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Abstract
Two species of columnar cacti, Subpilocereus repandus and Stenocereus griseus, are pollinated on Curacao by two species of glossophagine bats, Leptonycteris curasoae and Glossophaga longirostris (Phyllostomidae). The pollination effectiveness of the two bat species can influence the evolution of this mutualism as well as the immediate availability of resources to frugivores and omnivores. I examined the effectiveness of single-visits by L, curasoae and G. longirostris on fruit-set, seed number, and fruit size for each cactus species. Single visits of L. curasoae produced higher fruit-set and seed number in Subpilocereus repandus than did single visits of G, longirostris, but the differences were not statistically significant, possibly as a result of the small size of the L, curasoae sample. The reverse trends were observed for Stenocereus griseus, Pollination of Subpilocereus repandus by L, curasoae resulted in significantly longer fruits than did pollination by G. longirostris, During the peak of the flowering season, flowers received many visits per night. Fruit size (length, width, total mass, pulp mass) was positively correlated with the number of seeds per fruit. These results indicate that the species of bats visiting cactus flowers, as well as the number of visits to flowers, may affect pollination success, and consequently may affect the carrying capacity of the environment in terms of fruit resources for animals that feed on cactus fruits.
... Las especies insectívoras son, según nuestros datos, importantes controladores de insectos dañinos. Las especies primariamente nectarívoras (también consumen polen, fruta, e insectos presentes en las flores y en la fruta) son importantes polinizadores y dispersores de semillas de plantas de ambientes áridos o semi-áridos como los que predominan en la península (Sosa & Soriano 1993;Petit 1995Petit , 1997Nassar et al. 1997Nassar et al. , 2003Ruiz et al. 1997). ...
... Clasificada como especie "Vulnerable" por aplicación del criterio A2c de la Unión Internacional para la Conservación de la Naturaleza (UICN 2001;Nassar 2008). Es indispensable para la polinización de cactos columnares, agaves y otras plantas en las zonas áridas de Venezuela y Curaçao (Petit 1995(Petit , 1997Nassar et al. 1997Nassar et al. , 2003. También actúa como agente dispersor de semillas de cactos (Sosa & Soriano 1993). ...
... El deterioro de su población en Paraguaná no pondría a la especie en peligro debido su estatus de especie común, y a que tiene una amplia distribución fuera de la península. Sin embargo, debe ser protegida debido a los servicios ecosistémicos que presta polinizando flores y dispersando semillas de plantas, especialmente cactos columnares y agaves, en zonas áridas (Sosa & Soriano 1993;Petit 1995Petit , 1997Nassar et al. 1997Nassar et al. , 2003Ruiz et al. 1997). ...
We synthesize the biological information available on the six species of cave-dwelling bats of Paraguaná Peninsula, adding new data on morphological differentiation, feeding habits, socio-economic importance, conservation, and on the characteristics of the caves in which they roost. Of these species, four are important insect pest controllers, and two are important pollen and seed vectors of native plants. Five species are strictly cavernicolous, for which reason they share two natural risk factors. First, because they roost in only three caves, their populations are extremely vulnerable to a catastrophic event in any of them. Second, because their females produce a single pup per year, their populations have a low capacity to recover, and a high probability of extinction, in the event of a major loss. The most direct threat to these bats is vandalism in caves, remediable through:1) legislation, such as the recent decree creating the “Santuario de Fauna Silvestre Cuevas de Paraguaná”; 2) gating to restrict access to the caves, a measure with numerous contraindications; 3) official wardens, so far non-existent; 4) environmental education, so far insufficient. Deforestation and indiscriminate use of pesticides are growing threats, remediable through: 5) expansion of protected areas, at present covering only 1.4% of the peninsula; 6) biological pest control; 7) crops that do not require pesticides. Wind turbines and natural collapse of caves are potential threats, remediable through: 8) mitigation of the effects of already installed wind turbines, and careful selection of sites for new ones; 9) reinforcement and repair of natural caves; 10) construction of artificial caves. For the latter initiative, we propose a design that we define as semi-spheroid with compartments. Artificial caves would accomplish five functions. First, reduce the extinction risk of bats by distributing their populations in a larger number of roosts. Second, increase the populations of insectivorous bats to boost their effect as natural pest controllers. Third, use these caves for the production of easily harvested guano to be used as a fertilizer. Fourth, serve as a tool for the biological study of cavernicolous bats and of the ecosystem services provided by them. Fifth, utilize these caves for ecotourism in benefit of local communities.
... The highest levels of bat specialization among cacti have been observed in species restricted to Neotropical regions, including Mexico (Valiente-Banuet et al., 1996, 1997a, Central America (Tschapka et al., 1999), the Caribbean (Petit, 1995), and Venezuela (Nassar et al., 1997). In Venezuela, strict bat pollination has been identified in at least five cactus species with similar reproductive characteristics and genetic self-incompatibility. ...
... M. Nassar, unpublished data). The three species are self-incompatible based on hand-pollination experiments and nectar-feeding bats are nearly the only effective pollinators of these cacti (Petit, 1995;Nassar et al., 1997). Fruits are multi-seeded (Ͼ1000) berries, and dispersal is mainly performed by bats and also several birds (Bosque, 1984;Sosa and Soriano, 1993;Soriano et al., 1999). ...
... Low population structure in bat cacti is consistent with the flight capabilities of bats in general and the southern long-nosed bat, Leptonycteris curasoae, in particular. This nectar-feeding bat pollinates and disperses columnar cacti in North America (Fleming et al., 1996), the Netherlands Antilles (Petit, 1995), and northern South America (Nassar et al., 1997) and can forage among locations separated by up to 14 km and fly as much as 100 km in a single night (Horner et al., 1998). Compared to bats, birds that disperse cactus seeds in Venezuela seem to have a relatively restricted radius of activity based on their reported home ranges (Ͻ12 ha) and their resident status (Bosque, 1984). ...
We conducted allozyme surveys of three Venezuelan self-incompatible chiropterophilous columnar cacti: two diploid species, Stenocereus griseus and Cereus repandus, and one tetraploid, Pilosocereus lanuginosus. The three cacti are pollinated by bats, and both bats and birds disperse seeds. Population sampling comprised two spatial scales: all Venezuelan arid zones (macrogeographic) and two arid regions in northwestern Venezuela (regional). Ten to 15 populations and 17-23 loci were analyzed per species. Estimates of genetic diversity were compared with those of other allozyme surveys in the Cactaceae to examine how bat-mediated gene dispersal affects the population genetic attributes of the three cacti. Genetic diversity was high for both diploid (P(s) = 94.1-100, P(p) = 56.7-72.3, H(s) = 0.182-0.242, H(p) = 0.161-0.205) and tetraploid (P(s) = 93.1, P(p) = 76.1, H(s) = 0.274, H(p) = 0.253) species. Within-population heterozygote deficit was detected in the three cacti at macrogeographic (F(IS) = 0.145-0.182) and regional (F(IS) = 0.057-0.174) levels. Low genetic differentiation was detected at both macrogeographic (G(ST) = 0.043-0.126) and regional (G(ST) = 0.009-0.061) levels for the three species, suggesting substantial gene flow among populations. Gene exchange among populations seems to be regulated by distance among populations. Our results support the hypothesis that bat-mediated gene dispersal confers high levels of genetic exchange among populations of the three columnar cacti, a process that enhances levels of genetic diversity within their populations.
... La polinización, junto con la dispersión de semillas y el establecimiento de plántulas son procesos clave que determinan el éxito reproductivo de gran parte de las angiospermas (Herrera y Pellmyr 2002, Schupp 1995. Un gran número de especies en el Neotrópico son polinizadas efectivamente por murciélagos, entre las que se encuentran especies de familias de plantas suculentas como Cactaceae y Agavaceae (Alcorn 1961, Arizaga et al. 2000, Casas et al. 1999, Fleming et al. 1996, Ibarra-Cerdeña et al. 2005, Méndez et al. 2005, Molina-Freaner et al. 2004, Muchhala 2003, Nassar et al. 1997, Petit 1995, Ruiz et al.1997, Sahley 1996, Sazima y Sazima 1978, Sazima et al. 2003, Tschapka y von Helversen 1999, Tschapka 2003y Valiente-Banuet et al. 1996, 1997a1997b. ...
... La biología floral, junto con las relaciones ecológicas y el sistema reproductivo que presentan estas flores, ha demostrado la estrecha asociación entre murciélagos (principalmente glosofaginos) y cactus columnares. Esta relación mutualista ha sido documentada para zonas áridas del Caribe, Norte y Suramérica, comprendidas entre el sureste de Estados Unidos, Norte y centro de México, Curazao, Colombia y Venezuela (Nassar et al. 1997, Petit 1995, Ruiz et al. 1997, Soriano y Ruiz 2002, Sosa 1991, Valiente-Banuet et al.19961997a1997b. ...
... En estas especies Nassar et al. (1997) demostraron la estrecha relación de las flores y sus polinizadores, dado que en ausencia de los murciélagos no hay producción de frutos. En Curazao, son murciélagos glosofaginos los principales visitantes de C. repandus y S. griseus (Petit 1995). Otros estudios con cactáceas de la tribu Pachycereeae en el Sureste de los Estados Unidos, han evidenciado la presencia de diversos visitantes nocturnos (murciélagos y lepidópteros nocturnos) y diurnos (aves e insectos) que contribuyen en la polinización (Alcorn 1961, Fleming et al. 1996, Molina-Freaner et -6 -al. ...
Mecanografiado Tesis (Lic. en Biología)-- Universidad de Los Andes, Facultad de Ciencias, Departamento de Biología, Mérida, 2007 Incluye bibliografía
Estudios de biología reproductiva de cuatro especies de cactáceas columnares en la región Norte costera venezolana, han evidenciado la estrecha relación que se ha establecido entre cactus y murciélagos en estos ecosistemas. Las cactáceas columnares de bolsones áridos de los Andes venezolanos han recibido poca atención en cuanto a la biología reproductiva, por lo que en este trabajo evaluamos la biología de la polinización de Pilosocerus tillianus Gruber & Schatzl, un cactus columnar endémico del enclave de Lagunillas, en los Andes de Venezuela. Los trabajos sobre dieta de los glosofaginos G. longirostris y L. curasoae en los enclaves semiáridos de Venezuela y Colombia, han puesto en evidencia el consumo de frutos y, posiblemente, polen de Pilosocereus spp. Existe un conjunto de hechos que nos induce a cuestionar la efectividad de la reproducción sexual en esta especie, los cuales son: a) una baja producción de flores de P. tillianus con respecto a las otras dos especies de cactus columnares
del enclave de Lagunillas, b) se ha observado gran cantidad de individuos de P. tillianus derivados por reproducción vegetativa c) por otro lado, P. moritzianus ha sido referida como parcialmente auto-compatible. Por lo tanto, en el desarrollo de este trabajo quisimos dar respuesta a las
- 2 -
Mediante observaciones directas y ensayos de campo evaluamos la morfología floral de P. tillianus y verificamos su concordancia con el síndrome de quiropterofilia, además, determinamos el patrón de producción de néctar y la concentración de azúcares en sus flores. Empleando una cámara de visión nocturna determinamos los visitantes de flores en antesis y sus tasas de visita, para luego estudiar la asociación entre la producción y concentración de néctar
con las visitas de las especies más importantes. Verificamos el grado de autocompatibilidad de la especie mediante ensayos de reproducción y la efectividad de los murciélagos en la polinización por exclusión de visitas. Las flores son hermafroditas, exhibieron una marcada antesis nocturna, su longitud promedio fue de 53,37 ± 0,95 mm y su diámetro promedio fue de 38,18 ± 1,16 mm. La producción y concentración de néctar mostró un patrón unimodal a lo largo
de la noche, su volumen total promedió 946,42 ± 106,04 µl y su máximo de concentración de azúcares fue de 19,16 ± 0,45 %. Las flores fueron visitadas principalmente por el murciélago Glossophaga longirostris (92,1 % de visitas) lo que sugiere que su polinización depende de estos animales (síndrome quiropterofílico), otros animales como; lepidópteros nocturnos, ortópteros y dictiópteros también visitaron sus flores en menor proporción (7,9 % de visitas).
