Funambulus palmarum: The danger of roadkill deaths to Three-striped Palm Squirrels on the Sigur Plateau, Tamil Nadu.

The Three-striped Palm Squirrel, Funambulus palmarum, is a small Rodent of the Sciuridae family, with four subspecies native to India and Sri Lanka. Funambulus palmarum is endemic to southern India and Sri Lanka, where it is widely distributed from sea level to 2000 m. Squirrels can reach head-body length of 12–15 cm and tail length of 14–15 cm, and they have short fur that is yellowish-brown or brown on the back and creamy white on the belly. Three white stripes on the back stretch from the head to tail. Funambulus palmarum has dark round eyes, small triangular ears, long front teeth, and a bushy tail. It is an omnivore with a diet based largely on fruit and nuts that also includes eggs, small Birds, larvae, and Insects. Squirrels mate throughout the year and build nests in treetops using grass and branches. Pregnancy lasts 34 to 45 days and produces 1–5 offspring; young are fully weaned at 10 weeks and reach sexual maturity at nine months. Animals can survive up to four years in the wild and over 5 years in captivity. 

 

A Three-striped Palm Squirrel, Funambulus palmarum. Yathin Krishnappa/Wikimedia Commons.

In a paper published in the Journal of Threatened Taxa on 26 July 2020, Arockianathan Samson of the Vulture Programme of the Bombay Natural History Society, Balasundaram Ramakrishnan of Mammalogy and Forest Ecology, and Jabamalainathan Leonaprincy at the Herpetology and Tribal Medicine Lab of the departments of Zoology and Wildlife Biology at the Government Arts College, Udhgamandalam, present the results of a study which was undertaken to assess the threat to Three-striped Palm Squirrels from roadkills in the tropical forest of Sigur Plateau, Tamil Nadu in southern India.

Sigur Plateau is located in Mudumalai Tiger Reserve. It is a connective junction of Western and Eastern Ghats and harbors a diverse range of wildlife that includes Asian Elephant, Elephas maximus, Tiger, Panthera tigris, Leopard, Panthera pardus, Gaur, Bos gaurus, Chital, Axis axis, Sambar, Rusa unicolor, and other Mammals, as well as Birds such as Endangered and Critically Endangered Vultures including the Long-billed Vulture, Gyps indicus, Whiterumped Vulture, Gyps bengalensis, Red-headed Vulture, Sacrogyps calvus, and Egyptian Vulture, Neophran percnopterus. The corridor between the Western and Eastern Ghats is used by Elephants, Tiger, Gaur, and other herbivores for seasonal migrations influenced by the southwest and northeast monsoons. The major streams of Sigur Plateau are the Moyar River, the Sigur River, the Avarahalla River, the Kedarhalla River, and the Gundattihalla River, which crisscross the Moyar Valley and drain into the Bhavanisagar Reservoir. Villages located within the Sigur Plateau are home to local communities and more recently to several tourist facilities that subsist mainly on the attractions of the diverse wildlife in the area surrounding Mudumalai Tiger Reserve.

Roadkills were recorded along the Udhagamandalam–Masinagudi state highway passing through Mudumalai Tiger Reserve (40km). The local habitats are classified as dry thorn forest and dry deciduous forest. Four visits per month were carried out between January 2014 and December 2016, mostly on weekends (Saturday or Sunday) by an observer and driver on a motorbike traveling at 10–15 km per hour; observation times alternated between morning (6.00–8.00 am) and evening (4.00–6.00 pm). Intermittent roadkills were also observed by forest officials and drivers, which when verified were included in the totals. For each kill the information recorded included the location, surrounding area (forest, Human habitation, plantation), habitat type, and state & sex of dead animals, which when possible were removed from the road to avoid recounting.

 

The location of the road networks in the Sigur plateau in Mudumalai Tiger Reserve. Samson et al. (2020).

