Thread by @rafabppinheiro

1. In this thread I explain some discoveries of our study, leaded by @AlanFecchio and published in @molecology.
doi.org/10.1111/mec.15…. #avianmalaria @AvianMalaria

2. This study is a large collaboration, with 30 scientists from at least 20 different institutions in Brazil, Argentina and USA. This is awesome and I am very happy to be part of it.
Btw, I just defended my PhD in Ecology, in the Federal University of Minas Gerais, Brazil. 😉

3. The study crosses the borders of academic fields: ecology, evolutionary biology, parasitology, genetics, zoology … Here I focus on the ecological analysis and results. Other authors (@AlanFecchio) are more able to explain other aspects of the study.

4. We analyzed the occurrence of 520 genetic lineages of parasites that causes avian malaria, in 7534 blood samples from 806 bird species collected in 41 communities. It is a huge database, only made possible by collaborative science and by the tremendous efforts of @AlanFecchio.

5. 8 biomes, from Patagonia to Amazonia, and a latitudinal gradient of 4700 km. We studied the main factors that affects parasite distributions in South America.

6. We used Mantel Tests, to test the effects of distance, climate and host community composition on the assembly of parasites.

7. In simple questions: Communities that (1) are geographically close, (2) have similar climate, (3) presents similar bird assemblages) tend to have relatively similar parasite assemblages? Answers are yes, yes and yes. 👍👍👍

8. However, if two communities are geographically close, they likely also have similar climates and bird assemblages. 🧐
Thus, we used Partial Mantel Tests to control the factors’ effects on one another.

9. And then we found an interesting result: geographical distance and climate almost only affect parasite distributions indirectly, by affecting host distributions. Close and climatically similar communities share many parasite lineages because they share many bird species. ⭐️

10. The thickness of the arrows is proportional to the correlation coefficient. Grey arrow indicates nonsignificant correlations. Quadrant (a): Mantel tests. Quadrants (b),(c) and (d), partial Mantel tests.

11. Take home lesson 1: for #avianmalaria, parasite community assembly is mostly governed by host composition. Host composition, however, is affected by environmental conditions and geographical distance, creating an indirect correlation.

12. One of the main spatial patterns on the global biodiversity is the Latitudinal Diversity Gradient (LDG). In simple words, diversity increases from the poles towards the equator: more species, and more phylogenetical, morphological and functional diversities.

13. This pattern was observed in hundreds of studies, for different groups of species, as birds, threes and insects (doi.org/10.1086/381004). However, we don’t know if LDG stands also for parasites, and some authors suggested parasites are unlike to show such gradient.

14. Here, we show an evidence that corroborates the LDG for parasites that causes avian malaria. Parasite richness (number of lineages in each community) tends to decrease with increasing latitude.

15. But, as parasite distributions are highly affected by host distributions, LDG for parasites is probably mediated by the LDG for hosts. Communities with higher bird richness supports more avian malaria lineages. 🦅🦜🦆🐦

16. Take home lesson 2: #avianmalaria parasite in South America shows a Latitudinal Diversity Gradient, probably mirroring a similar pattern in the diversity of their host species.

@AlanFecchio @molecology @AvianMalaria @threadreaderapp unroll.