Nuestros resultados sugieren una asociación positiva entre el ritmo de producción de néctar y la tasa de visitas de los murciélagos. No hubo formación de frutos en ausencia de los murciélagos. Sin embargo, los ensayos de sistemas de reproducción revelaron que las flores son autocompatibles no autogamas. Discutimos la importancia de los murciélagos glosofaginos para el mantenimiento
de la variabilidad genética y la conservación de P. tillianus.
... Bibliografía. de Buisonjé (1974), Petit (1995), Debrot (1997), Freitas et al. (2005), Nassar (2008 ...
... Bibliografía. Fleming y Nassar (2002), Petit (1995), Petit et al. (2006), Nassar (2008), . ...
El área contiene una muestra representativa de la comunidad de murciélagos del suroeste de Perú y norte de Chile. Incluye 18 de las 20 especies registradas para esta región. IUCN: En Peligro (Tomopeas ravus y Myotis atacamensis), Vulnerable (Amorphochilus schnablii), Casi Amenazada (Platalina genovensium) y Datos Deficientes (Promops davisoni), las cuatro primeras Amenazadas o Casi Amenazadas en Perú. Asimismo, Eumops chiribaya y Lasiurus arequipae cumplirían con IUCN para ser consideradas como amenazadas. Tres de las especies reportadas son endémicas de Perú (T. ravus, E. chiribaya y L. arequipae) y ocho son endémicas del Desierto Pacífico de Perú y norte Chile (las enlistadas anteriormente y Mormopterus kalinowskii). Existen colonias reproductivas de especies amenazadas, refugios permanentes. El área sufre de vandalismo y disminución de la calidad del hábitat.
... Bibliografía. de Buisonjé (1974), Petit (1995), Debrot (1997), Freitas et al. (2005), Nassar (2008 ...
... Bibliografía. Fleming y Nassar (2002), Petit (1995), Petit et al. (2006), Nassar (2008), . ...
El área posee una alta diversidad de murciélagos (cinco especies) en relación a la riqueza de la provincia de San Juan, donde solo se registraron seis especies. Se reportan dos especies migratorias: Tadarida brasiliensis (Molossidae), Lasiurus blossevillii
(Vespertilionidae), además de colonias maternales de Myotis dinellii y Tadarida brasiliensis. En el interior del área existen comunidades humanas con intensas actividades productivas como la ganadería, agricultura y turismo.
Los murciélagos registrados en el área son insectívoros por lo que ejercen una importante actividad reguladora de las poblaciones de insectos perjudiciales para los bosques nativos, la agricultura y vectores de enfermedades.
... Bibliografía. de Buisonjé (1974), Petit (1995), Debrot (1997), Freitas et al. (2005), Nassar (2008 ...
... Bibliografía. Fleming y Nassar (2002), Petit (1995), Petit et al. (2006), Nassar (2008), . ...
... Bibliografía. de Buisonjé (1974), Petit (1995), Debrot (1997), Freitas et al. (2005), Nassar (2008 ...
... Bibliografía. Fleming y Nassar (2002), Petit (1995), Petit et al. (2006), Nassar (2008), . ...
Este libro es el corolario de muchos años de trabajo y dedicación de los miembros de la RELCOM (Red Latinoamericana y del Caribe para la Conservación de los Murciélagos), cuyo objetivo es poner a disposición de la comunidad los resultados de una actividad de carácter regional, que se viene realizando de manera ininterrumpida desde 2011, cuando el primer AICOM fue reconocido. En 2009, la RELCOM elaboró una “Estrategia para la conservación de los murciélagos en Latinoamérica y el Caribe”, donde se identificaron las amenazas que sufren los murciélagos de la región. Esto despertó la necesidad de crear
una figura como grupo para proteger a los murciélagos a través de una propuesta regional. Y es así que surgen las Áreas y Sitios de Importancia para la Conservación de los Murciélagos (AICOMs-SICOMs), inspiradas en las AICAs (Áreas de Importancia para la Conservación de las Aves). El reconocimiento de AICOMs y SICOMs surge como una herramienta para que, de algún modo, pueda ser utilizada por los diferentes países que conforman la red, para orientar los planes de conservación en localidades donde especies y poblaciones de murciélagos se encuentren amenazadas. Si bien no es un instrumento legal, sienta bases para el desarrollo de políticas nacionales y regionales que avancen en ese sentido.
... Además de otros vertebrados e.g., quirópteros (Soriano et al. 1991, Petit 1995, 2011, Valiente-Banuet et al. 1995, Nassar et al. 1997, Nassar et al. 2003, Naranjo et al. 2003, Ibarra-Cerdeña 2005, Rengifo et al. 2007), varias especies de aves son consumidoras habituales de néctar y frutos de cactáceas (Grant & Grant, 1981, Bosque 1984, Silva 1988, Wendelken & Martin 1988, Martínez del Río et al. 1992, Silvius 1995, Sosa & Soriano 1996, (Sosa & Soriano 1996, Soriano et al. 1999, Rengifo et al. 2007, Petit 1995, 2011. Por ejemplo, los frutos de Stenocereus griseus (Haw.) ...
... Además de otros vertebrados e.g., quirópteros (Soriano et al. 1991, Petit 1995, 2011, Valiente-Banuet et al. 1995, Nassar et al. 1997, Nassar et al. 2003, Naranjo et al. 2003, Ibarra-Cerdeña 2005, Rengifo et al. 2007), varias especies de aves son consumidoras habituales de néctar y frutos de cactáceas (Grant & Grant, 1981, Bosque 1984, Silva 1988, Wendelken & Martin 1988, Martínez del Río et al. 1992, Silvius 1995, Sosa & Soriano 1996, (Sosa & Soriano 1996, Soriano et al. 1999, Rengifo et al. 2007, Petit 1995, 2011. Por ejemplo, los frutos de Stenocereus griseus (Haw.) ...
Las plantas cactáceas están naturalmente circunscritas al continente americano, y el consumo de sus frutos por las aves ha sido puntualmente estudiado en algunas áreas semiáridas caribeñas.Este estudio cuantifica aspectos ecológicos de la ornitofrugivoría en dos cactáceas columnares: Stenocereus griseus (Sg) y Cereus repandus (Cr), en el nororiente de Venezuela. Se recolectaron frutos maduros para la medición de contenido de semillas y algunos parámetros morfométricos. Durante la maduración de los frutos se practicaron cuatro sesiones de observación, en junio (n=3) y septiembre (n=1), para Sg, y en julio (n=4), para Cr, divididas en cuatro lapsos: 07.00-09.00 am, 09.00-11.00 am, 11.00 am-01.00 pm y 1.00 -03.00 pm, promediándose la temperatura ambiental para cada lapso. Se determinaron número de individuos y especies de aves consumidoras por lapso, frecuencia y duración de las visitas y pugnacidad intra e interespecífica. En promedio, los frutos de Sg fueron ligeramente más grandes que los de Cr, pero con una cantidad similar de semillas, aunque Cr casi duplicó a Sg en el número de semillas estériles. Trece especies consumieron frutos de las dos especies de cactáceas, pero Leucippus fallax sólo consumió frutos de Sg, mientras Saltator coerulescens, Mimus gilvus y Campylorhrynchus griseus sólo de Cr. Coereba flaveola acaparó el mayor porcentaje de visitas en ambas cactáceas. En Sg, la frecuencia de las visitas fue significativamente mayor durante el primer lapso matutino (7-9 am) que en el resto; sin embargo, ésta fue similar para todos los lapsos en Cr. Competitivamente, Melanerpes rubricapillus fue la especie más dominante, mientras C. flaveola tuvo la mayor pugnacidad, intra e interespecífica.
... Además de otros vertebrados e.g., quirópteros (Soriano et al. 1991, Petit 1995, 2011, Valiente-Banuet et al. 1995, Nassar et al. 1997, Nassar et al. 2003, Naranjo et al. 2003, Ibarra-Cerdeña 2005, Rengifo et al. 2007), varias especies de aves son consumidoras habituales de néctar y frutos de cactáceas (Grant & Grant, 1981, Bosque 1984, Silva 1988, Wendelken & Martin 1988, Martínez del Río et al. 1992, Silvius 1995, Sosa & Soriano 1996, (Sosa & Soriano 1996, Soriano et al. 1999, Rengifo et al. 2007, Petit 1995, 2011. Por ejemplo, los frutos de Stenocereus griseus (Haw.) ...
... Además de otros vertebrados e.g., quirópteros (Soriano et al. 1991, Petit 1995, 2011, Valiente-Banuet et al. 1995, Nassar et al. 1997, Nassar et al. 2003, Naranjo et al. 2003, Ibarra-Cerdeña 2005, Rengifo et al. 2007), varias especies de aves son consumidoras habituales de néctar y frutos de cactáceas (Grant & Grant, 1981, Bosque 1984, Silva 1988, Wendelken & Martin 1988, Martínez del Río et al. 1992, Silvius 1995, Sosa & Soriano 1996, (Sosa & Soriano 1996, Soriano et al. 1999, Rengifo et al. 2007, Petit 1995, 2011. Por ejemplo, los frutos de Stenocereus griseus (Haw.) ...
Keywords: Cactaceae – ornithofrugivory – Venezuela Cacti are naturally circumscribed to the American continent but the fruit consumption for birds has received little attention in Caribbean semiarid lands. In this paper we quantify the consumption of fruit of columnar cacti Stenocereus griseus (Sg) and Cereus repandus (Cr) by birds in northeastern Venezuela. During the fruit season, we collected ripe fruits and analyzed seed amount and some morphometric parameters. We practice four observation sessions in both cacti, on June (n=3) and September (n=1) for Sg and July (n=4) for Cr. pm, and the average temperature for each period was calculated. We determined visit number and duration, individuals and species consumers for each period, and intra and interspecific pugnacity. Sg fruits were slightly bigger than Cr fruits but both cacti had a similar amount of seeds; nevertheless, the amount of sterile seeds in Sr doubled that of Sg. Thirteen species consumed both cacti fruits, but Leucippus fallax only consumed Sg fruits, while Saltator coerulescens, Mimus gilvus and Campylorhrynchus griseus only consumed Cr fruits. Coereba flaveola accounts for the highest percentage of visits in both cactus species. In Sg visit numbers were markedly higher in the first morning period (7-9 am); nevertheless it was similar in all periods for Cr. Competitively, Melanerpes rubricapillus was the most dominant species, while C. flaveola showed the greatest intraspecific and interspecífic pugnacity.
... M. Moré referring to Diaz 2001. In contrast, the flowers of C. repandus are visited by several species of bats (Lemke 1985, as C. atroviridis;Nassar & al. 1997, Petit 1995and Petit 2011. Petit (1995) also recorded a single visit of an unidentified sphingid for C. repandus. ...
... In contrast, the flowers of C. repandus are visited by several species of bats (Lemke 1985, as C. atroviridis;Nassar & al. 1997, Petit 1995and Petit 2011. Petit (1995) also recorded a single visit of an unidentified sphingid for C. repandus. ...
Observations of plant-pollinator interactions are an important component of the study of the overall ecological setting of a plant species. Here, we report two species of sphingids as pollinators of Cereus aethiops, a wide-spread shrubby columnar cactus species from the Argentinian Monte vegetation. Cereus aethiops is remarkable for its desiccation tolerance during the dry winter season and rapid rehydration after the first rainfall during the summer season. Rehydration starts within 24 hours after the start of the first significant rain, and is complete within 7 to 10 days. Flower bud initiation is triggered by the first rainfall event, and the time from the first rain to the start of the flowering season shows little year-to-year variation. The flowers conform to the sphingophilous pollination syndrome, and the expected sphingid pollinators could be confirmed by direct observation. Diurnal plant-insect interactions in C. aethiops are insignificant and most likely do not contribute significantly to reproductive output.
... Amongst the cacti occurring in the Cadeia do Espinhaço (Minas Gerais, Brazil), Zappi (1989) suggested that species of Uebelmannia, Hatiora and Opuntia might be pollinated by bees, while species of Cereus, Discocactus and Arthrocereus might be pollinated by hawkmoths, Pilosocereus and Cipocereus are probably pollinated by bats, while Melocactus and Arrojadoa might be pollinated by hummingbirds, based on their fl oral morphology. Several studies of columnar cacti pollinated by bats have been published (McGregor et al. 1962;Fleming et al. 1994;Petit 1995;Valiente-Banuet et al. 1996;Rocha et al. 2007), and it is possible that this pollination syndrome will prove to be frequent, if not the most common one, within tribes Pachycereeae and Cereeae. Recent studies have increased the list of bat-pollinated cacti in the Neotropics, such as Pachycereus pringlei (Fleming et al. 1994), Neobuxbaumia mezcalaensis, Neobuxbaumia macrocephala (Valiente-Banuet et al. 1997), Stenocereus griseus, Pilosocereus moritzianus, Pilosocereus lanuginosus, Cereus [Subpilocereus] horrispinus (Nassar et al. 1997), Pilosocereus catingicola (Locatelli et al. 1997), and Pilosocereus tuberculatus (Rocha et al. 2007). ...
