Hanken J, Sherman PW (1981) Multiple paternity in Belding's ground squirrel litters. Hamilton WD (1971) Geometry for the selfish herd. Hamilton WD (1964) The genetical evolution of social behaviour, I and II. Greenwood PJ (1980) Mating systems, philopatry and dispersal in birds and mammals. Am Midl Nat 39:513–596įrench AR (1982) Intraspecific differences in the pattern of hibernation in the ground squirrel Spermophilus beldingi. J Mammal 32:437–449įitch HS (1948) Ecology of the California ground squirrel on grazing lands. ![]() Am Nat 111:782–785Įvans FC (1951) Notes on a population of the striped ground squirrel ( Citellus tridecemlineatus) in an abandoned field in southeastern Michigan. PhD thesis, University of Arizona, Tucsonĭunford C (1977) Kin selection for ground squirrel alarm calls. Anim Behav 30:1183–1192ĭrabek CM (1970) Ethoecology of the round-tailed ground squirrel, Spermophilus tereticaudus. Z Tierpsychol 66:152–164ĭobson FS (1982) Competition for mates and predominant juvenile male dispersal in mammals. Behaviour 76:25–61ĭavis LS (1984) Alarm calling in Richardson's ground squirrels ( Spermophilus richardsonii). Z Tierpsychol 59:338–350Ĭharnov EL, Krebs JR (1975) The evolution of alarm calls: altruism or manipulation? Am Nat 109:107–112Ĭheney DL, Seyfarth RM (1981) Selective forces affecting the predator alarm calls of vervet monkeys. Academic Press, New Yorkīrown CH (1982) Ventroloquial and locatable vocalization in birds. Anim Behav 24:27–35īatschelet E (1981) Circular statistics in biology. ![]() Am Midl Nat 94:468–470īarash DP (1976) Social behaviour and individual differences in free-living alpine marmots ( Marmota marmota). J Mammal 47:440–450īarash DP (1975) Marmot alarm-calling and the question of altruistic behavior. Taken together the data suggest that unlike trills, which increase vulnerability to terrestrial predators (Table 1) and function to warn relatives, whistle directly benefit callers by increasing their chances of escaping from hawks.īalph DM, Balph DF (1966) Sound communication of Uinta ground squirrels. The most frequent callers were animals in exposed positions: far from cover and close to the predatory bird (Table 2). 4), and females' tendencies to whistle were not affected by the presence of relatives, including offspring (Fig. Individuals of both sexes and all ages whistled equally often (Fig. Wild raptors were rarely successful at capturing the rodents once a whistle had been given, and fewer callers than noncallers were killed (Table 1). The sight of a flying hawk and the sound of whistles stimulated widespread calling and running to shelter by the ground squirrels (Fig. Data were gathered on 664 ground squirrel-hawk interactions, most of which were induced by flying trained raptors over individually marked study animals of known sex and age. beldingi at Tioga Pass, California, the adaptive significance of the whistle call was investigated. The animals typically give multiple-note trills to predatory mammals, and single-note whistles to flying hawks. When it is time to reproduce they are able to fill their entire body cavity with eggs (far more than the native bony fish) allowing more young lamprey to be born.Belding's ground squirrels ( Spermophilus beldingi) give acoustically distinct alarm calls to aerial and terrestrial predators. ![]() They are an s-style swimmer which lets them swim with quick bursts of speed allowing them to catch and latch on to fish. They are equipped with 7 gill slits on each side of their body that allows them to bring in water and extract the oxygen even though their mouth is not able to bring in water. Sea Lamprey are so successful because they have a jawless mouth with a large amount of sharp teeth allowing them to latch on to fish and feed. ![]() They feed by latching on to fish and using the teeth on their tongue to drill through the side and feed on the blood. In its natural habitat it will usually not kill fish it feeds from but in the Great Lakes the majority of the fish it feeds on will die as they are not as large. The sea lamprey is a parasite that feeds on the blood of fish. The sea lamprey is an invasive species normally found in the Atlantic Ocean that was able to enter the Great Lakes through man made canals.
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