A total of 497 individual Three-striped Palm Squirrels were recorded as roadkill victims in 144 visits covering 5760km, for an encounter rate  of 0.09 individuals/km/month. Most kills were recorded as fresh (307). Males (220) were more frequently observed than females (145), although many were unidentified (132). Three-hundred-andeighty-seven kills were observed over 33 km of road in thorn forest habitats (an encounter rate of 0.08 individuals/km/month), and 110 in dry deciduous forest (7 km; an encounter rate of  0.11 individuals/km/month). More roadkills were recorded in forest habitats (354; an encounter rate of 0.078 individuals/km/month) followed by Human habitation (89; an encounter rate of 0.08 individuals/km/month), and plantations (54;an encounter rate of 0.57 individuals/km/month). The roadkill results show significant variation year by year 2014 (148; 12.33 ± 1.25; an encounter rate of  0.08 individuals /km/ month), 2015 (165; 13.75 ± 1.55; an encounter rate of  0.08 individuals/ km/month), and 2016 (184; 15.33 ± 1.58; an encounter rate of  0.10 individuals/km/month). Month-wise analyses of the roadkills show that May (75; 25 ± 1.15) had more number of roadkills followed by December (61; 20.33 ± 1.76), April (48; 16 ± 1.15), November (47; 15.66 ± 1.45) March (42; 14 ± 1.15), and January (41; 13.66 ± 1.45); and significant variations were observed between month-wise data and the year-wise data. The season-wise data revealed that winter (December–March) (176; 14.66 ± 1.19; an encounter rate of 0.09 individuals/km/month) and summer (premonsoon) (April–June) (156; 17.33 ± 2.12; an encounter rate of  0.11 individuals/km/month) seasons recorded more kills compared to post-monsoon (October–November) (83; 9.11 ± 0.78; an encounter rate of 0.09 individuals/km/month) and monsoon seasons (July–September) (82; 13.83 ± 1.07; an encounter rate of 0.06 individuals/km/month),

 

Male and female roadkill of Three-Striped Palm Squirrel. Sampson et al. (2020).

This study targeted a single species affected by linear construction like road networks. In fragmented habitats, linking route ways enhance the movements of small Mammals. Medium and large-sized Mammals are particularly at risk, especially when the emergence of young coincides with high traffic volumes. Samson et al.'s study shows that males are frequently killed rather than females. Linear construction appears to affect the movement of males and females. Various species show seasonal peaks in accident rates often with a higher percentage of males being killed. This suggests that breeding or dispersal behavior may be partly responsible. Three-striped Palm Squirrel live in diverse habitats but mainly occur in tropical forests and around human habitation. The present study was carried out in two different vegetation structures in Sigur Plateau. Thorn forest had more roadkills compared to dry deciduous forest which indicated that Three-striped Palm Squirrels utilised thorn forest vegetation more. A considerable amount of roadkills was observed in human habitation as well as plantations. Three-striped Palm Squirrels are easily tamed by humans and easily adapt to human habitation, plantations, and gardens. 

Sunbathing is one of the key activities for Striped Squirrel at dawn and dusk. A previous study recorded that most fresh roadkills of Three-striped Palm Squirrel are observed at dawn and dusk in the present study also corroborate the previous study indicating that Three-striped Palm Squirrel use the road surface for sunbathing, it seemed to be the reason for the high death rate. Some incidences may have occurred related to eating the insect on the roads. The road and road allowances attract prey populations, in particular, small Mammals and carrion, but also Insects and Worms that are washed out of the soil onto roads. According to the literature, individuals from this genus prefer Insects as protein sources more than fruits and nuts when fruits and vegetation are in the same proportions.

Winter and summer seasons recorded Three-striped Palm Squirrel roadkills because of very high traffic on the state highway passing through the Nilgiri North Forest Division at one end connected to the Interstate highway NH 67 at Theppakadu and Ooty on other end. Generally, winter and summer are the best seasons to visit Udhagamandalam and that is a reason for high vehicular traffic intensity resulting in the high number of roadkills. Similarly, significant number of roadkills were also found in Mudumalai Tiger Reserve due to local vehicular movement as well as wildlife safaris.