... Time elapsed between anthesis and fruit ripening is relatively short, as seen in other species of columnar cacti (Pimienta- Barrios & del Castillo 2002). Fertilized fl owers of C. lanifl orus develop into ripe fruits within 40 to 50 days, and similar results were seen in Pilosocereus lanuginosus, Stenocereus griseus and Cereus [Subpilocereus] repandus (Petit 1995 (Nassar et al. 1997) and is smaller than for Stenocereus griseus (76%) (Nassar et al. 1997). Th us, this species seems to have a normal rate of fruiting effi ciency, although about 89% of the control cross-pollinated of its fl owers produced fruits, which indicates the occurrence of pollen limitation. ...
Cipocereus laniflorus N.P. Taylor & Zappi is an endemic species from the Serra do Caraça, State of Minas Gerais, Brazil. In order to propose conservation strategies for this species, its reproductive strategies were investigated, including reproductive phenology, floral biology, floral visitors and breeding system. The flowering and fruiting period extends from May to October. Few flowers per plant open each night, producing up to 0.4 ml nectar, but 30% of them are nectarless. Probably pollen is also offered as a resource. Fruiting efficiency of C. laniflorus (47%) is close to that found in other Cactaceae species. Pollen of this species was detected in Anoura geoffroy, Soricina glossophaga and Pygoderma bilabiatum bats. Amongst the characteristics related to bat-pollination syndrome found in C. laniflorus, the cream-white colouring of the internal part of the flower, the numerous stamens and the nocturnal anthesis of short duration can be highlighted. Flowers of C. laniflorus are also visited by Nitidulidae beetles, Trigona fulviventris bees and hummingbirds, however bats are the main pollinators of this species. Finally, as a self-sterile species, C. laniflorus needs a pollinator and is more susceptible to the risk of extinction if local disturbances affect its pollination system.
... Atraen a los polinizadores por su olor y producen como recompensa por los servicios de polinización grandes cantidades de polen y néctar principalmente en el crepúsculo y la noche (Faegri & van der Pijl 1971 columnares existentes en México, muestran este síndrome de polinización (Valiente-Banuet et al. 1996). Las flores de los géneros Carnegiea, Pachycereus, Pilosocereus, Stenocereus y Subpilocereus poseen rasgos morfológicos y funcionales asociados claramente a la polinización por murciélagos, siendo éstos sus principales polinizadores (Petit 1995;Fleming et al. 1996;Valiente-Banuet et al. 1996;Nassar et al. 1997). Existen, sin embargo, desviaciones locales, ya que se ha reportado que en Norteamérica las flores de algunas cactáceas columnares como Carnegiea gigantea y Stenocereus thurberi (Foto 6) también atraen abejas, mariposas nocturnas, colibríes y otras aves (Fleming et al. 1996(Fleming et al. , 2001Fleming 2002). ...
... Se ha sugerido que como consecuencia de un sistema reproductivo xenógamo se pueden modificar los patrones fenológicos de floración en condiciones de competencia por polinizadores con otras especies (Fleming et al. 1996). Las especies autoincompatibles incluyen a Carnegiea gigantea, Pachycereus schottii, Pachycereus pecten-aboriginum, Stenocereus gummosus y S. thurberi en el suroeste de Estados Unidos y noroeste de México (Foto 12, 13 y 14) (Fleming et al. 1996(Fleming et al. , 2001Holland & Fleming 1998;Molina-Freaner et al. 2004), Neobuxbaumia mezcalaensis, N. macrocephala, N. tetetzo (Foto 15), Pachycereus weberi (Foto 16), Pilosocereus chrysacanthus, Stenocereus queretaroensis y S. stellatus en el centro y sur de México (Valiente-Banuet et al. 1996, 1997a, 1997bCasas et al. 1999b;Castillo Landero 2003) (Petit 1995;Sahley 1996;Nassar et al. 1997;Ruiz et al. 2000). De las especies que han sido estudiadas, únicamente en Pachycereus pringlei, Pilosocereus moritzianus, Polaskia chende, P. chichipe y Weberbauerocereus weberbauri se ha encontrado evidencia de autocompatibilidad (Fleming et al. 1994;Sahley 1996;Nassar et al. 1997;Cruz & Casas 2002;Otero-Arnaiz et al. 2003). ...
Resumen
Este trabajo es una revisión de la literatura publicada sobre la fenología y biología reproductiva de las cactáceas columnares. Primero, se presenta una introducción que incluye información sobre la distribución y características generales de las cactáceas columnares. Las características florales y su relación con los polinizadores, incluyendo los síndromes de polinización y los sistemas reproductivos, son tratadas posteriormente. La mayoría de las cactáceas columnares presentan flores hermafroditas; sin embargo, existen reportes de una especie trioica (Pachycereus pringlei) y otra androdioica (Neobuxbaumia mezcalaensis). El sistema reproductivo más común es el de xenogamia obligada (18 de 23 especies son incompatibles),
consecuentemente todas las especies estudiadas muestran gran dependencia de la actividad de los polinizadores, que incluyen murciélagos, aves, insectos y combinaciones de estos tres grupos. La fenología reproductiva parece responder, al menos en parte, a la ausencia de lluvias, fenómeno que está asociado a un proceso de floración generalmente unimodal. Sin embargo, existen reportes de especies que florecen en la época de lluvias y especies con patrones bimodales (Stenocereus griseus, S. queretaroensis) o multimodales (Pachycereus schottii, Cereus hexagonus). La fenología reproductiva de las especies silvestres, las especies
manejadas in situ y las cultivadas se incluye y se discute con respecto a la fenología y distribución de las especies. Finalmente, se hace una discusión sobre las perspectivas de investigación en cactáceas columnares.
Abstract
This article is a broad review of the available information on the phenology and reproductive biology of columnar cacti. A general introduction about the family Cactaceae is presented and emphasis is placed on the distribution and general features of columnar cacti. Some of the characteristics of their flowers and the relationship with pollinators (including pollination syndromes and reproductive systems) are treated later. All the species show a great dependence on pollinators (bats, birds and/or insects) for their reproductive success. Most of the species have hermaphroditic flowers; however, there is a trioecious species (Pachycereus pringlei)
and another that is androdioecious (Neobuxbaumia mezcalaensis). The most common reproductive system is obligate xenogamy (18 of 23 species studied are incompatible) or have mechanisms that promote cross pollination. The flowering peak usually occurs during the dry season. However, some species flower in the rainy season and other species show bimodal (Stenocereus griseus, S. queretaroensis) or multimodal flowering curves (Pachycereus schottii, Cereus hexagonus). The reproductive phenology of wild, managed in situ, and cultivated species is also included in this review. We conclude with a discussion on the perspectives of
further research in columnar cacti.
Key words: Columnar cacti, plant-animal interactions, pollination, reproductive phenology.
... In cacti, dependence on bat pollination increases latitudinally from the subtropics (Alcorn et al. * Correspondent: jnassar@oikos.ivic.ve 1959, 1962Fleming et al. 1996Fleming et al. , 2001Sahley 1996) to the tropics (Casas et al. 1999;Nassar 1991;Nassar et al. 1997;Petit 1995;Tschapka et al. 1999;Valiente-Banuet et al. 1996, 1997a, 1997bB. Rivera-Marchand, pers. ...
... This species is distributed in northern South America, including the Dutch Antilles, Trinidad, and nearby Caribbean islands (Webster and Handley 1986). The 2 species are the primary pollinators and seed dispersers of several columnar cacti in northern South America and the Lesser Antilles (Fleming and Nassar 2002;Nassar et al. 1997;Petit 1995;Soriano 1993, 1996). G. longirostris also disperses the seeds of plants in Moraceae and Elaeocarpaceae (Ruiz et al. 1997;Sosa and Soriano 1993). ...
We used stable carbon and nitrogen isotope analyses to test the hypothesis that nectar-feeding bats Leptonycteris curasoae and Glossophaga longirostris depend on cacti and agaves as food sources in Venezuelan arid zones and to compare their trophic positions. We measured the isotopic compositions of muscle tissue in the 2 species during 1 year at 3 arid locations. Overall carbon isotopic composition (∂13C) of L. curasoae (-11.76‰) and G. longirostris (-13.28‰) resembled values characteristic of columnar cacti and agaves (-12.47‰), which have in common the crassulacean acid metabolism (CAM) photosynthetic pathway. L. curasoae appears to be more dependent on cacti and agaves (98% CAM in the diet) than G. longirostris (85% CAM in the diet). CAM dependence, as we designate dependence on cacti and agaves, was evidenced across sites. Level of CAM dependence slightly varied over the year only in G. longirostris. We concluded that the 2 species of bats mainly rely on CAM plants in Venezuelan arid zones. Overall nitrogen isotopic composition (∂15N) did not differ between L. curasoae (15.87‰) and G. longirostris (15.37‰). Although our results suggest that the 2 bats occupy the same trophic position, no conclusive evidence supported this observation. The strong interdependence between these bats and their host CAM plants in northern South America suggests that a disturbance affecting 1 component of the interaction would have a strong effect on the other.
... Flowers are visited by the bats Leptonycteris yerbabuenae, L. nivalis, and Glossophaga longirostris. Other visitors such as insects (hawkmoths, hymenopterans) and birds (Coereba, Icterus, Mimus, and several Trochilidae species) are considered to be opportunistic that do not contribute effectively to pollination (Petit 1995;Nassar et al. 1997). Seed dispersal is driven by the bats Carollia perspicillata, Glossophaga longirostris, Leptonycteris yerbabuenae, and Sturnira lilium, and birds such as Amazona barbadensis, Campylorhynchus griseus, Cardinalis phoenicius, Colinus cristatus, Columba corensis, Coereba flaveola, Elaenia spp., Euphonia laniirostris, Icterus spp., Melanerpes spp., Mimus gilvus, Phaethornis hispidus, Piranga rubra, Pitangus sulphuratus, Pyrocephalus rubinus, Ramphocelus dimidiatus, Sicalis spp., Sporophila nigricollis, Tachyphonus rufus, Thraupis spp., Tyrannus melancholicus, Xiphorhynchus picus, and Zonotrichia capensis (Naranjo et al. 2003;Ruiz et al. 2000;Soriano et al. 1999;Sosa and Soriano 1993;Silvius 1995). ...
This chapter reviews taxonomic, ethnobotanical and ecological aspects of the genus Stenocereus in Mexico. Use, management and domestication of the most relevant species are emphasized.
... Knowledge about the bat fauna of the ABC islands has been mostly based on a small number of publications on fau na inventories (Hummelinck, 1940;Husson, 1960;Bekker, 1996;Smith et al., 2012) and ecological research (Petit, 1995(Petit, , 1997(Petit, , 1998Petit et al., 2006;Simal et al., 2015). Of the three islands, Curaçao has the most detailed information on cave-dwelling bats and caves used as roosts where Petit et al. (2006) monitored species composition and abundance for 12 years (1992)(1993)(1994)(1995)(1996)(1997)(1998)(1999)(2000)(2001)(2002)(2003). ...
