A Lost Link between a Flightless Parrot and a Parasitic Plant and the Potential Role of Coprolites in Conservation Paleobiology.
- Conservation biology : the journal of the Society for Conservation Biology
- Published over 7 years ago
Late Quaternary extinctions and population fragmentations have severely disrupted animal-plant interactions globally. Detection of disrupted interactions often relies on anachronistic plant characteristics, such as spines in the absence of large herbivores or large fruit without dispersers. However, obvious anachronisms are relatively uncommon, and it can be difficult to prove a direct link between the anachronism and a particular faunal taxon. Analysis of coprolites (fossil feces) provides a novel way of exposing lost interactions between animals (depositors) and consumed organisms. We analyzed ancient DNA to show that a coprolite from the South Island of New Zealand was deposited by the rare and threatened kakapo (Strigops habroptilus), a large, nocturnal, flightless parrot. When we analyzed the pollen and spore content of the coprolite, we found pollen from the cryptic root-parasite Dactylanthus taylorii. The relatively high abundance (8.9% of total pollen and spores) of this zoophilous pollen type in the coprolite supports the hypothesis of a former direct feeding interaction between kakapo and D. taylorii. The ranges of both species have contracted substantially since human settlement, and their present distributions no longer overlap. Currently, the lesser short-tailed bat (Mystacina tuberculata) is the only known native pollinator of D. taylorii, but our finding raises the possibility that birds, and other small fauna, could have once fed on and pollinated the plant. If confirmed, through experimental work and observations, this finding may inform conservation of the plant. For example, it may be possible to translocate D. taylorii to predator-free offshore islands that lack bats but have thriving populations of endemic nectar-feeding birds. The study of coprolites of rare or extinct taxonomic groups provides a unique way forward to expand existing knowledge of lost plant and animal interactions and to identify pollination and dispersal syndromes. This approach of linking paleobiology with neoecology offers significant untapped potential to help inform conservation and restoration plans. Un Eslabón Perdido entre un Loro No Volador y una Planta Parásita y el Papel Potencial de Coprolitos en Paleobiología de la Conservación.
Because of recent interest in bats as reservoirs of emerging diseases, we investigated the presence of viruses in Mystacina tuberculata bats in New Zealand. A novel alphacoronavirus sequence was detected in guano from roosts of M. tuberculata bats in pristine indigenous forest on a remote offshore island (Codfish Island).
This article presents a characterization of cortical responses to artificial and natural temporally-patterned sounds in the bat species Carollia perspicillata, a species that produces vocalizations at rates above 50 Hz. Multi-unit activity was recorded in three different experiments. In the first experiment, amplitude modulated (AM) pure tones were used as stimuli to drive auditory cortex (AC) units. AC units of both ketamine-anesthetized and awake bats could lock their spikes to every cycle of the stimulus modulation envelope, but only if the modulation frequency was below 22 Hz. In the second experiment, two identical communication syllables were presented at variable intervals. Suppressed responses to the lagging syllable were observed, unless the second syllable followed the first one with a delay of at least 80 ms (i.e. 12.5 Hz repetition rate). In the third experiment, natural distress vocalization sequences were used as stimuli to drive AC units. Distress sequences produced by C. perspicillata contain bouts of syllables repeated at intervals of ~60 ms (16 Hz). Within each bout, syllables are repeated at intervals as short as 14 ms (~ 71 Hz). Cortical units could follow the slow temporal modulation flow produced by the occurrence of multisyllabic bouts, but not the fast acoustic-flow created by rapid syllable repetition within the bouts. Taken together, our results indicate that even in fast vocalizing animals, such as bats, cortical neurons can only track the temporal structure of acoustic streams modulated at frequencies lower than 22 Hz. This article is protected by copyright. All rights reserved.
Seasonal changes in weather and food availability differentially impact energy budgets of small mammals such as bats. While most thermal physiological research has focused on species that experience extreme seasonal temperature variations, knowledge is lacking from less variable temperate to subtropical climates. We quantified ambient temperature (T a) and skin temperature (T sk) responses by individuals from a population of New Zealand lesser short-tailed bats (Mystacina tuberculata) during summer and winter using temperature telemetry. During summer, communal roosts were more thermally stable than T a. During winter, solitary roosts were warmer than T a indicating significant thermal buffering. Communal roost trees were used on 83 % of observation days during summer, and individuals occupying them rarely entered torpor. Solitary roosts were occupied on 93 % of observation days during winter, and 100 % of individuals occupying them used torpor. During summer and winter, bats employed torpor on 11 and 95 % of observation days, respectively. Maximum torpor bout duration was 120.8 h and winter torpor bout duration correlated negatively with mean T a. Torpor bout duration did not differ between sexes, although female minimum T sk was significantly lower than males. The summer Heterothermy Index varied, and was also significantly affected by T a. Mean arousal time was correlated with sunset time and arousals occurred most frequently on significantly warmer evenings, which are likely associated with an increased probability of foraging success. We provide the first evidence that torpor is used flexibly throughout the year by M. tuberculata, demonstrating that roost choice and season impact torpor patterns. Our results add to the growing knowledge that even small changes in seasonal climate can have large effects on the energy balance of small mammals.
