alexa Dynamics of an Insularized and Compressed Impala Population: Rainfall, Temperature and Density Influences
Agri and Aquaculture

Agri and Aquaculture

Poultry, Fisheries & Wildlife Sciences

Author(s): Joseph O Ogutu, Erustus Kanga, HansPeter Piepho

Abstract Share this page

Understanding the relative contributions of different life history stages to changes in population abundance is basic to understanding population dynamics and effective management and conservation of large herbivores. We examined temporal variation in natality, recruitment and mortality rates and sex ratio in a compressed and insularized impala population monitored daily for 211 months (17.6 years), spanning June 1994-December 2011. We related the rates to contemporaneous variation in immediate and cumulative past rainfall, temperature and prior abundance. Over the course of this 17.6-year period, the population size fluctuated between 22 and 52 individuals. A total of 213 births, mortality of 96 lambs, 33 males and 58 females; recruitment of 55 juveniles into the female category and 40 juveniles into the male category were recorded. Natural mortality averaged 2.3% of the population annually with lambs contributing 52.3%, males 26.6% and females 21.2%. Lamb mortality was highest in dry months, implicating food scarcity, but female mortality peaked in the wettest months and in hot, wet seasons, suggesting increased susceptibility to diseases and pathogens in hot, damp weather conditions. Male, female and overall population mortality rates were positively correlated with prior abundance, implicating negative density feedbacks on population growth. Births were aseasonal and were surprisingly negatively correlated with rainfall around the time of conception and during wet phases of a regional 5-year rainfall cycle. This implies, quite surprisingly, that high rainfall depressed reproductive success in impalas. Juvenile recruitment increased with increasing 5-month running mean of monthly rainfall but declined (i) at excessively high values of annual rainfall, (ii) with increasing prior density and (iii) in hot, dry seasons. This implicates heightened competition for limiting resources and nutritional stress at high density, increased vulnerability to diseases and pathogens at high rainfall and adverse consequences of habitat desiccation and reduced activity levels at high ambient temperatures.

This article was published in The Open Ecology Journal and referenced in Poultry, Fisheries & Wildlife Sciences

Relevant Expert PPTs

Relevant Speaker PPTs

Recommended Conferences

Relevant Topics

Peer Reviewed Journals
 
Make the best use of Scientific Research and information from our 700 + peer reviewed, Open Access Journals
International Conferences 2017-18
 
Meet Inspiring Speakers and Experts at our 3000+ Global Annual Meetings

Contact Us

Agri, Food, Aqua and Veterinary Science Journals

Dr. Krish

agrifoodaquavet@omicsonline.com

1-702-714-7001 Extn: 9040

Clinical and Biochemistry Journals

Datta A

clinical_biochem@omicsonline.com

1-702-714-7001Extn: 9037

Business & Management Journals

Ronald

business@omicsonline.com

1-702-714-7001Extn: 9042

Chemical Engineering and Chemistry Journals

Gabriel Shaw

chemicaleng_chemistry@omicsonline.com

1-702-714-7001 Extn: 9040

Earth & Environmental Sciences

Katie Wilson

environmentalsci@omicsonline.com

1-702-714-7001Extn: 9042

Engineering Journals

James Franklin

engineering@omicsonline.com

1-702-714-7001Extn: 9042

General Science and Health care Journals

Andrea Jason

generalsci_healthcare@omicsonline.com

1-702-714-7001Extn: 9043

Genetics and Molecular Biology Journals

Anna Melissa

genetics_molbio@omicsonline.com

1-702-714-7001 Extn: 9006

Immunology & Microbiology Journals

David Gorantl

immuno_microbio@omicsonline.com

1-702-714-7001Extn: 9014

Informatics Journals

Stephanie Skinner

omics@omicsonline.com

1-702-714-7001Extn: 9039

Material Sciences Journals

Rachle Green

materialsci@omicsonline.com

1-702-714-7001Extn: 9039

Mathematics and Physics Journals

Jim Willison

mathematics_physics@omicsonline.com

1-702-714-7001 Extn: 9042

Medical Journals

Nimmi Anna

medical@omicsonline.com

1-702-714-7001 Extn: 9038

Neuroscience & Psychology Journals

Nathan T

neuro_psychology@omicsonline.com

1-702-714-7001Extn: 9041

Pharmaceutical Sciences Journals

John Behannon

pharma@omicsonline.com

1-702-714-7001Extn: 9007

Social & Political Science Journals

Steve Harry

social_politicalsci@omicsonline.com

1-702-714-7001 Extn: 9042

 
© 2008-2017 OMICS International - Open Access Publisher. Best viewed in Mozilla Firefox | Google Chrome | Above IE 7.0 version