According to the literature, habitat loss and degradation due to agro-industry farming, small-scale logging, Human encroachments, invasive alien species, and hunting for local consumption purposes are minor threats to the Three-striped Palm Squirrel population. The present study explored the current major threat in the present scenario. An urgent long-term study is needed to better understand the impact of roads on the ecology of the Three-striped Palm Squirrel.

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Biswamoyopterus gaoligongensis: A new species of Flying Squirrel from western Yunnan Province, China.

The ability to glide has evolved several times in different Mammal groups, but only one group, the Flying Squirrels, Pteromyini, have a wide distribution, with a high diversity in the tropical regions of South and Southeast Asia and species scattered across cooler regions of Asia, Europe, and North America, hinting at a more diverse and widespread population during warmer climates in the past. There are currently 52 described species of living Flying Squirrels, divided into fifteen genera, with a further thirteen genera known only from fossils. The group reach their maximum diversity in Southeast Asia, the area with the greatest number of described species, though many of these species are very poorly known. The genus Biswamoyopterus currently comprises two species of large Flying Squirrels, both of which were described from a single specimen, one collected in the Namdapha National Park in Arunachal Pradesh, northeast India, and the other from central Laos, with the two sites where members of the genus were found being 1250 km apart.

In a paper published in the journal ZooKeys on 18 July 2019, Quan Li of the State Key Laboratory of Genetic Resources and Evolution at the Kunming Institute of Zoology, and the Kunming College of Life Science of the University of Chinese Academy of Sciences, Xue-You Li, also of the State Key Laboratory of Genetic Resources and Evolution at the Kunming Institute of Zoology, Stephen Jackson of Biosecurity New South Wales, the School of Biological, Earth and Environmental Sciences at the University of New South Wales, the Division of Mammals at the National Museum of Natural History, and the Australian Museum Research Institute, Fei Li of the Kadoorie Farm & Botanic Garden, Ming Jiang and Wei Zhao of the Baoshan Management Bureau of Gaoligongshan National Nature Reserve, Wen-Yu Song, again of the State Key Laboratory of Genetic Resources and Evolution at the Kunming Institute of Zoology, and the Kunming College of Life Science of the University of Chinese Academy of Sciences, and Xue-Long Jiang, once again of the State Key Laboratory of Genetic Resources and Evolution at the Kunming Institute of Zoology, describe a third species of Biswamoyopterus from western Yunnan Province, China, a location approximately half way between the two sites where the genus has previously been observed.

The new species is named Biswamoyopterus gaoligongensis, which means 'from Gaoligong', as the area where the species was discovered is on the eastern slope of the southern Mount Gaoligong. The species is described from two specimens, an adult male collected by the scientists and a second skin and skull of indeterminate sex collected by a local villager. This species is large for a Flying Squirrel, with the adult male having a body length of 44 cm, plus a 52 cm tail, and weighing 1.37 kg. The species is reddish brown, with a yellowish white underside. The ears are white with black tips, and the end of the tail is black.

A specimen of Biswamoyopterus gaoligongensis in the branches of a Daphniphyllum tree at Linjiapu, 10 km to the west of the area where the specimens from which the species is described were collected. Kadoorie Farm & Botanic Garden.

The conservation status of Biswamoyopterus gaoligongensis is unclear, but the species appears to have a low population density and live in a lowland forest close to Human settlements, were it is vulnerable to forest clearance for agriculture and hunting.

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Miopetaurista neogrivensis: A Flying Squirrel from the Miocene of Catalonia.

