Individual variability in diving behavior of the Black-vented Shearwater in an ever-changing habitat.

Oceanic mesoscale systems are characterized by inherent variability. Climatic change adds entropy to this system, making it a highly variable environment in which marine species live. Being at the higher levels of the food chain, predators maximize their performance through plastic foraging strategies. Individual variability within a population and the possible repeatability across time and space may provide stability in a population facing environmental changes. Therefore, variability and repeatability of behaviors, particularly diving behavior, could play an important role in understanding the adaptation pathway of a species. This study focuses on characterizing the frequency and timing of different dives (termed simple and complex) and how these are influenced by individual and environmental characteristics (sea surface temperature, chlorophyll a concentration, bathymetry, salinity, and Ekman transport). This study is based on GPS and accelerometer-recorded information from a breeding group of 59 Black-vented Shearwater and examine consistency in diving behavior at both individual and sex levels across four different breeding seasons. The species was found to be the best performing free diver in the Puffinus genus with a maximum dive duration of 88 s. Among the environmental variables assessed, a relationship was found with active upwelling conditions enhancing low energetic cost diving, on the contrary, reduced upwelling and warmer superficial waters induce more energetically demanding diving affecting diving performance and ultimately body conditions. The body conditions of Black-vented Shearwaters in 2016 were worse than in subsequent years, in 2016, deepest and longest complex dives were recorded, while simple dives were longer in 2017-2019. Nevertheless, the species' plasticity allows at least part of the population to breed and feed during warmer events. While carry-over effects have already been reported, the effect of more frequent warm events is still unknown.

Araneophagy as an alternative foraging tactic to kleptoparasitism in two Argyrodinae (Araneae: Theridiidae) species.

Kleptoparasitism is assumed to be the main foraging strategy in some animal groups, such as the spiders of the subfamily Argyrodinae (Theridiidae). However, some species may also feed on silk threads, egg sacs, or even their hosts. The conditions determining these alternative foraging tactics remain unknown for most species. We performed field observations, stable isotope analysis and laboratory experiments to investigate kleptoparasitism and araneophagy of Argyrodes elevatus and Faiditus caudatus in webs of Manogea porracea (Araneidae). We evaluated the following hypotheses: (1) both species exhibit higher trophic positions than their hosts and closest to an araneophagic sympatric species; (2) host web selection is influenced by the presence of alternative resources (adult male and female, and egg sacs); and (3) they preferentially consume egg sacs instead of stored prey items. Both argyrodines showed higher trophic positions than their female hosts and closest to an araneophagic spider species. The invaders were found mainly on host webs with one adult and egg sacs and with egg sacs only. Finally, A. elevatus preferred to feed on prey captured by the host spider instead of egg sacs. We discussed the factors that can potentially determine the choices between foraging exclusively as kleptoparasites and consuming the hosts.

Metabolic hormones, grazing behaviour, offspring physical distance and productive response of beef cow grazing at two herbage allowances.

Herbage allowance (HA) management during gestation-lactation cycle of cows grazing native grasslands improves pregnancy rates and calves' weaning weight records. Those improvements were associated with greater herbage mass, and better body condition score (BCS) and metabolic status of the cows, which could affect grazing and maternal behaviour, particularly when temporary suckling restriction (TSR) and flushing (FL) is applied. The objective of this study was to evaluate the effect of HA during the gestation-lactation period on cows' and calves' liveweight (LW), BCS, milk yield, insulin, IGF-1 and leptin concentrations, as well as the proportion of diurnal grazing activities (grazing, ruminating, walking and idling), and maternal behaviour from -10 to 70 days relative to TSR (day 0 = initiation of TSR at 86 ± 10 days relative to calving). Thirty-three primiparous Hereford cows were allocated to HA treatments during gestation and lactation, which annually averaged 2.5 (low = LHA) and 4 kg DM/kg LW (high = HHA). The LW and BCS of cows did not differ during -10 to 50 days but were greater in HHA than LHA at the end of the study (P < 0.05). Concentrations of IGF-1 were greater in HHA compared to LHA, while insulin and leptin did not differ. Grazing was lower in HHA than LHA, and the opposite occurred with ruminating and idling (P < 0.05). Cow-calf physical distance was greater in LHA cows compared to HHA (P < 0.05) and increased greatly in the former group after FL, while this increase was lower and later in HHA cows. Milk yield was greater in HHA (P < 0.05), and calves' weight did not differ between treatments from day -10 to 35, but was greater in HHA compared to LHA from 45 days until the end of the study. Thus, the HHA in a low herbage height and mass condition resulted in greater IGF-1 concentrations and milk yield, and induced changes in grazing and maternal behaviour that were associated with increased cows' LW, BCS and calves' weight at the end of the study.