Bats play key ecological roles on the islands of Aruba, Bonaire and Curaçao (ABC islands), Caribbean Netherlands; however, most
bat species on these islands are either threatened or their conservation status is unknown. We investigated the use of roosts by caved-welling bats in this insular system to propose conservation measures aimed at their protection. We conducted bi-monthly species
inventories of cave-dwelling bats in 13 of the best-known caves and mines used as day and maternity roosts on the ABC islands. Bats were captured with mist nets and a harp trap (only one cave) placed either inside or at the entrance of the roosts during the first hours (3 to 5 hrs) after sunset. For Aruba and Curaçao, bat monitoring comprised two years of sampling. In the case of Bonaire, depending on the cave, bat monitoring involved one, two or four years of sampling. We identified six species of cave-dwelling bats associated with these roosts, Mormoops megalophylla, Pteronotus davyi, Natalus tumidirostris, Myotis nesopolus, Glossophaga longirostris and Leptonycteris curasoae. All the examined caves and mines were occupied year-round. The two abandoned mines were inhabited exclusively by the nectar-feeding G. longirostris and L. curasoae, whereas caves containing hot chambers were occupied by up to five species of bats, including insect-feeding M. megalophylla, P. davyi, M. nesopolus and N. tumidirostris, and migratory L. curasoae. Nursery roosts occupied by insect-feeding bats were Quadirikiri on Aruba; Orizjan, Pos di watapana and Pos di Antoin on Bonaire; and Raton and Noordkant on Curaçao. Nectar-feeding bats used all the caves and mines examined as day roosts, nursery roosts or both. All the cave-dwelling bats studied had a single annual reproductive period. In the case of insectivorous bats, pregnancy and lactation occurred mainly between July and December, overlapping with the rainy season. For nectar-feeding bats, pregnancy and lactation took place between March and September, overlapping with the flowering and fruiting seasons of
chiropterophilous cacti. Most of the examined bat roosts require protection due to one or more of the following conditions: (1) the
presence of multiple species dependent on hot chambers, (2) their use as nursery roosts, and (3) the presence of large colonies of L. curasoae.
... longirostris) are the only well-known key-stone species of fauna for the terrestrial ecosystem of Bonaire. These two nectar-feeding bats are exclusive pollinators and/or seed dispersal agents of several species of columnar cacti (Cereus repandus, Pilosocereus lanuginosus, Stenocereus griseus) in the region (Nassar et al., 1997;Petit, 1995Petit, , 1997. Columnar cacti not only support nectar-feeding bats in these ecosystems, but they also provide food and water to a broad range of vertebrates and invertebrates, including birds, iguanas, lizards and important pollinating invertebrates like butterflies, bees, and hawkmoths, among others. ...
This report is a study of the special karst features found on the north face of the Middle Terrace on the former plantation Bolivia, in the Island of Bonaire, Caribbean Netherlands. Additionally, the report provides recommendations to protect key natural values in this geological formation.
... Diverse sedimentological aspects of watersheds have been analyzed by several authors, regarding their size, substratum and hydrological regimes [1,2,3,4,5,6]. Soil erosion is sensitive to many factors such as land use, geology, rainfall distribution and intensity, and pedology [7,8,9,4]. The essential role of extreme events on longterm sediment transport is highlighted [10], as well as a wide variability of watershed erosion at spatial and temporal scales [11,12,13,14,15]. ...
The Dehamecha watershed is one of the most degraded basins in Algeria. This basin suffers from strong water erosion, especially during floods, where sediments are transported by the Endja watercourse draining it and depositing them in Beni-Haroun dam. Based on data series provided by the National Water Resources Agency of Constantine concerning the Tassadane gauging station, a correlation is made between two data pairs: suspended material concentrations and liquid flow C-Ql, solid flow and liquid flow Qs-Ql. On a monthly scale, the exponential model is the most suitable for the first correlation and the power model for the second one. Based on these two mathematical models, the quantitative estimation is obtained by identifying the average specific erosion rate over a 30 years’ period, which exceeded 1000 tons / km2.year. The extreme events (floods) have a predominant role in the export of large sediment volumes.
... Several columnar cacti are classified as keystone species that many organisms depend on for survival (Poulin et al. 1994;Petit 1996;Petit and Leon 1996;Valientebanuet et al. 1996;Arizmendi et al. 2002;Valiente-Banuet and Godínez-Á lvarez 2002;Wolf and Martínez del Rio 2003;Drezner 2014). Bats (Petit 1995(Petit , 1998Petit and Leon 1996;Nassar et al. 1997;Arizmendi et al. 2002) and hummingbirds (Fagua and Ackerman 2011) are cacti pollinators and cacti nectar can represent an important portion of their diets (Petit and Leon 1996;Soriano and Ruiz 2002;Valiente-Banuet and Godínez-Á lvarez 2002;Wolf and Martínez del Rio 2003). Although their importance is documented, little research has been conducted on the seven native or endemic Puerto Rican cactus species (see Carrera-Martínez et al. 2015 (Liogier 1994). ...
Tropical dry forests are threatened by invasive species. In Puerto Rican dry forests, two of these invasive species are the Harrisia cactus mealybug Hypogeococcus sp. (HCM), a member of the H. pungens-complex (Hemiptera: Pseudococcidae), and the liana Jasminum fluminense (Oleaceae). Here, we aim to determine the effects of HCM and J. fluminense on the flower and fruit production of Pilosocereus royenii and on the short-term mortality of the native columnar (P. royenii and Stenocereus fimbriatus), semi-epiphytic (Selenicereus trigonus and Leptocereus quadricostatus), and globular (Melocactus intortus) cacti of Puerto Rico. To assess HCM infestation, we created a numerical infestation index with six categories, ranging from uninfested and healthy, to heavily infested cacti (0–5) based on the number and size of tumors. Flower and fruit production of P. royenii was observed at three sites, while the survival of all cactus species was observed at twelve sites for 2 years. Mortality of all cacti species increased with severe HCM infestation. Mortality was highest in M. intortus, and lowest in St. fimbriatus and L. quadricostatus. Mortality of P. royenii was negatively correlated to precipitation, and positively to HCM and liana infestation. Individuals of P. royenii that were heavily infested with both HCM and lianas were more likely to die than healthy cacti only infested with lianas, while P. royenii flower and fruit production was negatively correlated only with HCM infestation. This suggests that J. fluminense becomes a better competitor during dry periods when P. royenii is infested with HCM. While other members of the H. pungens-complex are considered biocontrol agents in places where columnar cacti are not native, this study demonstrates that HCM species found in Puerto Rican dry forests could potentially decrease the biodiversity of these cacti in their native habitats.
... Entre as cactaceae, encontramos desde suculentas adaptadas à seca periódica e de longa duração por meio de extrema suculência (Melocactus, Coleocephalocereus) com tecidos mucilaginosos (Pilosocereus, Micranthocereus) e cutícula espessa (Cereus), até epífitas adaptadas a períodos curtos de seca, mas capazes de sobreviver em situações de extremo sombreamento, como Sabemos pouco a respeito da ecologia das cactaceae no brasil para citar casos específicos, mas ao menos em certas localidades da caatinga, campo rupestre, fisionomias mais secas da floresta Atlântica e na restinga existem comunidades nas quais a perda das cactaceae poderiam certamen-te afetar o fornecimento de importantes serviços ambientais como os recursos energéticos disponíveis para os animais polinizadores e dispersores. Talvez o mais vulnerável dos grupos de animais sejam os morcegos que visitam os cactos colunares para alimentar-se de néctar, pólen e frutos (Zappi, 1994;Ruiz et al., 1997;locatelli et al., 1997;Petit 1999;Aona et al., 2006;Rocha et al., 2007). Em algumas dessas comunidades as cactaceae florescem e frutificam durante a maior parte do ano, representando um recurso alimentar contínuo mesmo quando o resto da vegetação encontra-se dormente sob efeito da estação seca. ...
... En el Norte de Sudamérica los murciélagos glosofaginos Leptonycteris curasoae y Glossophaga longirostris se alimentan principalmente de néctar, polen y frutos de cactáceas columnares de los géneros Stenocereus, Subpilocereus y Pilosocereus, así como polen de agaváceas en el caso de L. curasoae (Soriano et al. 1991, Sosa y Soriano 1993, Petit 1997, Ruiz et al. 1997, Martino et al.1998. Estos murciélagos constituyen los principales agentes polinizadores de las cactáceas columnares presentes en ambientes xerofíticos (Petit 1995, Nassar et al. 1997, estableciendo un sistema mutualístico cactusmurciélago, mientras que su contribución en la dispersión de las semillas de estas plantas parece ser compartida con algunas aves (Rengifo 1997, Naranjo 1998, Soriano et al. 1999. ...
... Entre as cactaceae, encontramos desde suculentas adaptadas à seca periódica e de longa duração por meio de extrema suculência (Melocactus, Coleocephalocereus) com tecidos mucilaginosos (Pilosocereus, Micranthocereus) e cutícula espessa (Cereus), até epífitas adaptadas a períodos curtos de seca, mas capazes de sobreviver em situações de extremo sombreamento, como Sabemos pouco a respeito da ecologia das cactaceae no brasil para citar casos específicos, mas ao menos em certas localidades da caatinga, campo rupestre, fisionomias mais secas da floresta Atlântica e na restinga existem comunidades nas quais a perda das cactaceae poderiam certamen-te afetar o fornecimento de importantes serviços ambientais como os recursos energéticos disponíveis para os animais polinizadores e dispersores. Talvez o mais vulnerável dos grupos de animais sejam os morcegos que visitam os cactos colunares para alimentar-se de néctar, pólen e frutos (Zappi, 1994;Ruiz et al., 1997;locatelli et al., 1997;Petit 1999;Aona et al., 2006;Rocha et al., 2007). Em algumas dessas comunidades as cactaceae florescem e frutificam durante a maior parte do ano, representando um recurso alimentar contínuo mesmo quando o resto da vegetação encontra-se dormente sob efeito da estação seca. ...
... In addition to nectar, it feeds on the pollen and fruit pulp of several plant taxa. Together with Glossophaga longirostris Miller (Phyllostomidae: Glossophaginae), this species is a key pollinator of the most abundant chiropterophilous agaves and columnar cacti in the region, and it is also an important seed dispersal agent of the latter (Nassar 1991;Sosa and Soriano 1993;Petit 1995;Nassar et al. 1997;Fleming and Nassar 2002). It is a highly gregarious species, with several thousand individuals living in densely packed clusters in warm caves and abandoned mines (Cole and Wilson 2006a;J. ...
Of the 3 species comprising the genus Leptonycteris Miller, L. curasoae has been the least studied with respect to its long-distance flights and potential for seasonal migrations. We studied long-distance movements between islands and between islands and the mainland in the Curaçaoan long-nosed bat. We used mark—recapture with periodic sampling and marking of bats in Aruba, Curaçao, Bonaire, and 1 location (Butare) in Falcón State, on the Venezuelan coastline. Between October 2008 and April 2014, we captured a total of 7,518 individuals at 11 sites (Aruba: n = 1,827, Curaçao: 778, Bonaire: 4,128, and Butare: 785). Between 78.3% and 98.0% of the bats captured at each island and mainland were marked, and the overall percentage of recaptured animals across all sampling sites was 8.31% (n = 529). L. curasoae inhabits the 3 islands year-round. On each island, it roosts in several caves, which can be used alternatively by the same individuals. Despite being a resident species, L. curasoae can perform long-distance oversea flights between islands and between islands and the South American mainland. A total of 11 long-distance flights were recorded (2 Bonaire—Aruba, 4 Bonaire—Curaçao, 1 Curaçao—Bonaire, 1 Bonaire—Venezuela, and 3 Aruba-Venezuela). We propose that populations of this species in Aruba, Curaçao, Bonaire, and Falcón State, Venezuela, exchange individuals, and part of the insular populations migrate seasonally southward as a response to cyclical changes in local resource availability and the yearly reproductive regime.
... A number of recent studies have demonstrated that bats are the primary, if not only, pollinators of certain plant species and locations (Cox et al., 1991;Petit, 1995;Cunningham, 1996;Valiente-Banuet et al., 1996;Nassar et al., 1997). Such specialized cases of plant-pollinator relationships are likely to be rare (Waser et al., 1996), but they do indicate that bats are reliable pollinators in these systems. ...
The effectiveness of the common blossom bat (Syconycteris australis) as a pollinator of the rainforest tree Syzygium cormiflorum was assessed by comparing movements, pollen loads, and visitation frequency, with those of birds. The study was carried out in a fragmented rainforest landscape in north Queensland and movements were determined by radio-telemetry. Bats carried 6 times more pollen than birds, but were less frequent visitors to S. cormiflorum, suggesting that the quantity of pollen distributed by the two groups may not differ greatly. However, pollen quality (the geographic/genetic distance moved) may be a more important factor in determining pollinator effectiveness. Bats were very mobile in the fragmented landscape, with home ranges varying from 12 to 1796 ha and often encompassing more than one forest fragment. Bats usually moved along strips of vegetation, but were found to fly up to 5.8 km (mean=1 km) across cleared land. This mobility led to similar numbers of S. australis being caught in small (<50 ha) forest fragments and continuous forest. At the scale of individual trees, bats fed for an average of 1.2 min per tree, compared to 5.0 min for birds. Short foraging times per tree and frequent movements of >200 m should increase the opportunity for movement of pollen between individual trees. Collectively, these observations suggest that S. australis carry pollen of high quality. Although they fly across cleared land, fragmentation may impact bat populations by allowing increased owl predation in open country and by increasing the reliance of bats on flower resources in the agricultural matrix. On the Atherton Tablelands, the latter is provided mostly by cultivated bananas (Musa sp.), which produce nectar but not pollen.