The ability to glide has evolved several times in different Mammal groups, but only one group, the Flying Squirrels, Pteromyini, have a wide distribution, with a high diversity in the tropical regions of South and Southeast Asia and species scattered across cooler regions of Asia, Europe, and North America, hinting at a more diverse and widespread population during warmer climates in the past. The fossil record appears to support this, with many fossil species described, particularly from Europe, dating back as far as 36 million years ago (Eocene), slightly older than the first fossils of Tree Squirrels, Sciurinae, suggesting that the groups may have arisen separately. However, as with many Mammal groups, these fossils are entirely of teeth, and occasionally small fragments of jaw, which are not particularly distinctive from those of other Squirrels, and studies based upon genetics and molecular clock methods have suggested that the group may be only about 23 million years old (Miocene), and should be placed firmly within the Tress Squirrels, rather than being a separate group.

In a paper published in the journal eLIFE on 9 October 2018, Isaac Casanovas-Vilar of the Institut Català de Paleontologia Miquel Crusafont at the Universitat Autònoma de Barcelona, Joan Garcia-Porta of the Centre de Recerca Ecològica i Aplicacions Forestals at the Universitat Autònoma de Barcelona, Josep Fortuny, also of the Institut Català de Paleontologia Miquel Crusafont at the Universitat Autònoma de Barcelona, and of the Centre de Recherches sur les Paléoenvironnements et la Paléobiodiversité at the Muséum national d’Histoire naturelle, Óscar Sanisidro of the Biodiversity Institute at the University of Kansas, Jérôme Prieto of the Department für Geo- und Umweltwissenschaften, Paläontologie at Ludwig-Maximilians-Universität München, and the Bayerische Staatssammlung für Paläontologie und Geologie, Marina Querejeta of the Bavarian State Collection of Zoology, Sergio Llácer and Josep Robles, again of the Institut Català de Paleontologia Miquel Crusafont at the Universitat Autònoma de Barcelona, Federico Bernardini of the Museo Storico della Fisica e Centro Studi e Ricerche Enrico Fermi and the Multidisciplinary Laboratory at the ‘Abdus Salam’ International Centre for Theoretical Physics, describe the partial skeleton of a Flying Squirrel from the Miocene of Catalonia.

The specimen, and some associated material, were discovered during a palaeontological survey of a bonebed exposed at a site excavated for landfill use at Abocador de Can Mata in Catalonia, and is estimated to be 11.64 million years old, roughly on the boundary between the Middle and Late Miocene. It is referred to the species Miopetaurista neogrivensis, which has previously been described from dental material, and is estimated to have had a living mass of about 1.3 kg.

The fossil Flying Squirrel Miopetaurista neogrivensis. (a) Reconstruction of the skeleton based in the partial skeleton from Abocador de Can Mata. Missing elements are based on extant Giant Flying Squirrel, Petaurista petaurista, and are coloured in blue. (b) Life appearance of Miopetaurista neogrivensis showing the animal ready to land on a tree branch. Coat pattern and colour are based on extant Petaurista species, the sister taxon of Miopetaurista. Casanovas-Vilar et al. (2018).

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Petaurista leucogenys: How the Japanese Giant Flying Squirrel selects its food.

Many arboreal (tree dwelling) Mammals are reliant on leaves as a food for at least part of the year, and some feed exclusively on such fodder. However leaves leaves are difficult food, as, unlike fruits or nectar, these are parts of the plant which the plant does not want eaten, and many plants put considerable effort into making their leaves as unpalatable as possible, minimising the amounts of nutrients stored in the leaves, defending them physically with tough fibres or spines, and packing them with toxins such as phenols or tannins. Leaf-eating Mammals avoid these defences by carefully selecting both which leaves and which parts of the leaves they consume, and choosing different food sources and feeding methods at different times of the year.

The Japanese Giant Flying Squirrel, Petaurista leucogenys, is a large arboreal Rodent (adults often reach 50 cm plus a meter-long tail) with a wing-membrane between its fore- and hindlimbs which enables it to glide between trees. It is found in sub-alpine forests and boreal evergreen forests on Honshu, Shikoku and Kyushu islands in Japan, as well as in Guangdong Province in China. It has a varied diet, which includes a variety of fruits, nuts, and flowers, but also includes leaves. Usefully, it is prone to detaching leaves before partially consuming them, then allowing partially consumed leaves with distinctive feeding traces to fall to the forest floor, where they can be picked up by interested scientists.

