Parentage analysis in a managed free ranging population of southern white rhinoceros : genetic diversity, pedigrees and management

Small populations are vulnerable to the consequences of breeding within closed groups as the loss of genetic variability can lead to inbreeding depression. Here, we use microsatellite genotypes to assess variability and parentage within a small, managed population of southern white rhinoceros in northern Namibia. Tissue samples gathered from either a modified biopsy darting technique or ear notches allowed us to obtain genotypic data for all individuals in the population. As expected for this species, genetic variability in the population was relatively low (overall H obs 0.45). In combination with detailed management records for the period 1993–2009, we were able to assign both parents for all 23 offspring. Only one calf of seven in the F2 generation arose from father–daughter inbreeding within the population. Our analysis revealed that paternity was initially dominated by a single founder bull siring 10 of 13 calves over 9 years; paradoxically, the other founder bull was selected for removal based on observations suggesting he was behaviourally dominant and therefore the likely sire of most calves. We also found that young introduced bulls were breeding successfully within 6 months of their arrival, well before having established their home ranges. We argue that in order to optimally manage and conserve the southern African white rhinoceros meta-population it is essential to have accurate pedigree information and genetic data for all individuals in the numerous small populations that are key to the survival of the species.Ongava Research Centre is funded by charitable donations from the Namibian Wildlife Conservation Trust (UK), West Midlands Safari Park (UK) and the Directors of Ongava Game Reserve.http://link.springer.com/journal/10592hb201

Lions at the Gates: Trans-disciplinary Design of an Early Warning System to Improve Human-Lion Coexistence

Across Africa, lions (Panthera leo) are heavily persecuted in anthropogenic landscapes. Trans-disciplinary research and virtual boundaries (geofences) programmed into GPS-tracking transmitters offer new opportunities to improve coexistence. During a 24-month pilot study (2016–2018), we alerted communities about approaching lions, issuing 1,017 alerts to four villages and 19 cattle posts. Alerts reflected geofence breaches of nine lions (2,941 monitoring days) moving between Botswana's Okavango Delta and adjacent agro-pastoral communities. Daily alert system costs per lion were US$18.54, or$5,460.24 per GPS deployment (n = 13). Alert-responsive livestock owners mainly responded by night-kraaling of cattle (68.9%), significantly reducing their losses (by $124.61 annually), whereas losses of control group and non-responsive livestock owners remained high ($317.93 annually). Community satisfaction with alerts (91.8%) was higher than for compensation of losses (24.3%). Study lions spent 26.3% of time monitored in geofenced community areas, but accounted for 31.0% of conflict. Manual alert distribution proved challenging, static geofences did not appropriately reflect human safety or the environment's strong seasonality that influenced cattle predation risk, and tracking units with on-board alert functions often failed or under-recorded geofence breaches by 27.9%. These insufficiencies prompted the design of a versatile and autonomous lion alert platform with automated, dynamic geofencing. We co-designed this prototype platform with community input, thereby incorporating user feedback. We outline a flexible approach that recognizes conflict complexity and user community heterogeneity. Here, we describe the evolution of an innovative Information and Communication Technologies-based (ICT) alert system that enables instant data processing and community participation through interactive interfaces on different devices. We highlight the importance of a trans-disciplinary co-design and development process focussing on community engagement while synthesizing expertise from ethnography, ecology, and socio-informatics. We discuss the bio-geographic, social, and technological variables that influence alert system efficacy and outline opportunities for wider application in promoting coexistence and conservation

Spatial patterns of large African cats : a large-scale study on density, home range size, and home range overlap of lions Panthera leo and leopards Panthera pardus