... Observations (Porsche, 1939;Vogel, 1969;Helverson, 1993) and recent experimental evidence suggest that bats and hummingbirds are strongly associated with pollination of columnar cacti (Nassar, 1991;Fleming et al., 1993;Petit, 1995;Fleming et al., 1996;Sahley, 1996;Sahley and Baraybar, 1996;Valiente-Banuet et al., 1997) (Cruden, 1972;Heithau 1974;Bertin, 1982). (Fleming et al., 1996). ...
I examined 4 components of pollination of the organ-pipe cactus, Stenocereus thurberi, by bats and hummingbirds. I quantified amount of pollen deposited per flower visit by bats and hummingbirds on stigmas of conspecifics, estimated amounts of pollen transferred per visit, examined variability in pollinator success within and among flowering seasons of S. thurberi, and determined levels of pollen-mediated gene flow. Both bats and hummingbirds deposit large quantities of pollen on a per visit basis. Pollinator exclusion experiments indicate that proportion of fruits produced by hummingbird pollination was constant in spring 1992 and 1993, but that of bats was significantly greater in 1993 than in 1992. I compared results obtained in spring of 1992 and 1993 with those obtained from a previous 2 year study, and found that, in all 4 years, proportion of fruits produced by hummingbird pollination remained constant, but proportion of bat pollinated fruits varied significantly. During 1993, fruit production attributable to both bats and hummingbirds dropped significantly in late June relative to spring, after peak flowering. Variability in fruit-set by control flowers is likely due to variability in bat pollination events. Paternity exclusion analysis of cactus seeds indicated that most paternal gametes probably came from within 75 m, although substantial amounts of gene flow came from beyond 125 and 150 m for the 2 S. thurberi populations studied.
... Situações intermediárias ocorrem com Pilosocereus catingicola e Brasiliopuntia brasiliensis, ambas com morfologia caulinar especializada para desenvolver-se numa situação florestal durante os estágios iniciais de Sabemos pouco a respeito da ecologia das cactaceae no brasil para citar casos específicos, mas ao menos em certas localidades da caatinga, campo rupestre, fisionomias mais secas da floresta Atlântica e na restinga existem comunidades nas quais a perda das cactaceae poderiam certamen- te afetar o fornecimento de importantes serviços ambientais como os recursos energéticos disponí- veis para os animais polinizadores e dispersores. Talvez o mais vulnerável dos grupos de animais se- jam os morcegos que visitam os cactos colunares para alimentar-se de néctar, pólen e frutos (Zappi, 1994;Ruiz et al., 1997;locatelli et al., 1997;Petit 1999;Aona et al., 2006;Rocha et al., 2007). Em algumas dessas comunidades as cactaceae flores- cem e frutificam durante a maior parte do ano, representando um recurso alimentar contínuo mesmo quando o resto da vegetação encontra-se dormente sob efeito da estação seca. ...
O PAN Cactáceas tem como objetivo promover a conservação efetiva e a redução de risco de extinção de espécies de cactáceas no Brasil. Ele abrange 28 espécies ameaçadas de extinção, bem como estabelece estratégias para proteção de outras consideradas em risco.
O Plano é composto por três metas, com as suas respectivas ações, cuja previsão de implementação está estabelecida em um prazo de cinco anos, com validade até dezembro de 2015.
Série Espécies Ameaçadas n° 24
... In both populations, Pterocereus gaumeri lost immature fruits by abortion and predation. Consequently, plants of (49 and 100%;Petit 1995, Nassar et al. 1997Fleming et al. 1994), and Stenocerew stellatus (71%;Casas et al. 1999). Seed predation played a fundamental role in the low recruitment of new individuals of Pterocereus gaumeri to the population. ...
Se presenta un estudio demográfico de Pterocereus gaumeri, un cactus raro, y endémico columnar de la Península de Yucatán, México. Desde 1997 a 1999, se registró el crecimiento, la sobrevivencia y la fecundidad de indivíduos en dos poblaciones. Se construyeron matrices de proyección basadas en tamaño poblacional para documentar la dinámica de las poblaciones. Se realizaron experimentos de germinación de semillas y establecimiento de plántulas en condiciones naturales, para estimar la tasa de sobrevivencia de semillas y plántulas. Nuestros resultados sugieren que P. gaumeri no se reproduce asexualmente o por crecimiento vegetativo, por lo tanto el crecimiento poblacional depende completamente de la reproducción sexual. El bajo éxito reproductivo, la depredación de semillas y la baja tasa de sobrevivencia parecen ser factores importantes que contribuyen a la rareza de esta especie. La tasa de crecimiento poblacional (λ) varía entre 0.9545 y 1.0316. De acuerdo con los valores de las matriz de elasticidad, la dinámica poblacional de esta especie depende principalmente de la sobrevivencia de los adultos, con valores bajos en fecundidad y sobrevivencia de las categorías de tamaños menores. Nuestros resultados no indican que el tamaño poblacional de P. gaumeri esté decreciendo, sin embargo, el incremento de presion por el cambio de uso de la tierra es uno de los factores más significativos que puede amenazar la continuidad de esta especie.
... A remarkable number of columnar cactus species show anatomical features for bat pollination (chiropterophily), which has been demonstrated by several authors (Nassar et al. 1997, Petit 1995, Valiente-Banuet et al. 1995. Bats and birds are known consumers of cactus fruits in different arid zones in the American continent (Ruiz et al. 1997, Silva 1988, Silvius 1995, Soriano et al. 1991, Sosa 1997, Sosa & Soriano 1992Wendelken & Martin 1988). ...
Effects of seed passage through digestive tracts of principal animal dispersers (bats and birds) on seed germination were investigated for two columnar cactus species, Stenocereus
griseus and Subpilocereus
repandus. In general, seeds ingested showed more rapid germination times and higher overall germination rates than untreated seeds. The bat Glossophaga
longirostris, and the birds Mimus
gilvus and Tachyphonus
rufus seem to be the most efficient cacti dispersers in terms of quality of treatment. The increment of germination speed and particularly the decrease of imbibition time, could favour the probability of germination in dry areas such as arid and semi-arid environments.
... Thus, for a speciose group like bats, efforts to conserve local biodiversity should not focus exclusively on rare species or on locations with the highest species richness, but rather on a combination of habitats and a suite of species, including different guilds (e.g., frugivores, nectarivores, and carnivores) representing the range of variation in the local communities (Chase et al. 2000, Lindenmayer et al. 2002. The high mobility of some bat species has important ecological implications because several plant species depend on them as seed dispersers and pollinators, and under certain conditions, they are the most reliable agents available (Heithaus 1982, Fleming 1988, Cox et al. 1991, Petit 1995, Law & Lean 1999, Medellin & Gaoana 1999. Studies have shown that tree species pollinated by bats and birds have a lower degree of genetic subdivision than those pollinated by less-mobile pollinators (Hamrick & Loveless 1989, Fleming & Sosa 1994. ...
In spite of the important role played by bats in tropical ecosystems, little is known about how they are affected by habitat fragmentation. By using a mark/recapture protocol and radiotelemetry techniques in a naturally fragmented landscape composed of primary forests and forest fragments surrounded by savannas in Alter do Ch (a) over tildeo, Pari State, Brazil, we were able to track the movements of various species of bats, calculate the size of the area used, locate roosts and potential feeding areas, and determine preferred flight routes. We marked 3440 bats belonging to 44 species and recaptured 151 belonging to 14 species. The average distance between extra-site recaptures was 2.2 km. With the exception of bats marked in fragments and recaptured in forests, all other possible inter-habitat recaptures were observed. We selected 23 bats of 8 species for radiotelemetry and the areas used by them varied from 65 to 530 ha. Some species restricted their activity to the vicinity of their roosts, rarely moving more than 500 m away, but others traveled greater distances between roosts and foraging areas. All tracked bats flew over savannas, crossing distances from 0.5 to 2.5 km. Roost location and type varied among species, from individuals roosting alone in the foliage to colonies in buildings. Bats were highly mobile and savannas did not appear to inhibit the movements of some species, suggesting that a persistent biological flow may be maintained among isolated fragments, with bats acting as pollinators and seed dispersers.
... El esfingido, a pesar de haber sido observado sobre las flores de S. griseus, s6lo h e abundante durante la principal tpoca de lluvias (octubre-noviembre). Por otro lado, observaciones hechas en CuraGao (Petit 1995) mostraron una muy baja eficiencia en la po-linizaci6n de esta cacticea. Estas mediciones y observaciones sugieren, que si bien existen otros posibles polinizadores de cactdceas columnares en el irea de estudio, G. longirosrrik juega un papel importante en la polinizaci6n de estas plantas por su abundancia y por estar presente a lo largo de todo el afio. ...
Mutualistic relations between the bat Glossophaga longirostris and columnar cacti were studied in the Andean arid region of La Tatacoa, Huila, Colombia. By means of monthly censuses between August 1993 and July 1994, the diet and reproductive pattern of this bat species was determined. This bat consumed pollen (53%) of cacti and of Helicteris baruensis (Sterculiaceae) and fruits (41%) of the columnar cactus Stenocereus griseus and, in lower quantities, of Muntingia calabura (Elaeocarpaceae) and Pilosocereus sp. (Cactaceae). Pollen appeared in feces and/or pelage of G. longirostris throughout the year, being more frequent during the dry season. Seeds appeared in the feces during the rainy season. The seasonal variations in diet were correlated with the availability of resources in the area and do not appear to reflect a dietary preference on the part of G. longirostris. This bat had two reproductive periods. The presence of lactating females coincided with the two rainy seasons and the months of highest fruit production of S. griseus. These results are not consistent with those reported for the Andean arid region of Lagunillas, Merida, Venezuela. In that region, G. longirostris depends for its diet and reproduction on three columnar cactus species (S. griseus, Subpilocereus repandus and Pilosocereus tillianus). The differences found in the diet and periods of reproductive of these two populations of G. longirostris, may reflect differences in the temporal and spatial distribution of food resources. The mutualistic relation between G. longirostris and columnar cacti, specially with S. griseus appear to be tightly interdependent.
... Leptonycteris curasoae has long been recognized as one of the principal pollinators of saguaro and organ pipe cacti (Alcorn et al. 1961;McGregor et al. 1962) and agaves (Howell and Hodgkin 1976) and since these first descriptions many other species of cacti and agaves have been identified that are principally pollinated by this species (Howell 1979;Howell and Roth 1981;Eguiarte et al. 1987;Howell and Hartl 1989;Petit 1995;Fleming et al. 1996;Nassar et al. 1997;Casas et al. 1999). Our study demonstrates the importance of this species as a potential pollinator of several bombacaceous species and the principal pollinator of C. grandiflora (Stoner, unpublished data). ...
We estimate fluctuations in population size and sex ratio, documentbreeding behavior and reproduction, and determine the diet of a population ofthe lesser long-nosed bat, Leptonycteris curasoae, in anisland cave in Chamela Bay, Jalisco, Mexico, with monthly sampling during anannual cycle (October 1999–October 2000). Based on the area of thecave''s ceiling and wall covered with L. curasoae inrelation to the potential roost area without them, in 1999 the abundanceincreased from 80% in October to 100% in November and December. In 2000 thepopulation decreased to 80% in January, 50% in February, 30% in March, 20% inApril, 10% in May, 5% in June and July, and less than 1% in August. Thepopulation rapidly increased to 60% in September and to 80% in October.Throughout the year there were significantly more males than females; however,there was significant heterogeneity over months. In September–Novemberthere were more females, but in December–August there were more malespresent. The majority of pregnant and lactating females were observed fromDecember to March and in July, while males were reproductive fromSeptember–January and in May–June. Breeding activity was observed inthe cave in November–December. Twenty-six species of plants were consumedduring the year, based on pollen identification from fecal samples. Bombacaceousspecies were the most important component of the diet from January to May andCactaceae were most important in June–September. Peak abundance and reproductive activitycoincided with peak flower resource availability, which occurred between Octoberand January and in June–July. The year-round presence and reproductiveactivity of L. curasoae at this site throughout the yeardemonstrate that many individuals are annual residents in this area and indicatethe importance of this roosting site. In order to develop a successfulconservation program for L. curasoae, in addition toprotecting migratory corridors and northern maternity roosts, it is equallyimportant to identify and protect areas that function as breeding colonies andyear-round sanctuaries for resident populations in the south.