The use of alternative reproductive tactics is widespread in animals. Males of some species may change tactics depending on age, body condition and social environment. Many bat species are polygynous where a fraction of males only have access to fertile females. For polygynous bats, knowledge of the reproductive success of males using different alternative reproductive tactics is scarce, and it remains unclear how age of males is related to switching decisions between social statuses. We studied a large captive population of Carollia perspicillata, where males are either harem holders, bachelors or peripheral males. Using a multistate procedure, we modeled the age-related switches in reproductive tactics and in survival probability. From the model, we calculated the reproductive success and the frequencies of males displaying different reproductive tactics. Since in mammals the switch between social statuses is often related to age, we predicted that the transition probability of bachelor and peripheral males to harem status would increase with age. We show, however, that social status transition towards a harem holding position was not related to age. Reproductive success changed with age and social status. Harem males had a significantly higher reproductive success than bachelor males except between a short period from 3.8 to 4.4 years of age where success was similar, and a significantly higher reproductive success than peripheral males between 2.6 and 4.4 years of age. Harem males showed a clear decrease in the probability of maintaining social status with age, which suggests that senescence reduces resource holding potential. This article is protected by copyright. All rights reserved.
- Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology
- Published almost 4 years ago
A number of studies have successfully used electrocardiogram (ECG) signals to characterize complex physiological phenomena such as associative learning in bats. However, at present, no thorough characterization of the structure of ECG signals is available for these animals. The aim of the present study was to quantitatively characterize features of the ECG signals in the bat species Carollia perspicillata, a species that is commonly used in neuroethology studies. Our results show that the ECG signals of C. perspicillata follow the typical mammalian pattern, in that they are composed by a P wave, QRS complex and a T wave. Peak-to-peak amplitudes in the bats' ECG signals were larger in measuring configurations in which one of the electrodes was attached to the right thumb. In addition, large differences in the instantaneous heart rate (HR) distributions were observed between ketamine/xylazine anesthetized and awake bats. Ketamine/xylazine might target the neural circuits that control HR, therefore, instantaneous HR measurements should only be used as physiological marker in awake animals.
Bats harbour a diverse array of viruses, including significant human pathogens. The extensive metagenomic study of material from bats, in particular guano, has revealed a large number of novel or divergent viral taxa that were previously unknown. New Zealand has only two extant indigenous terrestrial mammals which are both bats, Mystacina tuberculata (lesser short-tailed bat) and Chalinobus tuberculatus (long-tailed bat). Until the human introduction of exotic mammals, these species had been isolated from all other terrestrial mammals for over one million years (potentially over 16 million years for M. tuberculata). Four bat guano samples were collected from M. tuberculata roosts on the isolated offshore island of Whenua hou (Codfish Island). Metagenomic analysis reveals that this species still hosts a plethora of divergent viruses. While the majority of viruses detected were likely to be of dietary origin, some putative vertebrate virus sequences were identified. Papillomavirus, polyomavirus, calicivirus and hepevirus were found in the metagenomic data and then subsequently confirmed using independent PCR assays and sequencing. The new hepevirus and calicivirus sequences may represent new genera within these viral families. Our findings may provide an insight into the origins of viral families given their detection in an isolated host species.
Abstract Primary and secondary poisoning of nontarget wildlife with second-generation anticoagulant rodenticides has led to restrictions on their use and to increased use of first-generation anticoagulants, including diphacinone. Although first-generation anticoagulants are less potent and less persistent than second-generation compounds, their use is not without risks to nontarget species. We report the first known mortalities of threatened New Zealand lesser short-tailed bats (Mystacina tuberculata) caused by diphacinone intoxication. The mortalities occurred during a rodent control operation in Pureora Forest Park, New Zealand, during the 2008-2009 Austral summer. We observed 115 lesser short-tailed bat deaths between 9 January and 6 February 2009, and it is likely that many deaths were undetected. At necropsy, adult bats showed gross and histologic hemorrhages consistent with coagulopathy, and diphacinone residues were confirmed in 10 of 12 liver samples tested. The cause of mortality of pups was diagnosed as a combination of the effects of diphacinone toxicity, exposure, and starvation. Diphacinone was also detected in two of 11 milk samples extracted from the stomachs of dead pups. Eight adults and 20 pups were moribund when found. Two adults and five pups survived to admission to a veterinary hospital. Three pups responded to treatment and were released at the roost site on 17 March, 2009. The route of diphacinone ingestion by adult bats is uncertain. Direct consumption of toxic bait or consumption of poisoned arthropod prey could have occurred. We suggest that the omnivorous diet and terrestrial feeding habits of lesser short-tailed bats make them susceptible to poisoning with the bait matrix and the method of bait delivery used. We recommend the use of alternative vertebrate pesticides, bait matrices, and delivery methods in bat habitat.