In a paper published in the journal Ecology and Evolution on 15 June 2017, Mutsumi Ito of the Department of Biology at Tokyo Metropolitan University, Noriko Tamura of the Tama Forest Science Garden, and Fumio Hayashi, also of the Department of Biology at Tokyo Metropolitan University, describe the results of a three-year study of the leaf-feeding behaviour of the Japanese Giant Flying Squirrel in the Tama Forest Science Garden.

A Japanese Giant Flying Squirrel, Petaurista leucogenys. 飯能に棲むいきものたちのこと.

Ito et al. collected leaves of two Oak species along a 2 km census route between one and five times a month between May 2013 and November 2015. These were the deciduous Sawtooth Oak, Quercus acutissima, and the evergreen Tsukubanegashi Oak, Quercus sessilifolia.

They found that while the leaves of the evergreen Quercus sessilifolia were the preferred food of the Squirrels in winter, they were seldom eaten in summer when the leaves of the deciduous Quercus acutissima were available. The leaves of the evergreen Quercus sessilifolia were almost always eaten apically, i.e. from the tip, while the leaves of the deciduous Quercus acutissima were eaten basally, or centrally, i.e. from the base or centre, with the tip being avoided.

Three types of leaf debris eaten by the Japanese Giant Flying Squirrel (Type A, apically eaten; Type B, basally eaten; Type C, only centrally eaten). The total length (Lt) and width (Lw) of intact leaves are measured, as well as the remaining length for basally (La) and apically (Lb) eaten leaves, and the maximum width of the centrally eaten circle (Ld) of leaf debris. All leaves shown are the evergreen Quercus sessilifolia. Ito et al. (2017).

Examination of the leaves in the laboratory revealed that those of Quercus acutissima had a far higher sugar content that those of Quercus sessilifolia. This explains the preference of the Squirrels for these leaves when they are available, as most Mammals preferentially select food that has a higher sugar content (is sweeter) as this relates directly to the energy available from the food. However, the leaves of Quercus acutissima also have far higher levels of phenols, toxic chemicals that Mammals generally avoid (though this is not the first time that leaf-eating Mammals have been shown to overcome an aversion to leaf toxins if the sugar content is high enough). Importantly the phenols in the leaves of Quercus acutissima were found to be concentrated around the tips of the leaves, which the Squirrels were consciously avoiding, showing that they were capable of adjusting their feeding behaviour to avoid toxins in a seasonally available food.

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Flying Squirrels from the Late Miocene of Catalonia.

Flying Squirrels, Pteromyini, are today represented in Europe by only a single species, the Siberian Flying Squirrel, Pteromys volans, which is found in the Coniferous forests of Russia, Finland and other areas in the northeast of the continent, but in the lowland tropical forests of Southeast Asia as many as six species may be found living alongside one-another, able to co-exist because they occupy slightly different ecological niches. In the much warmer climate of the Miocene, Flying Squirrels are known to have been more numerous and diverse in Europe, with sites in Central Europe producing up to five species, suggesting a similar ecological diversity to that of modern Southeast Asia. However this level of diversity has not been recorded from the Late Miocene of Iberia, where three species have been recorded from Catalonia and none from the rest of the peninsula. This is in keeping with current reconstructions of the Miocene climate of Iberia, which suggests a more arid climate then the rest of Europe, with an intermediate climate in Catalonia, wetter than the rest of Iberia but dryer than most of Europe, a situation that persists to this day.

