Wild dogs in the Serengeti ecosystem: what really happened

East, Marion L.; Hofer, Heribert

doi:10.1016/0169-5347(96)88902-6

“…Burrows’ hypothesis postulates that the decline and disappearance of the African wild dog population on the Serengeti plains was a direct result of researcher‐induced disease outbreaks. Despite the resistance of the scientific community at large to accept this hypothesis, the proponents thereof have consistently defended it (Burrows, ; Burrows et al, ; East & Hofer, ; East et al, ). Using a multifaceted approach and data from the same wild dog population, where disease is still prevalent, we found no support for Burrows’ hypothesis.…”

Section: Discussionmentioning

confidence: 99%

“…This led Burrows () to postulate that the stress associated with the immobilization and handling of wild dogs (in the absence of vaccination) for research purposes caused immunosuppression, resulting in the reactivation of a latent form of the rabies virus, thereby causing the death of the entire study population. Despite staunch opposition (see Methods), the hypothesis was vehemently defended by its proponents and the debate remains unresolved (Burrows, ; Burrows et al, ; East & Hofer, ; East et al, ).…”

Section: Introductionmentioning

confidence: 99%

“…Studied since 1964, this population of endangered wild dogs declined and eventually disappeared entirely from the study area in 1991 (Burrows, Hofer, & East, 1994;Ginsberg, Mace, & Albon, 1995). The cause of the wild dogs' decline and eventual demise was extensively debated among scientists at the time (Burrows et al, 1994;Burrows, Hofer, & East, 1995;Creel, Creel, & Monfort, 1997;Devilliers et al, 1995;East & Hofer, 1996;East, Hofer, & Burrows, 1997;Gascoyne et al, 1993;Ginsberg, Alexander, et al, 1995;Ginsberg, Mace, et al, 1995;Woodroffe, 2001). Yet more than 25 years later, consensus has not been reached.…”

mentioning

confidence: 99%

See 1 more Smart Citation

No evidence of handling‐induced mortality in Serengeti's African wild dog population

Jackson

¹

,

Masenga

²

,

Mjingo

³

et al. 2018

Ecology and Evolution

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The disappearance of an endangered African wild dog population from Serengeti National Park (SNP) led to international debate centered around one question: were researchers to blame? The “Burrows' hypothesis” postulated that stress induced by research‐related immobilization and handling reactivated a latent rabies virus, eliminating the population. Insufficient data inhibited hypothesis testing, but since wild dogs persisted alongside SNP and have been studied since 2005, the hypothesis can be tested 25 years after its proposition. To be supported, wild dog immobilization interventions should have resulted in high mortality rates. However, 87.6% of 121 handled wild dogs (2006–2016) survived >12 months post‐handling. Some argued that viral reactivation would necessitate long‐term stress. Following immobilization, 67 animals were captured, transported, and held in a translocation enclosure. Despite the longer‐term stress, 95.5% survived >12 months. Furthermore, the stable number of wild dog packs in the ecosystem over the past decade, and lack of recolonization of SNP, strongly oppose Burrows' hypothesis. Instead, factors such as heightened levels of interspecific competition are likely to have contributed to the wild dog disappearance and subsequent avoidance of the Serengeti plains. Handling and radio telemetry are invaluable when studying elusive endangered species, yielding information pertinent to their conservation and management, and had no effect on Serengeti wild dog survival.

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“…In 1992, Burrows et al suggested that the extinction of wild dogs in the Serengeti was due to the stress caused by invasive research methods. This hypothesis generated controversy (Burrows 1992;Burrows et al 1994;Gascoyne & Laurenson 1994;Burrows et al 1995;Ginsberg et al 1995Ginsberg et al a , 1995Kat & Alexander 1995;de Villiers et al 1995;East 1996;East & Hofer 1996;East et al 1997;Woodroffe et al 1997). To determine the likely cause of extinction, a PVA was conducted with the program VORTEX (Lacy 1993).…”

Section: Introductionmentioning

confidence: 99%

Using Logistic Regression to Analyze the Sensitivity of PVA Models: a Comparison of Methods Based on African Wild Dog Models

