> tail(bust)
      labels bird.ID Habitat      NDVI      path      roads power_lines hunting Dist.same.behav
24919     ly  Acc_13     irr 0.4086673 119.44207  119.99938    1964.122       1        44.80921
24920     fd  Acc_13     irr 0.2963490 242.56492  242.56493    1964.900       0        28.36691
24921     al  Acc_13     irr 0.4086673  86.60293   89.37999    1972.444       1        63.04002
24922     al  Acc_13     irr 0.1651420 478.82672  478.82672    1978.337       0       238.20707
24923     ly    LB_3     O&P 0.2626982 318.59078 2048.31177    1987.864       0       455.61479
24924     ly  Acc_13     irr 0.4086673  79.84049   83.54124    1999.566       1        15.61776



> str(bust)
'data.frame':   24924 obs. of  9 variables:
  labels         : Factor w/ 4 levels "al","fd","ly",..: 3 3 3 3 3 3 3 3 3 3 ...
  bird.ID        : Factor w/ 13 levels "Acc_11","Acc_13",..: 8 8 8 8 8 8 8 8 8 8 ...
  Habitat        : Factor w/ 7 levels "irr","non.irr",..: 1 1 1 1 1 1 1 1 1 1 ...
  NDVI           : num  0.336 0.336 0.336 0.336 0.336 ...
  path           : num  261 268 271 258 261 ...
  roads          : num  1342 1344 1337 1350 1342 ...
  power_lines    : num  NA NA NA NA NA NA NA NA NA NA ...
  hunting        : int  1 0 1 0 0 0 0 0 0 1 ...
  Dist.same.behav: num  0.173 1.126 3.477 0.173 0.173 ...

birds<-mlogit.data(bust, choice="labels", shape="wide",varrying=NULL, sep=",", id.var = "bird.ID")

mod1 <- mlogit(labels ~ 1 |Habitat+NDVI + path*power_lines*hunting,reflevel="rs", data= na.omit(birds), R=100, halton=NA,rpar=list("rs:bird.ID"="n","ly:bird.ID"="n","fd:bird.ID"="n","al:bird.ID"="n"), panel=F)

Error in solve.default(H, g[!fixed]) :
  Lapack routine dgesv: system is exactly singular: U[10,10] = 0

Error in gmnl(labels ~ 0 | Habitat + NDVI + path * power_lines * hunting |  :
  The following variables are not specified in the formula:  bird.ID