In a paper published in the journal Palaeobiodiversity and Palaeoenvironments on 8 May 2015, Isaac Casanovas-Vilar of the Institut Català dePaleontologia Miquel Crusafont at the Universitat Autònoma de Barcelona, SergioAlmécija of the Institut Català de Paleontologia Miquel Crusafont at the Universitat Autònoma de Barcelona and the Department of Anatomical Sciences at Stony Brook University and David Alba, also of the Institut Català de Paleontologia Miquel Crusafont at the Universitat Autònoma de Barcelona describe a series of new Flying Squirrel remains from the Late Miocene Can Llobateres 1 site in the Vallès-Penedès Basin of Catalonia, and discuss the implications of these for the climate and environment of Miocene Catalonia.

The Can Llobateres 1 was discovered in the 1920s during a road construction project and has been the subject of intermittent excavations ever since, particularly since the discovery of Ape remains at the site in the 1950s, which resulted in a prolonged collaboration between Spanish palaeontologist Miquel Crusafont and Johannes Hürzeler from the Museum of Basel, during which many tons of sediment were removed and sieved for microfossils, resulting in (amongst other things) a number of Flying Squirrel teeth being recovered in the 1960s. Excavations at Can Llobateres 1 were resumed in 2010 after a 12 hiatus by a team from the Institut Català de Paleontologia Miquel Crusafont, resulting in a number of new Flying Squirrel remains.

In order to determine that a Squirrel was capable of flying (or more technically gliding, since no squirrel can actually fly) it is necessary to be able to reconstruct a reasonable proportion of its post-cranial skeleton. This is not possible to do from any of the Catalan material, which comprises only Teeth, but it is usually possible to assign Rodents to species level from their teeth (as with most Mammals), and all of the Can Llobateres 1 material is assigned to species described elsewhere, enabling either a more complete knowledge of their anatomy or at least a confident assignment to the tribe Pteromyini (Flying Squirrels).

The species Albanensia grimmi, was first described from three cheek teeth from Marktl in Germany in the 1960s. It is distinctive within the genus Albanensia for its large size and the thicker posterolophid and stronger metalophid tooth cusps. In 1970 a partial jaw fragment with two molars and an isolated premolar were described from Miocene sites in the Vallès-Penedès Basin and tentatively assigned to this species, though they were larger than the German material and showed some morphological differences. Since then more specimens of the species have been described from other sites in Europe, notably Rudabánya in Hungary and Götzendorf and Richardhof-Golfplatz in Austria, which have led to a more complete understanding of morphological variation within the species. Due to this the Catalan material is no longer considered to be outside the range of morphological variation for the species, but is still exceptionally large. In addition to the previously described material, Casanovas-Vilaret al. describe a new specimen, a third molar, from Can Llobateres 1. They assign all these specimens to ‘Albanensia aff. grimmi’ (i.e. a member of the genus Albanensia showing affinities with Albanensia grimmi).

A molar of a Flying Squirrel from Can Llobateres 1 showing strong affinities to Albanensia grimmi. Casanovas-Vilaret al. (2015).

The species Miopetaurista neogrivensis was described from La Grive in France in 1970 to describe large members of this genus. In 1991 a single molar assigned to this species was described from Can Llobateres 1. Casanovas-Vilar et al. redescribe this specimen and agree with its taxonomic placement, as well as noting that other specimens of the species have recently been collected from other sites in the Vallès-Penedès Basin, which are likely to have formal descriptions published in the near future.

Second molar of Miopetaurista neogrivensis from the Late Miocene Can Llobateres 1 site in the Vallès-Penedès Basin of Catalonia. Casanovas-Vilar et al. (2015).

The species Miopetaurista crusafonti is well represented at Can Llobateres 1, with 17 isolated cheek teeth and six molar fragments recorded to date. This is considered to be a medium-sized member of the genus Miopetaurista, larger than the numerous species known from earlier Miocene deposits, but not as large as other Late Miocene species such as Miopetaurista neogrivensis, Miopetaurista thaleri and Miopetaurista tobieni. The species was originally described from a fragment of maxilla bearing the fourth premolar and first two molars from the Vallès-Penedès Basin, though this material is stored at the Faculté des Sciences de Montepellier and Casanovas-Vilar et al. have not seen it. The species has been described from several other sites in Catalonia, and may possibly also be present in southern France.

