Solutions
Hello! Welcome to the Hypotheses & Solutions section of our website. This area will be managed by Alexandra Sutton, and will be the base post for all hypotheses, problem descriptions & discussions, and suggested solutions to the issues facing the Fossil Rim waterbuck herd. In order to make all the ideas clear and easy for all team members to read, please adhere to the following format when posting a hypothesis:
If the major contributing factor in waterbuck calf survivability is ____________, then we may be able to mitigate/manage the problem by _______________________________________________________________________.
General Notes on the Solution:
Possible Challenges/Limitations of the Solution:
If the major contributing factor in waterbuck calf survivability is temperature, then we may be able to mitigate/manage the problem by providing more storm shelters.
General Notes on the Solution: Shelters may be invaded by gemsbok.
Possible Challenges/Limitations of the Solution: Shelters are costly.
If the major contributing factor in waterbuck calf survivability is food competition, then we may be able to mitigate/manage the problem by providing widely separated feeding sites for the animals, in order to give the waterbuck more time to feed.
General Notes: Food may still be foraged by the wider-ranging gemsbok and addax.
Limits: Manpower demands may increase, as it may take personnel longer to reach all assigned feeding sites.
If the major contributing factor in waterbuck calf survivability is mother’s condition, then we may be able to mitigate/manage the problem by providing improved nutrition for lactating mothers and supplemental nutrition for calves.
General Notes: Poor condition in mother may result in premature weaning of calves, leading to increased susceptibility to parasites, disease, etc.
Limits: Food and nutrient supplements may be costly and difficult to distribute to individuals.
If the major contributing factor in waterbuck calf survivability is calf size, then we may be able to mitigate/manage the problem by synchronizing births to encourage good nutrition for mid-size calves.
General Notes: If a mid-sized calf goes down during winter, the animal may be captured, taken in for supportive feeding regimens, and returned later to the herd.
Limits: Synchronization and pulling of calves may be very labor-intensive.
If the major contributing factor in waterbuck calf survivability is management wedges, then we may be able to mitigate/manage the problem by focusing management on critical times of year for waterbuck (i.e. dry seasons), and changing attention dependent on other species’ needs within the same pasture.
General Notes: Management wedges: high-need periods during which management can/should tailor extra care to each species.
Limits: Identification of wedges may be difficult; overlap is possible between species. How can all species’ needs be met with a limited staff?
If the major contributing factor in waterbuck calf survivability is distribution of food within existing feeding sites, then we may be able to mitigate/manage the problem by spreading pellets in a way such that certain species (i.e. addax & gemsbok) will take extra time to forage.
General Notes: If gemsbok and addax take longer to forage, then waterbuck and deer will have longer periods of undisturbed forage/feeding. Spreading pellets over a wider area may allow more individuals to feed in a shorter period of time.
Limits: Compaction of soil around pellet sites.
If the major contributing factor in waterbuck calf survivability is nutrition of females and medium-sized calves, then we may be able to mitigate/manage the problem by supplementing waterbuck diets separately from other species.
General Notes: An option would be to provide large-animal specific exclosures which would allow only smaller animals to feed. However, male deer might still have access to these exclosures and could keep younger waterbuck away.
Another option would be to feed waterbuck near the “waterbuck shed”. However, because this area is unprotected, other species may gain access, particularly if they learn the location of the site over time.
Limits: Will take longer to feed off-route. Also, it is preferred that all waterbuck come to the feed route daily so that their condition can be monitored. Also, because all species have learned to follow the feed truck, a separate vehicle or feed route would have to be provided for the waterbuck.
If the major contributing factor in waterbuck calf survivability is route bias in favor of specific species, then we may be able to mitigate/manage the problem by changing or varying the feed route.
General Notes: Each species has learned the current route, and altering it may cause confusion, resulting in increased conflict and aggression.
Limits: Communication among personnel about route changes in order to ensure consistency will be necessary.
If the major contributing factor in waterbuck calf survivability is poor feeding due to timidity of individuals, then we may be able to mitigate/manage the problem by having volunteers observe the animals and devise individual nutritional supportive therapies.
General Notes:
Limits: Individuals cannot be approached, but will need to be closely observed. Volunteers must be highly trained. Observation vehicle may alter behavior of animals during feeding. Enticing of animals may be difficult because reward foods are unknown. Identification of individuals may be difficult.
