Weather and landscape factors affect white-tailed deer neonate survival at ecologically important life stages in the Northern Great Plains

Abstract

Offspring survival is generally more variable than adult survival and may limit population growth. Although white-tailed deer neonate survival has been intensively investigated, recent work has emphasized how specific cover types influence neonate survival at local scales (single study area). These localized investigations have often led to inconsistences within the literature. Developing specific hypotheses describing the relationships among environmental, habitat, and landscape factors influencing white-tailed deer neonate survival at regional scales may allow for detection of generalized patterns. Therefore, we developed 11 hypotheses representing the various effects of environmental (e.g., winter and spring weather), habitat (e.g., hiding and escape cover types), and landscape factors (e.g., landscape configuration regardless of specific cover type available) on white-tailed deer neonate survival up to one-month and from one- to three-months of age. At one-month, surviving fawns experienced a warmer lowest recorded June temperature and more June precipitation than those that perished. At three-months, patch connectance (percent of patches of the corresponding patch type that are connected within a predefined distance) positively influenced survival. Our results are consistent with white-tailed deer neonate ecology: increased spring temperature and precipitation are likely associated with a flush of nutritional resources available to the mother, promoting increased lactation efficiency and neonate growth early in life. In contrast, reduced spring temperature with increased precipitation place neonates at risk to hypothermia. Increased patch connectance likely reflects increased escape cover available within a neonate’s home range after they are able to flee from predators. If suitable escape cover is available on the landscape, then managers could focus efforts towards manipulating landscape configuration (patch connectance) to promote increased neonate survival while monitoring spring weather to assess potential influences on current year survival.

Landscape‐scale habitat characteristics and neonatal white‐tailed deer survival

“…The high availability of these crops, combined with a relatively low deer density during the study (~7 deer/km 2 ; K. H. Wiskirchen, Missouri Department of Conservation, personal communication), and similar birth masses to comparable regions (2.56–2.81 kg in South Dakota, USA [Grovenburg et al ], 2.47–4.16 kg in northern Michigan, USA [Duquette et al ]) makes it unlikely that neonate survival was low in the GP because of nutritional constraints. Unfavorable spring and summer weather conditions can also lead to a decline in neonate survival rates (Gilbert and Raedeke , Warbington et al , Michel et al ); however, we did not observe abnormally cold or wet weather during our study. Further, we did not observe higher incidences of natural‐caused mortality, such as disease or abandonment.…”

“…In South Dakota, as in the GP, forests are likely functionally different for neonates than in forest‐dominated systems (i.e., no longer considered cover habitat) because the patches of forest are small and highly fragmented. Michel et al () found that in the Great Plains region, neonate survival was largely influenced by patch connectivity, further emphasizing the importance of landscape configuration and proximity to cover in fragmented systems.…”

“…We defined crop as non‐cover because by the end of May about 85% of all corn crops and 20% of all soybean crops had emerged but were not likely to be tall enough to offer substantial cover to neonates (Grovenburg et al , USDA NASS ). We predicted that as the amount of cover habitat within the home range increased, probability of neonate survival would increase, and the inverse would be true for non‐cover habitat (Rohm et al , Grovenburg et al , Michel et al ). We also predicted that as the complexity of patch shapes increased, neonate survival would increase because of a reduced ability of predators to search complex‐shaped patches (Rohm et al ).…”

“…Among studies that have found a relationship between neonate survival and habitat characteristics at a larger spatial scale, 2 spatial scales have been predominant. Neonate capture locations were either buffered by an average female summer home range size (Van Moorter et al , Grovenburg et al ) or an average neonate home range size (Rohm et al , Grovenburg et al , Jacques et al , Gulsby et al , Michel et al ). Both spatial scales are biologically reasonable because neonates make movements independent of their mother (White et al ) but do so within an area determined by maternal space use (White et al , Ozoga et al , Schwede et al ).…”

Climate change effects on deer and moose in the Midwest

“…In addition to winter climate, spring and autumn weather may also be important for deer populations. Colder temperatures and presence of rainfall in spring have been reported to decrease young fawn survival in some areas, although increased precipitation has been correlated with increased survival (Ginnett and Young , Warbington et al , Michel et al ). Additionally, warmer and wetter weather in spring and autumn have been reported to positively influence deer reproduction, whereas snow in autumn negatively affected survival, possibly because it reduced forage availability at a critical time (Simard et al ).…”