Diversity and distribution patterns of Pronophilina butterflies (Lepidoptera: Nymphalidae: Satyrinae) along an altitudinal transect in north-western Ecuador

Abstract

Diversidad y Patrones de Distribución de Mariposas de la Subtribu Pronophilina (Lepidoptera: Nymphalidae: Satyrinae) en un Transecto Altitudinal en el Nor-Oeste de Ecuador RESUMEN -Se realizó en Ecuador un muestreo de mariposas de la subtribu Pronophilina con el fi n de evaluar los efectos de altitud sobre los patrones de distribución, diversidad y estructura de la comunidad en un transecto altitudinal. Se demostró una correlación signifi cativa de todos los índices de diversidad y altitud. El máximo de diversidad expresado por la riqueza de especies, fue reportado a 2600 m. Se identifi caron dos grupos de especies en la parte inferior y superior del transecto. La comparación de los coefi cientes de similitud indicó valores menores en la franja de altitud intermedia. Se demostró que varios pares de especies relacionadas morfo y ecológicamente tienen distribuciones altitudinales mutuamente exclusivas. La comparación con estudios semejantes revelaron una congruencia muy notable en cuanto a los patrones de diversidad altitudinal de los Pronophilina en varias áreas de la cordillera Andina. En particular, el índice de Shannon llega a valores máximos entre 2600 m y 2850 m, aproximadamente 400 -500 por debajo del limite superior del bosque nublado. El aumento de la diversidad de los Pronophilina con la altitud puede ser relacionado tan solo de manera marginal con la mayor disponibilidad de los recursos limitados. La menor presión por parte de los depredadores, parasitoides y ectoparásitos en mayores altitudes puede contribuir a la mayor abundancia pero no directamente a la diversidad. Esta última, está relacionada con las características intrínsicas del grupo, tales como el solapamiento de grupos faunísticos elevacionales y la tasa de especiación más rápida en el límite superior del bosque.PALABRAS CLAVES: Distribución altitudinal, bambú Chusquea, especie parapátrida, especiación, riqueza de especies ABSTRACT -Samplings of Pronophilina, a species-rich group of neotropical montane butterfl ies, were carried out along an elevational transect in Ecuador to assess the effect of altitude on their distribution patterns, diversity and community structure. All diversity indices were signifi cantly correlated with altitude. Maximum diversity expressed in species-richness, Shannon index and Fisher alpha was recorded at 2600 m. Two assemblages of species were identifi ed in the lower (below 2100 m) and upper (above 2300 m) sections of the transect by means of correspondence (CA) and cluster analysis. A comparison of Sørensen similarity coeffi cients showed lower values, thus higher turnover in the intermediate elevational band. Several closely related morphologically and ecologically species were found to have mutually exclusive altitudinal distribution patterns. A comparison with similar studies in Venezuela, Colombia and Peru revealed far reaching congruency of the patterns of altitudinal diversity of Pronophilina in distant areas of the Andes. In particular, the Shannon index reaches its maximum values at 2600-2850 m, which in...

Butterflies of the high-altitude Atacama Desert: habitat use and conservation

“…Butterflies are closely linked to plants, both as herbivores and pollinators, and previous work suggests that the altitudinal distribution of a butterfly might depend on that of its larval host plant (Brehm et al, 2003; Pyrcz et al, 2009) and hence that altitudinal patterns in butterfly diversity might match those of plants. The larval forms and host plants have been described for some of the species (Courtney and Shapiro, 1986b; Shapiro and Courtney, 1986; Benyamini, 1995; Beccaloni et al, 2008), and these fit with the observations recorded here.…”

Species Richness and Phenology of Butterflies Along an Altitude Gradient in the Desert of Northern Chile

“…Butterflies are closely linked to plants, and previous work suggests that the altitudinal distribution of a butterfly might depend on that of its larval host plant (Brehm et al, 2003;Hodkinson, 2005;Pyrcz et al, 2009). Altitudinal patterns in butterfly diversity are often similar to those of plants (Hawkins and Porter, 2003), and reflect both the organisms' environmental requirements and the trophic relationships between them.…”

“…However, empirical studies show that a variety of different patterns can exist: species richness sometimes increases and sometimes decreases with altitude, and the most common pattern involves a richness peak at mid-elevation (Grytnes and McCain, 2007). For instance, in the tropical Andes, the diversity of butterflies (Pyrcz et al, 2009) and of geometrid moths (Brehm et al, 2007) peaks at mid-elevation.…”

The Presence–Absence Situation and Its Impact on the Assemblage Structure and Interspecific Relations of Pronophilina Butterflies in the Venezuelan Andes (Lepidoptera: Nymphalidae)

“…The sample in Monte Zerpa is much more typical with no single species domination and five co-dominant species representing together over 60 % of all specimens (Pyrcz & Wojtusiak 1999, 2002, Pyrcz 2004, Pyrcz et al 2009b, Mahecha Jimenez et al 2011). The models of species abundance show best fit for broken stick model for Monte Zerpa, which agrees with the assumption that it describes the assemblages with no single species dominance and high evenness.…”

“…The distribution of Pronophilina species in well-defined elevational belts and the occurrence of pairs of related and/or similar species apparently replacing each other in altitude were first explored by Adams (1985) and more thoroughly investigated by Pyrcz et al (2009b). Adams was unable to propose an ecological mechanism responsible for maintaining altitudinal parapatric distributions.…”