Spider community responds to litter complexity: insights from a small-scale experiment in an exotic pine stand / Comunidade de aranhas responde a complexidade da serapilheira: percepções de um experimento de pequena escala em um talhão de pinus exótico

Conservation of biodiversity in agroecosystems is an urgent need, and a suitable approach to maximize animal biodiversity and their services is the restoration of habitat heterogeneity. Here we investigated the value of increasing litter complexity in tree plantations of exotic pine for ground spiders. We hypothesized that increasing the litter complexity of these systems, as it would be the case in ecologically designed plantations, would increase spider aggregations. We performed a small-scale litter manipulation experiment within an exotic pine stand in the municipality of Minas do Leão, Rio Grande do Sul, Brazil, and compared spider diversity in simple (only pine needles) and complex substrates (with the addition of diverse native broadleaves). We found 1,110 spiders, 19 families and 32 morphospecies. The most abundant families were Linyphiidae, Theridiidae and Salticidade, and the dominant morphospecies were Thymoites sp. 2 and Lygarina sp. Web-building spiders represented 61% of total spider abundance, and 17 species, while hunting spiders, 49% and 15 species. As expected, densities of spider individuals and species from both web-building and hunting spiders were higher in complex litter substrate. Potential preys (Collembola) also responded positively to the treatment, and had influence of spider community patterns. Our results suggest that ensuring some degree of plant and litter diversity within pine stands (e.g. understory establishment) might foster spider aggregations and possibly help to conserve their diversity at local-scales.

A conservação da biodiversidade em agroecossistemas é uma necessidade urgente, e uma abordagem adequada a maximizar a biodiversidade animal e seus serviços é a restauração da heterogeneidade de habitats. Aqui nós investigamos o valor do aumento da complexidade da serapilheira em plantações exóticas de pinus para aranhas de solo. Nossa hipótese é que aumentando a complexidade da serapilheira nestes sistemas, como seria o caso em plantações com design ecológico, as agregações de aranhas aumentariam. Nós realizamos uma manipulação experimental de pequena escala em uma plantação exótica de pinus no município de Minas do Leão, Rio Grande do Sul, e comparamos a diversidade de aranhas em substrato simples (somente acículas de pinus) e complexo (com adição de folhas nativas diversas). Nós encontramos 1.110 aranhas, 19 famílias e 32 morfoespécies. As famílias mais abundantes foram Linyphiidae, Theridiidae e Salticidade, e as morfoespécies dominantes foram Thymoites sp. 2 e Lygarina sp. Aranhas de teia representaram 61% da abundância total de aranhas e 17 espécies, enquanto aranhas caçadoras, 49% e 15 espécies. Como esperado, densidades de indivíduos e de espécies de ambas construtoras de teia e caçadoras foram maiores em substrato complexo. Potenciais presas (Collembola) também responderam positivamente ao tratamento, e influenciaram os padrões das comunidades de aranhas. Nossos resultados sugerem que garantir algum grau de diversidade de plantas e serapilheira dentro de talhões de pinus (e.g. estabelecimento de sub-bosque) poderia promover agregações de aranhas e possivelmente ajudar a conservar sua diversidade em escalas locais.

Spider community responds to litter complexity: insights from a small-scale experiment in an exotic pine stand

ABSTRACT Conservation of biodiversity in agroecosystems is an urgent need, and a suitable approach to maximize animal biodiversity and their services is the restoration of habitat heterogeneity. Here we investigated the value of increasing litter complexity in tree plantations of exotic pine for ground spiders. We hypothesized that increasing the litter complexity of these systems, as it would be the case in ecologically designed plantations, would increase spider aggregations. We performed a small-scale litter manipulation experiment within an exotic pine stand in the municipality of Minas do Leão, Rio Grande do Sul, Brazil, and compared spider diversity in simple (only pine needles) and complex substrates (with the addition of diverse native broadleaves). We found 1,110 spiders, 19 families and 32 morphospecies. The most abundant families were Linyphiidae, Theridiidae and Salticidade, and the dominant morphospecies were Thymoites sp. 2 and Lygarina sp. Web-building spiders represented 61% of total spider abundance, and 17 species, while hunting spiders, 49% and 15 species. As expected, densities of spider individuals and species from both web-building and hunting spiders were higher in complex litter substrate. Potential preys (Collembola) also responded positively to the treatment, and had influence of spider community patterns. Our results suggest that ensuring some degree of plant and litter diversity within pine stands (e.g. understory establishment) might foster spider aggregations and possibly help to conserve their diversity at local-scales.

