Comparison of exclusion between Nymphalidae species and season in a tropical dry forest of Morelos, México.

ATBC+OTS Joint 50th Anniversary Meeting-San José, Costa Rica June 23-27, 2013

Grégory Michaël Charre Marcela Osorio Beristain Luc Legal Néstor A. Mariano,Laboratorio de Ecología Animal, departamento de biología Universidad Autónoma Metropolitana poyotl@hotmail.fr, Departamento de Ecología

Centro de Investigación en Biodiversidad y Conservación, Univ. Aut. del Edo de Morelos mosorio@uaem.mx Université Paul Sabatier, Toulouse 3 luc.legal@univ-tlse3.fr Departamento de EcologíaCentro de Investigación en Biodiversidad y ConservaciónUniv. Aut. del Edo de Morelos nestor@uaem.mx

RESULTS

We encountered a total of 19 species (Table 1). Females excluded more than predicted in the dry season, the same was true for males in the rainy season (Fig.1. Females expelled more males according to the maximal temperatures (Fig.2), and less males with precipitations (Fig.3), according to the linear regressions results. More than 90 % of exclusion activity was represented by Myscelia cyananthe (Biblidinae) for both seasons. Crosstabulation analysis revealed that a dependency exists between species and sex, and at the same time between season and sex (Table 2).

Asterocampa idyja (Apaturinae) Hamadryas amphinome (Biblididae)

Smyrna blomfildia (Nymphalinae)

Stan

dard

ized

Resid

uals:

<-4

-4:-2

-2:0

0:2

2:4

>4

greg

lluv sec

mac

hem

Table 2. Standard residuals of cross tabulation analysis between butterfly sex and season.Pearson's Chi-squared test with Yates' continuity correction: X2= 38.3669, df = 1, p-value = 5.862e-10

INTRODUCTION

In Mexico, the tropical dry forest suffers from a strong food resources scarcity during the dry season (Mooney et al 1995). Within some families of Lepidoptera such as Nymphalidae, few species can survive to this season, using the decayed pulp fruits available as aliments (De Leon-Ibarra 2005). This plays an important role in their nutritional and matting ecology. That is why during mating season, i.e. the rainy season, sex ratio is in favour of males, close to 2:1, showing more exclusion behaviour for food and mate (Torres et al. 2008). However, little is know concerning lepidotperian sex ratio and behaviour during the dry season.

OBJECTIVE

We wanted to know if exclusion disparities for food exist between sexes of Nymphalidae species in two contrasting seasons of a deciduous tropical forest in Mexico.

HYPOTHESIS

We hypothesized that females will be more aggressive than males to defend aliment in the dry season, due to an absence of reproduction.

METHODS

We used fermented fruit baits (Hughes et al. 1998 modified) to compare the temporal abundance, sex ratio, and species exclusion frequency in Nymphalidae species during 12 months (oct 2007 to sep 2008), in the Sierra de Huautla, Estado de Morelos, México. We ran statistical analysis on log-transformed data using R statistical software ver. 2.8.0 (R Development Team 2008).

DISCUSSION

Our results highlighted that seasonality in dry/wet ecosystems dictates the variation in the abundance of Nymphalids as demonstrated Braby (1995).

Little is known about sex ratio changes between seasons (Torres et al. 2009), especially for female activity. Nevertheless, females expelled more in dry season maybe due to that fruits served as a great source of carbon for future egg production on fruit-feeding butterflies (Fisher et al. 2004, Molleman et al 2008).

On the contrary male behaviour is well-documented. In the rains, defend aliment, host plants, and available females requires more energy so that body weight predicts males territorial success (Peixoto & Benson 2008) and contest (Kemp 2000),

Climate plays a key-role in males as shown by Ide (2002): territorial behaviour is regulated directly by temperature and reproduction depends on precipitation for this family (Kemp 2001). This elucidated why males are so aggressive during the wet season.