... Pollinator effectiveness can be assessed with various measures, including pollen load carried and transferred, pollinator visits (relative abundance, visitation timing and duration), pollen viability and quality, probability of contact with stigma and anthers, fruit set, seed set, seed viability and germinability, and seed or fruit characteristics such as size, mass and number (e.g. Spears Jr 1983; Young 1988; Fishbein and Venable 1996; Petit 1998; Ivey et al. 2003; Sahli and Conner 2007; Theiss et al. 2007). Because the pollen of C. behrii is aggregated, pollination is achieved by a single visit by a pollinator. ...
Caladenia behrii Schltdl. (Orchidaceae) (syn. Arachnorchis behrii) is a sexually deceptive, endangered orchid that produces aggregated pollen as pollinia. It is pollinated by a thynnine wasp, and may also be pollinated incidentally by other insects. Pollinator effectiveness may depend on the number of pollinia that pollinators carry and deposit, and on whether they mediate cross-pollination or self-pollination. To understand the role of pollinators and guide conservation programs, we determined the effect of pollen load (one pollinium v. two pollinia) and self-pollination on seed number, seed (embryo) size and germination at 35 days. We also examined the effect of plant size on seed size and seed number. By using partial correlations with leaf width, seed size, seed number, capsule volume and stem length, we found that leaf width was a good predictor for seed number, and that seed size was not correlated with any of the variables examined. Flowers pollinated with one pollinium and two pollinia did not produce seeds that differed in size or number. Cross-pollinated flowers produced fewer but larger seeds, which germinated faster than did seeds from self-pollinated flowers. We conclude that seed production in the field may be estimated from leaf size, that pollinators carrying one pollinium are as effective as those carrying two pollinia and that selfing affects germination negatively, partly because of the smaller size of selfed seeds. Conservation programs aiming to perform hand-pollination of this species should use crossing with a single pollinium.
This report is a study of the natural values of the entire area known as Lima on the Island of Bonaire, Caribbean Netherlands. It aims to give recommendations to the developer and legislators to preserve these values while carrying out potential development projects (residential, recreational, touristic, etc.) in the area.
New World bats play a significant role in ecosystem functioning and are imperative for maintaining environmental services. Nevertheless, human-caused environmental changes are jeopardizing bat communities, which results in the loss of functional roles provided by them. It is important, therefore, to assess ecological processes performed by bats in the Neotropics to define priorities in further research for better conservation planning. In this systematic review, I identify general trends, advances, bias, and knowledge gaps in bat-mediated ecological processes across Neotropical ecosystems. I conducted an extensive search on Google scholar, Scopus, Web of science, and Bat Eco–Interactions Database resulting in 538 references, of which 185 papers were included in the review. The papers were published in 76 peer-reviewed journals, with the highest peak between 2006-2010. From the six biomes recorded, Moist broadleaf tropical forest was the most researched, contrary to Montane biomes (<2000 m), where few studies have been conducted. Seed dispersal was the process with more studies (44%), followed by pollination (38%), nutrient cycling (10%) and arthropod suppression (8%). Seed dispersal and pollination displayed large bias on specific bat-plant systems and ecoregions, thus being important to explore other bat and plant species as well as other ecosystems. Arthropod suppression and nutrient cycling were largely overlooked despite to constitute essential functions in ecosystem resilience; particularly, more research is needed to know cascading effects on plant fitness in different agroforestry systems, but also is key the understanding of how bats can be pivotal mobile links in terrestrial ecosystems and cave environments. I highlight the importance to consider bats with multiple roles and functional trait-based approach to gain a comprehensive understanding of their functionality. Bat extirpations are likely to affect their ecological roles, therefore, mitigating major threats of bats are urgently needed to sustain ecosystem integrity in the Neotropics. Even though functional studies have increased in the last two decades, several aspects of bat roles are still obscured and is necessary to keep evaluating their ecological and economic importance to provide useful information for major decision-makings in Neotropical ecosystems' conservation.
In view of their ecological importance and the abundance of threats on a developing Caribbean island, we surveyed the bats of Curaçao, Netherlands Antilles, and examined changes in the populations of seven threatened species over a decade, using previously published data as a baseline for comparison. The most important caves for bats (in terms of species representation and reproduction) were visited yearly, and monthly in 2001. Noctilio leporinus still occurs on the island, but does not appear to be numerous (six observed in 2003). We captured Myotis nesopolus nesopolus, but its roosting sites remain unknown. Leptonycteris curasoae curasoae numbers varied greatly, even within a year, and it may travel to and from other islands and Venezuela. Overall, however, the population of this species on Curaçao seems to be declining (1000 in 1993 and 625 in 2003); the disappearance of this pollinator could have severe consequences for the Curaçao ecosystem. Mormoops megalophylla intermedia is declining as well; in 2003, we counted 403 individuals including 75 pups, from 500 to 600 adults in the 10 previous years, representing a 25–30% decline in 1 year. We estimated the population of Natalus tumidirostris to be 890 in 2003. We also found a group of 60 Pteronotus davyi in Kueba di Ratón in 2003. Glossophaga longirostris elongata (1417 individuals counted) is the only species for which our data indicate relative stability over 10 years; L. curasoae and Mor. megalophylla are declining and other species must be monitored closely. Most caves are disturbed; four major caves require attention for the conservation of the most fragile species. Without immediate attention, Mor. megalophylla, in particular, risks imminent extinction. Despite problems associated with bat counts on Curaçao, it is clear that regular surveys are crucial to understand bat populations and their fluctuations in caves, and to allow management responses to declines, particularly for areas undergoing rapid urbanization.
Two sympatric species of columnar cacti on Curaçao, Netherlands Antilles, share bat pollinators, overlap in flowering phenology,
and are floral homologues. Leptonycteris curasoae curasoae and Glossophaga longirostris elongata (Chiroptera: Glossophaginae) visit flowers of Stenocereus (syn. Ritterocereus) griseus and Subpilocereus (syn. Cereus) repandus on the same nights; these visits may promote interference competition between cactus species. I studied the effect of heterospecific
(mixed) pollen loads on fruit and seed set, fruit and seed size and mass, germinated seeds at 5weeks, and seedling survival
at 7months in relation to hand pollination with intraspecific pollen and natural pollination. Hand pollination seemed to
limit pollen loads available for pollination. Under these conditions, natural pollination tended to produce the most fruits
and seeds, and the largest fruits (but lightest seeds); mixed pollination was the least effective treatment (fruit set was
significantly greater for St. griseus in natural than mixed pollination; fruit volume was greater in natural than mixed pollination for S. repandus, and seed number and fruit mass were larger in intraspecific than in mixed pollination). Aspects of natural pollination,
possibly repeated visits, compensated for the negative impact of interspecific pollen loads under pollen limitation, with
positive impacts on the carrying capacity of cacti for frugivores. Seed mass from natural pollination was negatively correlated
with seed number only for St. griseus. Germination success was not correlated with seed mass, but seedling survival at 7months was for S. repandus. The two species do not seem to compete through pollen interference when pollinator visits are relatively frequent.
KeywordsBat pollination–Carrying capacity–Coexistence in mutualism–Heterospecific pollen–Pollinator sharing–Seed germination
The phenological response by three sympatric species of columnar cacti of the semi-arid island of Curaçao (Stenocereus griseus, Subpilocereus repandus, and Pilosocereus lanuginosus) to recent rainfall was investigated during 21 months. Rainfall is the climatic cue most likely to affect bud formation on Curaçao, and each species of cactus responded differently to it. Pilosocereus lanuginosus started budding immediately after rainfall, whereas Stenocereus griseus responded negatively with abortions and cessation of bud production within 2–3 weeks after rain. Subpilocereus repandus showed no response to rain within one month. Despite a long period of temporal overlap (81% overlap) between the budding/flowering activity of Subpilocereus repandus and that of Stenocereus griseus, buds and/or flowers on Stenocereus griseus appeared more than a month earlier than on Subpilocereus repandus.The effect of plant size on phenology and how anthropogenic disturbance may affect cactus resource availability to nectar-feeders and frugivores were also examined. The larger the individual tree within a species, the more flowers were produced and the earlier the tree started to flower. Thus, the indiscriminate removal of columnar cacti for urban development can drastically affect the timing and availability of resources to threatened pollinators and other nectar-feeders, as well as to frugivores and omnivores.
Chiropterophillous and ornithophillous characteristics can form part of a single reproductive strategy in plants that have flowers with diurnal and nocturnal anthesis. This broader pollination strategy can ensure seed set when pollinators are scarce or unpredictable. This appears to be true of hummingbirds, which presumably pollinate Marginatocereus marginatus, a columnar cactus with red nocturnal and diurnal flowers growing as part of dense bat-pollinated columnar cacti forests in arid regions of central Mexico. The aim of this study was to study the floral biology of M. marginatus, and evaluate the effectiveness of nocturnal vs. diurnal pollinators and the contribution of each pollinator group to overall plant fitness.
Individual flower buds were marked and followed to evaluate flower phenology and anthesis time. Flowers and nectar production were measured. An exclusion experiment was conducted to measure the relative contribution of nocturnal and diurnal pollinators to seed set.
Marginatocereus marginatus has red hermaphroditic flowers with nocturnal and diurnal anthesis. The plant cannot produce seeds by selfing and was pollinated during the day by hummingbirds and during the night by bats, demonstrating that both pollinator groups were important for plant reproduction. Strong pollen limitation was found in the absence of one of the pollinator guilds.
Marginatocereus marginatus has an open pollination system in which both diurnal and nocturnal pollinators are needed to set seeds. This represents a fail-safe pollination system that can ensure both pollination, in a situation of low abundance of one of the pollinator groups (hummingbirds), and high competition for nocturnal pollinators with other columnar cacti that bloom synchronously with M. marginatus in the Tehuacan Valley, Mexico.
In a cloud forest at Monteverde, Costa Rica, the authors examined pollen loads received by self-compatible flowers of 2 pairs of plant species pollinated by hummingbirds: Hansteinia blepharorachis and Razisea spicata (Acanthaceae), and Besleria triflora and Drymonia rubra (Gesneriaceae). Each pair consisted of one species pollinated by short-billed hummingbirds and a related species pollinated by long-billed hummingbirds. There were no consistent effects of floral neighborhoods on numbers of heterospecific grains deposited on stigmas. In none of the 12 sampling runs did increases in absolute densities of neighboring heterospecific flowers adversely affect pollination. However, in 2 runs, loads of conspecific grains increased with increases in the absolute density of neighboring conspecific flowers, and/or (in 3 runs) with increases in their relative density (proportion of conspecifics among neighboring flowers). These runs all involved short-flowered species, but half the sampling runs, even of short-flowered species, failed to show any density-dependent effects from neighboring flowers pollinated by the same hummingbirds. -from Authors
Seed mass in wild radius (Raphanus raphanistrum) varies up to sixfold within single fruits. The impact of such variation on subsequent growth and fecundity was studied. Seeds from single fruits were used to minimize genetic differences among individuals. Weighed seeds were planted close together in a disturbed area typical of Raphanus habitats. Large seeds (>6 mg) were more likely to emerge as seedlings than were small seeds (<4 mg). Seed size had no effect on emergence time. Seedlings from large seeds grew more rapidly and produced more flowers than did those from related smaller seeds. Results from the field experiment contrasted with those obtained in greenhouse growth studies, where seed size had no significant effect on final plant size. This study points out two factors that have led to inconsistent results in previous studies of seed size and seedling success: (1) differences in the timing of growth measurements, and (2) the presence or absence of competitive inequities among neighbors within the experimental design.
