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Here we investigate possible carryover effects of experimentally increased incubation temperatures for postnatal growth, metabolism, and parental care within and among 6 north temperate and one tropical songbird species. Increased temperatures during embryonic development consistently caused higher postnatal resting metabolism compared to control nests, among but not within the 7 species studied. The effects of the experiment on growth were species specific and depended on the morphometric considered. Size before the fledge date was positively correlated with feeding rate, and metabolism was lower in larger broods. Our experiment did not elicit changes in parental food delivery rates or brooding effort during the postnatal stage, and higher brooding effort was associated with nestlings of smaller mass and faster metabolism independently from treatment. Consequently, parental care seemed unlikely to be the cause of the differences in growth rates between treatments. Instead, physiological mechanisms triggered by our heating treatment appear to be responsible for the observed variation in growth. These intrinsic changes unmatched by adjustments in parental effort may contribute to longer-term consequences for individual quality and survival that deserve further attention.

 

The Skutch (1949) Hypothesis that nest predation risk constrains parental nest activity has important implications for the evolution of parental care strategies, but the required conditions for the hypothesis to operate have been questioned. We found the necessary conditions existed in a montane tropical bird community where 95.4% of predation events (n = 456) occurred during daylight hours and almost all predators (n = 224) were visually oriented. Moreover, incubation strategies for 21 passerine species were explained by nest predation rates as proposed by the Skutch Hypothesis. Hourly rates of visits to the nest were lower among species with higher nest predation rates, and achieved in part by longer on- and off-bouts. Incubation attentiveness (percent of time incubating) does not necessarily affect parental nest activity and was not related to nest predation rates. Nest predation rates were greater in enclosed- than open-nesting species, counter to long-standing views. Moreover, nest predation was usually higher in the nestling period when parents were more actively visiting nests than during incubation for enclosed- but not open-nesting species. This increase in nest predation in the nestling period for enclosed-nesting species might indicate proximate predation responses to parental nest activity that underlie the evolutionary patterns. Adult mortality also can exert selection on evolved strategies. Following life history theory, annual adult mortality probability explained residual variation in incubation behaviors, while accounting for nest predation, with longer-lived species exhibiting lower nest activity and attentiveness. Ultimately, the conditions for the Skutch Hypothesis were clear and evolved behaviors suggest an important influence of natural selection by nest predation in this montane tropical bird community. At the same time, different patterns of nest predation between open- and enclosed-nesting species emphasize a need for further research into how parental nest activity interacts with nest type to affect predator detection of nests.

 

Understanding and describing the diversity of living organisms is a great challenge. Fungi have for a long time been, and unfortunately still are, underestimated when it comes to taxonomic research. The foundations were laid by the first mycologists through field observations. These important fundamental works have been and remain vital reference works. Nevertheless, a non-negligible part of the studied funga escaped their attention. Thanks to modern developments in molecular techniques, the study of fungal diversity has been revolutionized in terms of tools and knowledge. Despite a number of disadvantages inherent to these techniques, traditional field-based inventory work has been increasingly superseded and neglected. This perspective aims to demonstrate the central importance of field-based research in fungal diversity studies, and encourages researchers not to be blinded by the sole use of molecular methods. 

Neotropical cloud forests are biologically and ecologically unique and represent a largely untapped reservoir of species new to science, particularly for understudied groups like those within the Kingdom Fungi. We conducted a three-week fungal survey within Cusuco National Park, Honduras and made 116 collections of fungi in forest habitats at 1287–2050 m a.s.l. Undescribed species are likely to be present in those collections, including members of the genera Calostoma (Boletales), Chlorociboria, Chlorosplenium, Ionomidotis (Helotiales), Amparoina, Cyathus, Gymnopus, Pterula (Agaricales), Lactifluus (Russulales), Mycocitrus (Hypocreales), Trechispora (Trechisporales), and Xylaria (Xylariales). In this paper, we discuss the contributions and impacts of mycological surveys in the Neotropics and propose the establishment of a long-term mycological inventory at Cusuco National Park—the first of its kind in northern Central America. 

Most empirical research on biological shortfalls has focused on vertebrate taxa. This is important given many species in poorly studied groups such as invertebrates, plants, and fungi are predicted to possess high conservation risk. Here, we focus on Laboulbeniomycetes: a class of microfungi that are understudied. We examined four shortfalls: Linnean (knowledge gaps in species diversity), Wallacean (knowledge gaps in distributions), Latimerian (knowledge gaps in species persistence), and the newly introduced Scottian (knowledge gaps in species conservation assessments) shortfalls. The Linnean shortfall in Laboulbeniomycetes is hard to predict due to inconsistent species description rates. Analysis of distribution patterns indicates Laboulbeniomycetes are likely to experience an extremely high Wallacean shortfall, with many species having highly disjunct known distributions. Latimerian shortfall analysis shows over half (51%) of Laboulbeniomycetes have not been recorded in >50 years, while the group has a collective Scottian shortfall of 100%, given none of the 2454 described species have received an IUCN threat assessment. We suggest continued study of natural history collections, expanded citizen science programmes, and machine‐learning identification approaches as important tools for reducing knowledge shortfalls in both Laboulbeniomycetes and poorly studied taxa more generally.

 

ABSTRACT Metabolism is thought to mediate the connection between environmental selection pressures and a broad array of life history tradeoffs, but tests are needed. High juvenile predation correlates with fast growth, which may be achieved via fast juvenile metabolism. Fast offspring metabolism and growth can create physiological costs later in life that should be minimized in species with low adult mortality. Yet, relationships between juvenile metabolism and mortality at offspring versus adult stages are unexplored. We found that post-natal metabolism was positively correlated with adult mortality but not nest predation rates among 43 songbird species on three continents. Nest predation, but not adult mortality, explained additional variation in growth rates beyond metabolism. Our results suggest that metabolism may not be the mechanism underlying the relationships between growth and mortality at different life stages.