Photoperiod synchronizes reproduction and growth in the southern flying squirrel,Glaucomys volans

1990 ◽  
Vol 68 (1) ◽  
pp. 134-139 ◽  
Author(s):  
Theresa M. Lee ◽  
Irving Zucker

Southern flying squirrels were housed in a simulated natural photoperiod for 40°N latitude and held at a constant temperature of 23 °C with food and water provided ad libitum. Body weight and reproductive condition were monitored weekly for 2 years. Males were in reproductive condition between January and mid-August and females were in estrus from late February to mid-April and again from mid-June until early August. Young were conceived during both estrous periods and several squirrels produced two litters in the same year. Minimum body weights were recorded in adults in mid-October each year. Pups born in the spring grew more rapidly than those from summer litters, and reached puberty at 2.5 months as compared with 6–8 months of age for the summer litters. Several seasonal rhythms appear to be controlled by photoperiod in this species.

2021 ◽  
Author(s):  
Jesse F Wolf ◽  
Jeff Bowman ◽  
Sonesinh Keobouasone ◽  
Rebecca S Taylor ◽  
Paul J Wilson

Northern (Glaucomys sabrinus) and southern (Glaucomys volans) flying squirrels are widespread species distributed across much of North America. Northern flying squirrels are common inhabitants of the boreal forest, also occurring in coniferous forest remnants farther south, whereas the southern flying squirrel range is centered in eastern temperate woodlands. These two flying squirrel species exhibit a hybrid zone across a latitudinal gradient in an area of recent secondary contact. Glaucomys hybrid offspring are viable and can successfully backcross with either parental species, however, the fitness implications of such events are currently unknown. Some populations of G. sabrinus are endangered, and thus, interspecific hybridization is a key conservation concern in flying squirrels. We sequenced and assembled a de novo long-read genome from a G. volans individual sampled in southern Ontario, Canada, while four short-read genomes (2 G. sabrinus and 2 G. volans, all from Ontario) were re-sequenced on Illumina platforms. The final genome assembly consisted of approximately 2.40Gb with a scaffold N50 of 455.26Kb. Benchmarking Universal Single-Copy Orthologs reconstructed 3,742 (91.2%) complete mammalian genes, and genome annotation using RNA-seq identified the locations of 19,124 protein-coding genes. The four short-read individuals were aligned to our reference genome to investigate the demographic history of the two species. A Principal Component Analysis clearly separated re-sequenced individuals, while inferring population size history using the Pairwise Sequentially Markovian Coalescent model noted an approximate species split one million years ago, and a single, possibly recently introgressed individual.


Author(s):  
J F Wolf ◽  
Jeff Bowman ◽  
Sonesinh Keobouasone ◽  
Rebecca S Taylor ◽  
Paul J Wilson

Abstract Northern (Glaucomys sabrinus) and southern (Glaucomys volans) flying squirrels are widespread species distributed across North America. Northern flying squirrels are common inhabitants of the boreal forest, also occurring in coniferous forest remnants farther south, whereas the southern flying squirrel range is centered in eastern temperate woodlands. These two flying squirrel species exhibit a hybrid zone across a latitudinal gradient in an area of recent secondary contact. Glaucomys hybrid offspring are viable and can successfully backcross with either parental species, however, the fitness implications of such events are currently unknown. Some populations of G. sabrinus are endangered, and thus, interspecific hybridization is a key conservation concern in flying squirrels. To provide a resource for future studies to evaluate hybridization and possible introgression, we sequenced and assembled a de novo long-read genome from a G. volans individual sampled in southern Ontario, Canada, while four short-read genomes (two G. sabrinus and two G. volans, all from Ontario) were resequenced on Illumina platforms. The final genome assembly consisted of approximately 2.40 Gb with a scaffold N50 of 455.26 Kb. benchmarking universal single-copy orthologs reconstructed 3742 (91.2%) complete mammalian genes and genome annotation using RNA-Seq identified the locations of 19,124 protein-coding genes. The four short-read individuals were aligned to our reference genome to investigate the demographic history of the two species. A principal component analysis clearly separated resequenced individuals, while inferring population size history using the pairwise sequentially Markovian coalescent model noted an approximate species split 1 million years ago, and a single, possibly recently introgressed individual.


