To evaluate conservation interventions, it is necessary to obtain reliable population trends for short (<10 years) time scales. Telemetry can be used to estimate short-term survival rates and is a common tool for assessing population trends, but it has limitations and can be biased toward specific behavioral traits of tagged individuals. Encounter rates calculated from transects can be useful for assessing changes across multiple species, but they can have large confidence intervals and be affected by variations in survey conditions. The decline of African vultures has been well-documented, but understanding of recent trends is lacking. To examine population trends, we used survival estimates from telemetry data collected over 6 years (primarily for white-backed vultures [Gyps africanus]) and transect counts conducted over 8 years (for 7 scavenging raptors) in 3 large protected areas in Tanzania. Population trends were estimated using survival analysis combined with the Leslie Lefkovitch matrix model from the telemetry data and using Bayesian mixed effects generalized linear regression models from the transect data. Both methods showed significant declines for white-backed vultures in Ruaha and Nyerere National Parks. Only telemetry estimates suggested significant declines in Katavi National Park. Encounter rates calculated from transects also showed declines in Nyerere National Park for lappet-faced vultures (38% annual declines) and Bateleurs (18%) and in Ruaha National Park for white-headed vultures (Trigonoceps occipitalis) (19%). Mortality rates recorded and inferred from telemetry suggested that poisoning is prevalent. However, only 6 mortalities of the 26 presumed mortalities were confirmed to be caused by poisoning, highlighting the challenges of determining the cause of death when working across large landscapes. Despite declines, our data provide evidence that southern Tanzania has higher current encounter rates of African vultures than elsewhere in East Africa. Preventing further declines will depend greatly on mitigating poisoning. Based on our results, we suggest that the use of multiple techniques improves understanding of population trends over the short term.

Download full-text PDF

Source
http://dx.doi.org/10.1111/cobi.14146DOI Listing

Publication Analysis

Top Keywords

population trends
8
combining transect
4
transect counts
4
counts telemetry
4
telemetry data
4
data determine
4
determine short-term
4
short-term population
4
trends globally
4
globally threatened
4

Similar Publications

Background: Although several studies have examined the Kidney Disease Quality of Life (KDQOL) in patients with chronic kidney disease (CKD), the factors associated with kidney-related symptoms have not been fully explored.

Methods: This nationwide multicenter cohort study enrolled 2248 patients. To identify the factors associated with each item or the three KDQOL domains, such as burden of kidney disease, symptoms/problems of kidney disease, and impact of kidney disease on daily life, multiple regression analysis was performed using baseline data.

View Article and Find Full Text PDF

ObjectiveCOVID-19 affected health care globally. The aim of this study was to investigate the impact of COVID-19 on both public and private emergency departments (EDs).MethodsThis was a retrospective cohort study of ED presentations made to three private and two public hospital EDs located in one region in Queensland.

View Article and Find Full Text PDF

Infective endocarditis: a growing threat despite medical progress. A look at trends in Spain.

Rev Esp Cardiol (Engl Ed)

January 2025

Unidad de Salud Pública, Prevención y Promoción de la Salud, Área de Gestión Sanitaria Sur de Sevilla, Sevilla, España.

Introduction And Objectives: Infective endocarditis (IE) is a serious public health problem both in Spain and worldwide. This study aimed to analyze the trends in the incidence of IE in Spain from 1992 to 2021.

Methods: We used IE incidence data from the Global Health Data Exchange and population data from the Spanish National Statistics Institute to analyze changes in age-standardized incidence rates.

View Article and Find Full Text PDF

This study analyzes U.S. diabetes mortality trends from 1968 to 2019 using CDC WONDER data.

View Article and Find Full Text PDF

Syphilis-positive and false-positive trends among US blood donors, 2013-2023.

Transfusion

January 2025

Infectious Disease Consultant, North Potomac, Maryland, USA.

Background: US blood donors are tested for syphilis because the bacterial agent is transfusion transmissible. Here we describe trends over an 11-year period of donations positive for recent and past syphilis infections, and donations classified as syphilis false positive (FP).

Methods: Data from January 1, 2013, to December 31, 2023 (11 years) were compiled for all American Red Cross blood donations to evaluate demographics/characteristics and longitudinal trends in donors testing syphilis reactive/positive.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!