RESUMO A conservação da biodiversidade em agroecossistemas é uma necessidade urgente, e uma abordagem adequada a maximizar a biodiversidade animal e seus serviços é a restauração da heterogeneidade de habitats. Aqui nós investigamos o valor do aumento da complexidade da serapilheira em plantações exóticas de pinus para aranhas de solo. Nossa hipótese é que aumentando a complexidade da serapilheira nestes sistemas, como seria o caso em plantações com design ecológico, as agregações de aranhas aumentariam. Nós realizamos uma manipulação experimental de pequena escala em uma plantação exótica de pinus no município de Minas do Leão, Rio Grande do Sul, e comparamos a diversidade de aranhas em substrato simples (somente acículas de pinus) e complexo (com adição de folhas nativas diversas). Nós encontramos 1.110 aranhas, 19 famílias e 32 morfoespécies. As famílias mais abundantes foram Linyphiidae, Theridiidae e Salticidade, e as morfoespécies dominantes foram Thymoites sp. 2 e Lygarina sp. Aranhas de teia representaram 61% da abundância total de aranhas e 17 espécies, enquanto aranhas caçadoras, 49% e 15 espécies. Como esperado, densidades de indivíduos e de espécies de ambas construtoras de teia e caçadoras foram maiores em substrato complexo. Potenciais presas (Collembola) também responderam positivamente ao tratamento, e influenciaram os padrões das comunidades de aranhas. Nossos resultados sugerem que garantir algum grau de diversidade de plantas e serapilheira dentro de talhões de pinus (e.g. estabelecimento de sub-bosque) poderia promover agregações de aranhas e possivelmente ajudar a conservar sua diversidade em escalas locais.

Spider community responds to litter complexity: insights from a small-scale experiment in an exotic pine stand / Comunidade de aranhas responde a complexidade da serapilheira: percepções de um experimento de pequena escala em um talhão de pinus exótico

Conservation of biodiversity in agroecosystems is an urgent need, and a suitable approach to maximize animal biodiversity and their services is the restoration of habitat heterogeneity. Here we investigated the value of increasing litter complexity in tree plantations of exotic pine for ground spiders. We hypothesized that increasing the litter complexity of these systems, as it would be the case in ecologically designed plantations, would increase spider aggregations. We performed a small-scale litter manipulation experiment within an exotic pine stand in the municipality of Minas do Leão, Rio Grande do Sul, Brazil, and compared spider diversity in simple (only pine needles) and complex substrates (with the addition of diverse native broadleaves). We found 1,110 spiders, 19 families and 32 morphospecies. The most abundant families were Linyphiidae, Theridiidae and Salticidade, and the dominant morphospecies were Thymoites sp. 2 and Lygarina sp. Web-building spiders represented 61% of total spider abundance, and 17 species, while hunting spiders, 49% and 15 species. As expected, densities of spider individuals and species from both web-building and hunting spiders were higher in complex litter substrate. Potential preys (Collembola) also responded positively to the treatment, and had influence of spider community patterns. Our results suggest that ensuring some degree of plant and litter diversity within pine stands (e.g. understory establishment) might foster spider aggregations and possibly help to conserve their diversity at local-scales.(AU)

A conservação da biodiversidade em agroecossistemas é uma necessidade urgente, e uma abordagem adequada a maximizar a biodiversidade animal e seus serviços é a restauração da heterogeneidade de habitats. Aqui nós investigamos o valor do aumento da complexidade da serapilheira em plantações exóticas de pinus para aranhas de solo. Nossa hipótese é que aumentando a complexidade da serapilheira nestes sistemas, como seria o caso em plantações com design ecológico, as agregações de aranhas aumentariam. Nós realizamos uma manipulação experimental de pequena escala em uma plantação exótica de pinus no município de Minas do Leão, Rio Grande do Sul, e comparamos a diversidade de aranhas em substrato simples (somente acículas de pinus) e complexo (com adição de folhas nativas diversas). Nós encontramos 1.110 aranhas, 19 famílias e 32 morfoespécies. As famílias mais abundantes foram Linyphiidae, Theridiidae e Salticidade, e as morfoespécies dominantes foram Thymoites sp. 2 e Lygarina sp. Aranhas de teia representaram 61% da abundância total de aranhas e 17 espécies, enquanto aranhas caçadoras, 49% e 15 espécies. Como esperado, densidades de indivíduos e de espécies de ambas construtoras de teia e caçadoras foram maiores em substrato complexo. Potenciais presas (Collembola) também responderam positivamente ao tratamento, e influenciaram os padrões das comunidades de aranhas. Nossos resultados sugerem que garantir algum grau de diversidade de plantas e serapilheira dentro de talhões de pinus (e.g. estabelecimento de sub-bosque) poderia promover agregações de aranhas e possivelmente ajudar a conservar sua diversidade em escalas locais.(AU)