SUPPORTING INFORMATION : APPENDIX S1. Site information. APPENDIX S2. Intuitive explanation of the autocorrelated kernel density estimator. APPENDIX S3. Sources of density data. APPENDIX S4. Mathematical modifications of Jetz et al.’s (2014) overlap equation. APPENDIX S5. Lion pride size data.1. Spatial patterns of and competition for resources by territorial carnivores are typically explained by two hypotheses: 1) the territorial defence hypothesis and 2) the searching efficiency hypothesis. 2. According to the territorial defence hypothesis, when food resources are abundant, carnivore densities will be high and home ranges small. In addition, carnivores can maximise their necessary energy intake with minimal territorial defence. At medium resource levels, larger ranges will be needed, and it will become more economically beneficial to defend resources against a lower density of competitors. At low resource levels, carnivore densities will be low and home ranges large, but resources will be too scarce to make it beneficial to defend such large territories. Thus, home range overlap will be minimal at intermediate carnivore densities. 3. According to the searching efficiency hypothesis, there is a cost to knowing a home range. Larger areas are harder to learn and easier to forget, so carnivores constantly need to keep their cognitive map updated by regularly revisiting parts of their home ranges. Consequently, when resources are scarce, carnivores require larger home ranges to acquire sufficient food. These larger home ranges lead to more overlap among individuals’ ranges, so that overlap in home ranges is largest when food availability is the lowest. Since conspecific density is low when food availability is low, this hypothesis predicts that overlap is largest when densities are the lowest. 4. We measured home range overlap and used a novel method to compare intraspecific home range overlaps for lions Panthera leo (n = 149) and leopards Panthera pardus (n = 111) in Africa. We estimated home range sizes from telemetry location data and gathered carnivore density data from the literature. 5. Our results did not support the territorial defence hypothesis for either species. Lion prides increased their home range overlap at conspecific lower densities whereas leopards did not. Lion pride changes in overlap were primarily due to increases in group size at lower densities. By contrast, the unique dispersal strategies of leopards led to reduced overlap at lower densities. However, when human-caused mortality was higher, leopards increased their home range overlap. Although lions and leopards are territorial, their territorial behaviour was less important than the acquisition of food in determining their space use. Such information is crucial for the future conservation of these two iconic African carnivores.The Natural Sciences and Engineering Research Council of Canada and a Hugh Kelly Fellowship from Rhodes University, Grahamstown, SA.https://onlinelibrary.wiley.com/journal/13652907am2024Centre for Wildlife ManagementMammal Research InstituteZoology and EntomologySDG-15:Life on lan

Structure and function of a neocortical synapse

Thirty-four years since the small nervous system of the nematode C. elegans was manually reconstructed in the electron microscope (EM)1, ‘high-throughput’ EM techniques now enable the dense reconstruction of neural circuits within increasingly large brain volumes at synaptic resolution2–6. As with C. elegans, however, a key limitation for inferring brain function from neuronal wiring diagrams is that it remains unknown how the structure of a synapse seen in EM relates to its physiological transmission strength. Here, we related structure and function of the same synapses to bridge this gap: we combined paired whole-cell recordings of synaptically connected pyramidal neurons in slices of mouse somatosensory cortex with correlated light microscopy and high-resolution EM of all putative synaptic contacts between the neurons. We discovered a linear relationship between synapse size (postsynaptic density area) and synapse strength (excitatory postsynaptic potential amplitude), which provides an experimental foundation for assigning the actual physiological weights to synaptic connections seen in the EM. Furthermore, quantal analysis revealed that the number of vesicle release sites exceeded the number of anatomical synapses formed by a connection by a factor of at least 2.6, which challenges the current understanding of synaptic release in neocortex and suggests that neocortical synapses operate with multivesicular release, like hippocampal synapses7–11. Thus, neocortical synapses are more complex computational devices and may modulate their strength more flexibly than previously thought, with the corollary that the canonical neocortical microcircuitry possesses significantly higher computational power than estimated by current models