Specimens assigned to Miopetaurista crusafonti from the Late Miocene Can Llobateres 1 site in the Vallès-Penedès Basin of Catalonia. (b) Left fourth premolar, (c) left first or second molar, (d) right third molar collected in 2011, (e) right lower fourth premolar, (f) right first molar, (g) left second molar, (h) right third molar. Casanovas-Vilar et al. (2015).

The species Blackia miocaenica is considerably smaller and simpler than the other Catalan material. The small size and simple morphology of the specimens is considered enough to assign them to the genus, which contains only two species, and the measurements of the specimens place them within the species Blackia miocaenica rather than the slightly larger Blackia woelfersheimensis. The species has previously been recorded from the Early Miocene of Valencia (six million years older than the Can Llobateres 1 deposits), as well as from sites in the Czech Republic, Germany, Switzerland, France, Slovakia, Hungary, Romania and Austria. Casanovas-Vilar et al. report two first molars (one left and one right) of Blackia miocaenica fromCan Llobateres 1, the first time this species has been recorded from the Late Miocene of Catalonia.

Specimens assigned to Blackia miocaenica from the Late Miocene Can Llobateres 1 site in the Vallès-Penedès Basin of Catalonia. (l) Left first molar, (m) right first molar. Casanovas-Vilar et al. (2015).

Finally Casanovas-Vilaret al. report twoworn lower cheek teeth which fall loosely within the size range of two species, the Flying Squirrel Pliopetaurista kollmanni and the Ground Squirrel Spermophilinus bredai (which is also known from Can Llobateres 1). However the specimens have crenulated enamel, a feature associated with Flying Squirrels but not Ground Squirrels, so they are tentatively described as cf. Pliopetaurista sp. (i.e. probably a species of Pliopetaurista).

Specimens assigned to cf. Pliopetaurista sp. from the Late Miocene Can Llobateres 1 site in the Vallès-Penedès Basin of Catalonia. (j) Left fourth premolar (k) right third molar. Casanovas-Vilar et al. (2015).

Several decades of intensive sampling, including the sifting of many tons of sediment for microfossils, have now raised the number of Flying Squirrels found at Can Llobateres 1 to five, comparable with Miocene sites in central Europe and modern lowland forest ecosystems in Southeast Asia, though there is a clear disparity in the frequency of specimens, suggesting that some species were far more common than others.

As well as Flying Squirrels the Late Miocene sediments of the Vallès-Penedès Basin have produced a variety of other Mammals, such as Apes, Tapirs and Rhinoceroses, which indicate a humid forest environment. The sediments have also produced plant fossils such as Reeds, Figs, Palms and Cinnamon Trees, further supporting this environmental interpretation. Middle Miocene sites in Spain have produced evidence of three different ecosystems, herb-dominated wetlands, Legume-dominated woodlands with species such as Casia, Acacia and Caesalpina, indicative of a much drier climate and evergreen Laurel forests which could indicate wetlands or montane forests. Unfortunately most Late Miocene sites in Spain lack sufficient plant material for such interpretations, though sites in the Pyrenees have produced evidence of a mixed flora, with evergreen Laurels alongside more northerly species, such as Alders, Chestnuts, Willows and Elms.

The Late Miocene Vallès-Penedès Basin appears to have been home to wet forests with similarities to those of contemporaneous central Europe, though with a more restricted fauna; many central European species are absent and others, such as Flying Squirrels, were apparently much rarer. A total of five Flying Squirrel species from one site is exceptional, with only a few sites in Germany and France achieving this, but this detection cannot be divorced from the sheer scale of investigations that have occurred at Can Llobateres 1, where decades of excavations have taken place and tons of sediments sieved, and it is likely that many European sites which have produced more samples of common species with much less effort would also produce more species were they subjected to the level of sampling carried out at Can Llobateres 1.

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