf team. Since 2004, the biologists calculate that breeding individuals compose 73 percent of the wolves shot illegally. Losing a breeder busts up packs which in turn leads to single wolves becoming vulnerable to intraspecific aggression. The loss of a breeder can also equate to pups or pre-dispersing age juveniles losing parental protection. Most worrisome to the red wolf field team, losing a breeder puts that pack's territory at risk: they had too often observed fertile coyotes move into territories shortly after the disruption of a breeding pair.

[Red Wolf on left; Coyote on right. Photo credit: red wolf, Crawford/USFWS; coyote, USFWS]

A study published in 2011 in PLoS-ONE by Dennis Murray and Amanda Sparkman from Trent University, and Lisette Waits from the University of Idaho, was the first to address the issue of how anthropogenic killings affect the red wolf population. The researchers tested two ecological theories: one proposed that human-caused killings have an “additive” effect which reduces a population’s overall survival rates, while the second proposed that human-caused killings trigger a “compensatory” effect which makes up for unnatural losses, possibly by reducing the natural mortality rate which then balances the overall survival rate.

The researchers divided the red wolf population growth into two major time periods, from 1990-1998 and 1999 to 2006, and classified the first timeframe as having a low population density (when the reintroduced population was still growing) and the second as having a high population density (when the recovery area began to approach being full). They found that at low population densities, the red wolf population experienced a strong additive effect from human-caused killings. But at higher densities, they found evidence for both additive and compensatory effects. They hypothesized that as stable red wolf packs dissolved due to human-caused killings, it freed the surplus breeding-age red wolves to either begin breeding with the surviving mate, or to take over the territory of a dissolved pack and form an entirely new breeding pair...

[Red Wolf. Photo credit: Nordsven/USFWS]

...A second study with insight to how anthropogenic killings affects red wolves took the form of a dissertation under the tutelage of Lisette Waits, a wildlife geneticist at the University of Idaho. (Waits is also the person responsible for testing the blood samples of the red wolves for the genetic markers that qualify them as true red wolves.) Waits and her then-student, Justin Bohling, examined characteristics of individual red wolves that were involved in hybridization events verified to have occurred. They discovered that the majority of the red wolves that crossed with coyotes did so under similar circumstances.

“A high proportion of these hybridization events were occurring after the disruption of a stable breeding pair,” Waits said. “Particularly, it’s been a problem associated with gunshot mortality during the hunting season, and the hunting season precedes the breeding season.”

[Red Wolf. Photo credit: Nordsven/USFWS]

Waits and Bohling pored over breeding records and the individual life histories of red wolves known to have been involved in hybridization events between 2001 and 2009. They studied twenty-one hybrid litters and ninety-one red wolf litters and examined them for correlations with age and breeding experience, if the animal had a mixed red wolf/coyote ancestry, birthing location within the red wolf recovery area, and whether pack disruption was a factor leading to future interspecies crosses. They found that the hybrid litters clustered toward the western side of the Albemarle peninsula, and that the average age of female breeders who birthed hybrid litters was slightly less, at 4.2 years old, than the average age of female breeders who birthed red wolf litters at about 5.4 years old. But perhaps the most interesting result was that thirteen of the twenty-one [62%] hybrid litters were produced after a stable breeding pair of red wolves were broken apart. Seven of these dissolutions [54%] occurred because a breeder had been shot and killed, while two more involved the death of a breeder from poison or trap injuries—in all, nine of the thirteen [69%] broken pairs were attributed to human actions.

[Percent mortality of red wolves, 1999-2011]

In the eyes of the red wolf field team, Murray's study described the past but they felt the spike in gunshot mortality they had observed since 2004 significantly altered the possibility that the compensatory effects would continue to balance the additive effects. They also countered that the study failed to capture the level of management effort that the team had to invest in fostering new red wolf pairs each time a pair dissolved; not to mention their efforts to trap, sterilize and monitor new coyotes that moved into a former pack's territory. They had increased their management effort in step with the uptick in illegal killings since 2004 and they felt that Murray's conclusions, that the additive and compensatory effects would continue to balance each other out at high population densities, omitted how an increased rate of killings stretched their management workload to the point of bursting. They believed Waits and Bohling's study accurately described the scenarios they had witnessed time and time again when a pack dissolved largely due to human-caused reasons and hybridization often followed.

The red wolf recovery program hinges upon successful field work, and in order to grow the population the biologists believe their breeders need to maintain stable territories and stable packs that regularly produce puppies each spring. But the illegal killings, whether accidental or not, are possibly curtailing the program’s success including the field staff’s ability to control hybridization issues by using coyote sterilization as a management tool.

The U.S. Fish and Wildlife Service is investigating the suspected illegal take of several red wolves found dead in the Red Wolf Recovery Area (Dare, Hyde, Tyrrell, Washington, and Beaufort Counties, NC). Contributions from various organizations and individuals have resulted in a reward of up to $15,000 for information directly leading to an arrest, a criminal conviction, a civil penalty assessment, or forfeiture of property on the subject or subjects responsible for the suspected unlawful take of these red wolves. The red wolf is protected under the Endangered Species Act. The maximum criminal penalties for the unlawful taking of a red wolf are one year imprisonment and $100,000 fine per individual. Anyone with information on the deaths of red wolves is urged to contact Special Agent Sandra Allred at (919) 856-4786 or North Carolina Wildlife Resources Commission Officer Robert Wayne at (252) 216-8225.

Tuesday, June 14, 2011

2011: A Good Year for Red Wolf Recruitment

As the 2011 denning season winds down for the Red Wolf Recovery Program, the tally of red wolf pups born in the wild appears to be 46. This was an unexpectedly strong year for recruitment in the wild population. The number of mortalities of breeding wolves in recent years presented a challenge in optimism going into this year's denning season. Fortunately, 11 pairs of breeding wolves, including seven newly formed pairs and first time breeders, gave us a lot to be optimistic about.

[Red wolf pups. Photo credit: R. Nordsven/USFWS]