Describes striking spatiotemporal variation in the antguard and pollinator mutualist assemblages of Calathea ovandensis (Marantaceae). Fifteen different ant taxa (in 5 subfamilies) and 5 pollinator taxa (4 euglossine bees and 1 anthophorid bee) were associated with the plants in Veracruz, Mexico. Mean number of taxa per site per year was 6.8 for ants and 3.6 for pollinators. The ant assemblage varied more than the pollinator assemblage, particularly spatially. The ant assemblage varied more through space than through time (means of the proportional similarities for pairwise comparisons of assemblages were 0.37 and 0.51, respectively), while the pollinator assemblage varied equally through space and time (means of the proportional similarities were 0.53 and 0.50, respectively). For individual taxa of both assemblages, the coefficient of variation in relative abundance was large (>75%) for most spatial and temporal comparisons. In each assemblage there was a single taxon that was the least variable, in both time and space, in its relative abundance. Results, coupled with previous findings of significant variation among mutualist taxa in the magnitude of their beneficial effects, indicate that plants may be subject to highly variable selection by their mutualist assemblages. The most beneficial antguard was consistently rare; the most beneficial pollinator was abundant in one site-year but rare or absent in most site-years. The taxon that was consistently abundant was not an efficient pollinator. Evolutionary specialization of plants on particular animals may be constrained by lack of constancy in the relative abundance of animals and the opportunity for specialization may differ greatly between interactions due to divergent patterns of constancy, rarity and quality. -from Authors
Seed production of a flower depends both on the quantity of pollen received and on its "quality" as manifested in rates of germination, ovule fertilization, and seed maturation. Disentangling effects of these two factors is complicated by the fact that seed set is a decelerating function of pollen quantity. One potential element of quality is the genetic similarity of pollen donor and recipient. In ten experiments with Delphinium nelsonii, seed set varied with outcrossing distance, a correlate of genetic similarity. Over all experiments, a 10-m distance significantly (P < .02) outperformed shorter and longer distances by 23-33%, suggesting quality differences. To explore this possibility, we fit decelerating negative-exponential regressions to relationships among stigma pollen load, pollen tube number reaching the ovary, and seed set in a subset of experiments having 1-, 10-, and 100-m treatments. Regression parameters suggested that 10-m pollen is most efficient at producing tubes and seeds, and analysis of residuals from pooled regressions (a nonlinear ANCOVA) showed that 10-m residuals were most positive. The latter effect was significant for pollen load-seed set relationships (P = .009, five experimental replicates) and pollen tube-seed set relationships (P = .021, two replicates), but not pollen load-pollen tube relationships (P = .128, three replicates). These results illustrate the utility of nonlinear regression in distinguishing pollen quantity and quality. They reinforce the conclusion that outcrossing distance affects pollen quality in D. nelsonii, and that an "optimal outcrossing distance" between 1 and 100 m maximizes seed set on average in pollinations using one donor per carpel. Insofar as quality differences persist in natural pollen mixtures that arrive on stigmas, outcrossing distance should affect reproductive success through both paternal and maternal sexual functions.
We measured flight speeds of the nectar-feeding bat, Leptonycteris curasoae, during their nightly commuting flights of 25-30 km. We estimated mechanical power outputs for the flights by using an aerodynamic model and tested predicted flight speeds generated by the model against actual flight speeds observed. Bats flew an average of 27.2 km during one-way commutes to their foraging areas at a mean air speed of 8.2 m/s. Flight speeds observed in bats making commuting flights conformed to predictions generated by aerodynamic theory, and were similar to those previously reported for birds. We suggest that certain morphological attributes exhibited by L. curasoae, such as a relatively large body size and high wing loading, may be adaptations for flying long distances in desert habitats.
We studied the relative effectiveness of different pollinators of Spathiphyllumfriedrichsthalii Schott for 15 months on Barro Colorado Island, Panama. Pollen-foraging stingless bees (Apidae: Trigona) made 87% of floral visits. Experiments showed that these bees pollinate flowers, and correlations of fruit- and seed-set with visitation frequencies and floral contact times suggested that they were responsible for the majority of seeds produced. Fifteen species of fragranceforaging, male euglossine bees (Apidae: Euglossini) collectively accounted for a small portion of seed-set in fewer than 27% of the inflorescences. Neocorynura (Halictidae) were pollen thieves and were unimportant as pollinators. We propose that euglossine and stingless bees differentially influence outcrossing rates and the evolution of floral traits of S. friedrichsthalii. behavior of male euglossines should allow for more long-distance pollen flow whereas stingless bees are likely to promote nearneighbor and geitonogamous pollinations. We discuss why the prolonged male phase of anthesis in this protogynous species may be maintained through pollination by stingless bees rather than male euglossines. Furthermore, although the floral fragrance is attractive to many species of male euglossines, it attracts few individuals. This condition may represent an intermediate step in the evolution of predominant pollination by male euglossines.
In a series of plant-pollinator and plant-seed disperser systems, as the number of species in the mutualistic system increases, the absolute number of interactions established increases, but connectance decreases exponentially. A given increase in diversity adds twice the number of interactions to dispersal systems as to pollination systems, suggesting a higher global specificity of the latter. For seed-dispersal systems involving frugivorous birds, mutual dependence values are strongly skewed toward the low end and illustrate generally strong asymmetries in mutualistic interactions. Coadaptation may originate from a process of species sorting without the necessity of genetic (coevolved) changes. Asymmetrical interactions and the prevalence of weak relations can provide pathways for rare species to persist and alternative routes for system responses to perturbations. -from Author
Initial seed set and fruit set were pollen-limited in a Costa Rican population of Passiflora vitifolia, a self-incompatible species with 200–350 ovules per flower. Pollination intensity was measured by counting the number of allogamous pollen grains on stigmas of the large one-day flowers. Hand-pollinations demonstrated that 25–50 pollen grains are required for fruit set, and >450 are needed for maximum seed set, with a pollen:seed ratio of about 1.6:1.0. Hummingbirds (Phaethornis superciliosus) delivered sufficient allogamous pollen for maximum seed set to only 28% of the flowers examined. Naturally pollinated flowers yielded fewer fruits and fewer seeds per fruit than those pollinated by hand. Most pollen transferred by humming-birds was self-incompatible; emasculated flowers yielded higher seed set than flowers with intact anthers. Visitation rates did not provide a good index of effective pollination.
There were significant differences in ovule number, maximum seed set, and maximum per cent seed set among individual vines. More than half of an individual's flowers failed to set fruit, whether pollinated by birds or by hand. In this population, maximum reproductive potential may be limited by maternal resources for fruit development, but seed set varies with pollination intensity. Pollen-limited seed set may be a disadvantage of self-incompatibility, especially in species with many-seeded fruits.
We conducted a greenhouse study of the effects of initial seed mass on seedling characteristics in a Panamanian population of Virola surinamensis, a canopy tree in which mean seed mass of different individuals ranges from 1.34 to 4.04g. The system is of particular interest because birds preferentially eat fruits of small-seeded plants, leaving seedlings of large-seeded individuals under conditions of potentially severe sibling competition (Howe and Vande Kerckhove 1980).
Effects of differences of mean seed mass between trees are explored using an analysis of variance, while effects of seed-mass variation within crops are demonstrated with a regression analysis. A two-way analysis of variance decisively shows effects of parental source and light condition on seedling height, leaf length, and dry shoot mass (all P<0.0001). A posteriori tests show that differences in seedling characteristics reflect differences in initial seed mass, with especially strong differences apparent in shoot mass. Regression of seedling characteristics on initial seed mass shows that variation of seed size within a crop is sufficient to influence shoot mass at 15 weeks (P<0.0001).
Effects of size differences of seeds that land adjacent to each other, either under the parent or in monkey droppings, are documented with growth of pairs of seedlings in pots. Differences in shoot height and mass at 15 weeks are evident when seeds of average size differ by only 0.2 g, and dramatic differences are evident when paired seeds differ by an average of 1.5 g. Seedlings grow more when isolated than when planted with conspecifics.
These experimental results offer indirect support for the hypothesis that small-seeded Virola parents secure an advantage in reproduction through differential dispersal, while large-seeded plants produce more competitive seedlings under their own crowns — an advantage most likely to be of importance when frugivores are scarce.
The unusual floral biology of a neotropical herb provided an opportunity to determine that floral visitors varied significantly in their ability to effect fruit-set. Pollination efficiency and visitation frequency varied among Hymenoptera (five taxa), which were responsible for 99 percent of all fruits set. Lepidoptera (four taxa) were common visitors but poor pollinators. These results indicate that flower visitors vary in their beneficial effects on plants, fulfilling one of the primary conditions required for the specialization of plants on pollinators.
Estimated the magnitude of phenotypic selection in each of 3 yr on the corolla length of flowers produced by Calathea ovandensis (Marantaceae). A major focus was to determine whether variation among pollinators in pollination efficiency, coupled with the striking temporal variation observed in the pollinator community of Calathea, could promote temporal variation in the direction and magnitude of phenotypic selection. -from Authors
Dieffenbachia longispatha is pollinated by scarab beetles (Cyclocephala spp. and Erioscelis sp.) at the La Selva Biological Station, Costa Rica. The 3 most abundant beetle species differed in abundance, recapture rates, pollen loads carried, and behavior at inflorescences, yet the effect of a single visit on fruit-set of D. longispatha (the "pollinator effectiveness' of each species) did not vary. Use of common indices of pollinator contribution to seed set, such as pollinator abundance and the number of seeds produced as a result of a single visit, would lead to erroneous conclusions if applied to Dieffenbachia and its beetle pollinators, or to other pollination systems where there is cumulative floral damage with increasing visitation frequencies. -from Authors
Linanthus bicolor, a facultatively autogamous California grassland annual, is visited at Jasper Ridge Biological Preserve primarily by bee flies (Bombylius spp.), whose period of flight activity is seasonally limited. I observed seasonal patterns of flowering plant density, pollinator visitation rate, and pollinator foraging movements within and between plants in two neighboring L. bicolor populations which differed by two weeks in the timing of peak flowering. The earlier population passed flowering peak before the period of major bee fly activity; consequently only 7.5% of its flowers were visited and had the chance to outcross. In contrast, in the later population, blooming synchronously with peak bee fly activity, 88.3% of the flowers had the opportunity to outcross. Bee fly movement patterns within plants did not change through the flowering season in either population. Flight distances between plants increased significantly, however, as the density of plants in flower declined through the season. Neighborhood area as estimated from pollinator flight distances on a given date could be accurately predicted by regression on the inverse of flowering plant density. I used this relationship to investigate the potential effects of the timing of pollinator visitation and flowering phenology curve shape on neighborhood structure, by calculating neighborhood area and size in the two populations, varying hypothetical conditions of timing and duration of pollinator visitation. I found that a few long-distance pollinator movements early or late in the season, during periods of low flowering plant density, could greatly increase the potential for gene dispersal in a population. This effect was more pronounced in the earlier L. bicolor population, which had a more leptokurtic flowering phenology curve. Temporal patterns of pollinator visitation and the timing and shape of flowering phenology curves may have an important impact on the genetic structure of plant populations.
Catalpa speciosa regularly initiates more fruits than it matures. Most of the fruits that fail to mature are abscised from 2-5 wk after the flowering period. Catalpa speciosa has a host-specific herbivore, Ceratomia cactic (Sphingidae), which severely defoliates some branches while causing little or no damage to leaves of other branches. The pattern of fruit abscission was examined in relation to the principal herbivore. Field observations and experiments show: (1) the larger the infructescence, the higher the probability that a given fruit will abort; (2) branches that have experienced simulated herbivory have significantly more abortions than control branches;(3) if one fruit is aborted from an infructescence, the remaining fruits have a higher probability of maturing; (4) fruits accumulate <10% of their mature dry weight and total protein during the 1st 5 wk of growth and the remaining 90% in the next 4 wk (after the period of abortion). These data suggest that (1) each branch supplies the energy necessary to mature the fruits that it hears, (2) environmental stress, especially herbivory, reduces the resources available for fruit production, (3) fruit abortion is a response to limited resources, and (4) the pattern of fruit growth reduces the @`cost@' of abortion. The overall pattern of fruit reduction is interpreted as an adaptive trade-off between seed number and seed quality which permits the parent plant to match fruit production with available resources.
