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Editor's Choice: Breeding biology of Hawaiian birds and Uruguayan savanna avian assemblages

By Philip Stouffer, Editor

Photo: A foraging 'Akeke'e. By Lucas Behnke
The editor of the The Condor: Ornithological Applications highlights two recent publications. The first explores the breeding biology of two endangered Hawaiian forest birds. The second describes the structure of avian assemblages in grasslands associated with agriculture in the Uruguayan savanna ecoregion.
First Study of Breeding Biology of Two Endangered Hawaiian Honeycreepers
(January 7, 2015, The Condor: Ornithological Applications)—A new open-access article in The Condor: Ornithological Applications presents the first comprehensive study of the breeding biology of two endangered Hawaiian honeycreepers, the ‘Akikiki (Oreomystis bairdi) and ‘Akeke‘e (Loxops caeruleirostris). Ruby Hammond of Northern Arizona University, along with Lisa Crampton and Jeffrey Foster, monitored populations of both birds in the remote central to their mountains of Kauai during the breeding seasons of June 2012 and 2013, investigating both their basic breeding biology and whether nest failure could be a factor contributing to their continuing population decline. They found that the breeding behavior of ‘Akikiki and ‘Akeke‘e is similar overall to that of other honeycreepers, including social monogamy, long nesting cycles, and a strong preference for nesting in ‘ōhi‘a trees. Surprisingly, estimates of nesting success for ‘Akikiki and ‘Akeke‘e were over 25% higher than the overall success rate of other Hawaiian forest birds in past studies, with no single cause dominating nest failures. Because these species’ habitat is difficult to access and funding is limited, the study’s authors suggest that future research focus on post-fledging, juvenile, and adult survival, rather than nest failure, as possible contributors to their decline.

Ruby L. Hammond, Lisa H. Crampton, and Jeffrey T. Foster (2015) Breeding biology of two endangered forest birds on the island of Kauai, Hawaii. The Condor: February 2015, Vol. 117, No. 1, pp. 31-40.

The full article is available at http://www.aoucospub.../CONDOR-14-75.1

Cattle Ranching Supports Greater Bird Diversity than Soybeans in Uruguay
(January 14, 2015, The Condor: Ornithological Applications)—Land used for cattle ranching supports larger and more diverse bird communities than soybean fields in the Uruguayan grassland region, according to a new open-access study published this week in The Condor: Ornithological Applications. Thaiane Weinert da Silva, Graziela Dotta, and Carla Suertegaray Fontana of the Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS) in Brazil spent two years surveying and comparing the birds found on soybean and cattle sites in the grasslands of Uruguay and Brazil. Overall, they found that cattle sites had high species richness than soybean sites and supported more bird species considered representative of southeastern South American grasslands. However, some bird species of conservation interest, such as the Greater Rhea (Rhea americana), were also found in and adjacent to soybean fields, suggesting that more research is necessary to determine exactly how some birds use mixed agricultural landscapes. The message of this study is that when it comes to supporting bird populations, not all types of agriculture are equivalent, and Weinert da Silva and her colleagues recommend that farmers, conservationists, and government agencies in the region come together to discuss how to balance their differing priorities.

Thaiane Weinert da Silva, Graziela Dotta, and Carla Suertegaray Fontana (2015) Structure of avian assemblages in grasslands associated with cattle ranching and soybean agriculture in the Uruguayan savanna ecoregion of Brazil and Uruguay. The Condor: February 2015, Vol. 117, No. 1, pp. 53-63.

The full article is available at http://www.aoucospub.../CONDOR-14-85.1