If the major contributing factor in waterbuck calf survivability is lack of individual identification, then we may be able to mitigate/manage the problem by tagging animals.
General Notes: In the past, it has been easiest to tag calves directly after birth.
Limits: Without knowing when a female has conceived, it is difficult to predict birth; therefore, calves may go untagged for some time. It is difficult to “catch up” the whole herd, as some individuals have gone untagged for long periods of time. Also, darting individuals to tag them may be disruptive and labor-intensive.
If the major contributing factor in waterbuck calf survivability is variation in weaning times, then we may be able to mitigate/manage the problem by weaning all calves at four months.
General Notes: Calves should be weaned at four months under optimal nutritional conditions.
Limits: Figuring out optimal nutritional conditions for weaning can be difficult. Synchronizing births would also be difficult and labor-intensive; 2 months’ interaction with an intact male may not result in equal conception of all females.
If the major contributing factor in waterbuck calf survivability is lack of synchronized births, then we may be able to mitigate/manage the problem by putting an intact bull into the pasture and then removing him, running the herd without a bull for 10 months of the year.
General Notes: This is the most common method for birth synchronization in the management of an ungulate herd.
Limits: This means that male calves grow up without “training” by herd bulls.
If the major contributing factor in waterbuck calf survivability is lack of synchronized births, then we may be able to mitigate/manage the problem by swapping out a vasectomized and an intact bull, running the herd with a vasectomized bull for 10 months out of the year.
General Notes: We are not aware of previous cases employing this management strategy for grazing antelopes.
Limits: The vasectomized bull may be an important part of herd structure; when he is removed, herd dynamics may change in unpredictable ways. Females may not accept the new bull. If all females are impregnated, then when the vasectomized bull is returned, he may not have any females to follow, and may direct aggression towards other animals in the pasture.
If the major contributing factor in waterbuck calf survivability is lack of synchronized births, then we may be able to mitigate/manage the problem by adding an intact bull, for two months, to the vasectomized and castrated bulls who are already a part of the herd.
General Notes: Not all females may be impregnated during the 2 months of the intact bull’s presence. Interactions amongst the males will depend on individual disposition, age, and learned behaviors. Males are territorial, and in the wild, each male possesses a separate territory; we would predict that females will move easily between males, but the castrated bull appears to lead females to food troughs and chases off competing male deer. Females who are not impregnated during optimal 2 month period may be in poor condition, and may need to rest for a year anyway; therefore, it might not be disadvantageous for some females to remain unimpregnated.
Limits: The intact bull must be trained to respond to an attractor in order to call him into a capture pen. Darting the intact male to remove him from the pasture may be disruptive.
If the major contributing factor in waterbuck calf survivability is amount of precipitation and the subsequent growth of native grasses, then we may be able to mitigate/manage the problem by cultivating native grasses within the pasture.
General Notes: In this year, we had significant rains, which led to increased growth of native grasses. This, in turn, may have led to improved maternal health and subsequent improvements in health of calves. Pastures are generally unmanaged; they are occasionally treated or tilled, but otherwise go undisturbed. Although the amount of precipitation cannot be affected in any way, perhaps careful cultivation of native grasses would be a good solution.
Limits: Not much can be done to cultivate pastures because they are utilised by animals at all times for grazing, browsing, etc. Therefore, protection and cultivation would be difficult. In addition, cultivation could be costly in manpower and capital, and determination of which grasses constituted a “native” blend would be difficult.
If the major contributing factor in waterbuck calf survivability is ensuring that the calves feed on the pellets in the winter, then we may be able to mitigate/manage the problem by feeding all of the animals normally, but providing the water buck with an extra feeding soon after the other animals have completed eating.
Notes: If the other animals are competing with the Waterbuck and Waterbuck calves for pellets, then perhaps waiting for those competitive species to become satiated will allow the Waterbuck to access the pellets without competition. One way to test this would be to feed all of the animals normally, but then do a second pellet feeding. The time between the first and second feeding can be determined experimentally, but it should be based on the amount of time it takes for the other species to become satiated.
Limitations: May be difficult to experimentally determine the appropriate time between feedings.
If the problem is foxes hunting calves, then we might be able to turn up their noses in disgust