FORRAJEO DE Zonotrichia capensis (Passeriformes: Emberizidae) Y VALOR DEL PARCHE EN CERCAS VIVAS JÓVENES DE LA SABANA DE BOGOTÁ / Foraging Behavior of Zonotrichia capensis (Passeriformes: Emberizidae) and Patch Value in Young Live Fences in the Bogotá High Plateau

El copetón Zonotrichia capensis tiene una amplia distribución en América neotropical, es un ave tolerante a las intervenciones humanas, pero sabemos poco sobre su comportamiento de forrajeo en los Andes colombianos. Por ello, estudiamos la estrategia de forrajeo del copetón y, adicionalmente, el valor de parches alimentarios a lo largo de dos cercas vivas jóvenes (plantación < 2 años), en relación con la distancia a una zona de ronda del río Bogotá, en Cajicá, Sabana de Bogotá, Colombia. El río es un área dominada por árboles en una matriz rural a urbana. Utilizamos parches artificiales hechos de bandejas de aluminio con semillas mezcladas con arena. Determinamos la proporción de consumo entre tres parches con diferentes densidades de alimento inicial, para determinar si los copetones obtienen información del parche. Usamos también parches artificiales para determinar si la distancia al río a lo largo de dos cercas vivas jóvenes afectaba el forrajeo. Nuestros resultados indican que Z. capensis no obtuvo información del parche y no reconoció diferencias en parches con diferente densidad inicial de alimento. Adicionalmente, la distancia al río afectó el valor de los parches de forrajeo en solo una de las cercas vivas examinadas donde hubo mayor consumo cerca al río. Al parecer, la densidad inicial de alimento no afectó el nivel de explotación del parche por parte de los copetones, mientras que el valor del parche en las cercas vivas jóvenes puede estar influido por la distancia al río.

The Rufous-collared Sparrow Zonotrichia capensis is a widely distributed species in neotropical America, it is tolerant to human interventions, but we know little about its foraging ecology on the Colombian Andes. Therefore, we studied the foraging strategy and, additionally, the value of foraging patches along two young live fences (< 2 year planted) in relation to the Bogota River in Cajica, in an Andean highland plateau in Colombia. The Bogota River is one of few areas dominated by arboreal vegetation in an urban-rural matrix at the study site. We used artificial food patches made of aluminum trays with seeds mixed with sand. We measured the proportion of food consumed in patches with different initial food density to determine whether sparrows obtain information from the patch. We also used artificial patches to determine whether distance to the river affected the sparrow's foraging in two young live fences. Our results indicate that Z. capensis did not gather any information from the patch and did not differentiate patches with different amounts of food. Furthermore, the distance to the river affected the value of food patches, but only in one of the live fences, where there was higher food consumption close to the river. Apparently, the food initial-density did not affect the patch exploitation level by sparrows, but the patch value in young live fences could be influenced by distance to the river.

Foraging of Great Kiskadees (Pitangus sulphuratus) and food items offered to nestlings in the Pantanal / Forrageamento de bem-te-vis (Pitangus sulphuratus) e itens alimentares oferecidos para ninhêgos no Pantanal

Feeding of Pitangus sulphuratus (Tyrannidae) nestlings have been poorly studied. Here we describe the foraging behavior of a P. sulphuratus pair and the searching and offering time of food items to nestlings in the Pantanal, Brazil. Data collection was carried out over 25 days on the outskirts of the Base de Estudos do Pantanal building, inhabited by insectivorous bats. Records were based on direct observations with the help of binocular. The pair required little time for searching for small insects and fruits, but these items comprised a little amount of food per event of capture. Some large prey was more time-costly for searching, but the long period that these food items were offered to nestlings overcompensated the searching time. Considering the time of feeding nestlings (benefit) in relation to the searching time by the parents (cost), bats and snails are the most advantageous items for P. sulphuratus parents feeding nestlings at the study site.