Cross¹,

Beissinger²

2001

Conservation Biology

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We used logistic regression as a method of sensitivity analysis for a stochastic population viability analysis model of African wild dogs ( Lycaon pictus ) and compared these results with conventional sensitivity analyses of stochastic and deterministic models. Standardized coefficients from the logistic regression analyses indicated that pup survival explained the most variability in the probability of extinction, regardless of whether or not the model incorporated density dependence. Adult survival and the standard deviation of pup survival were the next most important parameters in density-dependent simulations, whereas the severity and probability of catastrophe were more important during density-independent simulations. The inclusion of density dependence decreased the probability of extinction, but neither the abruptness nor the inclusion of density dependence were important model parameters. Results of both relative sensitivity analyses that altered each parameter by 10% of its range and life-stage-simulation analyses of deterministic matrix models supported the logistic regression results, indicating that pup survival and its variation were more important than other parameters. But both conventional sensitivity analysis of the stochastic model which changed each parameter by 10% of its mean value and elasticity analyses indicated that adult survival was more important than pup survival. We evaluated the advantages and disadvantages of using logistic regression to analyze the sensitivity of stochastic population viability models and conclude that it is a powerful method because it can address interactions among input parameters and can incorporate the range of parameter variability, although the standardized regression coefficients are not comparable between studies. Model structure, method of analysis, and parameter uncertainty affect the conclusions of sensitivity analyses. Therefore, rigorous model exploration and analysis should be conducted to understand model behavior and management implications.Utilización de la Regresión Logística para Analizar la Sensibilidad de Modelos de AVP: una Comparación de Métodos Basados en Modelos de Perros Silvestres Africanos Resumen: Utilizamos la regresión logística como un método de análisis de sensibilidad par a un modelo de análisis de viabilidad poblacional de perros silvestres Africanos ( Lycaon pictus ) y comparamos estos resultados con análisis de sensibilidad convencionales de modelos estocásticos y determinísticos. Coeficientes estandarizados de los análisis de regresión logística indicaron que la supervivencia de cachorros explicaba la mayor variabilidad en la probabilidad de extinción, independientemente de que el modelo incorporara la denso-dependencia. La supervivencia de adultos y la desviación estándar de la supervivencia de cachorros fueron los parámetros que siguieron en importancia en simulaciones de denso-dependencia, mientras que la severidad y la probabilidad de catástrofes fueron más importantes durante simulaciones denso-independientes. La inclu...

show abstract

“…In 1992, Burrows et al suggested that the extinction of wild dogs in the Serengeti was due to the stress caused by invasive research methods. This hypothesis generated controversy ( Burrows 1992; Burrows et al 1994; Gascoyne & Laurenson 1994; Burrows et al 1995; Ginsberg et al 1995 a , 1995 b ; Kat & Alexander 1995; de Villiers et al 1995; East 1996; East & Hofer 1996; East et al 1997; Woodroffe et al 1997). To determine the likely cause of extinction, a PVA was conducted with the program VORTEX ( Lacy 1993).…”

Section: Introductionmentioning

confidence: 99%

Using Logistic Regression to Analyze the Sensitivity of PVA Models: a Comparison of Methods Based on African Wild Dog Models

Cross

¹

,

Beissinger

²

2001

Conservation Biology

View full text Add to dashboard Cite

We used logistic regression as a method of sensitivity analysis for a stochastic population viability analysis model of African wild dogs ( Lycaon pictus ) and compared these results with conventional sensitivity analyses of stochastic and deterministic models. Standardized coefficients from the logistic regression analyses indicated that pup survival explained the most variability in the probability of extinction, regardless of whether or not the model incorporated density dependence. Adult survival and the standard deviation of pup survival were the next most important parameters in density-dependent simulations, whereas the severity and probability of catastrophe were more important during density-independent simulations. The inclusion of density dependence decreased the probability of extinction, but neither the abruptness nor the inclusion of density dependence were important model parameters. Results of both relative sensitivity analyses that altered each parameter by 10% of its range and life-stage-simulation analyses of deterministic matrix models supported the logistic regression results, indicating that pup survival and its variation were more important than other parameters. But both conventional sensitivity analysis of the stochastic model which changed each parameter by 10% of its mean value and elasticity analyses indicated that adult survival was more important than pup survival. We evaluated the advantages and disadvantages of using logistic regression to analyze the sensitivity of stochastic population viability models and conclude that it is a powerful method because it can address interactions among input parameters and can incorporate the range of parameter variability, although the standardized regression coefficients are not comparable between studies. Model structure, method of analysis, and parameter uncertainty affect the conclusions of sensitivity analyses. Therefore, rigorous model exploration and analysis should be conducted to understand model behavior and management implications.Utilización de la Regresión Logística para Analizar la Sensibilidad de Modelos de AVP: una Comparación de Métodos Basados en Modelos de Perros Silvestres Africanos Resumen: Utilizamos la regresión logística como un método de análisis de sensibilidad par a un modelo de análisis de viabilidad poblacional de perros silvestres Africanos ( Lycaon pictus ) y comparamos estos resultados con análisis de sensibilidad convencionales de modelos estocásticos y determinísticos. Coeficientes estandarizados de los análisis de regresión logística indicaron que la supervivencia de cachorros explicaba la mayor variabilidad en la probabilidad de extinción, independientemente de que el modelo incorporara la denso-dependencia. La supervivencia de adultos y la desviación estándar de la supervivencia de cachorros fueron los parámetros que siguieron en importancia en simulaciones de denso-dependencia, mientras que la severidad y la probabilidad de catástrofes fueron más importantes durante simulaciones denso-independientes. La inclu...

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Wild dogs in the Serengeti ecosystem: what really happened

Cited by 5 publications

References 4 publications

No evidence of handling‐induced mortality in Serengeti's African wild dog population

No evidence of handling‐induced mortality in Serengeti's African wild dog population

Using Logistic Regression to Analyze the Sensitivity of PVA Models: a Comparison of Methods Based on African Wild Dog Models

Using Logistic Regression to Analyze the Sensitivity of PVA Models: a Comparison of Methods Based on African Wild Dog Models

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