Insights on Avian Life History and Physiological Traits in Central Africa: Ant-following Species have Young-dominated age ratios in Secondary Forest

Panagiotis Nikolaou ^1,2,3,4* Billi A Krochuk ^2,5 Patricia F Rodrigues ^1,2,6 Kristin E. Brzeski ^2,7 Christopher M. Tonra ⁸ Jacob C. Cooper ⁹ Jared D. Wolfe ^2,7 Luke L. Powell ^1,2,3,4 Silvestre Esteban Malanza ^10,2 Susana Lin Mufumu ^10,2

• ¹ Centro de Investigacao em Biodiversidade e Recursos Geneticos (CIBIO-InBIO), Vairão, Portugal
• ² Biodiversity Initiative, Houston St, New York, United States
• ³ BIOPOLIS Program in Genomics, Biodiversity and Land Planning, CIBIO, Campus de Vairão, 4485-661 Vairão, Portugal
• ⁴ College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, Scotland, United Kingdom
• ⁵ Biodiversity Research Institute, 276 Canco Road, Portland, Maine, 04103, United States
• ⁶ Louisiana State University, Baton Rouge, Louisiana, United States
• ⁷ School of Forest Resource and Environmental Science, Michigan Technological University, Houghton, Michigan, United States
• ⁸ School of Environment and Natural Resources, College of Food, Agricultural, and Environmental Sciences, The Ohio State University, Columbus, Ohio, United States
• ⁹ KU Biodiversity Institute & Natural History Museum, University of Kansas, Lawrence, Kansas, United States
• ¹⁰ National University of Equatorial Guinea, Malabo, Equatorial Guinea

The Congo Basin rainforest and adjacent Lower Guinea Forest constitute the second largest tract of lowland tropical rainforest in the world. As with the rest of the continent, human population is increasing rapidly and forest degradation isn ubiquitous. The Afrotropics contain the Earth's second largest rainforest, the Congo (or Lower Guinea Forest), where human population is increasing rapidly and forest degradation is ubiquitous. Forest degradation through logging has pervasive negative effects on ecosystems, but selective logging is considered less destructive impactful than clearcutting. Recent research in Afrotropical forest shows When disturbance occurs in the Afrotropics, recent research shows that certain avian species and guilds are most affected by selective logging (e.g., specialist insectivores such as followers of Dorylus driver ants); however, the mechanisms behind these patterns are poorly known. In an eight-year long-term mist-netting effort in Equatorial Guinea, we worked eight field seasons and caught 1193 birds in primary forest and high-grade selectively logged secondary forest to determine the effect of disturbance on six demographic and physiological measures on birds. We compared five life history and population traits for ten insectivorous species: proportion of breeding and molting birds, molt-breeding overlap, bird age, and a body mass index. We also analyzed the concentrations of the stress hormone feather corticosterone (fCORT) in five species. All three strict ant-following species (Alethe castanea, Chamaetylas poliocephala, Neocossyphus poensis), and the Muscicapid thrush robin Sheppardia cyornithopsis had a higher proportion of first year birds in secondary forest. Furthermore, two ant-followers, A. castanea and C. poliocephala, had a higher proportion of individuals molting in primary forest. Finally, only Illadopsis cleaveri had higher body condition in secondary forest. We found no differences in breeding status, molt-breeding overlap or fCORT between forest types. Using a long-term mistnetting effort, we use measures taken from birds-in-the-hand to go beyond insights from point counts alone; we gain valuable insights into the demography and physiology of Afrotropical birds occupying variably disturbed lowland tropical rainforest.bird demography and physiology as Afrotropical Forest is disturbed.