We estimated the population sizes of the three species of columnar cacti that grow on the island of Curaçao using ground and aerial transects, and we examined the island’s carrying capacity for two species of nectar-feeding bats that depend on nectar from the flowers of these cacti. We calculated carrying capacity based on the daily availability of mature flowers between January and December 1993 and the field energy requirements of bats as estimated from an equation for eutherian mammals (low estimate) and one for passerine birds (high estimate) based on body mass. Additional energy requirements of pregnancy and lactation were taken into account. We estimated that 461,172 columnar cacti were present on Curaçao (38% Subpilocereus repandus, 51% Stenocereus griseus, and 11% Pilosocereus lanuginosus). May through September are the critical months when bats rely most heavily on cactus for food. July 1993 was a bottleneck with the smallest number of mature flowers per day. July and August were months of greatest energy demand because females were lactating. We estimate that the carrying capacity for Glossophaga longirostris in July, when the bat (Leptonycteris curasoae) population was 900, was near 1200, an estimate that fits the observed population size of nectar-feeding bats on the island. We suggest that the extensive removal of native vegetation occurring on Curaçao be strictly regulated because further destruction of the cacti will result in a decrease and potential loss of the already low populations of nectar-feeding bats.
We examined the potential for exploitation competition by differential attractiveness in two sympatric species of columnar cacti on Curaçao, Netherlands Antilles. Stenocereus griseus and Subpiloccreus repandus have temporally overlapping flowering phenologies and share pollinators. We examined nectar volume, energy contents, and sugar ratios for the entire night and at two-hour intervals in both cactus species. Except for a burst in nectar volume and sugar concentration by Subpilocereus repandus during the first two hours of anthesis, nectar secretion patterns, energy contents, and sugar ratios (70% hexose) were similar for the two species. The standing crops of nectar in both species were kept very low by bat pollinators. We suggest that the potential for exploitation competition between Stenocereus griscus and Subpilocereus repandus is currently very low on Curapo.
In order to examine the relationships among the size of the pollen load, the number of seeds per fruit, the probability of fruit maturation, and offspring quality, we experimentally varied, by hand-pollinations, the number of pollen grains deposited onto stigmas of the common zucchini squash (Cucurbita pepo). We found that differences in the size of the pollen load (low, medium, and high) translate into significant differences in the number of seeds per fruit; moreover, fruits with high seed numbers are more likely to mature than fruits with medium or low seed numbers when the size of the pollen load is varied among flowers on an individual plant. In addition, a controlled greenhouse study revealed that offspring produced by high pollen loads germinate and emerge more rapidly and have more leaves, a greater stem circumference, and more dry biomass at 30 days after emergence than do offspring produced by low pollen loads. These studies indicate that progeny resulting from intense pollen-tube competition (high pollen loads) are more vigorous than progeny produced under conditions of little or no pollen competition (low pollen loads) and that zucchini can, as Lee (1984) hypothesized, improve the average quality of its seed crop by selectively aborting fruits on the basis of seed number.
Advantages of conspecific associations are discussed for pollinating bats and their host plants. Bats forage in cohesive, but structureless, flocks which search more efficiently and exploit plant patches more thoroughly than would individuals. Communal feeding allows intermittent communal roosting which affords more efficient digestion. By following "lead" bats to new plants without individually confirming resource depletion, all bats save energy. There is also a savings in echolocation energy since only leading bats use sonar. Caloric allotments to various activities are presented. Leptonycteris uses a disproportionate amount of energy in a short foraging period. Individual foraging energetics depend on characteristics of the flock. A model is given for the determination of maximum flock size. Symbiont agaves ensure pollen transfer by steeply declining nocturnal nectar flow. The evolution of the association is discussed, with speculations on advantages of grouping for bats and plants prior to mutualistic interactions. The flexibility in the system is mentioned as a safety factor reducing the destabilizing effect of one-to-one obligate interactions.
Five hypotheses explaining the low fruit-to-flower ratios in self-incompatible hermaphroditic plants are tested for Agave mckelveyana. Results from pruning, bagging, and hand-pollination experiments indicate that "excess" flowers (i.e., flowers that fail to produce mature fruits) do not contribute to female fitness (i.e., fruit or seed production). These flowers are aborted regardless of their pollination history. Additional data on nectar production imply that these flowers act as pollen donors and contribute to male fitness.
The bat population of the island of Curaçao, Netherlands Antilles, was surveyed in 1992 and 1993. The 1993 survey concentrated mostly on caves, which were found to host most of the bats. Glossophaga longirostris elongata was the most abundant species with fewer than 2000 individuals encountered. However, this species may also be found in small groups in buildings and caves that were not censused. More critical is the status of the other six species found on the island: Leptonycteris curasoae (800–1000), Mormoops megalophylla intermedia (570–650), Natalus tumidirostris (50–60), and three species for which the number of individuals is unknown and probably low: Myotis nesopolus, Pteronotus davyi and Noctilio leporinus. Three caves contain all of the above species, except N. leporinus, and should be actively protected. Two species expected to be present on Curaçao, Artibeus jamaicensis and Molossus pygmaeus, were not found. The apparent decrease in bat numbers this century is likely a result of uncontrolled cave disturbance and removal of resources through development. I propose that all species be considered endangered on the island of Curaçao, except for Glossophaga longirostris, which is threatened.
Fruit-set values for 447 species of plants were examined for variations due to compatibility, breeding system, life form, latitude, type of fruit, and type of pollination. Results indicate significant differences between self-compatible and self-incompatible species in terms of 1) average fruit-set and 2) the effect of the independent variables. Breeding system, life form, and latitude were the only significant independent variables for self-incompatible species; fruit type and latitude were found to be significant for self-compatible plants. Selective-abortion and bet-hedging hypotheses may be important factors contributing to the low fruit-set in self-incompatible plants, while the male-function hypothesis may explain the lower fruit-flower ratios in hermaphrodites. -from Author
Large pollen loads were more likely to initiate fruit production than small pollen loads, and the former fruits contained more seeds and a greater total seed mass. No further increases in seed number or mass occurred for pollen loads >4000 grains. Effects of pollen donor were generally larger than effects of pollen load, and fruit production from small loads of pollen from one donor were sometimes equal to fruit production from larger pollen loads from another donor. The ratio of pollen grains deposited to resultant seeds increased with pollen load. Seeds from heavy pollinations emerged better than seeds from light pollinations, but did not differ in speed of germination or in the performance of seedlings up to 126 days. Emergence differences are probably due to differing intensities of pollen tube competition. -from Author
Studied the interaction between Greya politella (Lepidoptera: Prodoxidae) and Lithophragma parviflorum (Saxifragaceae) to evaluate the effect on seed output of a pollinating seed parasite against a background of co-pollinators. Flowers were visited and pollinated mostly by bombyliid flies, solitary bees, and G. politella. Bombyliid flies alone composed 68-88% of visits recorded over two yr. Although both male and female G. politella visited the flowers and probed for nectar, thereby passively transferring to the stigma pollen adhering to the abdomen. Visitation to flowers by all pollinators averaged 0.3-1.9 visits/h during daylight hours. Consequently, most flowers were visited multiple times during the several days that stigmas were receptive and 77% of the flowers tagged during the four yr had some developing seeds. Pollination did not depend upon visitation by G. politella. Flowers receiving G. politella eggs had the same probability of producing some seed and the same mean number of developing seeds as flowers visited only by other insects. Most flowers received the eggs of only one G. politella female, and larvae ate 15-27% of the developing seeds. Overall, G. politella females have the potential to be mutualistic with L. parviflorum; they are effective pollinators, generally visit most plants and about half the flowers in the population, and impose a fairly small cost on seed output. Nonetheless, the abundant and effective co-pollinators, which do not eat the developing seeds, swamp Greya's mutualistic effects. Under the current conditions at Granite Point, Washington, the relationship between G. politella and L. parviflorum may be mostly commensalistic. -from Authors
The foraging behavior of butterflies and bumblebees is compared on the same populations of three Senecio species. While bumblebees typically fly near-neighbor distances, resulting in very localized pollen dispersal, butterflies frequently bypass nearby plants, flying significantly greater distances between plants. Bumblebees visit significantly more heads per plant and significantly more plants per foraging bout. The flight distance distribution data are used to calculate neighborhood size and area, in the sense of Wright's isolation-by-distance model, for the observed populations under hypothetical conditions of exclusive butterfly or exclusive bumblebee pollination. It is predicted that small neighborhood sizes will typically be found in plant populations specializing on bumblebee pollination, whereas butterfly-pollinated populations will have much larger neighborhood sizes; bumblebee-pollinated plants will therefore have greater potential for local genetic differentiation. These differences in neighborhood characteristics may be augmented if plants are self-compatible or if pollen carryover occurs, since bumblebees make a higher proportion of intraplant flights. The addition of a small amount of butterfly pollination can increase gene dispersal in a plant population sufficiently to greatly reduce genetic drift and microgeographic adaptive differentiation.
A combined P-value test is described that is specifically designed to test the consensus of a set of independent tests, all of which address the same null hypothesis. It is shown that Fisher’s combined probability test is unsuitable in this application. A test based on the arithmetic mean of the normal-transformed P-value is shown to property balance component tests that support or refute a common null hypothesis. A means of determining the family-wide significance of individual tests, which are part of a collection of conceptually related tests, is also described.
Since the theoretical paper of Levin and Anderson1, it has been widely recognised that animal pollinators represent resources for which plants can compete. Competition for pollination might take several forms and act as a powerful selective force in establishing or maintaining sequential flowering among sympatric species2. Sequential flowering in Arctic3, temperate4–9 and neotropical10–13 plant assemblages has been interpreted as an evolutionary result of competition for pollination. This interpretation may prove correct in many cases, although strong evidence for competition is available for few systems9,14. Heinrich and Raven15 (see also Baker16 and Baker et al.
17) pointed out that sympatric plant species may act as mutualistic partners at the same time that their sequential flowering is maintained by competition. We develop this hypothesis here explicitly and present evidence that effective mutualism occurs between two species which also compete for pollination.
Milkweed (Asclepias syriaca L.: Asclepiadaceae) flowers exposed only to diurnal pollinators (primarily bumble bees, Bombus spp.) matured about eight times as many pods as did flowers exposed only to nocturnal visitors (moths). Rates of pollinaria removal and pollinia insertion were similarly higher during the day than at night. Moths deposited a much lower proportion of their pollinia in stigmatic chambers (one-fifth) than did diurnal pollinators. In spite of the poor service provided by nocturnal pollinators, flowers produced four times as much nectar at night as at day, and sugar production (sucrose equivalents) at night was twice that of the daytime.
Supplemental hand pollinations doubled the production of mature pods, indicating normal pollinia limitation. Mature pod production of clones within a 5-km diameter varied between 0.1 and 3.5 per flowering stem, and numbers of pollinia vectors at these clones were closely correlated with numbers of mature pods produced.
Pollinia-limited clones should thus attract both diurnal and nocturnal pollinators, if costs are not too extreme. Pollinia-limitation should decrease selection for pollinator specialization, especially if the relative importance of different pollinators varies over time, as in this study.
In a coastal region of Venezuela the daily energy expenditure (DEE) and water turnover of the flower visiting bat Anoura caudifer was measured by using the doubly labeled water method. In flower visitors, this method allows independent measurement of energy intake and expenditure if the animals drink no additional water and if the nectar's energy content is known. An average DEE of 12.4 kcal/d and water exchange of 13.4 ml/d were found. Our data show a balanced energy budget when animals in the field imbibe nectar with a sugar concentration of 18–21%, which is roughly medial in the range of nectar concentrations of various bat flowers. The energy turnover of flower visiting bats is high compared with DEEs of other bat species, small mammals and birds; flower visiting bats seem to belong to those species having a fast spin of the life motor.
Computer simulations of a pollinator foraging in a mixture of two species were used to explore how plant reproduction can be influenced by interspecific pollination movements. Interspecific pollen transfer led to strong competitive effects when availabilities of pollen, receptive stigma surfaces, or pollinator movements were limited relative to the total number of fertilizations possible in the mixed population. Results from simulations suggest that competition for pollination through interspecific pollen transfer can result in rapid exclusion of one of two species, and that such competition represents a selective force promoting stable divergence of potential competitors in habitat affinity, flowering time, or other characteristics related to pollinator sharing.
Pollination is one of the most important aspects of the life histories of most vascular plants. Until recently, there has been a broad consensus that heterospecific neighbors compete for pollinators, that this competition leads to phenological divergence, and that divergence leads to structured communities. New work is revealing a more complex web of interactions.
Thesis (Ph. D.)--Cornell University, 1974. Includes bibliographical references (leaves 138-146). Photocopy. s