These results suggest differential resource exploitation and exclusion behaviour for a dominant species of the deciduous tropical forest. Females of Myscelia cyananthe showed more aggressive patterns than other species or males.

Molleman F., Ding J., Wang J. L., Brakefi eld P. M., Carey J. R., Zwaan B. J. 2008. Adult diet affects life span and reproduction of the fruit-feeding butterfl y Charaxes fulvescens. Entomologia Experimentalis et applicata 129: 54-65.

Species OCT NOV DIC ENE FEB MAR ABR MAY JUN JUL AGO SEPTSiproeta steneles 0.25 0.86 1.14Smyrna blomfildia 3.75 0.33 1.00 1.33 3.00 1.00 0.86 0.57 0.86 1.14Myscelia cyananthe 1.25 1.67 11.50 8.33 7.67 7.00 6.57 6.00 4.57 3.71 2.86Hamadryas glauconome 0.25 0.33Hamadryas guatamalena 1.00 0.33 2.33 0.29 0.86 0.57 0.29Doxocopa laure 0.25 0.29 0.86 0.29Bolboneura sylphis 0.75 0.33 0.50 0.57 0.57 0.29 0.29 0.29Asterocampa idyja 0.25 0.86 2.00 1.71Anaea aidea 3.25 0.33 2.67 1.50 1.33 2.86 0.29 1.43 0.86 0.86Cissia similis 6.33 2.33 19.00 4.00 6.33 4.33 0.86 0.86 0.29 0.57Hermeuptychia hermes 0.33 0.67 8.50 1.67 2.00 1.00 0.29 0.57 0.57 0.29 0.29Pindis squamistriga 0.33Cissia themis 0.67 0.50 0.33 1.00 1.14 2.29 2.00 0.86 2.00Cyllopsis nayarit 1.00Euptychia fetna 1.00 0.33 0.33 0.29 0.29 0.29Cyllopsis perplexa 0.33Hamadryas februa 0.33 0.67 0.29 0.29 0.29Hamadryas amphinome 1.00 1.00 0.33 0.29 0.29Cissia cleophes 0.33

REFERENCES

De Leon-Ibarra M. A. 2005. Fenología de especies de plantas con frutos carnosos y disponibilidad espacial y temporal de este recurso en la reserva de la biosfera Sierra de Huautla: Implicaciones para los vertebrados. Undergraduate thesis, Universidad Autónoma del Estado de Morelos, Cuernavaca, 74 p. Hughes, J. B., Daily, G. C., & Ehrlich, P. R. 1998. Use of fruit bait traps for monitoring of butterflies (Lepidoptera: Nymphalidae). Revista de biología tropical, 46(3), 697-704.Mooney H. A., Bullock S. H., Medina E. 1995. Introduction, p. 1-8 in: Bullock S. H., Mooney H. A, Medina, E. (Eds.). Seasonally Dry Tropical Forest, Cambridge University Press, Cambridge. R development core team. 2008. R: a language and environment for statistical computing. R foundation for statistical computing. www.R- project.org.Torres, C., Osorio-Beristain, M., Mariano, N. A., & Legal, L. 2009. Sex-dependent seasonal feeding activity variations among two species of Nymphalidae (Lepidoptera) in the Mexican tropical dry forest. In Annales de la Societe Entomologique de France (Vol. 45, No. 3, p. 265).

Table 1. A. Mean precipitations and temperatures in “El Limón” B. Butterflies occurrence and relative abundance in “El Limón”. All data range from Oct 2007 to Nov 2008.

A

B

mm ºC

Prec

ipita

tion

Temperature

Fem

ale

Dry SeasonRainy season

Mal

e

Figure 3. Females excluding males from puddling baits according to precipitations. R2=0.3508, F=5.40, p=0.042.

Figure 1. males excluding females from puddling baits according to precipitations. R2=0.3853, F=6.27, p=0.031.

Figure 2. Females excluding males from puddling baits according to maximum temperatures. R2=0.3289F=4.90, p=0.05.