Realized trophic niche driven by apparent competition: an example with marsupials

Autor(es)

Kuhnen, Vanessa V. ^[1] ; Martinez de Aguiar, Marcus A. ^[2] ; Goncalves, Ana Z. ^[3] ; Setz, Eleonore Z. F. ^[4]

Afiliação do(s) autor(es)

^[1] Univ Estadual Campinas, UNICAMP, Inst Biol, Posgrad Ecol, CP 6109, BR-13083970 Campinas, SP - Brazil

^[2] Univ Estadual Campinas, UNICAMP, Inst Fis Gleb Wataghin, BR-13083859 Campinas, SP - Brazil

^[3] Univ Sao Paulo, Inst Biociencias, Dept Botan, Rua Matao 277, BR-05508900 Sao Paulo - Brazil

^[4] Univ Estadual Campinas, UNICAMP, Inst Biol, Dept Biol Anim, CP 6109, BR-13083970 Campinas, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Biotropica; v. 49, n. 6, p. 832-837, NOV 2017.
• Citações Web of Science: 1

Resumo

According to apparent competition theory, the co-occurrence of two species that share the same predators appears to affect each other's population growth and abundance. However, due to habitat loss and over-hunting, top predators are being made rare worldwide. Considering that apparent competitors share similar resources, we would expect the absence of top predators to reflect in changes on prey realized trophic niches. To test our hypothesis, we developed a model to predict the abundance ratio of apparent competitor species based on changes in their realized trophic niches. We tested our model against field data on the Neotropical marsupials Didelphis aurita and Metachirus nudicaudatus. Our results revealed that D. aurita and M. nudicaudatus are two species under apparent competition and their realized trophic niche and diet overlap change according to the presence of top predators. The model was able to predict the actual relative abundances of D. aurita and M. nudicaudatus in the three empirical studies analyzed. Our study presents quantitative support to the apparent competition theory; however, the model's applications to other groups still need to be verified. Additionally, our study shows that the lack of top predators has consequences on the realized trophic niche of their prey, and therefore, we reinforce that conservation plans need to focus on the effects of top predator loss on ecosystems. Abstract in Portuguese is available with online material. (AU)

• Processo FAPESP: 11/10137-8 - Formigas em bromélias: efeitos em cascata sobre diversidade de artrópodes, ciclagem de nutrientes e ecofisiologia das plantas hospedeiras
• Beneficiário: Ana Zangirólame Gonçalves
• Modalidade de apoio: Bolsas no Brasil - Doutorado