Survival Model Comparisons
Our first model set assessed if capture type affected 3-month survival.
Our top 3-month survival model was S(Capture), which accounted for a
moderate amount of model weight (wi = 0.44; Table
3) and indicated that capture type affected survival. Overall survival
was 0.78 (95% CI = 0.700 – 0.842) with neonates captured via VITs
displaying decreased survival (S = 0.62, 95% CI = 0.487 – 0.740)
compared to neonates captured opportunistically (S = 0.84, 95% CI =
0.753 – 0.905). Neonates captured using VITs were younger
(\(\overset{\overline{}}{x}\) = 1.8 ± 2.7 days, n = 58) than
opportunistically captured neonates (\(\overset{\overline{}}{x}\)= 6. 0
± 3.1 days, n = 97; F1,153 = 71.170, p
< 0.001). Estimated birth mass for neonates captured using
VITs was greater (\(\overset{\overline{}}{x}\)= 3.2 ± 0.9 kg, n = 58)
than estimated birth mass for opportunistically captured neonates
(\(\overset{\overline{}}{x}\)= 2.8 ± 1.0, n = 97;F1,153 = 4.529, p = 0.035). S(Canopy +
Precip2) was competing (∆AICc = 1.94,wi = 0.17, S = 0.78, 95% CI = 0.698 – 0.841)
with precipitation during three to eight weeks (β = -0.348, 95% CI =
-0.687 – -0.009) negatively influencing 3-month neonate survival;
however, there was only weak evidence supporting a positive relationship
between canopy cover and survival (β = 0.019, 95% CI = 0.000 – 0.037).
We then excluded capture method from our candidate set of models and
further assessed 3-month survival for neonates captured via VITs only.
S(Int2) was our top model and described 3-month survival varying by
three time intervals (0 – 2 weeks, 3 – 8 weeks, and 9+ weeks) but
carried a low amount of model weight (wi = 0.34;
Table 4) with overall survival being 0.64 (95% CI = 0.507 – 0.755).
Time interval had a positive effect on survival with survival generally
increasing with increased time (0 – 2 weeks, S = 0.46, 95% CI = 0.200
– 0.693, β = 1.065, 95% CI = 0.880 – 1.251; 3 – 8 weeks, S = 0.56,
95% CI = 0.361 – 0.720, β = 1.133, 95% CI = 1.001 – 1.256; 9+ weeks,
S = 0.92, 95% CI = 0.568 – 0.989, β = 1.407, 95% CI = 1.246 –
1.567). S(Canopy + Precip1) was competing but also carried a low amount
of model weight (ΔAICc = 1.91; wi= 0.22). Overall survival for S(Canopy + Precip1) was 0.21 (95% CI =
0.044 – 0.618); however, there was only a weak relationship between
percent canopy cover and survival (β = 0.021, 95% CI = -0.002 – 0.044)
while total precipitation from 0 – 2 weeks of a neonate’s life did not
affect 3-month survival (β = 0.465, 95% CI = -0.012 – 0.942).
Therefore, we considered total precipitation from 0 – 2 weeks of life
as an uninformative parameter (Arnold, 2010).
Our top model describing 3-month survival for opportunistically captured
neonates after excluding capture method from our candidate set was
S(Canopy + Precip1). S(Canopy + Precip1) carried a low amount of model
weight (wi = 0.27; Table 5) with overall survival
being 0.90 (95% CI = 0.693 – 0.973). Percent canopy cover (β = 0.035,
95% CI = -0.013 – 0.082) and total precipitation from 0 to 2 weeks (β
= -0.400, 95% CI = -0.906 – 0.105) did not affect neonate survival.
S(Canopy) was a competing model and carried a low amount of model weight
(ΔAICc = 0.44, wi = 0.21) with an
overall survival of 0.78 (95% CI = 0.655 – 0.872). Percent canopy
cover displayed a weak but positive relationship with 3-month fawn
survival (β = 0.041, 95% CI = -0.007 – 0.088). S(Canopy + Precip2) was
also a competing model but again carried a low amount of model weight
(ΔAICc = 0.57, wi = 0.20).
Percent canopy cover displayed a positive but weak relationship with
3-month neonate survival (β = 0.039, 95% CI = -0.008 – 0.085) while
there was no relationship between total precipitation from 3 to 8 weeks
and neonate survival (β = -0.342, 95% CI = -0.814 – 0.130).
After excluding capture method from the candidate set of models and
further assessing survival for all neonates combined, regardless of
capture method, S(Canopy + Precip2) was our top model but accounted for
a low amount of model weight (wi = 0.30; Table
6). Overall survival was 0.89 (95% CI = 0.688 – 0.964) with total
precipitation from week 3 to week 8 having a negative effect on survival
(β = -0.348; 95% CI = -0.686 – -0.010). However, there was only a
moderate positive relationship between percent canopy cover and survival
(β = 0.019; 95% CI = 0.000 – 0.037). S(Age) and S(Canopy) were also
competing but also carried low amounts of model weight
(ΔAICc = 1.36, wi = 0.15 and
ΔAICc = 1.89, wi = 0.12,
respectively). Overall survival for S(Age) was 0.65 (95% = 0.517 –
0.767) and was 0.69 (0.593 – 0.786) for S(Canopy). Age positively
affected survival (β = 0.116, 95% CI = 0.016 – 0.215) while percent
canopy cover (β = 0.019, 95% CI = 0.000 – 0.038) displayed a weak, yet
positive effect on survival within their respective models.
S(Canopy + Precip2) was our top model affecting 6-month survival and
accounted for a majority of model weight (wi =
0.75; Table 7). Overall survival was 0.68, (95% CI = 0.587 – 0.759)
with precipitation during 3 to 8 weeks negatively influencing juvenile
survival (β = -0.461, 95% CI = -0.781– -0.142); however, there was
only a moderate relationship suggesting canopy cover positively affected
6-month survival (β = 0.016, 95% CI = 0.000 – 0.033). All other models
were > 2 ∆AICc from our best model in our
6-month survival model set. Mean precipitation from 3 to 8 weeks for
surviving juveniles was 2.9 ± 0.8 cm (n = 84) compared to 3.3 ± 0.9 cm
(n = 41) for juveniles that perished. Mean percent canopy cover at
capture sites for surviving juveniles was ~20 ± 25% (n
= 84) compared to ~11 ± 20% (n =41) for juveniles that
perished. Given capture method was not a top model nor was it competing,
we did not further assess how model selection, survival, and ecological
covariate effects varied among analyses including those captured via
VITs, those captured opportunistically, and all juveniles combined
regardless of capture method.