2016 ◽  
Vol 130 (3) ◽  
pp. 216
Author(s):  
Louis Lazure ◽  
Patrick Paré ◽  
Nathalie Tessier ◽  
Patrice Bourgault ◽  
Geneviève Dubois ◽  
...  

New records of the Southern Flying Squirrel (Glaucomys volans) in Quebec expand its known range in the province 150 km east to the appalachian foothills and farther west than previously assumed. We obtained individuals through live trapping, trapper collaboration, and opportunistic discoveries. Species identification was confirmed with morphological traits and molecular analysis. individuals were smaller in the eastern part of the province in terms of mass, total length, and tail length. Some live captures also seem to corroborate the fact that Southern Flying Squirrels are mainly associated with mature hardwood forests.De nouvelles mentions du petit polatouche (Glaucomys volans) au Québec permettent d’étendre son aire de répartition connue jusqu’à 150 km à l’est dans les contreforts des appalaches et plus à l’ouest que présumé. Les spécimens ont été obtenus via des captures vivantes, la collaboration des trappeurs et des découvertes opportunistes. L’identification de l’espèce a été confirmée sur des bases morphologiques et moléculaires. Les individus étaient plus petits dans l’est de la province en considérant la masse, la longueur totale et celle de la queue. Les quelques captures d’animaux vivants semblent corroborer que le petit polatouche est davantage associé, au niveau de l’habitat, aux peuplements de feuillus matures.


Author(s):  
Nguyen Vu Son ◽  
James Kenn Chambers ◽  
Makoto Nakata ◽  
Yagutsu Miwa ◽  
Hiroyuki Nakayama ◽  
...  

1989 ◽  
Vol 256 (4) ◽  
pp. R939-R945
Author(s):  
N. J. Kenney ◽  
J. N. Kott ◽  
N. Tomoyasu ◽  
A. J. Bhatia ◽  
A. S. Ruiz ◽  
...  

This study examined the effect of intragastric force-feeding of a milk diet on body weights of rats with lesions of the area postrema/caudal medial nucleus of the solitary tract (AP/cmNTS). Force-feeding was conducted over the first 10 days after the ablation. Body weight was monitored both during and after force-feeding. Food intake was measured during all ad libitum feeding periods. During force-feeding, rats with AP/cmNTS lesions gained weight at the same rate as force-fed sham-lesioned rats or sham-lesioned rats that voluntarily ingested an equal amount of the milk. When returned to ad libitum feeding, lesioned rats that had been force-fed were not hypophagic and did not lose weight. Body weights of such rats remained above those of lesioned rats that were not force-fed and similar to those of nonlesioned rats throughout this study. Despite their normal weights, preliminary analysis indicated that body fat of the force-fed lesioned rats may have been reduced. These findings suggest that the effects of AP/cmNTS ablation are multiple and that reduction of body weight need not be the primary effect of such lesions.


1979 ◽  
Vol 28 (3) ◽  
pp. 297-307 ◽  
Author(s):  
J. F. Quirke

ABSTRACTGroups of spring-born Galway (G) and Fingalway (F) ewe lambs were fed a concentrate diet either ad libitum (H) or at a restricted level (L) during the period 25 July to 16 October 1974 in order to induce differences in body weight at the start of the breeding season. The mean live weights of the GL, GH, FL and FH groups on 16 October 1974 were 37·8 ± 1·3, 44·6 ± 1·3, 35·1 ± 1·1 and 41·9 ± 1·2 kg respectively. More than 95% of the lambs in all four groups attained puberty before 28 February 1975. Galway ewe lambs reached puberty later in the breeding season and were older and heavier at puberty than Fingalways. Animals fed ad libitum were heavier at puberty and attained puberty earlier in the season and at a younger age than those on the restricted feeding regime.Both conception rate and litter size were lower in Galways than Fingalways. There was no evidence of any effect of the nutritional treatments on conception rate or litter size. The mean body weights at puberty for ewes which lambed and those which were barren were 41·9 ± 0·49 and 41·5 ± 0·78 kg respectively. The birth weight and growth rate of the progeny of the ewe lambs was similar for the two breeds and was not influenced by the previous nutritional treatment of the dams. The total lamb mortality between birth and weaning was 40·3%, and 72% of all deaths occurred within 48 h of birth. Losses among twins (48%) were particularly heavy.


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