Financial Costs of Large Carnivore Translocations – Accounting for Conservation

<div><p>Human-carnivore conflict continues to present a major conservation challenge around the world. Translocation of large carnivores is widely implemented but remains strongly debated, in part because of a lack of cost transparency. We report detailed translocation costs for three large carnivore species in Namibia and across different translocation scenarios. We consider the effect of various parameters and factors on costs and translocation success. Total translocation cost for 30 individuals in 22 events was $80,681 (US Dollars). Median translocation cost per individual was$2,393, and $2,669 per event. Median cost per cheetah was$2,760 (<i>n</i> = 23), and $2,108 per leopard (<i>n</i> = 6). One hyaena was translocated at a cost of$1,672. Tracking technology was the single biggest cost element (56%), followed by captive holding and feeding. Soft releases, prolonged captivity and orphaned individuals also increased case-specific costs. A substantial proportion (65.4%) of the total translocation cost was successfully recovered from public interest groups. Less than half the translocations were confirmed successes (44.4%, 3 unknown) with a strong species bias. Four leopards (66.7%) were successfully translocated but only eight of the 20 cheetahs (40.0%) with known outcome met these strict criteria. None of the five habituated cheetahs was translocated successfully, nor was the hyaena. We introduce the concept of Individual Conservation Cost (ICC) and define it as the cost of one successfully translocated individual adjusted by costs of unsuccessful events of the same species. The median ICC for cheetah was $6,898 and$3,140 for leopard. Translocations are costly, but we demonstrate that they are not inherently more expensive than other strategies currently employed in non-lethal carnivore conflict management. We conclude that translocation should be one available option for conserving large carnivores, but needs to be critically evaluated on a case-by-case basis.</p></div

Parentage analysis in a managed free ranging population of southern white rhinoceros: genetic diversity, pedigrees and management. Conservation Genetics 13:811-822 IRCF. 2006. Focus on Conservation: Guatemalan Beaded Lizard (Heloderma horridum charlesboge

Abstract Small populations are vulnerable to the consequences of breeding within closed groups as the loss of genetic variability can lead to inbreeding depression. Here, we use microsatellite genotypes to assess variability and parentage within a small, managed population of southern white rhinoceros in northern Namibia. Tissue samples gathered from either a modified biopsy darting technique or ear notches allowed us to obtain genotypic data for all individuals in the population. As expected for this species, genetic variability in the population was relatively low (overall H obs 0.45). In combination with detailed management records for the period 1993-2009, we were able to assign both parents for all 23 offspring. Only one calf of seven in the F 2 generation arose from father-daughter inbreeding within the population. Our analysis revealed that paternity was initially dominated by a single founder bull siring 10 of 13 calves over 9 years; paradoxically, the other founder bull was selected for removal based on observations suggesting he was behaviourally dominant and therefore the likely sire of most calves. We also found that young introduced bulls were breeding successfully within 6 months of their arrival, well before having established their home ranges. We argue that in order to optimally manage and conserve the southern African white rhinoceros meta-population it is essential to have accurate pedigree information and genetic data for all individuals in the numerous small populations that are key to the survival of the species

Success rates and costs of large carnivore translocations in USD, including estimated Individual Conservation Cost (ICC) for each category.

<p>A – Total cost for translocation study by category. B – Total cost without post-release tracking technology and expenses. *Individuals with unknown translocation outcome (<i>n</i> = 3) were removed from success rate calculations. An Individual Conservation Cost (ICC) is defined as the successful translocation in each category and accounts for failed attempts. Cost per ICC was estimated as the median cost/translocation success in each category, except for events because cheetah group releases resulted in both successful and unsuccessful translocations.</p

Biological and technical details for 30 translocated large carnivores, 2008–2012.

<p>Aju indicates cheetah; Pp indicates leopard; Hbr indicates brown hyaena. Year is year of release. Indiscriminate captures include animals that predated on valuable game species. Semi-habituated  =  tolerance of human proximity only during feeding events before release. Habituated  =  tolerance of human proximity beyond feeding events before release. Group releases represent coalitions and not presence of offspring. Observed courtship  =  males seen in presence of wild females and displaying obvious courtship behaviour.</p>a<p>translocated with 2 dependant offspring.</p>b<p>translocated with 3 dependant offspring.</p

Analysis of large carnivore translocation costs.

<p>Panel A displays the distribution of total cost by category (black bars), demonstrating the impact of tracking technology (grey bars). Panel B compares cost and the amount recuperated from public interest groups in each category.</p

Reported cost per carnivore (in USD) of different non-lethal carnivore conflict management options.

<p>All values are rounded to the nearest US$. For comparison, all values are reported as means. We consulted a total of 57 publications that mentioned costs of non-lethal mitigation strategies. Here we report only those studies that measured cost using similar methodologies to our study.</p>a<p>Where necessary, original values where converted from other currencies into USD on 16 April 2013.</p>b<p>Annual cost extrapolated from monthly cost.</p