A alimentação de ninhêgos de Pitangus sulphuratus (Tyrannidae) tem sido pouco estudada. Descrevemos, neste estudo, o comportamento de forrageamento de um casal de P. sulphuratus e o tempo para busca e oferta de itens aos ninhêgos, no Pantanal, Brasil. A coleta de dados foi realizada durante 25 dias nas proximidades do prédio da Base de Estudos do Pantanal, habitada por morcegos insetívoros. Os registros foram baseados em observações diretas com auxílio de binóculo. O casal demandou pouco tempo de busca para a captura de pequenos insetos e frutos, porém esses itens representaram pouca quantidade de alimento por evento de captura. Algumas presas grandes demandaram mais tempo para busca, mas o longo período que esses itens foram oferecidos aos ninhêgos sobrecompensou o tempo de busca. Considerando-se o tempo de alimentação dos ninhêgos (benefício) em relação ao tempo de busca pelos pais (custo), morcegos e caramujos são itens mais vantajosos para os pais de P. sulphuratus alimentar ninhêgos no local de estudo.

Foraging of Great Kiskadees (Pitangus sulphuratus) and food items offered to nestlings in the Pantanal

Feeding of Pitangus sulphuratus (Tyrannidae) nestlings have been poorly studied. Here we describe the foraging behavior of a P. sulphuratus pair and the searching and offering time of food items to nestlings in the Pantanal, Brazil. Data collection was carried out over 25 days on the outskirts of the Base de Estudos do Pantanal building, inhabited by insectivorous bats. Records were based on direct observations with the help of binocular. The pair required little time for searching for small insects and fruits, but these items comprised a little amount of food per event of capture. Some large prey was more time-costly for searching, but the long period that these food items were offered to nestlings overcompensated the searching time. Considering the time of feeding nestlings (benefit) in relation to the searching time by the parents (cost), bats and snails are the most advantageous items for P. sulphuratus parents feeding nestlings at the study site.

A alimentação de ninhêgos de Pitangus sulphuratus (Tyrannidae) tem sido pouco estudada. Descrevemos, neste estudo, o comportamento de forrageamento de um casal de P. sulphuratus e o tempo para busca e oferta de itens aos ninhêgos, no Pantanal, Brasil. A coleta de dados foi realizada durante 25 dias nas proximidades do prédio da Base de Estudos do Pantanal, habitada por morcegos insetívoros. Os registros foram baseados em observações diretas com auxílio de binóculo. O casal demandou pouco tempo de busca para a captura de pequenos insetos e frutos, porém esses itens representaram pouca quantidade de alimento por evento de captura. Algumas presas grandes demandaram mais tempo para busca, mas o longo período que esses itens foram oferecidos aos ninhêgos sobrecompensou o tempo de busca. Considerando-se o tempo de alimentação dos ninhêgos (benefício) em relação ao tempo de busca pelos pais (custo), morcegos e caramujos são itens mais vantajosos para os pais de P. sulphuratus alimentar ninhêgos no local de estudo.

Polinizadores de Bertholletia excelsa (Lecythidales: Lecythidaceae): interações com abelhas sem ferrão (Apidae: Meliponini) e nicho trófico / Pollinators of Bertholletia excelsa (Lecythidales: Lecythidaceae): interactions with stingless bees (Apidae: Meliponini) and trophic niche

This paper presents an analysis of the foraging behavior and interactions of Xylocopa frontalis Olivier (Apidae: Xylocopini) and Eulaema mocsaryi (Friese) (Apidae: Euglossini) in the presence of stingless bees (Apidae: Meliponini) in flowers of Bertholletia excelsa, the Brazilian nut. The palynological load carried by both species was also examined. This study was conducted in the farm Aruanã, Itacoatiara/ Amazonas state, Brazil, during the flowering peak of B. excelsa. The visitation by the main pollinators X. frontalis and E. mocsaryi were influenced by the presence and activities of stingless bees in the flowers of B. excelsa. Meliponini bees did not have any effect on the visits and collection of floral resources by X. frontalis, while negatively affecting the number of visits by E. mocsaryi. The stingless bees presented a variety of strategies to get access to pollen grains of B. excelsa, grouped into two categories: opportunism -Frieseomelitta trichocerata Moure, Tetragona goettei (Friese), and Tetragona kaieteurensis (Schwarz), and stealing -Trigona branneri Cockerell, Trigona fuscipennis Friese, and Trigona guianae Cockerell. The palynological analysis from X. frontalis showed that the bee collected pollen in a few species of plants, but mainly on B. excelsa. The pollen grains of B. excelsa were poorly represented in the pollen shipments of E. mocsaryi, due to its large trophic niche in the locality.